Pipelines: Emerging Technologies and Design Criteria (Sustainable Oil and Gas Development Series) [1 ed.] 0128206004, 9780128206003

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Sustainable Oil and Gas Development

PIPELINES Emerging Technologies and Design Criteria

M. RAFIQUL ISLAM Emertec Research and Development Limited

Gulf Professional Publishing is an imprint of Elsevier 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, Oxford, OX5 1GB, United Kingdom Copyright © 2023 Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. ISBN: 978-0-12-820600-3 For Information on all Gulf Professional Publishing publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Joseph P. Hayton Acquisitions Editor: Fran Kennedy-Ellis Editorial Project Manager: Helena Beauchamp Production Project Manager: Kamesh R. Cover Designer: Christian J. Bilbow Typeset by MPS Limited, Chennai, India

Summary The central theme of this book is true sustainability in petroleum processing and pipelining. True sustainability requires zero-waste engineering and as such zerowaste engineering form the paradigm for each chapter. Historical developments are critically scrutinized to determine how the sustainability status degraded throughout the modern era ever since the introduction of ubiquitous artificial mass and energy sources. The degradation is captured with the allegorical transition from Honey-Sugar-Saccharine-Aspartame (HSSA)—a process that has maximized profit at the expense of social and environmental collapse. The solutions to the sustainability problem lie in introducing natural products and ultimately natural energy sources. With the premise that only nature is unconditionally sustainable,

current establishment narratives of “green technology” are deconstructed for applications, ranging from separation to pipelines, and from flow assurance to processing and storage. All major theories, involving mass and energy, are examined and their underlying assumptions are exposed. The illogical assumptions are replaced with logical ones to construct mathematical models that are free from paradoxes. These comprehensive models form the basis for sustainable solutions to each problem, from wellhead to storage tank, and then to the pipeline to reach the end user. Centuries-old problems, as related to corrosion, gas hydrate formation, and so on are solved with sustainable technologies. The monitoring technologies are reviewed, and an information gap is identified to guide future research.

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Preface On September 26, 2022, powerful underwater explosions blew gaping holes in the Nord Stream 2 pipelines, which carry Russian natural gas under the Baltic Sea to Germany. Gushers of gas, a kilometer in diameter, are rising to the surface from the blasts, which occurred in Danish waters. Tens of billions of dollars in infrastructure are vital to financing Russia’s economy, and powering and heating the German and European economy lay in ruins. On February 7, 2022, as he stepped up economic and military threats against the Kremlin before the Russian invasion of Ukraine, US President Joe Biden invited German Chancellor Olaf Scholz to Washington for talks. During a joint press conference with Scholz, Biden pledged to destroy the Nord Stream 2 pipeline. “If Russia invades,” Biden said, “then there will be no longer a Nord Stream 2. We will bring an end to it.” Asked how he would do this—as the Nord Stream pipeline is jointly owned by Russia and ostensible NATO allies of the United States such as Germany, France, and the Netherlands— Biden refused to answer, simply saying: “I promise you, we will be able to do that.” Today, we are reminded of Peter Hitchens’ immortal words from 2008, “The next European war will be fought with gas and oil and pipelines.” As the program to crash the global economy continues with the usual suspects reaping unprecedented profits from the process, climate change alarmists are well on track to becoming the most hated persons in history. Meanwhile, genuine

environmental concerns about issues, such as overfishing, chemical waste, air and water pollution, deforestation, and habitat loss, have all but been completely pushed out entirely from the public discourse in favor of obsessing about global warming. In September 2022, UN Secretary-General Antonio Guterres addressed world leaders at the opening session of the General Assembly. It was the first full meeting since 2019, where he addressed that the world is “gridlocked in colossal global dysfunction.” Guterres highlighted the dire financial crises in so many countries; extreme poverty and lack of quality education for children; multiplying conflicts; social media platforms “that monetize outrage, anger and negativity”; and sure enough, the climate emergency. “Our world is in peril and paralyzed,” he implored. There is little doubt, we as a human race are facing an existential threat and our world is quickly reaching the precipice of social collapse. For the first time in human history, the mere survivability of the human race is being questioned, with the very basics of the environment being auctioned with a price tag attached to it. Few would dispute the human race has become progressively more materially advanced with time. Yet, for the first time in human history, an energy crisis has seized the entire globe and the very sustainability of this civilization itself has suddenly come into question. The recent Congresssanctioned report in the United States (U.S. Global Change Research Program, 2017) made it clear that we cannot have good

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environment and good economy at the same time. Only recently, the general public has started to question the establishment narrative. Although the mistrust has often been marginalized as a “conspiracy theory,” there is a need to address the incessant disinformation that comes to light. In this book, fundamental premises of all major theories of mass and energy are scrutinized from a purely scientific perspective. In the modern era, which started with the introduction of ubiquitous artificial mass and energy systems, there has been a superflux of paradoxical systems with each party claiming to be correct, garnering support from whatever branch of power is in power. No other discipline than the energy sector has suffered more from this inherently fallacious cognition pattern. Even though petroleum continues to be the world’s most diverse, efficient, and abundant energy source, due to “grim climate concerns,” global initiatives are pointing toward a “go green” mantra. When it comes to defining “green,” numerous schemes are being presented as “green” even though all it means that the source of energy is not carbon. In fact the “left,” often emboldened with “scientific evidence,” blames carbon for everything, “forgetting” that carbon is the most essential component of plants—the essence of the ecosystem. The “right,” on the other hand, denies climate change altogether, stating that it is all part of the natural cycle and there is nothing unusual about the current surge in CO2 in the atmosphere. Both sides ignore the real science behind the process. In this, both “left” and “right” fail to recognize the fact that artificial chemicals added during practically all industrial processes make the atmosphere all toxic. Starting from a nuclear Hub, Tennessee—a state Al Gore

once represented, the world started to believe carbon is the enemy. This drumbeat against petroleum continued even during the Bush 43 era, and President George W. Bush talked about “oil addiction.” Even his most ardent detractors embrace that comment as some sign of deep thinking. Then came the Obama era—the era of contradictions and paradoxes (Brown and Epstein, 2014). The Trump era is marked by an unprecedented surge in oil and gas production activities that catapulted the United States to energy solvency (Islam, 2022). The growth started in the Obama era; but in a paradoxical move, Obama increased investments in the so-called renewable projects, painting the US administration as environment-friendly, with the fundamental premise that oil is not sustainable but renewable energies, such as solar, wind, and biofuel are. In this book, the fundamental premises of both 97% consensus and 3% dissent views are pointed out. Those premises are connected to demonstrate the fallacies of the schemes that promote “new wave” nuclear energy as the panacea while vilifying natural resources, such as fossil fuel, as “evil.” Every chapter points out what we have collectively done wrong in the modern era and how the current modus operandi has contributed to the current technological disaster and offers solutions that are environmentally attractive, economically sustainable, and technologically innovative. The solutions will not make more money for the corporations or taxhappy big governments, but who said those things have anything with proper science? This book shows how real science is different from dogmatic nonsense that we have been indoctrinated to believe as “science.”

Contents 2.6.5 The implosion of Venezuela and Brazil 98

Preface ix Summary xi

3. Fundamentals of processing

1. Introduction 1

3.1 Introduction 105 3.1.1 Background 105 3.1.2 Chemicals used during refining 111 3.1.3 Role of water, air, clay, and fire in scientific characterization 116 3.2 Comprehensive mass and energy balance 122 3.2.1 Rebalancing mass and energy 122 3.2.2 Energy: toward scientific modeling 123 3.2.3 The law of conservation of mass and energy 125 3.2.4 Avalanche theory 126 3.2.5 Simultaneous characterization of matter and energy 130 3.2.6 Modeling energy spectrum 133 3.2.7 Natural frequency of body parts 141 3.2.8 Disconnection of origins from process 147 3.2.9 Tangible/intangible conundrum or yin
yang cycle 149 3.3 Atmospheric and vacuum distillation 150 3.3.1 Improving distillation 151 3.3.2 Optimization of the distillation process 164 3.4 Refining and gas processing 175 3.4.1 Pathways of crude oil formation 176 3.4.2 Pathways of oil refining 176 3.4.3 Pathways of gas processing 180 3.5 Sustainable development 183 3.5.1 Petroleum refining and conventional catalysts 183 3.5.2 Catalytic cracking 185 3.5.3 Isomerization 186 3.5.4 Reforming 186

1.1 Opening statement 1 1.2 Petroleum processing and separation 3 1.3 Introduction to transportation processes and flow assurances 17 1.3.1 Sampling 18 1.3.2 Analysis 18 1.3.3 Scenario modeling 19 1.3.4 Flow assurance strategies 19 1.3.5 Prevention strategies 19 1.3.6 Remediation strategies 19 1.3.7 Optimization strategies 20 1.4 Introduction to storage 21 1.4.1 Different types of terminals 22 1.4.2 Top 10 global players on storage terminals market 24 1.5 Sustainability status of current technologies 25 1.5.1 Challenges in waste management 32 1.5.2 A novel desalination technique 33

2. Petroleum in the big picture 39 World energy 39 Energy in 2020: the year of COVID 41 New world order 50 What is “green”? 69 2.4.1 Fast-tracking renewables? 76 2.5 Role of oil and gas 79 2.5.1 Environmental impact 92 2.6 Key events and future outlook of oil and gas 93 2.6.1 US energy outlook 93 2.6.2 China’s economic slowdown 95 2.6.3 The Middle East crisis 97 2.6.4 Russia’s expansionism and sanctions

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2.1 2.2 2.3 2.4

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4. Fundamentals of separation of oil and gas 191 4.1 Introduction 191 4.2 Fundamental of surface chemistry 194 4.2.1 Haber process 195 4.2.2 Langmuir adsorption 203 4.2.3 Connection between subatomic and bulk properties 207 4.2.4 The correct formulation 213 4.3 The separation and refining process 220 4.4 Additives and their functions 229 4.4.1 Platinum 229 4.4.2 Cadmium 231 4.4.3 Lead 236 4.5 Benefits of natural chemicals 240 4.6 Science of nanoscale 244 4.7 Zeolite as a refining catalyst 249 4.7.1 Gasoline pool 252 4.7.2 Linear paraffin isomerization 253 4.7.3 Isobutane
butene alkylation 254 4.7.4 Fluid catalytic cracking 255 4.7.5 Reforming 258 4.7.6 Hydrocracking 259 4.8 Restoring science of nature 263 4.8.1 Redefining force and energy 264 4.8.2 Transition of matter from the sun to the earth 268 4.8.3 The nature of material resources 270 4.8.4 The science of water and petroleum 271 4.8.5 Comparison between water and petroleum 275 4.8.6 Contrasting properties of hydrogen and oxygen 278 4.8.7 The carbon
oxygen duality 284 4.9 The science of lightening 291 4.10 Nitrogen cycle: part of the water/nitrogen duality 307

5. Transportation of oil and gas 317 5.1 Introduction 317 5.1.1 Environmental health and safety risks 320 5.1.2 Large pipeline projects 326 5.2 Gas pipeline systems 328 5.3 Historical perspective 331 5.3.1 1850
75—pipelines 332

5.3.2 1876
1900 337 5.3.3 1901
25 339 5.3.4 1926
50 341 5.3.5 1951
75 343 5.3.6 1975
2000 345 5.3.7 2000
present 347 5.4 Heavy crude oil pipelines 350 5.4.1 Viscosity reduction 361 5.4.2 Electrically heated subsea pipelines 379 5.4.3 Pour point depressants 380 5.4.4 Reducing friction 382 5.4.5 Annular and core flow for heavy oil pipelining 387 5.5 Digital networking technologies 392 5.6 Pipeline monitoring system 394 5.6.1 Oil and gas pipeline types 394

6. Advances in pipeline designs 399 6.1 Introduction 399 6.1.1 High-fidelity dynamic sensing 399 6.1.2 Satellites and pipeline safety 400 6.1.3 Carbon capture 404 6.2 Sustainability of CO2 sequestration and storage 411 6.2.1 Carbon backbone 411 6.2.2 Carbon capture and storage for enhanced oil recovery 420 6.2.3 Technoeconomic model 423 6.3 Advances in sensory technologies 442 6.3.1 Exterior-based leak detection methods 450 6.3.2 Pulse echo methodology 458 6.3.3 Fiber optic method 464 6.3.4 Vapor sampling method 469 6.3.5 Infrared thermography 469 6.3.6 Emerging methods 473 6.3.7 Interior/computational methods 481 6.3.8 Dynamic modeling 486 6.3.9 State estimators/observers method 486 6.4 Performance comparison of leak detection technologies 488 6.5 Guideline for pipeline leakage detection method selection 490 6.6 Research gaps and open issues 492

7. Storage of petroleum fluids 497 7.1 Introduction

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7.1.1 US strategic petroleum reserve 502 7.1.2 Natural gas storage 505 7.2 Oil storage 511 7.2.1 Fixed-roof tank 512 7.2.2 External floating roof tank 514 7.2.3 Internal floating roof tank 514 7.2.4 Domed external floating roof tank 514 7.2.5 Horizontal tank 515 7.2.6 Pressure tank 515 7.2.7 Variable vapor pace tank 518 7.2.8 Liquefied natural gas storage tank 519 7.2.9 Contamination 519 7.3 Tankers for oil storage 519 7.4 Gas storage 523 7.4.1 History of “open access” to storage capacity 523 7.4.2 Underground natural gas storage data 525 7.4.3 Storage measures 526 7.4.4 Owners and operators of storage facilities 532 7.4.5 History of “open access” to storage capacity 534 7.4.6 Underground natural gas storage data 535 7.4.7 US demand and supply balance 540 7.4.8 Regional prices 544 7.4.9 Value of storage and storage capacity additions 545 7.4.10 Pipeline capacity 549

8. Fundamental considerations of oil and gas separation 553 8.1 Introduction 553 8.2 Gravity separation 554 8.2.1 Types of oil/water separators 558 8.2.2 Benefits of an oil/water separator 559 8.3 Oil
water separation 561 8.4 Sand jets and drains 587 8.5 Vapor/liquid separation 591 8.5.1 Aerosols 592 8.5.2 Direct numerical simulation of primary atomization 597 8.5.3 Length and time scales 598 8.5.4 Describing the motion of the phase interface 598 8.6 Ideal gas law 600 8.6.1 Internal energy 604

8.7 Subatomic representation 605 8.7.1 Photoemission from atoms, molecules, and solids 609 8.7.2 Ideal gas law in microscopic scale 610 8.8 Reconstituting mass and energy spectrum 620 8.8.1 Conventional classification 620 8.8.2 Galaxy model 624 8.8.3 Useful energy versus harmful energy 631 8.9 Vapor
liquid equilibria 634 8.9.1 Conventional classification of petroleum fluids 636

9. Gas hydrate and its mitigation 643 9.1 Introduction 643 9.2 The importance of natural gas 648 9.3 Natural gas hydrates 657 9.3.1 Natural gas hydrates formation 658 9.3.2 Problems related to the formation of hydrates 661 9.4 Prevention of hydrate formation 665 9.4.1 Thermodynamic inhibitors 667 9.4.2 Low-dosage hydrate inhibitors 667 9.5 Problems with synthetic chemicals 670 9.5.1 Pathways 673 9.5.2 The processing chemicals and natural gas relationship 673 9.6 Proposed solutions 676 9.6.1 First approach 676 9.6.2 Second approach 682 9.6.3 Solar irradiation for hydrate 691 9.7 Emerging technologies 698 9.7.1 Nonchemical approach 698 9.7.2 Chemical approach 702

10. Corrosion and its mitigation 705 10.1 Introduction 705 10.2 Background and historical context 711 10.2.1 Summary of mining and mineral processing 711 10.2.2 The history of mining and mineral processing 713 10.2.3 Pipelines coatings 718 10.2.4 Iron 729 10.3 The science of corrosion 736 10.3.1 Natural protection 743 10.4 Types of corrosion 754

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10.4.1 Atmospheric corrosion 754 10.4.2 Stress corrosion 761 10.4.3 Localized corrosion 780 10.5 Microbially influenced corrosion 793 10.5.1 Background 794 10.5.2 Mechanism of microbially influenced corrosion 796 10.6 Remedy of microbially influenced corrosion 799 10.7 Modeling of microbially influenced corrosion 830

11.3 Chapter 3: Fundamentals of processing 844 11.4 Chapter 4: Fundamentals of separation of oil and gas 844 11.5 Chapter 5: Transportation of oil and gas 846 11.6 Chapter 6: Advances in pipeline designs 846 11.7 Chapter 7: Storage of petroleum fluids 847 11.8 Chapter 8: Fundamental considerations of oil and gas separation 847 11.9 Chapter 9: Gas hydrate and its mitigation 848 11.10 Chapter 10: Corrosion and its mitigation 848

11. Conclusions 841

References

11.1 Chapter 1: Introduction 841 11.2 Chapter 2: Petroleum in the big picture 842

Index 881

849

C H A P T E R

1 Introduction 1.1 Opening statement The evolution of human civilization is synonymous with how it meets its energy needs. Few would dispute the human race has become progressively more civilized with time. Yet, for the first time in human history, an energy crisis has seized the entire globe and the very sustainability of this civilization itself has suddenly come into question. If there is any truth to the claim that humanity has actually progressed as a species, it must exhibit, as part of its basis, some evidence that overall efficiency in energy consumption has improved. In terms of energy consumption, this would mean that less energy is required per capita to sustain life today than, say, 50 years earlier. Unfortunately, exactly the opposite has happened. Only recently, the oil price tumbled to a negative territory ever only to come back up record high under a different us administration. For the oil business, which is used to roller coaster rides in prices, this was a new low and highlights the need for a paradigm shift in managing this valuable resource, which is the driver of modern civilization. The scenario has become more complex by invoking “climate change hysteria,” which is not based on science (Islam and Khan, 2019). With increasing politicization of fossil fuel and ensuing global “climate emergency” agenda, the original thrust of sustainability is all but abandoned, as if petroleum resources cannot be developed sustainably. In this process, a series of so-called renewable technologies have been introduced. These are neither more sustainable nor are they more economic fossil fuel (Chhetri and Islam, 2008). This forced transition has created the single most important energy crisis in US history. This book series on sustainable petroleum development is all about introducing technologies that would render petroleum operations sustainable. Islam and Hossain (2020) presented such technologies for sustainable drilling and Islam (2021) discussed reservoir development, whereas this volume is dedicated to presenting technologies for pipeline and storage of petroleum fluids. In addition, the refining and gas processing technologies are also discussed. A true paradigm shift can be invoked by introducing zero-waste engineering in all aspects of petroleum resource development. The zero-waste mode assures that the proposed recovery mode is sustainable under all scenarios of oil prices. In recent years, Islam and his research group (Islam et al., 2010; Islam and Khan, 2019) have demonstrated that current practices of oil and gas production operations are not sustainable. The principal

Pipelines DOI: https://doi.org/10.1016/B978-0-12-820600-3.00002-0

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© 2023 Elsevier Inc. All rights reserved.

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1. Introduction

impediment to sustainability is the introduction of synthetic chemicals, which are introduced at various levels of oil and gas production. Previously, it has been demonstrated that conventional “renewable” technologies are less sustainable than conventional oil recovery and processing schemes (Islam and Jaan, 2018). In reservoir evaluation and reserve assessment, century-old technologies are used. Fundamental mathematical formulas and scientific description of oil and gas reservoirs have not been updated despite the advent of improved mathematical tools, reservoir, and more accurate scientific models to describe fluid flow through porous media. Fig. 1.1 shows the current technological practices are focused on short-term, linearized solutions that are also inherently unsustainable. As a result, technological disaster prevails practically in every aspect of the post-renaissance era. Petroleum practices are considered to be the driver of today’s society. Here, the modern development is essentially dependent on artificial products and processes. We have reviewed the postrenaissance transition, calling it the honey
sugar
saccharine
aspartame (HSSA) degradation (Khan and Islam, 2016). In this allegorical transition, honey (with a real source and process) has been systematically replaced by aspartame that has both source and pathway that are highly artificial. This sets in motion the technology development mode that Nobel Laureate in Chemistry—Robert Curl called “technological disaster.” Sustainable petroleum operations development requires a sustainable supply of clean and affordable energy resources that do not cause negative environmental, economic, and social consequences. In addition, it should consider a holistic approach where the whole system will be considered instead of just one sector at a time (Islam et al., 2010). In 2007 our research group developed an innovative criterion for achieving true sustainability in technological development (described in Islam, 2021). New technology should have the potential to be efficient and functional far into the future in order to ensure true sustainability. Sustainable development is seen as having four elements: economic, social, environmental, and technological.

FIGURE 1.1

True Nature

MEDIEVAL PRACTICES Non-linearity/ Complexity

Current Practices

“Technological disaster”

Aphenomenal

– Robert Curl (Chemistry Nobel Laureate)

Pipelines

Schematic showing the position of current technological practices related to natural practices.

1.2 Petroleum processing and separation

3

When it comes to pipeline, sustainability lies within the materials used, monitoring technologies employed, and chemicals added in the system. With the refining and gas separation technologies, sustainability depends on operating conditions and energy and mass sources used. Similarly, gas separation technologies rely on chemicals added that must be rendered sustainable in order to develop sustainable technologies.

1.2 Petroleum processing and separation Petroleum resources are principally crude oil (liquid form), tar (semisolid), and natural gas (gaseous form). Crude oil is chemically composed of a complex mixture of hydrocarbons of different gaseous, liquid, and solid states, the total of which may reach more than 17,000 organic compounds. Crude oil varies in appearance depending on its composition, and usually varies in color from black to dark brown (Picture 1.1), often with yellow, red, or green tinges on it. Similarly, viscosity and density both vary according to the composition. For instance, there are types of oil that have a low viscosity (Arabian light with viscosity lower than 1 cP), while other types of oil have a very high viscosity, as high as 100,000 cP (while remaining liquid). Of course, viscosity of tar sand, the semisolid version of petroleum resource would be millions of cP. Crudes are usually classified in terms of their specific gravity as very light, light, median, heavy, and extra heavy. An empirical set of units for the crude gravity, defined by the American Petroleum Institute (API), is currently used in oil industry. Light oils have lower specific gravity and larger API gravity, while for heavy oils, vice versa. Their composition also changes, and so the concentration of those heteroatomic compounds typically increases from light to heavy. The crude oils are also categorized in terms of their chemical composition, as for instance, sour crude oils, those presenting high acidity, paraffinic, naphthenic, and aromatic.

PICTURE 1.1 Crude oil is inherently complex with thousands of components in it.

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1. Introduction

FIGURE 1.2 Optical microstructures of the crude oil tube at two different magnifications: (A) at magnification of 100 3 and (B) at magnification of 400 3 . Pearlite colonies are distributed mostly on ferrite grain corners. The sample is taken from the more corroded area of the tube. Source: From Ranjbar and Abasi (2013).

Crude oil being 100% natural, it is not conducive to standardization and as such are not used directly for any commercial applications. That elicits the need to separate various components into usable products. Any naturally occurring petroleum would also contain varying amounts of sulfur, trace amounts of radioactive, and heavy metals. Historically, new science studies single component, followed by two-, three-, and multicomponent fluids. This is not scientific and it does not follow the natural sequence of any fluid. Fluids in nature remain in balance with numerous components and the conventional way of breaking them down is typically an unsustainable approach. However, historically, separation of crude oil into purer and homogeneous components is synonymous with the petroleum industry. The complexity in crude oil microstructure within a rock/fluid system is shown in Fig. 1.2. However, when it comes to utilization, crude oil and natural gas are only useful in their homogenous form (Fig. 1.3). Produced oil is separated into oil, water, and gaseous phases. This is typically done at the oilfield site. Natural gas, on the other, is processed so undesired components, such as water, carbon dioxide, and sulfur compounds. Most gas separation plants are away from gas wells in order to maximize capacity of the plant, as it is not profitable to place a gas separation plant of small operations. The purpose of gas processing is to stabilize the lightest process stream by removing gaseous hydrocarbons and then to separate the various fractions of hydrocarbon gases. Separation is accomplished by a series of distillation and absorption operations. The particular recovery scheme applied depends primarily on the desired purity. Gas processing can be a simple operation producing fuel gases composed of n-butane, more volatile hydrocarbons, and a light naphtha or a complex one that produces a wide range of individual gaseous and light hydrocarbon products. The feed is a light, sweet gas that comes from various processing units. Units that can directly or indirectly provide the feed gas are crude distillation, hydrodesulfurization, catalytic

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1.2 Petroleum processing and separation

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FIGURE 1.3 Molecular structure of refined petroleum products.

cracking, catalytic reforming, thermal cracking, and hydrocracking. The operating conditions depend on the products being recovered. Temperatures as low as 273 C are required to obtain an ethane fraction, and high pressures, about 360 psi, are used in absorbing propane. Fig. 1.4 shows a schematic of an NGL production unit. NGL extraction and methane stripping are based on a proven GSP1 concept with two side reboilers (streams a and b in Fig. 1.4). High ethane recovery can be achieved using part of the NRU column bottoms as additional reflux. This feature compares in efficiency to an RSV2 design, but avoids additional load to the sales gas compressor. The operating pressure of the demethanizer has to be kept at 30 bar (450 psia) or higher to establish the correct operating conditions in the subsequent NRU column. Nitrogen rejection unit (NRU) is shown on the right-hand side in Fig. 1.4. As explained above, a double-column design is not desirable, as the nitrogen/ helium fraction would require compression upstream of the helium purification and liquefaction step. Thus, a well-proven and easy-to-operate single-column concept has been chosen. Instead of taking part of the NRU column bottoms as overhead condenser refrigerant, a side draw behind a partition wall is selected as refrigerant source. This patented concept minimizes the risk of refrigerant contamination with CO2 or C21

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1. Introduction

FIGURE 1.4 NGL (natural gas liquid) and NRU (nitrogen rejection units) section of the integrated gas processing plant.

components, which might cause operational problems in the cold end of the plant. If the CO2 content in the feed gas is below a certain threshold, an amine system can be avoided completely. The perceived power consumption disadvantage of a single column versus a double-column concept is offset by the integration of a side condenser for the NRU column, which unloads the recycle compressor significantly. The nitrogen/methane separation inside the NRU column is driven by a heat pump system (blue lines, in colour, or light grey in black and white Fig. 1.4), in which the high pressure fluid is condensed in the NRU column reboiler and vaporized at two different pressure levels in the side condenser and the overhead condenser. In terms of economics, oil refining plays the greatest role in value addition. The refining industry began in the mid-19th century, soon after oil well drilling industry had been established. Ever since, refining industry has been playing a vital role in supply of energy,

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1.2 Petroleum processing and separation

lighting, transportation, or new materials to improve the quality of life (Larraz, 2021). Oil refining is the process that employs distillation columns so desired components can be extracted from crude oil. Refining is intended to separate the crude oil into its original components and molecules through fractional distillation and rearrange them to be groups that differ from those in the crude oil, i.e., manufacture them into usable final products. These products are as follows: fuels of various use (gasoline, diesel, kerosene, etc.), solvents, lube oils, ingredients for plastic manufacturing, and others. The different classes of hydrocarbon molecules comprise paraffins, olefins, cycles, aromatics, resins, asphaltenes, and other polyunsaturated molecules. In addition to hydrocarbons, crude oils also contain nonhydrocarbon compounds. They include various amounts of sulfur (S), nitrogen (N), oxygen (O), and heavy metals (Fig. 1.5). Fig. 1.6 shows the evolution in refining technology over early 20 century. Little changes in terms of concept have been added after that initial stage of technology development.

FUEL GAS

FUEL GAS

LIGHT GASES

LIGHT GASES

NAPHTHA

NAPHTHA

GASOLINE

GASOLINE

KEROSENE

KEROSENE

LAMP OIL/ STOVE OIL

ATMOSPHERIC GAS OIL

DISTILLATE FUEL OIL

CRUDE OIL

ATMOSPHERIC GAS OIL CRUDE OIL THERMAL CRACKING

RESIDUAL FUEL OIL

ATMOSPHERIC RESIDUUM

LAMP OIL/ STOVE OIL

(A) 1910

DISTILLATE FUEL OIL

THERMAL GASOLINE

ATMOSPHERIC RESIDUUM

RESIDUAL FUEL OIL

(B) 1920 FUEL GAS

LIGHT GASES

GAS RECOVERY

POLY GASOLINE

C3/C4 OLEFINS CATALYTIC POLYMERIZATION

NAPHTHA GASOLINE

KEROSENE STOVE OIL OLEFINIC GASES

ATMOSPHERIC GAS OIL DISTILLATE FUELS

CRUDE OIL THERMAL CRACKING VACUUM GAS OIL VACUUM DISTILLATION

THERMAL GASOLINE CRACKED FUEL OIL VACUUM RESIDUUM

TO COKING, VISBREAKING, ASPHALT PRODUCTION

RESIDUAL FUEL OIL

(C) 1930 FIGURE 1.5 Refinery configuration evolution in (A) 1915, (B) 1920, and (C) 1930. Source: Reproduced from U.S. Petroleum Refining: Meeting Requirements for Cleaner fuels and Refineries. Appendix C. History and Fundamentals of Refining Operations, National Petroleum Council, 1993.

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1. Introduction

Simplified Refinery Flow Diagram

Chemicals Gasses

LPG

Burn as refinery fuel

Gas Disllaon and Purificaon

Propane/butane

SR Gasoline

Gasoline

Naphtha

Catalyc Reformer (CRU) Naphtha and Disllate Hydrotreater

Kerosene

Jet fuel/#F.O.

Diesel

Diesel

Gas Oil

Gas Oil Hydrotreater

Fluid Catalyc Cracking (FCC)

Residue

Delayed Coker

Disllate Hydrotreater

AV gas

HF Alkylaon

Petroleum Coke

FIGURE 1.6 Simplified refinery flow diagram.

FIGURE 1.7 Two mainstream refining approaches to maximize the production of chemicals: steam cracking centered process (A) and fluid catalytic cracking centered process (B). From Alabdullah et al. (2020).

Fig. 1.7 shows two different refining approaches that evolved since the original conception a century ago. Although steam crackers have been traditionally used to process light hydrocarbons, operation under harsher conditions allows the processing of much heavier feedstocks.

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1.2 Petroleum processing and separation

TABLE 1.1 Steam cracking yields obtained using several heavy feedstocks. Feedstock

Conditions 

Yield C2H4 (wt.%)

Yield C3H6 (wt.%)

Yield BTEX (wt.%)

VGO

Tfurnace 5 775 C

17.8

12.6

3.6

Pretreated VGO

steam/oil (w/w) 5 0.75

29.2

19.5

3.9

Alaskan crude

Tfurnace 5 829 C

19.3

12.2




20.4

12.1






Tfurnace 5 843 C Arabian light

steam/oil (w/w) 5 1.2 18

13.8

5.5

Agbami crude (clean crude)

steam/oil (w/w) 5 1

23.5

12.9

8.4

Hydrowax

Tfurnace 5 820 C

28.0

13.8




Such harsher conditions can be achieved through high temperature and/or newer catalysts. Table 1.1 summarizes recent examples where yields of ethylene and propene of up to 23 and 13 wt.% can be achieved by directly feeding full-range pretreated crudes. Although very attractive, to maximize yields to chemicals, recent patents suggest the individual processing of the heaviest and lightest components: the lightest fraction of crude is directly steam cracked, while the heaviest part is first hydrotreated and then cracked in a steam cracking unit. The resulting residue is hydrocracked and recycled to the steam cracker (see Fig. 1.7A). By-products from the separation zone (pyrolysis fuel oil) and hydrogen are recycled after separation. Following this integrated approach, about 60% crude oil conversion to light olefins has been reported, with 29 and 20 wt.% yield of ethylene and propylene, respectively. The main limitations of this approach are the low propylene-to-ethylene ratio and the very high energy consumption (and therefore significant CO2 emissions). In contrast to noncatalytic routes, the use of catalytic crackers (the best known unit being the fluid catalytic cracking [FCC]) allows for a better control over product selectivities. Table 1.2 shows the evolution in the refining process over the years. The types of catalysts used have become progressively more toxic. At present, gasoline with antiknocking characteristics is made with catalytic cracking of heavy hydrocarbons of selective catalysts and zeolites. Gasoline with low aromatic content (benzene/naphthalenes) comes from alkylation of light olefins with isobutane in the presence of hydrogen and metallic catalysts. The catalytic addition of hydrogen to atmospheric tower fractions results in the removal of sulfur and nitrogen and unsaturated compounds (olefins) via the hydrotreating process. Increases in fuel octane numbers come from catalytic reforming and isomerization processes both of which are also catalytic in nature. Upgrading of heavy hydrocarbon streams through hydrocracking into lighter hydrocarbon molecules is catalytic. Tables 1.3 and 1.4 below provide a selection of catalyst poisons by structure and catalyst type.

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1. Introduction

TABLE 1.2 Important process developments in petroleum refining. Year

Process

Operation

1910
15

Thermal cracking

Change gas oil to gasoline

1916

Sweetening

Eliminate mercaptans

1925
29

Vacuum distillation

Produce lubricating oils, change residues to cracking stock and bitumen

1926
29

Alkyllead production

Improve octane number

1930

Thermal reforming

Improve octane number

1932

Hydrogenation

Remove sulfur

1932

Coking

Produce lighter products from residues

1933

Solvent extraction

Improve viscosity index

1935

Solvent dewaxing

Improve pour point

1935

Catalytic polymerization

Increase gasoline yield, improve octane number

1939

Catalytic cracking

Increase gasoline yield, improve octane number

1939

Visbreaking

Reduce quantity of residue

1940
43

Alkylation

Increase gasoline yield, improve octane number

1950

Propane decarbonizing (deasphalting)

Increase cracking stock

1952

Catalytic reforming

Improve octane number

1954

Hydrodesulfurization

Remove sulfur

1956

Inhibitor sweetening

Remove mercaptans

1957

Catalytic isomerization

Improve octane number

1960a

Fluid catalytic cracking

Increase gasoline yield

1961a

Catalytic hydrocracking

Increase gasoline yield

1965a

Molecular sieve catalysts

Increase gasoline yield

1974a

Catalytic dewaxing

Improve pour point

1975a

Residue hydrocracking

Reduce quantity of residue

a

From Royal Dutch/Shell Group of Companies (1983). Adapted and updated from Nelson (1960); cDates are approximate year of commercialization of the process. From IARC (1989). b

The primary effect of low levels of poisons is often the precursor to significant changes in catalyst activity and structure. Poisons may simply lie on the surface of the catalyst and physically block access to the larger inner pore surface or be strongly adsorbed onto the reaction sites and change the physical structure of the surface. Changes in the surface structure are often seen in the changes to activity and selectivity of the catalyst.

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1.2 Petroleum processing and separation

TABLE 1.3 Poison by structure (Website 1). Chemical type

Chemical

Reaction

Group VII and VIA

N, P, As, Sb, O, S, Se, Te

Through s & p orbitals

Group VIIA

F, Cl, Br, I

Through s & p orbitals

Heavy metals

As, Pb, Hg, Bi, Sn, Cd, Co Fe

Occupy d orbitals

TABLE 1.4 Poison by selective catalyst (Website 1). Catalyst type

Reaction

Poisons

Silica, alumina, zeolite

Cracking

Organic bases, hydrocarbons, heavy metals

Nickel, platinum, palladium

Hydrogenation

S, P, Hg, Zn, As, Pb, NH3, halides

Nickel

Steam Reforming

H2S, As

Nobel metals

Hydrocracking

NH3, S, Se, Te, P

Cobalt/molybdenum sulfides

Hydrocracking

Asphaltenes, Nitrogen Compounds, Ni, V, Si, As

For any refining process to be sustainable, one must endeavor to replace poisonous catalysts with natural ones. During the transition from the current unsustainable to total sustainability, new technologies can be integrated with existing technologies. Also, while recycling is not a sustainable solution, recycling/treatment of limited resources (water, hydrogen) and integration of more intelligent control systems should be also considered to reduce both environmental impact and operating costs, at least during the transition phase. At standard conditions of pressure and temperature the light hydrocarbons with carbon numbers 1 to 4 (methane, ethane, propane, butane) are present in gaseous form. Whereas pentane and the heavier hydrocarbons are found in liquid form, and in the heavy fractions with higher boiling points the hydrocarbons are in solid form. The ratio of gaseous, liquid, and solid components depends on the conditions and the phase diagram of the subsurface oil mixture. The hydrocarbons in petroleum are composed predominantly of linear alkanes and to a lesser extent of cycloalkanes and aromatic hydrocarbons; with a small percentage of aromatic compounds containing heterogeneous atoms of nitrogen, oxygen, and sulfur, in addition to trace amounts of metals such as iron, copper, nickel, and vanadium. Many oil tanks also contain live bacteria in their mixtures. The exact molecular composition of crude oil varies greatly depending on the mixture from one place to another, but the difference in the proportion of chemical elements in the mixtures is relatively small. Fig. 1.8 shows how US crude distillation capacity has fluctuated in recent years. The price difference between the price of crude oil and the wholesale price of a refined petroleum product reflects the value of refining crude oil. This difference, known as the crack spread, can indicate refining margins and profitability. Crack spreads for both diesel and gasoline increased in the first several months of 2022. Most recently, gasoline and diesel prices and crack spreads are well above historical averages in response to several factors including

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1. Introduction

FIGURE 1.8 US atmospheric crude distillation capacity (2012
21).

• • • •

Low inventories for both petroleum products in the United States and globally. Fuel demand increases to near prepandemic levels. Relatively low refinery production of both fuels compared with prepandemic levels. Reduced petroleum product exports from Russia.

In response to these high prices, it is expected that refinery utilization will reach a monthly average level of 96% several times in the summer of 2022. EIA measures refinery capacity in two ways: barrels per calendar day and barrels per stream day (b/sd). Calendar-day capacity is the operator’s estimate of the input that a distillation unit can process in a 24-hour period under usual operating conditions, taking into account the effects of both planned and unplanned maintenance. Stream-day capacity reflects the maximum number of barrels of input that a distillation facility can process within a 24-hour period when running at full capacity under optimal crude oil and product slate conditions with no allowance for downtime. Stream-day capacity is typically about 6% higher than calendar-day capacity. The number of operable refineries in the United States (excluding US territories), which includes both idle and operating refineries was 129 at the beginning of 2021, down from 135 at the beginning of 2020. In 2019, the 335,000 b/cd Philadelphia Energy Solutions (PES) refinery in Philadelphia, Pennsylvania, experienced a major refinery incident that led to the refinery’s closure. Because the decision to permanently close the facility was still pending as of January 1, 2020, the facility was listed as idle in the 2020 Refinery Capacity Report. As of January 1, 2021, the refinery is considered closed and is not included in the 2021 report. The additional refinery closures in the 2021 Refinery Capacity Report largely reflect the impact of COVID-19 on the US refining sector (Fig. 1.8). In 2020 the pandemic contributed to a substantial decrease in demand for motor fuels and refined petroleum products, which put downward pressure on refinery margins and made market conditions more challenging for refinery operators. Challenging market conditions, increasing market

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1.2 Petroleum processing and separation

13

interest in renewable diesel production, and preexisting plans to scale down or reconfigure petroleum refineries all contributed to the closing of a handful of refineries in 2020. EIA estimates US refinery inputs will average 16.7 million b/d during the second and third quarters of 2022. This average is lower than the 2019 refinery inputs average of 17.3 million b/d despite high utilization rates because of reductions in refinery capacity since early 2020. US refinery capacity has fallen by almost 1.0 million b/d since early 2020 because several refineries were closed or converted. Despite reduced US refinery capacity in 2020, utilization rates also decreased because of reduced crude oil inputs (Fig. 1.9). The refinery utilization rate (represented as a percentage) measures the volume of gross refinery inputs divided by the total operable crude oil distillation capacity. Crude oil inputs to refineries—also referred to as refinery runs—dropped faster than capacity because even facilities that remained operational were pressured to reduce runs, contributing to a decrease in annual average utilization. The rate declined to an annual average of 79%, the lowest annual level since 1985. Net inputs of crude oil to US refineries averaged 14.2 million barrels per day (b/d) in 2020, the lowest annual refinery runs in more than a decade (Fig. 1.10). In addition to reduced refinery runs, net US imports and production of crude oil also decreased in 2020 compared with 2019. US crude oil production averaged 11.3 million b/d in 2020, the first annual decrease since 2016 but still almost double its 2011 level. US imports of crude oil decreased by approximately 924,000 b/d in 2020 compared with 2019, totaling 1.7 million b/d less oil imported than the average of the previous 5 years (2015
19) (Fig. 1.11). This decrease in crude oil imports likely resulted from lower refinery demand for crude oil in the United States. Conversely, relatively high crude oil production despite lower refinery demand for crude oil contributed to more crude oil

FIGURE 1.9 Per calendar day production for refineries in various regions.

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1. Introduction

FIGURE 1.10 US refinery inputs, capacity, and utilization since 2011.

FIGURE 1.11 US crude oil production, net imports, and inputs to refineries (2011
20).

exports. With lower imports and higher exports, net crude oil imports (imports minus exports) decreased by 1.1 million b/d compared with 2019, averaging 3.4 million b/d less than the average of the previous 5 years. As the United States has increased domestic crude oil production over the past decade, the average density of US crude oil, measured in API gravity, has become lighter.

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1.2 Petroleum processing and separation

15

FIGURE 1.12 Fluctuations in API gravity in US refineries.

Refineries in the United States with substantial secondary conversion capacity, particularly those along the US Gulf Coast (PADD 3), can process denser crude oil grades, which have a low API gravity as well as grades with higher sulfur contents. However, many US refineries (particularly those in the Gulf Coast) are also geographically well positioned to take advantage of increasing US domestic crude oil production. This trend has contributed to the average weighted API of US crude oil inputs increasing to 33.0 in 2020, compared with 32.9 in 2019, 31.5 in 2015, and 30.4 in 2011. Fig. 1.12 shows historical values of API gravity. It shows that the trend in API gravity has changed over the last decade. The emergence of lighter crude I synchronized with post-2008 surge in oil production from shale gas, tight oil, and other unconventional sources. When refined, lighter crude oil grades (with higher API gravity) produce larger yields of more valuable petroleum products such as gasoline, naphtha, distillates, and jet fuel. As a result, lighter crude oil grades often benefit from a price premium compared with heavier grades (lower API gravity), which produce more asphalt and residual fuel oil and tend to sell at a discount. Secondary conversion units, such as catalytic cracking, catalytic hydrocracking, and thermal cracking (or coking) units, enable refiners to transform lowvalue residuals from heavier crude oil grades into more high-value products. West Texas Intermediate (WTI), the US benchmark crude oil grade, has an API gravity of about 40, but many US refiners still import discounted heavier crude oils in order to use secondary conversion units (Fig. 1.13).

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1. Introduction

FIGURE 1.13 US crude oil imports by API gravity (EIA, 2021a, 2012b).

Catalytic cracking, hydrocracking, and coking capacity all decreased as of the start of 2021 relative to the 2020 Refinery Capacity Report. Their decreases range from less than 3% year-on-year for coking to more than 6% for catalytic cracking. These decreases were driven by changes in the operable secondary unit capacity of the current US refinery fleet as well as lower capacity because of decommissioned secondary units from refineries that were no longer operating as of January 1, 2021. The US average regular gasoline retail price increased more than 3 cents to $3.09 per gallon on June 28, 92 cents higher than the same time last year. The Rocky Mountain price increased nearly 9 cents to $3.36 per gallon, the Gulf Coast price increased 5 cents to $2.78 per gallon, the West Coast price increased nearly 5 cents to $3.81 per gallon, the Midwest price increased nearly 3 cents to $2.99 per gallon, and the East Coast price increased nearly 2 cents to $2.98 per gallon. The US average diesel fuel price increased more than 1 cent to $3.30 per gallon on June 28, 87 cents higher than a year ago. The Rocky Mountain price increased 4 cents to $3.43 per gallon, the West Coast price increased 3 cents to $3.84 per gallon, the East Coast price increased nearly 2 cents to $3.29 per gallon, the Midwest price increased nearly 1 cent to $3.24 per gallon, and the Gulf Coast price increased less than 1 cent, remaining virtually unchanged at $3.04 per gallon. US propane/propylene stocks increased by 1.2 million barrels last week to 57.5 million barrels as of June 25, 2021, 11.5 million barrels (16.7%) less than the 5-year (2016
20) average inventory levels for this same time of year. Midwest, Gulf Coast, and Rocky Mountain/West Coast inventories increased by 0.9 million barrels, 0.4 million barrels, and 0.1 million barrels, respectively. East Coast inventories decreased by 0.2 million barrels. EIA expects wholesale prices for gasoline and diesel will begin decreasing in the third quarter of 2022, as refinery production increases. However, wholesale fuel prices will

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1.3 Introduction to transportation processes and flow assurances

17

remain well above previous years through the summer, based on higher crude oil prices as well as the ongoing impact of low global inventories. Low international inventories are likely to face additional tightness in response to the recently announced European ban on Russia’s energy imports.

1.3 Introduction to transportation processes and flow assurances Rarely crude oil is found near a populated area. As such, crude oil produced must be transported to a different location for refining and ultimate utilization. In the present day of increasing hydrocarbon demand, the direction of oil exploration has moved to ever increasing offshore depths and more remote land masses with harsher environments. The flow assurance strategies that are currently being deployed to achieve successful hydrocarbons recovery from these increasing technically challenged areas, increasingly demand an integrated approach to the design of the transportation systems. It is no longer the case that each element of a hydrocarbon development can be designed in isolation. Flow assurance is the process by which fuel production is guaranteed by minimizing restrictions on physical fuel flow. Flow assurance is a new term in the oil and gas industry, originating in the 1990s, and coined by Petrobras. Translated from the Portuguese, this meant “guarantee of flow”—or the ensuring that fluids produced by a fuel reservoir consistently and reliably reach the point of separation into discrete compounds. More recently, the term has come to encompass the entire supply chain, from source to end user. Despite its various definitions in the past 25 years, flow assurance broadly involves the identification of potential oil and gas fields and wells, and the logistics behind transporting any fuels to storage or processing facilities as efficiently as possible. Flow assurance is therefore particularly important (and difficult) with offshore operations. There are a wide variety of techniques that can be employed to limit stoppages to fuel flow. Originally, flow assurance only covered the analysis and evaluation of the problems caused by solids forming in pipelines, but now covers any and all risks associated with maintaining flow. The field is now considered closer to risk management than to avoidance. Managing risks with fuel flow begins whenever the equilibrium of the fuel in question is disturbed, or when the well is sunk and fuel flows out for the first time. From this point onward, whenever oil or gas passes from one stage to another, there is an associated risk of changes in state within the fuel. This will usually involve liquid matter producing gasses, gasses condensing into liquids, or solids forming. Because Petrobras’ original definition of flow assurance was developed whilst working with the high-pressure, low temperature environments of deepwater fields in mind, the theory has developed rapidly alongside the industry’s push into ultra-deepwater fields. To ensure the system operates as expected, the formation of hydrates, wax, asphaltenes, scale, and emulsions must be anticipated, limited, or prevented. Multiphase flows—multiple materials in the same state, such as oil and water in liquid state, or the simultaneous flow of liquid and gas fuel—greatly increase the risk of unwanted formations or emulsification, as do flows where the thermal dynamics of fuel are likely to change.

Pipelines

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1. Introduction

Without a proper viability study of a potential discovery, particularly in a deepwater site, the flow of fuel can remain uncertain until it’s too late to prevent recurrent issues. A properly integrated flow assurance plan includes a full risk assessment, covering • The modeling of multiphase flows and temperature changes. • The projection of hydrate, wax, asphaltene, scale, and emulsion formation. • The interface with other departments and operational processes, such as engineering. If implementing a strategy into a system that is already operational, as is most often the case, a full flow assurance analysis will have to be conducted—from taking fuel samples to implementing a prevention strategy. As with the definitions of flow assurance, the models for prevention strategies vary, but broadly adhere to the following structure: • Sampling—wherein data is collected from fuel samples at various points along the supply chain. • Analysis—taking the raw samples and analyzing them along various criteria, providing more detailed data than in-field sampling alone. • Scenario modeling—during which the data is used in a series of flow assurance scenarios to model various outcomes.

1.3.1 Sampling With huge variance in the properties of oil, gas, and water across the world, and within individual fuel fields, it is vital to ensure that the properties of the fuel in each well are researched, recorded, and updated. Samples should be drawn from various depths using a sampling device lowered into the well, with the device being used to extract samples from the well wall wherever possible. The most difficult part of the sampling process, however, is the transportation of fuel to the testing facility—as any changes in temperature or pressure can alter the state of the fuel and invalidate the sample.

1.3.2 Analysis The analysis of fuel should determine its water composition, from water content by distillation to water and sediment analysis. If a company does not know the water content of its products, then equipment can be damaged by unwanted levels of salinity and moisture, processes will not run at full optimization, and products can fail to meet industry or international guidelines. Testing and analysis should also determine how the fuel behaves when its pressure, volume, or temperature are changed, often called the PVT measure. Another part of the analytic process is the thermal
hydraulic testing process, covering the effects of multiphase heat transfer, fluid mechanics, and thermodynamics. The analysis into multiphase heat transfer can determine the points at which the fuel boils whilst flowing or stagnant, and the critical heat flux point; fluid mechanics testing can establish how the fuel moves and reacts when under different forces; and the thermodynamic tests cover

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1.3 Introduction to transportation processes and flow assurances

19

the state of the fuel through its entire thermodynamic cycle. Most fuel assurance analysis also includes tests for wax appearance, the solubility of asphaltenes, and scanning for additional organic compounds.

1.3.3 Scenario modeling The modeling part of the process transforms data into a picture that can be used to create an actionable flow assurance strategy. The model is built using all thermohydraulic data from the analysis stage and creates a complete picture of how the system functions— from the transient states of start-ups and shutdowns, to normal efficient running. Throughout this process, the number of options for a potential strategy should decrease until an optimal plan remains.

1.3.4 Flow assurance strategies Flow assurance strategies are the bulwark of an efficient operation, encompassing three main approaches—prevention in the first instance, remediation if issues are detected, and optimization strategies to improve overall effectiveness.

1.3.5 Prevention strategies Prevention strategies are the ideal for oil and gas companies, as they should prevent issues from occurring, negate the need for complex and expensive remediation further down the line, and minimize the shutdown time that can occur due to blockages. Maintaining the operation is of utmost importance, and all on-site operators should be fully aware of the procedures required as per the prevention strategy. The strategy should detail what to do in the event of any breakdowns, how to avoid slugging, and the optimal rate of flow. The incorporation of chemicals is a major part of any flow assurance prevention strategy, and any chemical strategy will be aiming for at least 50% efficiency in preventing operation-halting issues. Any chemical intervention requires a thorough evaluation of the package’s performance, and must be easily deliverable upstream of the issue. It is critical that the chemicals themselves do not fundamentally alter the conditions in the pipeline, or react with any other solutions in the fuel. Prevention strategies are incorporated early in the design process of the project in question, and should include all elements of the operational side of things: layout of the assets, the materials and specifications of every pipeline, the requirements of each well, and a breakdown of the organic make-up of the field.

1.3.6 Remediation strategies Remediation strategies can be built into an operation from very early on, usually in the form of mechanisms primed to release a chemical solution into the fuel, or to alter the PVT environment, as soon as any issues are detected.

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1. Introduction

1.3.7 Optimization strategies Optimization strategies technically cover both prevention and remediation plans, but can more broadly be used to describe any strategy that improves the operations side of fuel flow. In addition to the technologies mentioned above, optimization strategies also include • • • • •

Operations forecasting technology—enabling look-ahead. Control systems checking. Auto-pilot systems allowed closed-loop control. Virtual well metering. Additional engineering simulations.

As operators begin to focus more and more on the improvement of safety in production, flow assurance strategies will become ever more vital to the health of the industry— allowing companies to remain efficient and compliant. Combined with the drive to have facilities take up ever smaller areas, and to rely on fewer resources to maintain them, this is the main driver for growth in the flow assurance solutions market. Tiebacks and subsea systems will become more common, and more and more data will be produced at every point of the process. Avoiding the languishing of data in swamps, and creating actionable plans from an abundance of information will be vital in the coming years—and a great opportunity for solution providers to become involved in more projects. Mokhatab et al. (2015) described the six phases for consideration of the flow assurance risk management for pipelines: assessing the risks, defining the mitigation strategies, defining flow operability, finalizing the operating procedures, optimizing system performance, and real-time monitoring. They are as follows: Phase I: Assessing Flow Assurance Risks. This phase is based on laboratory data. Naturally, the sample has to be representative of reservoir fluids, otherwise erroneous conclusions will be made. From the collected samples, producers then consider which tests are critical to enabling the goal of properly evaluating the flow characteristics of the fluid and designing a pipeline system. Water sampling to determine composition extent is also very critical in establishing flow assurance risks. Note that water can invoke corrosion and scaling, as well as hydrate formation. and may be very challenging to perform. zones or the water samples are contaminated by drilling muds (Guo et al., 2005). Phase II: Defining Flow Assurance Mitigation Strategies. How all the flow assurance risks will be mitigated is studied in this Phase II and a high-level mitigation strategy is then developed. In this phase, pipeline operation issues are considered. This is the phase that will dictate what hydrate inhibitor, corrosion inhibitor, etc. to use or what rates should be maintained in order to avoid flow interruptions. Phase III: Defining Flow Operability. Operability is the set of design provisions and operating strategies that ensure the pipeline system can be started, operated, and shut down under all possible operating conditions (planned and unplanned) throughout the system life cycle. Phase IV: Finalizing the Pipeline Operating Procedures. During this next Phase IV, the pipeline system components (e.g., flow line connectors, insulation system, flow line

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1.4 Introduction to storage

21

joints, and valves) are changed from the original design for various reasons, such as different vendors, different materials, and/or different properties, etc. Due to these changes, the corresponding flow assurance mitigation techniques and operating procedures may need to be modified to reflect the changes. Also, even if the components are not modified; the actual manufactured ones may have different thermal
hydraulic properties from the designed ones based upon performance tests conducted on selected components. Phase V: Optimizing System Performance. In this Phase V, the procedures will be modified based upon the actual recorded performance data from the pipeline system. Analysis of such data may identify some requirements that can be beneficially adjusted to optimize the system performance. Phase VI: Real-Time Flow Assurance Monitoring. The last Phase VI describes realtime flow assurance monitoring. In most cases flow assurance problems cannot be completely eliminated due to unpredictable system component failures, unsuitability for operating conditions, faulty operational procedures for some situations, or operator failures/human errors that can occur in real-time operations. Significant efforts are therefore necessary to minimize the occurrence and impact of such failures. In this regard, real-time flow assurance monitoring systems can provide optimum asset management. Real-time monitoring is possibly the most advanced technological development in the pipeline industry. The smart environment relies first and foremost on sensory data from the real world. Sensory data comes from multiple sensors of different modalities in distributed locations. The smart environment needs information about its surroundings as well as about its internal workings. The challenges in the hierarchy of sensor system include detecting the relevant quantities, monitoring and collecting the data, assessing and evaluating data information, formulating meaningful user displays, and performing decision-making and alarm functions. In each of these aspects, significant developments have been made in recent years. Progress has been made to remotely measure different parameters and combining with other real-time data, including well-head and bottom-hole data.

1.4 Introduction to storage As in any commodity, there is aways discrepancy between supply and demand. In order to smooth out these discrepancies, storage of oil and natural gas is essential to petroleum operations. Companies store more when the prices are lower than they would like and withdraw when prices are high. This is equivalent to hoarding and has limitations. Storage facilities play a crucial role in the crude oil and oil products industry. They serve as a logistical midstream link between the upstream (exploration and production) and the downstream (refining) segments of the oil industry. The discrepancy between supply and demand depends on oil price, which is a function of many factors, including politics. The Brent crude oil spot price averaged $105 per barrel (b) in April, a $13/b decrease from March. Although down from March, crude oil prices remain above $100/b following Russia’s full-scale invasion of Ukraine. Sanctions on

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1. Introduction

Russia and other independent corporate actions contributed to falling oil production in Russia and continue to create significant market uncertainties about the potential for further oil supply disruptions. These events occurred against a backdrop of low oil inventories and persistent upward oil price pressures. Global oil inventory draws averaged 1.7 million barrels per day (b/d) from the third quarter of 2020 (3Q20) through the end of 2021. EIA (2022a, 2022b, 2022c) estimates that commercial oil inventories in the OECD ended 1Q22 at 2.63 billion barrels, up slightly from February, which was the lowest level since April 2014. It is expected that the Brent price will average $107/b in 2Q22 and $103/b in the second half of 2022 (2H22). It is projected that the average price will fall to $97/b in 2023. These outcomes, however, depend on the degree to which existing sanctions imposed on Russia, any potential future sanctions, and independent corporate actions affect Russia’s oil production or the sale of Russia’s oil in the global market. Also can affect any EU ban on Russia and the ability of Russia to cope with sanctions, particularly in competition with US dollar-driven global energy trade. In addition, the degree to which other oil producers respond to current oil prices and the effects macroeconomic developments might have on global oil demand will be important for oil price formation in the coming months. Additionally, they support refining businesses by storing end products. Storage terminals are not only used to store primary, intermediate, and end products, but they also facilitate the continuous supply of feedstock to refineries and chemical plants in the processing industry and absorb fluctuations in sales volumes. Each change in the mode of transport requires temporary storage capacities (terminals with tank storage facilities). An efficient oil industry logistics chain would be inconceivable without such infrastructure. The oil storage sector is characterized by sustainable growth, with the business model ensuring recurring revenue and high EBITDA1 margins. Due to the limited direct exposure to commodity prices, the oil storage sector is far less cyclical than the energy industry. As such this asset class is attractive for infrastructure-focused investors. Storage facilities also offer revenue-generating ancillary services. The inflows may vary depending on the demand for such services. These include throughput services, blending, heating, and intertank transfers.

1.4.1 Different types of terminals Many major energy companies and traders own and operate terminal storage facilities to help integrate their upstream or downstream assets into the marketplace. Although the basic capabilities of such terminals are often the same as the ones owned by independent operators, in general, they do not provide storage to third parties. However, by utilizing third-party storage providers, major energy companies can avoid the large capital expenditure required to build their own infrastructure. Independent storage providers have more flexibility and can adjust better to market movements because their storage is accessible to the open market and is used by third parties. 1

EBITDA is short for earnings before interest, taxes, depreciation and amortization. It is one of the most widely used measures of a company’s financial health and ability to generate cash.

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1.4 Introduction to storage

23

TABLE 1.5 The main hub terminals. Ports

Capacity Capacity (million m3) 2008
20

The main players

ARA

38

4%

Vopak, Koole, VTTI, and Oiltanking

Houston

33

4%

Kinder Morgan, Enterprise Products, and Magellan Midstream

Singapore

15

8%

Vopak, Oiltanking, and Universal Group

Fujairah

10

20%

Vopak, ADNOC, Horizon Terminals, Brooge Energy

Edison Investment Research.

Tank storage terminals can be classified as follows (Table 1.5): • Hub terminals: Located near the major oil hubs (Amsterdam
Rotterdam
Antwerp [ARA], Houston, Singapore, and the United Arab Emirates [Fujairah]), where highvolume product flows intersect. • Import/export terminals: Used for storing products that are exported or imported by local companies. • Industrial terminals: Designed as a component of larger complexes of the chemicals industry. The main demand driver for the tank storage industry is the development of the (seaborne) transport volume of oil and oil products. This is determined by total consumption and/or the processing volume of crude oil and oil products and by trade flows. The location of terminal assets is also a significant value driver: the hub terminals are well positioned and are less sensitive to local and regional economic circumstances as their business activity is related to global trade (therefore less volatile and with a lower risk profile). Storage capacity additions are driven by market structure (contango versus backwardation) and do not exhibit a strong correlation with spot oil prices. Currently, there are several capacity expansion projects planned/ongoing in the main trading hubs (listed above). According to Insights Global, total tank storage capacity may increase by c 10% in the next few years (from c 1bn cubic meters of storage capacity in 2020). Contango and backwardation are terms used to define the structure of the forward curve. When a market is in contango, the forward price of a futures contract is higher than the spot price. Conversely, when a market is in backwardation, the forward price of the futures contract is lower than the spot price. If the spread between the prices is large enough to cover storage, finance, and shipping costs, traders can make a profit by buying oil now and selling it on the futures market for delivery later. However, to capitalize on this profit, traders need storage (and transport) capacity. In this scenario, storage rates typically tend to increase, but the fees from ancillary services may fall due to lower utilization of these services. Storage rates tend to fall during backwardation but are balanced by higher ancillary fees since utilization of ancillary services typically rises.

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1. Introduction

The pandemic sharply eroded oil and oil products demand with billions of people facing lockdowns and travel restrictions. This situation intensified in March when Russia and Saudi Arabia could not agree on terms regarding the degree of production cuts required to stabilize the fall in oil prices. Russia then stepped out of the Organisation of Petroleum Exporting Countries and partner countries alliance (OPEC 1 ). This resulted in Saudi Arabia selling highly discounted crude to its international customers, which triggered a free fall in oil prices and resulted in a super contango. The Energy Information Administration (EIA) estimates that global oil consumption decreased from c 100 million barrels per day (mb/d) at the end of 2019 to c 85 mb/d in Q220 (c 91 mb/d in 2020). Oil companies continued to produce, and the resulting oversupply led to a surge in demand for third-party storage capacity. This led to high occupancy rates in the major hubs, putting a premium on free tank capacity. On April 20, 2020, the West Texas Intermediate oil price traded at a negative $37 per barrel as traders ran out of storage facilities at American hub Cushing, Oklahoma. Just over a year on, with market dynamics stabilizing, economies reopening, demand picking up and production cutbacks from OPEC 1 , oil trading, and the storage businesses should stabilize. There is a risk of declining demand for road fuels due to climate policy, improved engine efficiency, and the adoption of electric vehicles. However, we would expect increased demand for the blending of biofuels, hence the need for tank storage (where much of the blending takes place). However, in the event of lower local demand, European refineries could increase their volume of exports, which would increase demand for storage. According to the International Energy Agency, global oil demand is still growing; by 2025 global oil consumption should reach 103.2 mb/d (an increase of 3.5 mb/d from 2019 levels). However, in its Sustainable Development Scenario (consistent with global net-zero emissions by 2070) oil demand declines by 3 mb/d over the same period. A pathway to net-zero emissions globally by 2050 would require even sharper falls. Note that this netzero emission actually means net on carbon balance. As pointed out by Chhetri and Islam, this net zero doesn’t assure sustainability. Chinese national oil companies, such as the Sinopec Group, China National Petroleum Corporation (CNPC), or PetroChina are the biggest players in the global tank terminal operator segment. Royal Vopak is the world’s largest independent storage provider, with services ranging from the storage of chemicals, oils, gases, and LNG to biofuels and vegoils. Other significant European independent operators of tank terminals are Oiltanking (owned by Marquard & Bahls) and VTTI (owned by Vitol: 45%, IFM Investors: 45%, and the Abu Dhabi National Oil Company [ADNOC]: 10%).

1.4.2 Top 10 global players on storage terminals market The United States has a number of large midstream operators, including Kinder Morgan, Buckeye Partners, Magellan Midstream Partners, and Enterprise Products Partners (Fig. 1.14). They are mostly pipeline operators with storage facilities. The main players in Fujairah are the state-owned oil companies: ADNOC and Horizon Terminals.

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140 120

4%

100 80

Number of terminals per company

Marketshare

5%

3%

60 40 20

2% 1% 0%

0

Si

n la el ag n M ho at ar ina M Ch tro Pe ing k an itt O ye n e ga r ck Bu Mo er nd Ki PC CN k pa Vo c pe no

En

FIGURE 1.14

Market share of worldwide storage. Source: TankTerminals.com by Insights Global, Global Tank Storage Assets (2020).

te

rp

ris

e

Pr

od

uc

ts

Market share (%), LHS Number of terminals per company, RHS

Brooge Energy is an independent provider of midstream oil storage and services with its stated differentiation in fast order-processing times and high-accuracy blending services with low oil losses.

1.5 Sustainability status of current technologies Not long ago, any sustainable operation in the context of petroleum engineering was considered Until now, there is no suitable alternative to fossil fuel and all trends indicate continued dominance of the petroleum industry in the foreseeable future (Islam and Khan, 2019). Even though petroleum operations have been based on solid scientific excellence and engineering marvels, only recently it has been discovered that many of the practices are not environmentally sustainable. Practically, all activities of hydrocarbon operations are accompanied by undesirable discharges of liquid, solid, and gaseous wastes (Khan and Islam, 2007), which have enormous impacts on the environment (Islam et al., 2010). Hence, reducing environmental impact is the most pressing issue today and many environmentalist groups are calling for curtailing petroleum operations altogether. Even though there is no appropriate tool or guideline available in achieving sustainability in this sector, there are numerous studies that criticize the petroleum sector and attempt to curtail petroleum activities (Holdway, 2002). There is clearly a need to develop a new management approach in hydrocarbon operations. The new approach should be environmentally acceptable, economically profitable, and socially responsible. The crude oil is truly a nontoxic, natural, and biodegradable product but the way it is refined is responsible for all the problems created by fossil fuel utilization. The refined oil is hard to biodegrade and is toxic to all living objects. Refining crude oil and processing natural gas use large amount of toxic chemicals and catalysts including heavy metals. These heavy metals contaminate the end products and are burnt along with the fuels producing various toxic by-products. The pathways of these toxic chemicals and catalysts show that they severely affect the environment and public health. The use of toxic

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1. Introduction

catalysts creates many environmental effects that make irreversible damage to the global ecosystem. Similarly, the use of synthetic chemicals can render a drilling operation as well enhanced oil recovery operation unsustainable (Islam, 2020). Crude oil is a naturally occurring liquid found in formations on the Earth consisting of a complex mixture of hydrocarbons consisting of various lengths. It contains mainly four groups of hydrocarbons among, which saturated hydrocarbon consists of straight chain of carbon atoms, aromatics consists of ring chains, asphaltenes consist of complex polycyclic hydrocarbons with complicated carbon rings and other compounds mostly are of nitrogen, sulfur, and oxygen. It is believed that crude oil and natural gas are the products of huge overburden pressure and heating of organic materials over millions of years. Crude oil and natural gases are formed as a result of the compression and heating of ancient organic materials over a long period of time. Oil, gas, and coal are formed from the remains of zooplankton, algae, terrestrial plants, and other organic matters after exposure to heavy pressure and temperature of Earth. These organic materials are chemically changed to kerogen. With more heat and pressure along with bacterial activities, oil, and gas are formed. Fig. 1.15 shows the pathway of crude oil and gas formation. These processes are all driven by natural forces. Sustainable petroleum operations development requires a sustainable supply of clean and affordable energy resources that do not cause negative environmental, economic, and social consequences (Dincer and Rosen, 2007, 2011). In addition, it should consider a holistic approach where the whole system will be considered instead of just one sector at a time (Islam et al., 2010). In 2007 Khan and Islam developed an innovative criterion for achieving true sustainability in technological development. New technology should have the potential to be efficient and functional far into the future in order to ensure true sustainability. Sustainable development is seen as having four elements—economic, social, environmental, and technological. Fig. 1.16 shows the different phases of petroleum operations which are seismic, drilling, production, transportation and processing, and decommissioning, as well as their associated wastes generation and energy consumption. Various types of waste from ships, emission of CO2, human-related waste, drilling mud, produced water, radioactive materials, oil Biomass

FIGURE 1.15 Crude oil formation pathway. Source: After Chhetri and Islam (2008).

Decay and degradation Natural processes

Burial inside earth and ocean floors for millions of years Kerogen formation

Bacterial action, heat, and pressure Bitumen, crude oil and gas formation

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Input A B

C D E F G H C D E F G J

B C J

B I K

Output Seismic 20-30 Days

1 2 3 4 5 6

Drilling 3-5 Years

7 8 9 10 11 12

Production 20-30 yr

7 8 9 10 11 12

Transportation

1 3 4 5 13 14

Decomm issioning 4-8 mon

1 2 3 4 5 15

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Seismic Exploration: It is done by generating sonar wave and receiving sounds with geological information. This study takes 20-30 days. Drilling: It composes of installation of rigs, drilling, and casing. Exploratory and devlopment drilling take 3-5 yrs. Production: Depending on the size of the reverse, the production phase can last between 25-35 years. Transportation: Ships, tankers or pipelines are used to bring the oil/gas to onshore refinery. Decommission: CNSOPB guidelines require the preperation of a decommissioning plan. Generally, it takes 4-8 months. Output: 1. Ship source wastes; 2. Dredging effects; 3. Human related wastes; 4. Release of CO2; 5. Conflicting with fisheries; 6. Sound effects; 7. Drilling muds; 8. Drilling cuttings; 9. Flare; 10. Radio-active materials; 11. Produced water; 12. Release of injected chemical; 13. Ship source oil spills 14. Toxic chemical as Corrosion inhibitor 15. Release of metals and scraps Input: A. Sound wave B. Shipping operations C. Associated inputs related to installation D. Water-based drilling muds E. Oil-based drilling muds F. Synthetic-based drilling muds G. Well testing fluids H. Inputting casing I. Cuttings pieces J. toxic compounds K. Explosive

FIGURE 1.16 Different phases of petroleum operations which are seismic, drilling, production, transportation and processing, and decommissioning, and their associated wastes generation and energy consumption (Khan and Islam, 2006).

spills, release of injected chemicals, toxic release used as corrosion inhibitors, metals and scraps, flare, etc. are produced during the petroleum operations. Drilling is a necessary step for petroleum exploration and production. The conventional rotary drilling technique falls short, since it is costly and contaminates surrounding rock and water due to the use of toxic components in the drilling fluids. Conventional rotary drilling has been the main technique used for drilling in the oil and gas industry. However, this method has shown its limits regarding the depth of the wells drilled, in addition to the use of toxic components in drilling fluids. The success of a high-risk hydrocarbon exploration and production depends on the use of appropriate technologies. Therefore, to overcome the limitations of conventional rotary drilling technique, we need to look for other environmentally friendly drilling technologies which may lead to a sustainable drilling operation. Generally, a technology is selected based on criteria such as technical feasibility, cost effectiveness, regulatory requirements, and environmental impacts. Recently, Khan and Islam (2006) introduced a new approach in technology evaluation based on the novel sustainability criterion. In their study, they not only considered the environmental, economic,

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FIGURE 1.17 Direction of sustainable and unsustainable technology (Khan and Islam, 2016).

and regulatory criteria, but investigated sustainability of a technology. “Sustainability” or “sustainable technology” has been using in many publications, company brochures, research reports, and government documents which do not necessarily gives a clear direction. Sometimes, these conventional approaches/definitions mislead to achieve true sustainability. Fig. 1.17 shows the directions of true sustainability in technology devolvement. It shows the direction of nature-based, inherently sustainable technology, as contrasted with an unsustainable technology. The path of sustainable technology is its long-term durability and environmentally wholesome impact, while unsustainable technology is marked by Δt approaching 0. Presently, the most commonly used theme in technology development is to select technologies that are good for t 5 ‘right now’, or Δt 5 0. In reality, such models are devoid of any real basis (termed “aphenomenal” by Khan and Islam, 2016), and should not be applied in technology development if we seek sustainability for economic, social, and environmental purposes. In addition to technological details of an appropriate drilling technology, the sustainability of this technology is evaluated based on the model proposed by Khan and Islam. Fig. 1.18 shows the detailed steps for its evaluation. The first step of this method is to evaluate a sustainable technology based on time criterion (Fig. 1.18). If the technology passes this stage, it would be evaluated based on criteria such as environmental, economic, and social variants. According to Khan and Islam’s method, any technology is considered sustainable if it fulfills the environmental, economic, and social conditions ðCn 1 Ce 1 Cs Þ $ constant for any time, t, provided that, dCnt =dt $ 0, dCet =dt $ 0, dCst =dt $ 0. To evaluate the environmental sustainability, a proposed drilling technique is compared with the conventional technology. The current drilling technologies are considered to be the most environmentally concerning activities in the whole petroleum operations. The current practices produce numerous gaseous, liquid, and solid wastes and pollutants, none of which have been completely remedied. Therefore, it is believed that conventional drilling has negative impacts on habitat, wildlife, fisheries, and biodiversity. For analyzing the environmental consequences of drilling, conventional drilling practices need to be analyzed, which will be continued, chapter by chapter, in this book on sustainability. In conventional drilling, different types of rigs are used. However, the

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FIGURE 1.18 Flowchart of sustainability analysis of a drilling technology. Redrawn Hossain and Islam (2018).

drilling operations are similar. The main tasks of a drill rig are completed by the hosting, circulating, and rotary system, backed up by the pressure-control equipment. A drill bit is attached at the end portion of a drill pipe. Motorized equipment rotates the drill pipe to

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1. Introduction

make it cut into rocks. During drilling, many pumps and prime movers circulate drilling fluids from tanks through a standpipe into the drill pipe and drill collar to the bit. The muds flow out of the annulus above the blowout preventer over the shale shaker (a screen to remove formation cutting), and back into the mud tanks. Drilling muds are composed of numerous chemicals, some of which are toxic, and which are harmful to the environment and its flora and fauna. These issues will be discussed in the drilling mud chapter. The conventional practice in the oil industry is to use different drilling techniques, where huge capital is involved, and which create huge environmental negative impacts. The technology is also more complicated to handle. Therefore, sustainable petroleum operation is one of the important keys for our future existence in this planet. The challenge is seeking sustainability is in taking a fundamentally new approach. It no longer suffices to resort to innovations, these innovations have to be sustainable. In recent years, a unique way has been devised that considers the extent to which oil and gas patents are being leveraged over time by nonpetroleum patents. Just as technologies combine in unique ways over time within the petroleum patent universe, technologies developed by petroleum companies are also cited outside of the petroleum universe. Higher synergies between disparate technologies move them into stronger and more central locations within the broader patent universe. Location in the knowledge network is important, because the more centrally located technologies have a greater chance of quickly incorporating innovations from neighboring technology areas. By way of contrast, technologies that are at the fringe of the knowledge network have fewer chances of bridging into totally new knowledge areas and creating genuinely disruptive innovations. In Fig. 1.19, all patents from 2015 are used to form a map of human knowledge (as embodied by patents). Technologies are circles, and lines appear when technologies draw on each other. In the 2015 example shown below, semiconductor devices, which were among the fastest growing patent area in the oil and gas industry at the time (Growth and volume by technology), connect widely within the patent universe because of their crosssectional applications across industries. Modern civilization is driven by our energy needs. Despite controversies surrounding petroleum operations and their impact on the environment, petroleum resources continue to carry bulk of energy needs. Sustainable development can alleviate environmental impacts and place petroleum operations on a leadership position even for environmental integrity and long-term sustainability (Islam and Khan, 2019). Drilling is the primary operation that connects us to the petroleum resources. As such, it is the most important operation. This technology is a necessary step for both petroleum exploration and production. While drilling engineering is a well-established discipline, the fact that every well is unique makes a drilling operation risky. In the past, risk management due to blowout concerns and safety of personnel have been the primary focus of a drilling operation. Over the last few decades, the concerns over environmental integrity and carbon footprint have overwhelmed petroleum operators. The challenge has been to drill faster, with greater precision in more hazardous areas or more technically challenging depths with minimum environmental damage than ever before. While the background work of planning, involving rock/fluid characterization, environmental impact assessment, and others is team endeavor, the execution of drilling is the

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Systems for controlling or regulang nonelectric variables

Materials for miscellaneous applicaons, not proivided for elsewhere Lime, magnesia

Fluid

Climate change migaon technoligies in the producon or processing of goods

Composions of macromolecular

Coang Pipes

Pipe joints or couplings

Valves

Soldering or unsoldering

Invesgang or analysing materials by determining their chemical/physical propres

Geophysics

Working metallic powder

Cracking hydrocarbon Separaon

Foundaons Earth boring, well treang, and oil field chemistry

Measuring not specially adapted for...

Earth Drilling, E. G. Deep Drilling

Chemical or physical processes, E.G. catalysis,...

Line connectors

Acyclic or carbocyclic

Explosive charges, E.G. for blasng, fireworks, ammunuon

Stock material or miscellaneous Ships or other waterborne vessels

Wells Mixing, E.G., dissolving, emulsifying, dispensing

Joints and connecons Posive displacement machines for liquids

Metal working Alloys

Shaping or joining of plascs

Machine element or mechanism Reducon of greenhouse gases emission, related to energy generaon, transformaon, or

FIGURE 1.19 The central role of drilling technology. Source: From Deloitte (n.d.).

responsibility of the drilling engineer. Drilling petroleum wells continues to be the most daunting task among all engineering undertakings. The most important aspect of preparing the well plan, and subsequent drilling engineering, is determining the expected characteristics and problems to be encountered in the well. A well cannot be planned properly if these environments are unknown. Therefore, the drilling engineer must initially pursue various types of data to gain insight used to develop the projected drilling conditions. If there had to be development of sustainable technologies, the role of “peripheral” technologies becomes clear from Fig. 1.19. The term Energy Innovation Index (EII) was introduced by Deloitte (n.d.) to express the drift in aggregate of innovation within the petroleum industry as a whole by producing a weighted average across all technologies. Technologies with high petroleum contributions and a commanding location in the patent network

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contribute positively toward the O&G aggregate score. When a core technology in the oil and gas industry drifts away from the center of the patent universe, or has a decreasing contribution from the petroleum industry, it causes a decline in the EII. When EII is computed, it shows a slight decline over time. This means that the overall petroleum industry seems to be moving toward the edge of the overall patent universe. This should not be interpreted as a slowdown in the pace of innovation within oil and gas, but rather that other industries have likely accelerated their intensity and interconnectedness of innovation faster over the past decade or so—a decade in which advances in IT and communications technologies have become pervasive. It also reflects the fact that many of the meaningful innovations in the oil and gas industry have come from combining existing petroleum technologies rather than “moon shot” innovations combining more distant technologies. In this context, the monitoring technology is worth a mention. New research findings have helped with accurately predicting pore pressure and fracture gradients, making it possible to advance such technologies as underbalanced, managed pressure, and air drilling with low rheology drilling muds and cements. Now, if the mud and cement system had to be recalibrated based on sustainable development, one needs to reconstruct the EII, because several aspects of the innovations would have contributions from other fields. One of the most important technologies developed in the new millennium is the socalled zipper fracturing. It is a completion methodology commonly executed in many shale developments. It was originally called “simulfrac,” and tested in Barnett shales of United States. Initially, operators implemented zipper fracs to enhance operational efficiency and to reduce cycle time between frac stages through drilling of parallel wells. The objective is to utilize fracture network in creating greater transmissivity. This technology has become popular ever since its first implementation in 2012 and has proven to enhance production as well as ultimate recovery. EII for this technology shows strong trends because this is the technology that has sustainable technologies embedded in it. By 2012, lesser-cited categories such as metalworking (patents comprising of new processes, tools, machines, and apparatus made from metal) had emerged as a key linking technology, or a bridge, between earth drilling and other O&G-related technologies. Combined with its high growth rate of 192% from 2006
15, metalworking has become a technology area that has not only grown in volume but seemingly also in its significance within the oil and gas knowledge network.

1.5.1 Challenges in waste management Drilling and production phases are the most waste-generating phases in petroleum operations. Drilling mud consists of condensed liquids that may be oil- or synthetic-based wastes, and contain a variety of chemical additives and heavy minerals that are circulated through the drilling pipe to perform a number of functions. These functions include cleaning and conditioning the hole, maintaining hydrostatic pressure in the well, lubrication of the drill bit and counterbalance formation pressure, removal of the drill cuttings, and stabilization of the wall of the drilling hole. Water-based muds (WBMs) are a complex blend of water and bentonite. Oil-based muds (OBMs) are composed of mineral oils, barite,

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mineral oil, and chemical additives. Typically, a single well may lead to 1000
6000 m3 of cuttings and muds depending on the nature of cuttings, well depths, and rock types (Khan and Islam, 2007). A production platform generally consists of 12 wells, which may generate (62 3 5000 m3) 60,000 m3 of wastes (Khan and Islam, 2007). Fig. 1.20 shows the supply chain of petroleum operations indicating the type of wastes. The current challenge of petroleum operation is how to minimize the petroleum wastes and their impact in the long term. Conventional drilling and production methods generate an enormous amount of wastes. Existing management practices are mainly focused to achieve sectoral success and are not coordinated with other operations surrounding the development site. The following are the major wastes generated during drilling and production: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Drilling muds. Produced water. Produced sand. Storage displacement water. Bilge and ballast water. Deck drainage. Well-treatment fluids. Naturally occurring radioactive materials. Cooling water. Desalination brine. Other assorted wastes.

The most significant advancement in sustainable petroleum operations has been in the areas of zero-waste engineering (Khan and Islam, 2016). This scheme emerged from petroleum policies from decades ago that required oil and gas companies to investigate no-flare technologies. Bjorndalen et al. (2005) developed a novel approach to avoid flaring during petroleum operations. Petroleum products contain materials in various phases. Solids in the form of fines, liquid hydrocarbon, carbon dioxide, and hydrogen sulfide are among the many substances found in the products. According to Bjorndalen et al. (2005), by separating these components through the following steps, no-flare oil production can be established (Fig. 1.20). Simply by avoiding flaring, over 30% of pollution created by petroleum operation can be reduced. Once the components for no-flaring have been fulfilled, value-added end products can be developed. For example, the solids can be used for minerals, the brine can be purified, and the low-quality gas can be reinjected into the reservoir for EOR.

1.5.2 A novel desalination technique Management of produced water during petroleum operations offers a unique challenge. The concentration of this water is very high and cannot be disposed of outside. In order to bring down the concentration, expensive and energy-intensive techniques are being practiced. Recently, Khan and Islam (2016) have developed a novel desalination technique that can be characterized as totally environment-friendly process. This process uses no

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FIGURE 1.20

1. Introduction

Breakdown of the no-flaring method (Bjorndalen et al., 2005).

nonorganic chemical (e.g., membrane, additives). This process relies on the following chemical reactions in four stages: ð1Þsaline water 1 CO2 1 NH3 -ð2Þprecipitatesðvaluable chemicalsÞ 1 desalinated water -ð3Þplant growth in solar aquarium-ð4Þfurther desalination This process is a significant improvement over an existing US patent. The improvements are in the following areas: • CO2 source is exhaust of a power plant (negative cost). • NH3 source is sewage water (negative cost 1 the advantage of organic origin). • Addition of plant growth in solar aquarium (emulating the world’s first and the biggest solar aquarium in New Brunswick, Canada). This process works very well for general desalination involving sea water. However, for produced water from petroleum formations, it is common to encounter salt concentration much higher than sea water. For this, water plant growth (Stage 3 above) is not

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possible because the salt concentration is too high for plant growth. In addition, even Stage 1 does not function properly because chemical reactions slow down at high salt concentrations. This process can be enhanced by adding an additional stage. The new process should function as: ð1Þ Saline water 1 ethyl alcohol-ð2Þsaline water 1 CO2 1 NH3 -ð3Þprecipitatesðvaluable chemicalsÞ 1 desalinated water-ð4Þplant growth in solar aquarium-ð5Þfurther desalination

Care must be taken, however, to avoid using nonorganic ethyl alcohol. Further value addition can be performed if the ethyl alcohol is extracted from fermented waste organic materials. The process that has the biggest impact on the long-term sustainability of petroleum fluids is the refining (or gas processing for gas), in which artificial chemicals are introduced in various forms (Islam, 2014, 2021). In order to render the process sustainable, there have to be fundamental changes to the refining process. Fig. 1.21 shows the overall picture of conventional refining and how it can be transformed. The economics of this transition is reflected in the fact that the profit made through conventional refining would be directly channeled into reduced cost of operation. This figure amounts to the depiction of a paradigm shift. The task of reverting to natural from unnatural has to be performed for each stage involved in the petroleum refining sector. A sustainable refinery can render the process sustainable and create enough incentive to investigate the concept of Downhole refinery (Islam, 2020). In our previous work, we have identified the following sources of toxicity in conventional petroleum refining: • Use of toxic catalyst. • Use of artificial heat (e.g., combustion, electrical, nuclear). The use of toxic catalysts contaminates the pathway irreversibly. These catalysts should be replaced by natural performance enhancers. In this proposed theme, research should be performed in order to introduce catalysts that are available in their natural state. This will make the process environmentally acceptable and will reduce the cost very significantly. The problem associated with efficiency is often covered up by citing local efficiency of a single component. When global efficiency is considered, artificial heating proves to be utterly inefficient. Recently, Khan and Islam (2016) have demonstrated that direct heating with solar energy (enhanced by a parabolic collector) can be very effective and environmentally sustainable. They achieved up to 75% of global efficiency as compared to some 15% efficiency when solar energy is used through electricity conversion. They also discovered that the temperature generated by the solar collector can be quite high, even for cold countries. Note that the direct solar heating or wind energy does not involve the conversion into electricity that would otherwise introduce toxic battery cells and would also make the overall process very low in efficiency. In order to introduce total zero-waste scheme, a green supply chain framework is introduced to achieve sustainability in refining operations. The specific aspects of the model are as follows: 1. Zero emissions (air, soil, water, solid waste, hazardous waste). 2. Zero waste of resources (energy, materials, human). 3. Zero waste in activities (administration, production).

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FIGURE 1.21

1. Introduction

Natural chemicals can turn a sustainable process into a sustainable process while preserving

similar efficiency.

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FIGURE 1.22 Unconventional reserve growth can be given a boost with scientific characterization.

FIGURE 1.23 Profitability grows continuously with time when zero-waste oil recovery scheme is introduced.

4. Zero use of toxics (processes and products). 5. Zero waste in product life cycle (transportation, use, end of life). We have seen the scientific analysis that gives an optimistic picture of the reserve development. By properly characterizing reservoirs and using technologies that best suit the broader sustainability picture, one can make the reserve grow continuously (Fig. 1.22). This picture can be further enhanced by using zero-waste scheme at every stage of EOR operations. This can be further bolstered by using petroleum products in different applications, based on their long-term impact. This concept has been tested by Islam et al. (2018).

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Consider the use of zero-waste engineering, which is the only truly sustainable oil recovery technique. Fig. 1.23 shows how enhanced oil recovery adds to the profitability over conventional primary recovery processes. Enhanced oil recovery schemes are well established and use either added chemicals or energy (e.g., steam) to increase profitability. This profitability goes up tremendously if zero-waste schemes are added. Zero-waste represents the use of waste products from the petroleum operation and other naturally available materials that are abundant in the locality of the petroleum operation site. In summary, sustainable production ensures exponential economic growth. Such production tactics when coupled with sustainable economic models offer a true paradigm shift in all aspects of economic development. Based on the discussion presented in this section, the following conclusions can be reached. 1. Total sustainability has eluded petroleum operators due to myopic vision of profit maximization in the short term. A long-term approach involves environmental considerations before profit making. 2. EOR is an integral part of petroleum operations and a sustainable approach involves considering zero-waste approach in all aspects, including refining, drilling, and production. Most importantly, however, rendering refinery zero-waste can help sustain the EOR process, due to optimization of the energy and mass cycle. 3. Series of novel zero-waste technologies are introduced in order to demonstrate how steps can be taken to keep the EOR totally sustainable. 4. Sustainable processes show very high global efficiency. 5. By minimizing processing with artificial chemicals, great strides are made toward achieving both environmental and economic sustainability.

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C H A P T E R

2 Petroleum in the big picture 2.1 World energy Human civilization is synonymous with carbon-based fuel. The use of fossil fuels for energy began at the onset of the industrial revolution. In the beginning, coal was the fuel of choice. Shortly, before the introduction of oil and gas as the fossil fuel of convenience, scarcity of coal in the coming decades was drummed up (Zatzman, 2012). In this, coal offered a peculiar distinction. As pointed out by Clark and Jacks (2007), despite enormous increases in output, the coal industry was credited with little of the national productivity advance either directly or indirectly through linkages to steam power, metallurgy, or railways. The “cliometric” account of coal in the industrial revolution is represented in Fig. 2.1. The horizontal axis shows cumulative output since the beginning of extraction in the northeast coalfield, and the vertical axis shows a hypothetical real cost of extraction per ton, which rises slowly as total extraction increases. However, real extraction costs are only moderately higher at the cumulative output of the 1860s than at cumulative output of the 1700s. In this portrayal, the supply of coal is elastic. When demand increased so, did output, with little increase in price at the pithead. But the same expansion of output could have occurred earlier or later had demand conditions been appropriate. The movement outward in the rate of extraction was caused by the growth in population and incomes, and by improvements in transport and reductions in taxes, which reduced the wedge between pithead prices and prices to the final consumers. Although the alarm that the world would run out of coal was sounded over 100 years ago, this has not been the case. It is true all around the world, but particularly meaningful in the United States, which achieved energy independence only in recent years. In 1975, the US Geological Survey (USGS) published the most comprehensive national assessment of US coal resources, which indicated that as of January 1, 1974, coal resources in the United States totaled 4 trillion short tons. Although the USGS has conducted more recent regional assessments of US coal resources, a new national-level assessment of US coal resources has not been conducted. The best estimates are published by the US Energy Information Administration (EIA) that publishes three measures of how much coal is left in the United States. The measures are based on various degrees of geologic certainty and on the economic feasibility of mining the coal.

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12 1860s

Cost of Extraction (s./ton)

10

8 1700s

FIGURE 2.1 The cliometric account of the coal industry in the industrial revolution. Source: From Clark and Jacks (2007). Coal and the Industrial Revolution, 1700
1869, European Review of Economic History, 11, 39
72.

6

4

2

0 0

200

400 600 Cumulative Output (m. tons)

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EIA’s estimates for the amount of coal reserves as of January 1, 2020, by type of reserve, are as follows: 1. Demonstrated reserve base (DRB) is the sum of coal in both measured and indicated resource categories of reliability. The DRB represents 100% of the in-place coal that could be mined commercially at a given time. EIA estimates the DRB at about 473 billion short tons, of which about 69% is underground mineable coal. 2. Estimated recoverable reserves include only the coal that can be mined with today’s mining technology after considering accessibility constraints and recovery factors. EIA estimates US recoverable coal reserves at about 252 billion short tons, of which about 58% is underground mineable coal. 3. Recoverable reserves at producing mines are the amount of recoverable reserves that coal mining companies report to EIA for their US coal mines that produced more than 25,000 short tons of coal in a year. EIA estimates these reserves at about 14 billion short tons of recoverable reserves, of which 60% is surface mineable coal. Fig. 2.2 shows the US coal reserve in 2019. Based on US coal production in 2019, of about 0.706 billion short tons, the recoverable coal reserves would last about 357 years, and recoverable reserves at producing mines would last about 20 years. The actual number of years that those reserves will last depends on changes in production and reserves estimates. Six states had 77% of the DRB of coal as of January 1, 2020: 1. 2. 3. 4.

Montana: 25% Illinois: 22% Wyoming: 12% West Virginia: 6%

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FIGURE 2.2 US coal reserve. Source: From EIA, 2020. Rankings about energy in the World, International—U.S. Energy Information Administration (EIA). https://www.eia.gov/international/overview/world#.YhONEDkZEkA.

5. Kentucky: 6% 6. Pennsylvania: 5% Twenty-five other states had the remaining 23% of the DRB (Fig. 2.3). In terms of world reserves, as of December 31, 2016, EIA estimates of total world proved recoverable reserves of coal were about 1144 billion short tons (or about 1.14 trillion short tons), and five countries had about 75% of the world’s proved coal reserves. The top 10 countries and their share of world proved coal reserves as of 12/31/2016 (Table 2.1) (Fig. 2.4).

2.2 Energy in 2020: the year of COVID The pandemic led to huge economic losses. Global GDP is estimated to have fallen by over 3.5% in 2020—the largest peacetime recession since the great depression. The International Monetary Fund (IMF) estimates that around 100 million people have been pushed into poverty as a result of the virus. And the economic scarring from the pandemic—especially for the world’s poorest and least-developed economies—is expected to

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FIGURE 2.3 Coal resources in the United States. TABLE 2.1 Coal reserve in top 10 countries. #

Country

Coal reserves (tons) in 2016

World share

1

United States

254,197,000,000

22.3%

2

Russia

176,770,840,800

15.5%

3

Australia

159,634,329,600

14.0%

4

China

149,818,259,000

13.1%

5

India

107,726,551,700

9.5%

6

Germany

39,802,209,480

3.5%

7

Ukraine

37,891,906,250

3.3%

8

South Africa

35,053,458,000

3.1%

9

Poland

28,451,723,410

2.5%

10

Kazakhstan

28,224,647,550

2.5%

persist for many years after the virus is brought under control. Long COVID can take many different forms and there is always the possibility that new viruses will emerge with similar consequences (Islam et al., 2022).

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FIGURE 2.4 Global coal production history.

The impact of COVID-19 and the oil prices war are proving to be a two-pronged crisis for oil, gas, and chemicals companies. Oil prices dropped, reaching even negative territories, due to failed agreements on production cuts and the need for chemicals and refined products is slowing from industrial slowdowns and travel restrictions in the wake of this global pandemic. According to BP economists, global oil demand is estimated to have declined in 2020 by an unprecedented 9.3%, or 9.1 million b/d. The decline was far bigger than expected based on past relationships and the extent of that discrepancy was far greater than for any of the other demand components. The shortfall in natural gas, meanwhile, was in line with the model predictions, whereas electricity consumption actually fell by less than predicted (BP, 2021). In comparison to oil consumption, natural gas use in 2020 showed far greater resilience. Global gas demand fell in 2020 by 2.3%, or 81 billion cubic meters (bcm), a similar decline to that seen in 2009 in the aftermath of the financial crisis. Gas consumption was down in most regions, except for China, where demand grew by almost 7% over 2019. In the pandemic year, 2020, the world has been bombarded with daily headlines of unprecedented developments and volatility. Today’s energy price is sharply affected by such rhetoric and political theatrics (Islam et al., 2018). In a way, the global pandemic was the “mother of all stress tests”1. While fossil fuel, in particular natural gas, showed resiliency, so-called renewables continued to surge. Recent BP report (BP, 2021) revealed a global energy market that transformed in 2020 unlike any year in history. Primary energy and carbon emissions fell at their fastest rates in more than 75 years, with global energy demand estimated to have fallen by 4.5% in 2020. Fig. 2.1 shows energy consumption in the past and its projection in the future (Fig. 2.5). This collapse in oil demand, caused by lockdown impositions of the pandemic, marked the largest recession since the end of World War II. Meanwhile wind and solar capacity 1

A term used by BP’s Chief Economist, quoted by Davis (2021).

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FIGURE 2.5 Energy consumption in 2020 and beyond.

FIGURE 2.6 Share of primary energy consumption by source, world (EIA, 2021a).

increased by a colossal 238 GW in 2020—50% larger than any previous expansion. Similarly, the share of wind and solar generation in the global power mix recorded its largest ever increase. This gain (Fig. 2.6) was later engrained in US policy after the election of Joe Biden as the president, who made it a campaign promise to phase out fossil fuel. These policies have created an economic crisis, not seen in many decades. These policies are based on the premises: carbon is our enemy and the world needs to end its dependence on fossil fuels as quickly as possible. No other discipline than the energy sector has suffered more from this inherently fallacious cognition pattern. Even though petroleum continues to be the world’s most diverse, efficient, and abundant energy source, due to “grim climate concerns,” global initiatives are pointing toward a “go green” mantra. When it comes to defining “green,” numerous schemes are being presented as “green” even though all it means is the source of energy is not carbon. In fact, the “left,” often

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emboldened with “scientific evidence,” blames carbon for everything, “forgetting” that carbon is the most essential component of plants—the essence of the ecosystem. The “right,” on the other hand, denies climate change altogether, stating that it is all part of the natural cycle and there is nothing unusual about the current surge in CO2 in the atmosphere. Both sides ignore the real science behind the process. In this, both “left” and “right” fail to recognize the fact that artificial chemicals added during practically all industrial processes make the atmosphere all toxic. Tennessee—a state Al Gore once represented—the world started to believe carbon was the enemy. This drumbeat against petroleum continued even during the Bush 43 era and President George W. Bush talked about “oil addiction” (Islam et al., 2010). Even his most ardent detractors embrace that comment as some sign of deep thinking. Then came the Obama era—the era of contradictions and paradoxes (Brown and Epstein, 2014). The Trump era is marked with an unprecedented surge in oil and gas production activities that catapulted the United States to energy solvency (Islam, 2020). The growth started in the Obama era but in a paradoxical move, Obama increased investments in so-called renewable projects, painting the US administration as environmentally friendly, with the fundamental premise that oil is not sustainable but renewable energies, such as solar, wind, and biofuel, are. Global Market Insights Inc. has published a new report on “Oil & Gas Infrastructure Market” that provides in-depth analysis and statistics of the industry segments. The report forecasts the market size for oil & gas infrastructure will surpass USD 1115 Bn by 2030, growing at around 6% compound annual growth rate from 2022 to 2030. North America oil and gas infrastructure market is predicted to observe a 6.5% growth rate till 2030. The investment toward the expansion of pipeline network and terminals together with the ongoing deployment of new refinery focusing on the natural gas liquids (NGL), liquefied petroleum gas, and other petroleum products will provide a favorable opportunity for the market expansion. Oil and gas storage market size valued at nearly USD 22 billion in 2021. High dependability of resources for power generation coupled with the retirement of coal-fired power substations will complement the segment statistics. Oil, gas, and NGL pipeline market is anticipated to surge at a rate of 6% through 2030. Paradigm shift toward gas-based power plants and surging necessity for propylene, ethylene, and other NGL will drive the investment toward the improvement of the infrastructure. Upon the election of President Donald Trump, the propaganda against fossil fuels reached an unprecedented hype, only to be eclipsed with COVID-19 hysteria (Islam et al., 2022). What Al-Gore called “extra chromosome right wing” (to define Reagan voters) and Hillary Clinton called “basket of deplorables” (to define Trump supporters) became the buzzword to hurl insult at anyone who does not subscribe to the mainstream narrative of “climate change.” For them, anyone advancing any argument against the so-called “97% consensus” is immediately identified as a suspect and climate change denier, and, therefore is worthy of being intellectually lynched by categorizing him/her as a Trump supporting, MAGA (Biden calls them ultra-MAGA extremist) hat-wearing hillbilly. At this point, anything the “scientist” would say, no matter how egregious, be it manufacturing cow-free burgers and milk or dimming the sun with toxic chemicals, would pass for “science” while anyone advancing “alternate” explanation would be ridiculed. This is not

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a scholarly forum, where real science can survive (Kraychik, 2019). Islam and Khan (2019) called out the lunacy of the anticarbon hysteria. The readership was reminded that it is New Science that has made the following roller coaster transition in the past and is poised to continue along the same path, as follows: In the 70s, there was this coming of second ice age. In the 80s, acid rain was considered the villain that was ruining the planet earth. In the 90s, global warming was said to bring the earth at the brink of the tipping point. In the 2000s, climate change (different from global warming) was declared real and carbon was designated the enemy. 5. In the 2010s, engineering the earth began, and the natural ecosystem, carbon, water, and sunlight were designated the enemy. 6. In 2019, we prepare for the 2020s, in which an apology to acid rain is being offered and the plans are underway with billions of dollars of funding to “dim” the sun with acid and let the entire world wear toxic sunglasses—all funded by universal carbon taxes. 7. In 2021, as COVID-19 pandemic heaped corporate profits to an obscene state, climate change hysteria makes a comeback. 1. 2. 3. 4.

The relative immunity of natural gas was helped by sharp falls in gas prices, which allowed gas generation to gain a share in the US power market and hold its own in the European Union (EU). In Central Europe, imports fell by more than 8% year/year in 2020. The gas-on-gas competition in Europe takes the form of pipeline imports—predominantly from Russia—competing against liquefied natural gas (LNG) imports—largely from the United States as the marginal source of LNG. As LNG imports have increased in recent years, it has raised the question of the extent to which Russia and other pipeline gas exporters will compete against LNG to maintain their market share or instead forgo some of that share to avoid driving prices too low. This issue could become more acute in a transition in which Europe moves away from natural gas and competition between different gas supplies intensifies. Prior to the Russian invasion of Ukraine in February, 2022, Russian exporters were prepared to forgo some market share. Pipeline imports from Russia as a share of European gas demand fell from 35% in 2019 to 31% in 2020, with much of the reduction happening in the first half of last year. Some of the decline in pipeline imports initially reflected the record storage levels that had built up toward the end of 2019. In contrast, LNG imports were up year/year in the first half of 2020, and their share of European demand for the year as a whole was broadly unchanged at 21% (Tollefson, 2022). After COVID-19 pandemic, Russia’s invasion of Ukraine became the most significant energy-related event. Only 2 days before Russian invasion, on February 22, 2022. Germany scuttled its approval of a newly built gas pipeline from Russia, and since invasion is planning to import LNG from countries such as Qatar and the United States. Belgium is reconsidering its exit from nuclear power, while Italy, the Netherlands, and the United Kingdom are all accelerating efforts to install wind power. Fertilizer plants across Europe have announced they will scale back production, and 31 countries around the world have agreed to release oil from their strategic reserves. Russia’s unprovoked invasion of Ukraine roiled the markets and geopolitics of energy, driving oil and gas prices to their highest levels in nearly a decade and forcing many countries to reconsider their energy

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supplies. According to the International Energy Agency, Russia is the world’s largest oil exporter to global markets, and its natural gas fuels the European economy. The United States, the EU, and others have imposed economic sanctions on Russia and have announced plans to wean themselves off that country’s fossil fuels. However, Russian oil and gas continue to flow. Fig. 2.7 shows the dependence of various countries on Russian natural gas. Data from the EU Agency for the Cooperation of Energy Regulators shows which countries’ energy supply would be most at risk in the case of a Russian gas freeze or an embargo. Among Europe’s major economies, Germany imports around half of its gas from Russia, while France only obtains a quarter of its supply from the country, according to the latest available data. The biggest source of French gas was Norway, supplying 35%. Italy would also be among the most impacted at a 46% reliance on Russian gas. The United Kingdom draws half of its gas supply from domestic sources and imports mostly from Norway and also Qatar. Spain is also not on the list of Russia’s major customers, the biggest trade partners of the country being Algeria and the United States. Some smaller European countries rely exclusively on Russian gas, namely, North Macedonia, Bosnia and Herzegovina, and Moldova. Dependence also was above 90% of gas supply in Finland and Latvia and at 89% in Serbia, as per the latest available data. Low dependence could be seen in the Netherlands, Romania, and almost no dependence on Russian gas exists in Georgia, Ireland, and Ukraine. However, the latter country has been buying natural gas from the EU since 2015 after a previous armed conflict with Russia over Crimea. This means it could be subject to the reimport of Russian gas via the bloc. FIGURE 2.7 Dependence of selected countries on Russian gas. Source: From Statista, 2022. https://www.statista.com/chart/ 26768/dependence-on-russian-gas-by-europeancountry/.

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The EU imported around 40% of its natural gas, more than one-quarter of its oil and about half of its coal from Russia in 2019. And despite bold promises about cutting ties with Russia, European nations have thus far opted for easy energy: the amount of Russian oil and gas entering Europe has actually increased since the war in Ukraine began. Europe sent Russia around h22 billion (US$24 billion) for oil and gas in March alone, according to Bruegel, a think tank based in Brussels. But that could change in the coming months, as countries implement plans to diversify their energy sources and reduce the flow of Russian oil and gas. Poland, for example, has announced it will ban all imports of Russian oil, gas, and coal by the end of this year, and Germany and Austria are laying the groundwork for rationing natural gas. The European Commission has released plans to curb imports of Russian gas by around two-thirds by the end of the year. That strategy relies largely on increasing imports of natural gas from abroad and is it not clear whether individual nations in Europe will follow this plan. On 25 March, US President Joe Biden pledged to send more LNG to Europe, and Germany has already signed a deal to import the product from Qatar. European officials have also been in talks with Japan and South Korea about redirecting LNG that would otherwise go to those two countries. The commission’s plan seeks to replace 101.5 bcm of Russian gas by the end of the year. Boosting imports to Europe from other countries could account for nearly 60% of that reduction, and another 33% would come from new renewable-energy generation and conservation measures, the plan suggests. The energy crisis is particularly acute in Germany, which relies on Russia for roughly half of its natural gas and coal and for more than one-third of its oil. Germany’s immediate challenge is to reduce reliance on natural gas in the power-generation sector, which is further complicated by the country’s exit from nuclear power: its last three nuclear stations are scheduled to close down this year. A report last month by Leopoldina, the German National Academy of Sciences, found that Germany could survive the next winter without Russian energy (Tollefson, 2022), but only with extreme efforts to replace Russian gas with imports while ramping up coal-fired power plants and promoting large-scale conservation and energy efficiency. It also depends on higher prices causing a slowdown in heavy industry in the country. The energy picture is less clear at the global level. When prices for oil and gas have surged in the past, it has spurred a series of changes in opposite directions: consumers tended to drive vehicles less and purchase more fuel-efficient versions, whereas companies and nations invested in oil and gas infrastructure around the globe to ramp up production. This aspect is discussed in the latter sections. Curiously, the sanctions on Russia that were supposed to cripple the Russian economy did the opposite. The oil prices skyrocketed and Russian ruble became much stronger than the prewar level and beyond (Karaian, 2022). The ruble cemented its totally unpredicted status as the world’s best-performing currency, rising to new multiyear highs this week. Fig. 2.8 shows gold price has risen steadily in ruble, in line inflation rate. The fluctuations are contained within months, if not days. Even during Ukraine invasion, when western bloc imposed sanctions on Russia, the price rose sharply but came back to prewar level within short months. Fig. 2.9 shows the history of gold price in US dollars. Fluctuations in this graph are long lived and overall there are signs of instability.

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FIGURE 2.8 History of gold prices in Russian ruble.

FIGURE 2.9 History of gold prices in US dollar.

In June, Ruble traded at its strongest level against the US dollar since June 2015. It has gained about 35% so far in year 2022, beating every major currency, and has more than doubled from its postinvasion low.

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Although Russia’s economy has held up better than many expected, the outlook is gloomy, with double-digit inflation and most economists predicting a deep recession. But capital controls imposed by its central bank, including those that forced exporters to exchange some of their earnings into rubles, have increased demand for the Russian currency. Higher earnings from oil and gas exports, which have surged as prices rise and demand in Asia makes up for cutbacks in Europe, have kept the ruble elevated. At the same time, Russian imports have fallen sharply, partly the result of many foreign companies pulling out of Russia, which also support the ruble. In late February, after the invasion, the ruble crashed to its weakest-ever level against the dollar, and Russia’s central bank more than doubled interest rates, to 20%, as part of its moves to stop the outflow of rubles from the economy. Since then, some restrictions have been loosened and rates have been cut back to 9.5%, where they were set before the invasion. But the ruble continues to strengthen, which helps ease inflation but also puts pressure on Russia’s budget, which relies on energy sales that are often denominated in dollars.

2.3 New world order The existence of the new world order itself has been questioned as a conspiracy theory. However, this phrase has been recognized at all levels of governance, The recent Congress-sanctioned report in the United States (U.S. Global Change Research Program, 2017) made it clear that we cannot have good environment and good economy at the same time. Only recently, the general public has started to question the establishment narrative. Although the mistrust has often been marginalized as a “conspiracy theory,” there is a need to address the incessant disinformation that comes to light. For energy pricing, which is a function of economics, politics, as well natural resources, to be sound, it is important to understand the science behind energy pricing. In this paper, the role of new world order—a well known doctrine of globalization—on energy pricing is scrutinized from a purely scientific perspective. Presented herewith past and ongoing discussions and international initiatives, deliberations of the Club of Rome, Sarkozy Commission, UN Friends of the Chair Group, Global Monitoring Reports, UN Human Development Index, Happy Planet Index, etc., and show how energy prices are manipulated to gain more control in order to enhance the agenda of one world governance. The extreme nature of today’s world economy is manifest in the Oxfam report that showed that in 2020, 2153 billionaires had more wealth than the 4.6 billion people who make up 60% of the planet’s population. In the post-COVID era, the Oxfam (2022) headline reads as follows: 10 richest men double their fortunes in pandemic while the incomes of 99% of humanity fall. There is little doubt that the global community is headed in the wrong direction. In order to rescue the world from the impending crisis, World Economic Forum, partnered with United Nations and all her affiliates have sponsored numerous initiatives, summed up in Agenda 21. Agenda 21 “sets out a plan of action to guarantee that life in the next millennium will change substantially for the better.” It was endorsed by the world’s governments at the UN Conference on Environment and Development, in

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Rio de Janeiro, 5 years ago, in June 1992. Agenda 21 is rooted in Club of Rome founded in 1968 by David Rockefeller among others. Soon after its formation, a group of scientists published the results of their “Limits to Growth” simulated model of world population, environment, and economics, predicting an impending collapse of civilization on the weight of human population that would invariably lead to environmental and economic collapse. This was entirely based on the Malthusian theory that has been recently characterized as “phenomenal” by Islam et al. (2018). They argued that Agenda 21 and its derivatives are fueled by a sinister plot to control the world to amass obscene amount of wealth. Islam et al. (2018) also predicted that with this globalization plan, the world will experience extreme inequality and socioeconomic collapse, the type the world is experiencing at present. Agenda 21 is motivated by World governance (Thore and Tarverdyan, 2022). The term world governance is broadly used to designate all regulations intended for organization and centralization of human societies on a global scale. The Forum for a new World Governance defines world governance simply as “collective management of the planet.” This initiative is neither new, nor is it well intended. On February 17, 1950, James P. Warburg announced in front of the Senate Subcommittee of the Committee on Foreign Relations of the United States Senate. “We shall have world government, whether or not we like it. The question is only whether world government will be achieved by consent or by conquest.” All Abrahamic religions also talk about a World Order, but none involves “conquest.” James Warburg was no prophet, nor was he a politician or elected official. He (August 18, 1896
June 3, 1969) was a German-born American banker. He was the “prophet” of the Money god. He was the financial adviser to Franklin D. Roosevelt. His father was banker Paul Warburg, member of the Warburg family and “father” of the Federal Reserve system. After World War II, Warburg helped organize the Society for the Prevention of World War III in support of the Morgenthau Plan. The plot to change the world with the phenomenal model had just began. The scheme of federal reserve, the entire UN fiasco, and economic extremism in name of preventing global catastrophe would follow. The world would travel the path to globalization through the works of David Rockefeller, Sr (June 12, 1915
March 20, 2017), a notorious American banker, statesman, globalist, and a grandson of oil tycoon John D. Rockefeller, who in turn would control each and every US president, UK Prime Minister, and any leader worth a mention. In 2007, Zatzman and Islam identified what they called HSSA (Honey - Sugar Saccharine - Aspartame) degradation. It involves continuous degradation in the paradigm of economic development. This process of spiraling down degradation from total sustainability to total implosiveness with the transition from gold standard to bitcoin. In the post-Renaissance allegorical transition, HSSAN (Honey - Sugar - Saccharine Aspartame - Nothing) symbolizes degradation from honey (a real source with real process) to nothing via aspartame (with both source and pathway that are highly artificial). This transition has been the hallmark of environmental degradation that has been fueled by equally toxic profiteering through standards that dropped from Gold - Coin - Paper - Bitcoin - Nothing, thus causing black hole-like degradation in global geopolitics. Sustainability can be restored only if this trend is reversed from artificial to real. This state of the US politics was captured by President Donald Trump during the entire presidential campaign as well as by Senator Bernie Sanders (who started the theme “the system is corrupt” citing corruption in financial establishment, political establishment, and

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corporate media establishment) and has motivated millions of Americans in losing trust in the political system as along with the mainstream media (Islam, 2018). There is little doubt that Trump was correct in asserting that US corruption has polluted the entire world and must be stopped at its track (Chayes, 2017). The beneficiary of these corrupt operations are mainly the military
industrial complex (Cohen, 2015; Byrne, 2017) and the Big Pharma (Islam et al., 2015). The energy sector, particularly the natural resource-based one is used as the escape goat that has little control over energy prices (Zatzman, 2012). Energy pricing is manipulated by the same group that controls all facets of current civilization and is the source if all economic and political instabilities (Wallace, 2022). This question of new world order governing energy pricing has resurfaced after Russian invasion of Ukraine in February, 2022. Recently, Russia expressed readiness to develop a new global reserve currency alongside China and other BRICS2 nations, in a potential challenge to the dominance of the US dollar. President Vladimir Putin signaled the new reserve currency would be based on a basket of currencies from the group’s members: Brazil, Russia, India, China, and South Africa. The dollar has long been seen as the world’s reserve currency, but its dominance in share of international currency reserves is waning. Central banks are looking to diversify their holdings into currencies like the Yuan, as well as into nontraditional areas like the Swedish krona and the South Korean won, according to the IMF. Russia’s move comes after Western sanctions imposed over the Ukraine war all but cut the country out of the global financial system, curtailing access to its dollars and putting pressure on its economy. Those sanctions have likely encouraged Moscow and Beijing to work on an alternative to the IMF’s international reserve asset, the special drawing rights, Turner suggested. One possibility is that the BRICS basket currency could attract the reserves not just of the group’s members, but also countries already in their range of influence, he suggested. These include nations in South Asia and the Middle East. Russia has seen its currency the ruble rebound to above its prewar level, thanks to central bank support, after it plunged 70% in less than two weeks after the Ukraine invasion. It has risen 15.2% in June to 1.87 cents. Meanwhile, the Yuan has held steady at around $0.15 over the same period. On the consumer side, growing gaps between the richest and poorest people in many countries are changing patterns of car buying. Although consumption is likely to drop in the short term as drivers respond to rising prices, that does not mean we should expect a massive shift toward smaller or electric vehicles (EVs). That is because the people who tend to buy new vehicles are wealthier than they were in decades past, meaning they will not react to the economic pressure of higher petrol prices as much as before. By contrast, economists have yet to see major oil and gas companies ramp up their investments in fossil-fuel production. Global leaders have been emphasizing the need for decarbonization in the past few years, and companies are now more wary of sinking their own capital into assets that could be stranded as climate policies are ratcheted up in the future. 2

BRICS is the acronym coined to associate five major emerging economies: the Federative Republic of Brazil, the Russian Federation, the Republic of India, the People’s Republic of China, and the Republic of South Africa.

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Another key question is how rising energy prices and the potential loss of grain supplies from Ukraine and Russia could reinforce inflationary effects and drive up prices for food and other commodities. In the short term, prices have increased owing to hoarding and bidding wars. But global food stocks are sufficient to cover the loss of wheat and other grains from Ukraine as a result of the war itself, and losses from Russia owing to economic sanctions, says Christopher Barrett, an economist at Cornell University in Ithaca, New York. There could be disruptions to fertilizer markets because fossil fuels are a major feedstock, but Barrett says farmers around the world should be able to negotiate these changes by using substitutes (Tollefson, 2022). As to whether that signals the future behavior of Russia’s pipeline exports, though, is less clear. The decline in European gas demand is expected to be relatively short-lived, but may be entirely rational for pipeline exporters to use their flexibility to reduce supply temporarily to help stabilize the market and support prices. One factor affecting the pipeline exports in 2020 was a perception of how low European prices would need to fall to shut in LNG exports. Until 2020, the question was mostly hypothetical about what gas price it would take to shut in LNG exports. European LNG forward prices fell below operating costs, which triggered a significant shut-in of US LNG exports. Average utilization rates of US LNG facilities began to fall in April last year, reaching a low of around 30%
35% at the height of the summer. Still, lower 49 LNG exports increased by around 30% last year, as additional trains came onstream. However, had it not been for the canceling of cargoes, the growth in US exports would have been closer to 80% (Tollefson, 2022). During the pandemic period, US renewables market scored, with the domestic power mix now rivaling coal at nearly 20%. Solar generation grew the most, up 24%, with wind 14% higher. Declines in gas demand were led by Russia, down 33 bcm, and in the United States, with consumption down 17 bcm, according to BP. In contrast, China gas consumption rose 22 bcm, while Iran’s demand was up10 bcm. This is the much-dreaded environmental scheme propped up by institutions such as the United Nations. Yet, the science that others have been working with have no avenue to evaluate, let alone critique, the only “scientific” recourse being promoted. It is as if the world has gone insane and cannot fathom fundamental the questions as to what is wrong with carbon, water, or sunlight. The nuclear industry is on life support in most countries, so the future appears to lie mostly with solar and wind power. Chhetri and Islam (2008) deconstructed the “renewable” energy myth and showed that the processed that are being peddled as “green” are in fact more environment hostile than fossil fuels. However, most energy experts do not dispute the veracity of the “go green” mantra and rely on another argument. Wind power is one of the cleanest forms of energy, with a carbon footprint 99% lower than coal and 75% less than solar, according to a study by Bernstein Research, a US-based research, and brokerage firm. These numbers are misleading and outright misinformation. Chhetri and Islam (2008) discuss the role of global efficiency in determining true efficiency and footprint. For instance, these numbers change drastically if one includes the total energy circuit and long-term sustainability.

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In peddling renewables, authorities posit the following questions: can we transition to these renewable energy sources and continue using energy the way we do today? And can we maintain our growth-based consumer economy? Even these wrong-headed questions lead to the fact that fossil fuel is not replaceable, not the least with so-called renewable energy. The electricity sector. The logic used is as follows: solar and wind produce electricity, and the fuel is free. This is a falsehood. There is nothing free or “green” about those turbines, solar panels, and energy-storing batteries. For instance, there are four main types of battery technologies that pair with solar energy systems: 1. Lead-acid batteries. There are two main types of lead acid batteries: flooded lead acid batteries and sealed lead acid batteries. Flooded lead-acid batteries require ventilation and regular maintenance to operate correctly, which increases the chances of the battery leaking. 2. Lithium-ion batteries. As the popularity of EV began to rise, EV manufacturers realized lithium ion’s potential as an energy storage solution. They quickly became one of the most widely used solar battery banks. They are more expensive than other energy storage technologies. Also, because of their chemistry, lithium-ion storage systems have a higher chance of catching fire due to the thermal runaway3 effect. However, if installed properly, the chance of your battery catching fire is close to zero. 3. Nickel-based batteries. Ni-Cd batteries are a favorite in the aircraft industry. Cd is extremely toxic. 4. Flow batteries. Flow batteries are an emerging technology in the energy storage sector. They contain a water-based electrolyte liquid that flows between two separate chambers within the battery. When charged, chemical reactions occur which allow the energy to be stored and subsequently discharged. Their larger size makes them more expensive than the other battery types. The high price, combined with the large size, makes it hard to adapt them to residential use. Reuters (Neslen, 2021) revealed important data regarding wind energy. Europe is the world’s second-largest producer of wind-generated electricity, making up about 30% of the global capacity, compared to China’s 39% (Neslen, 2021). Wind Europe, a Brusselsbased trade association, which promotes the use of wind power in Europe, expects 52,000 blades a year to need disposal by 2030, up from about 1000 today. The EU’s share of electricity from wind power has grown from less than 1% in 2000, when the continent began to curb planet-heating fossil fuels, to more than 16% in 2021. Immediately, the problem of environmental catastrophe arises as tens of thousands of blades are being stacked and buried in landfill sites where they will take centuries to decompose and literally never assimilate with nature. Spanish turbine maker Siemens Gamesa launched the first recyclable blades, which use a technology that allows their carbon and glass fibers to be reused in products like screen monitors or car parts. This, however, does nothing to the ecosystem that is permanently damaged (Chhetri and Islam).

3

Thermal runaway describes a process that is accelerated by increased temperature, in turn releasing energy that further increases temperature.

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In addition to all the above points, intermittency (the sun does not always shine, the wind does not always blow) still poses barriers to high levels of solar-wind electricity market share. Grid managers can easily integrate small variable inputs; but eventually storage, capacity redundancy, and major grid overhauls will be necessary to balance inputs with loads as higher proportions of electricity come from uncontrollable sources. All of this will be expensive—increasingly so as solar-wind market penetration levels exceed roughly 60%. Some of the problems associated with integrating variable renewables into the grid are being worked out overtime. But even if all these problems are eventually resolved, only about one-fifth of all final energy is consumed in the form of electricity. The transport sector: EVs cars are becoming more common and are being promoted as “green.” With EV sales expected to surge, global battery demand could increase over fivefold between 2020 and 2025, according to S&P Global Market Intelligence data. EVs require roughly six times more minerals than cars with internal combustion engines (ICEs). That means EV makers will feature an increasing share of the world’s lithium, cobalt, nickel, and other metals needed to make batteries. Already, the proportion of these metals dedicated to the EV market is growing, threatening to trigger a shortage. Passenger plug-in EVs will be responsible for an estimated 68.2% of global lithium demand and 39.3% of cobalt demand by 2025. Approximately 12.8% of primary nickel demand will come from passenger EV makers by 2025 (Erickson, 2021) (Fig. 2.10). Market intelligence analysts forecast a lithium and cobalt shortage surfacing by 2025. Primary nickel is expected to fall into a deficit in 2021. In addition, volatile costs, sustainability concerns, and a lack of new mine growth for nickel have some automakers worried. Lithium demand could increase by more than 40 times in the next two decades, while graphite, cobalt, and nickel demand could climb by 20
25 times, if the world meets the climate targets set by the Paris Agreement on climate change, according to the International Energy Agency. This process undermines the damages done by the renewables. Yet, “The evolution of battery chemistry is the biggest unknown in many ways,” is a statement made by Chris Berry, an independent battery metals analyst and president of House Mountain Partners. Nickel-containing batteries dominate the pure battery EV market. In 2020, nickel
manganese
cobalt batteries made up over 65% of the market because they offer higher energy density compared with batteries without nickel and are a good fit for larger EVs going longer distances. However, battery makers in South Korea and China have been developing a battery that uses more nickel and reduces demand for cobalt. Lithium demand would be relatively unaffected by the market’s preference for nickel-rich batteries, though demand for the white metal coming from EVs is expected to skyrocket, increasing as much as fourfold between 2020 and 2025, according to market intelligence (Fig. 2.11). The industrial sector. Making pig iron—the main ingredient in steel—requires blast furnaces. Making cement requires 100-meter-long kilns that operate at 1500 C. In principle, it is possible to produce high heat for these purposes with electricity or giant solar collectors, but nobody does it that way now because it would be much more expensive than burning coal or natural gas. Crucially, current manufacturing processes for building solar panels and wind turbines also depend upon high-temperature industrial processes fueled by oil, coal, and natural gas. Again, alternative ways of producing this heat are feasible in

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Passenger plug-in EVs to dominate global lithium, cobalt and nickel demand Passenger PEVs Share of global demand for metal metal demand (000 tonnes) (%)

Passenger PEV demand for metal (000 tonnes)

Metal

600

80 70

Lithium carbonate

Primary nickel Refined cobalt

60 500 50 400 40 300 30 200 20 100

Share of global metal demand (%)

700

10

0

0 2019

2020

2021*

2022*

2023*

2024*

2025*

Data compiled Sept. 16, 2021. Lithium and cobalt data as of Aug. 20, 2021. Nickel data as of Aug. 24, 2021. * Data reflected are forecasts. Plug-in electric vehicles, or PEVs, include baery electric vehicles and plug-in hybrid electric vehicles. Historical figures draw in part on the work of Internaonal Nickel Study Group and World Bureau of Metal Stascs. Source: S&P Global Market Intelligence

FIGURE 2.10 Impact of increased electric vehicle manufacturing. Source: Erickson, C., 2021. EV Impact: Battery Disruptors are Jolting Metal Supply Chains, S&P Global Intelligence. https://www.spglobal.com/marketintelligence/en/newsinsights/latest-news-headlines/ev-impact-battery-disruptors-are-jolting-metal-supply-chains-66518783.

principle—but the result would probably be significantly higher-cost solar and wind power. And there are no demonstration projects to show us just how easy or hard this would be. The food sector. Nitrogen fertilizer is currently produced cheaply from natural gas; it could be made using solar or wind-sourced electricity, but that would again entail higher costs, while polluting the environment even more (Islam and Khan, 2019). Food products—and the chemical inputs to farming—are currently transported long distances using oil, and farm machinery runs on refined petroleum. It would be possible to grow food without chemical inputs and to relocalize food systems, but this would require more farm labor and might result in higher-priced food. Consumers would need to eat more seasonally and reduce their consumption of exotic foods. From a historical perspective, the falls in energy demand and carbon emissions are dramatic. But from a forward-looking perspective, the rate of decline in carbon emissions observed in 2020 is similar to what the world needs to average each and every year for the

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Baeries with nickel will connue to dominate global EV markets NMC-based (nickel-manganese-cobalt) NCA (nickel-cobalt-aluminum)

LFP (lithium-iron-phosphate)

Share of baery EV cathode demand (%)

100 90 80 70 60 50 40 30 20 10 0 2020

2021

2022

2023

2024

2025

Data compiled Sept. 16, 2021. Demand data as of Aug. 20, 2021. NMC baeries include NMC111, NMC532, NMC622, NMC721, NMC811, NMC90 and NMCA cathodes. Source: S&P Global Market Intelligence

FIGURE 2.11 Share of battery electric vehicles worldwide.

next 30 years to be on track to meet the Paris climate goals. If carbon emissions declined at the same average rate as last year for the next 30 years, global carbon emissions would decline by around 85% by 2050. For those of you familiar with BP’s latest energy outlook, that is roughly mid-way between the Rapid and Net Zero scenarios, which are broadly consistent with maintaining global temperature rises well below 2 C and below 1.5 C respectively. The 2020 fall in carbon emissions was obviously driven by a huge loss in economic output and activity. A simple calculation comparing the fall in emissions with the decline in world output equates to an implied carbon price of almost $1400/per tonne, scarily high. The challenge is to reduce emissions without causing massive disruption and damage to everyday lives and livelihoods. The yellow bars in the energy demand growth chart use a similar modeling approach to derive predicted movements for each of the demand components. As you can see, the fall in oil consumption in 2020 was far bigger than expected based on past relationships. Furthermore, the extent of that discrepancy was far greater than for any of the other demand components. The decline in natural gas was pretty much bang in line with the model prediction and electricity consumption actually fell by less than predicted. Indeed, for those of you who

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like to think in statistical terms, the only statistically significant prediction errors were those for total energy demand and oil demand. And the surprise in total energy demand can be entirely explained by the greater-than-expected fall in oil demand. Of course, for all of us who experienced extended lockdowns last year, this is hardly surprising. The lockdowns detracted from oil demand in a completely different way to a normal economic downturn, crushing transport-related demand. Mobility metrics fell across the board. Use of jet fuel and kerosene is estimated to have plunged by 40% (3.2 Mb/d) as aviation across much of the world was grounded (Figs. 2.12 and 2.13). In 2020, COVID-19 pandemic played a significant role in shaping global energy outlook. Because of some degree of lockdown in every country, COVID-19 pandemic has caused more disruption to the energy sector than any other event in recent history. The 2020 IEA World Energy Outlook report (IEA, 2020) examined in detail the effects of the pandemic, and in particular, how it affects the prospects for rapid clean energy transitions. As shown in Fig. 2.14, IEA assessment is that global energy demand is set to drop by 5% in 2020, energy-related CO2 emissions by 7%, and energy investment by 18%. The impacts vary by fuel. The estimated falls of 8% in oil demand and 7% in coal use stand in sharp contrast to a slight rise in the contribution of renewables. The reduction in natural gas demand is around 3%, while global electricity demand looks set to be down by a relatively modest 2% for the year. The global COVID-19 lockdowns caused fossil carbon dioxide emissions to decline by an estimated 2.4 billion tonnes in 2020—a record drop according to researchers at Future Earth’s Global Carbon Project (EurekAlert, 2020). The fall is considerably larger than previous significant decreases—0.5 (in 1981 and 2009), 0.7 (1992), and 0.9 (1945) billion tonnes of CO2 (GtCO2). It means that in 2020, fossil CO2 emissions are predicted to be approximately 34 GtCO2, 7% lower than in 2019. Ironically, the release of 2020s Global Carbon Budget came just ahead of the fifth anniversary of the adoption of the UN Paris climate Agreement, which aims to reduce the emission of greenhouse gases (GHGs) to limit global warming. Cuts of around 1 to 2 GtCO2 are needed each year on

Growth in oil demand Annual change

15% 10% 5% 0% -5% -10% 1940

FIGURE 2.12

1950

1960

1970

1980

History of growth in oil demand.

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2010

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Energy demand growth in 2020 Annual change 0% -2% -4% -6% -8% -10% -12% Primary energy

Oil

Natural gas

Coal

Electicity

2020 Predicted

FIGURE 2.13 Special events of year 2020.

average between 2020 and 2030 to limit climate change in line with its goals. However, the Trump administration was not on board of the Agreement and relaxed many of the GHG emission regulations while achieving very desirable results. Not surprisingly, emissions from transport account for the largest share of the global decrease. Those from surface transport, such as car journeys, fell by approximately half at the peak of the COVID-19 lockdowns. By December 2020, emissions from road transport and aviation were still below their 2019 levels, by approximately 10% and 40%, respectively, due to continuing restrictions. Total CO2 emissions from human activities—from fossil CO2 and land-use change—are set to be around 39 GtCO2 in 2020. The emissions decrease is notably more pronounced in the United States (212%) and EU27 countries (211%), where COVID-19 restrictions accelerated previous reductions in emissions from coal use. It appears least pronounced in China (21.7%), where the effect of COVID-19 restrictions on emissions occurred on top of rising emissions. In addition, restrictions in China occurred early in the year and were more limited in their duration, giving the economy more time to recover. In the United Kingdom, which first introduced lockdown measures in March, emissions are projected to decrease by about 13%. The large decrease in UK emissions is due to the extensive lockdown restrictions and the second wave of the pandemic. In India, where fossil CO2 emissions are projected to decrease by about 9%, emissions were already lower than normal in late 2019 because of economic turmoil and strong hydropower generation, and the COVID-19 effect is potentially superimposed on this changing trend. Despite lower emissions in 2020, the level of CO2 in the atmosphere continues to grow—by about 2.5 parts per million (ppm) in 2020—and is projected to reach 412 ppm averaged over the year, 48% above preindustrial levels. Preliminary estimates based on fire emissions in deforestation areas indicate that emissions from deforestation and other land-use change for 2020 are similar to the previous decade, at around 6 GtCO2.

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Oil market in 2020 Oil demand and supply Change (from beginning to end of phase), Mb/d

Demand

20 10 0 -10 -20 -30

Global oil stocks Mbbls 9200 8800 8400 8000

Oil prices (Brent) $/bbl 80 60 40 20 0 Phase 1 (Dec ‘19 – April)

Phase 2 (April – Aug)

Source: EIA (demand), IEA (supply), S&P Global Platts (prices). FIGURE 2.14

Supply and demand in 2020 (EurekAlert, 2020).

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Approximately 16 GtCO2 was released, primarily from deforestation, while the uptake of CO2 from regrowth on managed land, mainly after agricultural abandonment, was just under 11 GtCO2. Islam and Khan (2019) explained how climate change activists have wrongly targeted fossil fuels as the primary cause of global warming. They identified refining activities, chemical fertilizers, and other modern practices as the primary offender of the environmental integrity. Note that so-called renewable energy operations do not alleviate the problem of overall CO2 budget. Deforestation fires were lower in 2020 compared to 2019 levels, which saw the highest rates of deforestation in the Amazon since 2008. In 2019, deforestation and degradation fires were about 30% above the previous decade, while other tropical emissions, mainly from Indonesia, were twice as large as the previous decade because unusually dry conditions promoted peat burning and deforestation. These activities are not conventionally included in global warming analysis. Fossil fuel energy drove the post-industrial revolution growth in all sectors. But fossil fuel consumption has changed significantly over the past few centuries—both in terms of what and how much we burn. In the interactive chart, we see global fossil fuel consumption broken down by coal, oil, and gas since 1800. Earlier data, pre-1965, is sourced from Vaclav Smil’s work on energy transitions; this has been combined with data published in BP’s Statistical Review of World Energy from 1965 onward1 (Fig. 2.15). Fig. 2.16 shows a rise of primary energy consumption rose by 1.3% in 2019. This is down from less than half its rate in 2018 (2.8%). Growth was driven by renewables (3.2 EJ) and natural gas (2.8 EJ), which together contributed three-quarters of the increase. All fuels grew at a slower rate than their 10-year averages, apart from nuclear, with coal consumption falling for the fourth time in 6 years (20.9 EJ). The pace in nuclear energy is curious. Nuclear energy now provides about 10% of the world’s electricity from about 440 power reactors. It is touted to be the world’s second-largest source of low-carbon power (29% of the total in 2019). Nuclear power plants are operational in 31 countries worldwide. In fact, through regional transmission grids, many more countries depend in part on nucleargenerated power; Italy and Denmark, for example, get almost 10% of their electricity from imported nuclear power. The latest sustainability criterion that vilifies fossil fuel energy as carbon-intensive has led the way to nuclear energy. Primary energy consumption decreased by 4.5% last year, the first decline in energy consumption since 2009. The decline was driven largely by oil (29.7%), which accounted for almost three-quarters of the decrease. Consumption for all fuels decreased, apart from renewables (19.7%) and hydro (11.0%). Consumption fell across all the regions, with the largest declines in North America (28.0%) and Europe (27.8%). The lowest decrease was in Asia-Pacific (21.6%) due to the growth in China (12.1%), the only major country where energy consumption increased in 2020. In the other regions, the decline in consumption ranged between 27.8% in South and Central America and 23.1% in the Middle East. Fig. 2.17 shows various fractions of different energy sources. Oil continues to hold the largest share of the energy mix (33.1%). Coal is the second largest fuel but lost its share in 2019 to account for 27.0%, its lowest level since 2003. The share of both natural gas and renewables rose to record highs of 24.2% and 5.0%, respectively. Renewables have now overtaken nuclear, which makes up only 4.3% of the energy mix. The share of

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FIGURE 2.15

2. Petroleum in the big picture

World fossil fuel consumption.

hydroelectricity has been stable at around 6% for several years. Oil continues to hold the largest share of the energy mix (31.2%). Coal is the second largest fuel in 2020, accounting for 27.2% of total primary energy consumption, a slight increase from 27.1% in the previous year. The share of both natural gas and renewables rose to record highs of 24.7% and 5.7%, respectively. Renewables have now overtaken nuclear which makes up only 4.3% of the energy mix. Hydro’s share of energy increased by 0.4 percentage points last year to 6.9%, the first increase since 2014. Table 2.2 lists fuel consumption in the world for the year 2019. This trend shows the impact of the Trump era in the United States (Fig. 2.18). The share of renewables (excluding hydro) in global power generation continued its rising trend, driven by strong expansion in solar and wind energy. Renewables share in power generation reached almost 13% in 2021, higher than the share of nuclear energy (9.8%). The share of coal in the power sector increased slightly from 35% to 36% in 2021 but remained below its 2019 level. The share of gas generation in 2021 remained close to its 10-year average level. Growth in energy markets slowed in 2019 in line with weaker economic growth and a partial unwinding of some of the one-off factors that boosted energy demand in 2018. This slowdown was particularly evident in the United States, Russia, and India, each of which

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FIGURE 2.16 Global energy consumption (BP, 2022), y-axis is energy in exajoule (EJ) (1.1 exajoule 5 1018 joules).

exhibited unusually strong growth in 2018. China was the exception, with its energy consumption accelerating in 2019. As a result, China dominated the expansion in global energy markets—contributing the largest increment to demand for each individual source of energy other than natural gas, where it was only narrowly surpassed by the United States. Despite the support from China, all fuels (other than nuclear) grew at a slower rate than their 10-year averages, with coal consumption declining for the fourth time in 6 years. Nevertheless, renewables still grew by a record increment and provided the largest contribution (41%) to growth in primary energy, with the level of renewable power generation exceeding nuclear power for the first time. The slowdown in energy demand growth, combined with a shift in the fuel mix away from coal and toward natural gas and renewables, led to a significant slowing in the growth of carbon emissions, although only partially unwinding the unusually strong increase seen in 2018. Energy prices fell on the whole,

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FIGURE 2.17

2. Petroleum in the big picture

Various fractions of different energy sources on global consumption.

particularly for coal and gas where growth in production outpaced consumption leading to a build-up of inventories. Oil prices were a little lower (Fig. 2.19). In our International Energy Outlook 2021 (IEO 2021) Reference case, we project that, absent significant changes in policy or technology, global energy consumption will increase by nearly 50% over the next 30 years. Although petroleum and other liquid fuels will remain the world’s largest energy source in 2050, renewable energy sources, which include solar and wind, will grow to nearly the same level. Falling technology costs and government policies that provide incentives for renewables will lead to the growth of renewable electricity generation to meet the growing electricity

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TABLE 2.2 Fuel shares of primary energy and contributions to growth in 2019. Energy source

Consumption (exajoules)

Annual change (exajoules)

Share of primary energy

Percentage point change in share from 2018

Oil

193.0

1.6

33.1%

20.2%

Gas

141.5

2.8

24.2%

0.2%

157.9

20.9

27.0%

20.5%

Renewables

29.0

3.2

5.0%

0.5%

Hydro

37.6

0.3

6.4%

20.0%

Nuclear

24.9

0.8

4.3%

0.1%

Total

583.9

7.7

Coal a

a

Renewable power (excluding hydra) plus biofuels. From BP (2020).

FIGURE 2.18 Shares in global power generation.

demand. As a result, renewables will be the fastest-growing energy source for both Organisation for Economic Co-operation and Development (OECD) and non-OECD countries. We project that coal and nuclear use will decrease in OECD countries, although the decrease will be more than offset by increased coal and nuclear use in non-OECD countries. EIA projects that global use of petroleum and other liquids will return to prepandemic (2019) levels by 2023, driven entirely by growth in non-OECD energy consumption. We do not project OECD liquid fuel use to return to prepandemic levels at any point in the next 30 years, in part because of increased fuel efficiency. Ever since the oil embargo of 1972, the world has been gripped with the fear of “energy crisis.” US President Jimmy Carter, in 1978, told the world in a televised speech that the

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FIGURE 2.19

2. Petroleum in the big picture

(A) From EIA (2021a). (B) From BP (2022).

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world was in fact running out of oil at a rapid pace—a popular Peak Oil theory of the time—and that the United States had to wean itself off of the commodity. Since the day of that speech, worldwide oil output has actually increased by more than 30%, and known available reserves are higher than they were at that time. This hysteria has survived the era of Reaganomics, President Clinton’s cold war dividend, President G.W. Bush’s post9
11 era of “fearing everything but petroleum” and today even the most ardent supporters of petroleum industry have been convinced that there is an energy crisis looming and that is only a matter of time; we will be forced to switch no-petroleum energy source. During President Obama’s time, there had been a marked shift toward so-called renewable energy and the background of “only a carbon tax can fix the climate change debacle” mantra was firmly established. President Trump has strived to undo much of those biases away from petroleum resources, but the scientific community remains unconvinced. In this chapter, we deconstruct some of the hysteria and unscientific bias that have gripped the scientific community as well as left leaning segment of the general public. The general public is being prepared to face an energy crisis that is perceived to be forthcoming. Since the demand for oil is unlikely to decline it inevitably means that the price will increase, probably quite dramatically. This crisis attributed to peak oil theory is proposed to be remedied with (1) austerity measures in order to decrease dependence on energy, possibly decreasing per capita energy consumption and (2) alternatives to fossil fuel. None of these measures seem appealing because any austerity measure can induce imbalance in the economic system that is dependent on the spending habit of the population and any alternative energy source may prove to be more expensive than fossil fuel. These concerns create panic, which is beneficial to certain energy industries, including biofuel, nuclear, wind, and others. Added to this problem is the recent hysteria created based on the premise that oil consumption is the reason behind global warming. This in itself has created opportunities with many sectors engaged in carbon sequestration. In general, there has been a perception that solar, wind, and other forms of “renewable” energy are more sustainable or less harmful to the environment than its petroleum counterpart. It is stated that renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Chhetri and Islam (2008) have demonstrated that the claim of harmlessness and absolute sustainability is not only exaggerated, but also it is not supported by science. However, irrespective of scientific research, this positive perception translated into global public support. One such survey was performed by Ipsos Global in 2011 that found very favorable rating for nonfossil fuel energy sources (Fig. 2.20). Perception does have economic implications attached to it. The Ipsos study found 75% agreeing to the slogan “scientific research makes a direct contribution to economic growth in the United Kingdom.” However, in the workshops, although participants agreed with this, they did not always understand the mechanisms through which science affects economic growth. There is strong support for the public funding of scientific research, with three-quarters (76%) agreeing that “even if it brings no immediate benefits, research which advances knowledge should be funded by the Government.” Very few (15%) think that “Government funding for science should be cut because the money can be better spent elsewhere.” This is in spite of public support for cutting government

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FIGURE 2.20

From EIA (2021a).

FIGURE 2.21

Public perception toward energy sources (Ipsos, 2011).

spending overall. It is not any different in the United States, for which perception translates directly into pressure on the legislative body, resulting in an improved subsidy for certain activities. The Energy Outlook considers a range of alternative scenarios to explore different aspects of the energy transition (Fig. 2.21). The scenarios have some common features, such as a significant increase in energy demand and a shift toward a lower carbon fuel mix, but differ in terms of particular policy or technology assumptions. In Fig. 2.22, Evolving Transition (ET) scenario is a direct function of public perception that dictates government policies, technology, and social preferences. Some scenarios focus on particular policies that affect specific fuels or technologies, for example, a ban on sales of ICE cars, a greater policy push to renewable energy, or weaker policy support for a switch from coal to gas considered, for example, faster and even faster transitions.

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FIGURE 2.22 Energy outlook for 2040 as compared to 2016 under various scenarios (*Renewables include wind, solar, geothermal, biomass, and biofuels). Source: From BP Report, 2018. https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/investors/bp-annual-report-and-form-20f-2018.pdf.

2.4 What is “green”? A new Ipsos survey of public attitudes to the nuclear energy industry on behalf of the Nuclear Industry Association shows the industry to be favorably regarded on balance, a stark contrast with the position just 5 years ago. Favorable opinion has reached 35% and unfavorable opinion is 26%; a complete reversal of the position in December 2002, when favorable opinion was just 21% and unfavorable opinion was 33%. That was the public opinion background against which the Government framed the 2003 Energy White Paper which concluded that nuclear was “an unattractive option.” This more favorable viewpoint is against a background of increasing familiarity with the industry in recent years. Familiarity actually fell after 2002 to a low of 17% (who feel they know “at least a fair amount” about the industry), but since then, as media interest in a possible nuclear revival has placed the issues regularly in front of people, has grown strongly to 27% in 2007. This improved familiarity with the industry, and a recent more positive view of it has gone hand in hand with growing net support for replacement nuclear newbuild. This year’s survey shows again the supporters of newbuild outweighing the opposers (36% support; 27% oppose), but it is possible that net support peaked in 2006. Both support and opposition have fallen a little this year, and we can speculate this may be due to increasing levels of confusion over the opposing arguments and the greater volume of information available. The proportion of the public who are neutral, undecided or simply don’t know has this year reached its peak. People are less sure than ever of what they believe, and less inclined to give the benefit of the doubt to either side. For the first time since 2002, the upward curve in expectations that nuclear energy will be a major contributor to Britain’s energy supplies in the future has faltered and reversed. People are not so sure now, even though they still support nuclear newbuild on balance, maybe because they have seen little progress so far toward new construction their faith is shaken. This may be partly an effect of the successful Greenpeace challenge to the first Energy Review, which delayed progress on a number of fronts and necessitated a hurried rerunning of the consultation process.

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Despite these interruptions to the trends, however, a decisive majority of the population still agrees that Britain needs a mix of energy sources to ensure a reliable supply of electricity, including nuclear power and renewable energy sources—65% agree; 10% disagree. This, too, is down a little this year; agreement is down seven points, but disagreement is up only two points, implying again a net shift to the neutral or undecided. The research was conducted online by Ipsos on behalf of the Energy Saving Trust among a total of 2067 adults aged 16
75 in the United Kingdom from 18th to 21st January 2014 via its Online iOmnibus Survey (Ipsos, 2014). In 2014, Ipsos was commissioned by the Energy Saving Trust to conduct a survey on public perception and understanding of what actions within the home can save money as part of the Big energy savings. Vast majority of them did not see this as an issue (Figs. 2.23
2.25). Arguably, the single most important element of the energy system needed to address both aspects of the Paris Agreement—respond to the threat of climate change and support sustainable growth—is the need for rapid growth in renewable energy. Considering the overall goal, 84% of our current energy need is met by fossil fuels. That is down just two percentage points from 20 years ago. More importantly, 97% of all global transportation is fueled by petroleum products. When it is peddled that renewables will cover most of the energy in the near future, it is preposterous lie. In the last 2 decades, some five trillion dollars of government investment in “green energy” created little tangible benefit. Islam (2021) discussed why transitioning in “green energy” is absurd. Consider the amount of minerals that have to be mined to meet the infrastructure requirement of “green energy.” The minerals required will need 10 times more mining than what is currently done. The minerals are in general, copper, iron ore, silicon, nickel, chromium, zinc, cobalt, lithium, graphite, and rare earth metals, such as

FIGURE 2.23

Growth in renewables.

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FIGURE 2.24 China has surpassed its 2020 solar PV target Image: IEA (WEF, 2018).

FIGURE 2.25 Denmark is expected to be the world leader by 2022. Source: Image from IEA.

neodymium. These are needed to manufacture motors, turbine blades, solar panels, batteries, and hundreds of other industrial components. That also takes lots of energy, which requires even more mining. Shares of these mines are diverse and exploitation of these mines is dependent on local environmental regulations. Table 2.3 lists some of these mineral shares globally (Table 2.4).

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TABLE 2.3 Global shares of selected minerals. Cobalt reserves Thousand tonnes

At end of 2021

Share

Reserve/production (R/P) ratio

Australia

1400

20.5%

251

Canada

220

3.2%

57

China

80

1.2%

36

Cuba

500

7.3%

126

Democratic Republic of Congo

3500

51.4%

38

Madagascar

100

1.5%

50

Morocco

13

0.2%

6

New Caledonia

64

0.9%

-

Papua new Guinea

47

0.7%

16

Philippines

260

3.8%

60

Russian federation

250

3.7%

38

South Africa

40

0.6%

33

Zambia

270

4.0%

941

Rest of world*

69

1.0%

22

Total world

6813.0

100.0%

52

Natural graphite reserves Thousand tonnes

At end of 2021

Share

R/P ratio

Brazil

70,000

19.2%

737

Canada

648

0.2%

84

China

73,000

20.0%

89

India

8000

2.2%

199

Madagascar

26,000

7.1%

295

Mexico

3100

0.8%

1867

Mozambique

25,000

6.9%

347

Norway

600

0.2%

95

Russian Federation

25,703

7.0%

1688

Sri Lanka

1500

0.4%

349

Turkey

90,000

24.7%

5919

Ukraine

13,761

3.8%

4322

Rest of world*

27,600

7.6%

510

Total world

364,912

100%

298 (Continued)

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TABLE 2.3 (Continued) Lithium reserves Thousand tonnes

At end of 2021

Share

R/P ratio

Argentina

2200

10.9%

369

Australia

5700

28.1%

103

Brazil

95

0.5%

63

Chile

9200

45.4%

354

China

1500

7.4%

107

Portugal

60

0.3%

67

United States

750

3.7%

833

Zimbabwe

220

1.1%

183

Rest of world*

530

2.6%

5221

Total world

20,255

100.0%

191

Rare earth metals reserves Thousand tonnes

At end of 2021

Share

R/P ratio

Australia

4000

3.2%

177

Brazil

21,000

17.0%

42000

China

44,000

35.7%

262

India

6900

5.6%

1367

Madagascar

189

0.2%

59

Russian federation

19,380

15.7%

7454

Thailand

n/a

n/a

n/a

United States

1800

1.5%

42

Rest of world*

26,040

21.1%

823

Total world

123,309

100%

433

*Rest of the world, which includes all the countries other than the ones cited above.

A recent World Bank report summarized this dilemma as “Furthermore, the technologies assumed to populate the clean energy shift (wind, solar, hydrogen, and electricity systems) are in fact significantly MORE material intensive in their composition than current traditional fossil-fuel-based energy supply systems (Vidal et al., 2013).” Considering that raw materials account for 50%
70% of the costs to manufacture both solar panels and batteries and these “renewables” only account for a few percentages of the global energy need, World Bank view is an understatement of delirious proportion. This narrative is based on the premise: carbon is bad—a delirious premise. For instance, Vidal et al. (2013, p. 894) state:

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TABLE 2.4 Top five copper reserves. Country

Reserve (Million MT)

1. Chile

200

2. Peru

92

3. Australia

88

4. Russia

61

5. Mexico

53

Renewable power resources coming from the sun (175,000 TW), geothermal flux (40
50 TW) and gravity (e.g., tidal energy, 3
4 TW) could supply a thousand times our current and future (2050) global energy needs, estimated at 140 3 103 TWh (16 TW) and 280 3 103 TWh (32 TW), respectively. However, most renewable energy sources are diffuse and intermittent. Harnessing this energy requires complex infrastructure distributed over large areas, both on land and at sea.

Stating that 175,000 TW of solar energy or 3
4 TW of tidal energy is available to compete with fossil fuel is utterly absurd. Consider an equivalent wording, such as 500 billion tons of carbon being reported as “available energy source” just because that much biomass is available on earth. In the same token, consider touting that 300,000,000 trillion cubic feet of gas is available to tap because that much hydrate is available on earth. Energy has no meaning if it cannot be harnessed and put to use for human activities and to achieve that level of usefulness, “renewable” energy schemes have to spend a lot more energy per watt than any fossil fuel. The problem does not end there. China is the world leader in renewable energy production. It is currently the world’s largest producer of wind and solar energy (OECD, 2022), and the largest domestic and outbound investor in renewable energy (Jaeger et al., 2017). Among the top three nations, China is the undisputed renewable growth leader, accounting for over 40% of the total global clean energy mix by 2022. China has also already surpassed its 2020 solar panel target, and the IEA says it expects the country to exceed its wind target in 2019. China is also the global market leader in hydropower, bioenergy for electricity and heat, and EV. Perhaps surprisingly, the United States is the second-largest growth market for renewables. Despite President Donald Trump’s decision in 2017 to pull out of the Paris Agreement, renewable projects in the US continued to benefit from multiyear federal tax incentives and state-level policies for distributed solar panels in the coming years. Meanwhile, India overtook the EU. In India, renewable capacity is expected to more than double by 2022. Solar and wind represent 90% of India’s capacity growth, which is the result of auctions for contracts to develop power-generation capacity that has yielded some of the world’s lowest prices for both technologies, the report says. Because of these factors, India’s growth between now and 2022 is, for the first time, expected to be higher than in the EU. Incidentally, renewables growth across the EU is 40% lower than between 2011 and 2016, with the market hampered by weaker electricity demand, overcapacity, and a lack of

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clarity on the capacity volumes that will be auctioned. What is more, policy uncertainty within the bloc beyond 2020 remains high. However, the report says if the new EU Renewable Energy Directive covering the post2020 period is adopted, it would address this challenge by requiring a 3-year period for policies to support renewable energy, thereby improving the market’s predictability. Fortunately, if you look at individual EU member states, the outlook seems brighter. Denmark, for example, is expected to generate 69% of its energy from renewable sources by 2022, making it the world leader. Ireland is second, with the report predicting it will generate one-third of its energy needs from renewable sources. In other European countries, including Spain, Germany, and the United Kingdom, the share of wind and solar will exceed 25% of total generation, the report estimates. Proposals to build mines in the United States and, increasingly almost everywhere else, meet fierce opposition if not outright bans. To give just one example, in 2022, the Biden Administration canceled a proposed copper and nickel mine in northern Minnesota. This was after years of delays, navigating a maze of environmental regulations. The main driver of renewables was China, which accounted for roughly half of the global increase in wind and solar capacity. The expansion in Chinese wind capacity (72 GW) is particularly striking and it is likely that some of the reported increase reflects various changes to Chinese subsidy and accounting practices. But even controlling for that, it seems clear that 2020 was a record year for the build-out of wind and solar capacity. Viewed over a slightly longer period, wind and solar capacity more than doubled between 2015 and 2020, increasing by around 800 GW, which equates to an average annual increase of 18%. To put that in context, in BP’s Rapid and Net Zero scenarios, wind and solar capacity increase at an average annual rate of around 14% and 18%, respectively over the next 10 years. So, the current pace of growth is broadly on track with those scenarios. The challenge is to maintain the recent pace of growth as the overall size of renewable energy expands. In that context, what has underpinned the strong growth over the past 5 years? Along with many other forecasters, we materially underestimated the growth of wind and solar power over the past 5 years. A key factor underpinning this underestimation is that costs of renewable energy have fallen by far more than projected in BP’s 2016 Energy Outlook. In the meantime, it is predicted that the so-called decarbonization scheme is in full swing in favor of energy sources other than fossil fuel.4 The aim is to reduce GHG emissions dramatically, ignoring the fact that nonpetroleum energy sources are no less toxic than petroleum emissions (Islam and Khan, 2019). BP (2019) predicts that EV will play a major role in lowering emissions from transport and boasts about providing a network of 6500 charging points across the United Kingdom and plan to roll out ultra-fast charging on our forecourt network. The assumption in all these is, somehow electric cars are environmentally friendly. This is contrary to the scientific analysis conducted over a 4

Even electric cars are considered to be a product of decarbonization irrespective of the source of electrical energy.

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FIGURE 2.26

2. Petroleum in the big picture

Energy growth of various energy sources.

decade ago by Chhetri and Islam (2008), who showed that EVs are far more toxic to the environment and far less efficient than regular vehicles, run on ICE. BP further predicts that by 2040, half of Europe’s cars and one-third of world’s vehicles will avoid having ICEs. This process of “decarbonization” is further accelerated by introducing electrification using “renewables,” hydrogen, e-fuel,5 and even nuclear energy. Clearly, the world stage is ready to accept even nuclear in favor of “decarbonization.” For instance, Kann (2019) indicated nuclear option as the number one priority to cut down GHG emissions. Fig. 2.26 shows the growth of various energy sources. Only renewable energy made gains. Meanwhile, CO2 emission declined. It is tempting to conclude that the decline is due to reduction in fossil fuel consumption. This is not scientific as each renewable technology end up causing greater CO2 emission of the entire life cycle is considered.

2.4.1 Fast-tracking renewables? For the world to transition to low-carbon electricity, energy from these sources needs to be cheaper than electricity from fossil fuels. Fossil fuels dominate the global power supply because until very recently electricity from fossil fuels was far cheaper than electricity from renewables. This has dramatically changed within the last decade. In most places, in the world, power from new renewables is now cheaper than power from new fossil fuels. 5

E-fuel involves synthetic fuel, made out of nonpetroleum carbon and is branded as “carbon free” (Palmer, 2015).

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The fundamental driver of this change is that renewable energy technologies follow learning curves, which means that with each doubling of the cumulative installed capacity, their price declines by the same fraction. The price of electricity from fossil fuel sources, however, does not follow learning curves so that we should expect that the price difference between expensive fossil fuels and cheap renewables will become even larger in the future. This is an argument for large investments into scaling up renewable technologies now. Increasing installed capacity has the extremely important positive consequence that it drives down the price and thereby makes renewable energy sources more attractive, earlier. In the coming years, most of the additional demand for new electricity will come from low- and middle-income countries; we have the opportunity now to ensure that much of the new power supply will be provided by low-carbon sources. Falling energy prices also mean that the real income of people rises. Investments to scale up energy production with cheap electric power from renewable sources are therefore not only an opportunity to reduce emissions but also to achieve more economic growth—particularly for the poorest places in the world. The world’s energy supply today is neither safe nor sustainable. What can we do to change this and make progress against this twin problem of the status quo? To see the way forward we have to understand the present. Today fossil fuels—coal, oil, and gas—account for 79% of the world’s energy production and as the chart below shows they have very large negative side effects. The bars to the left show the number of deaths and the bars on the right compare the GHG emissions. My colleague Hannah Ritchie explains the data in this chart in detail in her post “What are the safest sources of energy?.” This makes two things very clear. As the burning of fossil fuels accounts for 87% of the world’s CO2 emissions, a world run on fossil fuels is not sustainable, and they endanger the lives and livelihoods of future generations and the biosphere around us. And the very same energy sources lead to the deaths of many people right now—the air pollution from burning fossil fuels kills 3.6 million people in countries around the world every year; this is 6 times the annual death toll of all murders, war deaths, and terrorist attacks combined.1 It is important to keep in mind that electric energy is only one of several forms of energy that humanity relies on; the transition to low-carbon energy is therefore a bigger task than the transition to low-carbon electricity.2 What the chart makes clear is that the alternatives to fossil fuels—renewable energy sources and nuclear power—are orders of magnitude safer and cleaner than fossil fuels. Why then is the world relying on fossil fuels? Fossil fuels dominate the world’s energy supply because in the past they were cheaper than all other sources of energy. If we want the world to be powered by safer and cleaner alternatives, we have to make sure that those alternatives are cheaper than fossil fuels (Fig. 2.27). Table 2.5 lists shares of various energy sources. Primary energy consumption rose by 1.3% in 2019, below its 10-year average rate of 1.6% per year, and much weaker than the 2.8% growth seen in 2018. By region, consumption fell in North America, Europe, and Commonwealth of Independent States (CIS), and growth was below average in South and

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FIGURE 2.27

Comparison of various energy sources.

TABLE 2.5 Fuel shares of primary energy and contributions to growth in 2019 (BP, 2020). Energy source

Consumption (exajoule)

Annual change (exajoule)

Share of primary energy

Percentage point change in share from 2018

Oil

193.0

1.6

33.1%

20.2%

Gas

141.5

2.8

24.2%

0.2%

157.9

20.9

27.0%

20.5%

Renewables

29.0

3.2

5.0%

0.5%

Nuclear

24.9

0.8

4.3%

0.1%

Hydro

37.6

0.3

6.4%

20.0%

Total

583.9

7.7

Coal a

a

Renewable power (excluding hydro) plus biofuels.

Central America. Demand growth in Africa, Middle East, and Asia was roughly in line with historical averages. China was by far the biggest individual driver of primary energy growth, accounting for more than three-quarters of net global growth. India and Indonesia were the next largest contributors, while the United States and Germany posted the largest declines in energy terms. There is a shift in terms of energy consumption habits and lifestyle between the eastern and western countries. Looking at energy by fuel, 2019 growth was driven by renewables, followed by natural gas, which together contributed over three-quarters of the net increase. The share of both renewables and natural gas in primary energy increased to record highs.

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Meanwhile, coal consumption declined, with its share in the energy mix falling to its lowest level since 2003. BP (2020) summarized coal and other energy consumption as follows: Coal 1. Coal consumption declined by 0.6% and its share in primary energy fell to its lowest level in 16 years (27%). 2. Increases in coal consumption were driven by the emerging economies, particularly China (1.8 EJ) and Indonesia (0.6 EJ). However, this was outweighed by a sharp fall in OECD demand, which fell to its lowest level in our data series (which starts in 1965). 3. Global coal production rose by 1.5%, with China and Indonesia providing the only significant increases (3.2 EJ and 1.3 EJ, respectively). The largest declines came from the US (21.1 EJ) and Germany (20.3 EJ). Renewables, hydro, and nuclear energy 1. Renewable energy (including biofuels) posted a record increase in consumption in energy terms (3.2 EJ). This was also the largest increment for any source of energy in 2019. 2. Wind provided the largest contribution to renewables growth (1.4 EJ) followed closely by solar (1.2 EJ). 3. By country, China was the largest contributor to renewables growth (0.8 EJ), followed by the United States (0.3 EJ) and Japan (0.2 EJ). 4. Hydroelectric consumption rose by a below-average 0.8%, with growth led by China (0.6 EJ), Turkey (0.3 EJ), and India (0.2 EJ). 5. Nuclear consumption rose by 3.2% (0.8 EJ), its fastest growth since 2004. China (0.5 EJ) and Japan (0.1 EJ) provided the largest increments.

2.5 Role of oil and gas Fossil fuel consumption has increased significantly over the past half-century, around eightfold since 1950, and roughly doubled since 1980. However, the types of fuel we rely on have also shifted, from solely coal toward a combination with oil, and then gas. Today, coal consumption is falling in many parts of the world. Meanwhile, oil and gas are still growing quickly. BP (2020) gives the following update for the year 2019. Fig. 2.28 shows world energy balances of the last three decades as reported by IEA (2020). The IEA’s World Energy Balances presents comprehensive energy balances for all the world’s largest energy-producing and consuming countries. It contains detailed data on the supply and consumption of energy for 150 countries and regions, including all OECD countries, over 100 other key countries, as well as world totals. Energy data are generally collected independently across different commodities. Energy statistics are the simplest format to present all the data together, assembling the individual balances of all products, each expressed in its own physical unit (e.g., TJ for natural gas and kt for coal). These are called commodity balances. However, energy products can be converted into one another through a number of transformation processes. Therefore it is very useful to also develop one comprehensive national energy balance, to understand

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FIGURE 2.28 The historical world energy balances. Source: From IEA (2020). World Energy Outlook 2020, https:// www.iea.org/reports/world-energy-outlook-2020.

how products are transformed into one another, and to highlight the various relationships among them. By presenting all the data in a common energy unit, the energy balance allows users to see the total amount of energy used and the relative contribution of each different source, for the whole economy and for each individual consumption sector; to compute the different fuel transformation efficiencies; to develop various aggregated indicators and to estimate CO2 emissions from fuel combustion. The energy balance is a natural starting point to study the evolution of the domestic energy market, forecast energy demand, monitor impacts of energy policies, and assess potential areas for action. The energy balance takes the form of a matrix, where columns present all the different energy sources (products) categories and rows represent all the different “flows,” grouped in three main blocks as follows: energy supply, transformation/energy use, and final consumption (Table 2.6). To develop an energy balance from the set of commodity balances, the two main steps are as follows: 1. All the data are converted to a common energy unit—also allowing to compute a “total” product. 2. Some reformatting is performed to avoid double counting when summing all products together. It takes two main steps to develop an energy balance from the set of commodity balances. First, all the data are converted to a common energy unit. For the IEA, this means converting data into tonnes of oil equivalent (toe), defined as 107 kilocalories (41.868 gigajoules). Second, some reformatting is performed to avoid double counting when summing data for all products together. For example, the production of secondary products (e.g., motor gasoline)

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TABLE 2.6 Some useful definitions of sustainability factors. Flow

Short name

Definition

Transformation processes

TOTTRANF

Transformation processes comprise the conversion of primary forms of energy to secondary and further transformation (e.g., coking coal to coke, crude oil to oil products, and fuel oil to electricity). Inputs to transformation processes are shown as negative numbers and output from the process is shown as a positive number. Transformation losses will appear in the “total” column as negative numbers.

Main activity producer electricity plants

MAINELEC

Refers to plants that are designed to produce electricity only. If one or more units of the plant is a combined heat and power (CHP) unit (and the inputs and outputs cannot be distinguished on a unit basis), then the whole plant is designated as a CHP plant. Main activity producers generate electricity for sale to third parties, as their primary activity. They may be privately or publicly owned. Note that the sale need not take place through the public grid

Autoproducer electricity plants

AUTOELEC

Refers to plants that are designed to produce electricity only. If one or more units of the plant are a CHP unit (and the inputs and outputs cannot be distinguished on a unit basis), then the whole plant is designated as a CHP plant. Autoproducer undertakings generate electricity wholly or partly for their own use as an activity that supports their primary activity. They may be privately or publicly owned

Main activity producer plants

MAINCHP

Refers to plants that are designed to produce both heat and electricity (sometimes referred to as cogeneration power stations). If possible, fuel inputs and electricity/heat outputs are on a unit basis rather than on a plant basis. However, if data are not available on a unit basis, the convention for defining a CHP plant noted above should be adopted. Main activity producers generate electricity and/or heat for sale to third parties, as their primary activity. They may be privately or publicly owned. Note that the sale need not take place through the public grid.

Autoproducer CHP plants

AUTOCHP

Refers to plants that are designed to produce both heat and electricity (sometimes referred to as cogeneration power stations). If possible, fuel inputs and electricity/heat outputs are on a unit basis rather than on a plant basis. However, if data are not available on a unit basis, the convention for defining a CHP plant noted above should be adopted. Note that for autoproducer CHP plants, all fuel inputs to electricity production are taken into account, while only the part of fuel inputs to heat sold is shown. Fuel inputs for the production of heat consumed within the autoproducer’s establishment are not included here but are included with figures for the final consumption of fuels in the appropriate consuming sector. Autoproducer undertakings generate electricity and/or heat, wholly or partly for their own use as an activity, which supports their primary activity. They may be privately or publicly owned.

Main activity producer heat plants

MAINHEAT Refers to plants (including heat pumps and electric boilers) designed to produce heat only and who sell heat to a third party (e.g., residential, commercial, or industrial consumers) under the provisions of a contract. Main activity producers generate heat for sale to third parties, as their primary activity. They may be privately or publicly owned. Note that the sale need not take place through the public grid. (Continued)

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TABLE 2.6 (Continued) Flow

Short name

Definition

Autoproducer heat plants

AUTOHEAT Refers to plants (including heat pumps and electric boilers) designed to produce heat only and who sell heat to a third party (e.g., residential, commercial, or industrial consumers) under the provisions of a contract. Autoproducer undertakings generate heat, wholly or partly for their own use as an activity, which supports their primary activity. They may be privately or publicly owned.

Heat pumps

THEAT

Includes heat produced by heat pumps in transformation. Heat pumps that are operated within the residential sector where the heat is not sold are not considered a transformation process and are not included here—the electricity consumption would appear as residential use.

Electric boilers

TBOILER

Includes electric boilers used to produce heat.

Chemical heat for electricity production

TELE

Includes heat from chemical processes, which is used to generate electricity.

Gas works

TGASWKS

Includes the production of recovered gases (e.g., blast furnace gas and oxygen steel furnace gas). The production of pig iron from iron ore in blast furnaces uses fuels for supporting the blast furnace charge and providing heat and carbon for the reduction of the iron ore. Accounting for the calorific content of the fuels entering the process is a complex matter as transformation (into blast furnace gas) and consumption (heat of combustion) occur simultaneously. Some carbon is also retained in the pig iron; almost all of this reappears later in the oxygen steel furnace gas (or converter gas) when the pig iron is converted to steel. In the 1992/1993 annual questionnaires, member countries were asked for the first time to report in transformation processes the quantities of all fuels (e.g., pulverized coal injection [PCI] coal, coke oven coke, natural gas, and oil) entering blast furnaces and the quantity of blast furnace gas and oxygen steel furnace gas produced. The IEA Secretariat then needed to split these inputs into the transformation and consumption components. The transformation component is shown in the row blast furnaces in the column appropriate for the fuel, and the consumption component is shown in the row iron and steel, in the column appropriate for the fuel. The IEA Secretariat decided to assume a transformation efficiency such that the carbon input into the blast furnaces should equal the carbon output. This is roughly equivalent to assuming an energy transformation efficiency of 40%.

Gas works

TGASWKS

Includes the manufacture of town gas. Note: in the summary balances, this item also includes other gases blended with natural gas (TBLENDGAS).

Oil refineries

TREFINER

Covers the use transformation of hydrocarbons for the manufacture of finished oil products.

Petrochemical plants

TPETCHEM Covers backflows returned from the petrochemical industry. Note that backflows from oil products that are used for nonenergy purposes (e.g., white spirit and lubricants) are not included here, but in nonenergy use. (Continued)

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TABLE 2.6 (Continued) Flow

Short name

Definition

Coal liquefaction plants

TCOALLIQ

Includes coal, oil, and tar sands used to produce synthetic oil.

Gas-to-liquids (GTL) plants

TGTL

Includes natural gas used as feedstock for the conversion to liquids, for example, the quantities of fuel entering the methanol production process for transformation into methanol.

Blast furnaces

EBLASTFUR Represents the energy that is used in blast furnaces.

Nuclear industry

ENUC

Represents the energy used in the nuclear industry.

appears in the production row in commodity balances but is reported as an output of the relevant transformation (e.g., oil refineries) in an energy balance, as the production row only refers to production of primary products (e.g., crude oil). The main methodological choices underlying energy balances that can differentiate the final layout are as follows: “net” versus “gross” energy content (where the IEA uses net), calorific values (where the IEA uses national data wherever possible), and “primary energy equivalent” conventions. The world is witnessing several global environmental challenges. As energy production and use are major causes of environmental problems, proper choice of energy technology can have a significant impact on reversing these global problems, such as global warming and climate change. With the incessant campaign against fossil fuels, thus targeting carbon as the “enemy,” every energy source other than fossil fuel has been touted as sustainable. For instance, “sustainable petroleum technology” is vastly considered to be an oxymoron while others including nuclear energy are considered to be one of the most efficient and cleanest energy technologies. Particularly, nuclear energy was projected as one of the cheapest energy sources and a reliable alternative to fossil fuel. This was also promoted as an effective solution to reduce CO2, a precursor to the global warming. However, nuclear energy has several environmental, social, and economic issues that have not yet been addressed and remains the most controversial energy source to date (Chhetri and Islam, 2008). Current scientific analyses portray nuclear energy as one of the most efficient technologies. However, these scientific analyses only consider “local efficiency” as the measure of true efficiency of a system. If “global efficiency,” which includes long-term environmental sustainability, is considered, the efficiency picture becomes gloomy for nuclear energy. This aspect will be discussed in a latter section, but the important here is only fossil fuel uses its own energy throughout the energy cycle. As can be seen in Table 2.6, all energy transformations use petroleum or fossil fuel technology. This is in contrast to other energy sources. For instance, each wind turbine is predominantly made of steel (71%
79% of total turbine mass), fiberglass, resin, or plastic (11%
16%), iron or cast iron (5%
17%), copper (1%), and aluminum (0%
2%). State-of-the-art wind turbine blades are made of carbon fiber, which consists of layers of plastics and plastic resin, both of which are derived from oil and natural gas feedstocks. This involves a very high energy budget supported by fossil fuels. Solar energy, on the hand, relies on forms of silicon that are used for the construction, namely, single-crystalline, multicrystalline, and amorphous. Other materials used for the construction of photovoltaic cells are polycrystalline thin films

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such as copper indium diselenide, cadmium telluride, and gallium arsenide. These materials have high energy budget requirements. Wind turbines and solar panels cannot be made solely from other wind turbines and solar panels. Fossil fuels are required to manufacture wind and solar equipment, transport, and construct them and provide backup electricity when the wind is not blowing and the sun is not shining. Wind and solar facilities currently require massive quantities of steel and concrete, both of which require oil and natural gas in their manufacturing processes. The amount of steel required for wind and solar to replace fossil fuels exceeds the world’s capability to produce it for decades. The most significant fossil fuel requirement for wind and solar is to provide the backup electric-generating capacity needed when the wind is not blowing and the sun is not shining. Fast-reacting fossil fuel-based installations—such as highly efficient, combined-cycle, natural gas-fired electric generating plants—are the only viable options to avoid brownouts and blackouts. This practical problem becomes that of absurdity when one considers the fact that an effective takeover by wind energy of just coal would require 10 billion tons of steel, whereas the total annual global production of steel is only 1.6 billion tons. Conventional sustainability analyses do not consider these factors. Chhetri and Islam (2008) conducted a critical review of energy budget issues, along with environmental, economical, and social aspects. By using a newly developed definition of “global efficiency,” ηg, first developed by Khan and Islam (2012), Chhetri and Islam (2008) showed that solar, wind, and nuclear energy technologies are much less efficient than oil and gas technology. BP, 2020, Statistical Review of World Energy, https://www.bp.com/en/global/corporate/ energy-economics/statistical-review-of-world-energy.html. Oil 1. Oil consumption grew by a below-average 0.9 million barrels per day (b/d), or 0.9%. Demand for all liquid fuels (including biofuels) rose by 1.1 million b/d and topped 100 million b/d for the first time. 2. Oil consumption growth was led by China (680,000 b/d) and other emerging economies, while demand fell in the OECD (2290,000 b/d). 3. Global oil production fell by 60,000 b/d as strong growth in US output (1.7 million b/d) was more than offset by a decline in OPEC production (22 million b/d), with sharp declines in Iran (21.3 million b/d), Venezuela (2560,000 b/d), and Saudi Arabia (2430,000 b/d). 4. Refinery utilization fell sharply by 1.2 percentage points as capacity rose by 1.5 million b/d and throughput remained relatively unchanged. Natural gas 1. Natural gas consumption increased by 78 billion cubic meters (bcm), or 2%, well below the exceptional growth seen in 2018 (5.3%). Nevertheless, the share of gas in primary energy rose to a record high of 24.2%. Increases in gas demand were driven by the United States (27 bcm) and China (24 bcm), while Russia and Japan saw the largest declines (10 and 8 bcm respectively).

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2. Gas production grew by 132 bcm (3.4%), with the United States accounting for almost two-thirds of this increase (85 bcm). Australia (23 bcm) and China (16 bcm) were also key contributors to growth. 3. Inter-regional gas trade expanded at a rate of 4.9%, more than double its 10-year average, driven by a record increase in LNG of 54 bcm (12.7%). 4. LNG supply growth was led by the United States (19 bcm) and Russia (14 bcm), with most incremental supplies heading to Europe: European LNG imports (149 bcm) rose by more than two-thirds (Fig. 2.29). In 2019, 81% of the global population lived in countries where the average energy demand per capita was less than 100 GJ/head, two percentage points more than 20 years ago. However, the share of the global population consuming less than 75 GJ/head declined from 76% in 1999 to 57% last year. Average energy demand per capita in China increased from 17 GJ/head in 1979 to 99 GJ/head in 2019. Ever since the oil price declined in 2014 from a historic high oil price, the world oil market has become vulnerable to uncertainty and economic gloom. It is difficult to separate this oil price issue from the perception of environmental concerns. Even more difficult is to decipher the role of this perception on energy pricing of both renewable and nonrenewable resources (Islam et al., 2018). Figs. 2.30 and 2.31 show long-term oil prices while Fig. 2.32 shows the same for natural gas. As discussed by Islam et al. (2018), the oil price is not governed by supply and demand, it is rather governed by global politics. That politics has become that of contempt of carbon fuel since the installation of Clinton presidency. With Al Gore’s anticarbon agenda, along with support from IPCC, the energy politics has been governed by what Islam and Khan (2019) called “climate change hysteria.” Even during the Bush presidency,

FIGURE 2.29 Energy per capita, distribution across countries.

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FIGURE 2.30 Petroleum is the driver of world economy and is driven by political events. Source: Data from EIA, 2018. China surpassed the United States as the world’s largest crude oil importer in 2017, December 31, 2018.

with the war on terror, the world had little time to reflect on the science of global warming and the likes of Conservatives, such as President G W Bush resorted to the rhetoric of “oil addiction.” As a consequence, from the mid-1980s to September 2003, the inflationadjusted price of a barrel of crude oil on NYMEX was generally underUS$25/barrel. This would mark oil as the most stable commodity. During 2003, the price rose above $30, reached $60 by August 11, 2005, and peaked at $147.30 in July 2008. This steady rise was first triggered by war on terror shortly after the 9/11 terror attack in New York. During this time, the United States engaged in costly wars in the Middle East. At the same time, the demand of oil in China soared (IEA, 2020). Although much of the energy demand of China was offset by coal, the shear volume of the demand affected the global pricing. It is also true that during the same period, the US dollar value dropped (Islam et al., 2018). Added to these is the fact that global petroleum reserve declined (Islam, 2014) and the world became vulnerable to the financial collapse in 2008, which triggered a oil price decline that reverberates until today (Islam et al., 2018). The global financial crisis causes a bubble-bursting sell-off. Prices plummet 78.1% from July to December. The financial collapse of 2008, along with the recession, created a new cycle for oil prices. The recession caused demand for energy to shrink in late 2008, with oil prices

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FIGURE 2.31 Politics and oil price.

collapsing from the July 2008 high of $147 to a December 2008 low of $32. This sudden drop in such a short time remains one of the most important collapse in the history of oil and gas. As the economy recovered, despite losses in bailouts and perpetual wars in the Middle East, oil prices stabilized by August 2009 and generally remained in a broad trading range between $70 and $120 through November 2014, eventually returning to 2003 precrisis levels by early 2016. In the global market, during 2011 through 2014, riots and protests from the Arab Spring and the Libyan civil war disrupted the regional output. During 2008 through 2014, unconventional oil and gas, empowered with new fracking technology made a great impact on US energy (Islam, 2014). The year 2014 is marked with strong production in the United States and Russia that caused oil prices to crash from July to December. This led OPEC to the decisions to maintain production, which further damages the market heading into 2015. The year 2015 started off with the death of King Abdullah—an event many saw as a potential trigger for instability. However, the instability was not as much in power struggle but more as who assumed power. Initially, Mohamed Bin Salman became the Minister of Defense, whose first act was to orchestrate the Yemen war, which later triggered the most devastating “the worst man-made humanitarian crisis of our time,” as recounted by UN officials (Carey, 2018). This political turmoil, however, was overshadowed by the fact that on July 22 of this year, US output reached its highest level in more than 100 years. This is the time, prices hovered near $50 a barrel.

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FIGURE 2.32

2. Petroleum in the big picture

Oil prices in history since Second World War until 2018. Source: From Islam et al. (2018a).

In this context, it is important to look at the past to see the factors that shape oil prices. McGuire (2015) listed top 25 events that shaped the oil market since the first commercial trading of oil commenced in mid-1800s. These events are as follows: 1. Event (A), 1862
65. The American Civil War is in full swing, leading to crude oil demand skyrocketing due to its increasing use for lamps and medicinal purposes. This is the period petroleum began to replace heavily taxed and more expensive whale oil, another illuminant with similar qualities. This is the beginning of a culture of introducing tax to obstruct natural economy. 2. Event (B), 1865
90. Prices saw boom and bust over the next 25 years due to fluctuations in US drilling. By 1877, John D. Rockefeller’s Standard Oil Company controls more than 95% of all oil refineries in the country. This is the period refining became integral part of oil production. 3. Event (C), 1890
92. The United States entered its worst recession to date, causing oil prices to plummet. The period is marked by the excessive financing of railroads, which results in a series of bank failures. Unemployment ranged from 17% to 19%. 4. Event (D), 1891
94. The Titusville oil fields that gave birth to the US oil industry start to decline. This sets the stage for higher prices in 1895.

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5. Event (E), 1894. An international cholera outbreak drew back oil production throughout Europe, contributing to the 1895 spike. 6. Event (F), 1920. The widespread adoption of the automobile drastically raised oil consumption before one of the worst events in world history sent prices to record lows. 7. Event (G), 1931. The onset of the Great Depression reduced demand and sent prices sinking to $0.87 a barrel (roughly $12 a barrel today). 8. Event (H), 1947. Increased spending on advertising after the war lead to a huge boost in nationwide automobile sales. The automotive boom also caused gasoline shortages in many US states. 9. Event (I), 1956
57. Global prices remained steady due to two equalizing events. The blocked-off Suez Canal from the Suez Crisis took 10% of the world’s oil off the market, while soaring production outside of the Middle East made up for the absence of a major oil passageway. 10. Event (J), 1972. Total US production peaked near an average of 9 million barrels a day. 11. Event (K), 1973
74. During the Yom Kippur War, the Organization of Arab Petroleum Exporting Countries, which included Egypt and Syria, imposed an oil embargo against countries supporting Israel. By the end of the embargo in March 1974, oil prices had increased from $3 a barrel ($14 a barrel today) to $12 ($58 today). 12. Event (L), 1978
79. Iran dramatically cut production and exported during the country’s Islamic revolution. 13. Event (M), 1980. The Iran
Iraq War further decreased exports from the Middle Eastern region. 14. Event (N), 1980s. A worldwide supply glut sets in, sending prices from over $35 a barrel (about $100 today) down to $12 (about $28). The former USSR. and United States were the top two producers in the world by 1985, respectively producing 11.9 million and 11.2 million barrels per day. 15. Event (O), 1986. Saudi Arabia decides to regain its share of the global oil market by increasing production in the face of crashing prices. The OPEC leader went from 3.8 million barrels a day in 1985 to more than 10 million barrels a day in 1986. 16. Event (P), 1988. The Iran
Iraq War ended in August, allowing both countries to start ramping up production. 17. Event (Q), 1990. Iraq invaded Kuwait after Saddam Hussein accuses Kuwait of stealing Iraq’s market share. The conflict involved Iraqi forces setting fire to up to 700 Kuwaiti oil wells. Kuwait cut exports until 1994 as a result. 18. Event (R), 1999. Thailand, Indonesia, and South Korea recovered from the 1997 financial crisis caused by the collapse of Thailand’s baht currency. Demand started to soar in the region. 19. Event (S), Early 2000s. Prices started to gain momentum due to growing US and world economies. They headed toward their highest level since 1981. 20. Event (T), 2001
03. The September 11 attacks and the invasion of Iraq raised concerns about the stability of the Middle East’s production. 21. Event (U), Mid-2000s. The combination of declining production and surging Asian demand send prices to record highs. 22. Event (V), 2008. The global financial crisis causes a bubble-bursting sell-off. Prices plummeted 78.1% from July to December.

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23. Event (W), 2011. Riots and protests from the Arab Spring wash over the Middle East. The Libyan civil war disrupts the region’s output. 24. Event (X), 2014. Strong production in the United States and Russia caused prices to crash from July to December. OPEC’s November decision to maintain production further damages the market heading into 2015. 25. Event (Y), 2015. US output reached its highest level in more than 100 years. Prices hover near $50 a barrel as of July 22. Fig. 2.34 shows the oil price for the period of 2012 through early 2021. Most notably, this covers the Trump era. President Trump’s energy policy was radically different from those of previous presidents and was a hallmark of success (Islam et al., 2018). However, like every other policy, Trump received little support from the media or the financial establishment. As early as 2017, it was noticeable that Trump was not going to get any support to receive credit for the economic boom, resulting from economic policies (Blackmon, 2017). Within months, however, Trump Administration implemented many policy changes, each of which turned out to be very productive. The most prominent move was Trump’s June 1 announcement that the United States would withdraw from the Paris climate accord. Environmental Protection Agency (EPA), on the other hand, dismantled President Barack Obama’s Clean Power Plan, a signature policy aimed at reducing greenhouse-gas emissions. The science behind the Clean Power Plan assumes that carbon is inherently unsustainable whereas noncarbon methods are sustainable. In June, following a February executive order from Trump, the EPA began the process of rescinding the 2015 Waters of the United States rule, which aimed at protecting smaller bodies of water and streams in the same way that larger ones had been. In December, in the closing weeks of his administration, Obama banned drilling in the Arctic and parts of the Atlantic Ocean; the Trump administration promptly set about undoing that ban, along with restarting the Keystone XL and Dakota Access pipeline projects. Although this ban has been halted by one of President Biden’s some dozen executive orders of the first day, 4 years of Trump era enjoyed the deregulation process and brought about historic achievements in both energy and environment. The energy policy, which leaned on oil and gas, along with massive tax cut laid the foundation of an economy that was parallel to none (Islam et al., 2018). Overall, it involves more oil and gas production and less environmental regulation (Yglesias, 2019). This has created unprecedented energy independence while simultaneously reducing CO2 emission. During this period, both crude oil price and gold price rose steadily with similar slope (Figs. 2.33 and 2.34). There is, however, a time that US oil prices turned negative for the first time on record shortly after the onset of Coronavirus pandemic. The price of US crude oil crashed from $18 a barrel to 2 $38 in a matter of hours, as rising stockpiles of crude threatened to overwhelm storage facilities and forced oil producers to pay buyers to take the barrels they could not store. This market crash was due to the impact of the coronavirus outbreak on oil demand as the global economy slumped due to lockdown measures. However, within a day prices rebounded above zero, with the US benchmark West Texas Intermediate (WTI) for May changing hands at $1.10 a barrel after closing at 2 $37.63 in New York. Oil producers have continued to pump near-record levels of crude into the global market even as analysts warned that the impact of the coronavirus outbreak would drive oil demand to its lowest levels since 1995. The emergence of negative oil prices is expected to

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FIGURE 2.33 Oil price in recent years. Source: From Trading economics (2021). https://tradingeconomics.com/commodity/crude-oil.

FIGURE 2.34 Gold price since 1970. Source: From Goldprice.org (2021). Gold Price History, https://goldprice.org/ gold-price-history.html.

prompt some oil companies to hasten the shutdown of their rigs and oil wells to avoid plunging deeper into debt or bankruptcy. The price collapse was meant to be a blow to US President Donald Trump who took credit for brokering a historic deal between the OPEC oil cartel and the world’s largest oil producing nations to limit the flood of oil production into the market. The pact to cut between 10 million and 20 million barrels of oil from the market from the following month was dismissed by many within the market as “too little, too late” to avoid a market crash. However, it turned out President Trump was correct in calling it a “short-term problem.” He said the US was filling up its strategic reserves: “If we could buy it for nothing, we’re gonna take everything we can get.” Brent crude

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reached highs of almost $69 a barrel in January before plummeting to less than $23 a barrel at the end of March. Many market experts predict the price of Brent will remain below $50 a barrel during 2020. None of these predictions have been true.

2.5.1 Environmental impact The unprecedented energy boom has been accompanied with environmental gains. Fig. 2.35 shows a steady decline in CO2 emissions during 1975 through 2019. The trend during the Trump era continued through 2020. While 2020 decline is associated with COVID-19 measures, the decline in fact correlates with the trend that began in 2015. This period is the one when the United States gained energy independence. Trading economics, 2021, https://tradingeconomics.com/commodity/crude-oil. In 2019, around 5.13 billion metric tons of CO2 emissions were produced from energy consumption in the United States. In 2018, around 36.6 billion metric tons of carbon dioxide were emitted globally. The year 1997 marked the birth of the Kyoto Protocol. That year, global energy-related CO2 emissions stood at around 24.4 billion metric tons. Despite numerous assurances by policymakers to undertake efforts to reduce pollution, this figure increased to more than 36 billion metric tons of carbon dioxide in 2017. North America and the Asia Pacific regions are presently the biggest producers of carbon dioxide emissions as a result of a growing thirst for energy derived from fossil fuels such as oil, natural gas, and coal. China is currently the most polluting country in the world, with a 27.5% share of global CO2 emissions in 2018. A comparative analysis between CO2 levels in 1993 and those in 2003 shows that emission levels in China have more than tripled in a span of 10 years. According to a recent forecast, energy-related global CO2 emissions from the consumption of coal, natural gas, and liquid fuels are set to rise to unprecedented levels through 2040, while US CO2 emissions produced by the use of natural gas are set to grow from 1.68 billion metric tons of CO2 equivalent in 2019 to 1.97 billion metric tons in 2050. In 2014, in Lima, Peru, negotiations were held regarding a post-Kyoto legal framework forcing major polluters, including China, India, and the United States, to pay for CO2 FIGURE 2.35 Carbon dioxide emissions from energy consumption in the United States from 1975 to 2019 (in million metric tons of carbon dioxide). Source: From Statistia (2021). https://www.statista. com/statistics/183943/us-carbon-dioxide-emissions-from-1999/#:B:text 5 The%20statistic% 20shows%20the%20total,carbon%20dioxide% 20was%20emitted%20globally.

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emissions. Although most countries refused to ratify this latter treaty, there has been a worldwide commitment toward so-called “green energy.” Global renewable energy consumption soared from 44.4 million metric tons of oil equivalent in 1998 to 561 million metric tons of oil equivalent in 2018. International investments in renewable energy sources increased six-fold, as the world has invested more than 288 billion US dollars in alternative energy sources and technologies as of 2018.

2.6 Key events and future outlook of oil and gas 2.6.1 US energy outlook The dramatic increase in oil and gas production in the United States got its boost from the use of fracking in unconventional oil and gas fields (Islam, 2014). The political event that led to the unleashing of this production boom was greatly facilitated by the lifting, in November 2015, of the prohibition to export crude oil, which had been in place since 1973. Such a major political decision came at a time when US domestic refineries are reaching their maximum levels of shale oil processing capacity and oil storage in the United States is at a historical high, making crude oil exports a logical move. After the Trump presidency, US crude oil production continued at the fastest rate on record as the increase in prices during the new US regime boosted drilling and completion activities and oil companies employ more horsepower to fracture larger wells (Kemp, 2018). Crude and condensates output hit a record 11.35 million barrels per day in August, up from 10.93 million bpd in July, 2018 (EIA Report, 2018). Crude output has increased by more than 2 million barrels per day over 2018, an absolute increase that is unparalleled in the history of the US oil industry (Kemp, 2018). Even in percentage terms, output was up in 2018 by nearly 25% over the year, the fastest increase since the 1950s (excluding the recovery from hurricanes). This rate indeed is faster than at the height of the last drilling and fracking boom before prices slumped in the second half of 2014. Most of the increase is coming from onshore shale fields, where output has risen by more than 1.9 million bpd over the last year, with a smaller contribution from the Gulf of Mexico, where output is up 200,000 bpd. This increase has been for both oil and natural gas. Fig. 2.36 shows how both oil and gas from shale formations have increased for each region. In the first nine months of 2018, the number of wells drilled in the United States was up by 26% while well completions were up by 24% (EIA, 2018). This surge in US domestic output coupled with increased production from Russia and Saudi Arabia and a number of other OPEC countries has pushed oil prices lower (Fig. 2.37). Figs. 2.38 and 2.39 show natural gas production and future projections of unconventional gas production. Fig. 2.38 shows the United States once became a natural gas net exporter, starting from 2016 (Fig. 2.40). In the United States, crude oil imports have decreased steadily in recent years as US crude oil production has increased. After averaging a record high of 10.1 million b/d in 2005, crude oil imports fell by 2.8 million b/d to an average of 7.3 million b/d in 2014. Since then, crude oil imports have increased slightly, averaging 7.7 million b/d in 2018.

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FIGURE 2.36 Yearly change in unconventional oil and gas. Source: From EIA, 2018. China surpassed the United States as the world’s largest crude oil importer in 2017, December 31, 2018.

FIGURE 2.37 Dry shale gas production since 2006.

U.S. dry shale gas production billion cubic feet per day 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

Marcellus (PA, WV, OH & NY) Permian (TX & NM) Utica (OH, PA & WV) Haynesville (LA & TX) Eagle Ford (TX) Barnett (TX) Woodford (OK) Bakken (ND & MT) Niobrara-Codell (CO & WY) Mississippian (OK) Fayetteville (AR) Rest of US ‘shale’

2006

2008

2010

2012

2014

2016

2018

2020

Not all crude oil is of the same quality. Most of the reduction in US imports was of light, sweet crude oil, as those barrels were replaced by domestic production of a similar quality. US crude oil exports have also increased as domestic production has risen. US crude oil exports have set annual record highs in each year since 2014, most recently averaging 2.0 million b/d in 2018. At the same time, US refinery runs have been setting record highs. The increase in refinery output of petroleum products has outpaced the increase in US consumption of petroleum products such as distillate fuel oil, gasoline, and propane, leading to an increase in exports. Considering the overall age of refineries and declining productivity, this is a remarkable feat. Total US petroleum product exports averaged a record 5.6 million b/d in 2018. Distillate and gasoline exports have increased, particularly to countries in the Western Hemisphere. Propane exports have also increased, mostly to Asian markets.

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FIGURE 2.38 Future projection of dry natural gas production (EIA, 2020).

EIA expects these trends to continue over the next several years. In its March ShortTerm Energy Outlook, EIA forecasts that the United States will become a net exporter of crude oil and petroleum products on a monthly basis later this year and on an annual basis in 2020.

2.6.2 China’s economic slowdown Since initiating market reforms in 1978, China has shifted from a centrally planned to a more market-based economy and has experienced rapid economic and social development. GDP growth has averaged nearly 10% a year—the fastest sustained expansion by a major economy in history (World Bank, 2019). China reached all the Millennium Development Goals (MDGs) by 2015 and made a major contribution to the achievement of the MDGs globally. However, China’s GDP growth has gradually slowed since 2012, as needed for a transition to more balanced and sustainable growth. The current lower rate of growth of China’s economy can be dismissed as just a transitional phase of a normal economic cycle. That means that after decades of double-digit growth, it is only normal that a period of slower growth ensues. However, the concern is that China’s economy may not just be slowing down temporarily but has instead entered a new and prolonged period of weak growth. The GDP has been declining steadily since the record high in 2007. In 2015, China’s growth was the weakest of the previous 25 years, accompanied by a collapse of the stock market and a significant devaluation. In January of

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FIGURE 2.39

Natural gas production, consumption, and net import (EIA, 2020).

FIGURE 2.40

Net oil imports of United States. Source: From EIA, 2020. Rankings about energy in the World, Energy Information Administration (EIA). https://www.eia.gov/international/overview/world#.

International—U.S. YhONEDkZEkA.

2016, some $110 billion left the country, while over $600 billion of capital flight took place during 2015. The most troubling sign, however, is the skyrocketing growth of the national debt, which has tripled since 2007. Nevertheless, China has been the largest

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single contributor to world growth since the global financial crisis of 2008. The impact of China’s level of economic activity on global energy demand (and prices) is well known. An economic downturn in China means lower prices for all the commodities that the Asian giant voraciously imports and oil is no exception. In response, the government has stressed its intention to move the economy away from its reliance on exports as a source of growth to the expansion of the domestic market and from massive infrastructure investments and industrial development to the stimulus of a larger and stronger service sector. All these are political decisions that will profoundly change the way China produces and consumes energy.

2.6.3 The Middle East crisis Bloomberg reported that “about 2.6 million barrels a day are being kept from the market by conflict and sanctions in the region, more than five times the average from 2000 to 2010” (Naı´m, 2019). The IEA energy outlook for 2016 reports oil production disruptions averaging 3.2 million barrels per day over the last 2 years, mostly due to political instability in Iraq, Libya, South Sudan, and Syria. This significant supply imbalance has been partially compensated by new Iranian exports, which have doubled since last year, reaching 2.1 million barrels per day in May. Such an increase is the result of the lifting of sanctions against Iran by western powers, following the nuclear deal reached in July 2015. However, in April, 2019, the United States announced that the Iran sanction waiver would end, creating a surge in the oil price (Elliott, 2019). The instability in the Middle East has disrupted the global oil supply and has contributed to fragment and weaken OPEC, leading one of Vladimir Putin’s main collaborators, Igor Sechin, to say that “OPEC has practically stopped existing as a united organization.” Meanwhile, Libya, Syria Egypt, and the Eastern Mediterranean are all hotspots rife with instability and hydrocarbons. The latest crisis has been the civil war in Libya (Lee, 2019). Fig. 2.41 shows how radical the impact of Libya civil war has been on the oil price. In the Middle East, politics far outweighs technology in defining its weight in the world of energy.

2.6.4 Russia’s expansionism and sanctions Russia’s 2014 annexation of Crimea triggered economic sanctions by the EU and the United States. Some of these sanctions directly affect the Russian energy sector and its ability to continue to be the foremost supplier of natural gas to Europe. The sanctions include the freezing of exports to Russia of energy-related equipment and technology and the banning of the supply to Russian oil and gas companies of services such as drilling, well testing, and completion services. Equally important has been the impact on the natural gas market (discussed in a later section). Many observers predicted that the international coalition that supported the sanctions would quickly fragment, that the sanctions would be watered down or that they would be short-lived and ineffectual. None of these predictions has come to pass. Instead, the Kremlin’s decision to annex Crimea and destabilize Ukraine has resulted in major upheavals in Russia’s oil and gas industry and

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FIGURE 2.41 Oil price in recent years. Source: From Lee (2019). Any damage to exports will tighten global supplies already constrained by chaos Venezuela and sanctions on Iran, Bloomberg.

an unexpected opening for US gas exporters to European markets. Recently, this political event has entered a new phase when Russian invaded Ukraine in February, 2022, as discussed in previous sections.

2.6.5 The implosion of Venezuela and Brazil Both Venezuela and Brazil had been in the crosshairs of the United States. However, after the election of a right-wing president in Brazil, Venezuela has been the sole target of US regime-change politics. The allegations of mismanagement, lack of investment, and massive corruption in Venezuela’s state oil company created a crisis that culminated in creating an alternate government, calling President Maduro illegitimate. Venezuela—the country with largest oil reserve has seen a massive loss in production and exports. In both cases, technology had nothing to do with their downfall. It was all about politics, as summed up by sanctioning of Venezuelan national oil company, Petro´leos de Venezuela, S.A. (PDVSA), and freezing of its asset in the United States. The most recent political events and their effect on oil prices are shown in Fig. 2.42. This figure shows discounts offered on Dubai crude marker. The effects of events in Saudi Arabia, Iran, Canada, and Venezuela all have effects on the market price. In terms of future, Iraq is scheduled to become a major player. International Energy Agency declared that Iraq would be the third-biggest provider of new oil supplies over the next decade (Smith, 2019). However, the growth rate is slower than that seen earlier this decade as Iraq faces competition for foreign investment and expertise and struggles to inject enough water to maintain pressure at oil reservoirs. The OPEC member will raise output to almost 6 million barrels a day by 2030, overtaking Canada as the world’s fourth-largest producer, as it continues to rehabilitate an oil industry ravaged by decades of conflict and sanctions. Water supplies are one of the industry’s most acute needs, because relatively low recovery rates mean that Iraqi oil fields rely on the injection of liquids to sustain reservoir pressure. Demand for water in Iraq’s oil sector will climb by 60% to more than 8 million barrels a day by 2030, the IEA estimated (Smith, 2019). Fig. 2.43 shows the short-term history and outlook of oil prices.

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FIGURE 2.42 Discounts and correlation with political events. Source: From Cheong (2015). OPEC Brings Oil Price War Home in Pursuit of Asia’s Cash, Bloomberg.

95% NYMEX Futures price Confidence interval upper bound

120 100

West Texas Intermediate (WTI) spot price

80

STEO forecast NYMEX futures price

60 40 20 0 2014 2015

2016

2017

2018

2019

2020

FIGURE 2.43 Shortterm energy outlook. Source: From EIA (2019a). Energy Outlook, https://www.eia.gov/ outlooks/steo/.

95% NYMEX futures price confidence interval lower bound

Brent crude oil spot prices averaged $66 per barrel (b) in March, up$2/b from February 2019. Brent prices for the first-quarter of 2019 averaged $63/b, which is $4/b lower than the same period in 2018. Despite lower crude oil prices than the year before, Brent prices in March were $9/b higher than in December 2018, marking the largest December-toMarch price increase since December 2011
March 2012. EIA forecasts Brent spot prices will average $65/b in 2019 and $62/b in 2020, compared with an average of $71/b in 2018. EIA expects that WTI crude oil prices will average $8/b lower than Brent prices in the first half of 2019 before the discount gradually falls to $4/b in late 2019 and through 2020. EIA (2019) estimates that US crude oil production averaged 12.1 million barrels per day (b/d) in March, up0.3 million b/d from the February average. EIA forecasts that US crude oil production will average 12.4 million b/d in 2019 and 13.1 million b/d in 2020, with most of the growth coming from the Permian region of Texas and New Mexico.

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For the 2019 summer driving season that runs from April through September, EIA forecasts that US regular gasoline retail prices will average $2.76 per gallon (gal), down from an average of $2.85/gal last summer. EIA’s forecast is discussed in its Summer Fuels Outlook. The lower forecast gasoline prices primarily reflect EIA’s expectation of lower crude oil prices in 2019. For all of 2019, EIA expects US regular gasoline retail prices to average $2.60/gal and gasoline retail prices for all grades to average $2.71/gal, which would result in the average US household spending about $100 (4%) less on motor fuel in 2019 compared with 2018. In many regards, gas prices have been influenced by political factors, but some aspects of natural gas are unique. Fig. 2.44 shows gas prices over last few decades. Fig. 2.45 adds older history of gas price. This figure shows that stable gas prices were maintained throughout the few decades after the second world war. As can be seen in Fig. 2.45, from 1949 to 1978, wellhead prices averaged $0.21 per thousand cubic feet (mcf). During that period, gas prices were regulated. Although phased deregulation began with the passage of the Natural Gas Policy Act of 1978, prices began to rise in the mid-1970s, a period of turmoil in international energy markets that saw a sharp increase in crude oil prices (triggered by the 1973 Arab oil embargo). This rise continued until 1984 at $2.66 per mcf (nominal). Prices subsequently retreated modestly and then remained fairly stable for several years. From 1986 to 1999, natural gas prices averaged $1.87 per mcf. Following the 9/11 terror attack and following recession, natural gas prices began to rise, keeping pace with the oil price. By 2004,

FIGURE 2.44 Gas price (in $/million BTU). Source: From EIA, 2018. China surpassed the United States as the world’s largest crude oil importer in 2017, December 31, 2018. FIGURE 2.45 Gas price (in $/1000 Cuft). Source: From EIA (2017). International Energy Outlook, https://www.eia.gov/outlooks/ ieo/pdf/0484(2017).pdf.

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gas prices in both real and nominal dollars were at record-high levels. The late 2005 rise in gas price was due to severe weather issues related to Hurricane Katrina (in Louisiana) and Hurricane Rita (in Texas
Louisiana border) that damaged Gulf Coast’s production, refining, and distribution facilities. Other events were due to international events triggered by Russia (Islam, 2014). Even before the former USSR broke down, gas export from Russia had been declining. Even though such decline is often correlated with political events and US hegemony, the fact remains that the so-called “gas war” had to break out in order to restore values of natural gas to the level comparable to crude oil or petroleum liquids. Even though Gazprom was privatized in 2005, the Russian government has held a controlling share in Gazprom. The earliest sign of restoration of natural gas price to an equitable value was in place when on October 2, 2008, the Ukrainian Prime Minister Julia Timoshenko and the then Russian Prime Minister Vladimir Putin had agreed in a memorandum on the Ukraine raising the gas price to world market standards within the next 3 years. Previous to that, Russia had delivered gas to the Ukraine far below world market prices until the end of at the end of 2008, the existing contract between the Russian Gazprom and the Ukrainian gas corporations expired both gas corporations are understate control. A new contract about a new gas price in terms of the October 2008 memorandum and valid from January 1, 2009, was prevented by the Ukraine, although Russia had made an offer to deliver the gas at a price of US$ 250/1000 m3, which is less than the current world market price. Thus, Gazprom stopped its gas deliveries to the Ukraine on January 1, 2009. And this led to Ukraine unlawfully tapping the transit pipelines running through the Ukraine to other European states. Russia reacted by discontinuing the gas transfer across the Ukraine, completely. What followed after this turmoil is a series of political events that culminated in the annexation of Crimea by Russia. On November 25, 2015, Gazprom halted its exports of Russian natural gas to Ukraine. According to the Ukrainian government, they had stopped buying from Gazprom because Ukraine could buy natural gas cheaper from other suppliers. According to Gazprom, it had halted deliveries because Ukraine had not paid them for the next delivery. Since then, Ukraine has been able to fulfill its gas supply needs solely from EU states. In 2018, the Arbitration Institute of the Stockholm Chamber of Commerce ordered that Ukraine’s Naftogaz should import 5 bcm of gas annually from Russia, as required under its 2009 contract with Russia’s Gazprom. These events ended up making little impact on the natural gas price. In recent years (Fig. 2.46), natural gas consumption rose by 96 bcm, or 3%, the fastest since 2010 (BP, 2019). Consumption growth was driven by China (31 bcm), the Middle East (28 bcm), and Europe (26 bcm). Consumption in the United States fell by 1.2%, or 11 bcm. Meanwhile, global natural gas production increased by 131 bcm, or 4%, almost double the 10-year average growth rate. In 2018, Russian growth was the largest at 46 bcm, followed by Iran (2 bcm). With the Iran sanction looming, it is likely that Russia will become the biggest beneficiary of the energy crisis. In the short term, the Henry Hub natural gas spot price averaged $2.95/million British thermal units (MMBtu) in March, up 26 cents/MMBtu from February. Prices increased as a result of colder-than-normal temperatures across much of the United States, which increased the use of natural gas for space heating. EIA (2019) expects strong growth in US natural gas production to put downward pressure on prices in 2019 and in 2020. EIA

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FIGURE 2.46

$/million BTU gas price. Source: From EIA (2019a). Energy Outlook, https://www.eia.gov/outlooks/steo/.

FIGURE 2.47

US energy outlook (EIA, 2018).

expects that Henry Hub natural gas spot prices will average $2.82/MMBtu in 2019, down 33 cents/MMBtu from 2018. The forecasted 2020 Henry Hub spot price is $2.77/MMBtu. EIA (2019) forecasts that dry natural gas production will average 91.0 billion cubic feet per day (Bcf/d) in 2019, up 7.6 Bcf/d from 2018. EIA expects natural gas production will continue to grow in 2020 to an average of 92.5 Bcf/d. EIA estimates that natural gas inventories ended March at 1.2 trillion cubic feet (Tcf), which would be 17% lower than levels from a year earlier and 30% lower than the 5-year (2014
2018) average. EIA forecasts that natural gas storage injections will outpace the previous 5-year average during the April-through-October injection season and that inventories will reach 3.7 Tcf at the end of October, which would be 13% higher than October 2018 levels but 1% lower than the 5-year average. The impact of political events is rarely included in the EIA forecast, whereas the spot price is primarily dictated by political events. Fig. 2.47 shows that both oil and gas maintain a steady increase in world demand. Only coal went through a sharper rise during 2003 through 2005, due to excessive growth in Chinese energy consumption. Overall, renewables remained insignificant until many

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FIGURE 2.48 Long-term projections based on past performance in the United States, and y-axis represents quadrillion British thermal units. Source: From EIA, 2019. International Energy Outlook, https:// www.eia.gov/outlooks/ieo/pdf/ieo2019.pdf.

government-funded projects were initiated during the Obama presidency as well as in Europe. As Islam and Khan (2019) pointed out this was more of a policy choice rather than a scientific need. In terms of project, natural gas shows the highest growth in the 30-year projection. In fact, other than natural gas, only renewable and liquid biofuels show a modest increase, while others drop or remain constant. Natural gas plays even more intense role when it comes to electrical power usage (Fig. 2.48).

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3 Fundamentals of processing 3.1 Introduction Both oil and gas processing involves extracting homogenous components from natural state. Typical oil well fluids are a mixture of oil, gas, and saline water. For oil, the initial separation involves separating oil from water and gas. Depending on the conditions, this separation can be carried out in several stages. This crude oil can be transported in pipelines and exported in tankers in this form. The economic benefit of crude oil is an order of magnitude less than that associated with refined crude oil. Crude oil refining involves use of distillation to break down crude oil into numerous usable and valueadded products (Fig. 3.1). In this process, many chemicals are added to facilitate the distillation. At a later stage, more chemicals are added to render the waste into useable polymers, including plastic. Gas processing, on the other hand, is principally about removing water, CO2, and sulfur contents, the presence of which reduces the heating value and can cause corrosion.

3.1.1 Background Refining oil to make it more amenable to burning is an old technology. For instance, in terms of refining petroleum products, there is evidence that even during medieval era, refining techniques were present. However, in those days, refining was not done in an unsustainable manner (Islam et al., 2010). There is evidence that both distillation and expression were common during the medieval era. In the perfume industry, as early as during early Islamic era (7th century onward), distillation in the form of hydrodistillation and production of absolute, mainly through Enfleurage and fermentation was common (Rahman and Islam, 2018). Some reports show that the refining practice is even older than medieval era. The recent discovery of a 5000-year-old earthenware distillation apparatus, used for steam distillation tells us that our ancestors were well versed on developing sustainable technologies (Islam, 2020). Khan and Islam (2016) demonstrated how an earthenware distillation apparatus is sustainable. The ancient and middle age practices were mainly focused on medicinal applications. It was the case in ancient Orient and ancient Greece and Rome, as well as the Americas the oils used for medicinal purposes.

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FIGURE 3.1 Crude oil broken down into useful and value-added products.

TABLE 3.1 Classification of the procedures use by Al-Razi in book of secrets. Type of Procedure

Purpose

Count Percent Example

Primary

Produces a substance that transforms metals into gold or silver

175

45

Sublimation of mercury

Intermediate

Prepares materials required for primary procedures

127

33

Calcination of silver through burning

Reagent

Produces a chemical used in other procedures

51

13

Liquids that dissolve or create colors

Preparation

Instructions for a method used in other procedures

36

9

Mixing through pulverizing and roasting

389

100

Total From Islam (2020).

During the 5th century AD, the famed writer, Zosimus of Panopolis, refers to the distilling of a divine water and panacea. Throughout the early Middle Ages and beyond, a basic form of distillation was known and was used primarily to prepare floral waters or distilled aromatic waters. These appear to have been used in perfumery, as digestive tonics, in cooking, and for trading. Over 1000 years ago, Al-R¯az¯ı (865
923), a Persian Muslim alchemist, wrote a book titled: Kitab ¯ al-Asrar ¯ (Book of Secrets), in which he outlined a series of refining and material processing technologies. Al-R¯az¯ı developed a perfectly functioning distillation process. In this distillation process, he used naturally occurring chemicals. His stockroom was enriched with products of Persian mining and manufacturing, even with sal ammoniac, a Chinese discovery. These were all additives that he was using similar to the way catalysts are used today. His approach was fitting for his time, but way ahead of today’s concept of technology development. He avoided, the “intellectual approach” (what has become known as mechanical approach ever since Newtonian era or New Science) in favor of causal or essential approach (what Khan and Islam, 2016, called the “science of intangibles”). Table 3.1 lists that the 389 procedures by Al-R¯az¯ı can be divided into four basic types: primary, intermediate, reagent, and preparation methods. The 175 “primary” procedures involve transformation of metals into gold or silver. It is worth noting here that bulk of Newton’s unpublished work also involved transformation of metals into gold (Zatzman and Islam, 2007). The 127 preparatory procedures involve softening and calcination. Today, equivalent processes are called denaturing, in which the natural features of materials are rendered artificial. Al-R¯az¯ı then adds 51 procedures for reagent preparations.

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The reagents are solvents and tinctures, which usually contain a trace amount of heavy metals. It is similar to what is used today except that Al-R¯az¯ı used natural sources. Table 2.1 further lists 36 instructions for commonly needed processes such as mixing or dissolving. The procedure types include sublimation, calcination, softening whereas major sources are all natural (such as quicksilver, sulfur, metals, and stones). The calcination, sublimation, and calcination themselves are also done through natural processes. The dominant theme was all source materials that are derived from plants, animals, and minerals and used in their natural state. The knowledge of seven alchemical procedures and techniques involved: sublimation and condensation of mercury, precipitation of sulfur, and arsenic calcination of minerals (gold, silver, copper, lead, and iron), salts, glass, talc, shells, and waxing. In addition, the source of heat was fire. Al-R¯az¯ı gave methods and procedures of coloring a silver object to imitate gold (gold leafing) and the reverse technique of removing its color back to silver. Also described was gilding and silvering of other metals (alum, calcium salts, iron, copper, and tutty, all being processed in a furnace with real fire), as well as how colors will last for years without tarnishing or changing. Al-R¯az¯ı classified naturally occurring earthly minerals into six divisions (Rashed, 2019): ¯ , which is best described in ¯ , the plural of the Arabic word Ruh I. Four spirits (Al-Arwah ˙ ˙ the Qur’an as an order of Allah): 1. 2. 3. 4.

Mercury. Sal ammoniac, NH4Cl. Sulfur. Arsenic sulfide (orpiment, As2S3 and realgar, As4S4 or AsS).

Even though this classification has been often referred to as “ghosts that roam around the earth,” this translation is ill-conceived and defies Qur’anic logic. Correct meaning is these materials are the source materials as in essence. In our previous work, we have called it the “intangible” (Islam et al., 2010, 2015; Khan and Islam, 2012; Zatzman and Islam, 2007). The above list is meaningful. Each of these materials bears some significance in terms of sustainability and human health. In today’s society, mercury is known to be a toxic material with adverse effects on the body and unanimously portrayed as a toxic chemical with long-term implication, it is one of those rare metals that had time-honored applications even in the ancient society (Iqbal and Asmat, 2012). This unique heavy metal, which is less toxic in its elemental form than in its compound form, has enjoyed both industrial and medicinal applications throughout history (Wong, 2001). Refining with artificial chemicals and energy sources is a recent phenomenon. Only this postindustrial revolution period saw wastage during the refining process, saving only the final product, that is, kerosene (Fig. 3.1). It started with the time, and petroleum golden era was in a nascent state. Captain Edwin L. Drake, a career railroad conductor who devised a way to drill a practical oil well, is usually credited to have drilled the first-ever oil well in Titusville, Pennsylvania in 1859. Curiously, initial “thirst” for oil was for seeking a replacement of natural oils (e.g., from whales) as a lubricating agent. Recall the need for such oil owing to a surge of mechanical devices in mid-1800s. Even if one discards the notion that petroleum was in use for thousands of years, there is credible evidence that the first well in modern age was drilled in Canada. Canadian, Charles Nelson Tripp, a foreman of a stove

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foundry, was the first in North America to have recovered commercial petroleum products. The drilling was completed in 1851 at Enniskillen Township, near Sarnia, in present-day Ontario, which was known as Canada West at that time. Soon after the “mysterious” “gum bed” was discovered, the first oil company was incorporated in Canada through a parliamentary charter. Unlike Captain Drake’s project, this particular project was a refining endeavor in order to extract fuel from bitumen. Tripp became the president of this company on December 18, 1854. The charter empowered the company to explore asphalt beds and oil and salt springs, and to manufacture oils, naphtha paints, burning fluids. Even though this company (International Mining and Manufacturing) was not a financial success, the petroleum products received an honorable mention for excellence at the Paris Universal Exhibition in 1855. Failure of the company can be attributed to several factors contributed to the downfall of the operation. Lack of roads in the area made the movement of machinery and equipment to the site extremely difficult. After every heavy rain, the area turned into a swamp and the gum beds made drainage extremely slow. This added to the difficulty of distributing finished products. It was at that time that need for processing petroleum products in order to make them more fluid surfaced. In 1855, James Miller Williams took over the business of refining petroleum in Lambton County from Charles Nelson Tripp. At that time, it was a small operation, with 150 gallons/ day asphalt production. Williams set out during a drought in September 1858 to dig a drinking water well down-slope from it but struck free oil instead, thereby becoming the first person to produce a commercial oil well in North America, one year before Edwin Drake. Also of significance is the fact that he set up Canada’s first refinery of crude oil to produce kerosene, based on the laboratory work of Abraham Gesner. Interestingly, Gesner was a medical doctor by training (from London) but took a special interest in geology. He is the one credited to have invented kerosene to take over the previous market, saturated with whale oil—a wholly natural product. It was this Gesner, who in 1850 created the Kerosene Gas Light Company and began installing lighting in the streets in Halifax and other cities. By 1854, he had expanded to the United States where he created the North American Kerosene Gas Light Company at Long Island, New York. Demand grew to where his company’s capacity to produce became a problem, but the discovery of petroleum, from which kerosene could be more easily produced, solved the supply problem. This was the first time in recorded history artificial processing technique was introduced in refining petroleum products. Gesner did not use the term “refined” but made fortune out of the sale of this artificial processing. In 1861, he published a book titled: A Practical Treatise on Coal, Petroleum and Other Distilled Oils, which became a standard reference in the field. As Gesner’s company was absorbed into the petroleum monopoly, Standard Oil, he returned to Halifax, where he was appointed a Professor of natural history at Dalhousie University. It is this university that was founded on pirated money while other pirates continued to be hanged by the Royal Navy at Point Pleasant Park’s Black Rock Beach as late as 1844.1

1

A cairn in front of its administration building actually describes the university’s origins two centuries ago from a fund created to launder the ill-gotten gains of an early 19th century war crime committed by the Royal Navy against a customs house in the US state of Maine several months after Anglo-American hostilities of the War of 1812 had officially concluded.

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The Sarnia Observer and Lambton Advertiser, quoting from the Woodstock Sentinel, published on page two on August 5, 1858: An important discovery has just been made in the Township of Enniskillen. A short time since, a party, in digging a well at the edge of the bed of Bitumen, struck upon a vein of oil, which combining with the earth forms the Bitumen.

Some historians challenge Canada’s claim to North America’s first oil field, arguing that Pennsylvania’s famous Drake Well was the continent’s first. But there is evidence to support Williams, not least of which is that the Drake well did not come into production until August 28, 1859. The controversial point might be that Williams found oil above bedrock while “Colonel” Edwin Drake’s well located oil within a bedrock reservoir. History is not clear as to when Williams abandoned his Oil Springs refinery and transferred his operations to Hamilton. However, he was certainly operating there by 1860. Historically, the ability of oil to flow freely has fascinated developers and at the same time ability of gas to leak and go out of control has intimidated them. Such fascination and intimidation continue today while nuclear electricity is considered to be benign while natural gas considered to be the source of global warming, all because it contains carbon—the very component nature needs for creating an organic product. Scientifically, however, the need for refining stems from the necessity of producing clean flame. Historically, Arabs were reportedly the first ones to use refined olive oil. They used exclusively natural chemicals in order to refine oil (Islam et al., 2010). We have seen in the previous sections, the onset of unsustainable technologies is marked by the introduction of electricity and other inventions of the plastic era. For its part, natural gas seeps in Ontario County, New York were first reported in 1669 by the French explorer, M. de La Salle, and a French missionary, M. de Galinee, who were shown the springs by local Native Americans. This is the debut of natural gas industry in North America. Subsequently, William Hart, a local gunsmith, drilled the first commercial natural gas well in the United States in 1821 in Fredonia, Chautauqua County. He drilled a 27-foot deep well in an effort to get a larger flow of gas from a surface seepage of natural gas. This was the first well intentionally drilled to obtain natural gas. Hart built a simple gas meter and piped the natural gas to an innkeeper on the stagecoach route from Buffalo to Cleveland. Because there was no pipeline network in place, this gas was almost invariably used to light streets at night. However, in late 1800s, electric lamps were beginning to be used for lighting streets. This led to gas producers scrambling for alternate market. Shallow natural gas wells were soon drilled throughout the Chautauqua County shale belt. This natural gas was transported to businesses and street lights in Fredonia at the cost of US$0.50 a year for each light (Islam, 2014). In the mean time, in mid-1800s, Robert Bunsen invented the “Bunsen burner” that helped produce artificial flame by controlling air inflow in an open flame. This was significant because it helped produce intense heat and control the flame at the same time. This led ways to develop usage of natural gas for both domestic and commercial use. The original Hart gas well produced until 1858 and supplied enough natural gas for a grist mill and for lighting in four shops. By the 1880s, natural gas was being piped to

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towns for lighting and heat, and to supply energy for the drilling of oil wells. Natural gas production from sandstone reservoirs in the Medina formation was discovered in 1883 in Erie County. Medina production was discovered in Chautauqua County in 1886. By the early years of the 20th century, Medina production was established in Cattaraugus, Genesee, and Ontario counties. Gas in commercial quantities was first produced from the Trenton limestone in Oswego County in 1889 and in Onondaga County in 1896. By the end of the 19th century, natural gas companies were developing longer intrastate pipelines and municipal natural gas distribution systems. The first gas storage facility in the United States was developed in 1916 in the depleted Zoar gas field south of Buffalo. By the late 1920s, declining production in New York’s shallow gas wells prompted gas companies to drill for deeper gas reservoirs in Allegany, Schuyler, and Steuben counties. The first commercial gas production from the Oriskany sandstone was established in 1930 in Schuyler County. By the 1940s, deeper gas discoveries could no longer keep pace with the decline in shallow gas supplies. Rapid depletion and overdrilling of deep gas pools prompted gas companies in western New York to sign long-term contracts to import gas from out of state. It took the construction of pipelines to bring natural gas to new markets. Although one of the first lengthy pipelines was built in 1891—it was 120 miles long and carried gas from fields in central Indiana to Chicago—there were very few pipelines built until after World War II in the 1940s. Similar to all other developments in modern Europe, World War II brought about changes that led to numerous inventions and technological breakthroughs in the area of petroleum production and processing. Improvements in metals, welding techniques, and pipe making during the War made pipeline construction more economically attractive. After World War II, the nation began building its pipeline network. Throughout the 1950s and 1960s, thousands of miles of pipeline were constructed throughout the United States. Today, the US pipeline network, laid end to end, would stretch to the moon and back twice. The phenomenon of pipelining is of significance. Because of this, there has been tremendous surge in the corrosion control industry. Onondaga reef fields were discovered by seismic prospecting in the late 1960s. Seven reef fields have been discovered to date in southern New York. Today, the Onondaga reef fields and many Oriskany fields are largely depleted and are being converted to gas storage fields. This state of depletion was achieved after a long production period and extensive hydraulic fracturing throughout 1970s and 1980s. These were considered to be tight gas sands. Recently, the same technology has made a comeback (Islam, 2014). The rapid development of New York’s current Trenton-Black River gas play is made possible by technological advances in three-dimensional (3D) seismic imaging, horizontal drilling, and well completion. The surge in domestic oil and gas production through “fracking” emerges from technologies popularized in the 1970s. However, 3D seismic or multilateral drilling technology was not in place at the time. Fig. 3.2 shows how natural gas production evolved in the state of New York throughout history. Unlike refining technology, which has a distinct past of using sustainable chemicals prior to industrial revolution, gas processing is entirely a modern phenomenon and does not have any tradition to use natural chemicals (Islam et al., 2010).

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FIGURE 3.2 Refining in 19th century involved discarding heavy components of the crude oil.

3.1.2 Chemicals used during refining Echemi.com lists the following chemicals that are used in a refining operation. 1. Halogenated hydrocarbons They include a. Chloromethane (CHCl3). b. Dichloromethane (CHCl2Cl). c. Trichloromethane (CHCl3). These chemicals can negatively affect human health and also impact environmental quality. They are considered to be carcinogenic as well as toxic, affecting several organ systems if exposure is sufficient. Toxicity ranges from mild effects such as drowsiness, slurred speech, or headaches to extreme reactions such as coma or death. Exposure can occur accidentally through industrial accidents or at home through improper storage or disposal of chemicals. 2. Sulfur compounds Sulfur compounds have two functions: a. They help remove sulfur from crude oil, thus making crude more marketable. b. They can be used as a cheap additive in gasoline to boost octane ratings without having to resort to expensive additives, such as butylated hydroxytoluene (BHT). A chemical called D-limonene is often used as an alternative if no sulfur is available because it has similar properties and acts as an octane booster. BHT is known to be toxic and can cause damage to liver, lung, and kidneys (Kahl, 1992). 3. Nitrogen compounds Some nitrogen compounds are used as foaming agents or catalysts during refining. Nitrogen is also used to make ammonia, a fertilizer, from atmospheric nitrogen and hydrogen. Ammonia is then used to make nitric acid, another important chemical for oil refineries and many other industries. In addition, ammonia can be converted into a solid called ammonium hydroxide, which is added to oil as it passes through pipelines. Adding ammonium hydroxide acts as a corrosion inhibitor so that the pipelines do not need extensive maintenance. Finally, hydrochloric acid is created by adding hydrogen gas and chlorine gas together at high temperatures; it is often referred to as muriatic acid.

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4. Oxygen compounds These chemicals used include a. Oxygen (O). b. Nitrous oxide (NO). c. Carbon dioxide (CO2), hydrochloric acid (HCl), and sulfuric acid (H2SO4). The H2SO4 is often used to help convert a portion of natural gas into synthetic crude oil, which itself can be used to make gasoline. All these chemicals add more problems to refinery’s environmental impact. Each of these processes have safety risks as well. 5. Carbon dioxide. It’s an invisible component of Earth’s atmosphere that humans have introduced into high concentrations through industrial processes, such as oil refining. While it has little effect on temperature, CO2 can affect global climate patterns such as rainfall, storm intensity, and wind currents around Earth. This is particularly the case because CO2 used is industrial CO2 (Islam and Khan, 2019). The process for removing carbon dioxide during crude oil production relies on breaking down hydrocarbons using a thermal heat source known as cracking at temperatures reaching approximately 1200 F (or 649 C). The reaction forces remaining molecules together until they recombine and separate into their base elements: hydrogen and carbon. 6. Catalysts Fig. 3.3 shows the modern petroleum refinery process. It contains many types of heterogeneous catalysts, such as fluid catalytic cracking (FCC) catalysts, hydrocracking catalysts, and hydrotreating catalysts. The composite and properties of three catalysts are listed in Table 3.2. FCC catalysts are used to improve the yield of higher octane gasoline from crude oil because heavy oil is more and more popular. Hydrotreating and hydrocracking catalysts are applied to improve fuel quality by saturating the olefin and removing the impurities in petroleum feedstocks. Hydrotreating and hydrocracking catalysts become more important due to more and more tightened environment protection. These active metal components all form a hazard to the environment and the ecosystem. This group of contaminants includes the minerals and toxic metals. Some of these contaminants like calcium and magnesium are naturally occurring. Others like copper and lead usually get into the water from pipes. Some of these contaminants such as lead and arsenic can be quite dangerous. However, these types of contaminants enter the water system via one certain, identifiable source, such as a pipe or a ditch. This type of contamination source includes municipal sewage systems and industrial and construction sites. 3.1.2.1 Arsenic Arsenic is notorious as a toxic element. Its toxicity, however, depends on the chemical (valency) and physical form of the compound, the route by which it enters the body, the dose and duration of exposure and several other biological parameters. It is recommended that, when water is found to contain arsenic at levels of 0.05 ppm, an attempt should be made to ascertain the valency and chemical forms of the element. Arsenic is commonly associated as an alloying additive with lead solder, lead shot, battery grids, cable sheaths,

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FIGURE 3.3 Layout of a typical high-conversion oil refinery. Source: From Hsu and Robinson (2006).

TABLE 3.2 Properties of petroleum refinery catalysts. Catalysts

Active metals

Supports

Reaction conditions

Function

Feed

FCC




Ultra stable Y, ZSM-5

T 5 450 C
550 C, P 5 0.1
0.3 MPa

Cracking, isomerization, aromatization

VGO, CGO, AR, VR

Hydrotreating catalyst

Ni
W; Ni
Mo; Co
Mo; Pt/Pd

T 5 300 C
450 C, Al2O3, Al2O3
SiO2 P 5 1.0
10.0 MPa

HDS, HDN, HDO, HDM and hydrogenation, saturation

Diesel, gasoline, kerosene, lubricant wax

Hydrocracking catalyst

Ni
Mo; Co
Mo; Ni
W

Y, β

Hydrogenation, cracking, and isomerization

AGO, VGO, CGO, DAO, HAGO

T 5 260 C
400 C, P 5 10.0
15.0 MPa

AGO, Atmospheric gas oil; AR, atmospheric residue; CGO, coker gas oil; DAO, deasphalted oil; HAGO, heavy atmospheric gas oil; VGO, vacuum gas oil; VR, vacuum residue.

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and boiler piping. Nowadays, most arsenic originates from paints or pharmaceuticals and is commonly found in sewage. The concentration of arsenic in seawater is around 0.002 ppm. The primary concerns are carcinogenicity and mutagenicity. 3.1.2.2 Silver Silver occurs naturally in elemental form and as various ores. It is also associated with lead, copper, and zinc ores. Because some metals such as lead and zinc are used in distribution systems and also because in some countries silver oxide is used to disinfect water supplies, silver levels in tap water may sometimes be elevated. The levels of silver in drinking water should not exceed 1 ppb. In industry, silver is used in the manufacture of silver nitrate, silver bromide and other photographic chemicals, water distillation equipment, mirrors, silver plating equipment, special batteries, table cutlery, jewelry, and dental medical and scientific equipment including amalgams. 3.1.2.3 Cadmium Cadmium is widely distributed in the Earth’s crust, but is particularly associated with zinc and copper and is produced commercially only as a by-product of zinc smelting. Cadmium shows no signs of being an essential trace element in biological processes; on the contrary, it is highly toxic to the human organism. Like mercury, cadmium and its compounds enter the environment only from geological or human activities (metal mining, smelting, and fossil fuel combustion). Cadmium and its compounds are black-listed materials, which by international agreement may not be discharged or dumped into the environment. Cadmium is a cumulative poison and a maximum level of 0.005 ppm is permitted for drinking water. 3.1.2.4 Chromium Most rocks and soils contain small amounts of chromium. Chromium in its naturally occurring state is in a highly insoluble form; however, most of the more common soluble forms found in soils are mainly the result of contamination by industrial emissions. The major uses of chromium are for chrome alloys, chrome plating, oxidizing agents, corrosion inhibitors, pigments for the textile glass and ceramic industries as well as in photography. Hexavalent chromium compounds (soluble) are carcinogenic and the guideline value is 0.05 ppm. 3.1.2.5 Lead Lead is not only the most abundant heavy metals occurring in nature, but it was also one of the first metals used on a large scale by man. Although it is not a nutritionally essential element, its monitoring is important because of its toxicity to human health. Lead is a cumulative poison. Most of the lead produced in metallic form, in batteries, cable sheathing, sheets, and pipes, is recovered and recycled, but most lead used in compound form, like paints and petrol additives, is lost to the environment, eventually ending up in the aquatic environment. Lead compounds, similar to the ones used in petrol additives, are reportedly being used in the production of mercurial fungicides. The presence of lead in drinking water is limited to 0.01 ppm.

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3.1.2.6 Mercury Although a comparatively rare element, mercury is ubiquitous in the environment, the result of natural geological activity and man-made pollution. Mercury from natural sources can enter the aquatic environment via weathering, dissolution, and biological processes. Although extremely useful to man, mercury is also highly toxic to the human organism, especially in the form of methyl mercury, because it cannot be excreted and therefore acts as a cumulative poison. The potential for long-term human health hazards from ingesting mercurycontaminated fish has led several nations to establish regulations and guidelines for allowable sea-food mercury levels. Nearly all levels above 1 ppb in water are due to industrial effluents connected with chlorine and caustic soda production, pharmaceuticals, mirror coatings, mercury lamps, and certain fungicides. 3.1.2.7 Nickel Nickel is ubiquitous in the environment. Nickel is almost certainly essential for animal nutrition, and consequently, it is probably essential to man. Nickel is a relatively nontoxic element; however, certain nickel compounds have been shown to be carcinogenic in animal experiments. 3.1.2.8 Tin Tin and its compounds are significant and controversial chemicals in the environment. As is the case with other elements, not all chemical forms of tin are equally biologically active. In contrast to the low toxicity of inorganic tin (derived from eating canned foods), some organic tin compounds, also known as organotins, are toxic. Tributyltin and triphenyltin, constituents of antifouling paints, are highly toxic and their presence in harbor waters is limited generally to 0.002 and 0.008 ppb respectively. In many countries, organotin antifouling paints are not allowed on vessels less than 25 m long, and the start of a fishing season generally sees an increase of this compound in the water as freshly painted vessels are launched back into the water. 3.1.2.9 Copper The presence of copper in the water supply, although not constituting a hazard to health, may interfere with the intended domestic uses of water. Copper enhances corrosion of aluminum and zinc fittings, stains clothes, and plumbing fixtures. Copper is used in alloys, as a catalyst, in antifouling paints and as a wood preservative. Urban sewage contains substantial amounts of copper. The human taste threshold for copper is low, 5.0
7.0 ppm, and the taste is repulsive. The limit for drinking water is 1.0 ppm. 3.1.2.10 Iron The presence of Iron in drinking water is objectionable for a number of reasons unrelated to health. Under the pH conditions existing in drinking water supplies, ferrous salts are unstable and precipitate as insoluble ferric hydroxide, which settles out as rusty silt.

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Such water tastes unpalatable and promotes the growth of “iron bacteria” and the silt gradually reduces the flow of water in the piping. The recommended guideline level of iron in water is 0.3 ppm. 3.1.2.11 Manganese Anaerobic groundwater often contains elevated levels of dissolved manganese. The presence of Manganese in drinking water is objectionable for a number of reasons unrelated to health. At concentrations exceeding 0.15 ppm, manganese imparts an undesirable taste to beverages and stains plumbing fixtures. The recommended value is 0.1 ppm. 3.1.2.12 Platinum Platinum metal is biologically inert, whereas soluble platinum compounds (e.g., halogenated salts) encountered in occupational settings can cause platinum salt hypersensitivity with symptoms that include bronchitis and asthma after inhalational exposure and contact dermatitis after skin exposure. Animals exposed to chloroplatinate salts used in industry have demonstrated severe hypersensitivity with asthma-like symptoms and anaphylactic shock (Parrot et al., 1969; Saindell and Ruff, 1969). Platinum metal and insoluble salts can produce eye irritation. When ingested or inhaled, platinum metal and insoluble salts are very poorly absorbed (,1% of a dose) and cleared from the body within a week after a single dose. Most absorbed platinum accumulates in the kidneys and is excreted in urine (Moore et al., 1975a, 1975b). The pharmaceutical cisplatin is an animal carcinogen and reasonably anticipated to be a human carcinogen as determined by NTP. The carcinogenicity of other platinum compounds remains uncertain. Workplace air standards for external exposure are established for soluble salts of platinum by OSHA and ACGIH, or recommended for the metal form by NIOSH (Czerczak and Gromiec, 2000). 3.1.2.13 Zinc The concentration of zinc in tap water can be considerably higher than that in surface water owing to the leaching action of zinc from galvanized pipes, brass, and other zinc alloys. Zinc imparts to water an undesirable astringent taste and in concentrations in excess of 5 ppm. The water may appear opalescent and develop a greasy film on boiling. Levels of zinc should be kept well below this value (Table 3.3).

3.1.3 Role of water, air, clay, and fire in scientific characterization Around 450 BCE, a Greek philosopher, Empedocles, characterized all matter into
earth, air, fire, and water. Note that the word “earth” here implies clayey material or dirt it is not the planet earth. The origin of the word “earth” (as a human habitat) originates from the Arabic word Ardha, the root meaning of which is the habitat of the human race or “children of Adam”, lower status, etc. Earth in Arabic is not a planet as there are other words for planet. Similarly, the sun is not a star, it is precisely the one that sustains all energy needs of the earth. The word “air” is Hawa in Arabic is air as in the atmosphere. Note that “air” is not the same as oxygen (or even certain percentage of oxygen, nitrogen, and carbon dioxide)—it is the invisible component of the atmosphere that surrounds the earth. Air must contain all organic emission from earth for it to be “full of life.” It cannot

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TABLE 3.3 Inorganic contaminants found in groundwater. Contaminant

Sources to groundwater

Potential health and other effects

Aluminum

Occurs naturally in some rocks and drainage from mines.

Can precipitate out of water after treatment, causing increased turbidity or discolored water.

Antimony

Enters environment from natural weathering, industrial production, municipal waste disposal, and manufacturing of flame retardants, ceramics, glass, batteries, fireworks, and explosives.

Decreases longevity, alters blood levels of glucose and cholesterol in laboratory animals exposed at high levels over their lifetime.

Arsenic

Enters environment from natural processes, industrial activities, pesticides, and industrial waste, smelting of copper, lead, and zinc ore.

Causes acute and chronic toxicity, liver and kidney damage; decreases blood hemoglobin. A carcinogen.

Barium

Occurs naturally in some limestones, sandstones, and soils in the eastern United States.

Can cause a variety of cardiac, gastrointestinal, and neuromuscular effects. Associated with hypertension and cardiotoxicity in animals.

Beryllium

Occurs naturally in soils, groundwater, and surface Causes acute and chronic toxicity; can water. Often used in electrical industry equipment cause damage to lungs and bones. Possible and components, nuclear power, and space carcinogen. industry. Enters the environment from mining operations, processing plants, and improper waste disposal. Found in low concentrations in rocks, coal, and petroleum and enters the ground and

Cadmium

Found in low concentrations in rocks, coal, and petroleum and enters the groundwater and surface water when dissolved by acidic waters. May enter the environment from industrial discharge, mining waste, metal plating, water pipes, batteries, paints and pigments, plastic stabilizers, and landfill leachate.

Replaces zinc biochemically in the body and causes high blood pressure, liver and kidney damage, and anemia. Destroys testicular tissue and red blood cells. Toxic to aquatic biota.

Chloride

May be associated with the presence of sodium in drinking water when present in high concentrations. Often from saltwater intrusion, mineral dissolution, industrial and domestic waste.

Chromium

Enters environment from old mining operations runoff and leaching into groundwater, fossil fuel combustion, cement-plant emissions, mineral leaching, and waste incineration. Used in metal plating and as a cooling-tower water additive.

Deteriorates plumbing, water heaters, and municipal water-works equipment at high levels. Above secondary maximum contaminant level, taste becomes noticeable. Chromium III is a nutritionally essential element. Chromium VI is much more toxic than Chromium III and causes liver and kidney damage, internal hemorrhaging, respiratory damage, dermatitis, and ulcers on the skin at high concentrations.

Copper

Enters environment from metal plating, industrial and domestic waste, mining, and mineral leaching.

Can cause stomach and intestinal distress, liver and kidney damage, and anemia in high doses. Imparts an adverse taste and significant staining to clothes and fixtures. Essential trace element but toxic to plants and algae at moderate levels. (Continued)

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TABLE 3.3 (Continued) Contaminant

Sources to groundwater

Potential health and other effects

Cyanide

Often used in electroplating, steel processing, plastics, synthetic fabrics, and fertilizer production; also from improper waste disposal.

Poisoning is the result of damage to spleen, brain, and liver.

Dissolved solids

Occur naturally but also enters environment from man-made sources such as landfill leachate, feedlots, or sewage. A measure of the dissolved “salts” or minerals in the water. May also include some dissolved organic compounds.

May have an influence on the acceptability of water in general. May be indicative of the presence of excess concentrations of specific substances not included in the Safe Water Drinking Act, which would make water objectionable. High concentrations of dissolved solids shorten the life of hot water heaters.

Fluoride

Occurs naturally or as an additive to municipal water supplies; widely used in industry.

Decreases incidence of tooth decay but high levels can stain or mottle teeth. Causes crippling bone disorder (calcification of the bones and joints) at very high levels.

Hardness

Result of metallic ions dissolved in the water; reported as concentration of calcium carbonate. Calcium carbonate is derived from dissolved limestone or discharges from operating or abandoned mines.

Decreases the lather formation of soap and increases scale formation in hot water heaters and low-pressure boilers at high levels.

Iron

Occurs naturally as a mineral from sediment and rocks or from mining, industrial waste, and corroding metal.

Imparts a bitter astringent taste to water and a brownish color to laundered clothing and plumbing fixtures.

Lead

Enters environment from industry, mining, plumbing, gasoline, coal, and as a water additive.

Affects red blood cell chemistry; delays normal physical and mental development in babies and young children. Causes slight deficits in attention span, hearing, and learning in children. Can cause slight increase in blood pressure in some adults. Probable carcinogen.

Manganese

Occurs naturally as a mineral from sediment and rocks or from mining and industrial waste.

Causes esthetic and economic damage, and imparts brownish stains to laundry. Affects taste of water, and causes dark brown or black stains on plumbing fixtures. Relatively nontoxic to animals but toxic to plants at high levels.

Mercury

Occurs as an inorganic salt and as organic mercury compounds. Enters the environment from industrial waste, mining, pesticides, coal, electrical equipment (batteries, lamps, switches), smelting, and fossil fuel combustion.

Causes acute and chronic toxicity. Targets the kidneys and can cause nervous system disorders.

Nickel

Occurs naturally in soils, groundwater, and surface Damages the heart and liver of laboratory water. Often used in electroplating, stainless steel animals exposed to large amounts over and alloy products, mining, and refining. their lifetime. (Continued)

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TABLE 3.3 (Continued) Contaminant

Sources to groundwater

Potential health and other effects

Nitrate (as nitrogen)

Occurs naturally in mineral deposits, soils, seawater, freshwater systems, the atmosphere, and biota. More stable form of combined nitrogen in oxygenated water. Found in the highest levels in groundwater under extensively developed areas. Enters the environment from fertilizer, feedlots, and sewage.

Toxicity results from the body’s natural breakdown of nitrate to nitrite. Causes “bluebaby disease,” or methemoglobinemia, which threatens oxygen-carrying capacity of the blood.

Nitrite (combined nitrate/nitrite)

Enters environment from fertilizer, sewage, and human or farm-animal waste.

Toxicity results from the body’s natural breakdown of nitrate to nitrite. Causes “bluebaby disease,” or methemoglobinemia, which threatens oxygen-carrying capacity of the blood.

Selenium

Enters environment from naturally occurring geologic sources, sulfur, and coal.

Causes acute and chronic toxic effects in animals
“blind staggers” in cattle. Nutritionally essential element at low doses but toxic at high doses.

Silver

Enters environment from ore mining and processing, product fabrication, and disposal. Often used in photography, electric and electronic equipment, sterling and electroplating, alloy, and solder. Because of great economic value of silver, recovery practices are typically used to minimize loss.

Can cause argyria, a blue-gray coloration of the skin, mucous membranes, eyes, and organs in humans and animals with chronic exposure.

Sodium

Derived geologically from leaching of surface and Can be a health risk factor for those underground deposits of salt and decomposition of individuals on a low-sodium diet. various minerals. Human activities contribute through deicing and washing products.

Sulfate

Elevated concentrations may result from saltwater intrusion, mineral dissolution, and domestic or industrial waste.

Forms hard scales on boilers and heat exchangers; can change the taste of water, and has a laxative effect in high doses.

Thallium

Enters environment from soils; used in electronics, pharmaceuticals manufacturing, glass, and alloys.

Damages kidneys, liver, brain, and intestines in laboratory animals when given in high doses over their lifetime.

Zinc

Found naturally in water, most frequently in areas where it is mined. Enters environment from industrial waste, metal plating, and plumbing, and is a major component of sludge.

Aids in the healing of wounds. Causes no ill health effects except in very high doses. Imparts an undesirable taste to water. Toxic to plants at high levels.

be reconstituted artificially. The term, “fire” is “naar” in Arabic that refers to real fire, as when wood is burnt and both heat and light are produced. The word has the same root as light (noor), which however has a broader meaning. For instance, moonlight is called noor, whereas sunlight (direct light) is called adha’a. In Arabic, there is a different word for lightning (during a thunderstorm, for instance). The final material “water” is recognized as the

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source of life in every ancient culture. This water is not H2O. In fact, the H2O of modern science that is best described as the combination of atomic hydrogen and oxygen is a toxic product that wouldn’t allow the presence of any life. As the purity of H2O increases, its toxicity goes up and it becomes poisonous to any life form. The word “water” in ancient cultures is best defined as the source of life. The Qur’an recognizes water as the essence of life as well as the source of all mass. In that sense, water is recognized as the first mass created. Such beginning would contradictory to the Big Bang theory that assumes hydrogen to be the first mass form. However, Big Bang narration of nature is flawed and is not consistent with natural phenomena that does not show synthesis of elements to form new materials, instead showing transformation and irreversible merger of particles, much like merger of two galaxies. This has been called the Galaxy model by Islam (2014). In summary, water represents the imbedding of all other forms of material. For water to be the source of life, it must have all ingredients of a life form. Fig. 3.4 shows how depriving water from its natural ingredients can make it reactive to the environment and render it toxic. This graph needs further clarification. Water is a great solvent. It has natural affinity to dissolve numerous salts and minerals that are necessary for life support. One can argue that every component necessary for life is in water. However, this can only occur in case of naturally occurring water. Water is routinely stripped off its solutes by the natural process of evaporation and subsequent precipitation through a series of highly complex and little understood processes. However, this processing prepares water for collecting organic matter that is necessary for life support. This rainwater is pure (in the sense that it has little solute) but it is not toxic or harmfully reactive to the environment. As rainwater comes in contact with soil, it immediately triggers organic transformation of matters and life flourishes. As rain water penetrates the outer crust it picks up minerals and the water becomes even more balanced for human consumption. Another component of human consumption is the water should be free of FIGURE 3.4 Water: a source of life when processed naturally but a potent toxin when processed mechanically.

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organic matters as well as bacteria. As water filters through the soil, it becomes free from these harmful components. So, whenever naturally processed water either becomes useful for human consumption or it becomes useful for other living organisms that are part of a life cycle that includes humans. At later stages of natural processing, a balance is struck, as reflected in Fig. 3.4. On the other hand, if the water is processed through artificial means (marked here as “mechanical”), various life-supporting components are removed and then replaced with toxic artificial components, many of whom are not identified. It is commonly believed that artificially “purified” water has great affinity to absorb back any component from external sources. That’s why such “pure water” is used to clean semiconductors. For the same reason, this water becomes harmful to humans. If ingested, this water starts to absorb all the valuable minerals present in the body. Tests have shown that even as little as a glass of this liquid can have a negative effect on the human body. This process produces water of particularly high toxicity when reverse osmosis and nanofiltration are used. The World Health Organization (WHO) determined that demineralized water increased diuresis and the elimination of electrolytes, with decreased serum potassium concentration. Magnesium, calcium, and other nutrients in water can help to protect against nutritional deficiency. Recommendations for magnesium have been put at a minimum of 10 mg/L with 20
30 mg/L optimum; for calcium a 20 mg/L minimum and a 40
80 mg/L optimum, and a total water hardness (adding magnesium and calcium) of 2
4 mmol/L. At water hardness above 5 mmol/L, higher incidence of gallstones, kidney stones, urinary stones, arthrosis, and arthropathies has been observed. For fluoride, the concentration recommended for dental health is 0.5
1.0 mg/L, with a maximum guideline value of 1.5 mg/L to avoid dental fluorosis (Kozisek, 2005). A significant portion of essential minerals is derived from water. “Purified” water does not contain these essential minerals and thereby causes disruption to the metabolic process, thereby causing harm (Rahman and Islam, 2018). When the residual components in “purified water” contains toxins, such as the ones released from membrane during the reverse osmosis process, the process becomes particularly toxic, as shown in the lower half of Fig. 5.51. Picture 5.1 shows the essence of natural processing of water. Formation of cloud through evaporation, rain, photosynthesis, filtration in the soil, and others form an integral part of a life support system that is opposite to the mechanical system in every step of the way. It is also true that energy in an organic system emerges from water, just like life. As life cycle continues, mass transfer takes place simultaneous to energy exchange. By assigning zero mass to energy, this continuity is missed in the analysis adapted in New Science. In all, the characterization credited to Empedocles and known to modern Europe conforms to the criterion of phenomena as outlined in the work of Islam et al. (2010) as well as Khan and Islam (2007). This fundamental criterion can be stated as not violating the properties of nature. In fact, this characterization has the following strengths: (1) definitions are real, meaning have phenomenal first premise; (2) it recognizes the continuity in nature (including that between matter and energy); (3) captures the essence of natural lifestyle. With this characterization, nuclear energy would not emerge as an energy source. Fluorescent light would not qualify for natural light. With this characterization, none of the unsustainable technologies of today would come into existence.

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3.2 Comprehensive mass and energy balance 3.2.1 Rebalancing mass and energy Mass and energy balances inspected in depth disclose intention as the most important parameter, as the sole feature that renders the individual accountable to, and within, nature. This is rife with serious consequences for the black-box approach of conventional engineering, because a key assumption of the black-box approach stands in stark and howling contradiction to one of the key corollaries of that most fundamental principle of all: the Law of Conservation of Matter. In fact, this is only possible if there is no leak anywhere and no mass can flow into the system from any other point. However, mass can flow into the system from any other point—thereby rendering the entire analysis a function of tangible measurable quantities; that is, a “science” of tangibles-only (Fig. 3.5). The mass conservation theory indicates that the total mass is constant. It can be expressed as follows: N X

mi 5 Constant

(3.1)

0

where m is the mass and i is the number from 0 to N. In the true sense, this mass-balance encompasses mass from macroscopic to microscopic and detectable to undetectable; that is, from tangible to intangible. Therefore, the true statement should be as illustrated in Fig. 3.6: ‘‘Known mass-in’’ 1 ‘‘Unknown mass-in’’ 5 ‘‘Known mass-out 1 ‘‘Unknown mass-out’’ (3.2) 1 ‘‘Known accumulation’’ 1 ‘‘Unknown accumulation’’

The unknown masses and accumulations are neglected, which means they are considered to be equal to zero. Every object has two masses: 1. Tangible mass. 2. Intangible mass, usually neglected. Then, Eq. (3.2) becomes N X i50

min;i 1

N X i50

0min;i 5

N X

mout;i 1

i50

N X

0mout;i 1

i50

N X i50

macc;i 1

N X

0macc;i

(3.3)

i50

The unknowns can be considered intangible, yet essential to include in the analysis as they incorporate long-term and other elements of the current timeframe. In nature, the deepening and broadening of order are continually observed, with many pathways, circuits, and parts of networks being partly or even completely repeated and FIGURE Known Mass in

Known Accumulation

Known Mass out

3.5 Conventional incorporating only tangibles.

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FIGURE

3.6 Mass-balance equation incorporating tangibles and intangibles.

Unknown Mass in

Known Accumulation Known Mass in

Known Mass out Unknown Accumulation

Unknown Mass out

the overall balance being further enhanced. Does this actually happen as arbitrarily as conventionally assumed? A little thought suggests this must take place as a principle as a result and/or as a response to human activities and the response of the environment to these activities and their consequences. Nature itself has long established its immediate and unbreachable dominion over every activity and process of everything in its environment, and there are no other species that can drive nature into such modes of response. In the absence of the human presence, nature would not be provoked into having to increase its order and balance, and everything would function in the “zero net waste” mode. An important corollary of the Law of Conservation of Mass, that mass can be neither created nor destroyed, is that there is no mass that can be considered in isolation from the rest of the universe. Yet, the black-box model clearly requires just such an impossibility. Since, however, human ingenuity can select the time frame in which such a falsified “reality” will be exactly what the observer perceives, the model of the black box can be substituted for reality and the messy business of having to take intangibles into account is foreclosed once and for all.

3.2.2 Energy: toward scientific modeling There have been a number of theories developed in the past centuries to define energy and its characteristics. However, none of the theories is enough to describe energy properly. All of the theories are based on much idealized assumptions, which have never existed practically. Consequently, the existing model of energy and its relation to others cannot be accepted confidently. For instance, the second law of thermodynamics depends on Carnot cycle in the classical thermodynamics where none of the assumptions of Carnot’s cycle exists in reality. Definitions of ideal gases, reversible processes, and adiabatic processes used in describing the Carnot’s cycle are imaginary. In 1905 Einstein came up with his famous equation, E 5 mc2, which states an equivalence between energy (E) and relativistic mass (m), in direct proportion to the square of the speed of light in a vacuum (c2). However, the assumptions of constant mass and the concept of vacuum do not exist in reality. Moreover, this theory was developed on the basis of Planck’s constant which was derived from black body radiation. Perfectly black bodies do not even exist in

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reality. So, it is found that the development of every theory is dependent on a series of assumptions that do not exist in reality. The scientific approach must include restating the mass balance. For whatever else remains unaccounted for, the mass-balance equation, which in its conventional form necessarily falls short of explaining the functionality of nature coherently as a closed system, is supplemented by the energy balance equation. For any time, the energy balance equation can be written as follows: ðN X

ai 5 Constant; i going from 1 to infinity

(3.4)

0

where a is the activity equivalent to potential energy. In the above equation, only potential energy is taken into account. Total potential energy, however, must include all forms of activity, and here once again, a large number of intangible forms of activity, for example, the activity of molecular and smaller forms of matter, cannot be “seen” and accounted for in this energy balance. The presence of human activity introduces the possibility of other potentials that continually upset the energy balance in nature. There is overall balance but some energy forms, for example, electricity (either from combustion or nuclear sources), would not exist as a source of useful work except for human intervention, which continually threaten to push this into a state of imbalance. In the definition of activity, both time and space are included. The long term is defined by time being taken to infinity. The “zero waste” condition is represented by space going to infinity. There is an intention behind each action and each action is playing an important role in creating overall mass and energy balance. The role of intention is not to create a basis for prosecution or enforcement of certain regulations. It is rather to provide the individual with a guideline. If the product or the process is not making things better with time, it is fighting nature—a fight that cannot be won and is not sustainable. Intention is a quick test that will eliminate the rigorous process of testing feasibility, long-term impact, etc. Only with “good” intention can things improve with time. After that, other calculations can be made to see how fast the improvements will take place. In clarifying the intangibility of an action or a process, the equation has some constant which is actually an infinite series: a5

N X

ai 5 a0 1 a1 1 a2 1 a3 1 . . .

(3.5)

0

If each term of Eq. (3.8) converges, it will have a positive sign, indicating intangibility; hence, the effect of each term thus becomes important for measuring the intangibility overall. On this path, it should also become possible to analyze the effect of any one action and its implications for sustainability overall as well. It can be inferred that man-made activities are not enough to change the overall course of nature. Failure up until now, however, to include an accounting for the intangible sources of mass and energy, has brought about a state of affairs in which, depending on

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the intention attached to such interventions, the mass
energy balance can either be restored and maintained over the long term, or increasingly threatened and compromised in the short term. In the authors’ view, it would be far better to develop the habit of investigating nature and the prospects and possibilities it offers Humanity’s present and future, by considering time t at all scales, going to infinity, and giving up once and for all the habit of resorting to time scales that appear to serve some immediate ulterior interest in the short term but which in fact have nothing to do with natural phenomena, must therefore lead to something that will be antinature in the long term and the short term. The main obstacle to discussing and positioning the matter of human intentions within the overall approach to the Laws of Conservation of Mass, Energy and Momentum stems from notions of the so-called “heat death” of the universe, predicted in the 19th century by Lord Kelvin and enshrined in his Second Law of Thermodynamics. In fact, however, this idea that the natural order must “run down” due to entropy, eliminating all sources of “useful work,” naively attempts to assign what amounts to a permanent and decisive role for negative intentions in particular without formally fixing or defining any role whatsoever for human intentions in general. Whether they arise out of the black-box approach of the mass-balance equation or the unaccounted missing potential energy sources in the energy balance equation, failures in the short term become especially highly consequential when they are used by those defending the status quo to justify antinature “responses” of the kind well-described elsewhere as typical examples of “the roller coaster of the Information Age” (Islam et al., 2022).

3.2.3 The law of conservation of mass and energy Lavoisier’s first premise was “mass cannot be created or destroyed.” This assumption does not violate any of the features of nature. However, his famous experiment had some assumptions embedded in it. When he conducted his experiments, he assumed that the container was sealed perfectly—something that would violate the fundamental tenet of nature that an isolated chamber can be created. Rather than recognizing the aphenomenality of the assumption that a perfect seal can be created, he “verified” his first premise (law of conservation of mass) “within experimental error.” Einstein’s famous theory is more directly involved with mass conservation. He derived E 5 mc2 using the first premise of Planck (1901). However, in addition to the phenomenal premises of Planck, this famous equation has its own premises that are a phenomenal. However, this equation remains popular and is considered to be useful (in the pragmatic sense) for a range of applications, including nuclear energy. For instance, it is quickly deduced from this equation that 100 kJ is equal to approximately 1029 g. Because no attention is given to the source of the matter nor of the pathway, the information regarding these two important intangibles is wiped out from the conventional scientific analysis. The fact that a great amount of energy is released from a nuclear bomb is then taken as evidence that the theory is correct. By accepting this at face value (heat as a one-dimensional criterion), heat from nuclear energy, electrical energy, electromagnetic irradiation, fossil fuel burning, wood burning, or solar energy, becomes identical.

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In terms of the well-known laws of conservation of mass (m), energy (E), and momentum (p), the overall balance, B, within nature may be defined as some function of all of them, as follows:   B 5 f m; E; p (3.6) The perfection without stasis that is nature means that everything that remains in balance within it is constantly improving with time. That is written as follows: dB . 0: dt

(3.7)

If the proposed process has all concerned elements so that each element is following this pathway, none of the remaining elements of the mass balance discussed later will present any difficulties. Because the final product is being considered as time extends to infinity, the positive ( . 0) direction is assured.

3.2.4 Avalanche theory A problem posed by Newton’s Laws of Motion, however, is the challenge they represent of relying upon and using the principle of energy-mass-momentum conservation. This principle is the sole necessity and the sufficient condition for analyzing and modeling natural phenomena in situ, so to speak—as opposed to analyzing and generalizing from fragments captured or reproduced under controlled laboratory conditions. The underlying problem is embedded in Newton’s very notion of motion as the absence of rest, coupled with his conception of time as the duration of motion between periods of rest. The historical background and other contradictions of the Newtonian system arising from this viewpoint are examined at greater length in Abou-Kassem et al. (2008), an article that was generated as part of an extended discussion of, and research into, the requisites of a mathematics that can handle natural phenomena unadorned by linearizing or simplifying assumptions. Here the aim is to bring forward those aspects that are particularly consequential for approaching the problems of modeling phenomena of nature, where “rest” is impossible and inconceivable. Broadly speaking, it is widely accepted that Newton’s system, based on his three laws of motion accounting for the proximate physical reality in which humans live on this Earth coupled with the elaboration of the principle of universal gravitation to account for motion in the heavens of space beyond this Earth, makes no special axiomatic assumptions about physical reality outside the scale on which any human being can observe and verify for himself/herself (i.e., the terrestrial scale on which we go about living daily life). For example, Newton posits velocity, v, as a change in the rate at which some mass displaces its position in space; s, relative to the time duration; t, of the motion of the said mass. That is written as follows: v5

@s @t

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This is no longer a formula for the average velocity, measured by dividing the net displacement in the same direction as the motion impelling the mass by the total amount of time that the mass was in motion on that path. This formula posits something quite new (for its time, viz., Europe in the 1670s), actually enabling us to determine the instantaneous velocity at any point along the mass’s path while it is still in motion. The “v” that can be determined by the formula given in Eq. (3.8) above is highly peculiar. It presupposes two things. First, it presupposes that the displacement of an object can be derived relative to the duration of its motion in space. Newton appears to cover that base already by defining this situation as one of what he calls “uniform motion.” Secondly, however, what exactly is the time duration of the sort of motion Newton is setting out to explain and account for? It is the period in which the object’s state of rest is disturbed, or some portion thereof. This means the uniformity of the motion is not the central or key feature. Rather, the key is the assumption in the first place that motion is the opposite of rest. In his First Law, Newton posits motion as the disturbance of a state of rest. The definition of velocity as a rate of change in spatial displacement relative to some time duration means that the end of any given motion is either the resumption of a new state of rest or the starting point of another motion that continues the disturbance of the initial state of rest. Furthermore, only to an observer external to the mass under observation can motion appear as the disturbance of a state of rest and can a state of rest appear as the absence or termination of motion. Within nature, meanwhile, is anything ever at rest? The struggle to answer this question exposes the conundrum implicit in the Newtonian system: everything “works”—all systems of forces are “conservative”—if and only if the observer stands outside the reference frame in which a phenomenon is observed. In Newton’s mechanics, motion is associated not with matter-as-such, but only with force externally applied. Inertia, on the other hand, is definitely ascribed to mass. Friction is considered only as a force equal and opposite to that which has impelled some mass into motion. Friction, in fact, exists at the molecular level, however, as well as at all other scales—and it is not a force externally applied. It is a property of matter itself. It follows that motion must be associated fundamentally not with forces applied to matter, but rather with matter itself. Although Newton nowhere denies this possibility, his First Law clearly suggests that going into motion and ceasing to be in motion are equal functions of some application of force external to the matter in motion; that is, motion is important relative to some rest or equilibrium condition. Following Newton’s presentation of physical reality in his Laws of Motion, if time is considered mainly as the duration of motion arising from forces externally applied to matter, then it must cease when an object is “at rest.” Newton’s claim in his First Law of Motion that an object in motion remains in (uniform) motion until acted on by some external force appears at first to suggest that, theoretically, time is taken as being physically continual. It is mathematically continuous, but only as the independent variable, and indeed, according to Eq. (3.8) above, velocity v becomes undefined if time duration t becomes 0. On the other hand, if motion itself ceases—in the sense of @s, the rate of spatial displacement, going to 0—then velocity must be 0. What has then happened, however, to time? Where in nature can time be said either to stop or to come to an end? If Newton’s mechanism is accepted as the central story, then many natural phenomena have been

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operating as special exceptions to Newtonian principles. While this seems highly unlikely, its very unlikelihood does not point to any way out of the conundrum. This is where momentum p, and—more importantly—its “conservation,” comes into play. In classical Newtonian terms, it is written as follows: p 5 mv 5 m

@s @t

(3.9)

Hence, @p @ @s @2 s 5 m 1m 2 @t @t @t @t

(3.10)

If the time it takes for a mass to move through a certain distance is shortening significantly as it moves, then the mass must be accelerating. An extreme shortening of this time corresponds therefore to a proportionately large increase in acceleration. However, if the principle of conservation of momentum is not to be violated, either 1. the rate of its increase for this rapidly accelerating mass is comparable to the increase in acceleration—in which case the mass itself will appear relatively constant and unaffected; or 2. mass itself will be increasing, which suggests that the increase in momentum will be greater than even that of the mass’s acceleration; or 3. mass must diminish with the passage of time, which implies that any tendency for the momentum to increase also decays with the passage of time. The rate of change of momentum (@p/@t) is proportional to acceleration (the rate of change in velocity, as expressed in the @2s/@t2 term) experienced by the matter in motion. It is proportional as well to the rate of change in mass with respect to time (the @m/@t term). If the rate of change in momentum approaches the acceleration undergone by the mass in question, that is, if @p/@t - @2s/@t2, then the change in mass is small enough to be neglected. On the other hand, a substantial rate of increase in the momentum of some moving mass—on any scale much larger than its acceleration—involves a correspondingly substantial increase in mass. The analytical standpoint expressed in Eqs. (3.9) and (3.10) above work satisfactorily for matter in general, as well as for Newton’s highly specific and indeed peculiar notion of matter in the form of discrete object masses. Of course, here it is easy to miss the “catch.” The “catch” is the very assumption in the first place that matter is an aggregation of individual object masses. While this may well be true at some empirical level at a terrestrial scale—10 balls of lead shot, say, or a cubic liter of wood subdivided into exactly 1000 onecm by one-cm by one-cm cubes of wood—it turns out in fact to be a definition that addresses only some finite number of properties of specific forms of matter that also happen to be tangible and hence accessible to us at a terrestrial scale. Once again, the generalizing of what may only be a special case—before it has been established whether the phenomenon is a unique case, a special but broad case, or a characteristic case—begets all manner of mischief. To appreciate the implications of this point, consider what happens when an attempt is made to apply these principles to object masses of different orders and/or vastly different

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scales but within the same reference frame. Consider the snowflake—a highly typical piece of atmospheric mass. Compared to the mass of some avalanche of which it may come to form a part of, the mass of any individual component snowflake is negligible. Negligible as it may seem; however, it is not zero. Furthermore, the accumulation of snowflakes in the avalanching mass of snow means that the cumulative mass of snowflakes is heading toward something very substantial, infinitely larger than that of any single snowflake. To grasp what happens for momentum to be conserved between two discrete states, consider the starting point: p 5 mv. Clearly, in this case, that would mean in order for momentum to be conserved: pavalanche 5 psnowflakes-as-a-mass

(3.11)

which means mavalanche vavalanche 5

N X

msnowflake vsnowflake

(3.12)

snowflake51

At a terrestrial scale, avalanching is a readily observed physical phenomenon. At its moment of maximum (destructive) impact, an avalanche indeed looks like a train-wreck unfolding in very slow motion. However, what about the energy released in the avalanche? Of this, we can only directly see the effect, or footprint—and another aphenomenal absurdity pops out: an infinitude of snowflakes, each of negligible mass, have somehow imparted a massive release of energy. This is a serious accounting problem—not only momentum, but mass and energy as well, are to be conserved throughout the universe. The same principle of conservation of momentum enables us to “see” what must happen when an electron or electrons bombard a nucleus at a very high speed. Now we are no longer observing or operating at the terrestrial scale. Once again, however, the explanation conventionally given is that since electrons have no mass, the energy released by the nuclear bombardment must have been latent and entirely potential, stored within the nucleus. Clearly, then, as an accounting of what happens in nature (as distinct from a highly useful toolset for designing and engineering certain phenomena involving the special subclass of matter represented by Newton’s object masses), Newton’s central model of the object mass is insufficient. Is it even necessary? Tellingly, on this score, the instant it is recognized that there is no transmission of energy without matter, all the paradoxes we have just elaborated on are removable. Hence, we may conclude that for properly understanding and becoming enabled to emulate nature at all scales, the mass
energy balance and the conservation of momentum are necessary and sufficient. On the other hand, neither the constancy of mass, nor the speed of light, nor even uniformity in the passage and measure of time is necessary or sufficient. This realization holds considerable importance for how problems of modeling nature are addressed. An infinitude of energy and mass transfers take place in nature, above and to some extent in relation to the surface of the earth, comprising altogether a large part of the earth’s “life cycle.” In order to achieve any nontrivial model of nature, time itself becomes a highly active factor of prepossessing—and even overwhelming—importance. Its importance is perhaps comparable only to the overwhelming role that time plays in sorting out the geology transformations under way inside the earth.

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3.2.5 Simultaneous characterization of matter and energy The key to the sustainability of a system lies within its energy balance. In this context, Eq. (3.12) is of utmost importance. This equation can be used to define any process, for which the following equation applies: Qin 5 Qacc: 1 Qout

(3.13)

In the above equation, Qin expresses the inflow of matter, Qacc represents the same for accumulating matter, and Qout represents the same for the outflowing of matter. Qacc will have all terms related to dispersion/diffusion, adsorption/desorption, and chemical reactions. This equation must include all available information regarding inflow matters, for example, their sources and pathways, the vessel materials, catalysts, and others. In this equation, there must be a distinction made among various matters, based on their sources and pathways. Three categories are proposed: 1. Biomass (BM). 2. Convertible nonbiomass (CNB). 3. Nonconvertible nonbiomass (NCNB). Biomass is any living object. Even though conventionally dead matter is also called biomass, we avoid that denomination as it is difficult to scientifically discern when a matter becomes nonbiomass after death. The convertible nonbiomass (CNB) is the one that due to natural processes will be converted to biomass. For example, a dead tree is converted into methane after microbial actions; the methane is naturally broken down into carbon dioxide, and plants utilize this carbon dioxide in the presence of sunlight to produce biomass. Finally, nonconvertible nonbiomass (NCNB) is a matter that emerges from human intervention. These matters do not exist in nature and their existence can only be considered artificial. For instance, synthetic plastic matters (e.g., polyurethane) may have a similar composition as natural polymers (e.g., human hair, leather), but they are brought into existence through a very different process than that of natural matters. Similar examples can be cited for all synthetic chemicals, ranging from pharmaceutical products to household cookwares. This denomination makes it possible to keep track of the source and pathway of a matter. The principle hypothesis of this denomination is as follows: all matters naturally present on Earth are either BM or CNB, with the following balance: Matter from natural source 1 CNB1 5 BM 1 CNB2

(3.14)

The quality of CNB2 is different from or superior to that of CNB1 in the sense that CNB2 has undergone one extra step of natural processing. If nature is continuously moving to better the environment (as represented by the transition from a barren Earth to a green Earth), CNB2 quality has to be superior to CNB1 quality. Similarly, when matter from natural energy sources comes in contact with BMs, the following equation can be written: Matter from natural source 1 BM1 5 BM2 1 CNB

(3.15)

Applications of this equation can be cited from biological sciences. When sunlight comes in contact with retinal cells, vital chemical reactions take place that results in the

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nourishment of the nervous system, among others (Chhetri and Islam, 2008). In these mass transfers, chemical reactions take place entirely differently depending on the light source, the evidence of which has been reported in numerous publications. Similarly, sunlight is also essential for the formation of vitamin D, which is in itself essential for numerous physiological activities. In the above equation, vitamin D would fall under BM2. This vitamin D is not to be confused with the synthetic vitamin D, the latter one being the product of artificial processes. It is important to note that all products on the right-hand side are of greater value than the ones on the left-hand side. This is the inherent nature of natural processing—a scheme that continuously improves the quality of the environment, and is the essence of sustainable technology development. The following equation shows how energy from NCNB will react with various types of matter. Matter from unnatural source 1 BM1 5 NCNB2

(3.16)

An example of the above equation can be cited from biochemical applications. For instance, if artificially generated UV comes in contact with bacteria, the resulting bacteria mass would fall under the category of NCNB, stopping further value addition by nature. Similarly, if bacteria are destroyed with synthetic antibiotic (pharmaceutical product, pesticide, etc.), the resulting product will not be conducive to value addition through natural processes, instead becoming a trigger for further deterioration and insult to the environment. Matter from unnatural source 1 CNB1 5 NCNB3

(3.17)

An example of the above equation can be cited from biochemical applications. The NCNB1 which is created artificially reacts with CNB1 (such as N2, O2) and forms NCNB3. The transformation will be in a negative direction, meaning the product is more harmful than it was earlier. Similarly, the following equation can be written: Matter from unnatural source 1 NCNB1 5 NCNB2

(3.18)

An example of this equation is that sunlight leads to photosynthesis in plants, converting NCBM to MB, whereas fluorescent lighting, which would freeze that process, can never convert natural nonbiomass into biomass. The principles of the nature model proposed here are restricted to those of mass (or material) balance, energy balance, and momentum balance. For instance, in a nonisothermal model, the first step is to resolve the energy balance based on temperature as the driver for some given time period, the duration of which has to do with characteristic time of a process or phenomenon. This is a system that manifests phenomena of thermal diffusion, thermal convection, and thermal conduction, without spatial boundaries but nonetheless giving rise to the “mass” component. The key to the system’s sustainability lies within its energy balance. Here is where natural sources of biomass and nonbiomass must be distinguished from nonnatural, noncharacteristic, industrially synthesized sources of nonbiomass. Fig. 3.7 envisions the environment of a natural process as a bioreactor that does not and will not enable conversion of synthetic nonbiomass into biomass. The key problem of mass balance in this process, as in the entire natural environment of the earth as a whole,

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FIGURE 3.7 Sustainable pathway for material substance in the environment.

FIGURE 3.8 Synthetic nonbiomass that cannot be converted into biomass will accumulate far faster than naturally sourced nonbiomass, which can potentially always be converted into biomass.

is set out in Fig. 3.8: the accumulation rate of synthetic nonbiomass continually threatens to overwhelm the natural capacities of the environment to use or absorb such material. In evaluating Eq. (3.18), it is desirable to know all of the contents of the inflow matter. However, it is highly unlikely to know all the contents, even at a macroscopic level. In absence of a technology that would find the detailed content, it is important to know the pathway of the process to have an idea of the source of impurities. For instance, if deionized water is used in a system, one would know that its composition would be affected by the process of deionization. Similar rules apply to products from organic sources, etc. If we consider the combustion reaction (coal, for instance) in a burner, the bulk output will likely be CO2. However, this CO2 will be associated with a number of trace chemicals

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FIGURE 3.9 Results from carbon combustion in a natural reactor and an artificial reactor.

(impurities) depending upon the process it passes through. Because, Eq. (3.18) includes all known chemicals (e.g., from source, adsorption/desorption products, catalytic reaction products), it would be able to track matters in terms of CNB and NCNB products. Automatically, this analysis will lead to differentiation of CO2 in terms of the pathway and the composition of the environment which is the basic requirement of Eq. (3.18). According to Eq. (3.18), charcoal combustion in a burner made up of clay will release CO2 and natural impurities of charcoal and the materials from the burner itself. Similar phenomenon can be expected from a burner made up of nickel plated with an exhaust pipe made up of copper. Anytime, CO2 is accompanied with CNB matter, it will be characterized as beneficial to the environment. This is shown in the positive slope of Fig. 3.9. On the other hand, when CO2 is accompanied with NCNB matter, it will be considered to be harmful to the environment, as this is not readily acceptable by the ecosystem. For instance, the exhaust of the Cu or Ni-plated burner (with catalysts) will include chemicals, for example, nickel, copper from pipe, trace chemicals from catalysts, besides bulk CO2 because of adsorption/ desorption, catalyst chemistry, etc. These trace chemicals fall under the category of NCNB and cannot be utilized by plants (negative slope from Fig. 3.9). This figure clearly shows that the upward slope case is sustainable as it makes an integral component of the ecosystem. With the conventional mass-balance approach, the bifurcation graph of Fig. 3.9 would be incorrectly represented by a single graph that is incapable of discerning between the different qualities of CO2 because the information regarding the quality (trace chemicals) is lost in the balance equation.

3.2.6 Modeling energy spectrum Energy spectrum has been modeled with a general consensus that particles can be characterized simultaneously as both a stream of particles and a wave. Einstein famously

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predicted “stimulated emission of radiation,” which was the theoretical basis for the laser (Einstein, 1916). It was first Bose, who floated the concept of “degenerated” gas to connect mass and energy through radiation (Einstein, 1924, 1925). Einstein termed the transition from mass (as in ideal gas) to energy (radiative state) as “quantum gas.” Their derivation relied on the validity of Planck radiation formula. Combescot et al. (2017) reviewed Bose
Einstein condensation (BEC) theories and applications. Although the context was semiconductor excitons, that review disclosed several underlying premises. The most important one is that exciton condensate is dark and hence decoupled from light. This premise is supplemented with the existence of elementary bosons, with certain spin degrees of freedom (Ornes, 2017). The premise of “ground-state excitons are dark” is later replaced with a “gray” state, which is attained past a density threshold, thus allowing light to be coupled with matter (Flayac, 2012). This narrative and follow-up descriptions introduce more complexity (Albiez et al., 2005) without answering the fundamental question as to how to characterize mass and energy simultaneously. Interestingly, such gap in knowledge also exists in matters of material characterization (Wagner et al., 2014). This is of particular relevance when it comes to nanomaterials. Penrose (1994) was the first scientist to reconcile quantum theory of light with macroscale application. Hameroff and Penrose (2014) review the extension of Quantum to explain the nature and behavior of matter and energy in macroscale. The proposed comprehensive model starts with a revised form of the Bose
Einstein condensation light theory, replacing the “ideal gas” assumption with “galaxy” formed with “particles” with trackers of their origins. This will allow one to introduce different matter and energy trajectories for different energy spectra. Although the Einstein’s original theory did not have a boundary between matter and energy, this distinction has been made by recent scientists (Wu et al., 2017; Cola and Piovella, 2004). While much progress has been made in developing so-called phase diagram of condensate matter, few considered developing a theory that would allow a smooth transition between matter and energy (Oertel et al., 2017; Kucher, 2017). This is done in the avalanche model by assuring continuity for all subatomic particles, all the way down to their photonic existence. Mathematically, this continuity removes a number of spurious conditions, thus making it amenable to practical solutions. This also eliminates the need to introduce the notion of “consciousness” as done by Penrose. The resulting description can explain the interactions between electrons from high-voltage radiation and photons from MF. It will also allow inclusion of geometric configurations within the radiotherapy protocol (St Aubin et al., 2010). Table 3.4 lists the existence of yin
yang in all aspects of life. Note that the first line represents the original meaning in ancient Chinese. The last line represents the modern physics terminology. The pictorial expression is shown in Fig. 3.10. This representation is in yin
yang form, is important, and is distinct from New Science (post-Newtonian) description (Zhang and Shao, 2012). This depiction gives one an opportunity to maintain continuous interaction between matter and energy. This enables to maintain continuity in true reflection of simultaneous conservation of mass/energy. It was first Bose, who floated the concept of “degenerated” gas to connect mass and energy through radiation (Einstein, 1925). Einstein termed the transition from mass (as in ideal gas) to energy (radiative state) as “quantum gas.” Their derivation relied on the

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TABLE 3.4 Yin
yang in colloquial and scientific terms. Yang

Yin

Sun

Moon

Outer space

Earth

Light

Darkness

Fire

Water

Time

Space

Activity

Rest

Expansion

Contraction

Rising

Descending

Above

Below

Male

Female

Qi (energy)

Blood and bodily fluids

Energy

Matter

FIGURE 3.10 Yin
yang representation of matter and energy.

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validity of Planck radiation formula. Planck assumed the atoms of the cavity emit and absorb radiation in the form of packets of energy, called quanta. The energy of each quantum is directly proportional to frequency. In 1900 Max Planck gave a new concept about the nature of radiation, called the quantum theory of radiation in which Planck assumed the discrete nature of radiation. He assumed the atoms of the cavity emit and absorb radiation in the form of packets of energy, called quanta. The energy of each quantum is directly proportional to frequency: E~f E 5 hf where h is Planck’s constant. Max Planck made the following assumptions to derive his radiation law: • The atoms of the cavity behave like tiny harmonic oscillators. • The oscillators radiate and absorb energy only in the form of packets or bundles of electromagnetic waves. • An oscillator can emit or absorb any amount of energy which is the integral multiple of “hf” which is mathematically expressed as follows: E 5 nhf; where n is an integer. Another phenomenon that classical physics could not explain was the emission of radiation by a black body. A black body is an object capable of absorbing all the radiation that comes to it without reflecting anything. The intensity of the radiation emitted by a black body varies with the wavelength according to a characteristic curve that has a maximum dependent on body temperature. According to classical theory, the intensity of the radiation emitted by the black body should increase, as the wavelength decreases, becoming infinite, behavior that lacks physical sense. When a body is heated, it emits radiation. The nature of the radiation depends upon the temperature. At low temperature, a body emits radiation which is the principal of long wavelengths in the invisible infrared region. At high temperature, the proportion of shorter wavelength radiation increases. Furthermore, the amount of emitted radiation is different for different wavelengths. It is of interest to see how the energy is distributed among different wavelengths at various temperatures. For example, when the platinum wire is heated, it appears dull red at about 500 C, changes to cherry red at 900 C, becomes orange-red at 1100 C, yellow at 1300 C and finally white at about 1600 C. This shows that as the temperature is increased, the radiation becomes richer in shorter wavelengths. Lummer and Pringsheim (1900) measured the intensity of emitted energy with wavelength radiated from a black body at different temperatures. The amount of radiation emitted with different wavelengths is shown in the form of energy distribution curves for each temperature in Fig. 3.11. These curves reveal the following interesting facts: 1. At a given temperature, the energy is not uniformly distributed in the radiation spectrum of the body.

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FIGURE 3.11 The spectrum of radiation emitted from a quartz surface (median thick curve) and the blackbody radiation curve (black curve) at 600K.

2. At a given temperature T, the emitted energy has maximum value for a certain wavelength λmax and the product λmax 3 T remains constant. λmax 3 T 5 Constant. . .

(3.19)

23

The value of the constant is about 2.9 3 10 m/K. This equation means that as T increases, λ shifts to the shorter wavelength. For all wavelengths, an increase in temperature causes an increase in energy emission. The radiation intensity increases with an increase in wavelengths and at a particular wavelength λmax, it has a maximum value. With a further increase in wavelength, the intensity of radiation decreases. The area under each curve represents the total energy (E) radiated over all wavelengths at a particular temperature. It is found that area is directly proportional to the fourth power of kelvin temperature T. Thus E ~ T4 OR E 5 σT 4 . . .

(3.20)

where σ is called Stephen’s constant. Its value is 5.67 3 1026 Wm2/k4 and the above relation is known as Stephen Boltzmann law. The electromagnetic wave theory of radiation cannot explain the energy distribution along the intensity
wavelength curves. The successful attempts to explain the shape of energy distribution curves gave rise to a new and nonclassical view of electromagnetic

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radiation. In 1900, Max plank founded a mathematical model resulting in an equation that describes the shape of observed curves exactly. He suggested that energy is radiated or absorbed in discrete packets, called quanta rather than as a continuous wave. Each quantum is associated with radiation of a single frequency. The energy E of each quantum is proportional to the frequency f, and E 5 hf. . .

(3.21)

where h is Plank’s constant. Its value is 6.63 3 10234 J/s21. This fundamental constant is important in physics as the constant c, the speed of light in vacuum. With regard to the theory of ideal gases, it is generally understood that volume and temperature of a given amount of gas can be freely chosen without constraint. The theory then determines the energy or, respectively, the pressure of the gas. Planck’s formulation was the starting point of Bose
Einstein theory of condensate. They postulate for any given temperature there exists a maximum density of agitated molecules. When exceeding this density the surplus molecules will drop out as immobile (“condensing” without forces of attraction). What is peculiar is that the “saturated ideal gas” simultaneously represents the situation of maximal possible density of moving gas molecules as well as the specific density at which the gas is in thermodynamic equilibrium with the “condensed substance.” This analogy with “oversaturated gas” does not exist for ideal gases. Ehrenfest and other colleagues criticized Bose’s theory of radiation and my analog treatment of ideal gasses for not explicitly stating that in these theories the quanta, respectively molecules, are not treated as statistical independent entities. While this is correct, it does not point to the fact that the mere representation of energy into a series of independent packages of energy disconnects energy from the mass source. Such assumptions are not necessary if one uses the galaxy model, proposed by Islam (2014). This model describes this process as equivalent to merger of two galaxies in which each of them has numerous components with respective natural frequencies. However, after the merger occurs (physical or chemical), the resulting products have a frequency that is different from previous ones. If each particle is tagged, this model can help track a natural process apart from an artificial process. Fig. 3.12 shows how this model casts the number of particles with their respective numbers in a natural system. Here, no distinction is made between light particle and mass particle as imposing such a distinction is contrary to natural order and renders the model aphenomenal. This depiction is equally valid in describing energy balance as well as mass balance, as the boundary between mass fundamental particle and energy “particles” is removed. As such Figure 2.5 can also represent any natural flame that will have a smooth spectrum as shown in the spectrum of the sunlight. Any alteration of light source would create a spectrum that is not natural, hence harmful. Fig. 3.12 also indicates that photon emission is similar to any other radiation from a body of mass. This emission within the visible wavelengths is related to the existence of a flame. Even though a flame is typical of visible light emission, most recent theories indicate the presence of continuous emission throughout the entire spectrum. Light in the blue spectrum may also be a little stronger to allow the carotenes and xanthophylls to absorb more light as well. Fig. 3.13 shows the existence of these wavelengths in visible light.

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FIGURE 3.12 Number of particles versus particle size.

FIGURE 3.13 Colors and wavelengths of visible light.

Of importance in the above graph, Fig. 3.14 is the notion that artificial rays are harmful at all times. As the exposure is increased, the harm is accentuated. For the short term, artificial light visible light is less harmful than artificial nonvisible rays (e.g., gamma ray and X-ray) on both sides of the spectrum (both long wavelengths and short ones). The reason for such behavior has been discussed by Khan and Islam (2016) and will be discussed later in this section. The above graph follows the same form as the wavelength spectrum of visible sunlight (Figs. 3.12 and 3.15). Fig. 3.16 recasts visible colors on intensity of solar radiation for the visible light section. This figure confirms that green vegetation should be the most abundant color on earth for which the sun is the only natural source of energy. This figure also shows the area under

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FIGURE 3.14

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Artificial and natural lights affect natural material differently.

FIGURE 3.15 Wavelength spectrum of visible part of sunlight.

Intensity (counts)

4500 4000 3500 3000 2500 2000 1500 1000 500 0 400

450

500

550

600

650

700

750

Wavelength (nm)

the intensity
wavelength curve is the greatest for green materials. Red has longer wavelength but its intensity in sunlight is much smaller than green lights. If sunlight represents the original and the most beneficial energy source, any natural process emerging from sunlight will become beneficial. Such energy system is in harmony with water in its natural state.

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FIGURE 3.16 Visible natural colors as a function of various wavelengths and intensity of sunlight.

FIGURE 3.17

Typical frequency
response function.

3.2.7 Natural frequency of body parts In an effort to enhance the efficacy of the method, chest-resonance frequencies were measured on a sample of 23 volunteers. The average chest-resonance frequencies found for male and female healthy volunteers are 26.7 and 27.8 Hz, respectively. The results suggest that HFCCT should be carried out at about 18
34 Hz. Ideally, however, it is necessary to first obtain the chest-resonance frequency of the patient and then administer HFCCT at that value. This is because patients suffering from COPD will have impaired respiratory muscle and will have a smaller than normal chest-wall cavity, which in turn will affect the average chest-resonant frequency of patients suffering from COPD. A typical frequency
response function is shown in Fig. 3.17. Here, inertance is a measure of the pressure difference in a fluid required to cause a unit change in the rate of change of volumetric flow rate with time.

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Huang et al. (2017) reported a total of 400 broilers was divided into 5 treatment groups and stunned with 500, 600, 700, 800, and 900 Hz at 15 V for 10 seconds. Blood samples were collected immediately after cutting the neck. Pectoralis major muscles were removed from the carcass after chilling and placed in ice. Breast muscle pH and meat color were determined at both 2 and 24 hours postmortem. Drip loss, cooking loss, pressing loss, and cooked breast meat-shear values were determined at 24 hours postmortem. Treatment at 500 and 900 Hz significantly increased (P , .05) blood plasma corticosterone and lactate concentrations compared with the 700 Hz group. The wing damage of carcasses was significantly serious in the 500, 800, and 900 Hz groups. The Pectoralis minor damage of carcesses in the 700 Hz group was significantly lower (P , .05) compared to the other stunning groups. The pH at 2 hour postmortem in the 500 and 900 Hz groups was significantly lower (P , .05) than in other groups. However, the final pH and meat color were not affected by stunning frequency. In the 500 and 900 Hz groups, the protein solubility and shear force values were significantly lower (P , 0.05) and drip loss was significantly higher (P , .05) than in the 700 Hz group. This study indicates that the waveform of the pulsed direct current is acceptable for stunning broilers at a stunning frequency of 700 Hz. Results revealed that added salt had a major impact on dielectric properties and ΔT though no impact on thermal properties was noted. Fat had an influence on thermal properties and a lesser influence than salt on dielectric properties, though no significant effect (P $ .05) on ΔT was found across the range examined. The high inherent moisture content of the lean used made it difficult to isolate the impact of added water as increasing its addition level decreased the amount of added lean resulting in no net change in the moisture content across the range examined. Li et al. (2019) reported minimum time that requires to fully cook the yak meat using microwave with different power outputs, the cooking time ranged from 20 to 70 seconds were screened, and the organoleptic changes of yak meat were evaluated (Fig. 3.18). Raw yak meat samples were still bloody and not edible after cooking under high power (100%) for 20 and 25 seconds, and under medium (80%) for 30 and 40 seconds, under low (60%) for 50 and 60 seconds. Ultimately, longer microwave treatment times were selected for each power outputs: high (700 W) for 30, 40, 50, and 60 seconds; medium (560 W) for 50, 60, 70, and 80 seconds; low (420 W) for 70, 80, 90, and 100 seconds. Fig. 3.19 shows a crude overview in the form of a double logarithmic plot of the absorption coefficient of water from the microwave region (0.1 GHz) to the UV region (1016 Hz). Obviously, water shows a very pronounced increase of the absorption coefficient with frequencies extending into the IR region. This may even lead to α . 103 cm21, which corresponds to penetration depths δ of less than 10 μm. Between the vibrational excitations in the IR and the electronic excitations in the UV, there is the well-known minimum of α # 1023 cm21 in the visible, which leads to δ well above 10 m for clear water, that is, the high transmission of water experienced every day. Fig. 3.19 also explains why microwave ovens use a frequency of about 2.45 GHz rather than 20 to 1000 GHz, as may have been guessed from Fig. 5. With increasing frequency, α increases rapidly, that is, the penetration depth δ 5 1/α decreases rapidly. The food in microwave ovens has typical dimensions of the order of cm, and hence the penetration depth should be in this range. With a frequency of 20 GHz, the penetration depth would

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143 FIGURE 3.18 Effects of microwave treatments on organoleptic quality of yak meat.

be much smaller, that is the energy would be absorbed in a thin surface layer of the food (toasting the food) while the interior would remain cold. The lower frequency chosen results in absorption of the microwaves everywhere in the food. Therefore the surface will only get a brown crust if additional grilling facilities are available (Fig. 3.20). The natural frequencies of the normal and breast cancer cells of three different dimensions, namely, 30, 40, and 50 μm were computed. Natural frequencies of normal breast cells (MCF-10A) at these three dimensions showed no significant difference (P..05) between them. Similarly, for breast cancer cells (MCF-7), the difference in the natural frequencies for the three dimensions was insignificant. However, while comparing the normal with breast cancer cells, the natural frequency of normal cells (MCF-10A) was always higher than that of the MCF-7 cancerous cells (P , .05). Table 3.5 lists the mean natural frequencies of normal and breast cancer cells. The natural frequencies of the normal and prostate cancer cells of three different dimensions, namely 30, 40, and 50 μm were computed. Natural frequencies of normal prostate cells (BPH) at these three dimensions showed no significant difference (P..05) between them. Similarly, for breast cancer cells (MCF-7), the differences in the natural frequencies for the three dimensions were insignificant. However, while comparing the normal with prostate cancer cells, the natural frequency of normal cells (BPH) was always higher than that of LNCap cancerous cell (P , .05). Table 3.6 lists the mean natural frequencies of

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FIGURE 3.19 Absorption coefficient for water from microwaves to the UV.

normal and prostate cancer cells. Their modes of vibration are different at each natural frequency computed (Table 3.6). Since the frequency of normal and cancer cells is different, it is evident that mechanical properties of the cells such as their size, wall stiffness, and elasticity are the best signatures of cell status. The absolute measurement of these properties of biological systems is complex, and the simple comparison of two different oscillation frequencies would yield a better idea about the changes in the biological system (Zarandi, 2007). In his thesis, Zarandi (2007) conducted a finite element and experimental modal analysis to determine the mechanical properties of the living cells. Because the determination of mechanical properties of the living cells and particularly the natural frequencies are highly important to diagnose the health condition of cells, a comprehensive analysis is carried out to determine the natural frequencies of individual cells. Since many cells have a spherical shape, a spherical shape of the cell is considered for his analysis. The natural frequencies and corresponding mode shapes are determined for specific type of cell whose elastic properties of cell have been measured experimentally. To validate the numerical analysis, an experimental setup is designed to measure the natural frequencies of some scaled-up models of cell. In parallel, the numerical method that was used for cell modal analysis is employed to determine the natural frequencies of scaled-up models of cell to show the agreement between the finite element and experimental analyses.

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FIGURE 3.20 Dielectric constants of various kinds of food (Vollmer, 2004).

TABLE 3.5 Mean natural frequencies for normal and breast cancer cells. No. of modes (Hz)

n 5 1a

n 5 2a

n 5 3a

n 5 4a

n 5 5a

Natural frequency of normal breast cells

6.2579 6 2.2 14.516 6 1.18 17.071 6 1.29 261.40 6 2.8 1288.5 6 2.37

Natural frequency of cancerous breast cells 4.8369 6 1.9 11.212 6 1.13 13.195 6 1.34 202.4 6 3.18 995.96 6 2.78 Mean differences are significant for normal and breast cancer cells (P , .05). From Jaganathan et al. (2016).

a

TABLE 3.6 Mean natural frequencies for normal and prostate cancer cells. No. of modes (Hz)

n 5 1a

n 5 2a

Natural frequency of normal prostate cells

11.553 6 2.1 26.865 6 1.5 31.612 6 2.1

Natural frequency of cancerous prostate cells

8.6941 6 1.9 20.218 6 1.2 23.790 6 2.38 362.85 6 2.97 1783.5 6 2.23

Mean differences are significant for normal and prostate cancer cells (P , .05).

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n 5 3a

n 5 4a

n 5 5a

482.15 6 3.45 2369 6 1.86

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It turns out, in the presence of selected frequency operation, only cancer cells resonate and vibrate intensively leading to their selective destruction while sparing the normal cells. This can be related to a recent study, which demonstrates that the MCF-7 cells can be selectively killed under culture conditions using low-intensity ultrasonic irradiation at in silico-determined resonance frequencies (Geltmeier et al., 2015). Treatment options specifically targeting tumor cells are urgently needed in order to reduce the side effects accompanied by chemo- or radiotherapy. Differences in subcellular structure between tumor and normal cells determine their specific elasticity. These structural differences can be utilized by low-frequency ultrasound in order to specifically induce cytotoxicity of tumor cells. For further evaluation, we combined in silico FEM (finite element method) analyses and in vitro assays to bolster the significance of low-frequency ultrasound for tumor treatment. FEM simulations were able to calculate the first resonance frequency of MCF7 breast tumor cells at 21 kHz in contrast to 34 kHz for the MCF10A normal breast cells, which was due to the higher elasticity and larger size of MCF7 cells. For experimental validation of the in silico-determined resonance frequencies, equipment for ultrasonic irradiation with distinct frequencies was constructed. Differences for both cell lines in their response to low-frequent ultrasonic treatment were corroborated in 2D and in 3D cell culture assays. Treatment with B24.5 kHz induced the death of MCF7 cells and MDA-MB231 metastases cells possessing a similar elasticity; frequencies of .29 kHz resulted in cytotoxicity of MCF10A. Fractionated treatments by ultrasonic irradiation of suspension myeloid HL60 cells resulted in a significant decrease of viable cells, mostly significant after threefold irradiation in intervals of 3 hours. Most importantly in regard to a clinical application, combined ultrasonic treatment and chemotherapy with paclitaxel showed a significantly increased killing of MCF7 cells compared to both monotherapies. In summary, we were able to determine for the first time for different tumor cell lines a specific frequency of low-intensity ultrasound for induction of cell ablation. The cytotoxic effect of ultrasonic irradiation could be increased by either fractionated treatment or in combination with chemotherapy. Modal analysis indicates that the natural frequency obtained for normal cells is always higher than that of the cancer cells (both breast and prostate cancer cells) at each of the corresponding modes. Variation in cell dimension does not significantly alter the natural frequency of the cells. Modes of vibration of the cancer and normal cells show variation between them. Furthermore, the natural frequency increases with increasing Young’s modulus and density of the cells. In conclusion, the study shows that by exploiting the natural frequency of the cancer cells as a tool for treatment, the burden associated with chemotherapy and drug resistance may be overcome by specifically targeting the cancer cells. Next, we examined if fractionated treatments by ultrasonic irradiation might result in enhanced cytotoxicity. Since repeated trypsinization of adherent MCF7 cells was not feasible, we used the suspension myeloid cell line HL60 for which we determined 24.9 kHz as the most effective frequency for cell killing. Cells were treated by ultrasonic irradiation up to three times at intervals of 3 or 6 hours. The number of viable cells was determined 1 hour after each treatment. Even a singular treatment significantly reduced the number of viable cells to 60% (P 5 .0001) (Fig. 3.21). Repeated ultrasonic irradiation resulted in a further substantial decrease of viable cells, most significant after threefold irradiation in intervals of 3 hours (P 5 .02). Increasing the interval between two irradiations from 3 to 6 hours

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FIGURE 3.21 Decreased survival of HL60 cells after fractionated irradiation.

showed a trend toward increased cytotoxicity with only 43% or 31% viable cells, respectively. HL60 suspension cells were treated by ultrasonic irradiation once, twice or three times at intervals of 3 hours (2 3 3 hours, 3 3 3 hours) or 6 hours (2 3 6 hours). The number of vital cells was determined by FACS 1 hour after each irradiation. (The number of vital cells of the untreated control was set as 100%.) Results represent the means of data from three independent experiments; the error bars represent the standard errors; P-values were calculated by the two sided.

3.2.8 Disconnection of origins from process All science and social science theories have a common problem of disconnection between creation and creator as well as conflation between the traits of creator and creation. It then followed with disconnection of humanity from conscience, replacing conscience with a mechanical process, turning on the robotization process. Because engineering solutions were all based on this flawed science, they became extremely shortsighted without any long-term merit. Nonetheless, these solutions were adopted because of their economic appeal. Because of the fact that economic system itself is driven by the same premises of New science that led to the corruption of the entire process, a spiraldown mode became the only outcome of the entire technology development process. However, it was also promoted to be the only possible solution, without any alternative pathway to follow. Fig. 3.22 shows how both artificial and natural products (mass, energy, or human thought material [HTM]) act the same way except that their direction of movement is opposite to each other. Without tracking the time function, the description of material behavior has no meaning. This also shows how any natural material that cures an ailment cannot be substituted with an artificial chemical. Such artificial chemicals include all modern medicines, vaccines, antibiotic, and therapies for which nothing can be substituted for natural antidotes (e.g., cowpox, horse serum, fungus, and meditation) (Fig. 3.23). The essence of all exploration activities hinges upon the use of some form of wave that would depict subsurface structures. It is important to note that practically all such

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FIGURE 3.22 Natural artificial both act the same way, except for the time function.

FIGURE 3.23 Spiral-down process of policy and societal yin
yang that starts with disconnection of humans from conscience.

techniques use artificial waves, generated from sources of variable levels of radiation. Recently, Himpsel (2007) presented a correlation between the energy levels and the wavelength of photon energy (Fig. 3.24). It is shown that the energy level of photon decreases with the increase in wavelength. The sources that generate waves that penetrate deep inside the formation are more likely to be of high-energy level, hence more hazardous to the environment.

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FIGURE 3.24 Schematic of wavelength and

Photon Energy

energy level of photon. Source: From Islam et al. (2010).

10keV 1keV

0.1keV 0.01 keV Wave Length 0.1nm

1 nm

10 nm

100 nm

TABLE 3.7 Wavelength and quantum energy levels of different radiation sources. Radiation

Wavelength

Quantum energy

Infrared

1 mm
750 nm

0.0012
1.65 eV

Visible

750
400 nm

1.65
3.1 eV

Ultraviolet

400
10 nm

3.1
124 eV

X-rays

10 nm

124 eV

γ-rays

212

10

m

1 MeV

From Islam et al. (2015).

Table 3.7 lists the quantum energy level of various radiation sources. The γ-rays, which have the least wavelength, have the highest quantum energy levels. In terms of intensity, γ-rays have highest energy intensity among others. More energy is needed to produce this radiation whether to use for drilling or any other application. For instance, laser drilling, which is considered to be the wave of the future, will be inherently toxic to the environment.

3.2.9 Tangible/intangible conundrum or yin
yang cycle The failure that led to the current technological disaster is caused by failure in policies that govern our current society, in all scales, ranging from municipality to UN. How policies affect society, thereby setting in motion changes in the environment that later affect individuals that then engage in altering lifestyle and food consumption, can be explained by the yin
yang or tangible/intangible conundrum. All policies are based on dogmatic cognition and false theories and are motivated by short term, leading to “cancer” of the society. This causes collapse leading to environmental degradation that brings about human health degradation. Behavior of this negative yin
yang cycle is akin to cancer that deviates the footprint of organic DNA of the universal order.

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3.3 Atmospheric and vacuum distillation As discussed in previous chapters, the quality of crude oil received by the refineries varies widely. In addition, there has been a growing trend of heavier components being produced than in recent decades. This, in addition to the shortage of lighter oil globally, makes design criteria of refineries a formidable challenge. Vacuum distillation is distillation performed under reduced pressure, which allows the purification of compounds. Distillation is an important separation process that accounts for 90%
95% of all liquid separations and consumes .40% of energy in the chemical and refining industries (Humphrey and Siebert, 1992). To separate a multicomponent mixture containing n components into n pure products, a sequence of distillation columns known as a distillation configuration is required. The most common class of configurations, known as the regularcolumn configurations, use exactly (n 2 1) columns to separate an n-component mixture (Shenvi et al., 2012). The traditional refining process is based on the theory that petroleum is a homogenous molecular solution. It is assumed that the macrophase and composition of raw materials are only related to the properties of the solution, and only the relative volatility is considered, while the heterogeneity of petroleum is ignored. This assumption simplifies the mathematics behind the process. Different components are characterized based on their boiling points. This technique is used when the boiling point of the desired compound is difficult to achieve or will cause the compound to decompose. Reduced pressures decrease the boiling point of compounds. The reduction in boiling point can be calculated using a temperature
pressure nomograph using the Clausius
Clapeyron relation. The Clapeyron relation gives the slope of the tangents to this curve. The state function is assumed to be absolute, meaning P, V, and T together define the entire process, which is assumed to be in equilibrium and steady state. It is further assumed that dP=dT 5 L=ðTΔvÞ

(3.22)

where P is the pressure, T is the temperature, L is the specific latent heat, and Δv is the specific volume change of the phase transition. By invoking ideal gas law, the following form emerges:   (3.23) dP=dT 5 PL= RT 2 This equation is the most straight representation of the phase diagram, depicted in Fig. 3.25. This simplistic representation of the phase behavior has engineers devote themselves to improving the internal components of the unit, optimizing the operating conditions, improving the vacuum system, and adopting advanced control systems to improve the distillation efficiency and crude oil distillation extraction rate. However, that focus moves one away from the path of sustainability. To begin with, the potential for further improvement through those capital-intensive means is narrowing but all of these require large capital investment, and because these technologies are increasingly perfect and developed. The potential of using these means to increase the extraction rate is gradually decreasing.

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FIGURE 3.25 Conventional phase diagram.

3.3.1 Improving distillation Jiang et al. (2018a, 2018b) introduced “Heat mass integration (HMI) strategy” to intensify multicomponent distillation. They also provided methods for intensification in divided wall columns (DWC). They performed HMI on thermally coupled distillation columns, which largely reduced the number of columns required and also reduced heat requirements. HMI to consolidate distillation columns is one of the many ways to reduce the total cost of a configuration. One important aspect of HMI deals with introducing additional column sections. Such an HMI strategy is also referred to as HMI with additional sections, or simply HMA (Madenoor et al., 2015). One early example of HMA is shown in Fig. 3.26B (Brugma, 1942). In this figure, pure components are denoted by alphabets A, B, C, and so on, with volatilities decreasing in the same order. Streams with two or more components are called submixtures. Filled and unfilled circles in all figures denote condensers and reboilers, respectively. In the 4-component configuration of Fig. 3.26A, the pure product B produced at the reboiler of column 2 is more volatile than the pure product C produced at the condenser of column 3. Thus, instead of having two individual columns, HMA consolidates column 2 and column 3 into a single column with the introduction of an additional section. It subsequently removes the reboiler and the condenser associated with products B and C, respectively. Products B and C are now withdrawn from column 2
3 as side draws. Hence, the resulting heat and mass integrated configuration shown in Fig. 3.26B, also known as the Brugma configuration, use fewer heat exchangers and distillation columns. Also, since the vapor generated at the reboiler of column 2
3 is now utilized for both splits, AB-A/B and CD-C/D, the overall energy consumption reduces. The resulting capital and operating cost reduction make HMA attractive for many industrial applications. Also, notice that a DWC shown in Fig. 3.26C

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FIGURE 3.26 (A) A 4-component basic configuration; (B) Brugma configuration (Brugma, 1942); (C) DWC of Brugma configuration (Kaibel, 1987).

FIGURE 3.27 (A) A 6-component basic configuration; (B) heat and mass integrated configuration using 2HMAs; (C) the derived HMP configuration from (A).

can be derived from the Brugma configuration when thermal couplings are introduced at submixtures AB and CD before merging the two columns into a single shell (Kaibel, 1987). Of course, HMA is not limited to eliminating reboilers and condensers that produce pure product streams. In the 6-component configuration shown in Fig. 3.27A, the submixture BC produced at the reboiler of column 2 is more volatile than the submixture DE produced at the condenser of column 3. Likewise, column 4 produces the bottom product C which is lighter than D, the product produced at the top of column 5. Therefore, a series of new heat and mass integrated configurations can be derived. For example, one may consider consolidating columns 2 and 3 as well as columns 4 and 5 to form two new columns shown in Fig. 3.27B. Two intermediate column sections are added, and submixtures BC and DE as well as pure products C and D are all withdrawn as side draws from column 2
3 and column 4
5, respectively. Similarly, one may also consider consolidating only columns 2 and 3, or columns 4 and 5, or columns 2 and 5, and so on. Among the array of heat and mass integrated configurations that can be synthesized from Figure 2a, it turns out that the configuration shown in Fig. 3.27C will always have the lowest heat duty requirement. This configuration is obtained by first replacing all

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submixture heat exchangers with thermal couplings, followed by introducing HMA between the condenser at D and reboiler at C. To understand why this configuration is energy efficient, notice that the vapor generated at the reboiler of column 3, which is at the highest temperature level, is directed to progressively produce streams DE, D, C, BC, and B, which are at continuously decreasing temperature levels. Therefore, by sequentially degrading it to produce submixtures and pure products, this vapor has been utilized to its maximum potential. However, when HMA is directly introduced at submixtures as in Fig. 3.27B, the vapor generated at the reboiler of column 2
3 (reboiler F) is directly degraded to produce streams DE and BC without producing C and D. This implies less separation work accomplished by the vapor and greater irreversibility due to greater temperature difference between BC and DE. Thus, as a simple heuristic, HMA at submixture level should be avoided when vapor can flow freely across different distillation columns through thermal couplings, as in Fig. 3.27C at submixtures BC and DE. Configurations such as the one in Fig. 3.27C can be easily synthesized from the set of basic configurations, by first replacing all submixture heat exchangers with thermal couplings and then performing HMA only between pure components if possible. We refer to this new set of heat and mass integrated configurations as HMP configurations. Recently, Shah and Agrawal (2010) developed a simple-to-use algorithm, referred to as the SA method from hereon, to generate the complete search space of all basic distillation configurations. This powerful synthesis tool enables us to, for the first time, enumerate all HMP configurations. For each configuration generated by the SA method, we can determine if there simultaneously exists any pure product produced at a reboiler that is lighter than any pure product produced at a condenser. If so, this configuration is a candidate configuration for HMP. Table 3.8 summarizes the enumeration results for up to 6-component separations (Jiang et al., 2018a, 2018b). Note that the last column suggests that there exist multiple possible ways of introducing HMP for some candidate configurations. There has been some focus of research to try to find a material that can activate the crude oil system through the activation of crude oil to achieve the purpose of increasing the extraction rate, based on enhanced distillation technology. In the process of crude distillation, complex structural units are formed in the system, whose nuclei are associative colloids or bubbles, and their proportions depend on the properties and proportions of high and low molecular compounds in heavy oil. The natural surfactant in the material forms a solvation layer, which makes the dispersed phase and the dispersed medium in a relatively balanced state. The purpose of adding a fortifier when distilling crude oil is to change this equilibrium. Generally speaking, the composition of components in the system

TABLE 3.8 Enumeration of HMP configurations. n

Number of basic configurations

Number of candidate basic configurations for HMP

Number of HMP configurations

4

18

1

1

5

203

15

17

6

4373

282

347

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will not be in the best state (i.e., activation state), that is, will not be in the state of the highest gas-phase yield of distillation, additive enhanced crude distillation has great potential. From the point of view that petroleum is a colloid dispersion system, it is a convenient and economical method to increase the yield of light oil by adding intensifier and intensifying crude distillation in the process of petroleum processing. Intensified distillation with intensifier can improve the extraction rate, mainly because the intensifier changes the characteristics of residue dispersion system, so that the “complex structure unit” of associating colloid is in the extreme state with the smallest nuclear radius, shielding the effect of the adsorption force field of associating colloid. Wang (2019) introduced a new technology of intensifying crude distillation and improving light oil distillation with activator. This technology is based on “adjustable phase transition theory.” The mechanism of action of distillation intensifier can be divided into colloid structure mechanism, surface tension mechanism, and polymerization inhibition mechanism. In practice, it can be used to optimize or prepare activator with reasonable structure and good performance, and to control the size and physicochemical properties of “complex structural unit” to improve the yield of light oil. The mechanism of colloidal structure was developed on the basis of the theory developed by former Soviet Union researchers (Yang and Jia, 1992). The process can be improved by 1. Considering mechanism of heavy oil distillation process, with custom designed (including catalysts) process for each type of crude. 2. Adopting gradual gasification device with real boiling point distillation. 3. Minimize use of petroleum by-products as intensifying additives. The large amount of oil by-products (a few percent of the raw materials) increases the load of processing units, and brings about problems such as transportation and storage, and reduced unit capacity. Gasification produces energy from biomass and involves heating the biomass at elevated temperatures (above 1000 C) under a limited supply of oxygen to produce a mixture of gases (H2, CO, CO2) collectively referred to as syngas. However, the combustible constituents of the syngas are CO and H2 and can be used as fuel in gas engines for heat and electricity generation as well as for the production of chemicals (such as alcohols, organic acids, ammonia, and methanol) via the Fischer
Tropsch process. The Fischer
Tropsch process involves a series of chemical reactions that produce a variety of hydrocarbons, namely, alkanes, having the formula (CnH2n12), as expressed in the following reaction: ð2n 1 1ÞH2 1 n CO-Cn H2n12 1 n H2 O

(3.24)

Typically, n is 10
20. In a laboratory setting, the synthesis of hydrocarbon chains involves a repeated sequence in which hydrogen atoms are added to carbon and oxygen, the C
O bond is split and a new C
C bond is formed. For one
CH2
group produced by CO 1 2H2 - (CH2) 1 H2O, several reactions are necessary: • Associative adsorption of CO. • Splitting of the C
O bond. • Dissociative adsorption of 2 H2.

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• Transfer of 2H to the oxygen to yield H2O. • Desorption of H2O. • Transfer of 2H to the carbon to yield CH2. The process can be enhanced in presence of catalysts. Under laboratory conditions, most of the alkanes produced tend to be straight chain. In a natural setting, such straightchain molecules are rarely formed. Instead, complex hydrocarbon chains are formed, along with oxygenated hydrocarbons. In presence of high temperature and pressure, as prevalent in magma, similar reactions take place in presence of water and any carbon source, including limestone. Studies have shown that some volcanic minerals undergo catalysis and hydrogenation which can produce more oil and gas source rocks at lower temperature and pressure. A graphical representation of a gasification process, which depicts feedstock flexibility and the production of a wide range of products, is presented in Fig. 3.28. The key mechanism of the gasification technology involves the conversion of solid carbonaceous materials like biomass into flammable gas by partial oxidation. The chemistry involved in the process is quite complex and can be achieved via a series of physical and chemical transformation reactions that occur inside the gasification system. The major chemical reactions occurring are those that involve the degradation of large organic molecules into carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H2), water in the form

FIGURE 3.28 A schematic representation of a gasification process depicting feedstock flexibility and the wide range of products that can be obtained from the process. Source: From NETL (2021).

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of steam (H2O), and methane (CH4). These reactions take place in accordance with the chemical bonding theory and can be represented thus (Mohammadi and Anukam, 2022): The combustion reactions include   (3.25) C 1 1/2O2 -CO 2111 MJ=kmol   CO 1 1/2O2 -CO2 2283 MJ=kmol (3.26)   H2 1 1/2O2 -H2 O 2242 MJ=kmol (3.27)   H2 1 1/2O2 -H2 O 2242 MJ=kmol (3.28) Other key gasification reactions are as follows:   C 1 H2 O2CO 1 H2 1 131 MJ=kmol   C 1 CO2 22CO 1 172 MJ=kmol   C 1 2H2 2CH4 275 MJ=kmol

(3.29) (3.30) (3.31)

The above reactions occur under standard operating conditions of gasification and are considered important reactions that form the major part of the syngas produced in the gasification process. While Reaction (3.28) may be referred to as the “water
gas reaction,” Reactions (3.30) and (3.31) are termed the “Boudouard reaction” and the “methanation reaction” respectively. Reactions (3.30) and (3.31) are the main reduction reactions. However, under high carbon conversion conditions, Reactions (3.29)
(3.31), being heterogeneous in nature, are reduced to the following homogeneous gas-phase reactions:   (3.32) CO 1 H2 O2CO2 1 H2 241 MJ=kmol   CH4 1 H2 O2CO2 1 3H2 1 206 MJ=kmol (3.33) Reactions (3.32) and (3.33) are known respectively as the “water
gas-shift reaction” and the “steam
methane
reforming reaction.” These two reactions play a key role in determining the final equilibrium of the composition of the syngas produced in the gasification process. Under a limited supply of oxygen to the gasifier, the sulfur composition of the feedstock is converted to hydrogen sulfide (H2S), with a minute amount forming carbonyl sulfide (COS). The nitrogen (N) chemically bound in the feedstock is converted to gaseous nitrogen (N2), ammonia (NH3), and traces of hydrogen cyanide (HCN). The chlorine in the feedstock is mainly converted to hydrogen chloride (HCl). It is important to however state that the concentrations of sulfur, nitrogen, and chloride in the feedstock for gasification are sufficiently low that their effects in the gasification process are quite insignificant; trace elements (such as arsenic, mercury, and other heavy metals) that are associated with both the organic and inorganic components of the feedstock are mostly contained in the fractions of ash and slag formed during gasification, as well as in the gases emitted, and must be expunged from the syngas prior to further use. Wang (2019) identified the following protocols to strengthen the distillation process:

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1. Taking into account the surface activity and dispersion of strengthening agents. 2. Increasing the interfacial tension of colloidal structure and reducing the surface tension of bubbles. 3. Solving the compatibility of components. 4. Not affecting the performance of subsequent processing and final products. Theoretically, the optimum composition and molecular structure of intensified distillation additives can be designed by determining the chemical composition, physical composition, or various physical and chemical macroscopic properties of distillation raw materials and conducting molecular or colloid thermodynamic calculations. Up to now, the main types of distillation intensifiers have been used as follows: 1. Aromatic hydrocarbon concentrates, such as lube base oil refining extracts, cracking tars, catalytic cracking and refining oils, slurries, furfural extracts and other components rich in aromatic hydrocarbons. 2. Surface active substances, such as C12
C14 and C16
C20 higher fatty alcohols, synthetic fats, and fatty acids. 3. Composite activator, such as aromatic hydrocarbon concentrate with trace phenol or polymer and silicone oil mixture. 4. Synthesis of polymer. The addition of distillation intensifier in crude oil can counteract the excess surface tension and release low molecular hydrocarbons from the system, which is activated. However, the amount of reinforcement is limited, and the excessive addition will lead to the association of the reinforcement molecules and reduce the extraction rate of crude oil. Ding et al. (2016) reported an effective process intensification technique by combining microwaves with classical reactive distillation (RD). They experimented with microwaveassisted reactive distillation (MRD) for esterification reaction between acetic acid and ethanol in the presence of sulfuric acid as a catalyst. This technique improved reaction time and improved the product purity. Their main agenda of using microwaves were its property to increase the relative volatility of mixture components. They studied the effects of reflux ratio, ethanol to acetic acid mole ratio, reboiler duty, microwave power on conversion, and purity of the product. With an increase in the reflux ratio, they found the purity of the product to be increased for RR 5 2 to 4 and then decreased for RR 5 4 to 5. At RR 5 6 purity of the product was again increased which was because of an increase in residence time of ethanol. They also discovered the rapid increase in conversion and product purity with an increase in reboiler duty, which was because of the high vaporization of ethanol in the liquid phase of the reaction zone. The conversion of ethanol and product purity was found to decrease with an increase in microwave power. Wierschem et al. (2017) experimented with one of the most efficient process intensification techniques on RD. They focused on utilization of ultrasound on enzymatic reactive distillation (ERD). ERD is a bioreactive process in which enzymes are immobilized on the internal surface of the column to overcome chemical reaction and phase equilibrium conditions. Ultrasound was used to activate these enzymes. This method was tested for the synthesis of ethyl butyrate (EtBu) by transesterification reaction with BuOH yielding BuBu as the main product. The enzymatic catalyst, lipase B from yeast candida Antarctica, was

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FIGURE 3.29 Scheme of the US-ERD process with the enzyme-coated packing placed in the US-assisted reactive section.

immobilized in a thin film on the surface of structured packing used for conventional distillation. When Ultrasound was used, the conversion of reactants was 1.6% more than the conventional ERD method. Also, the purity of BuBu obtained was approximately 99%. They justified the cost of ultrasound-ERD column with 12% less reactive section height and 7% lower total height of the column compared to the conventional ERD column. The synergies between Ultrasound irradiation and ERD are now brought together in an integrated setup. Hence, this work is the first to propose an ultrasound-assisted enzymatic reactive distillation (US-ERD) process. A techno-economic evaluation and optimization of the US-ERD process are performed, which is then compared against the optimized ERD process in which enzyme-coated packing is solely used (no US). The comprehensive mathematical model of ERD was previously developed to describe the mass transfer, packing properties, and the catalyst kinetics (Wierschem et al., 2016b), which was used by Wierschem et al. (2017). Fig. 3.29 illustrates the proposed configuration for the US-ERD process. The capacity considered in that study is 10 kiloton per year (ktpy) product 17 stream of BuBu (99 wt.% purity), obtained by transesterification of EtBu with BuOH and yielding to ethanol (EtOH) as co-product (Eq., 3.34). EtBu 1 BuOH"BuBu 1 EtOH

(3.34)

The enzymatic catalyst, lipase B from the yeast Candida antarctica (CalB) is known as an efficient and robust enzyme catalyzing several organic reactions, including transesterification. Within ERD, the enzymes are immobilized in a thin film, coated on the surface of

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FIGURE 3.30

159 Manipulated variables of the

optimization.

structured packing that is usually used for conventional distillation. It is also possible to immobilize enzymes in form of enzyme beads, but there was no effect of US on enzyme activity observed for this type of immobilization (Wierschem et al., 2017). Fig. 3.30 shows the optimized version of the scheme. The total feed stream (mFeed, tot) and the substrate ratio (χFeed) are set free and therefore the bottom stream (mBottom) and the bottom mass fraction (wEtBu) are fixed. The reboiler and condenser duties (QReb and QCond) are free variables, whereas the reflux ratio (RR) and the distillate-to-feed-ratio (D/F) are fixed and manipulated within the optimization. Harvianto et al. (2017) studied hybrid process combining thermally coupled RD with membrane-based pervaporation. They used the process for enhancing the production of nbutyl acetate from n-butanol and methyl acetate. They found that this hybrid technique improved the energy efficiency of RD process by preventing remixing effect and nullifying the azeotropic nature of methanol (product) and methyl acetate in the recycle stream. This method reduced reboiler duty by 63% and annual cost by 43% when compared to conventional RD. This method proved to be advantageous in cases of low feed rate, high methanol concentration in the liquid split stream, low methanol concentration in rectifying stages, and high conversion in RD. In order to exploit all the benefits of the designs, this work proposes a combination of both, that is, thermally coupled RD with pervaporation (TCRD 1 PV). Fig. 3.31 shows the proposed TCRD 1 PV configuration compared with the existing RD 1 PV and TCRD configurations. In the proposed TCRD 1 PV configuration, the reactive distillation column is thermally coupled to the side-stripper column, and nearly pure methyl acetate is fully

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MeAc+MeOH

MeAc

MeAc PV MC BuOH

MeAc+MeOH

MeOH+MeAc

RDC Reaction Zone

PV

MeOH

MeAc

RD+PV

RDC BuOH Reaction Zone

BUAc

Retrofit MeAc+MeOH

MeAc

SS

MeOH+MeAc

MeOH BuAc BuOH MeAC

RDC Reaction Zone

SS

TCRD

TCRD+PV MeOH BuAc

FIGURE 3.31

Proposed system for thermally coupled reactive distillation with pervaporation (TCRD 1 PV).

TABLE 3.9 Summary of available pervaporation membranes for methanol
methyl acetate separation at the same feed composition (20 wt.% of methanol). Membrane

Temp. ( C)

Total flux (kg/m2h)

Permeate (wt.% methanol)

Separation factor

Cuprophane

45

0.453

66.5

7.9

Pervap 2255
40

45

4.125

42.0

2.9

Pervap 2255
50

45

1.375

56.4

5.2

Pervap 2255
60

45

0.65

58.7

5.7

Pervap 2255
30

40

2.44

54.4

4.8

PolyAl TypM1

44

8.1

34.5

2.6

recovered as the retentate from pervaporation and fed back to the RD column. To solve the methanol
methyl acetate azeotrope problem in the distillate stream of the RD column, this work uses a commercial per vaporation membrane owing to its market availability. This intensified design is expected to reduce both operating and capital costs. The separation performances of numerous different commercial membranes have been evaluated for this system in several research works dealing with pervaporation of methanol
methyl acetate mixtures (Gorri et al., 2006). Table 3.9 summarizes the currently

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available commercial pervaporation membranes that can be used for this system. A high concentration of methanol can be obtained in the permeate stream using these methanolselective membranes. Table 1 also compares the performance of each membrane for the same feed specification. The feed used for comparison is an azeotropic methanol
methyl acetate mixture (20 wt.% or 36 mol.% of methanol). Spasojevic et al. intensified the distillation process by providing a new approach to minimize entropy production across the column. In traditional approach, adiabatic columns were used which require condensers and reboilers for heat exchange. However, they used the technique of diabatic distillation in which heat is introduced in stripping and removed from the rectifying section. Heat exchange is independent for each tray and does not require heat exchangers. In conventional method, heat to be exchanged on trays depend upon was based on temperature on trays. Rather than temperature, they used the quantity of heat to be exchanged as control variables for minimizing the entropy production. This procedure was tested for the separation process of benzene and toluene feed mixture each consisting of 0.5 mole fraction. The minimum value for produced entropy in the diabatic column was 1.056 J/s K, while for the adiabatic column, the entropy produced was 2.998 J/s K. By this method, they saved around 64.77% of energy requirements. Simple adiabatic binary column with ideal trays and total con denser, shown in Fig. 3.32, serves for binary mixture separation and includes feed mixture (F) and two products—distillate (D) and bottom products (B). The column is equipped with a condenser at the top (total) and boiler at the bottom. An analogous diabatic column with the exchanger at every tray is shown. Although a reflux into the column does not come back from the condenser at the top, it serves only for vapor condensation from the top into distillate. FIGURE 3.32 total condenser.

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Kiss et al. (2019) carried out process intensification on RD by combining it with other intensive distillation technologies such as DWC, heat integrated distillation, and cyclic distillation. Reactive divided wall columns increased production yield to a great extent by simultaneously saving 15%
70% of energy usage and decreasing capital costs by 20% when compared to classical DWC techniques. They added solid catalysts on trays bringing in the new technique of catalytic cyclic distillation (CCD). Helium catalysts helped in controlling the liquid flow rate and reaction time. This technique increased the quality of the product and reduced the energy requirements (Figs. 3.33 and 3.34). Taking RD to the next level of process intensification requires more advanced configurations, which extend the range (and overlap) of operating conditions beyond those applicable to classical RD. Other variations of RD may include, for example, integration with other PI technologies, use of different operating modes, or membrane-, or microwave-, or ultrasound-assisted RD for further energy savings, high efficiency, and environmental friendliness. RD in a dividing-wall column (DWC) was a logical next step waiting to be developed in academia and applied industrially. Literature reports range from rate-based modeling and simulation of R-DWC processes to broad analysis of the reactive dividing-wall column, its minimum energy demand and the potential for energy savings, and more recently, a comprehensive review on R-DWC. R-DWC has been modeled using rate-based approaches, and the performance of R-DWC units has been theoretically studied for different chemical systems. Some research groups investigated R-DWC using standard routines available in commercial process simulators (e.g., Aspen Plus), but experimental investigations of R-DWC configurations are still very scarce. The advantages demonstrated by this highly integrated process, in both modeling and experimental studies, are high conversion, increased selectivity, and product purity, significant energy, and cost savings. FIGURE 3.33

RD requires an overlap of the operating windows for reaction and separation. The star symbols illustrate cases where standalone separation and reaction are preferred, while the plus indicates a match for RD (Kiss et al., 2019).

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FIGURE 3.34

Summary of improvements proposed by Kiss et al. (2019).

FIGURE 3.35

Reactive dividing-wall column: generic configuration (left) and specific setup for DME synthesis (right).

Fig. 3.35 illustrates the typical configuration of a generic R-DWC, as well as an application to the dimethyl ether (DME) process. R-DWC applications have been reported (mostly as simulation studies) for the production of various chemicals, for example, methyl acetate, ethyl acetate, dimethyl ether, fatty acid methyl esters (FAME), biodieseldiethyl carbonate, n-propyl propionate, and other industrial applications. R-DWC technology has been an active area of research during the past decade, with many studies concluding that the technology is industrially feasible and ready for implementation at commercial scales. The main challenges to the commercialization of R-DWC are the lack of experimental results (currently limited to only five chemical systems, two lab-scale and two industrial scale units), uncertainties in R-DWC modeling and simulation, lack of demonstration of (complex) control schemes (e.g., model predictive control), need for improvement of dynamic models, and shortcut design. Nonetheless, R-DWC technology can add significant value to new chemical processes, with a strong potential to improve production yields, to save 15%
75% in energy usage and over 20% in capital cost, as compared to conventional processes. The design and control of R-DWC can draw on the extensive experience of RD and DWC, respectively. The key limitations of R-DWC relate to catalyst formulation, hold-up and residence time, pressure drop and flooding,

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LIQUID

LIQUID STRUCTURED PACKING

(REACTION ZONE)

VAPOR

VAPOR

CATALYST

MALETA TRAY

MALETA TRAY VAPOR VAPOR

FIGURE 3.36

Cyclic distillation.

and the need for equal pressure drop on the two sides of the dividing wall. The main potential applications are reversible reactions where the components have suitable boiling point characteristics (i.e., that allow separation while also being suitable for the reaction). Cyclic distillation is a new contender in fluid separations, providing an innovative way of creating contact between the liquid and vapor phases. Unlike conventional operation, cyclic distillation uses separate phase movement (SPM) that can be achieved with technology-specific internals and a periodic operation mode. One operating cycle consists of two key parts: a vapor flow period (when the thrust of rising vapor prevents liquid downflow) followed by a liquid flow period (when the liquid flows down the column, dropping by gravity from one tray to the tray below). This cyclic mode of operation leads to key advantages, compared to conventional trayed columns: high throughput and equipment productivity, high separation efficiencies (140%
200% Murphree efficiency), reduced energy requirements (20%
35% savings), and increased quality of the products. The pilot scale implementation of the cyclic distillation technology available at Maleta cyclic distillation is expected to be valuable for demonstration of technology readiness. Adding a catalyst on the trays leads to catalytic cyclic distillation (CCD) that is a novel process intensification approach in reactive separations. Fig. 3.36 illustrates the typical internals used for cyclic distillation. Such a setup allows control of the amount of liquid on the tray and thus the reaction time. As the liquid holdup and the amount of catalyst per tray can be significantly greater than in conventional RD systems, applications to slower reactions become feasible as well, thus extending the range of applicability of RD.

3.3.2 Optimization of the distillation process Shah and Agrawal (2010) proposed a new matrix-based method to generate the search space of all basic configurations for any number of components in the feed of a distillation process. It is quite simple and can be easily used for higher number of components in the feed. In this method, we write variables in a matrix form to use physical insights in the problem that help to simplify the problem. The method can easily incorporate

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the additional configurations with thermal coupling in the search space. It is also useful for other network synthesis problems involving nondistillation separation devices. The matrix method is a six-step method to generate the complete search space of basic distillation configurations for any n-component zeotropic feed mixture containing components A, B, C, etc. In this mixture, A is the most volatile component and volatility decreases sequentially in alphabetical order. Let us first observe that for a given feed stream, only certain product streams can be derived from the top and bottom of a distillation column. For instance, a stream BCDE can lead to only stream BCD, BC, or B as the top product and stream CDE, DE, or E as the bottom product. For this to hold true, we have assumed that in a distillation column, any product stream has at least one less component than the feed stream. Recall that in our nomenclature, when a stream like BC is produced from BCDE, it does not necessarily mean that D and E are totally absent from BC, but when present, their concentrations are acceptably small and they eventually show up as acceptable impurities in the “pure” product streams B and C from further distillation of BC. 3.3.2.1 Step 1 The first step of our method is to identify the predominant number of components that need to be separated as product streams from a feed stream. This is available from the problem definition and is the only information needed to generate the complete search space. For instance, if one is given a five-component feed to be separated into five pure products each enriched in one of the components, one can identify the predominant number of components as n 5 5. 3.3.2.2 Step 2 The second step is to generate an n 3 n upper triangular matrix. For the current example case of the five-component feed mixture, it implies generation of a 5 3 5 matrix. In the matrix, all the elements below the diagonal are assigned a value of zero (i.e., xi, 5 0 ’i. j) and all the elements in the upper triangular part correspond to unique streams. j Suppose the components are numbered in decreasing order of their volatility, that is, let A 5 component number 1, B 5 component number 2, and so on. In any row “i” of the matrix, for all j $ i, let the first component of the stream corresponding to each element in that row be component number “i.” Also, in any column “j” of the matrix, let the number of components in the stream corresponding to each element of that column be “n 1 1 2 j” for i # j. Hence, the following equations emerge: First component for mixtures in row ‘‘i’’ 5 Component ‘‘i’’ 0

Number of components for mixtures in column ‘j 5 n 1 1
j

(3.35) (3.36)

Therefore, to obtain the stream corresponding to any (i,j), one can calculate the number of components in the mixture using n 1 1 2 j, and then write the ith component first followed by subsequent heavier components till the total number of components in that mixture is included. For instance, in Fig. 3.37, when (row, column) 5 (3,4), then row 5 3 implies that the mixture will contain component number 3, that is, component C, as the lightest component, and column 5 4 implies that the mixture has two components

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FIGURE 3.37

3. Fundamentals of processing

Matrix for a five-component feed mixture.

FIGURE 3.38

Identification of the “d” submixtures in a matrix.

(since 5 1 1 2 4 5 2). As the next heaviest component is D, the mixture corresponding to the third row and the fourth column is binary mixture CD. Therefore, for the fivecomponent feed stream, one thus gets the streams ABCDE, ABCD, BCDE, ABC, BCD, CDE, AB, BC, CD, DE, A, B, C, D, and E at the locations shown in Fig. 3.37. This is a simple way of generating all feasible mixtures given the number of components in the feed. Listing the streams in this manner within the matrix helps us apply physical insights. If one chooses any stream in the matrix, except the final products, and move horizontally to the right, all the streams that we encounter on this path are candidate top products from the distillation of the chosen stream. When one moves diagonally down and to the right, all the streams that one encounters on this path are candidate bottom distillation products. The streams that are not encountered cannot be top and bottom products of the chosen stream. Similarly, once one picks any stream, except the main feed, and move horizontally to the left, or diagonally up and to the left, all the streams that one encounters on these paths are candidate feeds which upon distillation can produce the picked product stream. No other stream that is not on these paths can produce the picked product stream. For instance, in Fig. 3.38, if one starts from stream BCD and move horizontally to the right, we can identify streams BC and B as candidate top products. Similarly, if we move diagonally down and to the right, one can identify streams CD and D as candidate bottom products. Finally, one ends up with an n 3 n upper triangular matrix with favorable properties that have physical interpretations. 3.3.2.3 Step 3 The next step is to classify an element of the matrix as corresponding to either the main feed stream, a submixture stream, or a final product stream. The equation that gives the number of submixture streams is as follows:   nðn 1 1Þ 2n21 (3.37) d5 2

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For instance, for the matrix shown in Fig. 3.37, we have 5(5 1 1)/2 2 5 2 1 5 9 submixtures in columns 2 to 4, namely streams ABCD, BCDE, ABC, BCD, CDE, AB, BC, CD, and DE, in addition to the main feed stream ABCDE in column 1 and the final product streams in column 5. These streams are boxed in Fig. 3.38. In a given distillation configuration, not all the possible submixtures are necessarily transferred between distillation columns. For example, there are d 5 3(3 1 1)/2 2 3 2 1 5 2 submixtures, namely AB and BC, for a three-component feed. These three configurations all have the main feed stream and the final product streams. They are different only because they transfer different submixtures. The presence or absence of such transfer submixture streams thus uniquely defines a basic distillation configuration. This is the basic principle behind the matrix method. Hence, assume that a unique matrix corresponds to a unique basic distillation configuration. Also assume the presence of submixtures in this matrix only if the submixtures are transferred from one distillation column to another in a distillation configuration. Therefore, in the next few steps, we will provide an easy mathematical framework to indicate the presence of only certain submixtures in a matrix so that we obtain a corresponding basic configuration. 3.3.2.4 Step 4 In the fourth step, we create matrices representing all possible combinations of the presence and absence of submixtures. We first assign binary integer values (0 or 1) to each element in the upper triangular portion of the matrix. If the element of the matrix takes a value of 1, it implies that the corresponding stream is present in the distillation configuration; if the element takes a value of 0, it implies that the corresponding stream is absent in the configuration. The presence or absence of a stream refers to its occurrence outside the distillation columns of the configuration. The presence of a stream means it is either a submixture which is transferred between distillation columns, or it is the main feed stream, or it is one of the final product streams. However, in any distillation configuration, the main feed stream and the n-product streams (i.e., the (1,1) element and all the elements in the nth column of the matrix) have to exist. Therefore, those binary integer variables are forced to take a value of 1. We are left with “d” degrees of freedom from Eq. 3.43, which could take values of 0 or 1 and these correspond to the submixtures (like those boxed in Fig. 3.38). Therefore, we have to generate and examine 2d 0
1 upper triangular matrices, each of which corresponds to a candidate basic configuration. Many of these matrices are physically infeasible; the others correspond to feasible basic distillation configurations, and together they form the complete search space. 3.3.2.5 Step 5 In the fifth step, we want to eliminate physically infeasible configurations from the 2dcandidates. To do this, we use two physical facts: (1) except the main feed stream, any stream that exists in a distillation configuration must be produced by another stream and (2) in the absence of chemical reactions, all components that enter a distillation column must also leave the distillation column. However, for our 2d matrices, we actually implement three checks:

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3.3.2.5.1 Check 1

For every stream that exists in a matrix (except the main feed stream), ensure that at least one corresponding stream that can act as its feed also exists within the matrix. 3.3.2.5.2 Check 2

Disallow physically impossible splits (for instance, a split-like BCDE forming B and DE, which is not allowed because C has disappeared in the split). 3.3.2.5.3 Check 3

Ensure that at least n 2 2 submixtures are transferred. Each distillation column must necessarily have a top and a bottom product, while it may or may not have some sidedraw product streams. Each distillation column thus has at least two product streams. We have a minimum of 2(n 2 1) product streams in a configuration, of which n are final product streams. This gives us the minimum number of intermediate product streams (or submixtures) as 2(n 2 1) 2 n 5 (n 2 2). In fact, the configurations that have exactly (n 2 2) out of the maximum possible “d” submixtures being transferred are the sharp-split configurations. It is clearly not possible to have a feasible basic distillation configuration that transfers less than (n 2 2) submixture streams. The three checks can be easily implemented in a computer program for any n-component mixture because of the favorable properties of the matrix representation. Let xi,j 5 0/1 be the binary variables associated with the (i,j)th elements of the matrix. We shall now develop mathematical constraints to implement these physical checks. Suppose we want to apply Check 1 for the (p,q)th element of the matrix. The check should of course be enforced only if the (p,q)th element has a binary value of 1 (i.e., the corresponding submixture is transferred between distillation columns in the configuration). Therefore, if xp,q 5 1, we must ensure that it is formed from at least one feasible feed—at least one of the (p,q)th element’s candidate feed streams should also have a binary value of 1. Recall that the candidate feed streams of the (p,q)th stream can lie only on paths horizontally to the left and diagonally up and to the left from the (p,q)th element of the matrix. At least one of the binary variables on these paths must have a value of 1, so the first check simply results in the following equation: q21 X

j5p p 6¼ q

xp;j 1

p21 X

xi;i 1 q 2 p $ xp;q ’q . 1; ’q . 1; ’p # q

(3.38)

i51 p 6¼ 1

In Eq. 3.38, the first summation term on the LHS is the sum of all the binary variables on a horizontal path to the left of the (p,q)th element. For this term, p 6¼ q ensures that we do not move in the lower triangular portion of the matrix. The second summation term on the LHS is the sum of all the binary variables on a diagonal path moving up and to the left of the (p,q)th element. Here, p 6¼ 1 ensures that we do not move out of the matrix. If the RHS, xp,q, takes a value of 0, all these LHS binary variables are free to be either 0 or 1, and the constraint does nothing to ensure the presence of the candidate feed streams.

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This is desired, as we do not need to ensure presence of feeds for a product stream that does not exist in the configuration. On the other hand, if the RHS takes a value of 1, at least one of the binary variables on the LHS is forced to take a value of 1, thereby ensuring that at least one of the feasible feed streams exists to produce the (p,q)th stream under consideration. Obviously, this constraint is not applied to the main feed stream, thereby giving us q . 1. Also, it is applied for all other streams in the matrix, but with p # q, to disregard elements of the matrix below the diagonal which have been assigned values of 0 while generating the n 3 n matrix. Eq. 4 thus provides a mathematical constraint for applying Check 1. Next, for applying Check 3, we use the following constraint: j n21 X X

$ ð n 2 2Þ

(3.39)

j52 i51

Here, the LHS involves all the “d” binary variables corresponding to the submixture streams, and the inequality ensures that at least (n 2 2) of these submixture streams are transferred. Therefore, Checks 1 and 3 result in simple linear inequality constraints. It is not as straightforward to obtain such constraints for Check 2, but Check 2 can still be implemented easily because of the matrix representation of a configuration. To implement Check 2, we start from the main feed stream (in column 1 of the matrix) and go up to all the ternary streams (in column n 2 2 of the matrix). This is because there is never disappearance of components in the distillation of any binary stream as all the final products are always present in any configuration. Therefore, we systematically apply Check 2 to all the elements that have values of 1, in the upper triangular portion of columns 1 through (n 2 2) of the matrix. If an element located in say column j
and thus containing (n 1 1 2 j) components as seen from Eq. 3.36—has a binary value of 1, then from that element we march horizontally to the right and diagonally down to the right, until we hit the next “1” on each path. These are respectively identified as the top and bottom product of the stream we started from, as all preceding streams, if any, on these horizontal and diagonal paths have binary values of 0, thereby implying that they do not exist outside distillation columns in the distillation configuration. The respective matrix column locations j1 and j2 of these products give us the number of components in the top and bottom products as (n 1 1 2 j1) and (n 1 1 2 j2). The sum of these should be at least as much as the number of components (n 1 1 2 j) in the stream under consideration. Check 2 can be implemented in other ways as well. One possible alternative is to identify the first component of the top and bottom products as component number i1 and component number i2, respectively. This can be done by identifying the rows of the matrix in which these elements are located. The last component of the top product will then be the component number:   i 1 5 i1 1 n 1 1 2 j1 2 1 5 ði1 1 n 2 j1 Þ (3.40) One then obtain ði2 2 i 1 # 1 1 n 2 j1 Þ as the constraint to ensure Check 2. If this difference exactly equals 1, it can easily be seen that it corresponds to a sharp split (i.e., no overlapping components); if the difference is 0, then we have one overlapping component; if the difference is 21, then we have two overlapping components, and so on. Obviously, if the difference is greater than 1, it implies disappearance of components.

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Check 2 can be converted to linear inequality constraints like Eqs. (3.44) and (3.45) corresponding to Checks 1 and 3, but this would require some additional binary decision variables and some additional linear constraints. Instead of Checks 1 and 2, which are sufficient to obtain feasible configurations, one can also use any other checks as long as they perform the job of filtering out the infeasible candidate configurations. We presented Checks 1 and 2 because they have simple physical interpretations and their implementation can be easily automated, even though they may not be the strongest set of equations for a mixed integer nonlinear programming problem (MINLP) formulation to find the optimum configuration. Any candidate matrix that satisfies all the checks is retained as a feasible basic distillation configuration. All other candidate matrices are discarded. Once we apply these checks for each of the 2d candidate matrices, we are left with all feasible basic distillation configurations, each of which is obtained in the form of a 0
1 upper triangular matrix. However, we can also use the following alternative to obtain all the feasible basic distillation configurations: we generate linear inequality constraints corresponding to Checks 1, 2, and 3 and reformulate the problem as an integer programming (IP) problem, which can be solved to give a feasible solution (a basic distillation configuration). This basic configuration will now correspond to a vector of decision variables instead of a matrix of decision variables. We can then add a cut (a linear constraint) to eliminate this solution (configuration) and resolve the IP problem to arrive at another feasible solution. We can keep repeating this until there are no more feasible solutions. However, it is much faster and simpler to enumerate all the 2d candidate matrices and quickly apply our checks to each. The equations and procedure corresponding to the checks may look complicated, but they are just mathematical expressions of intuitive steps. Let us illustrate the use of all the steps of the method so far by generating a complete search space of basic configurations for a threecomponent feed. Although this is a simple case, the use of the checks should become clear. Step 1 assigns n 5 3 for the three-component feed stream. In Step 2, we declare a 3 3 3 matrix with all elements assigned zeros below the diagonal. For each of the remaining elements corresponding to say (i,j) with i # j, we can easily calculate the first component using Eq. 3.35, and the number of components of each element using Eq. 3.36, to obtain a description of the stream corresponding to that element. For example, for the element (1,1), the first component as given by Eq. 3.35 is component number 1, that is, A, and the number of components as given by Eq. 3.36 is 3 1 1 2 1 5 3. The stream corresponding to this element is stream ABC. We can repeat this procedure for each element to give us the matrix shown in Fig. 3.39. Step 3 makes us identify the two submixtures boxed in Fig. 3.40 (since from Eq. 3.37, we get d 5 3(3 1 1)/2 2 3 2 1 5 2). These elements of the matrix can thus take values of either 0 or 1. The other four elements are forced to take values of 1 as they correspond to the main feed stream and the three final product streams. Then, as per Step 4, we generate the 2d 5 22 5 4 candidate matrices shown in Fig. 3.40. Step 5 involves implementing the checks to eliminate infeasible configurations. Check 1 is to be applied for all the elements except the (1,1) element corresponding to the main feed stream. Applying Eq. 3.38 for the (1,2) element, we obtain: p 5 1; q 5 2-x1;1 $ x1;2

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FIGURE 3.39

Matrix for a three-component feed mixture. Submixtures

are boxed.

FIGURE 3.40 matrices mixture.

for

a

The 2d 5 4 candidate three-component feed

which ensures a feed for the (1,2) element if it exists. Physically, it ensures that if stream AB is present in the configuration, then stream ABC, which is the only possible feed of stream AB, must also be present in the configuration. Similarly, we get p 5 2; q 5 2-x1;1 $ x2;2

(3.41b)

p 5 1; q 5 3-x1;1 1 x1;2 $ x1;3

(3.41c)

p 5 2; q 5 3-x2;2 1 x1;2 $ x2;3

(3.41d)

p 5 3; q 5 3-x1;1 1 x2;2 $ x3;3

(3.41e)

Eq. (3.41b) ensures that if stream BC is present in the configuration, then stream ABC, which again, is the only possible feed of stream BC, must also be present in the configuration. The LHS of Eq. (3.41a) comes from the first term on the LHS of Eq. (3.41), which corresponds to horizontal movement to the left, and the second term of Eq. (3.41) which corresponds to diagonal movement up and to the left makes no contribution. Also, the LHS of Eq. (3.41b) comes from the second term on the LHS of Eq. (3.41) (diagonal movement) with the first term of Eq. (3.41) (horizontal movement) making no contribution. Eqs. (3.41a) and (3.41b) thus apply Check 1 to both the elements (p 5 1 and p 5 2) of column q 5 2. Similarly, Eqs. (3.41c), (3.41d), and (3.41e) correspond to the three elements of the third column of the matrix: streams A, B, and C, respectively. For stream A, Eq. (3.41c) ensures that at least one of the streams ABC or AB is present. The terms on the LHS of Eq. (3.41c) correspond to horizontal movement, and there are no terms corresponding to diagonal movement, as there is no movement possible diagonally up and to the left of the (1,3) element. In the general n-component case, such an equation for the lightest final product will always be redundant as the main feed stream is always present, thereby always ensuring the presence of a feasible feed stream. Next, Eq. 4e ensures that at least one of streams ABC or BC is present, to produce stream C, as stream C can be produced by no other stream. These terms on the LHS of Eq. (3.41e) correspond to diagonal movement, as now there is no movement possible

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horizontally. Once again, such an equation for the heaviest final product will also always be redundant. In fact, we will also obtain redundant equations for any submixture that contains the lightest component or the heaviest component of any n-component mixture, because the presence of the main feed stream always guarantees a feasible feed for any such submixture. Simply stated, we need not apply Check 1 for all the elements located in the first row of the matrix and in the diagonal of the matrix. For stream B, Eq. (3.41d) ensures that at least one of streams BC or AB must be present in the configuration. Note that there are no other streams that can produce stream B. Stream BC corresponds to the first term on the LHS of Eq. (3.41), and it arises due to horizontal movement to the left from stream B. Similarly, stream AB corresponds to the second term on the LHS of Eq. (3.41), and it arises due to diagonal movement up and to the left from stream B. The matrices of Fig. 3.40B
D satisfy all Eqs. (3.38
3.41e), whereas the matrix of Fig. 3.40A violates Eq. (3.41d). Therefore the matrix of Fig. 3.40A corresponds to an infeasible candidate configuration and can be eliminated. This is because in this candidate configuration, none of the candidate feed streams (AB or BC) is present to form B. Ideally, once a candidate matrix does not satisfy any equation, we can discard it straightaway without applying any further equations to it. On the other hand, in order to be a basic configuration, a matrix must satisfy all the equations and checks. In this case, further equations and checks only need to be applied to the matrices of Figures 7b
d. However, to illustrate their use, we will still apply all the other equations and checks to all the candidate matrices. Check 2 involves starting from column 1 of the matrix and proceeding till column (n 2 2) 5 1 (in this case). For feeds that have more than three components, we would have to consider more columns of the matrix, and not just the first column like in this example. Here, we apply Check 2 only for the single element present in column 1. This (1,1) element has a value of 1, so as per Check 2, we move horizontally to the right until we encounter the next 1. This gives us the top product. Similarly, we move diagonally to the right and identify the bottom product. Therefore, for the matrix of Figure 7a, elements (1,3) and (3,3) are identified as the products. They both have 3 1 1
3 5 1 component each, as obtained from Eq. (3.42). The sum of their number of components is 2, which is lesser than the number of components in the (1,1) element of the matrix (as it has 3 1 1 2 1 5 3 components as obtained from Eq. 3.42 again). Hence, the matrix of Fig. 3.40A is once more identified as being infeasible, but this time because component B does not appear in either the distillate and the bottom product stream in spite of being present in the feed stream, and it has thus “disappeared” during the split. Simply stated, here ABC has split to A and C, which is physically impossible. If we repeat this procedure with the remaining matrices, we find that they correspond to feasible configurations. This concludes the application of Checks 1 and 2. The matrices of Fig. 3.40B
D are thus the complete set of basic configurations for a three-component feed. Let us now illustrate the use of Check 3 to quickly eliminate infeasible configurations. Check 3 provides us with x1,2 1 x2,2 $ 1, which just states that we should have at least (n 2 2) 5 1 submixture. Hence, the inequality ensures that at least one of the submixture streams AB or BC must be present in the configuration. Once again, we see that the matrix

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of Figure 7a is infeasible, whereas the other three are feasible. The first two checks are in fact sufficient for obtaining feasible configurations, but this third check always provides us with a single simple inequality constraint, which can eliminate some of the infeasible configurations without even having to go through the first two checks. 3.3.2.6 Step 6 Now we have a feasible set of 0
1 upper triangular matrices representing the search space for basic distillation configurations. From these 0
1 matrices, we can easily deduce all the information necessary to “draw” a configuration, and this will be the sixth and the final step of our method. Step 6 simply provides a user of the method or an optimization solver with the locations of the various splits in the (n 2 1) distillation columns of a basic configuration. The procedure to do this is as follows: (1) replace the 1 second in the matrix by the corresponding streams, (2) identify all the splits in the matrix, (3) stack the splits appropriately in distillation columns, and (4) assign distillation column numbers. Consider the matrix shown in Fig. 3.41A. After replacing the 0
1 elements by the appropriate streams, we get the matrix shown in Fig. 3.41B. We then start from the

FIGURE 3.41 (A) A feasible 0
1 matrix; (B) replacing 0
1s by appropriate streams in the matrix of Figure 8a; (C) Listing all possible splits and then grouping the splits that belong to the same distillation column; (D) assigning distillation column numbers.

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main feed stream ABCDE, and move horizontally to the right, and identify stream ABCD as the top product (this is the next “1” on a horizontal path), and we move diagonally down to the right and similarly identify BCDE as the bottom product. Therefore, the first split is ABCDE
ABCD/BCDE. We repeat the procedure with stream ABCD and get the second split as ABCD
ABC/BCD. Similarly, we also get the following splits: BCDE
BCD/CDE, ABC
AB/BC, BCD
BC/CD, CDE
CD/DE, AB
A/B, BC
B/C, CD
C/D, and DE
D/E. These splits are depicted in Fig. 3.41C. Note that we are depicting these splits as pseudo-distillation columns. Here, we do not allow a stream to be formed as the top product from two different streams or as the bottom product from two different streams. This implicitly avoids generating nonbasic configurations. Next note that splits which make a common stream (product) must belong to the same distillation column to have a basic configuration that uses exactly (n 2 1) distillation columns. These common streams are withdrawn as side draws, and their associated reboilers and condensers are eliminated. Hence, splits ABCD
ABC/BCD and BCDE
BCD/ CDE belong to the same distillation column as they both make BCD, which will be produced as a sidedraw. Similarly, splits ABC
AB/BC and BCD
BC/CD belong to the same distillation column as they both make BC, and split CDE
CD/DE also belongs to this distillation column as it makes CD in common with the split BCD
BC/CD. In the same way, splits AB
A/B, BC
B/C, CD
C/D, and DE
D/E belong to the same distillation column. These groupings are illustrated by the boxes in Fig. 3.41C. A consequence of this procedure is that to produce any stream on a horizontal path to the right, we must use a condenser. Similarly, to produce any stream on a diagonal path to the right, we must use a reboiler. Further, if the stream is produced by both a reboiler and a condenser, the reboiler and condenser are eliminated and the stream is then produced as a sidedraw. Finally, we assign distillation column numbers to the splits. Therefore, split ABCDE
ABCD/BCDE belongs to, say, “distillation column 1” shown in Fig. 3.41D, splits ABCD
ABC/BCD and BCDE
BCD/CDE both belong to, say, “distillation column 2” of Fig. 3.41D, splits ABC
AB/BC, BCD
BC/CD, and CDE
CD/DE all belong to “distillation column 3,” and finally splits AB
A/B, BC
B/C, CD
C/D, and DE
D/E all belong to “distillation column 4” of Fig. 3.41D; we thus obtain the completed distillation configuration shown in Fig. 3.40D. In this way, any 0
1 matrix can be converted easily to a distillation configuration figure. Within a distillation column that contains more than one split, a split whose feed has a lighter first component must be placed above a split whose feed has a heavier first component. Similarly, we can obtain the distillation configurations of Fig. 2 from the matrices of Figs. 3.40B
D. Finally, the method can be easily modified to obtain search spaces that contain special types of basic configurations only, as dictated by physical needs of an actual problem. For example, to obtain only the sharp splits, the inequality of Eq. (3.41) is replaced by an equality. Consider another example. If for a five-component feed ABCDE, say component C needs to be produced from a condenser. Such a requirement may be necessary if the purity of product C needs to be strictly controlled. Then, we can add equations that assign submixtures ABC and BC as both 0, that is, x1,3 5 x2,4 5 0.

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3.4 Refining and gas processing Petroleum refineries change crude oil into petroleum products for use as fuels for transportation, heating, paving roads, and generating electricity and as feedstocks for making chemicals. Refining breaks crude oil down into its various components, which are then selectively reconfigured into new products. Petroleum refineries are complex and expensive industrial facilities. All refineries have three basic steps: • Separation • Conversion • Treatment • Separation Modern separation involves piping crude oil through hot furnaces. The resulting liquids and vapors are discharged into distillation units. All refineries have atmospheric distillation units, while more complex refineries may have vacuum distillation units (Fig. 3.42). Inside the distillation units, the liquids and vapors separate into petroleum components called fractions according to their boiling points. Heavy fractions are on the bottom and light fractions are on the top. The lightest fractions, including gasoline and liquefied refinery gases, vaporize and rise to the top of the distillation tower, where they condense back to liquids.

FIGURE 3.42 Diagram of a refinery distillation column and major products produced (EIA, 2022a, 2022b, 2022c).

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Medium weight liquids, including kerosene and distillates, stay in the middle of the distillation tower. Heavier liquids, called gas oils, separate lower down in the distillation tower, while the heaviest fractions with the highest boiling points settle at the bottom of the tower. • Conversion After distillation, heavy, lower-value distillation fractions can be processed further into lighter, higher-value products such as gasoline. This is where fractions from the distillation units are transformed into streams (intermediate components) that eventually become finished products. The most widely used conversion method is called cracking because it uses heat, pressure, catalysts, and sometimes hydrogen to crack heavy hydrocarbon molecules into lighter ones. A cracking unit consists of one or more tall, thick-walled, rocketshaped reactors and a network of furnaces, heat exchangers, and other vessels. Complex refineries may have one or more types of crackers, including fluid catalytic cracking units and hydrocracking/hydrocracker units. Cracking is not the only form of crude oil conversion. Other refinery processes rearrange molecules to add value rather than splitting molecules. • Treatment The finishing touches occur during the final treatment. To make gasoline, refinery technicians carefully combine a variety of streams from the processing units. Octane level, vapor pressure ratings, and other special considerations determine the gasoline blend.

3.4.1 Pathways of crude oil formation Crude oil is a naturally occurring liquid found in formations in the Earth consisting of a complex mixture of hydrocarbons consisting of various lengths. It contains mainly four groups of hydrocarbons among, which saturated hydrocarbon consists of straight chain of carbon atoms, aromatics consists of ring chains, asphaltenes consists of complex polycyclic hydrocarbons with complicated carbon rings and other compounds mostly are of nitrogen, sulfur, and oxygen. It is believed that crude oil and natural gas are the products of huge overburden pressure and heating of organic materials over millions of years. Crude oil and natural gases are formed as a result of the compression and heating of ancient organic materials over a long period of time. Oil, gas, and coal are formed from the remains of zooplankton, algae, terrestrial plants and other organic matters after exposure to heavy pressure and temperature of Earth. These organic materials are chemically changed to kerogen. With more heat and pressure along with bacterial activities, oil and gas are formed. Fig. 3.43 is the pathway of crude oil and gas formation. These processes are all driven by natural forces.

3.4.2 Pathways of oil refining Fossil fuels derived from the petroleum reservoirs are refined in order to suit the various application purposes from car fuels to aeroplane and space fuels. It is a complex

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Biomass

FIGURE 3.43

Crude oil formation pathway. Source: After Chhetri and Islam (2008).

Decay and degradation Natural processes

Burial inside earth and ocean floors for millions of years Kerogen formation Bacterial action, heat, and pressure Bitumen, crude oil and gas formation

Crude oil storage and transportation

Vacuum distillation Atmospheric distillation

FIGURE 3.44

General activities in oil refining (Chhetri and Islam, 2007).

Hydrocarbon separation Cracking, Coking etc. Hydrocarbon creation

Alkylation, reforming etc.

Hydrocarbons blending

Removal of sulfur other chemicals

Cleaning impurities

Solvent dewaxing, caustic washing

mixture of hydrocarbons varying in composition depending on its source. Depending on the number of carbon atoms the molecules contain and their arrangement, the hydrocarbons in the crude oil have different boiling points. In order to take the advantage of the difference in boiling point of different components in the mixture, fractional distillation is used to separate the hydrocarbons from the crude oil. Fig. 3.44 shows general activities involved in oil refining. Petroleum refining begins with the distillation, or fractionation of crude oils into separate hydrocarbon groups. The resultant products of petroleum are directly related to the properties of the crude processed. Most of the distillation products are further processed into more conventionally usable products changing the size and structure of the carbon chain through several processes by cracking, reforming and other conversion processes. In order to remove the impurities in the products and improve the quality, extraction, hydrotreating and sweetening are applied. Hence, an integrated refinery consists of fractionation, conversion, treatment, and blending including petrochemicals processing units. Oil refining involves the use of different types of acid catalysts along with high heat and pressure (Fig. 3.45). The process of employing the breaking of hydrocarbon molecules

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Crude Oil

Boiler Super-heated steam

Heat, pressure, acid catalysts

Cracking Thermal/Catalytic

H2SO4, HF, AlCl3, Al2O3, Pt as catalysts

Alkylation

Platinum, nickel, tungsten, palladium

Hydro processing

High heat/pressure

Distillation

Distillation Column

FIGURE 3.45 Pathway of oil refining process. Source: After Chhetri and Islam (2007).

Other methods

TABLE 3.10 Emission from a Refinery (Environmental Defense, 2005). Activities

Emission

Material transfer and storage

• Air release: Volatile organic compounds • Hazardous solid wastes: anthracene, benzene, 1,3-butadiene, curnene, cyclohexane, ethylbenzene, ethylene, methanol, naphthalene, phenol, PAHs, propylene, toluene, 1,2,4-trimethylbenzene, xylene • Air release: Carbon monoxide, nitrogen oxides, particulate matters, sulfur dioxide, VOCs • Hazardous solid waste: ammonia, anthracene, benzene, 1,3-butadiene, curnene, cyclohexane, ethylbenzene, ethylene, methanol, naphthalene, phenol, PAHs, propylene, toluene, 1,2,4-trimethylbenzene, xylene

Separating hydrocarbons

is the thermal cracking. During alkylation, sulfuric acids, hydrogen fluorides, aluminum chlorides, and platinum are used as catalysts. Platinum, nickel, tungsten, palladium, and other catalysts are used during hydro processing. In distillation, high heat and pressure are used as catalysts. The use of these highly toxic chemicals and catalysts creates several environmental problems. Their use will contaminate the air, water, and land in different ways. Use of such chemicals is not a sustainable option. The pathway analysis shows that current oil refining process is inherently unsustainable. Refining petroleum products emits several hazardous air toxins and particulate materials. They are produced while transferring and storage of materials and during hydrocarbon separations. Table 3.10 lists the emission released during the hydrocarbon separation process and handling. Table 3.11 shows the primary waste generated from an oil refinery. In all processes, air toxics and hazardous solid materials, including volatile organic compounds are present. There are various sources of emissions in the petroleum refining and petrochemical industries, and the following are the major categories of emission sources (US EPA, 2008).

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TABLE 3.11

Primary wastes from oil refinery (Environmental Defense, 2005).

Cracking/coking

Alkylation and reforming

Sulfur removal

Air releases: carbon monoxide, nitrogen, oxides, particulate matter, sulfur, dioxide, VOCs

Air releases: carbon monoxide, nitrogen oxides, particulate matter, sulfur dioxide, VOCs

Air releases: carbon monoxide, nitrogen oxides, particulate, matter, sulfur dioxide, VOCs

Hazardous/solid wastes, wastewater, ammonia, anthracene, benzene, 1,3-butadiene, copper, cumene, cyclohexane, ethylbenzene, ethylene, methanol, naphthalene, nickel, phenol, PAHs, propylene, toluene, 1,2,4-trimethylbenzene, vanadium (fumes and dust), xylene

Hazardous/solid wastes: ammonia, benzene, phenol, propylene, sulfuric acid aerosols or hydrofluoric acid, toluene, xylene Wastewater

Hazardous/solid wastes: ammonia, diethanolamine, phenol, metals, wastewater

3.4.2.1 Process emissions In petroleum refining and petrochemical industries, the typical processes that take place include separations, conversions, and treating processes, such as cracking, reforming, and isomerization. The emissions arising from these processes are termed as process emissions, and are typically released from process vents, sampling points, safety valve releases, and similar items. 3.4.2.2 Combustion emissions Combustion emissions are generated from the burning of fuels, which is done for production and transportation purposes. The nature and quantity of emissions depend upon the kind of fuel being used. Generally, combustion emissions are released from stationary fuel combustion sources such as furnaces, heaters, and steam boilers, but they can also be released from flares, which are used intermittently for controlled release of hazardous materials during process upsets. 3.4.2.3 Fugitive emissions Fugitive emissions include sudden leaks of vapors from equipment or pipelines, as well as continuous small leaks from seals on equipment. These emissions are not released from vents and flares but may occur at any location within a facility. Sources of fugitive emissions are mostly valves, pump and compressor, and piping flanges. Fugitive emissions are a source of growing concern, as their effective control requires good process safety mechanisms for mitigation, as well as ongoing lead detection and repair programs. 3.4.2.4 Storage and handling emissions These emissions are released from the storing and handling natural gas, oil, and its derivatives. This is a potential problem in every petroleum refining and petrochemical industry, including any product distribution sites. Handling mainly includes loading and unloading operations for shipping products to customers. Though transport of many refinery products is through pipelines, some other means like marine vessels and trucks also exist. In these cases, there might be emissions during material transfer to these vehicles.

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3.4.2.5 Auxiliary emissions Auxiliary emissions originate from units like cooling towers, boilers, sulfur recovery units, and wastewater treatment units. Atmospheric emissions from cooling towers mainly include gases, which are stripped when the water phase comes into contact with air during the cooling process. In wastewater treatment units, emissions may arise by stripping of the VOCs from contaminated wastewater in the pond, pits, drains, or aeration basins.

3.4.3 Pathways of gas processing Natural gas is a mixture of methane, ethane, propane, butane and other hydrocarbons, water vapor, oil and condensates, hydrogen sulfides, carbon dioxide, nitrogen, some other gases, and solid particles. The free water and water vapors are corrosive to the transportation equipment. Hydrates can plug the gas accessories creating several flow problems. Other gas mixtures such as hydrogen sulfide and carbon dioxide are known to lower the heating value of natural gas by reducing its overall fuel efficiency. There are certain restrictions imposed on major transportation pipelines on the make-up of the natural gas that is allowed into the pipeline called pipe “line quality” gas. This makes mandatory that natural gas be purified before it is sent to transportation pipelines. The gas processing is aimed at preventing corrosion, environmental and safety hazards associated with transport of natural gas. The presence of water in natural gas creates several problems. Liquid water and natural gas can form solid ice-like hydrates that can plug valves and fittings in the pipeline (Nallinson, 2004). Natural gas containing liquid water is corrosive, especially if it contains carbon dioxide and hydrogen sulfide. Water vapor in natural gas transport systems may condense causing a sluggish flow. Hence, the removal of free water, water vapors, and condensates is a very important step during gas processing. Other impurities of natural gas such as carbon dioxide and hydrogen sulfide generally called as acid gases must be removed from the natural gas prior to its transportation (Chakma, 1999). Hydrogen sulfide is a toxic and corrosive gas, which is rapidly oxidized to form sulfur dioxide in the atmosphere (Basu et al., 2004). Oxides of nitrogen found in traces in the natural gas may cause ozone layer depletion and global warming. Fig. 3.46 illustrates the pathway of natural gas processing from reservoir to end uses. This figure also shows various emissions from natural gas processing from different steps. After the exploration and production, natural gas stream is sent through the processing systems. Fig. 3.47 is the schematic of general gas processing system. Glycol dehydration is used for water removal from the natural gas stream. Similarly, methanolamines (MEA) and diethanolamine (DEA) are used for removing H2S and CO2 from the gas streams (Fig. 3.47). Since these chemicals are used for gas processing, it is impossible to completely free the gas from these chemicals. Glycols and amines are very toxic chemicals. Burning of ethylene glycols produces carbon monoxide (Matsuoka et al., 2005) and when the natural gas is burned in the stoves, it is possible that the emission produces carbon monoxide. Carbon monoxide is a poisonous gas and very harmful for the health and environment. Similarly, amines are also toxic chemicals and burning the gas contaminated by amines produces toxic emissions. Despite the prevalent notion that natural gas burning is clean, the emission is not free from environmental problems. It is reported that one of the highly

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Natural gas reservoirs

Exploration and Production

High process heat, glycol, amines and other catalysts

Residential (Cooking)

Emission through venting, flaring

gas “well-to-wheel” pathway.

Emission, wet seals, flaring

Processing/purification

Transportation

Emission from engines, pumps and leaks

Storage and distribution

Emission from gates, pipes, meters and leaks

(End-uses)

Exhaust emission, unburnt, particulates emission etc.

Commercial

FIGURE 3.46 Natural

Electricity production

Transport

Industrial

Natural gas processing Remove sand and large particles

Oil and condensate removal Low Temperature Separator (use of temp-pressure differential)

Water removal

Separation of natural gas liquids

Adsorption

Glycol Dehydration Diethylene glycol (DEG), Triethylene glycol (TEG)

Adsorption

H2S removal

Use of absorbing oil or fractionating

Activated alumina or a granular silica gel

CO2 Removal

Monoethanolami ne (MEA) and Diethanolamine (DEA)

- Bulk removal by hollow fibre polymer membranes. - DEA, MDEA absorption

FIGURE 3.47 Natural gas processing methods. Source: Redrawn from Chhetri and Islam (2006).

toxic compounds released in natural gas stoves burning (LPG in stoves) is isobutane which causes hypoxia in the human body (Sugie et al., 2004). 3.4.3.1 Pathways of glycol and amines Conventional natural gas processing process consists of applications of various types of chemicals and polymeric membranes. These are all synthetic products that are derived

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from petroleum sources but after a series of denaturing. The common chemicals used to remove water, CO2 and H2S are diethylene glycol (DEG) and triethylene glycol (TEG) and monoethanolamines (MEA), diethanolamines (DEA) and triethanolamine (TEA). These are synthetic chemicals and have various health and environmental impacts. Synthetic polymers used as membrane during gas processing are highly toxic and their production involves using highly toxic catalysts, chemicals, excessive heat and pressures (Islam et al., 2010). Hull et al. (2002) reported combustion toxicity of ethylene-vinyl acetate (EVA) copolymer reported higher yield of CO and several volatile compounds along with CO2. Islam et al. (2010) reported that the oxidation of polymers produces more than 4000 toxic chemicals, 80 of which are known carcinogens. Matsuoka et al. (2005) reported a study on electro oxidation of methanol and glycol and found that electro-oxidation of ethylene glycol at 400 mV forms glycolate, oxalate, and formate (Fig. 3.48). The glycolate was obtained by three-electron oxidation of ethylene glycol and was an electrochemically active product even at 400 mV, which led to the further oxidation of glycolate. Oxalate was found stable, no further oxidation was seen and was termed as nonpoisoning path. The other product of glycol oxidation is called formate which is termed as poisoning path or CO poisoning path. The glycolate formation decreased from 40%
18% and formate increased from 15%
20% between 400 and 500 mV. Thus, ethylene glycol oxidation produced CO instead of CO2 and follows the poisoning path over 500 mV. The glycol oxidation produces glycol aldehyde as intermediate products. Hence, use of these products in refining will have several impacts in the end uses, and are not sustainable at all. Glycol ethers are known to produce toxic metabolites such as the teratogenic methoxyacetic acid during biodegradation, the biological treatment of glycol ethers can be hazardous (Fischer and Hahn, 2005). Abiotic degradation experiments with ethylene glycol showed that the by-products are monoethylether (EGME) and toxic aldehydes, for example, methoxy acetaldehyde (MALD). Glycol passes into body by inhalation, ingestion, or skin. Toxicity of ethylene glycol causes depression and kidney damage (MSDS, 2005). High concentration levels can interfere with the ability of the blood to carry oxygen causing headache and a blue color to the skin and lips (methemoglobinemia), collapse, and even death. High exposure may affect the nervous system and may damage the red blood cells leading to anemia (low blood count). During a study of carcinogenetic and toxicity of propylene glycol on animals, the skin tumor incidence was observed (CERHR, 2003). Glycol may form toxic alcohol inside human body if ingested as fermentation may take place. FIGURE 3.48

Ethylene glycol oxidation pathway in alkaline solution (After Matsuoka et al., 2005).

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Amines are considered to be toxic chemicals. It was reported that occupational asthma was found in people handling of a cutting fluid containing diethanolamine (Piipari et al., 1998). Toninello et al. (2006) reported that the oxidation products of some biogenic amines appear to be also carcinogenic. DEA also reversibly inhibits phosphatidylcholine synthesis by blocking choline uptake (Lehman-McKeeman and Gamsky, 1999). Systemic toxicity occurs in many tissue types including the nervous system, liver, kidney, and blood system that may cause increased blood pressure, diuresis, salivation, and pupillary dilation. Diethanolamine causes mild skin irritation to the rabbit at concentrations above 5%, and severe ocular irritation at concentrations above 50% (Beyer et al., 1983). Ingestion of diethylamine causes severe gastrointestinal pain, vomiting, and diarrhea, and may result in perforation of the stomach possibly due to the oxidation products and fermentation products.

3.5 Sustainable development 3.5.1 Petroleum refining and conventional catalysts Crude oil is always refined in order to create value-added products. Refining translates directly into value addition. However, the refining process also involves cost-intensive usage of catalysts. Catalysts act as denaturing agent. Such denaturing creates products that are also unnatural and for them to be useful special provisions have to be made. For instance, vehicle engines are designed to run with gasoline, aircraft engines with kerosene, diesel engines with diesel, etc. In the modern era, there have been few attempts to use crude oil in its natural state, and the main innovations have been in the topic of enhancing performance with denatured fluids. Consequently, any economic calculations presume that these are the only means of technology development and make any possibility of alternate design invariably unsuitable for economic considerations. Catalysis started to play a major role in every aspect of chemical engineering beginning with the 20th century, in sync with plastic revolution. Today, more than 95% of chemicals produced commercially are processed with at least one catalytic step. These chemicals include the food industry. Fig. 3.49 shows the introduction of major industrial catalytic processes as a function of time. Even though it appears that catalysis is a mature technology, new catalysts continue to be developed. The focus now has become on developing catalysts that are more efficient and muffle the toxicity. World catalysis sales accounted for $7.4 billion in 1997 and today it is estimated to be over $20 billion in 2018. The processing and refining industry depends exclusively on the use of catalysts that themselves are extracted from natural minerals through a series of unsustainable processing, each step involving rendering a material more toxic while creating profit for the manufacturer. The following operations, mostly involving hydroprocessing applications, use numerous catalysts: • • • • •

Tail gas treating. Alkylation pretreatment. Paraffin isomerization. Xylene isomerization. Naphtha reforming (fixed and moving bed).

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FIGURE 3.49 Summary of the historical development of the major industrial catalytic processes per decade in the 20th century. Source: From Islam et al. (2018).

• • • • • • • • • •

Gasoline desulfurization. Naphtha hydrotreating. Distillate hydrotreating. Fluidized catalytic cracking pretreatment. Hydrocracking pretreatment. Hydrocracking. Lubricant production (hydrocracking, hydrofinishing, and dewaxing). Fixed and ebullated-bed residue hydrotreating. Catalyst-bed grading products. Process description.

Each of these processes involves selection of proprietary reactor internals that are part of conventional design optimization. The entire optimization takes place after fixing the chemicals to be used during the refining process. As pointed out by Rhodes (1991) decades ago, there are thousands of chemicals involved in numerous processes. Some examples are as follows: • • • • • • • • • • • • •

Catalytic naphtha reforming. Dimerization, isomerization (C4). Isomerization (C5 and C6). Isomerization (xylenes). Fluid catalytic cracking (FCC). Hydrocracking, mild hydrocracking. Hydrotreating/hydrogenation/saturation. Hydrorefining. Polymerization. Sulfur (elemental) recovery. Steam hydrocarbon reforming. Sweetening. Claus unit tail gas treatment.

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• Oxygenates. • Combustion promoters (FCC). • Sulfur oxides reduction (FCC). Yet, each step of the refining process is remarkably simple and can work effectively without the addition of natural material in their natural state (without extraction of toxic chemicals). The distillation of crude oil into various fractions will give naphtha as a fraction which ranges from C5 to 160 degrees (initial to final boiling point). This fraction is further treated to remove sulfur, nitrogen, and oxygen, which is commonly known as “hydrotreating” and rearranged for improving octane number which can be done by “continuous catalytic reforming (for heavy naphtha which starts from C7)” or “isomerization” (for light naphtha which contains only C6 and C7 molecules) and after that blended for desired spec (BS-III, BS-IV or euro IV, euro V, etc.) and sold in market as gasoline through gas stations.

3.5.2 Catalytic cracking Cracking is the name given to breaking up large hydrocarbon molecules into smaller and more useful bits. This is achieved by using high pressures and temperatures without a catalyst, or lower temperatures and pressures in the presence of a catalyst. The source of the large hydrocarbon molecules is often the naphtha fraction or the gas oil fraction from the fractional distillation of crude oil (petroleum). These fractions are obtained from the distillation process as liquids but are revaporized before cracking. The hydrocarbons are mixed with a very fine catalyst powder. As the efficiency is inversely proportional to the grain size, such powder forms are deemed necessary. For this stage, zeolites (natural aluminosilicates) that are more efficient than the older mixtures of aluminum oxide and silicon dioxide can render the process move toward sustainability. For decades, it has been known that zeolites can be effective catalysts (Turkevich and Ono, 1969). The whole mixture is blown rather like a liquid through a reaction chamber at a temperature of about 500C. Because the mixture behaves like a liquid, this is known as fluid catalytic cracking (or fluidized catalytic cracking). Although the mixture of gas and fine solid behaves as a liquid, this is nevertheless an example of heterogeneous catalysis—the catalyst is in a different phase from the reactants. The catalyst is recovered afterward, and the cracked mixture is separated by cooling and further fractional distillation. There is not a single unique reaction taking place in the cracker. The hydrocarbon molecules are broken up random way to produce mixtures of smaller hydrocarbons, some of which have carbon
carbon double bonds. C15 H32 - 2C2 H4 1 C3 H6 1 C8 H18 Catalyst ethane

propane

octane

This is only one way in which this particular molecule might break up. The ethene and propene are important materials for making plastics or producing other organic chemicals. The octane is one of the molecules found in gasoline. A high-octane gasoline fetches height value in the retail market.

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3.5.3 Isomerization Hydrocarbons used in petrol (gasoline) are given an octane rating which relates to how effectively they perform in the engine. A hydrocarbon with a high octane rating burns more smoothly than one with a low octane rating. Molecules with “straight chains” have a tendency to preignition. When the fuel/air mixture is compressed it tends to explode and then explode a second time when the spark is passed through them. This double explosion produces knocking in the engine. Octane ratings are based on a scale on which heptane is given a rating of 0, and 2,2,4trimethylpentane (an isomer of octane) a rating of 100. In order to raise the octane rating of the molecules found in gasoline to enhance the combustion efficiency in an engine, the chemical branch of oil industry rearranges straight-chain molecules into their isomers with branched chains. One process uses a platinum catalyst on a zeolite base at a temperature of about 250 C and a pressure of 13
30 atmospheres. It is used particularly to change straight chains containing 5 or 6 carbon atoms into their branched isomers. The problem here, of course, is that platinum is highly toxic to the environment in its pure form (after mineral processing). The same result can be achieved by using platinum ore and making adjustment to the volume of the reactor. Because platinum ore is natural, it would be free from the toxicity of pure platinum. It is also possible that there are other alternatives to platinum ore—a subject that has to be researched.

3.5.4 Reforming Reforming is another process used to improve the octane rating of hydrocarbons to be used in gasoline. It is also a useful source of aromatic compounds for the chemical industry. Aromatic compounds are ones based on a benzene ring. Once again, reforming uses a platinum catalyst suspended on aluminum oxide together with various promoters to make the catalyst more efficient. The original molecules are passed as vapors over the solid catalyst at a temperature of about 500 C. This process has two levels of toxic addition that has to be corrected. The first one is platinum and the second one is aluminum oxide and its related promoters. We have already seen how zeolite contains aluminum silicate that can replace aluminum oxide. In addition, other natural materials are available that can replace aluminum oxide. Isomerization reactions occur but, in addition, chain molecules get converted into rings with the loss of hydrogen. Hexane, for example, gets converted into benzene, and heptane into methylbenzene. The overall picture of conventional refining and how it can be transformed is shown in Fig. 3.50. The economics of this transition is reflected in the fact that the profit made through conventional refining would be directly channeled into reduced cost of operation. This figure amounts to the depiction of a paradigm shift. The task of reverting to natural from unnatural has to be performed for each stage involved in the petroleum refining sector. Table 3.12 lists various processes involved and the different derivatives produced. Note that each of the products later becomes a seed for further use in all aspects of our lifestyle. As a consequence, any fundamental shift from unsustainable to sustainable would reverberate globally.

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FIGURE 3.50 Natural chemicals can turn a sustainable process into a sustainable process while preserving similar efficiency.

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TABLE 3.12 Overview of petroleum refining processes (U.S. Department of Labour, n.d.). Process name

Action

Method

Purpose

Feedstock(s)

Product(s)

Fractionation processes Atmospheric distillation

Separation

Thermal

Separate fractions Desalted crude oil

Gas, gas oil, distillate, residual

Vacuum distillation

Separation

Thermal

Separate w/o cracking

Gas oil, lube stock, residual

Atmospheric tower residual

Conversion processes—decomposition Catalytic cracking

Alteration

Catalytic

Upgrade gasoline Gas oil, coke distillate

Gasoline, petrochemical feedstock

Coking

Polymerize

Thermal

Convert vacuum residuals

Gas oil, coke distillate

Gasoline, petrochemical feedstock

Hydro-cracking

Hydrogenate

Catalytic

Convert to lighter HCs

Gas oil, cracked oil, residual

Lighter, higher-quality products

a

Hydrogen steam reforming

Decompose

Thermal/ catalytic

Produce hydrogen

Desulfurized gas, O2, steam

Hydrogen, CO, CO2

a

Decompose

Thermal

Crack large molecules

Atm tower hvy fuel/distillate

Cracked naphtha, coke, residual

Decompose

Thermal

Reduce viscosity

Atmospheric tower residual

Distillate, tar

Combining

Catalytic

Unite olefins and isoparaffins

Tower isobutane/ cracker olefin

Iso-octane (alkylate)

Grease compounding Combining

Thermal

Combine soaps and oils

Lube oil, fatty acid, alky metal

Lubricating grease

Polymerizing

Catalytic

Unite 2 or more olefins

Cracker olefins

High-octane naphtha, petrochemical stocks

High oct. Reformate/ aromatic

Steam cracking

Visbreaking

Conversion processes—unification Alkylation

Polymerize

Conversion processes—alteration or rearrangement Catalytic reforming

Alteration/ dehydration

Catalytic

Upgrade lowoctane naphtha

Coker/hydrocracker naphtha

Isomerization

Rearrange

Catalytic

Convert straight chain to branch

Butane, pentane, Isobutane/pentane/ hexane hexane (Continued)

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TABLE 3.12

(Continued)

Process name

Action

Method

Amine treating

Treatment

Deslating

Purpose

Feedstock(s)

Product(s)

Absorption Remove acidic contaminants

Sour gas, HCs w/CO2 & H2S

Acid free gases & liquid HCs

Dehydration

Absorption Remove contaminants

Crude oil

Desalted crude oil

Drying and sweetening

Treatment

Abspt/ therm

a

Solvent extr.

Absorption Upgrade mid distillate and lubes

Cycle oils & lube feedstocks

High-quality diesel & lube oil

Catalytic

Remove sulfur, contaminants

High-sulfur residual/gas oil

Desulfurized olefins

Treatment processes

Furfural extraction

Hydrodesulfurization Treatment

Remove H2O and Liq Hcs, LPG, sulfur cmpds alky feedstk

Sweet & dry hydrocarbons

Hydrotreating

Hydrogenation Catalytic

Remove impurities, saturate HCs

Residuals, cracked HCs

Cracker feed, distillate, lube

Phenol extraction

Solvent extr.

Abspt/ therm

Improve visc. index, color

Lube oil base stocks

High-quality lube oils

Solvent deasphalting

Treatment

Absorption Remove asphalt

Vac. tower residual, propane

Heavy lube oil, asphalt

Solvent dewaxing

Treatment

Cool/filter Remove wax from lube stocks

Vac. tower lube oils

Dewaxed lube basestock

Solvent extraction

Solvent extr.

Abspt/ precip.

Separate unsat. oils

Gas oil, reformate, distillate

High-octane gasoline

Sweetening

Treatment

Catalytic

Remv H2S, convert mercaptan

Untreated distillate/ gasoline

High-quality distillate/gasoline

a

Note: These processes are not depicted in the refinery process flow chart.

Bjorndalen et al. (2005) developed a novel approach to avoid flaring during petroleum operations. Petroleum products contain materials in various phases. Solids in the form of fines, liquid hydrocarbon, carbon dioxide, and hydrogen sulfide are among the many substances found in the products. According to Bjorndalen et al. (2005), by separating these components through the following steps, no-flare oil production can be established. Simply by avoiding flaring, over 30% of pollution created by petroleum operation can be reduced. Once the components for no-flaring have been fulfilled, value-added end products can be developed. For example, the solids can be used for minerals, the brine can be purified, and the low-quality gas can be reinjected into the reservoir for EOR.

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4 Fundamentals of separation of oil and gas 4.1 Introduction Petrochemical products are ubiquitous and are integral to modern societies. They include plastics, fertilizers, pharmaceuticals, packaging, clothing, digital devices, medical equipment, detergents, tires, and many others. They are also found in many parts of the modern energy system, including solar panels, wind turbine blades, batteries, thermal insulation for buildings, and electric vehicle parts. Already a major component of the global energy system, the importance of petrochemicals is continuing to grow. Demand for plastics—the most familiar group of petrochemical products—has outpaced that of all other bulk materials (such as steel, aluminum, or cement), and has doubled since 2000 (Fig. 4.1). This dominance of the oil and gas sector in our current civilization does not have to curtailed if sustainable technologies can be introduced for processing petroleum resources. The plastic era is synonymous with the current civilization. Despite negative propaganda against fossil fuel, the use of petroleum products is growing. Advanced economies, such as the United States and Europe, currently use up to 20 times as much plastic and up to 10 times as much fertilizer as developing economies such as India and Indonesia, on a per capita basis. This underscores huge potential for growth worldwide (Fig. 4.2). Overall, usage of petroleum products is synonymous with GDP growth. The growth in demand for petrochemical products means that petrochemicals are set to account for over a third of the growth in oil demand to 2030, and nearly half to 2050, ahead of trucks, aviation, and shipping. Petrochemicals are also poised to consume an additional 56 billion cubic meters of natural gas by 2030, equivalent to about half of Canada’s total gas consumption today. Simplified levelized cost of petrochemicals for selected feedstocks and regions, 2017. After two decades of stagnation and decline, the United States has returned to prominence as a low-cost region for chemical production thanks to the shale gas revolution. Today, the United States is home to around 40% of the global ethane-based petrochemical production capacity. However, the Middle East remains the low-cost champion for key petrochemicals.

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FIGURE 4.1 Growth in petrochemicals since 1971 (IEA, 2018).

Petrochemicals can be defined as a large group of chemicals derived from natural gas and petroleum and further used for a variety of chemical purposes, which are extremely important in modern civilization. However, petroleum resources are not usable in their original form and must be processed, so numerous usable products can be produced. These processes are responsible for generating a huge volume of wastewater to be discharged into the environment. Because environmental policy is increasingly severe, water contaminated with petroleum derivatives and processing additives should be treated to separate these derivatives from water before it can return to the environment. These chemicals, if of synthetic origin, are harmful to nature and can render the final process unsustainable. Sustainability can be restored by introducing natural catalysts and other chemicals. Similarly, even energy sources should be improved. In order to achieve that feat, one must understand the science behind mass-to-energy transition. The effluents are mainly produced by extraction and physical separation processes such as atmospheric and vacuum distillation, deparaffinization, and deasphalting, and also by processes involving chemical conversions by isomerization, alkylation, etherification, catalytic reform, etc. Therefore wastewater composition is qualitatively similar to petroleum oil and/or gas production.

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FIGURE 4.2 Demand for plastic resin in various countries (IEA, 2018).

The major compounds of the wastewater include (1) oil compounds; (2) dissolved formation minerals; (3) production chemical compounds; and (4) production solids (including formation solids, corrosion and scale products, bacteria, waxes, and asphaltenes). Among pollutants present in effluents from petrochemical industries at higher concentrations, oil
water emulsions stand out. Besides oil
water emulsions, specific chemical concentrations of wastewaters vary considerably with the geographical location and refining processes. Table 4.1 lists chemical compositions of typical wastewaters from petrochemical and gas production (Ji, 2015). Each of these pollutants can have value if the extraction process is correctly designed. At the same time, they can become sustainable, meaning ecologically benign. Phase equilibrium calculations for petroleum reservoir fluids may generally involve the treatment of a number of fluid and solid phases. Although oil, water, and gas separation is most commonly discussed in petroleum engineering, interactions with solid are also

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TABLE 4.1 Typical wastewater composition from petrochemical and gas production. Component

Oil wastewater (mg/L)

Gas wastewater (mg/L)

Aliphatic, C2
C5

1

1

Aliphatic, .C5

5

10

Fatty acids, C2
C5

300

150

Benzene

8

25

Naphthalenes

1.5

1.5

Phenols

5

5

HCO3 2

1538.1

5870.3

H2S

22.5

65

130,636

2389.5

4594.1

24.1

80,421.2

4169.3

398.6

35

894.1

19

4395.5

11

Sr

88.9

63

Fe21

65.3

0.65

Organic composition

Inorganic composition

2

Cl

SO42 2 1

Na 1

K

1

Mg

1

Ca

1

important. Petroleum resources account for • • • •

petrochemicals; fuel from refinery or crude chemicals that undergo semicontinuous processing; specialty chemicals that undergo batch processing like paints, coatings, and dyes; and chemicals for pharmaceutical industries.

Typical calculations of equilibrium conditions can be classified in two categories. In the first category, the composition and properties of the coexisting phases at a given set of temperature and pressure are required. In the second case, the saturation condition, either temperature or pressure is searched for a given composition and pressure, or temperature. In this chapter, the fundamental science behind the surface phenomena is discussed, both from conventional and new perspectives.

4.2 Fundamental of surface chemistry Somorjai (2002) describes the historical background of surface chemistry. Surface chemistry, like other branches of physical chemistry, was historically developed

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through macrosopic studies. These included measurements of adsorption 2 desorption equilibria (adsorption isotherms), spreading of monomolecular films, surface dissociation of diatomic molecules, and kinetic studies of desorption, sticking, and catalytic oxidation of CO and H2. Models of surface structures were proposed by Langmuir and Taylor on the bases of experimental findings. Molecular-level studies of surface chemistry were delayed as compared to other fields of physical chemistry until the late 1950s as instrumentation to detect properties of the very small number of surface atoms (1015 cm22) in the presence of a large number of bulk atoms (1022 cm23) were not available. At present we have over 65 techniques (photon, electron, molecule, ion scattering, and scanning probes) that can investigate composition, atomic and electronic structures, and the dynamics of their motion with # 1% of a monolayer sensitivity. Key results include quantitative determinations of surface segregation of constituents that minimize surface free energy, discovery of clean surface reconstruction and adsorbate induced restructuring, and the uniquely high chemical activity of rough surfaces and defects (steps and kinks). In situ molecular studies during surface reaction reveal the need for restructuring of metal surface atoms by a highly mobile strongly adsorbed overlayer to maintain catalytic activity: additives that inhibit mobility on the surface poison chemical reactivity. New techniques permitting molecular surface studies at high pressures and at solid 2 liquid interfaces greatly accelerated the developments of molecular surface chemistry and permitted in situ studies of complex surface chemical phenomena: catalytic reactions, electrode surface chemistry, and polymer surfaces. As always, further developments in techniques control the rate of progress of molecular surface chemistry.

4.2.1 Haber process The field of surface chemistry started with heterogeneous catalysis pioneered by Paul Sabatier on hydrogenation and Fritz Haber on the Haber process. Irving Langmuir was also one of the founders of this field, and the scientific journal on surface science, Langmuir, bears his name. The Langmuir adsorption equation is used to model monolayer adsorption where all surface adsorption sites have the same affinity for the adsorbing species and do not interact with each other. Let us review these two processes. The Haber process is one of the most popular ways to produce NH3. This process, invented in the early 20th century, marked the beginning of plastic culture that would see replacement of natural processes with artificial ones (Islam and Khan, 2019). This process involves synthesis of ammonia in order to produce the first line of chemical fertilizers that have become common ever since. This surge in chemical fertilizer is synonymous with “green revolution,” which caused devastation to conventional agricultural practices and sustainability (Fig. 4.3). In 1930, world farmers applied 1.3 million metric tons (Tg) of N in fertilizers, and after World War II, they still were applying only 3
4 Tg. This break-neck pace of about 10% increase a year was moderated during 1960s—a time when “green revolution” was orchestrated around the developing countries. However, the growth continued. During the 1973 oil shock, usage of oil fell for the first time. It was due to shortage of petroleum raw material

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FIGURE 4.3 The world rise in millions of metric tons (Tg) of N in fertilizer, and plotted above each year, the annual percentage change in the world and the United States calculated from 4 years before until 5 years later. Sources: Website 1, USDA, 1997; Website 2.

that is needed to produce synthetic fertilizers. However, that decline was short-lived and a rapid pace of growth got picked up. It climbed again, only to pause in 1981 ($35.bbl) and 1985 ($26/bbl) before reaching a maximum near 80 Tg in 1988 ($15/bbl), a level one can safely call at least 100-fold more than in 1900. There is a correlation between cheap oil and fertilizer usage. After the peak of 1988, fertilizer usage declined. Although the world use decline after 1988 was aggravated by falls in Central Europe, the former USSR, and Western Europe, the introduction of GMO in crop that had boosted crop production may have played a role as well. Although world consumption began to recover in 1993, it scarcely reached its 1988 maximum by 1995. The annual rate of change slowed from faster than 10% in the 1960s until it stagnated after 1988 (Fig. 4.4). Fig. 4.5 shows the trend continues beyond 2000 and the only two anomalies (in 2005 and 2008) are related to extraordinary increases in oil/gas prices. Note that after 2005
06 and 2007
08 were the years when the so-called “gas war” was prominent in Europe due to Russia’s insistence on higher gas prices. Natural gas is the raw material used for producing chemical fertilizers. Several additional points arise from comparison of the rate of change in the United States with the world use (including the United States). Fig. 4.4 indicates that because the US adopted fertilizer early and rapidly, its rate of change slowed about a decade sooner. Also, the slowing rate of change and even decline in the United States confirm that use can stagnate without the crises in the old Soviet Union. In the United States, the federal program that shrank harvested cropland about one-sixth in 1983 caused a notable dip. Another feature, a peak in 1994, followed Midwestern floods. After the US capacity to manufacture N fertilizers more than doubled from 1964 to 1981, plant closures and little construction lowered capacity 15% by 1995. Specific causes of specific dips and peaks can be named for both the world and the United States. The general cause of the inexorable slowing, however, is the inevitable limit of the need for more new technology. The Original Haber process involves fixation of atmospheric nitrogen in the form of ammonia, which in turn allows for the industrial synthesis of nitrogen fertilizers.

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FIGURE 4.4 The world rise in millions of metric tons (Tg) of N in fertilizer, and plotted above each year, the annual percentage change in the world and United States calculated from 4 years before until 5 years later. Source: From Islam and Khan (2019).

The process needs a temperature of 400 C and a pressure of about 150 bar to perform the reaction properly. The reaction generates heat in the process, which can be utilized if the process is properly integrated. The reversible reaction is as follows (Darmawan et al., 2022):























! NH3 1 46:1 kJ=mol H2 1 N2
Heat; pressure

(4.1)

The basic process flow of the Haber process is shown in Fig. 4.6. N2 and H2 generated during the SCL process are among the input streams. With stream recycling to provide heat integration for the prior processes, the conversion ratio is assumed to be 30% per cycle. Recycled gas and purge gas are supplied from the unreacted gas that still contains H2 and N2. The former is used to purge the reactor, while the latter is recirculated into the NH3 processing reactor. The purge gas is used for combustion after the purging process, primarily for heat and power generation. Ninety percent of the unreacted gas is used as a purge gas in this system. This amount is required so that enough heat can be produced to support processes, which uses a lot of water. The reaction is reversible and exothermic, so that a high yield of ammonia is favored by low temperature. It is due to Chatelier’s principle. Le Chaˆtelier’s principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to re-establish an equilibrium. It follows that both chemical and physical equilibrium is governed by this principle. The temperature, pressure, and concentration of the system are all factors that affect equilibrium. From Eq. (4.1), it can be seen that the reaction is exothermic with a high pressure and low temperature favoring ammonia synthesis at equilibrium conditions. Although the theoretical

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FIGURE 4.5 World fertilizer use, projected until 2030 (FAO, 2015). Source: From FAO, 2015. World Agriculture: Towards 2015/2030. An FAO Perspective. Food and Agriculture Organisation.

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FIGURE 4.6 Basic flow diagram of the Haber
Bosch process.

ammonia equilibrium concentration can be close to 100% at low temperatures and high pressures, the ammonia formation rate is extremely slow and not suitable for production purposes. Due to this the Haber
Bosch process is conducted at high temperature and pressure. However, at these conditions the equilibrium shifts so as to decompose the produced ammonia and give a lower production rate However, the rate of reaction would be too slow for equilibrium to be reached at normal temperatures, so an optimum temperature of about 450 C is used. This process was industrialized by Carl Bosch, with the first ammonia synthesis plant being built in 1911. Due to this the process of producing ammonia from H2 and N2 at high temperature and pressure is known as the Haber
Bosch process. Fritz Haber and Carl Bosch won the Nobel Prize in Chemistry in 1918 and 1931, respectively for their work on this process. In 2007, Gerhard Ertl won the Nobel Prize in Chemistry for his contribution to the surface chemistry of iron catalysts. As such, the process is intrinsically linked to surface chemistry. Fused-iron catalysts are by far the most studied and widely applied of all the ammonia synthesis catalysts. Fused-iron catalysts are derived from three possible iron oxides (Darmawan et al., 2022): • Fe2O3(hematite). • Fe3O4(magnetite). • Fe1-xO (wu¨stite). All these are manufactured. However, in nature similar ores exist. For instance, magnetite (Fe3O4, 72.4% Fe), hematite (Fe2O3, 69.9% Fe), goethite (FeO(OH), 62.9% Fe), limonite (FeO(OH) n(H2O), 55% Fe), or siderite (FeCO3, 48.2% Fe). Wu¨stite, on the other hand, is formed as an oxide layer on iron oxidized at temperatures above 570 degrees should also become unstable on cooling to room temperature. Physical properties of wu¨stite, including cation diffusion, electrical conductivity, and magnetic properties, are dependent on defect structure type and exsolution, as well as degree of nonstoichiometry. Catalysts are rendered unstable in order to increase reactivity. However, this process also makes the final



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product unsustainable (Khan and Islam, 2016). Of these, catalysts derived from Fe3O4 are the most commonly used in industrial ammonia synthesis. The first ammonia synthesis catalysts were based on magnetite with the commonly held belief that its molecular structure provided the best activity for ammonia synthesis. Therefore the majority of catalyst development over the last century was devoted to the promoters of the magnetite catalysts. Over the subsequent years, the focus has been to describe the molecular structure with quantum theories. Islam and Khan discussed an alternate depiction of molecular and subatomic structures. Today most ammonia synthesis plants use fused-iron catalysts that use a variety of carefully designed promoter materials, such as potassium and aluminum oxide. The higher the pressure the greater the yield, although there are technical difficulties in using very high pressures. A pressure of about 250 atmospheres is commonly employed. Catalysts play a pivotal role in determining the ultimate sustainability of a process. The new emerging ammonia synthesis catalysts, including electride, hydride, amide, perovskite oxide hydride/ oxynitride hydride, nitride, and oxide promoted metals such as Fe, Co, and Ni, are considered to be “green” alternatives to the conventional fused-Fe and promoted-Ru catalysts for existing ammonia synthesis plants (Humphreys et al., 2021). In the conventional Haber
Bosch process, fossil fuels such as natural gas and coal are normally used as the energy sources for ammonia synthesis. This process is considered to be unsustainable because it releases millions of tonnes of CO2 into the atmosphere, which is about 1%
2% of the global CO2 emission (Islam and Khan, 2019). It is believed that “green” ammonia production would amount to changing the energy sources from fossil fuel to “renewable” energy technologies that use Hydrogen production with electrolyzers, powered through “renewable” energy. For instance, Smith et al. (2022) report that an ammonia loop fed with H2 from an electrolyzer would produce 0.38
0.53 tonnes of CO2 per tonne of NH3 compared to 1.673 tonnes of CO2 per tonne of NH3 for the loop with H2 from methane reforming. The electrolyzer loop would also improve energy efficiency by 50%. In their calculations, Smith et al. (2022) used an electrolyzer efficiency of 60% in line with those currently available. The catalytic synthesis of ammonia relies on the surface reaction of nitrogen and hydrogen on the catalyst surface. This surface reaction is achieved through the chemisorptions of the reactants on to the catalyst surface. This differs from the other adsorption process of physisorption (discussed in the follow-up section) due to the formation of a chemical bond with surface and reactants. When it comes to sustainability, few have considered the role of catalysts in determining long-term sustainability (Khan and Islam, 2016). However, they point out that materials used in catalysts play a pivotal role. Smith et al. (2020) proposed reaction mechanisms for the catalyzed reaction of nitrogen and hydrogen to form ammonia are as follows: N2 1  2N2 

(4.2)

N2  1  22N

(4.3)

H 1 N 2NH 1 

(4.4)

NH 1 H 2NH2  1 

(4.5)

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NH2 1 H 2NH3 1 

(4.6)

NH3 2NH3 1 

(4.7)

H2 1 2 22H

(4.8)

From this model there are three proposed rate-limiting steps, which are 1. The dissociative adsorption of dinitrogen. 2. The reaction on the catalyst surface of adsorbed species. Numerous studies indicate that the step 3 is the most limiting. Smith et al. (2022) reviewed advances in this technology, as depicted in Fig. 4.7. These catalysts can be used for both conventional centralized large-scale Haber
Bosch ammonia synthesis plants and distributed small-scale “green” ammonia production via the same process. Smith et al. (2022) proposed to replace the CO2 intensive methane-fed process with hydrogen produced by water splitting using “renewable” electricity. The underlying assumptions are as follows: • Hydrogen produced through methane-fed process is worse or less sustainable than more energy-intensive water splitting process. • Electricity from fossil fuel is less sustainable than electricity from “renewable.” In Chapter 3, this notion is refuted. It is recognized that increased energy efficiency and the development of small-scale, distributed, and agile processes that can align with the geographically isolated and intermittent energy sources are the key developing sustainable technologies. The former requires not only higher electrolyzer efficiencies for hydrogen production but also a holistic approach to the ammonia synthesis loop with the replacement of the condensation separation step by alternative technologies such as absorption and catalysis development. Such innovations will open the door to moderate pressure systems, the development and deployment of novel ammonia synthesis catalysts, and even more importantly, the opportunity for integration of reaction and separation steps to overcome equilibrium limitations. In the proposed scheme, hydrogen is produced by primary and secondary steam methane reforming reactors (SMR), followed by a two-stage water
gas shift reactor, CO2 removal, and methanation. The first SMR reactor operates in allothermal conditions at around 850 C
900 C and 25
35 bar and the energy required for the endothermic reaction is provided by external combustion of methane fuel through furnace tubes that run through the catalyst bed. The second SMR reactor is autothermal, air is compressed and fed to the reactor to provide heat of reaction by partial oxidation of the reagents at 900 C
1000 C. The addition of air also provides the stoichiometric nitrogen required for the downstream Haber
Bosch reaction. The SMR process exports steam to be used elsewhere, mostly for compression energy. The SMR outlet mixture of carbon monoxide, hydrogen, and unreacted steam and methane is introduced into the two-stage water
gas shift (WGS) reactor to maximize CO conversion to hydrogen. The WGS reaction is exothermic and heat must be removed to minimize CO concentration at equilibrium. Then, CO2 is

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FIGURE 4.7 Graphical overview of strategies to improve Haber
Bosch ammonia synthesis (Humphreys et al., 2021).

removed through the Benfield or Selexol process and finally, a methanation reactor converts any remaining carbon monoxide back into methane to minimize the poisoning of the Haber
Bosch catalyst. Argon and methane present accumulate as inerts in the downstream synthesis loop (Fig. 4.8). Although the steam methane reforming reactions are endothermic, the high reaction temperature and the need to cool substantially for the water gas shift reaction means that there is substantial waste heat available. This heat is used for raising high-pressure steam,

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(A) Methane-Fed System H2O

WGS Reactor

N2 H2 CO CO2

(B) Electrically Driven System CO2 CO2 removal

Methanaon

N2, H2 CO

O2

H2O

Electrolyser

H2 Producon

H2O N2, H2 CO

Sream System

Air

N2 H2

CO2

Electricity

Steam Reforming Reactors

Furnace Steam Export

H2, N2 CH4, Ar

CH4

Waste Heat HB Reactor

HB NH3

Air

PSA

Purge

NH3 H2, N2

Condenser NH3

Refrigeraon Compressor

H2, N2

Purge

Recycle Compressor

Condenser H2O

Mul-stage Feed Compressor

NH3

Refrigeraon Compressor

H2, N2

HB Reactor

NH3 H2, N2 H2O

Mul-stage Feed Compressor

Recycle Compressor

FIGURE 4.8 Schematic diagram of (A) a typical conventional methane-fed Haber
Bosch process and (B) an electrically powered alternative. Hydrogen and ammonia production stages are separated for illustration purposes to identify similitudes and differences between both technologies (Smith et al., 2020).

which is expanded in steam turbines for compression, mainly used for compression of the feed in the Haber
Bosch loop and the reformer combustion air compressor which are the largest two energy users. The use of methane as feedstock inevitably leads to significant CO2 emissions from the process and this is further compounded by the use of methane as fuel for the primary reformer furnace.

4.2.2 Langmuir adsorption American scientist, Irving Langmuir (1881
1957) was awarded the 1932 Nobel Prize for Chemistry for his discoveries and investigations in surface chemistry. His most important contribution led to many branches in physical chemistry. His discoveries were based on macroscopic studies, involving adsorption 2 desorption equilibria and the heats of adsorption and the spreading of monomolecular films of organic molecules on water (Somorjai, 2002). His studies of bonding identified the surface dissociation of diatomic molecules (H2, O2, and N2) mostly on tungsten. The original context was illumination with tungsten. Soon after his PhD in 1906, he engaged in conducting experiments with bendable tungsten wire, originally developed by his colleague William Coolidge. Langmuir’s goal was to find a way to keep tungsten lamps from “blackening,” or growing dim as the inside of the bulb became coated with evaporated tungsten. The eventual finding that nitrogen slows down evaporation of tungsten from the radiating filament needed the so-called adsorption studies that Langmuir is most famous about. He also discovered that thin filaments radiate heat faster than thick filaments, and coiled tungsten wire radiates heat as if it were a solid rod. He suggested filling the bulbs with nitrogen (and later, argon) gas, and twisting the filament into a spiral form to inhibit the vaporization of tungsten. Overall, his lamps gave 12
20 lm/W (depending on the wattage), while Coolidge’s vacuum lamps gave about 10 lm/W.

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Langmuir’s kinetic studies included CO and H2 oxidation catalyzed by platinum, the desorption rates of H, O, and N from W and Mo, and the sticking probability of H2. Langmuir is best known is his work in surface chemistry, as well as his elaboration on the theory of chemical bonding in terms of electrons, first expressed by Gilbert Lewis (Website 3). In Lewis’ model electrons form stable groups of eight at the corners of a cube. Langmuir proposed that these octets could be filled by sharing pairs between two atoms: the “covalent” bond. For example, for the H2 molecule, which contains a purely covalent bond, the scenario depicted in Fig. 4.9 occurs. Each hydrogen atom in H2 contains one electron and one proton, with the electron attracted to the proton by electrostatic forces. The electrons in the two atoms repel each other because they have the same charge (E . 0). Similarly, the protons in adjacent atoms repel each other (E . 0). The electron in one atom is attracted to the oppositely charged proton in the other atom and vice versa (E , 0). A plot of the potential energy of the system as a function of the internuclear distance is shown in Fig. 4.10. It shows that the system becomes more stable (the energy of the system decreases) as two hydrogen atoms move toward each other from r 5 N, until the energy reaches a minimum at r 5 r0 (the observed internuclear distance in H2 is 74 pm). Thus at intermediate distances, proton
electron attractive interactions dominate, but as the distance becomes very short, electron
electron and proton
proton repulsive interactions cause the energy of the system to increase rapidly. The valence electron configurations of the constituent atoms of a covalent compound are important factors in determining its structure, stoichiometry, and properties. For example, chlorine, with seven valence electrons, is one electron short of an octet. If two chlorine atoms share their unpaired electrons by making a covalent bond and forming Cl2, they can each complete their valence shell:

Each chlorine atom now has an octet. The electron pair being shared by the atoms is called a bonding pair; the other three pairs of electrons on each chlorine atom are called lone pairs. Lone pairs are not involved in covalent bonding. If both electrons in a covalent bond come from the same atom, the bond is called a coordinate covalent bond. FIGURE

4.9 Attractive and repulsive interactions between electrons and nuclei in the hydrogen molecule.

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FIGURE 4.10 A plot of potential energy versus internuclear distance for the interaction between two gaseous hydrogen atoms.

One can illustrate the formation of a water molecule from two hydrogen atoms and an oxygen atom using Lewis dot symbols:

The structure on the right is the Lewis electron structure, or Lewis structure, for H2O. With two bonding pairs and two lone pairs, the oxygen atom has now completed its octet. Moreover, by sharing a bonding pair with oxygen, each hydrogen atom now has a full valence shell of two electrons. Langmuir’s most notable contribution in surface chemistry was in developing the concept of adsorption, in which every molecule striking a surface remains in contact with it before evaporating, thus forming a firmly held monolayer. The assumption of monolayer is simplistic. It involves the following assumptions: • • • •

Adsorbing surface is immobile. All sites are energetically equivalent and the energy of adsorption is equal for all sites. Each site can hold at most one molecule of A (monolayer coverage only). There is no interaction between adsorbate molecules on adjacent sites.

Even with these unrealistic and highly homogenized features, the monolayer model has enjoyed widespread applications in practically all fields of surface phenomena (Malila and Prisle, 2018).

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Langmuir discovered hydrogen in its atomic form, which led to the development of an atomic hydrogen welding torch that produced a flame of such high temperature that it is still used for welding metals, which are not affected by the standard oxyacetylene. His studies also offered the first clear picture of thermionic emission: the flow of charged particles from hot metals. Thermionic emission (archaically known as the Edison effect) is the flow of charged particles called thermions from a charged metal or a charged metal oxide surface, caused by thermal vibrational energy overcoming the electrostatic forces holding electrons to the surface. Langmuir was among the first to work with plasmas, and actually coined the term to describe the aggregations of ionized gas with unusual electric and magnetic properties. Currently, thermionic emission is handled with quantum theory. We would see in the later section, such theory is not necessary with the comprehensive model. In the previous section, it is identified as the Avalanche model, in this chapter is expanded to the so-called galaxy model. With the current convention, at room temperature, few of the quantum states above the Fermi level will be filled. The highest energy level that an electron can occupy at the absolute zero temperature is known as the Fermi Level. The Fermi level lies between the valence band and conduction band because at absolute zero temperature the electrons are all in the lowest energy state. Fermi level is a term used to describe the collection of electron energy levels at absolute zero temperature. It is a concept of Fermi
Dirac statistics. The Fermi level refers to the total of kinetic energy and potential energy of a thermodynamic system containing fermions. Therefore the Fermi level can also be named as the electrochemical potential of a Fermion. The Fermi level can be defined even for fermions that are in complex interacting systems when the thermodynamic equilibrium state of that system is considered. Fermi energy is the energy difference between the highest and lowest occupied singleparticle states in a quantum system of noninteracting fermions at absolute zero temperature. The single-particle state of a quantum system refers to the state of a single particle being isolated. Fermions are particles that follow Fermi
Dirac statistics. Fermions mainly include quarks and leptons along with electrons, protons, and neutrons. Absolute zero temperature is the lower limit of a thermodynamic temperature scale. A Fermi gas is a group of fermion particles having no interactions between those fermions. Once again, this is an absurd premise that defies continuity of mass and energy. It is later shown that such assumptions are not necessary. The lowest occupied state of a Fermi gas is known to have a zero kinetic energy. But the lowest occupied state of a metal is the bottom of its conduction band (the bands closest to the Fermi levels, thus determining the electrical conductivity of the metal) (Fig. 4.11). The fermions obey the Pauli Exclusion Principle (A principle that states two identical fermions cannot occupy the same quantum state). Therefore the Fermi gases can be analyzed in its single-particle state. There are different single-particle states having different energies. The ground state of the whole system can be found by adding one particle into the system at a time. These added fermions will then occupy the lowest unoccupied states of that system. The Fermi energy can be determined when all the unoccupied states have been occupied by fermions. This means, even if all the energy is extracted from a Fermi gas, the fermions will still be in movement at high speeds (Huffman, 2003). However, as can be seen from the Fermi factor expression, there will always be some electrons occupying the high-energy states as long as T . 0. Due to their random motion inside the metal, many electrons will impinge on the surface. Those electrons with kinetic energies

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FIGURE 4.11

overlap

A comparison of the band gaps.

increasing energy

conduction band

Fermi energy

band gap valence band

metal

semiconductor

insulator

greater than the work function barrier may escape the metal. Those that cross the boundary at the surface will transform part of their kinetic energy (i.e., φ eV) into potential energy. It can be shown, either from thermodynamic considerations or from the application of statistical mechanics in connection with the quantum mechanics of electrons in metals, that the current density J of electrons emitted from a uniform surface of a pure metal of absolute temperature T can be expressed by the Richardson equation,   (4.9) J 5 ð1 2 rÞAT 2 exp 2φ=kT where A is a constant and r is the electron reflection coefficient of the surface (of the order of 0.05). The coefficient A is composed of a combination of fundamental physical constants. A 2 4πmk2 e=h3 5 120A=cm2 K2

(4.10)

where e is the electronic charge, m is the electronic mass, and h is Planck’s constant. If the reflection coefficient is assumed to be zero, it is convenient to express the Richardson equation as follows:   J 5 120 T 2 exp 211606φ=T (4.11) where J is the current density in amperes per (centimeter)2, φ is the work function in electronvolts, and T is the electrode temperature in kelvins. The value J is called the saturation current density and corresponds to a zero electric field (horizontal potential distribution). A strong applied electric field changes the electron emission, because its effects are superimposed on those of the image force, and alters the shape of the potential distribution outside the electrode.

4.2.3 Connection between subatomic and bulk properties One of the biggest problems in describing material properties is the fact that the theories are based on atomic theory whereas validated with bulk properties, while bulk properties are observable and measurable, atomic and subatomic properties are not (Khan and Islam, 2016). In fact, it is clear today that at no space solid, rigid, uniform, and spherical particles that was once thought to be atom do not exist. Instead, subatomic particles are more akin to clouds—a phenomenon that has been described by Islam with his

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“galaxy model” (Islam, 2014). This galaxy model is capable of explaining both nano- and bulk-scale properties. It is important to have a correct description of fundamental building “blocks” because if they are described improperly, the description of the macrosystem will be meaningless irrespective of what parameters are introduced in order to match bulk properties with governing equations. Take, for instance, an example of an atom. If this atom is considered to be a collection of single nucleus and electrons, with nucleus being a collection of rigid particles and electrons are much smaller rigid particles, there is no room left to consider some 69 smaller particles that we know exist. This description is not any improvement over the original atomic theory that considered the entire atom to be a solid spherical particle. However, New Science takes the pragmatic approach and forces analytical solutions based on hydrogen atoms. It is assumed that one electron orbits around one proton with the following properties remaining constant: 1. Size of the proton (comes from the assumption that it is a rigid, uniform sphere). 2. Uniform spinning rate and angle. 3. Uniform orbital path. The above assumptions collapse, of course, as soon as there is more than one electron, in which case nuclear-electron force has to be adjusted for accommodating electron
electron forces. This complexity is addressed by invoking approximations, because of the presence of a nonlinear terms make it impossible to determine an analytical solution. In order to justify such assumptions, the notion of atomic orbital (AO), with an associated discrete energy level is introduced. No justification for such discrete nature of energy level is given. In addition, various angular moments are ascribed, once again without justification. Different types of orbital shapes are introduced, such as spherical (s-orbital), club-like (p-orbital) or a more complicated (d-, f -orbitals) shape. The eight valence electrons of a neon atom, for example, occupy one s- and three p-orbitals around the nucleus, one spin up and one spin down per orbit (Karplus and Porter, 1970), where the energy level of the s-orbital is lower than that of the p-orbitals. The reason there is no explanation is provided is that quantum mechanics is invoked. The rules of quantum mechanics dictate that the energy levels are discrete. In layman’s terms, this illogical assertion means there is this dogma that A can be A and B at the same time. As pointed out by Islam et al. (2015, 2016) and Khan and Islam (2016), this is simply the polished and disguised version of Dogma. The next level of dogma “science” moves to a bigger structure, that is the molecule that obtained from the combination of several atoms. It is thus asserted that electrons orbit collectively around more than one nucleus. In a molecule, electrons that are responsible for the covalent bonds between individual atoms can no longer be ascribed to one individual atom, but they are “shared.” For instance, in methane (CH4), each of the four sp3 atomic orbitals of the central carbon atom is linearly combined with the s orbital of a hydrogen atom to form a bonding (σ) and an antibonding (σ*) orbital, respectively. Since these orbitals are “shared” between the atoms, they are called molecular orbitals (MO, see Fig. 4.12). The straw man argument that the lowest energy (bonding) orbitals are occupied, therefore the stability of methane is assured is made (Karplus and Porter, 1970). Based on this aphenomenal model, which is a refined version of the original Atomic theory, is then used to derive the electronic structure of more complex systems such as large molecules or atomic

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Energy σ.

p sp3

s

atom

Conduction band quantum dot

Energy gap

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FIGURE 4.12 Electronic energy levels depending on the number of bound atoms. By binding more and more atoms together, the discrete energy levels of the atomic orbitals merge into energy bands (here shown for a semiconducting material). Therefore semiconducting nanocrystals (quantum dots) can be regarded as a hybrid between small molecules and bulk material.

valence band

σ

molecule

Bulk solid-state body

Number of connected atoms

clusters. While combining atoms to form a molecule, discrete energy levels of the atomic orbitals are added to obtain similarly discrete levels of molecular orbitals (Atkins, 1986). When the size of a polyatomic system becomes progressively larger, the calculation of its electronic structure in terms of combinations of atomic orbitals becomes unfeasible and another level of absurdity is introduced. Simplifications arise if the system under study is deemed to be periodic, thus reaching the level of an infinite series. This assumption is invoked for, for instance, crystals. In this model, perfect translational symmetry of the crystal structure is assumed, and contributions from the surface of the crystal are neglected by assuming an infinite solid (periodic boundary conditions). Electrons are described as a superposition of plane waves extended throughout the solid. With these fantastically unnatural traits, the new model emerges as being able to eliminate the assumption of discrete energy and the description of Fig. 4.12 emerges. In reality, this model is not any less absurd than the original discrete model, albeit with the newly added complexity giving it a cosmetic of a real model that captures reality. Of course, the assumption of “infinity” does not apply to smaller crystals of nanometer dimensions (called nanocrystals). Therefore for nanocrystals, a new set of absurd definitions needed to be introduced. The following assumptions are added: 1. Energy levels of a nanocrystal are discrete. 2. Their density is much larger than similar atomic clusters. 3. Their spacing is smaller than for the corresponding levels of one atom or a small atomic cluster. These logical absurdities are called quantum dots. These dots mark the connection between bulk and nanoscale properties. Highest occupied atomic levels of the atomic (or ionic) species interact with each other to form the valence band of the nanocrystal. Similarly, lowest unoccupied levels combine to form the conduction band of the nanocrystal. The energy gap between the valence and conduction bands results in the band gap of the nanocrystal. As an example, consider a metallic quantum dot. Its level spacing at the Fermi level is roughly proportional to EF 5 N, where N is the number of electrons in the

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quantum dot. In very small crystals of nanometer dimensions, so-called nanocrystals, the assumptions of translational symmetry and infinite size of the crystal are no longer valid, and thus these systems cannot be described with the same model used for a bulk solid. We can imagine indeed that the electronic structure of a nanocrystal should be something intermediate between the discrete levels of an atomic system and the band structure of a bulk solid. This can be evidenced from Fig. 4.12, the energy levels of a nanocrystal are discrete, their density is much larger, and their spacing is smaller than for the corresponding levels of one atom or a small atomic cluster. Because of their discrete energy levels, such structures are called also quantum dots. The concept of energy bands and band gap can still be used. Highest occupied atomic levels of the atomic (or ionic) species interact with each other to form the valence band of the nanocrystal. Similarly, lowest unoccupied levels combine to form the conduction band of the nanocrystal. The energy gap between the valence and conduction bands results in the band gap of the nanocrystal. As an example, consider a metallic quantum dot. Its level spacing at the Fermi level is roughly proportional to EF 5 N, where N is the number of electrons in the quantum dot. Given that EF is a few eV and that N is close to 1 per atom, the band gap of a metallic quantum dot becomes observable only at very low temperatures. Conversely, in the case of semiconductor quantum dots, the band gap is larger and its effects can be observed at room temperature. The size-tunable fluorescence emission of CdSe quantum dots in the visible region of the spectrum is for instance a very explanatory illustration of the presence of a size-dependent band gap. At the outset, there is no harm in characterizing material in this fashion other than the fact that it is not logical. However, the real harm is in disconnecting metal components from the rest of the environment. In addition, such characterization of both mass and energy disconnects the mass from the energy component and makes no distinction between natural chemical and artificial ones. Crystals in nature, however, are processed very differently from the artificial processing that we are used to. Before this atomic model is confidently extended to a bulk system, three-dimensional scaling is performed and to do so the concept of “free” electron is introduced. A “free” electron means that it is delocalized and thus not bound to individual atoms. In scientific term, it means electrons are assigned the ability to exist in multiple positions in space simultaneously. It does not stop there; furthermore, assumptions are invoked. For instance, it is assumed that the interactions between the electrons, as well as the interactions between the electrons and the crystal potential, can be neglected. This amounts to neglecting mass of a snowflake while calculating the impact of an avalanche or nature (natural or artificial) of a photon while determining the role of light in an organic system. Yet, this model system, called “free-electron gas” has become foundation of the study of material properties (Ashcroft and Mermin, 1976). Unsurprisingly, scientists then marvel at how well this model captures many physical aspects of a real system, which is expected because all measuring tools are also based on the same principle (Islam and Khan, 2019). It means scientists are busy falsely measuring properties of real materials to justify theories that are based on false premises. Even then, whenever divergence occurs between measured and theoretic observations, it is explained away based on another set of false assumptions. When it becomes unbearable to maintain such theories, new parameters and yet another set of dogmatic assertions are invoked. In this particular application, it is deemed sufficient to replace the free-electron mass m by an

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“effective” mass m*, which implicitly contains the corrections for the interactions, although the “correction” remains entirely arbitrary and the original “free-electron” picture becomes the new norm. With this premise, velocity of electron, its mass, and energy are connected through the following equation:  1 1  υ 2 5 m υ2x 1 υ2y 1 υ2z (4.12) E 5 m~ 2 2 where velocity v is considered to be strictly orthogonal with components vx, vy, and vz in three dimensions. According to Pauli’s exclusion principle, each electron must be in a unique quantum state. This stunning principle assigns unique properties to otherwise homogenous, spherical, rigid, particles—called electron, without explaining why such uniform bodies will have unique properties. It is also asserted that electrons can have two spin orientations (Ms 5 1/2 and Ms 5 21/2). It then follows that two electrons with opposite spins can have the same velocity, v. This case is analogous to the old Bohr model of atoms, in which each orbital can be occupied by two electrons at maximum. In essence, the new description is nothing different from the long-discredited atomic model. In connecting the transition between energy and mass, solid-state physics introduces another layer of obscurity. The velocity term, v is replaced by wave vector, k (expressed as kx, ky, and kz) in order to describe a particle’s state. Its absolute value is called the wave number (akin to speed). The wavevector is stated to be directly proportional to the linear momentum, p and thus also to the velocity, v of the electron: ~ p 5 m~ υ5

h~ k 2π

(4.13)

In the above equation, which asserts a linear relationship between p and k obscure any role of real radiation by invoking the scaling constant, h, the Planck constant. In essence, Planck’s constant relates the energy in one “quantum” of electromagnetic radiation to the frequency of that radiation. In the International System of units (SI), the constant is equal to approximately 6.626176 3 10234 J s. All of a sudden, the entire transition from mass to energy is fabricated as this “quantum” subsequently called photon or any other unit of energy, typically characterized as devoid of mass, yet having a definite pattern in electromagnetic wave. This absurd notion forms the basis of today’s quantum Physics. The science is further obscured by the introduction of the De Broglie relation (Ashcroft and Mermin, 1976) that relates wavelength to Planck’s constant through the following relationship:   2π   (4.14) 6 k 5 ~ k 5 6 λ In this equation, wave number is related to wave length, Λ. This assumption (known as matter-wave duality) implies that matter behaves like waves, the latter being a feature of energy that has no mass attached to it. In essence, it disconnects mass from energy, implying that energy can emerge from nothing. After all, this molestation of mass energy transition comes to the manipulation of the boundary condition. It is assumed that periodic boundary conditions exist for every particle. This is the opaque version of the real

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boundary condition that is being imposed, the real meaning the infinite boundary condition that was the one that gave analytical solutions in the past. The scientific meaning of imposition of such an absurd boundary condition is to assert that an electron does not “feel” the border, therefore it “behaves” as though it is in a bulk. Now that this depiction of bulk material has nothing to do with reality, scientists solve the resulting equations with a great deal of zeal and draw a 3D picture of electrons and resulting energy (Fig. 4.13). The debate now becomes that of cosmetics of this visualization and how to make the predictions close to real observations—observations that are made with the tools that have the same depiction imbedded in it. In this figure, part (A) shows how a solid entity can be modeled as an infinite crystal along all three dimensions x, y, and z. Part (B) shows how periodic boundary conditions yield standing waves solutions for free electrons. Each of the dots shown in the figure represents a possible electronic state kx, ky, and kz. Each state in k-space can be only occupied by two electrons. Part (C), the dispersion relation for free electrons in a threedimensional solid is shown. The energy of free electrons varies with the square of the wavenumber, and its dependence on k is described by a parabola. For a bulk solid, the allowed states are quasicontinuously distributed and the distance between two adjacent states (here shown as points) in k-space is very small. In part (D), density of states of D3d for free electrons in a three-dimensional system is shown. The allowed energies are quasicontinuous and their density varies with the square root of the energy E1/2.

FIGURE 4.13

Electrons in a three-dimensional bulk solid. Source: From Ashcroft and Mermin (1976).

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FIGURE 4.14 Size dependence of the energy gap for colloidal CdSe quantum dots with diameter d. Source: From Trindade et al. (2001).

Fig. 4.14 shows how the theoretical curve based on the above formulation ends up predicting experimental values within the margin of error. As stated earlier, the entire exercise of developing equations that have nothing to do with the actual material properties and everything to do with formulating an equation that will yield desired results have indeed borne fruit.

4.2.4 The correct formulation The term nanoparticle describes a subset of the colloidal range between 1 and 100 nm (Hochella, 2002). The distinction is justified partly on their very high specific surface area (Lead and Wilkinson, 2007) and partly on their potentially different behavior at this small scale, due to the spatial constraint of electronic properties. As particles transition to smaller and smaller sizes, they become effectively all surface with minimal internal volume, giving rise to their enhanced reactivity. Fig. 4.15 includes results from Islam and Mokhatab (2018) that corrects the conventional graph to account for the continuity in subatomic level. This figure shows the difficulties in both describing phenomena and handling of such materials. Engineered materials behave similarly but with unpredictable results of reactivity. For instance, natural materials will form biomaterials and become an integral part of the life cycle, whereas engineered materials will form toxins to the living objects. This forms the core of the question that should be asked in any future research. The unique feature of this technology is that the behavior of the matter is very different from what is well-known, commonly accepted, and generally understood. Laws related to physics are different from those on macroscale. Even though it is commonly perceived that the laws of quantum mechanics are applicable, recent research findings show that nanomaterials are beyond the scope of quantum mechanics, from both a scientific (Islam, 2014; Islam and Mokhatab, 2018) and philosophical perspective (Hornstein, 1981). At the nanoscale conventional forces like, gravity, or inertia do not play much role; instead, other forces, not apparent in macroscale, such as van der Waal’s forces, electrostatic, and magnetism, are more important. The problem is none of these forces are amenable to measurements and even their mere existence remains tentative. It is, however, understood that

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FIGURE 4.15

Generalized trend for size-dependent reactivity change of a material as the particle transitions from macroscopic (bulk-like) to subatomic. Reactivity can increase or decrease depending on the material and the chemical reaction involved. Source: Modified from Islam and Mokhatab (2018).

alteration of nano-properties can make metals harder, ceramics softer, alloys malleable as per design could be engineered to become harder or softer and mixtures with specifically designed properties could be achieved (du Plessis et al., 2022). New devices based on nanotechnology will be different from the conventional one as the governing laws and other properties are different. The main problem with nano devices is whether these kind of machines will operate at any hostile environment or not, as the shearing-off or melting of a single layer of atoms may alter the characteristics of the nanomachine. While this has been known for over a decade, little is done as to how to describe the real problem, or which theory would explain it. For static devices, the results are much promising than the devices with moving parts. For example, nanoelectronics will open a new horizon for smaller but faster computing that will go beyond the theoretical limits of current technology. New forms of memory and storage device with increased capacity and reliability will be achieved using single electron/molecular design. However, for moving nano machines as friction plays a vital role it may pose a big hurdle to overcome. However, manifestation of “superlubricity” or very low friction (Dienwiebel et al., 2004; Socoliuc et al., 2004) in some nanostructure shades some light too. Liu et al. (2012) identified the process, in which shearing a microscale lithographically defined graphite mesa led to the sheared section retracting spontaneously to minimize interface energy. They showed that the frictional forces involved are due to superlubricity, where ultralow friction occurs between incommensurate surfaces. The effect is remarkable because it occurs reproducibly under ambient conditions and over a contact area of up to 10 3 10 μm2, more than seven orders of magnitude larger than

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previous scanning-probe-based studies of superlubricity in graphite. It shows frictions and lubrication at atomic and mesoscale are ill-understood with today’s science. A new generation of sensors and imaging technology as a result of nanotechnology will help to deploy those at different places that are now inaccessible and/or infeasible with the current technology due to size and performance. Nanoscience is based on the fact that properties of materials change as a function of the physical dimension of that material, and nanotechnology takes advantage of this by applying selected property modifications of this nature to some beneficial endeavor. Agista et al. (2018) showed how nanotechnology is and will affect geosciences. In a similar fashion, we can predict the impact on petroleum industry. The magnetic, electrical, mechanical and chemical properties may be surprisingly different from the host material, apart from the physics of the material. Our macroscopic common sense may not apply to the nanoscale phenomenon. For example, water can pass through the hydrophobic carbon nanotubes (CNTs) (Hummer et al., 2001). Many fluids behave abnormally when confined in a space of nanometer dimensions. For example, simple organic liquids become solid-like when squeezed between two smooth surfaces into a film that is less than about five molecular layers thick. In contrast, if water is squeezed between two mica surfaces, only small changes in viscosity occur. The nature of the confining surfaces also has an effect. Depending on the nanotube dimension, nano-ice may be formed as well. Not to mention, nanophase behavior depends on the preparation process apart from the particle size (Roy et al., 2006). Liu, L. et al. (2006) showed that adding nanomaterials changes the rheology of the fluid. The dimension affects the behavior significantly. For example, the electrorheology (ER, change in viscosity due to applied electric field) effect of the raw material of TiO2 nanoparticles is very weak, while the ER fluid containing titanate nano-whiskers shows high yield stress. So, it is possible to change some of the material properties using nanoparticles or creating a new kind of catalyst, suspension, etc. It is also true that nanomaterials are ubiquitous and any colloidal liquid would show viscosity variation in nanoscale. This is demonstrated in Fig. 4.16 that shows how viscosity in nanoscale increases drastically as the sample size is reduced. With that, small addition of nanoparticles would alter the rheology of the liquid drastically. Such process unlocks great potentials for heavy oil upgrading or even downhole refining of petroleum products. Fig. 4.17 shows how viscosity of heavy oil is affected by different types of nanomaterials. The same facts can be used to understand how rock/fluid interaction would take place (Chiu et al., 2013). Recent developments in subatomic physics highlight the presence of optimum in terms of characteristic speed. Fig. 4.18 shows characteristic speed as a function of particle size. This is in harmony with universal order, in which the graph is continuous on both sides of the size spectrum. Both sides approach the speed of light (Khan and Islam, 2016). In Fig. 4.18, a dust speck represents reversal of speed versus size trend. For so-called subatomic particles, speed increases as the size decreases. Higgs boson is assigned a smaller value than quark but larger value than photon. This is done deliberately in order to float the notion that fundamental particle and finality in determining such particle is a spurious concept and the actual size of it is arbitrary. Note that these characteristic speeds are all a function of time. This also follows that reactivity is greater as size is decreased. Any chemical reaction is similar to any other irreversible mass/energy transfer, in which

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FIGURE 4.16 Variation in nano viscosity as a function of length ratio (probe size/particle size). Source: From Chiu et al. (2013).

FIGURE 4.17 Effect of particle type on sample viscosity at a fixed temperature (25 C) and particles size: top line, micron-sized iron; bottomline, micron-sized copper; midline, micron-sized iron oxide (III). Source: From Shokrlu (2013).

there is a quantum change. Such change is a characteristic feature of phase transfer, chemical reaction, or when a life begins (from nonorganic to organic) or ceases for an individual (from organic to nonorganic). In this process, life and death are triggers or bifurcation points as associated time functions change drastically. It should be noted that such transition is subjective and death of one entity only means death for that particular object. The time function, f(t) defines the pathway of any entity within the universal order. In Fig. 4.18, dust specks represent the most objects closest to stable and steady state. The pathway followed by dust specks is the one that is organic and beneficial to the ecosystem. In nanoscale reactivity increases and therefore the divergence between natural and artificial particles gains momentum. This divergence is similar to organic and nonorganic or living or dead object. Fig. 4.19 shows how the direction of a natural particle and its “orbit” is opposite to that of artificial particle. Unless long-term analysis is done, it is not possible

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FIGURE 4.18 Orbital speed versus size (not to scale). Source: From Islam (2014).

to observe the difference between these two types. Such observation is necessary in order to determine the true impact of a new material. To-date, research topics are more concerned about the short-term impacts that are little more than safety analysis. In this research, Khan and Islam’s (2007) criterion will be used to determine applicability of various nanomaterials and nanofluids and the long-term impacts thereof. History supports the notion that harmfulness of artificial was well-known or previous civilizations did not attempt to produce artificial products. Fig. 4.20 shows how important it is to distinguish between artificial process and natural process. As pointed out by Islam et al. (2010), every artificial chemical has created irreversible damage to the environment whereas every natural chemical led to global sustainability (Khan and Islam, 2016). The superflux of artificial started with Democritus’ model that was first accepted by Aristotle and later glamourized by scholars affiliated with the Roman Catholic church. While New Science claims that it has broken out of dogmatic cognition, in reality, every theory in New Science emerges from aphenomenal premises, much like atomism or dogma (Islam et al., 2012). A correct material property model should include all rheological properties as function of particle size that include memory effects (Hossain and Islam, 2009). Hossain and Islam, 2008 in order to capture the time function in its entirety. Experimental results with artificial nanomaterials suggest that a wide range of variation is expected. The key is to make best use of the variability. Fig. 4.21 shows how friction coefficient can vary with viscosity. It becomes more complex when viscosity is a function of time. Viscosity itself highlights

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FIGURE 4.19

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Natural artificial both act the same way, except for the time function.

FIGURE 4.20 Historically, natural objects were synonymous with sustainability. Source: From Khan and Islam (2012).

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FIGURE 4.21 Lubricity of various artificial

Coefficient of Friction

HEPES-Glycerol Mixtures PLL-g-PEG+HEPES-Glycerol Mixtures

10

-1

10

-2

10

-3

10

-4

10

1

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3 5 104 10 10 Speed X Viscosity

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fluids as a function of viscosity. Source: From Islam and Mokhatab (2018).

6

the level of interactions with the environment. For instance, for the same viscosity, natural material will improve the environmental health while artificial material will degrade it. The pores in mud rocks are in nanoscale. For petroleum reservoirs, the pore size distribution contains most, if not all, nanoscale pores. Therefore the flow of the reservoir fluids is surely somehow affected by the nanostructure, as the fluid flow behavior through nanopores is surprisingly different than from of through macro scale. For example, Majumder et al. (2005) showed that fluid flow through CNTs is four to five orders of magnitude faster than predicted by conventional fluid flow theory. Therefore, to fully understand the reservoir mechanism, we need to know the behavior of reservoir rock-fluid properties in nanoscale too. This knowledge will help to recover more from the reservoirs. Even, at least modification to the existing theories, if not new theories, is required to incorporate knowledge acquired from nanoscience. Hochella (2002) pointed out the remarkable impact of particle size on particle behavior and tried to explain it in terms of property-size dependence on electronic structure of matter. The interest in using nanoparticles in membrane structures mainly focuses on their assumed beneficial effect on fluxes and fouling resistance. Kim and Van der Bruggen (2010) reviewed potential applications of nanoparticles-enhanced membranes in general. They conclude that the use of nanoparticles in the development of low-fouling membranes allows for a high degree of control over membrane characteristics as well as the ability to produce ceramic membranes in the nanofiltration membrane range. A wide range of nanoparticle types are used, such as TiO2 (Sotto et al., 2011; Soroko and Livingston, 2009; Yang et al., 2007). Nanomaterials such as ZnO (Balta et al., 2012), Al2O3 (Yan et al., 2009; Yu et al., 2011), Au (Vanherck et al., 2011), zero-valent iron (ZVI) (Xu and Bhattacharyya, 2005), Pd (Tanaka et al., 2006) have been looked at. It would be interesting to use some of these materials in their natural state—the state that offers unconditional sustainability and environmental integrity. These membranes can be used for water treatment, oil
water separation and gas
gas separation. The gas
gas separation can be enhanced by impregnating with nanoliquids. According to Pendergast and Hoek (2011), the most promising functionalities in water treatment applications include zeolitic and catalytic nanoparticle-coated ceramic

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membranes, hybrid inorganic
organic nanocomposite membranes, and bioinspired membranes such as hybrid protein
polymer biomimetic membranes, aligned nanotube membranes, and isoporous block copolymer membranes. Surface diffusion is a ubiquitous phenomenon playing a highly important role both in natural and technological processes (Naumovets, 2005). Current refining processes use lots of toxic materials that create environmental havoc. Nanostructure may provide better insight of filtering. That, in turn, will provide us a way to use filters (natural or nano-engineered) in refining without or minimal use of toxic material. This knowledge will benefit other industrial process as well. New kind of catalysts will open new horizon too. For example, although gold does not behave as a catalyst in bulk form, nanoparticles of gold or other transition metals may be used as a substitute for platinum, where platinum is one of the most used catalyst in hydrocarbon reaction (Guczi, 2005). More recently, Shiju and Guliants (2009) reviewed progresses made in catalysts that use nanostructures. Noble metal nanoparticles such as Pt, Pd, Rh, Au, and their alloys with other metals have been extensively employed to catalyze a wide range of dehydrogenation, hydrogenation, and selective oxidation reactions of organic molecules. Novel approaches are still required to synthesize and characterize stable gold and other metal nanoparticles with tightly controlled sizes to further advance the knowledge of their unique size-dependent catalytic behavior. The bulk mixed metal oxides of vanadium, molybdenum, and other transition metals, such as the M1 phase for propane ammoxidation to acrylonitrile, have shown great promise as highly active and selective oxidation catalysts. However, fundamental understanding of surface molecular structure
reactivity relationships of these systems remains highly limited.

4.3 The separation and refining process Today, petroleum fluids are transported to refineries prior to any usage. Oil refineries are enormous complex processes. Fig. 4.22 shows major components involved in a refining process. The fundamental process of refining involves the breakdown of crude oil into its various components and the separation of them to sell as a value added product. Because each component loses its natural properties during the denaturing process, chemicals are added to restore original qualities. This is a typical chemical decomposition and resynthesis process that has been in practice in practically all sectors of the modern age, ranging from the plastic industry to pharmaceutical industries. Fig. 4.23 shows the major steps of a conventional refining process. The first step is transportation and storage. In the crude oil refining process, fractional distillation is the main process that separates oil and gas. For this process, the distillation tower is used, which operates at atmospheric pressure and leaves a residue of hydrocarbons with boiling points above 400 C and more than 70 carbon atoms in their chains. Small molecules of hydrocarbons have low boiling points, while larger molecules have higher boiling points. The fractionating column is cooler at the top than at the bottom, so the vapors cool as they rise. Fig. 4.24 shows the pictorial view of a fractional column. It also shows the ranges of hydrocarbons in each fraction. Each fraction is a mix of hydrocarbons and each fraction has its own range of boiling points and comes off at a different level in the tower. Petroleum

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FIGURE 4.22 The pathway followed by the refining process.

FIGURE 4.23 Major steps involved in a refining process.

refining has evolved continuously in response to changing consumer demands for better and different products, such as from aviation gasoline to jet fuel. Each requires various degrees of “refinement” to conform to specific needs of machineries that are designed according to certain “ideal” fluid behavior. Petroleum refining has evolved continuously in response to changing consumer demands for better and different products, such as from aviation gasoline to jet fuel. Each requires various degrees of “refinement” to conform to specific needs of machineries that are designed according to certain “ideal” fluid behavior. A summary of a detailed process flow chart for oil refining steps is presented in Table 4.2. The table also describes the different treatment methods for each of the refining phases. The third column in the above

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FIGURE 4.24 Pictorial view of fractional column.

table shows how the refining process can render natural petroleum fluids into toxic chemicals. If the heat source and catalysts used are products of unsustainable practices, their contact with petroleum fluids will result in unsustainable products. Unless this is recognized, further refinement of the process, for example, optimization of catalysts, automation of heating elements, blending of various additives, and corrosion protection, will not solve the sustainability problem. Catalysts used in processes that remove sulfur are impregnated with cobalt, nickel, or molybdenum, each of which is a toxic element, with far more impact on the environment than the sulfur in crude oil. During the separation process, sulfur from crude oil is removed only in exchange for traces of these catalysts. As discussed by Khan and Islam (2016), trace elements are not negligible and must be accounted for in determining long-term impacts. These trace elements will accompany the refined oil and will end up in combustion chambers, eventually polluting the CO2 emitted from a combustion engine. The inability of current detection techniques to identify these trace elements will not ensure that the pollution of CO2 does not take place. We will see in follow-up chapters that contaminated CO2 is not acceptable by plants or trees, which reject this strand of CO2. This process ends up contributing to the overall concentration of CO2 in the atmosphere, delaying natural consumption, and utilization of CO2 in the ecosystem. If the removal of sulfur is the objective, the use of zeolite can solve this problem. It is well known that naturally occurring zeolite has the composition to act as a powerful agent that would adsorb unwanted matters with high levels of adsorption, ion exchange, and catalytic actions (Primo and Garcia, 2014). However, numerous forms of synthetic catalysts have been developed each claiming to be optimized for a specific application.

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TABLE 4.2 Details of oil refining process and various types of catalyst used. Process

Description

Catalyst/heat/pressure used

Distillation processes

It basically relies on the difference in the boiling Heat point of various fluids. Density also has an important role to play in distillation. The Lightest hydrocarbon at the top and the heaviest residue at the bottom are separated.

Coking and thermal process

Coking unit converts heavy feedstocks into solid Heat coke and lower boiling hydrocarbon products that are suitable to offer refinery units to convert to higher value transportation fuel. This is a severe thermal cracking process to form coke. Coke contains high boiling point hydrocarbons and some volatiles that are removed by calcining at a temperature of 1095 C
1260 C. Coke is allowed sufficient time to remain in high-temperature heaters in insulated surge drums, hence, it is called delayed coking.

Thermal cracking The crude oil is subjected to pressure, and large Excessive heat and pressure molecules are broken into small ones to produce additional gasoline. The naphtha fraction is useful for making many petrochemicals. Heating naphtha in the absence of air makes the molecules split into shorter ones. Catalytic cracking

Catalytic cracking converts heavy oils into high Nickels, zeolites, acid-treated natural alumina silicates, amorphous and crystalline synthetic gasoline, less heavy oils, and lighter gases. silica
alumina catalyst. Paraffins are converted into C3 and C4 hydrocarbons. The benzene rings of aromatic hydrocarbons are broken. Rather than distilling more crude oil, an alternative is to crack crude oil fractions with longer hydrocarbons. Larger hydrocarbons split into shorter ones at low temperatures if a catalyst is used. This process is called catalytic cracking. The products include useful short-chain hydrocarbons.

Hydro processing

Hydroprocessing (325 C and 50 atm) includes both hydrocracking (350 C and 200 atm) and hydrotreating. Hydrotreating involves the addition of hydrogen atoms to molecules without actually breaking the molecule into smaller pieces and improves the quality of various products (e.g., by removing sulfur, nitrogen, oxygen, metals, and waxes and by converting olefins to saturated compounds). Hydrocracking breaks longer molecules into smaller ones. This is a more severe operation using higher heat and longer contact time. Hydrocracking reactors contain fixed, multiple catalyst beds.

Platinum, tungsten, palladium, nickel, and crystalline mixture of silica alumina; cobalt and molybdenum oxide on alumina nickel oxide, nickel thiomolybdate tungsten, nickel sulfide, vanadium oxides, and nickel thiomolybdate are used for sulfur removal, and nickel molybdenum catalyst is used for nitrogen removal.

(Continued)

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TABLE 4.2 (Continued) Process

Description

Catalyst/heat/pressure used

Alkylation

Alkylation or “polymerization” is the process of forming longer molecules from smaller ones. Another process is isomerization, in which straight chain molecules are made into higher octane branched molecules. The reaction requires an acid catalyst at low temperatures and low pressures. The acid composition is usually kept at about 50%, making the mixture very corrosive.

Sulfuric acid, or hydrofluoric acid, HF (1 C
40 C, 1
10 atm). Platinum on AlCl3/ Al2O3 catalyst is used as a new alkylation catalyst.

Catalytic reforming

This uses heat, moderate pressure, and fixed bed catalysts to turn naphtha, short carbon chain molecule fraction, into high-octane gasoline components—mainly aromatics.

Catalyst used is a platinum (Pt) metal on an alumina (Al2O3) base.

Treating Treating can involve chemical reactions and/or nonhydrocarbons physical separation. Typical examples of treating are chemical sweetening, acid treating, clay contacting, caustic washing, hydrotreating, drying solvent extraction, and solvent dewaxing. Sweetening compounds and acids desulfurize crude oil before processing and treat products during and after processing.

Conventionally, synthetic catalysts are used for enhancing the petroleum cracking process. Even when naturally occurring chemicals are used, they are acid-treated. With the acid being synthetically produced, the process becomes irreversibly contaminated. More recently, microwave treatment of natural materials is being proposed in order to enhance the reactivity of natural materials (Henda et al., 2005). With microwave heating not being a natural process, this treatment will also render the process unsustainable. However, such treatment is not necessary because natural materials, such as zeolite, clay, and others, do contain properties that would help the cracking process. Acid enhancing, if at all needed, can be performed with organic acid or acid derived from natural sources. Acid-function catalysts impregnated with platinum or other noble metals are used in isomerization and reformings. Research on this topic has focused on the use of refined heavy metal elements and synthetic materials). These materials are known carcinogens and have numerous long-term negative effects on the environment. In addition, the resulting products are aromatic oils, carcinogenic polycyclic aromatic compounds, or other hazardous materials, and they may also be pyrophoric. This becomes a difficult short-term problem. When such a problem is addressed, solutions that are no more sustainable are usually offered. For instance, in order to combat pyrophoricy, a patented technology uses aromatic hydrocarbons such as alkyl-substituted benzenes including toluene, xylene, and heavy aromatic naphtha. Heavy aromatic naphtha comprises xylene and higher aromatic homologs (Islam and Khan, 2019). The entire process spirals further down the path of unsustainability. Table 4.3 shows the various processes and products used during the refining process. Each of the above functions can also be performed with natural substitutes that are cheaper and benign to the environment. This list includes the following: zeolites, alumina, silica, various

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TABLE 4.3 Various processes and products in oil refining process. Conversion processes—unification Alkylation

Combining

Catalytic

Unit olefins and isoparaffins

Tower isobutane/ cracker olefin

Iso-octane (alkylate)

Grease compounding

Combining

Thermal

Combine soap and Lube oil, fatty oils acid, alky metal

Lubricating grease

Polymerizing

Polymerize

Catalytic

Unite 2 or more olefins

Cracker olefins

High-octane naphtha, petrochemical stocks

High oct. Reformate/ aromatic

Conversion processes—alteration or rearrangement Catalytic reforming

Alteration/ dehydration

Catalytic

Upgrade low octane naphtha

Coker/ hydrocracker naphtha

Isomerization

Rearrange

Catalytic

Straight chain to branch

Butane, pentane, Isobutane/pentane/ hexane hexane

Amine treating

Treatment

Absorption Remove acidic contaminants

Acid-free gases and Sour gas, HCs w/CO2, and H2S liquid HCs

Desalting

Dehydration

Absorption Remove contaminants

Crude oil

Desalted crude oil

Drying

Treatment

Abspt/ therm

Liq Hcs, LPG, alky feedstk

Sweet and dry hydrocarbons

Furfural extraction

Solvent extraction

Absorption Upgrade mid Cycle oils and distillate and lubes lube feedstocks

High-quality diesel and lube oil

Catalytic

Treatment processes

Hyfrodesulfarization Treatment

Remove H2O and sulfur compounds

Remove sulfur, contaminants

High-sulfur residual/gas oil

Desulfurized olefins

Hydrotreating

Hydrogenation Catalytic

Remove impurities, saturate HCs

Residuals, cracked HCs

Cracker feed, distillate, lube

Phenol extraction

Solvent extraction

Abspt/ therm

Improve vise. index, color

Lube oil base stocks

High-quality lube oils

Solvent deasphalting

Treatment

Absorption Remove asphalt

Vac. tower residual, propane

Heavy lube oil, asphalt

Solvent dewaxing

Treatment

Cool/filter Remove wax from lube stocks

Vac. tower lube oils

Dewaxed lube basestock

Solvent extraction

Solvent extr.

Abspt/ precip.

Separate unsat. oils

Gas oil, reformate, distillate

High-octane gasoline

Sweetening

Treatment

Catalytic

Untreated Remove H2S, convert mercaptan distillate/ gasoline

High-quality distillate/gasoline (Continued)

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TABLE 4.3 (Continued) Process name

Action

Method

Purpose

Feedstock(s)

Product(s)

Fractionation processes Atmospheric distillation

Separation

Thermal

Separate fractions

Desalted crude oil

Gas, gas oil, distillate, residual

Vacuum distillation

Separation

Thermal

Separate w/o cracking

Atmospheric tower residual

Gas, gas oil, lube, residual

Conversion processes—decomposition Catalytic cracking

Alteration

Catalytic

Upgrade gasoline

Gas oil coke, distillate

Gasoline, petrochemical feedstock

Coking

Polymerize

Thermal

Convert vacuum residuals

Gas oil coke, distillate

Gasoline, petrochemical feedstock

Hydrocracking

Hydrogenate

Catalytic

Convert to lighter HCs

Gas oil, cracked oil residual

Lighter higher quality products

Hydrogen steam reforming

Decompose

Catalytic/ thermal

Produce hydrogen

Desulfurized gas, O2, steam

Hydrogen, CO, CO2

Steam cracking

Decompose

Thermal

Crack large molecules

Atm tower, heavy fuel/ distillate

Cracked naphtha, coke, residual

Visbreaking

Decompose

Thermal

Reduce viscosity

Atm tower residual

Distillate tar

biocatalysts, and enzymes in their natural state. The use of bacteria to decompose large hydrocarbon molecules offers an attractive alternative because the process is entirely sustainable (as per the Khan and Islam (2007) criterion). Khan and Islam (2007a) also suggest the use of gravity segregation from distillate lighter components to heavier ones. The use of solar heating, in conjunction with heating from flares that are available in the oil field, will bring down the heating cost and make the process sustainable. Tables 4.4 and 4.5 (enumerate the primary emissions at each activity level (Islam and Khan, 2019). There are seven primary air release emissions and 23 primary hazardous/ solid wastes. The primary hazardous/solid wastes include the following: 1,2,4-trimethylbenzene, 1,3butadiene, ammonia, anthracene, benzene, copper, cumene, cyclohexane, diethanolamine, ethylbenzene, ethylene, hydrofluoric acid, mercury, metals, methanol, naphthalene, nickel, polycyclic aromatic hydrocarbons, phenol, propylene, sulfuric acid aerosols or toluene, vanadium (fumes and dust), and xylene. The most important resource in the refinery process is energy. The refining process uses a lot of energy. Typically, approximately 2% of the energy contained in crude oil is used for distillation. The efficiency of the heating process can be increased drastically by combining direct solar heating (with nonengineered thermal fluid) with direct fossil fuel burning. The advantage of this process is a gain in global efficiency as well as environmental benefit. It is estimated that the total energy requirement for petroleum refining can be

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TABLE 4.4 Emissions from refinery. Materials transfer and storage Air releases: VOCs (polluted with catalysts and other toxic additives) Hazardous/solid wastes: anthracene, benzene, 1,3-butadiene, cumene cyclohexane, ethylbenzene, ethylene, methanol, naphthalene, phenol, PAHs, propylene, toluene, 1,2,4-trimethylbenzene, xylene (polluted with catalysts and other toxic additives) PAHs, Polycyclic aromatic hydrocarbons.

TABLE 4.5 Primary wasters from oil refinery. Cracking/coking

Alkylation and reforming

Sulfur removal

Air releases: carbon monoxide, nitrogen oxides, particulate matter, sulfur dioxide, VOCs

Air releases: carbon monoxide, nitrogen oxides, particulate matter, sulfur dioxide, VOCs

Air releases: carbon monoxide, nitrogen oxides, particulate matter, sulfur dioxide, VOCs

Hazardous/solid wastes, wastewater: ammonia, anthracene, benzene, 1,3butadiene, copper, cumene, cyclohexane, ethylbenzene, ethylene, methanol, naphthalene, nickel, phenol, PAHs, propylene, toluene, 1,2,4trimethylbenzene, vanadium (fumes and dust), xylene

Hazardous/solid wastes: ammonia, benzene, phenol, propylene, sulfuric acid aerosols or hydrofluoric acid, toluene, xylene Wastewater

Hazardous/solid wastes: ammonia, diethanolamine, phenol, metal wastewater

PAHs, Polycyclic aromatic hydrocarbons.

reduced to less than 0.5% of the energy contained in crude oil by designing the heating systems with a zero-waste scheme, as outlined by Khan and Islam (2016). A number of procedures are used to turn heavier components of crude oil into lighter and more useful hydrocarbons. These processes use catalysts or materials that help chemical reactions without being used up themselves. Table 4.6 shows different toxic catalysts and base metals. Refinery catalysts are generally toxic and must be replaced or regenerated after repeated use, turning used catalysts into a waste source. The refining process uses either sulfuric acid or hydrofluoric acid as catalysts to transform propylene, butylene, and/or isobutane into alkylation products, or alkylate. Vast quantities of sulfuric acid are required for the process. Hydrofluoric acid (HF), also known as hydrogen fluoride, is extremely toxic and can be lethal. Using catalysts with fewer toxic materials significantly reduces pollution. Eventually, organic acids and enzymes, instead of catalysts, must be considered. Thermal degradation and slow reaction rates are often considered to be biggest problems of using organic acid and catalysts. However, recent discoveries have shown that this perception is not justified. There are numerous organic products and enzymes that can withstand high temperatures, and many of them induce fast reactions. The same principle applies to other materials, for example, corrosion inhibitors, bactericides, etc. Often, toxic chemicals lead to very high corrosion vulnerability, and even more toxic corrosion inhibitors are required. The whole process spirals down to a very unstable process, which can be eliminated with the new approach (Al-Darbi et al., 2002) (Tables 4.7 and 4.8).

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TABLE 4.6 Chemicals used in refining. Chemicals used in refining

Purpose

Ammonia

Control corrosion by HCL

Tetraethyl lead (TEL) and tetramethyl lead (TML)

Additives to increase the octane rating

Ethyl tertiary butyl ether (ETBE), methyl tertiary butyl ether (MTBE), tertiary amyl methyl ether (TAME)

To increase gasoline octane rating and reduce carbon monoxide

Sulfuric Acid and Hydrofluoric Acid

Alkylation processes, some treatment processes.

Ethylene glycol

Dewatering

Toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone, methylene chloride, ethylene dichloride, sulfur dioxide

Dewaxing

Zeolite, aluminum hydrosilicate, treated bentonite clay, fuller’s earth, bauxite, and silica
alumina

Catalytic cracking

Nickel

Catalytic cracking

Granular phosphoric acid

Polymerization

Aluminum chloride, hydrogen chloride

Isomerization

Imidazolines and Surfactants Amino Ethyl Imidazoline Hydroxy-Ethyl Imidazoline Imidazoline/Amides Amine/Amide/DTA

Oil soluble corrosion inhibitors

Complex Amines Benzyl Pyridine

Water soluble corrosion inhibitors

Diamine Amine Morpholine

Neutralizers

Imidazolines sulfonates

Emulsifiers

Alkylphenolformaldehyde, polypropylene glycol

Desalting and emulsifier

Cobalt Molybdate, platinum, chromium alumina AlCl3-HCl, copper pyrophosphate

TABLE 4.7 Pollution prevention options for different activities in material transfer and storages. Cracking/coking

Alkylation and reforming

Using catalysts with fewer toxic materials reduces the pollution from “spent” catalysts and catalyst manufacturing.

Using catalysts with fewer toxic materials reduces the pollution from “spent” catalysts and catalyst manufacturing.

Sulfur removal

Cooling

Use “cleaner” crude oil, containing less sulfur and fewer metals. Using oxygen rather than air in the Claus plant reduces the amount of hydrogen sulfide and nitrogen compounds produced.

Ozone or bleach should replace chlorine to control biological growth in cooling systems Switching from water cooling to air cooling could reduce the use of cooling water by 85%.

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TABLE 4.8 Catalysts and materials used to produce catalysts base metals and compounds. Names of catalysts

Name of metals base

Activated alumina, Amine, Ammonia, Anhydrous hydrofluoric acid Antifoam agents—for example, oleyl alcohol or Vanol, Bauxite, Calcium chloride, Catalytic cracking catalyst, Catalytic reforming catalyst, Caustic soda, Cobalt molybdenum, Concentrated Sulfuric acid, Demulsifiers—for example, Vishem 1688, Dewaxing compounds (catalytic)—for example, P4 Red, wax solvents Diethylene glycol, Glycol—Corrosion inhibitors, Hydrogen gas, Litharge, Na MBT (sodium 2-mercaptobenzothiazole)—glycol corrosion inhibitor (also see the taxable list for Oil Refining—Corrosion inhibitors), Na Cap—glycol corrosion inhibitor (also see the taxable list for Oil Refining—Corrosion inhibitors), Nalcolyte 8103, Natural catalysts—being compounds of aluminum, silicon, nickel, manganese, iron, and other metals, Oleyl alcohol—antifoam agent, Triethylene glycol, Wax solvents—dewaxing compounds.

Aluminum (Al), Aluminum Alkyls, Bismuth (Bi), Chromium (Cr), Cobalt (Co), Copper (Cu), Hafnium (Hf), Iron (Fe), Lithium (Li), Magnesium (Mg), Manganese (Mn), Mercury (Hg), Molybdenum (Mo), Nickel (Ni), Raney Nickel, Phosphorus (P), Potassium (K), Rhenium (Re), Tin (Sn), Titanium (Ti), Tungsten (W), Vanadium (V), Zinc (Zn), Zirconium (Zr), and More.

4.4 Additives and their functions Oil refining and natural gas processing are very expensive processes in terms of operation and management. These operations involve the use of several chemicals and catalysts that are very expensive. Moreover, these catalysts and chemicals pose a great threat to the natural environment including air and water quality. Air and water pollution ultimately have impacts on the health of humans, animals, and plants. For instance, the use of catalysts, such as lead, during crude oil refining to produce gasoline has been a serious environmental problem. Burning gasoline emits toxic gases containing lead particles, and the oxidation of lead in the air forms lead oxide, which is a poisonous compound affecting the lives of every living thing. Heavy metals such as mercury and chromium and the use of these metals in oil refining are major causes of water pollution that eventually permeates the entire ecosystem. Consider the consequences of some of these chemicals.

4.4.1 Platinum It is well known that platinum salts can induce numerous irreversible changes in human bodies, such as DNA alterations (Jung and Lippard, 2005). In fact, an entire branch

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of medical science evolves around exploiting this deadly property of platinum compounds in order to manufacture pharmaceutical drugs that are used to attack the DNA of cancer cells (Lippard, 1994). It is also known that platinum compounds cause many forms of cancer. Once again, this property of platinum is used to develop pharmaceutical drugs that could possibly destroy cancer cells (Volckova et al., 2003). Also, it is well known that platinum compounds can cause liver damage (Stewart et al., 1985). Similar damage to bone marrow is also observed. Platinum is also related to hearing loss (Rybak, 1981). Finally, potentiation of the toxicity of other dangerous chemicals in the human body, such as selenium, can lead to many other problems. The above are immediate concerns to human health and safety. Consider the damage to the environment that might be incurred through vegetation and animals (Kalbitz et al., 2008). It is already known that platinum salts accumulate at the root of plants, from which they can easily enter the food chain, perpetually insulting the environment. In addition, microorganisms can play a role to broaden the impact of platinum. This aspect of ecological study has not been performed as of now. In the meantime, platinum is touted as a tool for remedying air pollution. Since 1976 in the United States, Canada, and Japan, and later in other countries, the exhaust system of gasoline-powered cars has been equipped with catalytic converters containing Pt and/or Pd and/or Rh. This has resulted in a very significant decrease in urban air pollution for various chemical species such as NOx, CO, and hydrocarbons. While this “success” is celebrated, New Science cannot fathom what toll this “success.” There has, however, been concern that their ever-increasing use might lead to platinum group metals (PGMs) becoming widely dispersed in the environment. From the analysis of Pt, Pd, and Rh in central Greenland recent snow and ancient ice using the ultrasensitive inductively coupled plasma sector field mass spectrometry technique, Barbante et al. (2001) showed that the concentrations of these metals in snow dated from the mid-1990s are indeed B40 2 120 times higher than in ice dated from 7000 years ago. The fact that such an increase is observed far away from populated areas at a high-altitude location indicates there is now a large-scale contamination of the troposphere of the Northern Hemisphere for PGMs. Pt/ Rh mass ratio in the most recent snow samples is close to the same ratio documented for catalytic converter exhausts in a recent study, which suggests that a large fraction of the recent increase for Pt and Rh might originate from automobile catalytic converters. At the same time, other publications indicate that even the use of platinum in catalytic converters has created a massive problem. In as early as 2001, Barbante et al. discussed the long-term impact of platinum and other precious metals on the air pollution. They reported that the planet has been covered with a fine layer of osmium due largely to efforts to clean up car exhausts, according to a global survey of rainwater. Externally, these are not considered to be harmful, mainly because they fall under the realm of “intangibles” the science of which is beyond the current expertise of New Science (Jones, 2009). These pollutants come from cars that have been fitted with catalytic converters to keep nitrogen oxides and carbon monoxide out of the air. This cuts down on smog and has huge health benefits. But catalytic converters created a demand for platinum, which has its own environmental impact. The smelting of platinum can release metals into the air, for example—particularly osmium tetroxide, the impact of which is likely to be more significant than other pollutants that are featured prominently. Typically, it is the tangible

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aspect that alerts scientists and regulatory agencies to issue new measures. However, we make the point that focusing on tangibles will not resolve the crisis as the most important aspect of pollution takes place in intangible forms1 and by the time scientists can detect these forms (e.g., with new detection tools), the problem has already gone out of control. One such example is offered by recent work of Chen et al. (2009). Chen et al. (2009) reported that the osmium concentration in surface ocean water has risen unexpectedly. Osmium is one of the rarer elements in seawater, with a typical concentration of  10 3 10215g g21 (5.3 3 10214 mol/kg). The osmium isotope composition (187Os/188Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (  1.3) and mantle/cosmic dust (  0.13). Chen et al. (2009) showed that the 187 Os/188Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected ( . 1), but similar to the isotope composition of ores (  0.2) that are processed to extract platinum and other metals to be used primarily in automobile catalytic converters. Present-day surface seawater has a lower 187Os/188Os ratio (  0.95) than deep waters, suggesting that human activities have altered the isotope composition of the world’s oceans and impacted the global geochemical cycle of osmium. The contamination of the surface ocean is particularly remarkable given that osmium has few industrial uses. The pollution may increase with growing demand for platinum-based catalysts. This outcome was not certainly expected from platinum use.

4.4.2 Cadmium Cadmium is considered to be a nonessential and highly toxic element to a wide variety of living organisms, including man, and it is one of the widespread pollutants with a long biological half-life Goyer (2004). A provisional, maximum, tolerable daily intake of cadmium from all sources is 1
1.2 g/kg body mass (Bortoleto et al., 2004) and is recommended by FAO-WHO jointly. This metal enters the environment mainly from industrial processes and phosphate fertilizers and is transferred to animals and humans through the food chain. Cadmium is very hazardous because humans retain it strongly, particularly in the liver (half-life of 5
10 years) and kidney (half-life of 10
40 years). The symptoms of cadmium toxicity produced by enzymatic inhibition include hypertension, respiratory disorders, damage of kidney and liver, osteoporosis, formation of kidney stones, and others (Satarug et al., 2017). Environmental, occupational, or dietary exposure to Cd(II) may lead to renal toxicity, pancreatic cancer, or enhanced tumor growth (Satarug et al., 2017). The safety level of cadmium in drinking water in many countries is 0.01 ppm, but many surface waters show higher cadmium levels. Cadmium can kill fish in one day at a concentration of 10 ppm in water, whereas it can kill fish in 10 days at a concentration of 2 ppm. Taken up in excess by plants, Cd directly or indirectly inhibits physiological processes, such as respiration, photosynthesis, cell elongation, plant
water relationships, nitrogen metabolism, and mineral nutrition, all of which result in poor growth and low biomass. It was also reported that cadmium is more toxic than lead in plants (Sanita di Toppi and Gabbrielli, 1999). In particular, Sanita˚ di Toppi and Gabbrielli (1999) summarized the state 1

It means that the main players in creating pollution are below the detection level and behave like undetected cancer cells, whose manifestation in tangible form comes too late for intervention, let alone mitigation.

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of the art of higher plant responses to cadmium. The principal mechanisms reviewed included phytochelatin-based sequestration and compartmentalization processes, as well as additional defense mechanisms, based on cell wall immobilization, plasma membrane exclusion, stress proteins, stress ethylene, peroxidases, metallothioneins, etc. An analysis of data taken from the international literature has been carried out, in order to highlight possible “qualitative” and “quantitative” differences in the response of wild-type (nontolerant) plants to chronic and acute cadmium stress. The dose
response relationships indicate that plant response to low and high cadmium level exposures is a very complex phenomenon, in which cadmium evokes a number of parallel and/or consecutive events at molecular, physiological, and morphological levels. They postulated that above all in response to acute cadmium stress, various mechanisms might operate both in an additive and in a potentiating way. Thus they called for a holistic and integrated approach to study of the response of higher plants to cadmium. While cadmium detoxification is a complex phenomenon, authors found tolerance to cadmium in mine plants or in plant systems artificially grown under long-term selection pressure, exposed to high levels of cadmium to be a linear process, possibly involving only monogenic/oligogenic control. They concluded that following a “pyramidal” model, (adaptive) tolerance is supported by (constitutive) detoxification mechanisms, which in turn rely on (constitutive) homeostatic processes. The presence of Cd leads to long-term adaptation mode and is found to affect long-term selection pressure, which may increase the frequency of one or a few tolerance gene(s). It is to be noted that the cadmium that was used by these researchers was that of refined kind, meaning they are not in their natural form, in which case it would cause little harm in low concentration and more importantly could be expelled from the organic system in case the concentration is too high for absorbance. In engineering terms, this behavior can be explained by metal-organic framework (MOF) materials, which are related to organic chemistry, inorganic chemistry, polymeric materials, physics, crystal engineering and topology, and other scientific fields. In the context of Climate change, MOF plays an important role in gas storage, gas purification, and as such as can offer an explanation why a small amount of cadmium can render a huge volume of CO2 unacceptable to the plants and trees, thus releasing them in the atmosphere as “tainted.” This tainted CO2 is the main cause of global increase in the CO2. It is known that carboxylic acid ligands can form multifunctional complexes with many kinds of metals. Zhang et al. (2016) synthesized nine new tetranuclear centrosymmetric linear complexes that are called tetranuclear complexes. Magnetic studies reveal that both DyIII-based complexes (3 and 8) exhibit single-molecule magnet (SMM) behavior under a zero dc field. Furthermore, complex 3 presents one relaxation process under a zero dc field, while application of an external dc field (1500 Oe) induces multi-relaxation signals of the ac magnetic susceptibility. This study showed a strong link between Cd (of artificial origin) and distortion of the magnetic field, which can have fundamental impact on the way these molecules interact with carboxyl groups. Zhao et al. (2018) used a new cadmium complex, [Cd2(dcpa) 2H2O]n H2O (1), which was synthesized by hydrothermal reaction based on the multiple acid ligand 4-(2,5-dicarboxyphenoxy)phthalic acid (H4-dcpa). Single crystal X-ray diffraction analysis reveals that 1 is a three-dimensional structure with pores. The result of X-ray diffraction analysis revealed that the complex, with a formula of Cd2 C16H12O12, crystallizes in the triclinic



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system, space group P-1. The asymmetric unit consists of two Cd ions, one dcpa ligand, and three water molecules (O3, O11, and O12) in the lattice. As depicted in Fig. 4.25A, Cd1 is surrounded by five O atoms (O1, O2, O5B, O7C, and O9C) from a dcpa ligand and one O atom (O3) from water; Cd2 is surrounded by five O atoms (O4A, O5A, O8D, O10, and O10E) from a dcpa ligand and one O atom (O11) from water. The coordination geometry can be described as a distorted octahedron. The O
Cd
O angles are in the range of 53.06(14) to 159.75(17) degrees. The Cd
O bond lengths are in the range of 2.244(4)
2.474

(A)

c

b

a

FIGURE 4.25

(A) Coordination environment of Cd in complex 1; Symmetry code: A: x, 1 1 y, z; B: 1 2 x, 1 2 y, 2 2 z; C: x, y, 1 1 z; D: 21 1 x, y, z; E: 2 x, 2 2 y, 1 2 z; (B) Rod-shaped secondary building unit of complex; (C) Threedimensional network structure; Hydrogens are omitted for clarity.

O9C

O7C

O3

Cd1

O4A O12 O5A O8D

O5B O2

O1

O11 Cd2 O6

O8

O10E O10

O4 O5 (B)

O7

O9

O C Cd

c

a

O C Cd

(C) b

a c

O C Cd

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˚ ; the bond lengths are within the normal range. The neighboring Cd ions were linked (4) A by the carboxylate groups along the a-axis to form a rod-shaped secondary building unit (SBU) (Fig. 4.25B). The adjacent SBUs were further linked by the dcpa ligand to form a three-dimensional network structure (Fig. 4.25C). The fluorescence test results show that the complex has excellent blue fluorescence. The adsorption of nitrogen and carbon dioxide gas test results show that the complex has adsorption effects on carbon dioxide. This is of significance vis-a`-vis greenhouse gases. N2 and CO2 adsorption measurements (up to 1 bar) were performed on an Autosorb-3.0 (Quantachrome) volumetric analyzer (Fig. 4.26). The solid-state fluorescence spectra of H4-dpca and 1 were recorded at room temperature on a FLS980 spectrophotometer under an excitation of 320 and 260 nm, respectively. Fig. 4.27A shows that H4dpca itself has a weak emission at around 468 nm. Complex 1 shows a strong emission peak at 350 nm; the complex formed has a large antistock’s shift of about 118 nm. This phenomenon is attributed to the intramolecular charge-transfer effect caused by Cd coordination. In other words, the blue shift of the complex should be attributed to formation of the dpca
Cd coordination complex that brings about the change of the electronics of dpca. The coordination interaction between Cd and dcpa will reduce FIGURE 4.26

Structure of H4 dcpa.

FIGURE 4.27

(A) Emission spectra H4 dpca and 1; (B) CIE chromaticity diagram of H4 dpca (A) and 1 (B). Source: From Zhao et al. (2018).

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the electron-withdrawing ability of the oxygen atoms, lower the electron density of dcpa, shift the frontier orbital level, and thus result in the blue shift of absorption as well as fluorescence emission. At the same time, the fluorescence intensity of the complex is eight times that of the ligand. The CIE chromaticity indicates that the position of the ligand H4dpca is (0.02, 0.23), but that of the complex is (0.15, 0.05), and from the CIE chromaticity diagram the great blue shift of the complex can be directly seen. The enhancement of luminescence in the complex is attributed to several factors. First, the conjugation effect of the new system was enhanced after the coordination reaction, which effectively increases the rigidity of the ligand and reduces the loss of energy by radiationless decay. At the very minimum, this means a change in the natural frequency of ligand. Secondly, organic ligands have a high UV absorption coefficient; after the complex was formed, energy absorbed by the dpca will efficiently transfer to the Cd ion and the results lead to a high fluorescence efficiency of the complex. Due to its porous structure and structural rigidity, an N2 adsorption experiment at 77K and CO2 adsorption at 273K in an ice-water bath were performed to evaluate the porosity of 1. The pore diameter of the complex is 3.814 nm as measured by Autosorb-3.0 (Quantachrome) volumetric analyzer, and the total ˚ 3 per unit cell accessible volume of the fully desolvated complex 1 is ca. 15.1% (863.2 A vol), calculated using the PLATON program. As shown in Fig. 4.28A, the complex has a weak adsorption effect on nitrogen. The experimental results show that the isotherm presented a typical type I curve, which is characteristic of microporous materials. As is seen in Fig. 4.28B, the CO2 adsorption experimental results show that the adsorption amounts of CO2 increase abruptly over the low-pressure range, up to 14 cm3/g (STP) at 0.2 atm and finally up to 18 cm3/g at 1 atm. It can be seen from the adsorption curve that the carbon dioxide and the complex have a strong interaction. Also, it can be seen from the desorption curve that desorption of carbon dioxide has some hysteresis. It means that the organic body will retain part of the chemical but will release enough to the CO2 that will remain “tainted” and thus unabsorbable by the organic system.

FIGURE 4.28 (A) The N2 adsorption/desorption isotherms of 1 at 273K (Zhao et al., 2018). (B) CO2 adsorption isotherms of 1 at 273K (Zhao et al., 2018).

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4.4.3 Lead Lead (II) is a highly toxic element to humans and most other forms of life. Children, infants, and fetuses are at particularly high risk of neurotoxic and developmental effects of lead. Lead can cause accumulative poisoning, cancer, and brain damage, and it can cause mental retardation and semipermanent brain damage in young children (Sultana et al., 2021). At higher levels, lead can cause coma, convulsion, or even death. Even low levels of lead are harmful and associated with a decrease in intelligence, stature, and growth. Lead enters the body through drinking water or food and can accumulate in the bones. Lead has the ability to replace calcium in the bone to form sites for long-term release (NorbergKing et al., 2006). The Royal Society of Canada reported that human exposure to lead has harmful effects on the kidney, the central nervous system, and the production of blood cells (Health Canada, 2013). In children, irritability, appetite loss, vomiting, abdominal pain, and constipation can occur (Yule et al., 1981). Animals ingest lead via crops and grasses grown in contaminated soil. Lead ingestion by women of childbearing age may impact both the woman’s health (Lustberg and Silbergeld, 2002) and that of her fetus, for ingested lead is stored in the bone and released during gestation (Gomaa et al., 2002). Conventional analysis does not reveal how lead can affect the nature of carbon dioxide or pollute the air. However, it is known that metal electrodes such as Cu, Pb, and Zn have been extensively employed in the electrochemical reduction of CO2. Depending on the metal used as cathode the final reaction products can vary considerably. This wide range of end products extends from hydrocarbons (methane, propane, ethylene, etc.) to oxygenated molecules, the most important of which are methanol, ethanol, and formic and oxalic acids. The reaction product distribution is very sensitive to various parameters such as applied potential, buffer strength and local pH, local CO2 concentration, CO2 pressure and the surface crystal structure of the electrode. The metals which have been found to most effectively catalyze CO2 reduction are those with a small number of electrons in the sp orbital and/or full d-orbitals. Examples of these include In, Pb, Cu, and Pd. They all reduce CO2 into carbon monoxide. Any of these reactions can poison the CO2 in the atmosphere. Carbon dioxide can be reduced to a wide range of end products. Each of these paths from CO2 to a particular product can be described as one of many competing “overall” reactions. The extent to which each progresses will depend on the metal catalyst, the electrolyte, and the cathode potential. Overall reactions are, however, a series of intermediate steps with competing reactions at each of these steps. Depending on the nature of the metal catalyst (natural state or artificial state), it is possible therefore that an overall reaction with a very positive open circuit potential, may not occur to a significant extent within a particular system. This will be the case if one of the intermediate steps does not occur to a significant extent, there being a more favored alternative reaction at that point. Chaplin and Wragg (2003) conducted electroreduction of carbon dioxide in aqueous and alkaline medium having hydrogenocarbonate ions as the predominant species in solution (pH 5 8.6 after bubbling CO2 in a 0.1 M NaOH solution). Taking into account the bands of species present in various spectra obtained with in situ IR reflectance spectroscopy, they proposed a reaction mechanism of selective hydrogenation of HCO32 to HCOO2. The disappearance of the band ascribed to CO2 when applying a cathodic electrode potential gives evidence that CO2 is not absorbed nor is it the electroreducible species on the lead

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electrode surface. Accordingly, formate was the exclusive organic species identified from HCO32 reduction during chronoamperometry/FTIRS experiments at 21.6 V versus SCE in aqueous medium. This study was significant because it related cathode properties in terms of the electron configuration of the metal catalysts present within the cathode, the adsorption/desorption properties of which can be predicted from these electron configurations. This allows predictions to be made as to which metal groups are likely to produce the longest lasting impact on the environment. There has long been an interest in the electroreduction of CO2 in order to make carbonbased compounds, and there have been parallels drawn between this and photosynthesis, albeit being the unnatural version of it. In their review of the topic, Jitaru et al. (1997) refer to papers, which review over 100 years of work on the subject. The review concludes that CO2 represents an infinite source of carbon that can be generated into methanol, ethanol, aldehydes, methane, ethylene, formic and oxalic acids. An alternative option is to develop a process that will produce a useful ratio of CO to H2 (i.e., Syngas). The growing promise of electrochemical methods is leading to many papers and patents. Much work is also ongoing on photocatalytic reduction. Carbon dioxide can be reduced to a wide range of end products. Each of these paths from CO2 to a particular product can be described as one of many competing “overall” reactions. The extent to which each progresses will depend on the metal catalyst, the electrolyte, and the cathode potential. Each overall reaction has its own open circuit potential and, for any given system, its own “overpotential against current density” profile. Overall reactions are, however, a series of intermediate steps with competing reactions at each of these steps. It is possible therefore that an overall reaction with a very positive open circuit potential, may not occur to a significant extent within a particular system. This will be the case if one of the intermediate steps does not occur to a significant extent, there being a more favored alternative reaction at that point. Some of the common reduction products are shown in Table 4.9. The competing intermediate reactions and resulting products can be most easily shown in a branching form. At each point, competing reactions create different branches. Eventually, end products can be grouped together according to what intermediate species they have in common. In Fig. 4.29, each competing reaction is given a reference letter. Many of the reaction paths are described in differing ways by different workers, for example, path B is frequently described as being a reaction between CO2ad and either Had or H2Oad. Innocent et al. (2010) formulated the reduction mechanism of the synthesis of formate from hydrogenocarbonate on lead electrode in alkaline solution. Taking into account the bands observed in spectra the various analyses focused on a selectivity of the reaction toward formate. The following hydrogenocarbonate reduction formulation was assumed. The first step is the reduction of the solvent, as shown by Chaplin and Wragg (2003): Pb 1 H2 O 1 e2 -Pb 2 Hads 1 HO2

(4.15)

Then the adsorption of hydrogenocarbonate at the lead sites could be written: ð4:16Þ

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TABLE 4.9 Equilibrium potentials for various CO2 electroreduction reactions. E /V 2CO2 1 2H1 1 2e2 -H2 C2 O4 1

20.475 20.199

2

CO2 1 2H 1 2e -HCOOH 1

CO2 1 2H 1 2e2 -CO 1 H2 O

20.109

CO2 1 4H1 1 4e2 -HCHO 1 H2 O

20.071

CO2 1 6H1 1 6e2 -CH3 OH 1 H2 O

10.030

CO2 1 8H1 1 8e2 -CH4 1 2H2 O

10.169

From Jitaru et al. (1997).

FIGURE 4.29 CO2 reduction routes commonly proposed for an acid system. Source: From Chaplin and Wragg (2003).

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Hydrogenation then occurs by the interaction between two adsorbed species:

ð4:17Þ

ð4:18Þ

This assumed mechanism is almost analogous to that reported by Jitaru et al. (2003) for the “sp” group metal cathodes that we discussed. Additional evidences were provided herein, with the adsorbed species obtained by in situ FTIR spectroscopy. Actually, potential-dependent shifts of HCO32ads (30 cm21/V) and HCOO2ads (26 cm21/V) were found in Figs. 4.30 and 4.31, which denotes weak adsorptions on lead electrode in comparison with those obtained with COL on Pt (45 cm21/V).

(A)

(B) 1397 cm-1

-1.5 V vs. SCE

0.05%

-1.6 V vs. SCE -1.0 V vs. SCE

-1.7 V vs. SCE

1639 cm-1

1388 cm-1

-1.2 V vs. SCE

∆R/R

∆R/R

-1.1 V vs. SCE

0.5% -1.3 V vs. SCE 1104 cm-1

1631 cm-1

1383 cm-1 -1.4 V vs. SCE

-1.45 V vs. SCE 1635 cm-1

1000 1250 1500 1750 2000 2250 2500 Wavenumber (cm-1)

-1.8 V vs. SCE

1000 1250 1500 1750 2000 2250 2500 Wavenumber (cm-1)

FIGURE 4.30 SPAIR spectra on a Pb electrode after bubbling CO2 in 0.1 M NaOH until pH 5 8.6; ΔR/R 5 (RE2 2 RE1)/RE1, where the “reference” spectrum, RE1, was taken at E 5 21.8 V versus SCE. (A) Electrode potential from 21.0 to 21.45 V versus SCE. (B) Electrode potential from 21.5 to 21.8 V versus SCE. Source: From Chaplin and Wragg (2003).

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FIGURE 4.31 SPAIR spectra on a Pb

1635 cm-1

1%

∆R/R

1632 cm-1

electrode after bubbling CO2 in 0.1 M NaOH until pH 5 8.6; ΔR/R 5 (RE2 2 RE1)/ RE1, where the “reference” spectrum, RE1, was taken at E 5 21.0 V versus SCE. Source: From Chaplin and Wragg (2003).

1629 cm-1

-1.8 V vs. SCE -1.0 V vs. SCE

1000 1250 1500 1750 2000 2250 2500

Wavenumber (cm-1)

4.5 Benefits of natural chemicals Every natural chemical has beneficial effects on human if used in correct proportion and state. This principle has been used in medical science and practiced in every civilization. Even today, it is well known that heavy metals and other otherwise toxic chemicals are used in western medicine because of their actions on human body. Following is a discussion on several metals that are frequently used in western medicine. This discussion is useful to understand that natural chemicals should be considered as catalysts as well as a valued by-products from petroleum resources. Of the chemicals used, Aluminum has the highest charge density. In the past, it was generally accepted that aluminum was strictly excluded from “biological design.” This was due, in part, to its high aqueous insolubility at physiological pH, its slow exchange rate in biological systems, its unchanging 3 1 valence, unusually high charge density, reactivity, and incompatibility with other biologically active systems (Fig. 4.32). There are numerous instances, wherein aluminum salts and hydroxides have been shown to aggregate peptides and proteins in biological systems. Interestingly, there appears to be a strong evolutionary pressure for specific amino acid residues to be selected for incorporation into peptides and proteins that reduces their potential for self-aggregation, and precipitation,

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FIGURE 4.32 Aluminum, a densely charged metallocation “in a class by itself.” Source: From Lukiw (2010).

from aqueous solutions. Despite such evolutionary selection, aluminum efficiently aggregates several different classes of organic molecules in solution, such as amyloid peptides, nonamyloid components, cell cyto-structural neurofilaments, milk casein phosphoproteins, blood coagulation glycoproteins, and small, irregularly shaped anuclear cells also known as thromobocytes (blood platelets). Cadmium is a trace element and transitional metal that is not believed to play a role in higher biological systems or in human nutrition. Cadmium deficiency has not been convincingly shown in humans. Cadmium is toxic in moderate doses and is a potent antagonist of several essential minerals including calcium, iron, copper, and zinc. Cadmium is used in the manufacture of batteries, electrical conductors, and metal plating. Cadmium is also a byproduct of the mining and processing of iron, nickel and other metals and can be toxic to welders and industrial workers, producing a syndrome due to inhalation of excessive amounts known as cadmium fume fever. Environmental exposure to excess cadmium has been reported due to contamination of the water supply from mining or manufacturing with subsequent concentrations of cadmium in agricultural products such as rice, resulting in outbreaks of cadmium poisoning. A disease marked by bone fractures (itai-itai or “ouch-ouch” disease) arose after World War II in a rural area of Japan and was later linked to cadmium contamination of water used to irrigate rice fields. Itai-itai is characterized by renal tubular abnormalities and calcium and phosphate wasting resulting in osteomalacia. Chronic cadmium exposure has been linked to pulmonary fibrosis, chronic renal

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injury, and an increased risk of cancer. Cadmium has not been linked specifically to clinically apparent liver injury in humans although it, like many metals, is toxic to hepatocytes in vitro and causes acute liver injury in experimental animals. Autopsy material from patients with itai-itai disease demonstrates slight increase in fibrosis and steatosis, but the clinical manifestations appear minimal despite high levels of cadmium in liver tissue. The relative lack of hepatic injury with chronic cadmium exposure may relate to potent metallothionein induction in the liver by the trace metal. Cadmium in small quantities is included in many homeopathic medications and in several over-the-counter dietary supplements used to increase vitality and wellness. Chromium is an essential trace element that plays an important role in carbohydrate and lipid metabolism. Chromium deficiency has been linked to insulin resistance and diabetes, and oral supplementation with trivalent chromium has been found to improve insulin sensitivity and glucose tolerance. Claims have been made that chromium also benefits muscle building. As a consequence, chromium is a frequent component of vitamin, mineral, and general nutritional supplements. Trivalent chromium is not well absorbed as simple salts, and complexes of chromium have better bioavailability. Chromium is available in multiple oral formulations (picolinate, dinicocysteinate, complexed with nicotinic acid, and in brewer’s yeast), in tablets and capsules in concentrations of 150 to 1000 μg, and as chromic chloride in a liquid solution (4 μg/mL) for use in parenteral nutrition. In concentrations found in foods and in doses used clinically, chromium has been reported to be safe and without appreciable toxicity. Nevertheless, there have been at least two publications describing renal injury from ingestion of moderately high doses of chromium picolinate for 1 and 4 months, one of which was accompanied by transient liver injury with features of acute hepatic necrosis. High doses of chromium, and particularly hexavalent chromium (6 1 ), can be toxic. Hexavalent chromium is an industrially important metal used in stainless steel and other alloys and is a potent oxidizing agent with known toxicity to industrial workers. Acute, high-dose ingestion of chromium (both trivalent and hexavalent) can cause severe, immediate multiorgan (including liver) damage and death. Lower dose chronic occupational exposure is associated with skin and local tissue injury and may be carcinogenic. Fluoride is a trace element that is concentrated in mineralized tissues such as bone and tooth enamel. Epidemiologic surveys demonstrated a close correlation of fluoride concentrations in water with rates of dental caries, and water fluoridation began as a public health measure in the United States in the mid-1940s. Fluoride has also been shown to have a role in normal hematopoiesis, bone formation and osteoporosis, and fertility and growth. Chronic excessive fluoride intake can be associated with brown mottled teeth and skeletal abnormalities. Acute fluoride toxicity is marked by nausea, vomiting, diarrhea, abdominal pain, excess salivation and lacrimation, heart and lung abnormalities, weakness, neuropathy, convulsions, paralysis, and coma. There have been no reports of acute or chronic liver injury attributed to fluoride toxicity. Iodine is an essential constituent of thyroid hormones and is essential for normal growth and development. Iodine deficiency causes goiter and hypothyroidism in children and adults, and cretinism if present during fetal development. Iodine deficiency is the most common cause of preventable mental defects in the world today. Cretinism and goiter are completely preventable by iodine supplementation. Iodine toxicity is rare, but high

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dietary intake may be responsible for iodine-induced hyperthyroidism. Iodine intake has not been linked to liver injury. Lead is a heavy metal that has major health implications. Even low levels of lead exposure have been associated with harmful effects on health, the major sources in the environment being paint and gasoline. In recent years, lead exposure has been decreased by regulatory actions in removing lead from paint and gasoline and limitation of occupational lead exposure. Lead has no medical uses. Lead toxicity is marked by neurotoxicity, neurodevelopmental defects, gastrointestinal, kidney, and bone marrow toxicity. There does not appear to be major liver toxicity from environmental lead exposure. Manganese is a trace element that exists in many metal-enzyme complexes and metalloenzymes, either as a bivalent (Mn21) or trivalent (Mn31) ion. Manganese functions in enzyme activation and is present in superoxide reductases, ligases, hydrolases, kinases, transferases, and decarboxylases. Manganese deficiency has been reported in animals and possibly in man, with signs of weight loss, nausea and vomiting, dermatitis, impaired growth, and skeletal and hair abnormalities. There are generally adequate amounts of manganese in routine diets and deficiency states are very rare, if they exist at all. Manganese is relatively nontoxic, but excessive exposures accompanied by toxicity have been described in miners and metal workers. Acute toxicity is marked by severe psychiatric symptoms, irritability, anxiety, hallucinations, and violent acts. Chronic toxicity can lead to chronic neurologic disorders with headaches, muscle weakness, speech disturbance, and extrapyramidal signs. Liver toxicity has not been described. Mercury is a nonessential trace metal that is a well-known toxin, second only to lead as a cause of heavy metal poisoning. Mercury is used in many areas of manufacturing and is present in dental and medical equipment. Because of the toxicity of acute and chronic exposure to metallic mercury, this metal is now used less and less in industry and attempts are made to remove it from household and medical equipment and appliances. Mercury is also present in fertilizers and pesticides. Mercury used to be used medically, for instance in the therapy of syphilis; however, with safer and more effective therapies, mercury has been abandoned as a primary therapy. Chronic methyl mercury exposure is associated with symptoms of weakness and fatigue, headaches, lower back pain, ataxia, slurred speech, tremor, somnolence, and mental disturbances, including hallucinations and acute psychosis. Any involvement of the liver is overshadowed by the central nervous system toxicity. Molybdenum is a transition element and is present in several human enzymes, such as xanthine and sulfite oxidases, and in enzyme cofactors in oxidative reduction reactions. Molybdenum is found in many foods and deficiencies are rare. Molybdenum deficiency has been described in animals and rare cases have been reported in patients on total parenteral nutrition, clinical signs being mental disturbances and coma accompanied by hypouricemia and hypermethioninemia. Molybdenum is relatively nontoxic, although high levels may be a cause of high uric acid levels and an increased incidence of gout. Liver toxicity from molybdenum has not been described. Nickel is a heavy metal and trace element that is active in many chemical reactions, but is not clearly an essential element in humans. No metabolic or biochemical function for nickel has been identified in higher animals, but it is found in many tissues and actively interacts with other metals, vitamins, and proteins. Nevertheless, nickel deficiency states

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have not been identified in humans. Nickel can be toxic at high levels, but is unlikely to occur from dietary sources. Nickel can also cause allergic reactions, particularly dermatologic ones. There is no evidence that nickel causes liver toxicity. Selenium is present in biological systems in amino acids, such as selenocysteine and selenomethionine, usually as a part of proteins, which are referred to as selenoproteins. While selenium is present in many important enzyme systems, deficiency of selenium is rare. Keshan disease, an endemic cardiomyopathy affecting children and young women in parts of China, has been linked to selenium deficiency, although other nutritional deficiencies or local factors may also may a role. Excess selenium exposure can cause cirrhosis in laboratory animals, but toxicity in humans has been linked largely to skin, hair, and nail changes. An outbreak of possible selenium toxicity due to a nutritional supplement was marked by nausea, diarrhea, irritability, fatigue, neuropathy, hair loss, and nail changes, without liver test abnormalities. Silicon is a trace element that resembles carbon and can form silicon
carbon as well as silicon
oxygen, silicon
hydrogen, and silicon
nitrogen bonds. The distribution of silicon in bodily tissues suggests that it may be important in cartilage and bone. Silicon is nontoxic when taken orally and has been used in antacids (magnesium trisilicate) for over 50 years without evidence of toxicity. Tin is a trace element and metal that is widely found in nature and is detectable in many tissues and nutrients. Tin deficiency has been described in rats but has not been clearly shown to exist in humans, and its role in normal human metabolism is not clear. Currently, tin is not considered an essential element, although it is sometimes included in homeopathic medications and in over-the-counter dietary supplements. Tin is relatively nontoxic, but can alter the metabolism of other trace elements such as zinc and copper. Minor amounts of tin ingestion can cause gastrointestinal distress with nausea, cramps, vomiting, and diarrhea, but the reaction is generally mild-to-moderate in severity and self-limited in course. Tin poisoning as might occur with industrial exposure or accidental ingestion, on the other hand, can cause visual effects, stupor, and neurologic abnormalities. Vanadium is a trace element that exists in multiple oxidation states and forms complexes with proteins. Vanadium has not been shown to be an essential element and, indeed, is absorbed poorly. No deficiency state of vanadium has been demonstrated in humans. High doses of vanadium are toxic to animals and can cause neurologic, hematologic, renal, and hepatic toxicity. Feeding of high doses to humans causes gastrointestinal upset, but vanadium has not been linked to hepatotoxicity due to dietary intake or environmental exposures in humans.

4.6 Science of nanoscale Unlike commonly held belief, the use of nanoparticles has a long history. Nanoparticles were used by artisans as far back as the 9th century in Mesopotamia for generating a glittering effect on the surface of pots. This was denoted as “luster art,” which refers to a metallic film applied to the transparent surface of a glazing, consisting of Cu or Ag nanoparticles. In this way, beautiful iridescent reflections of different colors (in particular gold and ruby-red) are obtained (Padeletti, and Fermo, 2003). During the Islamic golden era

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(8th
13th centuries), this technology was taken to another high as nongold decoration materials are sought after in Islamic culture (Khan and Islam, 2016). Michael Faraday was the first one among New scientists to study the size-dependent optical properties of gold and silver colloids or nanoparticles (Wilcoxon, 2009). However, only recently renewed interest in nanoparticles has emerged, mainly because of the possibility of revolutionizing novel materials production (Zaman et al., 2012; Islam and Mokhatab, 2018; Morris, 2011). In the modern era, and in the last decade in particular, insights and discoveries in the field of nanostructures are booming (Morris, 2011). The combination of reduced size and special properties make nanoscience intriguing. Nearly 3 decades of worldwide revolutionary developments in nanoscience, combining physics, chemistry, material science, theory, and even biosciences, have brought us to another level of understanding. The public interest and popularization of nanotechnology have made the importance of this science synonymous with the Information Age. With it has come to the “science fiction” version of New Science. New Science has morphed into quantum science, with the promise to fabricate, characterize, and manipulate any natural tendencies of nature into artificial structures, whose features are controlled at the nanometer level. Such properties can be, for instance, strength, electrical and thermal conductivity, optical response, elasticity, or wear resistance. Research is also evolving toward materials that are designed to perform more complex and efficient tasks. Examples include materials that bring about a higher rate of decomposition of pollutants, a selective and sensitive response toward a given biomolecule, an improved conversion of light into current, or more efficient energy storage. For such and more complex tasks to be realized, novel materials have to be based on several components whose spatial organization is engineered at the molecular level. The problem is, nanotechnology has encouraged development of technologies that are excellent in producing results that conform to the market demand rather than addressing the problem of original unsustainability of a technique. For instance, the microelectronics industry is fabricating integrated circuits and storage media whose basic units are approaching the size of few tens of nanometers. For computers, “smaller” means higher computational power at lower cost and with higher portability. Unfortunately, the advent of new methods for the controlled production of nanoscale materials has provided new tools that can be adapted for this purpose, all maximizing speed of producing results for the smallest amount of investment costs. New terms such as nanotubes, nanowires, and quantum dots are now common jargon of scientific publications. These objects are among the smallest man-made units that display physical and chemical properties which make them promising candidates as fundamental building blocks for novel transistors. The advantages envisaged here are higher device versatility, faster switching speed, lower power dissipation, and the possibility of packing many more transistors on a single chip. However, this race toward higher performance assumes that original versions are actually accurate and sustainable. In reality, the opposite is the truth, as outlined by Islam et al. (2016). This trend in nanotechnology has virtually guaranteed new technologies are more unsustainable than the older ones. As intervention takes place in locations involving smaller “particles,” the departure from natural order takes place at a more fundamental level. Similarly, the pharmaceutical and biomedical industries are rushing to synthesize large supramolecular assemblies and artificial devices that mimicking the superficial aspects of the complex mechanisms of nature or that can be potentially used for more efficient diagnoses and better cures for diseases. Examples in this direction are nanocapsules such as

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liposomes, embodying drugs that can be selectively released in living organs, or bioconjugate assemblies of biomolecules and magnetic (or fluorescent) nanoparticles that may provide faster and more selective analysis of biotissues. The entire exercise hovers around developing more and more unnatural means to study nature. Of course, whenever a contradiction arises, it is countered with dogmatic fervor and yet another new term is coined to explain away paradoxical “science” (Islam et al., 2015). ISO’s working definition of nanotechnology is as follows: the application of scientific knowledge to the control and use of matter at the nanoscale, where size related phenomena and processes may occur (ISO, n.d.). The type of properties that could not be perceived in the past, such as ultralightweight, superstrong, rust-proof materials, could be developed based on nanoscale technology. Laboratory measurements have made it clear that one can take a multiwall CNT and get what amounts to 100-gigapascal tensile strength, which is 20 times stronger than the strongest carbon fiber made today. The intrigue in this technology is, unlike common perception, there needs to be no genetic-engineering like manipulation involved. CNTs are essentially continuous Buckyballs, allotropes of carbon with a cylindrical nanostructure. Nanotubes can be single- or multiple-walled, and can be constructed with a length-todiameter ratio of up to 132 million-to-1, significantly larger than any other material. It is well known that the carbon-to-carbon bond is the strongest of all possible elemental bonds, with nanotubes exhibiting tensile strengths 100 times that of steel. In addition to their extraordinary strength, nanotubes have novel electrical and thermal conductive properties that give them potential value in a range of applications but that are extremely difficult to characterize with new science. This difficulty stems from the fact that the atomic theory has been hopeless in addressing these problems because none of the conventional theory applies in nanoscale. Nanotechnology deals with the small construction at the atomic and molecular levels about the length occupied by five to ten atoms stacked together or equivalently, 1/50000th the diameter of human hair. At least one characteristic length of the constructional and functional unit of nanostructure should be in nanometer range. At this dimension, amazing manifestation of the nanomaterials
such as 10 times lighter but 250 times stronger than steel—creates the potential for a new horizon in different areas of science and technology. The petroleum industry is not an exception. This industry too needs technological breakthrough to meet the tremendous increase in demand. At present, the fascination for understanding nanoscale phenomenon is entirely driven by economics. The economic and societal promise of nanotechnology has led to involvement and investments by governments and companies around the world. The type of involvement US government had in terms of internet technology that has onset the Information age is repeated in nanotechnology. As early as 2000, the United States became the first nation to establish a formal, national initiative to advance nanoscale science, engineering, and technology—the National Nanotechnology Initiative. This initiative has generated significant domestic and international investment opportunities in nanoscale research. Fig. 4.33 shows how various organizations predicted revenues from nanotechnology activities. Some pessimistic sides of these predictions vastly ignore the applications in the oil and gas industry. Magnetic Sensing, although known throughout history, has taken a new meaning under the auspices of nanotechnology revolution. Today, such particles can be manufactured. These nanoparticles that can be manipulated using magnetic field gradients. Such particles commonly consist of magnetic elements such as iron, nickel and cobalt and their chemical

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FIGURE 4.33 Estimates of revenues from nanotechnology applications in the United States. Source: Updated from Tiague (2007).

compounds. They might involve particle size ranging from 0.5 to 500 nm. While nanoparticles are smaller than 1 μm in diameter (typically 5
500 nm), the larger microbeads are 0.5
500 μm in diameter. The magnetic nanoparticles are attractive for many applications, ranging chemical engineering to medicine. Specific applications are in developing catalysts (Lu et al., 2004; Tadic et al., 2014), biomedicine (Gupta and Gupta, 2005), magnetically activated photonic crystals (He et al., 2012), microfluidics (Kavre et al., 2014), magnetic resonance imaging (MRI) (Mornet et al., 2006), magnetic particle imaging (Gleich and Weizenecker, 2005), data storage (Frey et al., 2009), environmental remediation (Azain Abdul Kadhar et al., 2014), nanofluids (Philip et al., 2006), optical filters (Philip et al., 2003), defect sensor (Mahendran, 2012), and cation sensors (Philip et al., 2013). The physical and chemical properties of magnetic nanoparticles can be greatly affected by slight changes in synthesis method and chemical structure. Only recently, techniques are emerging that would allow one to invoke changes without altering natural properties of matter (Kalia and Averous, 2011). Islam and Mokhatab (2018) recently identified major research thrusts in nanotechnology as follows: 1. Characterization of nanomaterials. 2. Pathway analysis of natural and engineered nanomaterials. 3. Synthesis and manipulation of nanomaterials and the long-term impact on the environment. 4. Modeling of nanoscale phenomena. 5. Novel methods of microscopy and spectroscopy. 6. Natural nanoparticles as nanosensors. 7. Novel methods for describing forces prevalent in nanoscale. 8. Comprehensive modeling of subatomic particles. 9. Novel nanosensors.

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Nanomagnetics. Nanobiotechnology and health impact. Comprehensive theories of nano-optics, nano-photonics. Nanoscaled modeling and simulation. Scaling up of nanoscale phenomena. EOR and Improved Waterflood with nanofluid. New generation of 4D mapping.

The previous line of research has been strictly on the path of developing engineered materials. It has been almost forgotten what the purpose of the research actually was. Picture 4.1 shows how far this obsession with artificial has gone. This picture shows how nanomaterials are being “branded.” If the premise that unnatural cannot be sustained (Khan and Islam, 2012), one must have concern for the long-term impact of the engineered chemicals. This concern has been in the forefront of US strategy. For instance, Michelson (2013) writes: However, upon further review of this particular set of “top 10” priorities, the third entry on the list might seem somewhat out of place. Titled “Small Comfort”—and illustrated with a circular image encompassing a series of hexagonal shapes that, perhaps, are meant to indicate the structure of atoms and molecules—the ensuing description notes that “long touted as the next ‘big thing,’ nanotechnology is already moving from research to market. . .. But safety concerns continue to dog the emerging field” to the extent

PICTURE 4.1 Laboratory name is branded on nanomaterials with focused ion beam.

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that “the next president must decide if the country needs to revise its nano safety strategy to strengthen protections for the public” (Michelson, 2013).

Whereas natural water-borne nanoparticles are ubiquitous, their very small size, ranging from 1 to 100 nm means they are both highly mobile and chemically reactive. Nanoparticles are central in buffering environmental systems, serving the dual role of limiting potentially toxic metal concentrations, while at the same time providing a supply of metals at levels that enables biochemical reactions to take place. Recent analysis of Islam et al. (2015) indicates that natural nanomaterials are both sustainable and necessary for the ecosystem, whereas engineered materials are bound to show negative impact on the environment.

4.7 Zeolite as a refining catalyst Even before the detailed composition of naturally occurring zeolite is known, the natural state of such a powerful agent should confirm that its usage is not harmful to the environment. Similar properties have been identified in limestone as well as in vegetable oils, which can be used as a solvent for removing sulfur compounds. The use of zeolite or similar naturally occurring separation materials would be benign to the environment and would also eliminate the additional cost of cobalt, nickel, and molybdenum processing, bringing in double dividend to the petroleum processing industry. Zeolites can be defined as crystalline, porous aluminosilicates in which the primary building blocks are TO4 tetrahedra having a Si41 or Al31 cation (T atoms) at the center and four oxygen atoms at the corners (Primo and Garcia, 2014). Each corner is shared by two TO4 units forming a tridimensional framework defining cavities, channels, and empty spaces generally denoted as “micropores.” This porosity defined by the rigid crystal lattice is open to the exterior of the solid crystallite allowing the mass transfer from the exterior to the interior of the zeolite particle and the intracrystalline diffusion of molecules smaller than the micropore dimensions. Zeolite has long been known for its very high internal surface area that contributes to water absorption. The microstructure of zeolite is such that it acts like a molecular sieve, providing the site for perfect ion exchange. Zeolites have a porous structure that can accommodate a wide variety of cations, such as Na1, K1, Ca21, Mg21, and others. These positive ions are rather loosely held and can readily be exchanged for others in a contact solution. The advantage of this structure is these chemicals can be released easily thereby activating their role as a catalyst. As these cations are natural, they do not pose any negative impact on the refining process. Some of the more common mineral zeolites are analcime (NaAlSi2O6 H2O), chabazite ((Ca,K2,Na2)2[Al2Si4O12]2 12H2O), clinoptilolite ((Na,K,Ca)2
3Al3(Al,Si)2Si13O36 12H2O), heulandite ((Ca,Na)2
3Al3(Al,Si)2Si13O36 12H2), natrolite (Na2Al2Si3O10 2H2O), phillipsite ((Ca,Na2,K2)3Al6Si10O32 12H2O), and stilbite (NaCa4(Si27Al9)O72 28(H2O)). An example of the mineral formula of a zeolite is Na2Al2Si3O10 2H2O, the formula for natrolite. These cation-exchanged zeolites possess different acidity—a quality that dictates their effectiveness and applicability as a catalyst. The key parameter that controls many properties of the zeolites having a large influence on their catalytic activity is their aluminum content—as measured by the number of aluminum atom for each silica atom.











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Zeolites can be classified depending on the pore size as small, medium, and large pore size zeolites when the openings of the micropores are constituted by rings of eight, ten, or twelve oxygen atoms. Fig. 4.34 summarizes the chemical composition of a zeolite and the properties that derive from it. Due to the different charges of Al31 and Si41, the TO4 tetrahedra can have a net negative charge (AlO4) or can be neutral (SiO4). The consequence of the presence of Al31 in framework positions is the appearance of an equivalent number of negative charges in the framework that require the presence of charge-balancing cations to ensure the electroneutrality of the solid. These charge-balancing cations occupy the micropore space and because they are not grafted into the framework and are bonded to the lattice by Coulombic forces, they can be totally or partially exchanged by different cations. In fact, one of the main applications of zeolites is in detergent formulations as water softener to remove Ca21 ions from hard waters by ion exchange with Na1. These compensating cations can exist naturally or can be introduced during the synthesis of zeolites and can be either inorganic or organic. One particular case that is of considerable importance for the use of zeolites as catalysts in refining is the case in which the charge compensating cation is formally a proton. In this case, zeolites are called “solid acids” and due to the microporosity these internal protons can act as Bro¨nsted centers in heterogeneous catalysis. Although Si41 and Al31 ions have very similar ionic radius and fit nicely in the center of TO4 tetrahedra, the presence of Al31 introduces a relative lattice instability due to the somewhat larger ionic radius of Al31 with respect to Si41, the charge unbalance and low coordination number around Al31. Thus there is a tendency of Al31 to migrate outside the lattice forming octahedrally coordinated Al species that are generally denoted as extra framework aluminum (EFAL). High Al31 content makes the zeolites very prone to develop EFAL, generating Lewis acid sites. The Bro¨nsted acidity of a zeolite is also influenced by the presence of Lewis acidity. This synergy between EFAL and Bro¨nsted acid sites resulting in an increase of the acid strength is similar to that found in liquid acids in which the combination of Bro¨nsted and Lewis acids can render superacids with remarkably enhanced strength (Fig. 4.35).

FIGURE 4.34 Chemical composition of zeolites and possibilities for its control. Key parameters are the nature of charge-balancing cations and the Si/Al ratio.

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FIGURE 4.35 Synergy between Lewis acid sites (AlO1) and Bro¨nsted OH site leading to an increase in acid strength.

Besides the composition, the acidity of the zeolites also depends on their structure. It has been found that for similar chemical composition, the strength of acid sites in medium pore size zeolites is higher than that found in large pore size zeolites (Huang et al., 2008). Acidity is an extremely important property in catalysis by zeolites for refining since many of the processes are proteolytic C
C bond cleavages or involve the generation of carbocations. The most widely accepted mechanism for hydrocarbon cracking involves protonation of single C
C or C
H bonds of alkanes and the generation of carbocations that subsequently undergo b-scission forming a smaller carbocation and an alkene. One point that has been controversial and of wide interest is to determine whether or not the acid sites of zeolites can be considered as superacidic and what is the maximum acid strength that can be achieved in zeolites. However, the most important point in this regard is the fact that if the zeolite is naturally occurring, it will make the subsequent reactions sustainable and if it is synthetic, the opposite would take place. As stated earlier, zeolite microstructure acts as a sieve. One of the main problems in porous solids in which the reaction takes place predominantly inside the pores is intracrystalline diffusion. The pores defined by the framework are open to the external surface allowing the mass transfer from the exterior toward the interior of the particle, provided that the size of the molecule is smaller than the dimensions of the pores. Zeolites are microporous materials (pore size of 2 nm). Zeolites can be classified according to the pore size. In “small pore” zeolites, having apertures defined by 8 oxygen atoms, only small gas molecules can access the interior. In the case of “medium pore” zeolites (10-membered ring apertures), benzene, toluene, and para-substituted aromatics can enter through the pores. The range of molecules that can diffuse in “large pore” zeolites having 12 membered rings is much larger, since the dimensions of these pores are typically around 0.7 nm. Besides pore dimension, the geometry of the pore system is crucial to determine the intracrystalline diffusion coefficient of molecules. Diffusion in monodirectional zeolites, which is typically a synthetic product, having parallel channels, such as mordenite, is generally more difficult than in bi- and tri-directional zeolites. In the case of monodirectional pores, molecules diffusing in the channel have to move one after the other following the same direction and can be easily blocked by a single molecule. In contrast, diffusion in open tridirectional zeolites, such as faujasites X and Y, is easier, since the cavities can be accessed through four independent windows. Furthermore, monodirectional zeolites are prone to becoming deactivated by a small percentage of poisons blocking the entrance of the channels, while bi- and tri-directional zeolites can tolerate a larger percentage of poisons before undergoing deactivation.

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In this process, natural zeolites have a distinct superiority over synthetic ones. In external features, both natural and synthetic zeolitic crystalline aluminosilicates are useful as catalysts and adsorbents. These aluminosilicates have distinct crystal structures which are demonstrated by X-ray diffraction. The crystal structure defines cavities and pores which are characteristic of the different species. The adsorptive and catalytic properties of each crystalline aluminosilicate are determined in part by the dimensions of its pores and cavities. Thus the utility of a particular zeolite in a particular application depends at least partly on its crystal structure. Because of their unique molecular sieving characteristics, as well as their catalytic properties, crystalline aluminosilicates are especially useful in such applications as gas drying and separation and hydrocarbon conversion. Although many different crystalline aluminosilicates and silicates have been disclosed, there is a continuing need for “new” zeolites and silicates with desirable properties for gas separation and drying, hydrocarbon and chemical conversions, and other applications. The tendency in the industry has been to produce synthetic form, custom designed for particular applications. Crystalline aluminosilicates are usually prepared from aqueous reaction mixtures containing alkali or alkaline earth metal oxides, silica, and alumina. On the other hand, “nitrogenous zeolites” have been prepared from reaction mixtures containing an organic templating agent, usually a nitrogen-containing organic cation. By varying the synthesis conditions and the composition of the reaction mixture, different zeolites can be formed using the same templating agent. Use of N,N,N-trimethyl cyclopentylammonium iodide in the preparation of Zeolite SSZ-15 molecular sieve is invented through a series of patents. These patents rely on very toxic processes that retain the external features of Zeolites while replacing naturally occurring chemicals with artificially produced ones. Often other chemicals are blended in so that the resulting zeolite can have specialized qualities. For instance, the use of aluminum oxide, gallium oxide, iron oxide, boron oxide, silicon, germanium, and mixtures thereof has gained widespread applications in the manufacturing industry. Concerning reactivity, the pore size can be responsible for the control of the product distribution. The term “shape selectivity” has been coined to denote those cases using zeolites or other microporous solids as catalysts in which the reason why a product is predominantly formed is exclusively the molecular shape and dimensions. For naturally occurring zeolite, this is not an option and one cannot custom design to fit a particular application. As can be seen from Figure 6.24, when carrying out the reaction inside the medium pore zeolite ZSM-5 in which the pore dimension only allows diffusion of p-xylene, m- or p-xylene formed in the crossings of the channel system cannot diffuse out of the crystals and become entrapped until they rearrange to the p-xylene that is the only one that can go out of the pores (Fig. 4.36).

4.7.1 Gasoline pool The automotive industry has been using the light naphtha fraction of the crude oil marketing it as gasoline (“light straight run” gasoline). The quality of the gasoline is quantitatively measured by the octane number, the higher the octane number, the higher the ability of the gasoline to stand high pressure and temperature. In this scale, the performance of n-heptane and 2,4,4-trimethylpentane has been arbitrarily assigned 0 and 100. In general, the octane number of a pure hydrocarbon increases with the degree of branching, presence of cycles or for aromatic compounds. As the demand for gasoline increased as

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FIGURE 4.36 Schematic of the shape selectivity for the formation of p-xylene in toluene disproportionation.

Isobutane +butenes

Alkylate CH3OR

Gasoline Pool

Reformate

Light straight run

Isomerizaon Hydrocracking FCC unit RESIDES Vacuum gasoil

FIGURE 4.37 Streams contributing to gasoline pools.

well as the need for octane numbers higher than those characteristic of light straight run gasoline (about 70), it was necessary to blend various streams of the refinery in a pool to meet the requirements of gasoline production and quality. Fig. 4.37 presents the composition of a representative gasoline pool indicating the origin of the individual components.

4.7.2 Linear paraffin isomerization One of the components of the gasoline pool is the naphtha fraction. Light straight run naphtha is constituted, mainly, by linear alkanes accompanied by a small percentage of aromatics, and has typically an octane number about 74 or below, insufficient to be added directly to the gasoline pool. This light straight run naphtha should be, therefore, submitted to isomerization, a process that is based on the use of acid zeolites as catalysts. The octane number of linear alkanes decreases as the number of carbons increases, and therefore, these longchain linear compounds present in this fraction (mainly C7 and C8) should be preferentially

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isomerized in the process. At a given temperature the equilibrium distribution among isomers limits the extent in which linear paraffins are converted into branched isomers. The general tendency is that isomerization is disfavored as the temperature increases in the range from 0 C to 600 C. Therefore from the thermodynamic point of view, it is convenient to work at the lowest possible temperature. Thus the role of the catalyst is to increase the reaction rate allowing the reaction to reach equilibrium at the lowest possible temperature. Isomerization of linear alkanes requires acidity combined with dehydrogenation/hydrogenation capability. In this particular application, both the natural state of zeolite as well as the form of energy related to the heating will dictate if the products will be environmentally benign or not.

4.7.3 Isobutane
butene alkylation About 12% of the blend in the gasoline pool may come from butene alkylation. The acid catalyzed mechanism for isobutane
butene alkylation is shown in Fig. 4.38. This stream has a high octane number, ideally 100, and is much valued since it does not contribute to the gasoline sulfur content, because isobutane and butene are free from this contaminant. Classical alkylation processes are based on the use of homogeneous liquid acids and particularly HF and H2SO4. From the catalytic point of view, the two main relevant properties of the liquid acids are their decay and isobutane solubility in the acid phase. Isobutane solubility is much higher in HF than in H2SO4. This allows reaching a higher concentration of isoalkane favoring hydrogen transfer steps to carbenium ions, reducing the carbocation FIGURE 4.38 Simplified mechanism for isobutane
butene alkylation and competing unwanted processes. t-C4 1 , tert-butyl cation; 2-C4Q, isobutene; TMP, trimethylpentanes; sec-C4 1 , sec-butyl cation; DMH, dimethylhexanes; HT, hydride transfer.

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lifetime, and minimizing secondary reactions. These advantages exhibited by HF allow shorter contact times and operation at higher temperatures where the reaction rate is higher. In contrast, although the acid strength of H2SO4 is much higher, this acid presents also high viscosity and density unfavorable for the mixing with hydrocarbons, complicating significantly reactor design to ensure sufficient contact between the two phases. An additional problem with the use of H2SO4 is that the amount of acid lost in the products is much higher, requiring larger catalyst makeup. Makeup and regeneration are about 30% of the total operation cost in the case of H2SO4, while they represent only 5% for HF. The main problem of HF is, however, its large negative environmental impact that requires strict safety measures due to the high risk of accidental leakages and the fact that HF aerosol can stand as highly corrosive, persistent clouds over long periods of time. For this reason, there is no clear advantage in the use of HF as opposed to H2SO4 as an alkylation catalyst. One alternative to the use of liquid acids is the use of solid acids. Amorphous silica
alumina has been used as solid catalyst, but zeolites have the advantage of a higher activity, higher durability, and lower deactivation. The activity of zeolites depends on the Si/Al ratio and on the crystal structure.

4.7.4 Fluid catalytic cracking Fluid catalytic cracking (FCC) provides a surplus of high octane number gasoline by converting vacuum distillates, particularly vacuum gasoil, into gasoline. From the chemical point of view, several molecular transformations are concurrently taking place during FCC, including shortening of linear long alkanes, isomerization of linear into branched alkanes, and dehydrogenation of cyclic olefins into aromatic naphthenes. Fig. 4.39 shows the schematic of the process involved.

FIGURE 4.39 Elementary processes taking place in fluid catalytic cracking.

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Fig. 4.39 shows the major reactions that take place during FCC (from Islam et al., 2010) (Fig. 4.40). The FCC catalyst contains an active component (10
50 wt.%) dispersed on a solid matrix (between 50% and 90% of the total) providing physical and mechanical resistance and embedding the active component, and some additives that increase the tolerance of the catalyst against deactivation by poisoning (Fig. 4.41). The active phase is generally a large pore zeolite, often accompanied with rare earth metals. In general, an increase in the percentage of rare earth metals leads in an increase in feed conversion accompanied by an undesirable decrease in the octane number of the resulting gasoline. Also, framework dealumination results in an increase in the activity of the zeolite, particularly considering that zeolite Y has high Al content. Steam treatment is a convenient procedure to reduce framework Al, and that also increases mesoporosity of the crystallites due to the partial damage of the zeolite particles leading to the creation of mesopores above 6 nm, highly beneficial for the activity and stability of the zeolite by favoring intracrystalline diffusion of substrates and products reducing poisoning derived from long contact times of substrates and products with the acid sites. In addition, the composition (Si/Al ratio) is an important parameter that controls the activity and selectivity, which in general increase as the average crystal size decreases. Fig. 4.42 shows the parameters that control the activity of zeolites as cracking catalysts. One problem of FCC catalysts is the tolerance to the presence of metals and particularly Ni and V. These and other metals can be present in high molecular weight organic compounds present in the FCC feed. Deposition of Ni on the catalyst favors the generation of coke on the catalyst due to its dehydrogenating capability. To minimize the influence of

FIGURE 4.40

Elementary steps assumed to take place in catalytic cracking on zeolites.

FIGURE 4.41

Acid zeolite

Additives

Binder

 10-50 wt%  Avoid negative  50-90 wt%  Responsible for  Large pore of metals  Responsible for mechanical strength  effect Aimed at increasing  activity  Typically Al O or SiO octane number 2 3

2

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FIGURE 4.42 Main parameters that influence the catalytic activity of zeolites in fluid catalytic cracking formulations.

Parameters controlling catalytic activity of zeolites

Si/AI ratio

Steaming

Population and strength of acid sites

Creating EFAL controlling selectivity

257

Crystallite size Controlling diffusion Increasing external surface area

Ni, FCC catalysts contain additives, such as Sb that acts as a poison of Ni by forming Ni
Sb alloys, inactive to promote dehydrogenation. These catalysts can render the entire fluid stream toxic, thereby making the resulting oxides unacceptable by the ecosystem. Also, the effect of Ni can be neutralized by alumina present abundantly in the catalyst matrix by forming Ni aluminates that have much lower dehydrogenation activity. V also has some activity for hydrogen evolution and coke formation during the FCC process. However, the main problem caused by V is the formation of strong acids during regeneration of FCC catalyst that produce deterioration of the zeolite crystal structure reducing its service life. To minimize this effect of V, the use of more robust zeolites, generally those having low Na and Al content, as well as the presence of vanadium trapping compounds in the additives, generally basic solids such as CaO, Al2O3, or MgO are recommended. However, this should not lead to the use of synthetic zeolite. The fraction of additives of FCC catalysts may also contain some components to effect NOx decomposition. Nitrogen is present in the FCC feed and about 50% of the N in the FCC feed becomes deposited on the catalyst as coke. During FCC catalyst regeneration by combustion of coke, part of the nitrogen evolves as N2, but the other part forms NOx that have to be decomposed to avoid their emission to the atmosphere. Another problem of the FCC stream is that this fraction contributes to a large extent to the total sulfur content present in gasoline and diesel. About 90% of the total sulfur content of the gasoline is due to the FCC contribution, coming mainly from the heaviest fractions. Typical sulfur-containing compounds in FCC gasoline are mercaptans, dialkylsulfides, thiophenes, alkylthiophenes, and benzothiophene, while heavier aromatic sulfur components particularly dibenzothiophene and its alkyl derivatives are present in diesel. Legal regulations are constantly reducing the sulfur content of fuels and achievement of such low S contents currently requires the combination of several technologies. The overall strategy to control the sulfur content in fuels includes the selection of crude oil and adequate fractionation of FCC gasoline to reduce the sulfur in the feed but also posttreatment of FCC gasoline and diesel. Among FCC desulfuration posttreatments, one of the emerging technologies is the selective liquid-phase oxidation of thiophene and aromatic S compounds under mild conditions, using tert-butyl hydroperoxide or H2O2 as the oxidizing reagent. In this way, the sulfur atom becomes oxidized to sulfoxide or sulfone, increasing considerably water

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solubility and boiling point of the sulfur compounds, allowing their easier separation from the fuel, as shown in Fig. 4.43. This catalytic oxidative desulfuration could lead to fuels with sulfur content below 10 ppm that will be the legal specification in the very near future. One promising catalyst for oxidative desulfuration is Beta zeolite containing Ti atoms, which can exist in natural state in certain zeolites.

4.7.5 Reforming One of the most important processes in refining is the reforming of the heavy naphtha fraction into mixtures in which aromatic compounds and particularly benzene, toluene and xylenes are the predominant compounds. Chemically, the reforming corresponds to the chemical transformation of saturated acyclic and cyclic hydrocarbons into aromatic compounds by dehydrogenation without reducing substantially the number of carbons of the products with respect to the substrates. Fig. 4.44 presents the elementary transformations that take place in reforming. These transformations include cyclization of acyclic compounds, isomerization of cyclic compounds into cyclohexene and dehydrogenation and aromatization. The main purpose of reforming is to obtain aromatics because these compounds exhibit octane numbers over 100 and following their addition into the gasoline pool they lead to a notable increase in the octane number of the resulting blend. A minor percentage of reformate is used by the chemical industry to obtain pure benzene, toluene, and xylenes and from them bulk chemicals, monomers, and commodities, but this use represents around 10% of the total reforming capacity. Two processes related to the industrial use of reformate are toluene disproportionation and xylene isomerization. The composition of gasoline and transportation fuels have been evolving to comply with legal regulations, and one common trend in developed countries, together with providing gasoline with high octane number and the use of the three way catalysts to avoid

FIGURE 4.43

Desulfuration based on catalytic oxidation of sulfur compounds present in heavy gasoil fractions.

FIGURE 4.44 Elementary reactions occurring simultaneously in the reforming of naphtha.

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FIGURE 4.45 Coprocessing of benzene in naphtha isomerization.

the presence of unburned hydrocarbons in the flue emissions, has been to limit and reduce the percentage of benzene in gasoline. The regulations have targeted crude oil instead of targeting artificial chemicals that are used during the refining process. Among all the aromatic compounds, it is considered that benzene is the most toxic one and has a well proven carcinogenic effect. The source of this toxicity, however, is not aromatic compound itself, but rather the artificial heavy metal components that are used (Islam et al., 2015). Consequently, the tendency in the refinery to reduce the percentage of benzene in reformate by adjusting the operation conditions has missed the mark by targeting benzene from reformate to reprocess this chemical mainly with linear alkenes in the isomerization process. Fig. 4.45 illustrates the use of reformate and the connection between reformate and linear isomerization of alkanes. Since according to the chemical transformation dehydrogenation with hydrogen evolution is the major individual process taking place in the reforming, acidity is not a requirement for the catalyst, which, in contrast, should have noble metals with high hydrogenation/dehydrogenation activity as the main active component. Thus most of the commercial reforming catalysts are based on Pt supported on large surface area solids such as nonacidic zeolites or metal oxides. As we will see in later sections, this Pt is a major source of carcinogenicity of the petroleum products.

4.7.6 Hydrocracking One constant feature in refining is the need to convert efficiently less valuable, heavier fractions into mixtures of hydrocarbons of lesser number of carbons for their consumption as transportation fuels. For the conversion of heavier into lighter fractions, one of the processes that is performed on a large scale is the hydrocracking of heavy gasoil, vacuum gasoil and gasoil from coke into lighter compounds. To carry out this process hydrogen is required to minimize the formation of coke and carbonaceous residues on the catalyst and for this reason is termed “hydrocracking.” Several elementary chemical transformations take place in the hydrocracking process, which are similar to those that have been already commented for the cracking. These classes of individual reactions include shortening of the chain length of the paraffins in the feed, isomerization of the linear into branched alkanes, ring closure and hydrogenation/dehydrogenation of the C
C bond (Fig. 4.46). There are two main general types of hydrocracking processes although each of them can be subjected to modifications depending on the needs of each refinery. One of these types is the single-stage hydrocracking in which the fractionating unit is located after the hydrocracker (Fig. 4.47).

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FIGURE 4.46 Elementary steps occurring simultaneously during hydrocracking.

Shorter alkanes + olefins

Alkanes

Isoalkanes + branched Hydrocracking alkanes

n-Alkanes Alkanes

Olefins + H2

Alkanes

Cycloalkanes + H2

Cycloalkanes

Aromatics + H2

Makeup hydrogen Recycle hydrogen

Offgas

Recycle hydrogen

cw

Condenser Recycle Hydrogen Compressor

Catalyst

Offgas

Catalyst

Catalyst

Gas

Heater cw Hydrocracker feed

Rich amine

High Pressure Separators

Condenser

Gas

Amine

Wash Water

Heat Exchanger

cw Jet fuel cw Diesel fuel

Reactor feed

cw

Condenser Gas

c w Cooling water Separator mesh screens

Coolers or condensers

Liquid

Hydrocracker feedstock

Pump

Amine scrubber packing

Pressure Letdown Valve

Pump

FIGURE 4.47

Heavy naphtha

Heater

Low Pressure Separator Sour water

Sour water Light c w naphtha

Pump

Fractionator

Lean amine

Catalyst

Fractionator feed

Amine Scrubber

Reflux

Reactor feed

Catalyst

Recycle hydrogen

Reactor feed

Catalyst

Reflux Drum

Second Stage Reactor

Gas Gas

Recycle hydrogen

First Stage Reactor Recycle hydrogen

345 – 425 °C 80 – 200 bar

Recycle hydrogen

260 – 480 °C 35 – 200 bar

Gas

Makeup hydrogen

Heat exchangers

Heater

Diagram of a single-stage (top) and a two-stage (bottom) hydrocracking process.

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In this type, it can be more than one hydrocracker in series and it could be also recycling or not of the unconverted feed. In the other case, the process is known as once-through, singlestage hydrocracking. The two-stage hydrocracking is characterized by having the main fractionating unit located between two hydrocrackers (Fig. 6.35). Generally the first reactor is used to perform hydrotreatment of the feed to eliminate sulfur, nitrogen, oxygen and metals that could be present in the heavy gasoil fractions. In this first reactor, it could also be a light hydrocracking of the alkanes with formation of a certain percentage of lighter alkanes. Hydrocracking producing effective shortening of the average number of chain carbons takes place predominantly in the second hydrocracker. Hydrocracking requires bifunctional catalysts that are able to promote hydrogenation of olefins and cracking of alkanes. At the metal sites of the catalyst dehydrogenation of the n-paraffin gives rise to the formation of n-olefins that subsequently are protonated by the acid sites to form secondary carbenium ions that undergo spontaneous rearrangement to more stable tertiary carbenium ions. These tertiary carbenium ions can form cracked products through b-scission at the carbocation center or can give rise to an isoolefin that upon hydrogenation will form finally isomerized alkanes. Conventional catalysts for hydrocracking contain a metal that has as the capability to perform hydrogenation/dehydrogenation of unsaturated/saturated hydrocarbons. This metal component can be noble metals such as Pt, Pd or their alloys or can be even metal sulfides such as combinations of Ni, Mo, Ni
W, and Co
Mo. Each of these metals is highly carcinogenic, when refined using conventional techniques. The hydrogenating capability is the highest for Pt and noble metals and is lower for metal sulfides that require higher percentages and higher temperatures in order to exhibit the desired activity, but are less prone to deactivation by sulfur. The order of hydrogenating performance of sulfides is Ni/W 4 Ni/Mo 4 Co/Mo. This metallic component is supported on an acid solid such as amorphous silica
alumina or preferably zeolites. The acid strength of zeolites is higher than that of amorphous silica
alumina and, for this reason, zeolites require lower temperature to act as hydrocracking catalysts, typically, between 300 C and 330 C. In contrast, amorphous silica
aluminas operate at temperatures between 340 C and 390 C. This feature of zeolite is appealing from both economic and environmental perspectives, considering the fact that extra heating with conventional technique also adds to the accumulation of artificial chemicals in the final product. In addition, zeolites also exhibit a lower tendency to deactivate. Generally, amorphous silica
aluminas undergo a quick deactivation at short time on stream leaving a residual acidity that then decreases in activity more gradually for longer times on stream. Concerning the performance of zeolites in hydrocracking, it has been found that high acid strength leads to an increase in the percentage of naphtha formation in hydrocracking at the expense of middle distillates. Increasing the catalyst zeolite content and using strong acid zeolites increases feed conversion and naphtha selectivity. One problem of zeolites as catalysts is the impeded diffusion of large molecules through the internal pores. It has been found that the catalytic activity of Ni-containing Y zeolite decreases drastically along the alkane chain length, a parameter that correlates with the boiling point of the gasoil. If this Ni is made available from a natural source, for example, ore, the sustainability of the process is assured. In contrast, amorphous silica
aluminas lacking porosity exhibit higher activity as the boiling point of the feed increases. This increase of feed conversion with the average chain length of the paraffin is a reflection of the intrinsic higher reactivity of long alkanes toward cracking and should also be observed for zeolites. In order to increase the activity of zeolites

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for high boiling point gasoil fractions, it is necessary to increase accessibility of the reactants to the acid sites. One way to enhance the population of accessible sites is to increase the zeolite external surface area. This increase of the external area can be achieved by reducing the average particle size of the zeolite crystallites from the micro to the nanometer length. This particular requirement has been exploited in order to custom design synthetic zeolites. However, synthetic zeolites are necessarily toxic to the environment and thereby pollute the petroleum products, generating oxidants that are no longer absorbed by the ecosystem. One example of how the dimensions and geometry of the pore system can control the product distribution that has considerable implications in refining is the cracking of heavy gas oil to gasoline with minimum amounts of gases using a bidirectional zeolite ITQ-36 zeolite. In this case, there are two intersecting channels with different dimensions. Gas oil molecules can diffuse through the larger channels accessing the acid sites, but not through the smaller channels. In the acid sites, gas oil molecules undergo cracking forming smaller molecules in the range of the gasoline fraction that diffuse away preferentially through the smaller channels without undergoing undesirable consecutive cracking. Fig. 4.48 illustrates the process. An alternative to the use of microporous zeolites for hydrocracking of long-chain, highboiling point hydrocarbons is the use of acidic mesoporous aluminosilicates. The synthesis in the 80s of MCM-41 and related mesoporous silicas by Mobil researchers constituted a breakthrough in materials science, since these porous materials overcome the pore size limitation found for conventional large pore zeolites below 1 nm and constitute a logical expansion of porous aluminosilicates into the mesopore range. Each of these technologies, however, introduce yet another set of toxic material to the petroleum products. For instance, Ni
Mo support is common. It is true that if the time spent by a hydrocarbon inside the micropores of a zeolite increases, then the probability to reduce the size of this hydrocarbon to C1
C4 products by consecutive cracking increases. A careful selection of the type of zeolites can make the process more efficient and the need to use synthetic catalysts is eliminated. It appears that the use of large pore zeolites favors the formation of preferred trimethylpentanes and that stronger acidity leads to 2,2,4-trimethylpentane that is the standard isoalkane with an octane number of 100. Large pore acid zeolites are preferred to minimize the loss of activity along the time on stream. Besides deactivation, it appears that the presence of some coke causing a partial decrease of the catalytic activity also affects the product distribution, reducing the percentage of C5
C7 with respect to C82C91, while dimerization of butenes may become the predominant process versus isobutane alkylation. In isobutane alkylation, as in most of the refining processes using microporous solids, catalyst reactivation is the key issue.

FIGURE 4.48 Molecular traffic of gas oil through the 18 membered ring channels reaching acid sites and diffusion of gasoline through the smaller channels.

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4.8 Restoring science of nature Engineering today is based on denaturing first, rendering unnatural next (Khan and Islam, 2016). Scientifically, denaturing natural object is equivalent to changing natural frequencies into unnatural frequencies. Considered in its most general aspect, the universe comprising all phenomena can be comprehended as comprising two broad categories: the mechanical and the organic. This can also be characterized as tangible and intangible, in which intangible is the source and tangible is the manifestation. As such, many mechanical phenomena can be found within the organic category. Certain aspects of many organically based phenomena can be defined or accounted for within the category that comprises all forms of mechanism. Frequency, and its measurement, often appears to bridge this mechanical-organic divide. Organically based frequencies have an operating range which itself varies, for example, the length of the lunar year. On the one hand, purely mechanical frequencies also have an operating range, and this range can be set or otherwise manipulated up to a point, for example, the resonant frequency at which a bridge structure may collapse in a sustained high wind. On the other hand, although organically based frequencies can be detected and measured, there is usually little or nothing, beyond a very definite window that must be determined by trial and error, that can be done to manipulate such frequencies. Since Galileo’s brilliant and successful deployment of an elaborate water-clock as an organic-frequency device for measuring with some precision the differential rates of descent to earth of freely-falling masses of different weights, all kinds of apparently natural clocks have been deployed to calibrate many things. This includes even universal standards of the metric system, for example, the cesium atom clock at a Paris laboratory used for setting the standard length of the meter. Problems arise when such frequency-based devices are treated as the generator of values for a variable that is treated as being independent in the sense that we take Newton’s fictional time-variable t to be varying “independently” of whatever phenomenon it is supposed to measuring/calibrating/counting. Outside of a tiny instantaneous range, for example, the period in which Δt approaches 0, naturally sourced frequencies cannot be assumed to be independent in that way. This is a false assumption whose uncritical acceptance vitiates much of the eventual output of the measuring/calibration effort. Such problem arises the moment one makes the phenomenal assumption that frequency is fixed. That’s the idea behind the unit of “second” for time (solar orbit to cesium radiation frequency). New science fixed the frequency (it is like fixing speed of light), then back calculated time. No wonder, later on, time was made into a function of perception (relativity) thereby making the unique functionality schizophrenic. Not only is it the case that “such a problem arises the moment you make the phenomenal assumption that frequency is fixed.” Even t is assumed to be variable that undergoes changes in value, its frequency is not necessarily fixed, this problem persists if the subtler but still toxic assumption is accepted that the rate at which the variable t changes—Δt—is constant in some “continuous” interval over which the derivative df(t)/dt may be taken. Here is where we uncover the truly toxic power of Newton’s Laws of Motion over conscience-based consciousness. That’s when they invoke “known” function, which itself is aphenomenal. The only function that is valid is with infinite order of periodicity (this is beyond chaotic).

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4.8.1 Redefining force and energy All currently available fundamental definitions in New science emerges from Newton’s laws. As such they are full of contradictions and therefore should be revised before the discussion of natural energy can follow (Islam, 2014). The following discussion highlights the shortcomings of the conventional approach. Force: Conventionally, a force is defined to be an influence which tends to change the motion of an object. The inherent assumption is, this “force” is external to the object. This is a false premise because the entire creation is internal and connected to each other, as presented by recent works of Islam et al. (2010a, 2012) and Khan and Islam (2012). Currently it is believed there are four fundamental forces in the universe: the gravity force, the nuclear weak force, the electromagnetic force, and the nuclear strong force in ascending order of strength. In mechanics, forces are seen as the causes of linear motion, whereas the causes of rotational motion are called torques. The action of forces in causing motion is described by Newton’s Laws under ordinary conditions. Subsequently, forces are inherently vector quantities, requiring vector addition to combine them. This further characterization is yet another tactic to cover up for the false first premise. Khan and Islam (2012, 2016) provide one with a detailed deconstruction of Newton’s laws. With the scientific theory of the previous section, one can redefine force as something that drives the universal movement. It is constant, absolute, and immutable. With this definition, there is no need to further characterize force in the above-mentioned categories. This replaces the notion of gravity in conventional sense. The source of this force is the Absolute light that is omnipresent. This description answers the questions regarding what forces make the entire galactic system move—a question that has perplexed modern scientists (Cowen, 2012). Energy: It is commonly defined as the capacity for doing work. One must have energy to accomplish work—it is like the “currency” for performing work. To do 100 J of work, one must expend 100 J of energy. New science postulates the purest form of energy is light that is comprised of photons. These photons are thought to have zero mass. As stated earlier in this chapter, this assertion disconnects mass from energy but invokes Einstein’s formula, E 5 mc2, which itself is based on Maxwell’s formula that considers energy a collection of solid, spherical, rigid balls (similar to atoms). The assertion of zero mass also invokes infinite speed (a notion that was promoted by Aristotle but discarded by Ibn al-Haytham, some 900 years ago). This obvious gaffe is “remedied” by forcing speed of light, “c” to be constant and maximum attainable speed by any particle. Apart from the fact that a zero mass would not qualify to be called a “particle,” this also poses the obvious spurious solution to the equation, E 5 mc2 and renders it an absurd concept. This mathematical fallacy is “solved” with dogmatic assertion of Quantum physics. As such, the product of 0 times infinity gives a value that is a function of the frequency of the photon. Furthermore, it is asserted that a photon can be converted to a particle and its antiparticle (a process called pair creation), so it does convert energy into mass. All equations, therefore, give an answer but are completely devoid of any physical significance. Similar illogical attributes are assigned to Higgs boson, neutrino, and a number of other particles, some of which have zero mass. In addition, it is asserted that certain particles,

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such as neutrino, can travel through opaque material, albeit with a speed lower than that of light (photons). In order to compensate for the concept of gravitational force that is conventionally nonexistent in zero-mass conditions, it is asserted that the Higgs particle is a carrier of a force. This force mediated by the Higgs boson is considered to be universal as the Higgs boson interacts with all kinds of massive particles, no matter whether they are quarks, leptons, or even massive bosons (the electroweak bosons) (Chang et al., 2014). Only photons and gluons do not interact with the Higgs boson. Neutrinos, the lightest particles with almost zero mass, barely interact with a Higgs boson. This description and assignment of special “power” to certain particles is characteristic of pragmatic approach (Khan and Islam, 2012). In simple terms, they are stop gap tactics for covering up the fundamental flaws in basic premises. Neutrinos are considered to be similar to electrons, with one crucial difference: neutrinos do not carry electric charge. Because neutrinos are electrically neutral, they are not affected by the electromagnetic forces which act on electrons. Neutrinos are affected only by a “weak” subatomic force of much shorter range than electromagnetism, and are therefore able to pass through great distances in matter without being affected by it. If neutrinos have mass, they also interact gravitationally with other massive particles, but gravity is by far the weakest of the four known forces. Such repeated characterization of matter and energy with contradicting traits has been the most prominent feature of New science. The characterization offered by Islam et al. (2012) and Khan and Islam (2012) eliminates such needs. When it comes to “heat energy,” New science is full of gaffes as well. The entire ‘heat engineering is based on Lord Kelvin’s work. Lord Kelvin, whose “laws” are a must for modern day engineering design believed that the earth is progressively moving to worse status and which would eventually lead to the “heat death.” So, if Kelvin were to be correct, we are progressively moving to greater energy crisis and indeed we need to worry about how to fight this “natural” death of our planet. Kelvin also believed flying an airplane was an absurd idea, so absurd that he did not care to be a member of the aeronautical club. Anyone would agree, it is not unreasonable to question this assertion of Lord Kelvin, but the moment one talks about the nature progressively improving, if left alone (by humans, of course), many scientists break out in utter contempt and invoke all kinds of arguments of doctrinal fervor. How do these scientists explain then, if the earth is progressively dying, how it happened that life evolved from the nonbiological materials and eventually very sophisticated creature, called homo sapiens (thinking group) came to exist? Their only argument becomes the one that has worked for all religions, “you have to believe.” All of a sudden, it becomes a matter of faith and all the contradictions that arise from that assertion of Lord Kelvin becomes paradoxes and we mere humans are not supposed to understand them. Today, the internet is filled with claims that Kelvin is actually a god and there is even a society that worships him. This line of argument cannot be scientific (Islam et al., 2010). Modern scientists claim to have moved away from the doctrinal claims of Kelvin. However, no theory has challenged the original premise of Kelvin. Even Nobel laureate winning works (review, for instance, the work of Roy J. Glauber, John L. Hall, and Theodor W. Ha¨nsch, along with their Nobel Prize winning work on light theory), consider Kelvin’s concept of absolute temperature a fact. The problem with such assertion is at no time this can be demonstrated through physical observation. Theoretically, at that point,

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there is zero energy, hence matter would not exist either. A matter is being rendered nonexistent because it does not move—an absurd state. However, instead of realizing this obviously spurious premise, New science offers the following explanation: “If you take away energy from an atom, you do so by lowering the energy level of its electrons, which emits a photon corresponding to the energy gab between the electron bands. Keep doing that until the electron is absorbed by the nucleus, and converts a proton to a neutron. Now you need to extract energy from the nucleus. How are you going to do that? How are you going to shield the resulting neutron from the influence of the rest of the universe, including radio waves, that penetrate everything?”

Another explanation attempts to justify discontinuity between mass and energy, by saying, “All matter has energy, unless it is at absolute zero temperature, true. But that amount of energy is tiny compared to the energy you could get if the matter were totally converted to energy via Einstein’s famous equation, E 5 mc2 . But there is no way for that to happen unless you are dealing with antimatter. Even the sun converts only a tiny percentage of the matter to energy, but that tiny percentage (because of the c2 term) produces a lot of energy.” In this, the notion of “antimatter” is invoked.

Natural light or heat is a measure of radiation from a system (called “material” in the above section). This radiation is continuous and accounts for change in mass within a system. In this, there is no difference between heat generation and light generation, nor there is any difference in radiation of different types of “radiation” (such as x-ray, gamma-ray, visual light, and infrared) other than they are of various frequencies. This can be reconciled with New Science for the limiting cases that say that there is an exponential relationship between reactants and products (Arrhenius equation) through the time function. Such relationship is continuous in time and space. For instance, as long as the assumption of continuity is valid, any substance is going to react with the media. The term “reaction” here implies formation of a new system that will have components of the reactants. This reaction has been explained by Khan et al. (2008) as a collection of snowflakes to form an avalanche. Islam et al. (2014) developed a similar theory that also accounts for energy interactions and eliminates separate balance equations for mass and energy. This theory considers energy or mass transfer (chemical reaction or phase change) as merger of two galaxies. Before merger, the two galaxies have different sets of characteristic frequencies. However, after merger, a new galaxy is formed with an entirely new set of characteristic frequencies. Such phenomena is well understood in the context of cosmic physics. Picture 4.2 shows NASA picture of two galaxies that are in a collision course. Cowen (2012) reported the following explanation: Four billion years from now, the Milky Way, as seen from Earth in this illustration, would be warped by a collision with the Andromeda galaxy. It’s a definite hit. The Andromeda galaxy will collide with the Milky Way about 4 billion years from now, astronomers announced today. Although the Sun and other stars will remain intact, the titanic tumult is likely to shove the Solar System to the outskirts of the merged galaxies.

Such collision does not involve a merger of two suns or any planets or moons. It simply means a reorientation of the stars and planets within a new family. Note how conservation of mass is strictly maintained as long as an artificial boundary is not imposed. In new science, such artificial boundary is imposed by confining a system within a boundary and

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PICTURE 4.2 An artist’s impression shows a stage in the merger between Milky Way Galaxy and the neighboring Andromeda galaxy (NASA / ESA / Z. Levay / R. van der Marel / STScI / T. Hallas / A. Mellinger).

imposing “no-leak” boundary conditions. Similarly, adiabatic conditions are imposed after creating artificial heat barriers. With the galaxy model, physical or chemical changes can both be adequately described as change in overall characteristic frequency. So, how does heat or mass gets released or absorbed? As stated above, “the titanic tumult” would cause the stars to be “shoved” toward the outskirts of the newly formed galaxy. In case, they are indeed placed around the outskirts, this would translate into excess heat near the boundary. However, if those stars are “shoved” inside the new giant galaxy, for an outsider, it would appear to be a cooling process, hence, endothermic reaction. In this context, the “titanic tumult” is equivalent to the “spark” that lights up a flame or starts a chain reaction. It is also equivalent to the onset of life or death as well as “big bang” in the universal sense. Even though these terms have been naturalized in New science vocabulary, they do not bear scientific meaning. Islam et al. (2012, 2014) recognized them to be unknown and unexplainable phenomena that cause onset of a phase change. They can be affected by heat, light, pressure that are direct results of changes within the confine of a certain system. The source of heat is associated to “collisions” as represented above in the context of galaxies, be it in subatomic level (known as chemical reactions), in combustion within a flame, or in giant scale (such as solar radiation). For our system of interest, that is, the earth, our primary source of heat is the sun that radiates mass in various wavelengths. New science recognizes “the solar constant” as the amount of power that the Sun deposits per unit area that is directly exposed to sunlight. The solar constant is equal to approximately 1368 W/m2 at a distance of one astronomical unit (AU) from the Sun (that is, on or near Earth). Sunlight at the top of Earth’s atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light. In another word, the heat source is inherently linked to light source. As discussed in previous sections, this transition between different forms of energy is continuous and should be considered to be

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part of the same phenomenon characterized here as “dynamic nature of everything in creation.” These are not “mass-less” photons or “energy-less” waves, they are actually part of mass transfer that originates from radiation of the Sun. Before solar emissions enter the atmosphere of the earth, nearly one-third of the irradiative material are deflected through filtering actions of the atmospheric particles. How does it occur? It is similar to the same process described above as galactic collision. During this process, the composition of the atmospheric layer changes continuously and “new galaxies” form continuously in the “tumult” mode, while some of the material are deflected outside the atmosphere and the rest penetrating the atmosphere to trigger similar “tumult” events through various layers of the atmosphere.

4.8.2 Transition of matter from the sun to the earth These atmospheric layers are such that all the layers act similar to a stacked-up filtering system. Following is a brief description of different layers of the atmosphere: 1. The exosphere is the thinnest (in terms of material concentration) layer. This is the upper limit of the Earth atmosphere. 2. The thermosphere is a layer with auroras. This layer sees intensive ionic activities. 3. The next layer is mesosphere. This is the layer that burns up meteors or solid fragments. The word “solid” implies most passive levels of activities of the constitutive material. Here, “solid” represents collection of “dust specks” that exhibit the slowest characteristic speed. Meteors or rock fragments burn up in the mesosphere. Another way to characterize matter in terms of solid liquid and vapor state. Within earth, the following configuration applies. It is possible that such configuration of various states will apply to other celestial entities, but that is not the subject of interest in the current context. 4. The next layer of the atmosphere, called stratosphere, is the most stable layer of the atmosphere. Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun. By the time, sunrays enter the final and fifth layer, almost 30% of the total irradiation have been removed. What energy (in form of light and heat) is ideal for rendering the earth system totally sustainable and ideal for human habitation. This layer is the most vulnerable to human intervention and is the cause of global warming (Islam and Khan, 2019). 5. The closest layer to the earth surface is troposphere. This layer contains half of the Earth’s atmosphere. All transient phenomena related to weather occur in this layer. This layer too contributes to attenuation of sunlight and at the end some 1000 W/m2 falls on the earth when the sky is clear and the Sun is near the zenith. The multiple filtering system of the atmosphere is such that it filters out 70% of solar ultraviolet, especially at the shorter wavelengths. The immediate use of solar energy in terms of sustaining human life is photosynthesis—the process that allows plants to capture the energy (through mass transfer) of sunlight and convert it to “live” chemical form. The energy stored in petroleum and other fossil fuels was originally converted from sunlight by photosynthesis in the distant past.

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The most significant is the photosynthetic mechanism. There are two classes of the photosynthetic cycle, the Calvin
Benson photosynthetic cycle and the Hatch
Slack photosynthetic cycle. The Calvin-Benson photosynthetic cycle is dominant in hard woods and conifers. The primary CO2 fixation or carboxylation reaction involves the enzyme ribulose1,5-diphosphate carboxylase and the first stable product is a 3-carbon compound. This reaction is considered to be “light-independent.” This series of reactions occur in the fluid-filled area of a chloroplast outside of the mytosis membranes. These reactions take the lightdependent reactions and perform further chemical processes on them. Various stages of this process are: carbon fixation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration. In describing this cycle of reactions, the role of light energy is marginalized. This process occurs only when light is available. Plants do not carry out the Calvin cycle by night. They instead release sucrose into the phloem from their starch reserves. This process happens when light is available independent of the kind of photosynthesis (C3 carbon fixation, C4 carbon fixation, and Crassulacean Acid Metabolism). The exceptions are: Crassulacean acid metabolism, also known as CAM photosynthesis, a carbon fixation pathway that is used by some plants as an adaptation to arid conditions. In a plant using full CAM, the stomata in the leaves remain shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide (CO2). The CO2 is stored as the four-carbon acid malate, and then used during photosynthesis during the day. The precollected CO2 is concentrated around the enzyme RuBisCO, increasing photosynthetic efficiency. On the other hand, the Hatch
Slack photosynthetic cycle is the one used by tropical grasses, corn and sugarcane. Phosphenol-pyruvate carboxylase is responsible for the primary carboxylation reaction. The first stable carbon compound is a C-4 acid, which is subsequently decarboxylated. It is then refixed into a three-carbon compound. These three steps define the canonical C4 photosynthetic pathway. Overall, the photosynthesis process shows how nature converts energy into mass, storing energy for long-term use. This must be understood in order to appreciate the role of natural processing in the context of petroleum usage. The process of energy-to-mass conversion is greatly affected by temperature. Sometimes temperatures are used in connection with day length to manipulate the flowering of plants. Chrysanthemums will flower for a longer period of time if daylight temperatures are 50 F. The Christmas cactus forms flowers as a result of short days and low temperatures. Also, temperatures alone also influence flowering. Daffodils are forced to flower by putting bulbs in cold storage in October at 35 F
40 F. The cold temperature allows the bulb to mature. The bulbs are transferred to the greenhouse in midwinter where growth begins. The flowers are then ready for cutting in 3
4 weeks. Plants produce maximum growth when exposed to a day temperature that is about 10 F
15 F higher than the night temperature. This allows the plant to photosynthesize (build up) and respire (break down) during an optimum daytime temperature, and to curtail the rate of respiration during a cooler night. High temperatures cause increased respiration, sometimes above the rate of photosynthesis. This means that the products of photosynthesis are being used more rapidly than they are being produced. For growth to occur, photosynthesis must be greater than respiration. Temperature alone can affect this process. Low temperatures can result in poor growth. Photosynthesis is slowed down at low temperatures. Since photosynthesis is slowed, growth is slowed, and this results in lower yields. Each plant has an optimum temperature that allows maximum growth. For

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example, snapdragons grow best when night time temperatures are 55 F, while the poinsettia grows best at 62 F. Florist cyclamen does well under very cool conditions, while many bedding plants grow best at a higher temperature. Buds of many plants require exposure to a certain number of days below a critical temperature before they will resume growth in the spring. Peaches are a prime example; most cultivars require 700
1000 hours below 45 F and above 32 F before they break their rest period and begin growth. This time period varies for different plants. The flower buds of forsythia require a relatively short rest period and will grow at the first sign of warm weather. During dormancy, buds can withstand very low temperatures, but after the rest period is satisfied, buds become more susceptible to weather conditions, and can be damaged easily by cold temperatures or frost. This series of phenomena have immediate implications to seeds and future of the biomass.

4.8.3 The nature of material resources As stated earlier, New Science has moved away from natural resources. In order to assess what resources we have we must reexamine how natural materials behave. Within the earth, the time function continuously drives matter with changes that follow natural transitions. Fig. 4.49 shows how matter transits through various stages with different degrees of characteristic speed. Although this figure represents continuous physical

FIGURE 4.49

Characteristic speed (or frequency) can act as the unique function that defines the physical state

of matter.

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transition, chemical transition as well as transition between energy and mass can also be represented with the same graphic. This is because each of these transitions represent characteristic speed change of each particle involved. It is possible that such configuration of various states will apply to other celestial entities, but that is not the subject of interest in the current context. Note that natural state of matter is an important consideration, particularly in relation to environmental sustainability. Note that natural state of matter is an important consideration, particularly in relation to human species and life. For instance, the most abundant matter on earth is water is the most useful for human species in its liquid state. It turns out water is also the most abundant in liquid state. In solid, clayey matter (SiO2) is the most abundant solid and scientists are beginning to find out humans are also made out of such matter. Here is a quote from Daily mail (2013): The latest theory is that clay - which is at its most basic, a combination of minerals in the ground - acts as a breeding laboratory for tiny molecules and chemicals which it ‘absorbs like a sponge’. The process takes billions of years, during which the chemicals react to each other to form proteins, DNA and, eventually, living cells, scientists told the journal Scientific Reports. Biological Engineers from Cornell University’s department for Nanoscale Science in New York state believe clay ‘might have been the birthplace of life on Earth’. It is a theory dating back thousands of years in many cultures, though perhaps not using the same scientific explanation.

This article refers to the work of Prof. Luo, whose group published the link between clay material and DNA (Hamada et al., 2014). Clay also retains the most amount of water—the most essential ingredient of life and organic material. As would be seen in other chapters as well as later in this section, similar optima exist in terms of visible light being the most abundant of sunlight rays and earth being the densest of all the planets in the solar system. Overall, all characteristic features for the earth makes it the most suitable as a “habitat for mankind” (Khan and Islam, 2016). This is how sustainability is linked to natural state of the earth. As such, the rest of this chapter will have a discussion of available resources in nature, starting with the most abundant resources, namely, water and petroleum.

4.8.4 The science of water and petroleum As discussed in previous sections, water is the most abundant resource on earth. Petroleum is the second most abundant fluid available on earth. As in early ancient Greek, ancient Chinese, and ancient Mesopotamia, water has been considered as the one that gives life while fire is the one that causes death. For fire to exist and complete the cycle of life, it must be accompanied with fuel, which is the essence of energy. While the role of water in creating sustaining life is well recognized, the role of petroleum has been mischaracterized. Such mischaracterization is unique to the modern epoch and is paradoxical (Islam et al., 2010). This “bad

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name” comes from the original paradox, called “water
diamond paradox,” first reported by Adam Smith, the father of Eurocentric economics. This paradox (also known as paradox of value) is the apparent contradiction that, although water is on the whole more useful, in terms of survival, than diamonds, diamonds command a higher price in the market. In a passage of Adam Smith’s An Inquiry into the Nature and Causes of the Wealth of Nations, he discusses the concepts of value in use and value in exchange, setting stage for bifurcating trends in value in utility and value in exchange: “What are the rules which men naturally observe in exchanging them [goods] for money or for one another, I shall now proceed to examine. These rules determine what may be called the relative or exchangeable value of goods. The word VALUE, it is to be observed, has two different meanings, and sometimes expresses the utility of some particular object, and sometimes the power of purchasing other goods which the possession of that object conveys. The one may be called “value in use”; the other, “value in exchange.” The things which have the greatest value in use have frequently little or no value in exchange; on the contrary, those which have the greatest value in exchange have frequently little or no value in use. Nothing is more useful than water: but it will purchase scarce anything; scarce anything can be had in exchange for it. A diamond, on the contrary, has scarce any use-value; but a very great quantity of other goods may frequently be had in exchange for it.”

Adam Smith, then explained, “the real value.” Furthermore, he explained the value in exchange as being determined by labor: The real price of every thing, what every thing really costs to the man who wants to acquire it, is the toil and trouble of acquiring it.

Instead of removing this paradox by finding a direct function that relates price with utility, pragmatic approach led to the resolution of this paradox by imposing price
production relationship and detaching consumers from the equation. In essence, this denomination of “value” created the basis for an inherently unsustainable pricing that in itself became the driver of technology development (Zatzman, 2012a, 2012b). Fig. 4.50 shows how assigning artificial value has led to a preposterous functionality FIGURE 4.50 Rendering real value into artificial loss, while profiteering.

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between real value and natural state. It turns out that the more detached any material is from its natural state the greater is the profit margin. This mindset has propelled modern era into creating the entire chemical engineering industry, aimed at denaturing materials in order to add monetary value while destroying environmental integrity (Islam and Jaan et al., 2018a). In scientific terms, the above manipulation amounts to removing the time function from each of the processes. Only then can the utility of carbon in charcoal and carbon in diamond can be conflated (Picture 4.3). By contrast, sustainability is inherent to natural state of matter and energy (Khan and Islam, 2007). Note how the sunlight is the primary source of energy, which is used to transform inorganic materials into organic ones. Such transformation cannot take place in absence of water (H2O) and carbon dioxide (CO2). During this transformation, sunlight plays the role of a catalyst and its contribution is quantifiable with proper science (Islam and Khan, 2019). However, sunlight is not sufficient as the onset of life is the phenomenon that triggers conversion of inorganic matter into organic matter. Scientifically, water represents the onset of life, whereas oil represents the end of life. Indeed, water and hydrocarbon contain an array of contrasting, yet complimentary properties. Fig. 4.51 depicts this nature of the water hydrocarbon duality. Note that in general petroleum represents the most stable form of carbon and hydrogen bond. Fig. 4.51 also shows how each segment of the yin
yang gives rise to other yin
yang in the form of oxygen/hydrogen and hydrogen/Water duality. As stated in previous sections, the duality continues even in subatomic level. In a broader sense, water is polar and is a good solvent due to its polarity. Oily materials are known to be hydrophobic. The ability of a substance to dissolve in water is determined by whether or not the substance can match or better the strong attractive forces that water molecules generate between other water molecules. If a substance has properties that do not allow it to overcome these strong intermolecular forces, the molecules are “pushed out” from the water and do not dissolve. Contrary to the common misconception, water and hydrophobic substances do not “repel,” and the hydration of a hydrophobic

PICTURE 4.3 The difference between charcoal and diamond can be captured in the time function, which is either linearized or altogether eliminated in various economic models that drive modern technology.

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FIGURE 4.51

4. Fundamentals of separation of oil and gas

Yin
Yang feature of the various components of water and petroleum.

surface is energetically favorable. The process of hydration can be best described by the process in which water molecules surround the molecule of another compound. Because, water molecules are relatively smaller, a number of water molecules typically surround the molecule of the other substance. This creates properties of water and oil that are different yet complementary. For instance, water and oil can form stable emulsions and eventually create soap. Life begins with water but ends with oil in its most stable and stabilized form. In fact, other than honey, oil is the most effective antibacterial natural liquid. On a molecular level, oil is hydrophobic but it is not water repellent. In fact, water molecules form very stable bonds around oil molecules. However, on a broader scale, oil kills but water gives life. On a microscale, they are opposite in every property but they are essential for life. This entire framework is depicted with the Yin
Yang symbol that not only bonds together opposites (historically it meant fire, water; life, death; male, female; earth, sky; cold, hot; black, white) but also are embedded inside white background, while holding within each another circle that itself has similar Yin
Yang structures. The cycle continues all the down to Higgs boson (until 2013) and beyond (in future), never reaching the same trait as the homogenous, anisotropic, monochrome,

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boundary-less surrounding. At every stage, there is also another combination of opposite, that is, intangible (time) and tangible (mass), which essentially is the program that defines the time function.

4.8.5 Comparison between water and petroleum Water is the source of life whereas petroleum is the end of a life cycle. These two form harmony in nature and coexist much like the Yin
Yang symbol. This fact was recognized throughout history and at no time petroleum products were considered harmful to the environment. In its fundamental unit, snowflakes represent modules of water, whereas diatoms represent organic units of petroleum (Picture 4.4). In its original form, symmetry exists but only in broad sense. There is no local symmetry. Picture 4.4 shows various images of snowflakes. If diamonds are from charcoal, petroleum is from its diatoms (Picture 4.5). Table 4.10 shows various sources of water on earth. Water and hydrocarbon are both essential to life, even though they play contrasting roles. Table 4.10 shows some of the unifying and contrasting features of water and petroleum. The above opposites signal complimentary nature of water and petroleum. At a molecular level, the following reactions of opposites can be observed: Oxygen 1 Hydrogen-Water

(4.19)

PICTURE 4.4 This single-celled green diatom won Rogelio Moreno Gill of Panama fifth place in the BioScapes Imaging Competition. Specimens for this composite image came from a lake (from National Geographic). Picture on the right is a snowflake. From U.S. Dept. of Agriculture.

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PICTURE 4.5 Diatoms.

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TABLE 4.10

Estimated global water distribution.

Water source

Water volume, in cubic miles

Water volume, in cubic kilometers

Percent of freshwater

Percent of total water

Oceans, Seas, & Bays

321,000,000

1,338,000,000




96.54

Ice caps, Glaciers, & Permanent Snow

5,773,000

24,064,000

68.7

1.74

Groundwater

5,614,000

23,400,000




1.69

Fresh

2,526,000

10,530,000

30.1

0.76

Saline

3,088,000

12,870,000




0.93

Soil Moisture

3959

16,500

0.05

0.001

Ground Ice & Permafrost

71,970

300,000

0.86

0.022

Lakes

42,320

176,400




0.013

Fresh

21,830

91,000

0.26

0.007

Saline

20,490

85,400




0.006

Atmosphere

3095

12,900

0.04

0.001

Swamp Water

2752

11,470

0.03

0.0008

Rivers

509

2120

0.006

0.0002

Biological Water

269

1120

0.003

0.0001

From Shiklomanov (1993).

The result is water vapor, with a standard enthalpy of reaction at 298.15K and 1 atm of 242 kJ/mol. While this equation is well known, it cannot be stated that natural water is created this way. In fact, all evidence suggest that it is not and the suggestion that oxygen and hydrogen combined to form water as the basis of life bears the same first premise as the one imposed for the Big Bang theory. What we know, however, is if hydrogen burns in oxygen, it produces intense heat (around 2000 C) as compared to heat of a natural flame (e.g., from candle) that is around 1000 C. The above reaction does not take place unless there is a presence of two other components, one tangible (catalyst) and one intangible (spark), that produce a flame. A discussion on what constitutes a flame and its consequences is presented in later chapters. This reaction needs a spark that itself has catalysts (tangible) and energy (intangible). One theory stipulates that water is the original matter. This is in contrast to popular theory that puts hydrogen as the original mass (Islam, 2014). Only recently this theory has gained ground as astrophysicists continue to find evidence of water in outer space (Carr and Najita, 2011; Hogerheijde, et al., 2011; Lammer et al., 2013). Table 3.5. lists the fundamental properties of oxygen and hydrogen. Table 3.6 lists the fundamental properties of oxygen and hydrogen. Table 3.7 highlights qualities that unite and contrast oxygen and hydrogen. Carbon 1 Oxygen-Carbon dioxide

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The above reaction takes place at all temperature (e.g., low-temperature oxidation). However, the most natural, yet rapid conversion takes place with fire. Fire itself has tangible (mass of fire) and energy (heat of reaction, intangible). Table 6.14 lists the fundamental properties of oxygen and carbon. Table 6.15 highlights qualities that unite and contrast oxygen and carbon. Similar effects are expected with pressure. Photosynthesis offers an example of a natural effect of pressure on organic reactions. Beer and Waisel (1982) studied photosynthetic responses to light and pressure (up to 4 atm) for two seagrass species abundant in the Gulf of Eilat (Red Sea). In Halodule uninervis (Forssk.) Aschers. Pressure decreased net photosynthetic rates, while in Halophila stipulacea (Forssk.) Aschers. Pressure had no effect on net photosynthetic rates. In both species, light saturation was reached at 300 μE (400
700 nm) m22/s1 and the compensation point was at 20
40 μE (400
700 nm) m22/s. Comparing these results to in situ light measurements, neither species should be light limited to a depth of about 15 m, and Halophila stipulacea should reach compensation light intensities at about 50 m. The latter depth corresponds well to the natural depth penetration of this species. Halodule uninervis is never found deeper than 5 m in the Gulf of Eilat, and it appears that pressure rather than light is one of the factors limiting the depth penetration of this species. The differential pressure response of the two species may be related to aspects of leaf morphology and gas diffusion. Scientifically, confining pressure is responsible for creating a series of vibrations that are in conflict with natural frequencies of matter. Because of continuity of matter, the external vibrations cause reactions to matter that attempt to escape its confinement. Pressure, alone can cause a series of oscillatory events that prompt fundamental changes in the subatomic structure of matter. The vast majority of water on the Earth’s surface, over 96%, is saline water in the oceans. The freshwater resources, such as rain water, water from streams, rivers, lakes, and groundwater, provide people with the water they sustain lives. Only recently, it has come to light that the Earth’s mantle contains much more water than the surface water (Williams, 2014) (Table 4.11).

4.8.6 Contrasting properties of hydrogen and oxygen Table 4.12 shows the contrasting properties of hydrogen and oxygen. These contrasting and complementary properties of hydrogen and oxygen and oxygen and carbon give rise to water and fire, respectively, creating a new set of contrasting and complementary components. Together, they form the basic ingredients of life on earth and exemplify natural sustainability. Hydrogen has the atomic number 1, and has 1 electron and 1 proton. Within the galaxy model (that does not include any fictitious entity as proton and electron), this means uniqueness in terms of its ability to take part in the formation of chemical bonds according to a donor-acceptor mechanism. As such, hydrogen is a strong reducer, thereby making in the first group leading the alkaline metals as the most active. In the reduction process, hydrogen in fact becomes an oxidizer (in terms of receiving an electron). These compounds are called hydrides. For this property, hydrogen leads the subgroup of halogens, with which it shares similarities. Hydrogen is the lightest element and it resembles no other element. At high pressures, snow-like crystals of solid hydrogen form. One uniqueness of hydrogen is its ability to behave like metals under extreme pressures. This has been long been theorized (e.g., Anisimov and Popov, 1986) but experimental evidence only came recently. Dias and Silvera (2017) published evidence of solid metallic hydrogen that was synthesized in the laboratory

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TABLE 4.11

Contrasting features of water and petroleum.

Water

Petroleum

Source of all organic matter

End product of all organic matter

Most abundant fluid on earth

Second most abundant fluid on earth

Oxygen 85.84; Sulfur 0.01, Hydrogen 10.82; Calcium 0.04; Chlorine 1.94; Potassium 0.04; Sodium 1.08; Bromine 0.0067; Magnesium 0.1292; Carbon 0.0028

Carbon, 83%
87% Hydrogen, 10e 14% Nitrogen, 0.1e 2% Oxygen, 0.05e 1.5% Sulfur, 0.05%
6.0% Metals ,0.1% Hydrocarbon (15e 60%), napthenes (30%
60%), aromatics (3%
30%), with asphaltics making up the remainder. Non-reactive toward metal

Reactivity of water toward metals: Alkali metals react with water readily. Contact of cesium metal with water causes immediate explosion, and the reactions become slower for potassium, sodium, and lithium. Reaction with barium, strontium, calcium are less well known, but they do react readily. Reaction with nonmetals is faster Nonmetals like Cl2 and Si react with water Cl2(g). H2O(l)/HCl(aq). HOCl(aq) Si(s). 2H2O(g)/SiO2(s). 2H2(g) Some nonmetallic oxides react with water to form acids. These oxides are referred to as acid anhydrides. High cohesion

Low cohesion

Unusually high surface tension;

Unusually low surface tension;

susceptible to thin film

Not likely to have thin films

Adhesive to inorganic

Nonadhesive to inorganic

Unusually high specific heat

Unusually low specific heat

Unusually high heat of vaporization

Unusually low heat of vaporization

Has a parabolic relationship between temperature and density

Has monotonous relationship between temperature and density

Unusually high latent heat of vaporization and freezing

Unusually low latent heat of vaporization and freezing

Versatile solvent

Very poor solvent

Unusually high dielectric constants

Unusually low dielectric constants

Has the ability to form colloidal solutions

Destabilizes colloids

Can form hydrogen bridges with other molecules, giving it the ability to transport minerals, carbon dioxide, and oxygen

Poor ability to transport oxygen and carbon dioxide

Unusually high melting point and boiling point

Unusually low melting point and boiling point

Unusually poor conductor of heat

Unusually good conductor of heat (Continued)

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TABLE 4.11 (Continued) Water

Petroleum

Unusually high osmotic pressure

Unusually low osmotic pressure

Nonlinear viscosity pressure and temperature Mild nonlinearity in viscosity pressure and relationship (extreme nonlinearity at nanoscale, Hussain temperature relationship and Islam, 2009) Enables carbon dioxide to attach to carbonate

Absorbs carbon dioxide from carbonate

Allows unusually high sound travel Large bandwidth microwave signals propagating in dispersive media can result in pulses decaying according to a nonexponential law (Peraccini et al., 2009)

Allows unusually slow sound travel

Unusually high confinement of X-ray movement (Davis et al., 2006)

Unusually high facilitation of X-ray movement

Allows unusually slow sound travel Large bandwidth microwave signals propagating in dispersive media can result in pulses decaying according to a nonexponential law (Pieraccini, 2008). Faster than usual movement of microwave

TABLE 4.12 Opposing properties of hydrogen and oxygen. Oxygen

Hydrogen

Atomic number

8

1

Atomic mass

15.999 g/mol

1.007825 g/mol

Electronegativity according to Pauling

3.5

2.1

Density

1.429 kg/m at 20 C

0.0899 kg/m3 at 20 C

Melting point

2219 C

2259.2 C

3



Boiling point

2183 C

2252.8 C

Van der Waals radius

0.074 nm

0.12 nm

Ionic radius

0.14 nm (22)

0.208 nm (21)

Isotopes

4

3 2

4

Electronic shell

[He] 2s 2p

1s1

Energy of first ionization

1314 kJ/mol

1311 kJ/mol

Energy of second ionization

3388 kJ/mol

Energy of third ionization

5300 kJ/mol

Flammability

Pure oxygen not flammable

Pure hydrogen is highly flammable

Abundance in human body

Most abundant (65%)

Least abundant among major components (oxygen, carbon, 18% and hydrogen, 9.5%)

Magnetism

Paramagnetic

Weak magnetism

Discovered by

Joseph Priestly in 1774

Henry Cavendish in 1766

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at a pressure of around 495 gigapascals (4,890,000 atm; 71,800,000 psi) using a diamond anvil cell. The reflectance using a Drude free electron model to determine the plasma frequency of 30.1 eV at T 5 5.5K, with a corresponding electron carrier density of 6.7 3 1023 particles/ cm3 was consistent with theoretical estimates. These properties are those of a metal. Fig. 4.52 shows potential phase diagram for hydrogen. In contrast to oxygen, hydrogen is immiscible in water. It is a nonmetal with properties that are consistent with nonmetals. Animals and plants require oxygen for respiration. As such, it is the most essential component for human life. Death may occur within minutes of oxygen deprivation. While the gas is essential for life, too much of it can be toxic or lethal. As much as 50% oxygen can trigger various symptoms of oxygen poisoning, such as vision loss, coughing, muscle twitching, and seizures. Liquid and solid oxygen are pale blue. At lower temperatures and higher pressures, oxygen changes its appearance from blue monoclinic crystals to orange, red, black, and even a metallic appearance. Although oxygen can reach solid state under much less restrictive conditions as hydrogen, its thermal and electrical conductivity values remain very low (see Fig. 4.53). The triple point for oxygen is approximately 386K and 11.5 GPa (Fig. 4.53). Oxygen electronegativity and ionization energy are much higher than hydrogen. The solid form of oxygen is brittle rather than malleable or ductile. FIGURE 4.52

Phase diagram of hydrogen. Source: From

Service (2017).

FIGURE 4.53 Nicol (1987).

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Oxygen gas normally is the divalent molecule O2. Ozone, O3, is another form of pure oxygen. Atomic oxygen, which is also called “singlet oxygen” does occur in nature, although the ion readily bonds to other elements. Singlet oxygen is not likely to be found outside of the upper atmosphere. A single atom of oxygen usually has an oxidation number of 22. Oxygen is most essential for combustion. However, it is not flammable (pure oxygen does not burn) and it is rather an oxidizer. Oxygen is paramagnetic, which means it is weakly attracted to a magnet but does not retain permanent magnetism. This is in contrast to hydrogen that has very weak magnetism. Approximately 2/3 of the mass of the human body is oxygen. This makes it the most abundant element, by mass, in the body. Much of that oxygen is part of water. Oxygen is also the most abundant element in the Earth’s crust (about 47% by mass) and the third most common element in the Universe. However, this account is disputable because latest evidence suggests that oxygen is rarely in elemental form in the galactic system. When hydrogen is heated, a combination reaction takes place between the element and simple substances—chlorine, sulfur, and nitrogen. The reaction of hydrogen with oxygen takes place as follows: when pure hydrogen released from a gas tube is ignited in air, the gas burns with an even flame. The combustion of hydrogen is accompanied by a high release of heat. The temperature of the hydrogen-oxygen flame reaches over 2000 C. The most explosive concentration of hydrogen and oxygen is a mixture from 4% to 96% by volume. This remains an active topic of research, in which scientists are investigating the little-studied property of hydrogen to self-combust from a drastic drop in pressure. Table 4.13 gives the complete list of contrasting and unifying features of hydrogen and oxygen. TABLE 4.13 Similar and contrasting properties of hydrogen and oxygen. Oxygen

Hydrogen

Fundamental component of water (89% in mass and 33% in mole), which is ubiquitous on earth (70%).

Fundamental component of water (11% in mass and 67% in mole), which is ubiquitous on earth (70%)

Believed to be 3rd most abundant element in universe

Believed to be most abundant element in universe

If mass-energy discontinuity is removed, most abundant mass in universe

If mass-energy discontinuity is removed, second most abundant in universe

It is the essential element for respiratory processes for all living cells. It is the most abundant element in the Earth’s crust. Nearly one-fifth (in volume) of the air is oxygen. Noncombined gaseous oxygen normally exists in form of diatomic molecules, O2, but it also exists in triatomic form, O3, ozone.

Hydrogen is the most flammable of all the known substances. There are three hydrogen isotopes: protium, mass 1, found in more than 99,985% of the natural element; deuterium, mass 2, found in nature in 0.015% approximately; and tritium, mass 3, which appears in small quantities in nature.

Oxygen is reactive and will form oxides with all other elements except helium, neon, argon, and krypton. It is moderately soluble in water (30 cm3/L of water dissolve) at 20 C. Oxygen does not react with acids or bases under normal conditions.

The dissociation energy of molecular hydrogen is 104 kcal/mol. Molecular hydrogen is not reactive. Atomic hydrogen is very reactive. It combines with most elements to form hydrides (e.g., sodium hydride, NaH), and it reduces metallic oxides, a reaction that produces the metal in its elemental state. The surfaces of metals that do not combine with hydrogen to form stable hydrides (e.g., platinum) catalyze the recombination of hydrogen atoms to form hydrogen molecules and are thereby heated to incandescence by the energy. (Continued)

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TABLE 4.13

283

(Continued)

Oxygen

Hydrogen

Strong bond with hydrogen (110 kcal/mol); slightly stronger bond with oxygen (119 kcal/mol).

Strong bond with oxygen; lesser strength bond with hydrogen (104 kcal/mol); lesser strength bond with carbon (98 kcal/mol).

The crust of earth is composed mainly of silicon-oxygen The earth crust has some 45 times less hydrogen than minerals, and many other elements are there as their oxygen oxides. Oxygen gas makes up one-fifth of the atmosphere. The oxygen in the Earth’s atmosphere comes from the photosynthesis of plants, and has built up in a long time as they utilized the abundant supply of carbon dioxide in the early atmosphere and released oxygen

Only 0.000055% of earth atmosphere is hydrogen. Sunlight causes photosynthesis that utilizes hydrogen and releases oxygen, forming a closed loop.

Oxygen is fairly soluble in water (0.045 g/kg of water at Low solubility in water (0.0016 g/kg of water at 20 C). 20 C), which makes life in rivers, lakes, and oceans possible. The water in rivers and lakes needs to have a regular supply of oxygen, for when this gets depleted the water will no longer support fish and other aquatic species. Low solubility in water (0.0016 g/kg of water at 20 C). Nearly every chemical, apart from the inert gasses, bind with oxygen to form compounds. Water, H2O, and silica, SiO2, main component of the sand, are among the more abundant binary oxygen compounds. Among the compounds which contain more than two elements, the most abundant are the silicates, which form most of the rocks and soils. Other compounds that are abundant in nature are calcium carbonate (limestone and marble), calcium sulfate (gypsum), aluminum oxide (bauxite), and various iron oxides that are used as source of the metal

At normal temperature, hydrogen is a not very reactive substance, unless it has been activated somehow; for instance, by an appropriate catalyzer. At high temperatures, it is highly reactive and a powerful reducing agent (antioxidant). It reacts with the oxides and chlorides of many metals, like silver, copper, lead, bismuth, and mercury, to produce free metals. It reduces some salts to their metallic state, like nitrates, nitrites, and sodium and potassium cyanide. It reacts with a number of elements, metals, and nonmetals, to produce hydrides, like NAH, KH, H2S, and PH3. Atomic hydrogen produces hydrogen peroxide, H2 O2, with oxygen.

Oxygen is essential for all forms of life since it is a constituent of DNA and almost all other biologically important compounds. Is it even more dramatically essential, in that animals must have minute by minute supply of the gas in order to survive. Oxygen in the lungs is picked up by the iron atom at the center of hemoglobin in the blood and thereby transported to where it is needed.

All compounds and elements produced through hydrogen reduction (see above) are potent toxins for all living organisms. However, organic form of the same toxin is necessary for living organisms. For instance, lack of organic H2S can trigger Alzheimer’s disease.

Departure from normal atmospheric composition of High concentrations of this gas can cause an oxygenoxygen (both too high or too low concentrations) causes deficient environment. Individuals breathing such an lung damage. In its pure form, it is toxic. atmosphere may experience symptoms that include headaches, ringing in ears, dizziness, drowsiness, unconsciousness, nausea, vomiting, and depression of all the senses. Under some circumstances, death may occur.

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4.8.7 The carbon
oxygen duality The most important reaction that takes place on earth is the photosynthesis. During photosynthesis, plants take in carbon dioxide to give off oxygen as a reaction product. In this process, the important transition from inorganic to organic form carbohydrate takes place. The sunlight acts as the catalyst. The primary energy source of the Earth is the sun. The sunlight is essential to photosynthesis that requires CO2 and water as well as the presence of a plant biomass. As such, CO2 is integral to the Energy
Water
Food nexus (Fig. 4.54). In an agricultural process, any artificial chemical added to the water or soil system will affect the quality of food. Equally impactful is the overall composition of the atmosphere and the temperature, because each of the oxidation reactions is a sensitive function of temperature and composition. Even a small amount of toxins can alter the natural pathway irreversibly through catalytic actions. Considering the fact that nature is continuous, meaning there is no barrier to either mass or energy transport, not a single particle of mass (thus energy) can be isolated, any point is inflicted with toxicity will have an impact on the rest of the ecosystem. All animals, including humans, require oxygen to survive. Animals breathe in the oxygen made by plants and breathe out carbon dioxide as a waste product. Even animals that live underwater need oxygen. These animals pass water over their gills to take in dissolved oxygen that is made by water plants. The water plants in turn take in the dissolved carbon dioxide from the water. Animals and plants are connected to each other by the oxygen
carbon dioxide cycle. Plants need the carbon dioxide from animals to live and animals must have the oxygen from plants to survive. Table 4.14 shows characteristic properties of carbon. Carbon has an atomic number of six. What water is to rest of the creation, carbon is to living entities. Without carbon, there would be no living cell. As such, carbon is also central to organic life supporting major compounds. These compounds include carbohydrates, lipids, proteins, and nucleic acids.

FIGURE 4.54 The water
food
energy nexus. Source: From Lal (2013).

d de ee d is n foo ter w o Wa gr to r ts po r ns te tra ) wa od al Fo virtu (

to Wat ge er ne is n rat ee e e de ne d En rgy to ergy su is pp ne ly ed wa ed ter

Water

Energy is needed to produce food

Energy (Sunlight)

Food can be used to produce energy

Food CO2

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TABLE 4.14

Characteristic properties of carbon.

Atomic number

6

Atomic mass

12.011 g/mol

Electronegativity according to Pauling

2.5

Density

2.2 g/cm3 at 20 C

Melting point

3652 C

Boiling point

4827 C

Vanderwaals radius

0.091 nm

Ionic radius

0.26 nm (24); 0.015 nm (14)

0.26 nm (24); 0.015 nm (14) Isotopes

3

3 [He] 2s22p2

Electronic shell [He] 2s22p2 Energy of first ionization

1086.1 kJ/mol

1086.1 kJ/mol Energy of second ionization

2351.9 kJ/mol

2351.9 kJ/mol Energy of third ionization

4618.8 kJ/mol

From Islam (2014).

Carbon is uniquely equipped to be the most important component in each of these compounds. Carbon has an exceptional ability to bind with a wide variety of other elements. Carbon makes four electrons available to form covalent chemical bonds, allowing carbon atoms to form multiple stable bonds with other small atoms, including hydrogen, oxygen, and nitrogen. These bonds are central to the water cycle, carbon cycle, and nitrogen cycle that are considered to be the key to sustainability. Carbon atoms can also form stable bonds with other carbon atoms. In fact, a carbon atom may form single, double, or even triple bonds with other carbon atoms. This allows carbon atoms to form a tremendous variety of very large and complex molecules. This enables carbon to form very long chains of interconnecting C
C bonds, which are the backbone of organic life. Today, nearly 10 million carboncontaining organic compounds are known. Types of carbon compounds in organisms include carbohydrates, lipids, proteins, and nucleic acids. Petroleum products are various forms of such carbon bonds. Table 4.15 lists examples of some of these compounds and their major function in a living body. Organic compounds act as the “mother” molecules and when smaller groups are formed with elements other than carbon and hydrogen, the reactions with other groups are usually limited to exchange of functional group (made out of nonhydrogen and carbon). The nature of the resulting products depends on the functional group.

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TABLE 4.15 Major organic compounds and their functions. Type of compound

Elements it contains

Examples

Functions

Carbohydrates carbon, hydrogen, oxygen

Glucose, Starch, Glycogen

provides energy to cells, stores energy, forms body structures

Lipids

carbon, hydrogen, oxygen

Cholesterol, Triglycerides (fats), Phospholipids

stores energy, forms cell membranes, carries messages

Proteins

carbon, hydrogen, oxygen, nitrogen, sulfur

Enzymes, Antibodies

helps cells keep their shape/structure, makes up muscles, catalyzes chemical reactions, carries messages and materials

Nucleic Acids

carbon, hydrogen, oxygen, nitrogen, phosphorus

Deoxyribonucleic acid (DNA), Ribonucleic acid (RNA), Adenosine Triphosphate (ATP)

contains instructions for proteins, passes instructions from parents to offspring, helps make proteins

TABLE 4.16 Natural polymers and their bonds. Polymer

Monomer

Bond

Carbohydrates

Monosaccharides

Glycosidic

Lipids

Fatty acid

Ester

Proteins

Amino acids

Peptide

Nucleic acids

Nucleotides

Phosphodiester

In an organic body, polymers are formed through so-called condensation reactions. This process is very different from how artificial polymers (plastics) are formed. This explains why natural polymers are inherently sustainable whereas artificial ones are inherently unsustainable (Islam et al., 2010). During condensation reactions, water is produced from the two molecules being bonded together. Table 4.16 lists the type of bonds and monomers involved in major condensation reactions. When combined with oxygen and hydrogen, carbon can form many groups of important biological compounds including carbohydrates (sugars), lignans (important in plants), chitins (the main component of the cell walls of fungi, the exoskeletons of arthropods), alcohols, lipids, and fats (triglycerides), and carotenoids (plant pigment). With nitrogen, it forms alkaloids, and with the addition of sulfur in addition to the nitrogen, it forms amino acids which bind together to form proteins, antibiotics, and rubber products. With the addition of phosphorus to these other elements, carbon forms nucleotides which bond into nucleic acids (DNA and RNA), and adenosine triphosphate (ATP), which is known as the energy currency of the cell. The properties of all these organic molecules is related to the composition of the elements that compose the molecule. Certain carbohydrates, proteins, and nucleic acids are known as macromolecules, as they are very large polymers made of individual monomers.

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Table 4.17 lists the contrasting and unifying features of oxygen and carbon. They are both integral part of the original yin
yang of water and fire, which represent tangible and intangible aspects of the entire universe. In New Science terminology, water and fire would represent mass and energy respectively. As anticipated in the yin
yang arrangement, the tangible (water) gives rise to intangible (oxygen) and intangible (fire) gives rise to tangible (carbon) and they are both integral part of the life cycle in broader sense. This is depicted in Fig. 4.55. Table 4.17 also shows oxygen and carbon pools. The main source of atmospheric free oxygen is photosynthesis, which produces natural sugars and free oxygen from carbon dioxide and water. In this process, sunlight and chlorophyll act as the intangible/tangible yin/yang duet. New Science is not capable of identifying the role of this role, let alone quantifying it. Fig. 4.57 shows how fire and water (sparked with the intangible that triggers fire) emit ingredients that go through a series of transformations in the presence of intangibles, such as sunlight and chlorophyll that in turn add life to the system, returning the tangible supply of oxygen and water, which then can complete the cycle. Photosynthesizing organisms include the plant life of the land areas as well as the phytoplankton of the oceans. It is estimated that between 30% and 85% of the world’s oxygen is produced via phytoplankton photosynthesis). Such wide range is because of the fact that we know little about the biomass in the ocean. In addition, the actual process in deep ocean is only vaguely explained by New Science. This fact has been abused by both sides of the climate change debate. One side argued that the use of pesticide and incessant dumping in the ocean will result in disaster on earth. The other side argues that several chlorinated hydrocarbons exhibit a selective effect on marine phytoplankton, strongly inhibiting photosynthesis and growth of some species while exerting no effect whatever on others (Ryther, 1970). It is concluded, therefore, that pesticides and other toxic pollutants may influence the species composition of phytoplankton than eliminate them entirely. Because there is no mechanism in New Science to track in quality of oxygen, as long as the phytoplankton is not entirely eliminated, the effect of pollutants is considered to be easily compensated by other plants. The assumption of equilibrium in production and consumption of oxygen among organic bodies. Such assumptions are inherently spurious and create obstacles to proper analysis (Islam and Khan, 2019). It is at this level that sustainability considerations should be made and clearly failing to account for events at this level makes it impossible to come up with a global sustainability model. Of significance is the fact that phytoplankton is also the primary dependent on minerals. These are primarily macronutrients such as nitrate, phosphate, silicic acid, and others. This process is essential to turning inorganic chemicals into organic material. It is known that phytoplankton thrives under balanced conditions, including traces of iron. This fact is known. However, New Science has abused this fact. For instance, the discovery of phytoplankton death in areas, stripped of iron has led some scientists to advocate iron fertilization as a means to activate phytoplankton growth. In some cases, large amount of iron salt (e.g., iron sulfate) has been added to promote phytoplankton growth, thereby acting as sink for atmospheric CO2 into the ocean. Similarly, the dependence of phytoplankton on Vitamin B for survival had prompted some scientists to contemplate using Vitamin B therapy. During the last few decades, such manipulation of the ocean system has subsided as mounting evidence surface that such manipulation is a danger to the ecosystem (Goordial et al., 2016; Li, 2017). However, the ocean manipulation has yielded to engineering of the

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TABLE 4.17 Contrasting and unifying features of oxygen and carbon. Oxygen

Carbon

Fundamental component of water (89% in mass and 33% in mole), which is ubiquitous on earth (70%).

Fundamental component of living organisms, second most abundant in mass, and third most abundant in atomic numbers.

The most abundant in mass and numbers. Most abundant in (65%) of a living body

Second most abundant (18%) of living body.

Believed to be third most abundant element in universe

Believed to be 4th most abundant element in universe

If mass-energy discontinuity is removed, most abundant mass in universe

If mass-energy discontinuity is removed, third most abundant (after oxygen and hydrogen) in universe.

Oxygen recycled through water cycle for sustenance of life

Carbon recycled through carbon cycle for sustenance of life

Oxygen burns hydrogen with the largest heat of reaction for any element (141.8 MJ/kg)

Oxygen burns carbon with the second largest heat of reaction for any element (32.8 MJ/kg)

Oxygen pool

Carbon pool a

Photosynthesis (land) 16,500 Photosynthesis (ocean) 13,500 Photolysis of N2O 1.3 Photolysis of H2O 0.03 Total gains B30,000

Losses: Respiration and Decay Aerobic respiration 23,000 Microbial oxidation 5100 Combustion of fossil fuel 1200 (anthropogenic) Photochemical oxidation 600 Fixation of N2 by lightning 12 Fixation of N2 by industry 10 (anthropogenic) Oxidation of volcanic gases 5 Losses: Weathering Chemical weathering 50 Surface reaction of O3 12 Total losses B30,000

Pool

Quantity (gigatons)

Atmosphere

720

Ocean (total)

38,400

Total inorganic

37,400

Total organic

1000

Surface layer

670

Deep layer

36,730

Lithosphere

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Sedimentary carbonates

. 60,000,000

Kerogens

15,000,000

Terrestrial biosphere (total)

2000

Living biomass

600
1000

Dead biomass

1200

Aquatic biosphere

1
2

Fossil fuels (total)

4130

Coal

3510

Oil

230

Gas

140

Other (Peat)

250

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TABLE 4.17 (Continued) Oxygen

Carbon

It is the essential element for respiratory processes for all living cells.

It is the second (second to hydrogen) most important fuel for living organism and sustenance of life.

It is the most abundant element in the earth’s crust.

Carbon is the 15th most abundant in earth’s crust.

Nearly one-fifth (in volume) of the air is oxygen.

Carbon, major component of all organic matter, but atmospheric carbon in the form of CO2 (around 400 ppm) and CH4 (not exceeding 2000 ppb). A mass of about 7 1011 tons of carbon is in the atmosphere as CO2 and about 4.5 1011 tons of carbon in vegetation as carbohydrate. The nominal percentage of CO2 in the atmosphere is about 0.034%.

Noncombined gaseous oxygen normally exists in the form of diatomic molecules, O2 but it also exists in triatomic form, O3, ozone.

Carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as of many minerals, such as limestone.

Oxygen, major component of water, is essential for life. By far the largest reservoir of earth’s oxygen is within the silicate and oxide minerals of the crust and mantle (99.5%).

Carbon is major component of dead bodies.

Only a small portion has been released as free oxygen to the biosphere (0.01%) and atmosphere (0.36%).

All elementary form remains in solid form.

The main source of atmospheric free oxygen is Main component of the reaction products of photosynthesis, which produces sugars and free oxygen photosynthesis from carbon dioxide and water. The sun is the biggest contributor to photosynthesis with Oxygen as the influx

The sun is the biggest contributor to photosynthesis with Carbon material as the effluent

Oxygen is reactive and will form oxides with all other elements except helium, neon, argon, and krypton.

Carbon’s best reactant is oxygen that produces CO2—the one needed for synthesis of carbohydrate.

Strong bond with hydrogen (110 kcal/mol); slightly stronger bond with oxygen (119 kcal/mol).

The C
O bond strength is also larger than C
N or C
C. C
C 5 83; C
O. 85.5; O
CO 5 110; C 5 5 O 5 192 (CO2); C 5 5 O. 177 (aldehyde); C. O (ketone) 5 178; C 5 5 O (ester) 5 179; C 5 5 O (amide) 5 179; C  O 5 258; C C 5 200 (all values in kcal/mole)

The crust of earth is composed mainly of silicon oxygen minerals, and many other elements are there as their oxides. Oxygen gas makes up one-fifth of the atmosphere.

After nitrogen, oxygen, and argon, carbon dioxide is the most abundant component of earth’s atmosphere. Other forms of Carbon (e.g., Methane) are not volumetrically significant. (Continued)

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TABLE 4.17 (Continued) Oxygen

Carbon

The oxygen in the earth’s atmosphere comes from the photosynthesis of plants, and has built up in a long time as they utilized the abundant supply of carbon dioxide in the early atmosphere and released oxygen.

The carbon dioxide comes from respiration of living organisms.

Oxygen is fairly soluble in water (0.045 g/kg of water at Very low solubility in water 20 C), which makes life in rivers, lakes, and oceans possible. Nearly every chemical, apart from the inert gasses, bind Quite Inert with the exception of oxygen, hydrogen, with oxygen to form compounds. and nitrogen. Time purifies carbon (e.g., diamond, graphite) Oxygen is essential for all forms of life since it is a constituent of DNA and almost all other biologically important compounds. Sets direction of the natural pathway.

Mechanical portion of living organism. Uniquely suited for metabolism. It is the driven portion of the body. The two most important characteristics of carbon, as a basis for the chemistry of life, are that it has four valence bonds and that the energy required to make or break a bond is just at an appropriate level for building molecules that are not only stable, but also reactive. The fact that carbon atoms bond readily to other carbon atoms allows for the building of arbitrarily long complex molecules and polymers.

Departure from normal atmospheric composition of Departure from natural state of earthly material causes oxygen (both too high or too low concentrations) causes ailment. lung damage. Time facilitates oxidation, diversifying composition of the surrounding chemicals.

Time purifies carbon (e.g., diamond, graphite)

In its pure elemental form, oxygen is susceptible to violent reaction through oxidation.

In its elemental form (graphite and diamond), is completely a benign and great fuel, only second to hydrogen as an elemental energy generator.

Oxygenation “age” materials and lead to degeneration.

Some simple carbon compounds can be very toxic, such as carbon monoxide (CO) or cyanide (CN). Larger molecules become benign.

a In units of 1012 kg/year. From Islam (2014) and Falkowski et al. (2000).

atmospheric system, which now includes spraying of sulfuric acid into the lower stratosphere, around 60,000 feet up (Islam and Khan, 2019). Table 4.18 lists the contrast in oxygen and carbon reservoirs. The most important feature of this table is the maintenance of natural equilibrium in section of the earth/atmosphere system. Anytime, equilibrium is perturbed in section, it would result in a chain of events creating global imbalance. It may not evident in a short time, but eventually, the effects will accumulate and a “tipping point” will be reached.

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FIGURE 4.55 Carbon
oxygen duality is linked to fire water duality.

TABLE 4.18

Contrast in reservoir in oxygen and carbon reservoirs. Oxygen reservoir

Carbon reservoir

Reservoir

Capacity (kg O2)

Flux (kg/year)

Residence time (years)

Reservoir

Size (gigatons of Carbon)

Atmosphere

1.4.1018

3.1014

4500

Atmosphere

750

16

14

50

Forests

610

11

500,000,000

Soils

1580

Surface ocean

1020

Deep ocean

38,100

Coal

4000

Oil

500

Natural gas

500

Biosphere Lithosphere

1.6.10

20

2.9.10

3.10 6.10

4.9 The science of lightening Although this chapter is about energy or natural energy to be specific, the role of lightening in the nitrogen cycle and its role in sustaining organic lives, this discussion is presented before the discussion of nitrogen cycle. This section will prepare the readership in appreciating the nature of sustainable energy. The enormous energy of lightning breaks nitrogen molecules and enables their atoms to combine with oxygen in the air forming nitrogen oxides. These dissolve in rain, forming nitrates, that are carried to the earth. In this process, the lightening is the source of the chemical change. As such, it must be noted that lightening is a natural process and is very different from electricity that is produced commercially (both static and dynamic forms).

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During lightening, avalanches of relativistic runaway “particles,”2 which develop in “electric” fields within thunderclouds (Gurevich et al., 1992; Dwyer, 2012). Within this field, deceleration occur (scientifically it is due to collision with other particles, which are moving with a different characteristic frequency), resulting in radiation. This radiation includes so-called Bremsstrahlung γ-rays. These γ-rays have been detected by ground-based observatories as reported by many researchers (Chilingarian et al., 2010; Dwyer et al., 2004, 2012). Others have observed with airborne detectors (Dwyer et al., 2015) and yet others with terrestrial γ-ray flashes from space (Fishman et al., 1994). Each event of lightening creates enough energy to trigger photonuclear reactions, which can produce irradiation that cannot be recreated in any event, occurring on earth. These reactions are known to produce neutrons and eventually positrons via β 1 decay of the unstable radioactive isotopes, most notable of which is 13N. This isotope is very unstable with a half-life of 9.965 minutes. This form is generated via the following nuclear reaction: 14

N 1 γ-13 N 1 n;

where γ denotes a photon and n a neutron. This description comes from the work in astrophysics. It is stated that a carbon
nitrogen
oxygen cycle, sequence of thermonuclear reactions that provide most of the energy radiated by the hotter stars, are amenable to mass
energy equivalence, E 5 mc2. The German American physicist Hans Bethe first described the process in 1938 (Wark, 2007). The reactions are as follows: a 12C nucleus captures a hydrogen nucleus 1H (a proton) to form a nucleus of 13N, a gamma ray (γ ) is emitted in the process. The 13N nucleus emits a positive electron (positron, e1) and becomes 13C. This nucleus captures another proton, becomes 14N, and emits another gamma ray. The 14N captures a proton to form oxygen-15O; the resulting nucleus ejects a positron as above and is thereby transformed to 15N. Eventually, the 15 N nucleus captures a fast-moving proton and breaks down into a 12C nucleus plus a helium nucleus (α particles) of mass 4 (4He). In New Science symbols, they are written as follows: 12

C 1 1 H-13 N 1 γ

13

N-13 C 1 e1

13

C 1 1 H-14 N 1 γ

14

N 1 1 H-15 O 1 γ

15

O-15 N 1 e1

15

N 1 1 H-12 C 1 4 He 1 γ

Note that this notation is not scientific as at no time such isolated reaction actually takes place. None of the components actually exists in that form. In addition, the notion of reducing matter into “photon,” with zero mass or neutron with zero charge is absurd and contrary to conservation of mass. In reality, the following transformation is in place: High

Air 1 Solar material 1 Water
! Plasma state Temperature

2

It is assumed to be electrons, by Islam (2014)’s Galaxy model eliminates such spurious denomination. Instead, we use the term “particles,” which include all invisible components of matter and energy.

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FIGURE 4.56 Depiction of thermonuclear reactions.

Fig. 4.56 shows the depiction of the thermonuclear reaction that take place during and after lightening. The subscript BL stands for “before lightening” whereas the subscript AL means “after lightening.” Here the words electron and positron are used but it can mean any “particle” within mass or energy systems. As such, the two yin
yangs on the left would represent collection of two entities that have different charges, as shown with the characteristic spinning direction.3 Two different directions of the taijitu symbols represent characteristic frequency of every “particle.” Such characteristic frequency represents both its monist (wuji) and its dualist (yin and yang) aspects of the entity. Due to the surge in temperature, surrounding area goes through thermonuclear changes. As a result the taijitu structure of the right emerges. The wiggly arrow represents the emergence of an entirely different characteristic frequency from their prelightening counterparts. As a result of this “collision” smaller particles, leave the area. These smaller particles are called “rays” in New Science vocabulary (in this example, “photons,” denoted by γ). Irrespective of the scientific merit of the electron positron conundrum, scientists maintained the dialog of electron colliding with positron leading to annihilation, which emits photon. Islam (2014) described this configuration in terms of two galaxies with opposite characteristic frequencies “colliding” to create a 3

This “spinning” is not fictitious like electron charge, it is rather characteristic frequency of a phenomenal particle.

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tumult, which may eventually turn into a “titanic tumult”. With the depiction of Fig. 4.56, the fictitious notions of emission of γ rays and electron-positron annihilation become moot. The following description of lightening summarizes the nature of lightening and its role in initiating nitrogen fixation (from Betz et al., 2009). The existence of a cloud is essential to triggering lightening. Although, clouds are associated with the lower part of the atmosphere, this cloud is actually one of four types that exist in nature. Of course, clouds form when humid air cools enough for water vapor to condense into droplets or ice crystals. Normally, water vapor can only condense onto condensation nuclei—tiny particles that serve as kernels around which drops can form. The altitude at which this happens depends on the humidity and the rate at which temperature drops with elevation. In low temperature and low concentration of air, as experienced in various levels of the atmosphere, the behavior of water is not straight forward. It is further complicated by the solar radiation, which causes the change of state in water in a way not understood with New Science. Fig. 4.57 shows various layers of the atmosphere. The entire atmospheric layer is some 120 km think, but this thickness is very small compared to the diameter of the earth (12,742 km). Within the atmosphere, very complex chemical, thermodynamic, and fluid dynamics effects occur. This has tremendous implication on the electric properties of matter. Of significance is the fact that the composition of the atmosphere is fluid and constantly changing in time and space due to continuity of matter and the constant solar irradiation. The sun being the primary energy source, the Earth is constantly heated through solar irradiation. Because of the solid and liquid nature of the earth, it retains heat FIGURE 4.57 Temperature profile of the atmospheric layer (data from NASA).

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and the atmosphere near the surface of the Earth heats up. The heated air is then diffused and convected up with constant thermochemical changes through the atmosphere. This process leads to the highest temperature near the surface of the Earth. As the altitude decreases the practically linear decrease takes place throughout the troposphere. This is the region where the mixing of air is most intense (due to the rotation of the Earth). The air density depends on both the temperature and the pressure (along with others that are not accounted for in the equation of state). The linear relationship between temperature and altitude is captured through the following equation: T 5 15:04 2 :00649 h

(4.21)

where, T is in C and h in meter. For the same region, the expression for pressure, p is given as follows:

5:256 (4.22) p 5 101:29 ðT1273:1Þ=288:08 where the temperature is given in C and pressure in kPa, and h is the altitude in meters. Of course, the above expression assumes that the pressure and temperature change only with altitude. Although this correlation was developed in the early 1960s, it still is in use today. As can be seen from Fig. 4.59, the troposphere runs from the surface of the Earth to 11,000 m. The lower stratosphere runs from 11,000 to 25,000 m. In the lower stratosphere the temperature is constant and the pressure decreases exponentially. The metric units curve fits for the lower stratosphere are: T 5 2 56:46

(4.23)

p 5 22:65 eð1:732:000157hÞ

(4.24)

The lower stratosphere zone acts as an isothermal blanket, rendering the inside of the atmospheric system into an adiabatic chamber. Such behavior is a sign of equilibrium that is reached within the planetary system. This isotherm zone is surrounded by the upper stratosphere zone, which is above 25,000 m. In the upper stratosphere the temperature increases slightly and the pressure decreases exponentially. The reason for the increase in temperature is that the direct heat source for the stratosphere is the Sun. This is the layer, where ozone molecules absorb solar radiation, thus heating the stratosphere. Ozone molecules are formed due to interactions with UV emitted from solar irradiation. Note that this UV source is the sun and therefore, the resulting ozone is not the same as the one artificially made in an commercial setting. New Science has disconnected UV from its source, but a truly scientific approach must consider the difference by maintaining the continuity between mass and energy (Islam et al., 2015). As we have seen in earlier discussion, everything in nature is in a state of motion, including time itself. However, instead of realizing this obviously spurious premise, New Science offers the following explanation (Islam, 2014): “If you take away energy from an atom, you do so by lowering the energy level of its electrons, which emits a photon corresponding to the energy gab between the electron bands. Keep doing that until the electron is absorbed by the nucleus, and converts a proton to a neutron. Now you need to extract energy from the nucleus. How are you going to do that? How are you going to shield the resulting neutron from the influence of the rest of the universe, including radio waves, that penetrate everything?”

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Another explanation attempts to justify discontinuity between mass and energy, by saying, “All matter has energy, unless it is at absolute zero temperature, true. But that amount of energy is tiny compared to the energy you could get if the matter were totally converted to energy via Einstein’s famous equation, E 5 mc2. But there is no way for that to happen unless you are dealing with antimatter. Even the sun converts only a tiny percentage of the matter to energy, but that tiny percentage (because of the c2 term) produces a lot of energy.” (Quoted by Islam, 2014). In this, the notion of “antimatter” is invoked. Instead, the energy problem (hence UV and other waves), can be properly handled by stating that natural light or heat or any wave is a direct function of radiation from a system. Such “radiation” is inherent to any matter as long as the spurious assumption of rigid body (as in atom or any other subatomic particle) is not invoked. This radiation is continuous and accounts for change in mass within a system. In this, there is no difference between heat generation and light generation, nor there is any difference in radiation of different types of “radiation” (such as X-ray, gamma ray, visual light, and infrared) other than they are of various frequencies. This can be reconciled with New Science for the limiting cases that say that there is an exponential relationship between reactants and products (Arrhenius equation) through the time function. Such relationship is continuous in time and space. For instance, as long as the assumption of continuity is valid, any substance is going to react with the media. The term “reaction” here implies formation of a new system that will have components of the reactants. This reaction has been explained by Khan et al. (2008) as a collection of snowflakes to form avalanche. Islam et al. (2014) developed similar theory that also accounts for energy interactions and eliminates separate balance equations for mass and energy. This theory considers energy or mass transfer (chemical reaction or phase change) as merger of two galaxies. Before merger, the two galaxies have different sets of characteristic frequencies. However, after merger, a new galaxy is formed with an entirely new set of characteristic frequencies. Such phenomena is well understood in the context of cosmic physics. Picture 4.2 shows NASA picture of two galaxies that are in a collision course. Cowen (2012) reported the following explanation: “Four billion years from now, the Milky Way, as seen from Earth in this illustration, would be warped by a collision with the Andromeda galaxy. It’s a definite hit. The Andromeda galaxy will collide with the Milky Way about 4 billion years from now, astronomers announced today. Although the sun and other stars will remain intact, the titanic tumult is likely to shove the Solar System to the outskirts of the merged galaxies.”

Such collision does not involve merger of two suns or any planets or moons. It simply means reorientation of the stars and planets within a new family. Note how conservation of mass is strictly maintained as long as an artificial boundary is not imposed. In New Science, such artificial boundary is imposed by confining a system within a boundary and imposing “no leak” boundary conditions. Similarly, adiabatic conditions are imposed after creating artificial heat barriers. Islam (2014) introduced the galaxy model, physical or chemical changes can both be adequately described as change in overall characteristic frequency. So, how does heat or mass gets released or absorbed? As stated above, “the titanic tumult” would cause the stars to be “shoved” toward the outskirt of the newly formed galaxy. In case, they are

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indeed placed around the outskirt, this would translate into excess heat near the boundary. However, if those stars are “shoved” inside the new giant galaxy, for an outsider, it would appear to be a cooling process, hence, endothermic reaction. In this context, the “titanic tumult” is equivalent to the “spark” that lights up a flame or starts a chain reaction. It is also equivalent of onset of life or death as well as “big bang” in the universal sense. Even though these terms have been naturalized in New science vocabulary, they do not bear scientific meaning. Islam et al. (2012, 2014) recognized them to be unknown and unexplainable phenomena that cause onset of a phase change. They can be affected by heat, light, pressure that are direct results of changes within the confine of a certain system. Source of heat is associated to “collisions” as represented above in the context of galaxies, be it in subatomic level (known as chemical reactions), in combustion within a flame, or in giant scale (such as solar radiation). For our system of interest, that is, the earth, our primary source of heat is the sun that radiates mass in various wavelengths. New Science recognizes “the solar constant” as the amount of power that the sun deposits per unit area that is directly exposed to sunlight. The solar constant is equal to approximately 1368 W/m2 at a distance of one astronomical unit (AU) from the sun (that is, on or near earth). Sunlight at the top of earth’s atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light. In another word, the heat source is inherently linked to light source. As discussed in previous sections, this transition between different forms of energy is continuous and should be considered to be part of the same phenomenon characterized here as “dynamic nature of everything in creation.” These are not “mass-less” photons or “energy-less” waves, they are actually part of mass transfer that originates from radiation of the sun Before solar emissions enter the atmosphere of the earth, nearly one-third of the irradiative material are deflected through filtering actions of the atmospheric particles. How does it occur? It is similar to the same process described above as galactic collision. During this process, the composition of the atmospheric layer changes continuously and “new galaxies” form continuously in the “tumult” mode, while some of the material are deflected outside the atmosphere and the rest penetrating the atmosphere to trigger similar “tumult” events through various layers of the atmosphere. These atmospheric layers are such that all the layers act similar to a stacked up filtering system. It is well known that the sun is the primary source of energy for the earth. However, all scientific analyses involving organic matter ignore the composition of the sun. It is because, New Science does not offer continuation between mass and energy, as if when light radiates from the sun and provides energy to the earth, no mass transfer takes place. This is when a photosynthesis reaction that require the presence of sunlight cannot be analyzed properly. From that point on, all contributions of the sun are not factored in in any analysis. Table 4.19 Shows the composition of the sun. While this list is not comprehensive, it is perceivable that all elements present on earth will also be present in the sun. This is because otherwise an equilibrium composition of earth would not be maintained. All vegetation on earth starts off with solar energy. If the artificial barrier between energy and mass is removed, the immediate consequence of solar irradiation would be manifested in the light spectrum of sunlight. Interestingly, the most abundant section of the solar light spectrum is the section that produces visible light (wavelength range of 400
750 nm). Table 4.20 shows the wavelength of various visible colors.

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TABLE 4.19 Sun composition (Chaisson and McMillan, 1997). Element

Abundance (percentage of total number of atoms)

Abundance (percentage of total mass)

Hydrogen

91.2

71.0

Helium

8.7

27.1

Oxygen

0.078

0.97

Carbon

0.043

0.40

Nitrogen

0.0088

0.096

Silicon

0.0045

0.099

Magnesium

0.0038

0.076

Neon

0.0035

0.058

Iron

0.0030

0.14

Sulfur

0.0015

0.040

TABLE 4.20 Wavelengths of various visible colors. Wavelength (nm)

Color

,400

Ultraviolet (invisible)

400
450

Violet

450
490

Blue

490
560

Green

560
590

Yellow

590
630

Orange

630
670

Bright red

670
750

Dark red

.750

Infrared (invisible)

From Islam (2014).

All wavelengths beyond these wavelengths of visible light are inherently harmful. The premise that nature is perfect leads to the conclusion that other rays are also necessary but their intensity must be very low, in line with the corresponding low intensities. Table 4.21 shows the wavelengths of all the known waves. It is important to note here that wavelengths themselves do not contain any information about the quality of these rays. Whenever, it is from artificial source, these rays act like a cancer within the overall system. So, when UV from solar irradiation breaks the oxygen molecules into its atomic form, which then combine with residual oxygen molecules to form ozone, the resulting ozone is of different quality than Ozone that is produced in a laboratory. The process is continuous

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299

Wavelengths of known waves.

Type of rays

Wavelength

Gamma ray

1022
1026 nm

X-ray

10
1021 nm

Ultraviolet

10
400 nm

Visible (by humans) light

Violet

400
450 nm

Blue

450
490 nm

Green

490
560 nm

Yellow

560
590 nm

Orange

590
630 nm

Bright red

630
670 nm

Dark red

670
750 nm

Infrared

800
1000 nm

Microwave

0.001
0.3 m

Radio wave

1 m
1 km

From Islam et al. (2015).

and stable as ozone molecules themselves break down under further irradiation. As a result much of the UV rays get absorbed in the Ozone layer. The overall balance in the system is disturbed in presence of artificial chemicals such chlorine containing aerosol. These chlorine molecules can interfere with the continuous forming and breaking process. This fact is well known but what is not known is the fact that UV emitted from the Sun is in sync with nature and therefore is fundamentally different from the UV that is generated with electrical excitement of heavy metal vapor (Islam et al., 2015). This is of crucial importance in the discussion of lightening—a natural phenomenon that triggers many events, consequential to the ecosystem. The next layer is mesosphere. In this layer, the temperature versus altitude trend reverses, and the temperature drops quickly with higher altitude. The coldest temperatures in Earth’s atmosphere, approximately 290 C, are found near the top of this layer. The decrease in temperature is attributed to the decrease in absorption of solar radiation by the rarefied atmosphere and increasing cooling by CO2 radiative emission. In this context, Fig. 4.58 reveals the nature of radiance for various greenhouse gases. Note that New Science makes no room for distinguishing natural source from artificial sources. As a consequence, natural chemicals are lumped together with synthetic one and are actually shown to be more destructive than natural ones. This fundamental misunderstanding of science of nature leads to seeking out spurious solutions, such as spraying of aerosol in the atmosphere. For instance, spraying sulfate particulates into the lower stratosphere, around 20 km from the Earth surface is actively being sought to combat global warming (Smith and Wagner, 2018).

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FIGURE 4.58 Spectrum of the greenhouse radiation measured at the surface. Source: Modified from Evans and Puckrin (2006).

The boundary between the mesosphere and the thermosphere above it is called the mesopause. In this boundary the thermal gradient reverses. The mesosphere is directly above the stratosphere and below the thermosphere. It extends from about 50 to 85 km above the Earth surface. This zone is the most unknown among all the layers of the atmosphere. This is because this area is too high for weather balloons and too low for satellites. It is, however, known that mesosphere contains less than 0.1% of air. This is expected as the outer layer approaches the outer space, which presumably contains hydrogen and helium (in their plasma state), along with electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays.4 Once again, the terms “radiation,” magnetic fields, etc. are not scientific and do not include any information regarding the source. This deficiency can be corrected by using the galaxy model that Islam (2014) presented. It is known that most meteors vaporize in the mesosphere. Some material from meteors lingers in the mesosphere, causing this layer to have a relatively high concentration of iron and other metal atoms, which occur in a form not tractable with New Science. For this reason, the galaxy model describes all forms of energy in terms of cumulative mass, which includes all “particles” within a matter. It is in the mesosphere that high altitude clouds called “noctilucent clouds” or “polar mesospheric clouds” form near the poles. These peculiar clouds form much, much higher up than other types of clouds and are unique to the polar region. The mesosphere, similar to the stratosphere, is much drier than the moist troposphere. However, the temperature being much lower than lower layers, the formation of clouds is anticipated. At this low 4

This emerges from the Big Bang theory that stipulates that the baseline temperature of 2.7 K. It is subsequently deduced that the plasma between galaxies accounts for about half of the known matter in the universe with a density value less than one hydrogen atom per cubic meter and a temperature of millions of kelvins (Gupta et al., 2010).

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temperature, electric charges can accumulate and be discharged in the form of “lightening,” called “sprites” and “ELVES.” However, the formation of clouds in mesosphere and “sprites” are not well understood and has puzzled scientists (Lyons et al., 2008). The total charge moment change required to initiate sprites is believed to be at least approximately 500 C km (Lyons et al., 2009). Also, the great majority of sprite initiations are delayed after the return stroke by much more than the 2 Ms time period used in typical modeling. Such occurrence can be explained by the fact that the onset of lightening is a function of numerous factors, not accounted for in today’s atmospheric science of physics. In fact, the galaxy model shows that there are numerous factors that play a role and a single event can trigger great changes. The stratosphere and mesosphere together are sometimes referred to as the middle atmosphere. At the mesopause (the top of the mesosphere) and below, gases made of different types of atoms and molecules are thoroughly mixed together by turbulence in the atmosphere. Above the mesosphere, in the thermosphere and beyond, gas particles collide so infrequently that the gases become somewhat separated based on the types of chemical elements they contain. The presence of tiny amount of metals, for instance, from meteors can also trigger a chaotic motion due to the difference in chemical composition within an environment, where oxygen (and also of water) concentration is extremely low. It is also true in the presence of any artificial chemical at any concentration as it acts as a trigger point for chaotic motion. Similar triggering can occur in presence of various types of waves in the atmosphere influence the mesosphere. These waves carry energy from the troposphere and the stratosphere upward into the mesosphere, driving most of its global circulation. Similarly, solar radiation penetrates this region relatively in its original form, thereby causing changes that are little known because those events do not take place in lower strata of the atmosphere. The thermosphere is a layer with auroras. This layer sees intensive ionic activities. The thermosphere is the layer in the Earth’s atmosphere directly above the mesosphere and below the exosphere. Within this layer of the atmosphere, ultraviolet radiation causes photoionization/photodissociation of molecules, creating ions in the ionosphere. In true scientific terms, it means any bonding between “particles” inherent to oxygen, nitrogen, and others is obscured in favor of random movements, making them act like a radioactive material. The thermosphere begins at about 80 km above sea level. Similar to Stratosphere, the temperature gradient reverses in Thermospheric, as temperatures increase with altitude. Such rise in temperature is due to absorption of solar radiation. Temperatures can rise to 2500 C during the day. Radiation causes the atmosphere particles in this layer to become electrically charged, as expected due to the presence of extremely high temperature and intense solar irradiation. The dynamics of the thermosphere are dominated by atmospheric tides, which are driven by the very significant diurnal heating. As expected, this process is dependent on the season and is associated with cyclic events. It has been observed that coldest temperatures generally occur at, or up to about 18 days after, the time at which the equator-ward winds of the summer-time are at their strongest (Islam, 2020). The mean zonal winds are eastward throughout much of the year but do display some westward flow in winter and around the equinoxes. The 16- and 5-day planetary waves reach large amplitudes in winter and are present in summer. The planetary-waves are evident in both wind and temperature measurements and the largest amplitudes in wind and temperature generally occur simultaneously.

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In contrast to solar extreme UV (XUV) radiation, magnetospheric disturbances, indicated on the ground by geomagnetic variations, show an unpredictable impulsive character, from short periodic disturbances of the order of hours to long-standing giant storms of several days’ duration. Important for the development of an ionospheric storm is the increase of the ratio N2/O during a thermospheric storm at middle and higher latitude. An increase of N2 increases the loss process of the ionospheric plasma and causes therefore a decrease of the electron density within the ionospheric F-layer (negative ionospheric storm) (Pro¨lss, 2011). Today’s understanding of the typical vertical charge distribution within different types of mature convection is depicted in Fig. 4.59. This conceptual model shows common features from analysis of 49 E soundings through three types of convection frequently studied with modern balloon instruments: isolated supercells and multicellular squall lines of mesoscale convective systems (MCSs) over the U.S. Great Plains, and small single- and multi-cell storms over the mountains of central New Mexico. The four main charge regions are identified in Fig. 4.61 (with red 1 for positive charge, blue—for negative charge). Representative electric field (E) and electrostatic potential (V) profiles in the nonupdraft (left) and updraft (right) of the convective region are also shown. Schematic representations of an intracloud flash (in green) and a cloud-to-ground flash (in purple) are shown as they might appear in lightning. Outside the updrafts, but still within a storm’s convective region, there are typically at least six charge regions, alternating in polarity from lowest to highest, and the uppermost region has negative charge. While they are generally more complex than updraft soundings, nonupdraft soundings also tend to exhibit more variability from one storm to another, or, as recently shown by Weiss et al. (2008) even from one sounding to the next within a storm. One key feature of the thunderstorm electrical structure is that the charge regions tend to be horizontally stratified: the vertical thickness of each charge region is less (often much less) than its horizontal dimension. Among

FIGURE 4.59 Conceptual model of the electrical structure in mature, mid-latitude convection. Source: From Stolzenburg and Marshall (2008).

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the three types of convection studied by Stolzenburg et al. (1998), the heights and temperatures of the basic four charge regions differed, with temperatures ranging from 27 to 222C. Due to thermal changes, the compositional changes follow, triggering a conductive pathway that could be followed by a lightening strike. Low-level clouds lie below 6500 feet (2000 m) and are referred to as stratus clouds. They’re often dense, dark, and rainy (or snowy) though they can also be cottony white clumps interspersed with blue sky. Due to the difference in temperature alone, potential difference in electric charge sets in. The most dramatic types of clouds are cumulus and cumulonimbus, or thunderheads. Rather than spreading out in bands at a fairly narrow range of elevations, as in other clouds, they rise to dramatic heights. Cumulus clouds are fair-weather clouds. When they get big enough to produce thunderstorms, they are called cumulonimbus. These clouds are formed by upwelling plumes of hot air, which produce visible turbulence on their upper surfaces, making them look as though they are boiling. The formation of cloud itself is triggered by the rise of hot air—something that happens as the ground temperature rises. As warm air rises, the ambient temperature becoming cooler, the water vapor cools to form clouds. How lightening is onset is still a mystery. However, the temperature within lightening can reach up to 27,000 C, some six times higher than the surface of the sun. This temperature itself would create a plasma state of matter. Although New Science considers that plasmas have no fixed shape or volume, and are less dense than solids or liquids, but are a collection of protons that are stripped off electrons, such assumption is not necessary. As early as a century ago, Nikola Tesla objected to this depiction of matter in general and electricity in particular. Similar to what Islam (2014) argued, Tesla disagreed with the theory of atoms being composed of smaller subatomic particles, stating there was no such thing as an electron creating an electric charge. He believed that if electrons existed at all, they were some fourth state of matter or “sub-atom” that could exist only in an experimental vacuum and that they had nothing to do with electricity (O’Neill, 1944). Although Tesla’s belief that Tesla atoms are immutable5 is illogical and false, his other belief that there is a continuous phase (which was known as ether at the time) is not illogical (Seifer, 2016). In fact, Islam (2014) compiled modern data to establish that there is a continuous phase, which is ubiquitous. Also correct is the notion that there is no such matter as electron that is uniquely responsible for electricity. Furthermore, it is New Science that is illogical to subscribe to the notion that electricity propagates like mass as envisioned by Maxwell and adopted by Einstein, who formulated the equation E 5 mc2, based on Maxwell’s equation. Tesla was also correct in pointing out that the notion of “curving” space, essentially meaning that the time can be manipulated, is absurd. He correctly paralleled such notion with attributing material property to God (O’Neills, 1944). This notion has been refuted thoroughly by Islam (2014) (Picture 4.6). Another characteristic of plasmas is that they can be held in place by magnetic fields. In scientific term, it means, plasma is not amenable to New Science, which focuses on the tangible features of matter after disconnecting the transition between mass and energy.

5

This assumption comes from Ancient Greek, who introduced the word “atom” (ατoμασ), which literally means “indestructible” (Khan and Islam, 2016).

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PICTURE 4.6 Plasma state in the surface of the sun. Credit NASA.

While the full nature of lightening remains elusive, there are certain features for which there is a consensus today. It is agreed that the main charging area in a thunderstorm occurs in the central part of the storm where air is moving upward rapidly (updraft, see Fig. 4.61) and temperatures range from 215 C to 225 C. The required strength of the updraft is $ 7 m/s (Heymsfield et al., 2009). At that place, the combination of temperature and rapid upward air movement produces a mixture of super-cooled cloud droplets (small water droplets below freezing), small ice crystals, and instantly formed hails. As the updraft carries the super-cooled cloud droplets and very small ice crystals upward, at the same time, the graupel (soft hail or snow pellets), which is considerably larger and denser, tends to fall or be suspended in the rising air (NOAA, 2019). When the rising ice crystals collide with falling or stagnant graupel, creating “spark,” which is described in New Science through the mixing of positively (rising) and negatively (falling) the ice crystals become positively charged and the graupel becomes negatively charged. In the Galaxy model, this is equivalent to “titanic tumult”, which leads to the onset of major events, such as lightening. As explained earlier, this is the advantage of the Galaxy model, which was first introduced by Islam (2014). The updraft carries the “positively charged” ice crystals toward the top of the storm cloud. The larger and denser graupel is either suspended in the middle of the thunderstorm cloud or falls toward the lower part of the storm (NOAA, 2019). The “spark,” no matter how small, acts as a trigger point for more “sparks,” which force the upper part of the thunderstorm cloud to spread out horizontally some distance from thunderstorm cloud base. This part of the thunderstorm cloud is called the “anvil” (Fig. 4.61). In addition, even near the bottom of the cloud there can be built of “sparks” due to the mixing of precipitation and warmer temperatures

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(Fu¨llekrug and Rycroft, 2006). Lightning primarily occurs when warm air is mixed with colder air masses, resulting in atmospheric disturbances necessary for polarizing the atmosphere. However, it can also occur during dust storms, forest fires, tornadoes, volcanic eruptions, and even in the cold of winter, where the lightning is known as thundersnow (Genareau et al., 2017). Hurricanes typically generate some lightning, mainly in the rainbands as much as 160 km from the center. Lightning is initiated when sufficient events of “sparks” have taken place and the momentum for a larger event has been created. This is equivalent to the gathering of an electric field with large magnitude. It is mentioned earlier that collisions between rising and falling “particles” at different temperatures triggers “sparks.” When these “sparks” are at sync and gain momentum when a highly conductive channel is opened. Such channel can be created within a highly chaotic system—the kind that prevails within the atmospheric layers. Fig. 4.60 shows time-height plot of kinematic, electrical, and cloud microphysical parameters in a northern Alabama thunderstorm cell on July 20, 1986 (Brown et al., 2002). The solid curves are the maximum radar reflectivity values (dBZ) at each height for each

FIGURE 4.60 Time-height plot of kinematic, electrical, and cloud microphysical parameters in a northern Alabama thunderstorm cell on July 20, 1986. The solid curves are the maximum radar reflectivity values (dBZ) at each height for each volume scan during most of the cell’s lifetime. The longer dashed curve encompasses the height interval of hail (based on dual-polarimetric signatures) and shows the region of mid-altitude hail growth and subsequent descent (Brown et al., 2002).

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volume scan during most of the cell’s lifetime. The longer dashed curve encompasses the height interval of hail and shows the region of mid-altitude hail growth and subsequent descent. A microburst occurred at the surface when the hail and heavy rain reached the ground. Fig. 4.60 also shows the occurrence of microbursts at the surface when the hail and heavy rain reached the ground. The contours in Fig. 4.60 represents the temporal evolution of maximum reflectivity values as a function of height for a series of three-dimensional volume scans within the storm. As illustrated in Fig. 4.60, the first cloud flash in the growing cell occurred a few minutes after hail/graupel had started to form at middle altitudes (the longer dashed curve encompasses the region of hail growth and subsequent descent). The presence of a strong updraft and graupel at middle altitudes would be expected to be conducive to noninductive charging of the hydro-meteors. As the top reflectivity contour (20 dBZ) reached its greatest height, the updraft was beginning to weaken. The first cloud-to-ground lightning flash in Fig. 4.60 followed within about 5 minutes of the first cloud flash. Ground flashes were relatively infrequent, but ground flash rates peaked at approximately the same time as cloud flash rates. The period of CG activity spanned the period in which the hail/graupel region descended from middle altitudes toward the ground. Melting graupel and hail contributed negative buoyancy to the descending air, which becomes heavier and a microburst formed as the descending region reached the ground. Shortly after pea-size hail, graupel, and heavy rainreached the surface, ground flash activity ceased, but cloud flash activity continued for another 5
10 minutes in the collapsing cell. Brown et al. (2002) reported various stages undergone by each cell: 1. Growing (Cumulus) Stage—the growing cell consists entirely of vertically developing and strengthening updraft air. 2. Mature Stage—the main rainy downdraft exists in a portion of the middle and lower regions of the cell, while updraft still occupies the full depth of the remaining portion of the cell. 3. Dissipating Stage—weak descending air occupies the entire middle and lower regions of the cell with nondescript vertical motion in the upper region; this stage ends with the cessation of light rain at the surface. A typical cloud-to-ground lightning flash culminates in the formation of an electrically conducting plasma channel through the air in excess of 5 km tall, from within the cloud to the ground’s surface. The actual discharge is the final stage of a very complex process. The mixture is thought to produce electrification by the noninductive graupel-ice mechanism. However, other mechanisms also contribute, making the process dependent on parameters that are subject matters of broader research. In this process, the polarity of charge transfer appears to be a function of the cloud liquid water content and the ambient temperature. At its peak, a typical thunderstorm produces three or more strikes to the Earth per minute (Uman, 1986). Fig. 4.61 shows the world map of the frequency of lightening. On Earth, the lightning frequency is approximately 44 ( 6 5) times per second, or nearly 1.4 billion flashes per year and the average duration is 0.2 seconds made up from a number of much shorter flashes (strokes) of around 60 to 70 microseconds (NASA, 2022).

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FIGURE 4.61 World map of the frequency of lightening. Source: From NASA (2019).

The high lightning areas are on land located in the tropics. In this region, atmospheric convection is the greatest. Areas with almost no lightning are the Arctic and Antarctic, closely followed by the oceans which have only 0.1
1 strikes/km2/yr. The lightning flash rate averaged over the Earth for intra-cloud (IC) 1 cloud-to-cloud (CC) to cloud-to-ground (CG) is in the ratio: (IC 1 CC):CG 5 3:1. The base of the negative region in a cloud is normally at roughly the elevation where freezing occurs. The closer this region is to the ground, the more likely cloud-to-ground strikes are. In the tropics, where the freeze zone is higher, the (IC 1 CC):CG ratio is about 9:1. In Norway, at latitude 60 N, where the freezing elevation is lower, the (IC 1 CC):CG ratio is about 1:1 (Uman, 1986). About 70% of lightning occurs on land in the Tropics, where the majority of thunderstorms occur. The North and South Poles and the areas over the oceans have the fewest lightning strikes.

4.10 Nitrogen cycle: part of the water/nitrogen duality Nitrogen plays a crucial role in transitioning from inorganic to organic molecules. In nature, nitrogen cycle is controlled through activities triggered by lightening. This cycle is molested through introduction of electricity (artificial version of lightening) during industrial manufacturing of ammonia and other chemicals that form an integral part of the chemical engineering industry. Nitrogen in many ways is the equivalent of water, in the sense that it is ubiquitous in the atmosphere and as such in every living body. In fact, nitrogen is integral part of the biosignature that is sought in search of life in outer space. On an elemental basis, nitrogen’s yin
yang pair is oxygen. Table 4.22 lists the contrasting and unifying properties of nitrogen and oxygen. The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems.

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TABLE 4.22 Contrasting and unifying characters of oxygen and nitrogen. Nitrogen

Oxygen

Nitrogen has 7 protons

Oxygen has 8 protons

Atomic number of 7

Atomic number of 8

Atomic mass of 14

Atomic mass of 16

78% of the atmosphere

21% of the atmosphere

Under normal conditions, nitrogen is a colorless, odorless, and tasteless gas. Nitrogen belongs to Group 15 (Va) of the periodic table. Other elements of the group are phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and moscovium (Mc).

Nitrogen is present in all living things, including the human body and plants.

Under normal conditions, oxygen is a colorless, odorless, and tasteless gas. Oxygen is a member of the chalcogen group on the periodic table and is a highly reactive nonmetallic element. Other elements of this group are sulfur (S), selenium (Se), tellurium (Te), and the radioactive element polonium (Po). Oxygen is present in all living things, including the human body and plants.

Toxic in high concentration

Toxic at high concentration (e.g., over 50% for humans) 



Liquid nitrogen boils at 2196 C and freezes at 2210 C.

Boils at 2183 C, freezes at 2218.8 C

Ammonia (NH3) is another nitrogen compound commonly used in fertilizers.

Oxygen is flammable We breathe in oxygen.

N is inert(almost) and has a charge of 3 2

O is reactive and has a charge of 2 2

Nitrous oxide is a considerable greenhouse gas and air pollutant. By weight, it has nearly 300 times more impact than carbon dioxide.

CO2 is a greenhouse gas with 300 times less impact than nitrous oxide

Nitroglycerin is a liquid used to create explosives such as dynamite.

Water is the explosion product

Nitric acid (HNO3) is a strong acid often used in the production of fertilizers.

Forms acid, which may be used for both environmental harm and benefit

In plants, much of the nitrogen is used in chlorophyll molecules which are essential for photosynthesis and further growth (Smil, 2000). This is how nitrogen becomes integral part of the life cycle. Nitrogen fixation is required for all forms of life, with nitrogen being essential for the biosynthesis of molecules (nucleotides, amino acids) that create plants, animals and other organisms. Because the conversion of nitrogen can be carried out through both biological and physical processes, it is often difficult to separate the two systems. Scientists have struggled to take evidence and conclude the existence of life. Even then, organic-rich, fine-grained sedimentary rocks, such as black shales, are taken to be important geochemical indicator of biological activities (Playter et al., 2017). While biological productivity and sedimentation rates greatly affect the organic matter content in any rock, mechanisms linking these two processes remain poorly resolved. The most credible theory describes the interactions of clay minerals with the marine planktonic, thus connecting the ocean with the land. Playter et al. (2017) identified that clays settling through

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the water column could influence carbon and trace metal burial in three ways: (1) the interaction of reactive clay surfaces with the bacterial cells increases organic matter deposition via mass increase in a seawater growth medium by several orders of magnitude; (2) reactive bacterial cells become completely encased within a clay shroud, enhancing the preservation potential of this organic matter; and (3) the trace metal content of the biomass buried along with metals sorped to the clay particles contributes to the trace metal concentrations of the black shale precursor sediments. They reported that the chemical composition of ancient, organic-rich, fine-grained deposits are not only archives of ancient seawater composition and redox state, but they also provide a record of the degree of biological activity in the water column through geological time. While mass organic matter deposition can occur in coastal environments, it is recognized that less than 1% of the original organic biomass buried into sediment may ultimately contribute to the sedimentary organic geochemical record. Of that fraction, most is distributed on the continental shelves because (1) there is greater nutrient supply from both land and upwelling to support primary productivity, and (2) residence time for the dead biomass in the water column is shorter there and hence lower potential to be aerobically oxidized in the water column. Nitrogen works with both phytoplankton and bacteria (e.g., cyanobacteria) to stabilize clay minerals—a process so intricate that it remains little understood even today. Some (e.g., Avnimelech et al., 1982) postulated cell preservation through entrapment of microorganisms. Their SEM micrographs revealed that the clay occurred in clusters on the bacteria, while textures that reflected cell morphology were not produced. The nature of clay surrounding bacteria is markedly different from that surrounding diatoms. Diatoms and bacteria are in harmony like the yin
yang duality we discussed earlier. They cooccur in common habitats with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states make continuous cycle between living and dead in nature (Amin et al., 2012). Amin et al. (2012) showed that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. They discuss how bacteria participate in remineralization of exogenous plant and algal material. It has been recently established that marine bacteria can remineralize organic matter from the decomposition of dead diatoms to yield their inorganic constituents, particularly phosphorus, nitrogen, and carbon. Previously, microbial activity vis-a`-vis alga-derived organic matter was thought to be limited to dead diatoms and not to include actively growing cells. Amin et al. (2012) indicated that some bacteria consistently associate with growing diatoms through specific interactions, while other bacteria colonize sinking diatom particles and decompose organic matter therein. It means natural processing is different from artificial processing in both origin and process. This recent discovery is of crucial importance as it unravels the inherent toxic nature of manmade processing techniques. Fig. 4.62 shows the duality of inorganic and organic that results in fundamental units of bacteria and diatoms on the intangible side and light and dust speck on the tangible side. This figure depicts the overall processing involved in nature. Recall that we identified dust specks to be the fundamental unit of mass whereas light (collection of invisible

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FIGURE 4.62

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Yin
Yang behavior in natural elemental “particles.”

particles, none being zero mass) is the intangible counterpart. Dust specks form natural units of clay materials, such as kaolinite and montmorillonite. Studies on the flocculation of kaolinite and certain diatom species showed that the clay particles did not directly attach to the diatom cells but instead they were bound in clusters by the extracellular polysaccharides (EPS). Interestingly, comparison of this work with the micrographs of Synechococcus and kaolinite and montmorillonite aggregates from Amin et al. (2012) suggests that excessive amounts of EPS actually appeared to impede cell encapsulation. This is similar to the work of Chen et al. (2009) who showed that EPS inhibited microbe and clay flocculation. The process is further complicated by the presence of trace metals. Ho et al. (2003) analyzed the cellular content of C, N, P, S, K, Mg, Ca, Sr, Fe, Mn, Zn, Cu, Co, Cd, and Mo in 15 marine eukaryotic phytoplankton species in culture representing the major marine phyla. All the organisms were grown under identical culture conditions, in a medium designed to allow rapid growth while minimizing precipitation of iron hydroxide. The cellular concentrations of all metals, phosphorus, and sulfur were determined by high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) and those of carbon and nitrogen by a carbon
hydrogen
nitrogen analyzer. The cellular quotas (normalized to P) of trace metals and major cations in the biomass varied by a factor of about 20 among species (except for Cd, which varied over two orders of magnitude) compared with factors of 5
10 for major nutrients. Green algae had generally higher C, N, Fe, Zn, and Cu quotas and lower S, K, Ca, Sr, Mn, Co, and Cd quotas than coccolithophores and diatoms. Co and Cd quotas were also lower in diatoms than in coccolithophores. The most intriguing part of this study is in the conclusion that metal uptake is principally governed by genetically encoded trace element physiology of various species. Their observation was

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generally close to the approximate extended Redfield formula given by the average stoichiometry of their model species, given as:   (4.25) C124 N16 P1 S1:3 K1:7 Mg0:56 Ca0:5 1000 Sr5:0 Fe7:5 Zn0:80 Cu0:38 Co0:19 Cd0:21 Mo0:03 This elemental stoichiometry varies between species and is sensitive to changes in the chemistry of seawater, thus providing a basis for changes in phytoplankton and trigger chain of reactions involving the entire ecosystem. This process is continuous and is manifested in characteristic time for the rocks in question. In geological time, every mineral deposit would therefore have a signature of organic material. This process cannot be recreated synthetically without losing the value of the product, even when it is strictly considered to be an inorganic chemical. In the context of this book, this is a crucial point that will help us determine what type of chemicals can be chosen for sustainable applications. The nitrogen cycle includes fixation, ammonification, nitrification, and denitrification. Fig. 4.63 shows the overall picture of the nitrogen cycle. The fixation process involves conversion of nitrogen gas into ammonia, nitrates, nitrites, and others. Unlike oxygen, nitrogen is not directly used by plants and must be processed into a usable form. Lightening alone can trigger the formation of nitrates. The biological fixation takes place through bacteria, whereas industrial fixation uses artificial energy source and catalysts to synthesize ammonia. This important aspect of transition between mass and energy has been overlooked by New Science, other than occasional research publication on instrumentation and property measurement (Giuliani et al., 2018). Nitrogen fixation is one process by which molecular nitrogen is reduced to form ammonia. The fixation process is triggered by lightening. As stated earlier, lightening generates as high as 27,000 C temperature. At this high temperature, there is enough energy for nitrogen and oxygen to be in plasma state, which can trigger many reactions that we are

FIGURE 4.63 The nitrogen cycle.

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not familiar with under terrestrial conditions. Recent research has shown that the gamma rays released by lightning can even set off small-scale nuclear reactions in the atmosphere (Enoto et al., 2017). This natural process can generate different isotopes of nitrogen, oxygen, and carbon. Photonuclear reactions triggered by lightning during a thunderstorm have been directly observed for the first time. In the Galaxy theory of matter, Islam (2014) showed that every temperature change relates to change of state, interlinked with it is the change in irradiation, commonly known as “rays.” One such “ray” is γ ray. At high temperatures, the plasma state is created (Enoto et al., 2017). In the previous section, it is discussed how this plasma state is amenable to changes, which trigger chain reactions, leading to the formation of many natural chemicals that are essential to life. For example, when 14N or 16O are subjected to high temperature along with solar irradiation material (containing collection of solar material), radioactive highly unstable isotopes, such as 13N and 14O, are generated. Through intense irradiation, these materials gradually settle into less unstable form of respective isotopes (Enoto et al., 2017). This is how various forms of nitrogen oxides are formed. In turn, these nitrogen oxides can dissolve in rainwater and form nitrates, which are important for plant growth. Lightning accounts for some naturally occurring reactive nitrogen—worldwide each year, lightning fixes an estimated 3
10 billion kg (or teragram—the usual measurement unit for discussing the global nitrogen cycle). The energy that lightning generates converts oxygen and nitrogen to nitric oxide (NO), which oxidizes to nitrogen dioxide (NO2), then to nitric acid (HNO3). Within days the HNO3 is carried to the ground in rain, snow, hail, or other atmospheric deposition. Islam and Khan (2019) pointed out that despite extraordinary attention to CO2 as a source of climate change and global warming, it is the nitrogen cycle that has been affected the most. They showed that the use of synthetic nitrogen fertilizer is no less devastating than burning fossil fuel, considering the overall impact on the ecosystem. Just like, without CO2, there is no photosynthesis, without nitrogen, there is life activity. Fixed form of nitrogen that is amenable to bonding with carbon, hydrogen, or oxygen, most often as organic nitrogen compounds (such as amino acids), ammonium (NH4), or nitrate (NO3). Animals get their reactive nitrogen from eating plants and other animals somewhere along the food chain. And plants get reactive nitrogen from the soil or water. While nitrogen fixation is triggered by lightening, the actual amount of fixation is far greater for bacteria than with lightening. While lightning accounts for up to 3
10 pg of nitrogen fixed per year, bacteria contribute to 30 times more, ranging from 100 to 300 pg fixed by bacteria (Soumare et al., 2020). Most naturally occurring reactive nitrogen comes from nitrogen fixation by bacteria, including cyanobacteria and specialized bacteria such as those in the genus Rhizobium, which most often live symbiotically in plants such as peas, beans, and alfalfa. During preplastic era, natural cycles used by farmers used to optimize efficacy of the nitrogen cycle by rotating crops with nitrogen-fixing crops such as legumes, or add naturally occurring fertilizers such as manure, guano, and nitrate mineral deposits mined in Chile. This process would naturally produce 15 Tg of synthetic nitrogen chemicals per year (Soumare et al., 2020). Fig. 4.64 shows how nitrogen moving between these temporary resting spots takes diverse forms. The advent of large-scale fertilizer production modifies natural flows of this element enormously, unbalancing the nitrogen cycle in sometimes troubling ways.

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FIGURE 4.64 Of many different kinds exist within the earth’s waters, soil, atmosphere, and biological mantle. Source: From Smil (1997).

As the plastic era inundated the globe, countless technologies emerged to replace natural chemicals with artificial chemicals. Just like, lightening was replaced with electricity soon after electricity was “discovered,” every natural chemical was replaced with synthetic form, which used artificial energy source as well as artificial material, the most important one being artificial fertilizer, which triggered the “Green revolution.” The process in question was developed by German scientists Fritz Haber (who received the Nobel Prize in Chemistry in 1918 for his invention of the Haber
Bosch process, a method used in industry to synthesize ammonia from nitrogen gas and hydrogen gas) and Carl Bosch (who received Nobel Prize in Chemistry in 1931 that he shared with Friedrich Bergius in recognition of their contributions to the invention and development of chemical high-pressure methods). In modern times, the Haber
Bosch process is used to produce about 100 Tg of reactive nitrogen per year worldwide, most of which is used to produce nitrogen fertilizer. Food grown with this fertilizer feeds some 2 billion people (Smil, 1997). The Haber
Bosch process uses artificially purified nitrogen and hydrogen, the former being extracted from air and the later from petroleum (e.g., methane). Recently, the process has become even more toxic by the introduction of hydrogen production through electrolysis of water. This conversion is typically conducted at 15
25 MPa (150
250 atm) and a temperature range of 400 C
500 C, as the gases (nitrogen and hydrogen) are passed

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FIGURE 4.65

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The production of sustainable and unsustainable ammonia.

over four beds of catalysts, which are themselves produced through artificial processes. Fig. 4.65 shows how ammonia that is produced through the Haber
Bosch process is different from the one produced through natural processes. New Science puts these two ammonia as the same as the modern nomenclature does not have any provision to include the history of a chemical. Khan and Islam (2007) designated the top process as unsustainable whereas the bottom process sustainable. Khan and Islam (2012 and 2016) demonstrated that the unsustainable process is perpetually harmful to the environment, whereas the sustainable process is perpetually beneficial. Today, about 30% of the total fixed nitrogen is produced industrially using the Haber
Bosch process (Smith et al., 2020). As stated earlier, this process uses high temperatures and pressures to convert nitrogen gas and a hydrogen source (natural gas or petroleum) into ammonia (Smil, 2004). Even though nitrogen and hydrogen are collected from natural sources (petroleum), the processing is not sustainable as it includes synthetic chemicals. Spanning over a 5-year period, they developed high-pressure and high temperature synthesis of chemicals that were already processed artificially. It was a perfect case of denaturing natural energy and material at the same time. The Haber
Bosch primarily produces synthetic nitrate, a process that has countless industrial applications for making numerous industrial compounds, consumer goods, and commercial products. The Haber
Bosch Process today consumes more than one percent of humanity’s energy production and is responsible for feeding roughly one-third of its population (Smil, 2001). On average, one-half of the nitrogen in a human body comes from synthetically fixed sources, the product of a Haber
Bosch plant. There has been a huge surge in reactive nitrogen production. Human production of reactive nitrogen is currently estimated to be about 170 Tg per year (Fowler et al., 2013). The ratio

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FIGURE

4.66 Longterm variation of the amount of N internationally traded throughout the world. Source: From Lassaletta et al. (2014).

of anthropogenic to natural reactive nitrogen creation is likely to increase with population increases. This surge in reactive nitrogen will create chain reactions through the ecosystem (Lassaletta et al., 2014). They report that the human alteration of the N cycle on a global scale is driven by increased creation of reactive nitrogen due to food and energy production. In 2010, human activities created B210 Tg of reactive nitrogen compared to B58 Tg of reactive N by natural processes (i.e., BNF) on continents (Fowler et al., 2013). Lassaletta et al. (2014) investigated the trends in terms of nitrogen content of all the agricultural products (food, feed, and fibers) traded between all world countries during the prior 50 years. They studied the evolution of the total N embedded in agricultural products that is exchanged between countries at the global scale from 1961 to 2010. Then, they analyzed the evolution of the dependence of each world country on food and feed imports. Finally, they provided one with geographically explicit description of the N fluxes between these regions in 1986 and 2009. Fig. 4.66 Shows variation of N internationally traded throughout the world during 50 years (1960
2010). Traded products have been grouped in categories. Soybeans category includes soybean cake. The category “others” includes all fruits, tubers, and vegetables for human consumption. Lassaletta et al. (2014) pointed out that at the present time, the international trade of food and feed constitutes a significant component of the global N cycle be stock is reallocated to every large world watershed according to the requirement of the current human population. Some countries have opted to export animal products entirely produced inside the nation. This is the case of New Zealand specialized in the export of dried milk. The growth of international food and feed trade amounts to representing globally one-third of total N crop production and represents the role of globalization. The same trend will continue for GMO induced agriculture, for which the ill effects will be quickly distributed across the globe. At all three rates of application, plots fertilized with either ammonium phosphate or ammonium nitrate showed a significant increase in total forage produced over the unfertilized plots. Both fertilizers, even at the lowest rates, almost doubled the forage production over that produced on the unfertilized areas. Plots fertilized with ammonium phosphate showed a linear response in forage production. Scientifically the

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difference column represents the transformation of organic carbon material to nonorganic carbon material. The scientific investigation of Islam et al. (2010) shows that this gain in productivity due to the use of chemical fertilizer is in expense of transformation of environment-friendly carbon to environment-hostile carbon, all of which from this point, one produces CO2 that is no longer acceptable to the ecosystem. However, these calculations cannot be done with conventional scientific analysis because it leaves no room for discerning the pathways of CO2.

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C H A P T E R

5 Transportation of oil and gas 5.1 Introduction The global petroleum reserve continues to grow ever since the drilling of the first set of petroleum wells over 150 years ago. Tremendous advances have been in exploration and production and have helped to locate and recover a supply of oil and natural gas from major reserves across the globe. This development is synchronized with the increase in demand for petroleum products. However, supply and demand are rarely concentrated in the same place. It is true both locally and globally. For instance, China and India, the two most populous countries import 60% and 80%, respectively, of their energy needs are met with imported oils. Fig. 5.1 shows the US production and consumption history of recent decades. This figure highlights the need for crude oil transport. China surpassed the United States in annual gross crude oil imports in 2017, importing 8.4 million barrels per day (b/d) compared with 7.9 million b/d for the United States (Fig. 5.2). China

FIGURE 5.1 Oil production and consumption history.

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FIGURE 5.2 Recent history of US and China import scenario (EIA, 2018). Source: From EIA, 2018, China surpassed the United States as the world’s largest crude oil importer in 2017, December 31, 2018.

had become the world’s largest net importer (imports minus exports) of total petroleum and other liquid fuels in 2013. New refinery capacity and strategic inventory stockpiling combined with declining domestic oil production were the major factors contributing to the recent increase in China’s crude oil imports. In 2017, 56% of China’s crude oil imports came from countries within the Organization of the Petroleum Exporting Countries (OPEC), a decline from the peak of 67% in 2012. More so than other countries, Russia and Brazil increased their market shares of Chinese imports between those years from 9% to 14% and from 2% to 5%, respectively. Russia surpassed Saudi Arabia as China’s largest source of foreign crude oil in 2016, exporting 1.2 million b/d to China in 2017 compared with Saudi Arabia’s 1.0 million b/d. OPEC countries and some non-OPEC countries, including Russia, agreed to reduce crude oil production through the end of 2018, which may have allowed other countries to increase their market shares in China in 2017. All these developments point to the fact that pipelines and tankers are inherent to global energy management. Tankers, railroads, and pipelines are proven, efficient, and economical means of connecting petroleum supply and demand. Supply-end pipelines and railroads carry crude oil from production areas to a loading terminal at a port. Tankers then carry the crude oil directly to demandside pipelines that connect to the refineries that convert the raw material into useful products. Crude oil moves from wellhead to refinery using barges, tankers, overland, pipelines, trucks, and railroads. Natural gas is transported by pipelines and liquefied natural gas (LNG) tankers. Barges are primarily used on rivers and canals. They require less infrastructure than pipelines but are more costly, transport much less volume, and take more time to load. Historically, railroads were the primary means of petroleum transportation. Today, railroads have to compete with railroads and are considered to be more expensive than pipelines. However, the economics changes somehow for new pipelines in an area where a railroad infrastructure already exists.

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The increasing demand for oil has led to deeper drilling, with larger drilling rigs located further offshore, which has justified the building of larger and more powerful tugs and larger barges. In general, the crude oil pipeline network has three different types of pipelines: 1. Gathering pipelines move crude oil from the wellhead to storage and on to upgraders or refineries. 2. Feeder pipelines transport crude oil from storage tanks and processing facilities to transmission pipelines. 3. Transmission pipelines transport crude oil to refining markets, often across provincial or international boundaries. Fig. 5.3 provides an outline of the crude oil pipeline system from the point of production, through processing, and transportation on feeder and transmission pipelines and ultimately to points of consumption (refineries) or exports (via rail or marine tanker). Crude oil markets are complex, and different pipeline types can feed into different kinds of facilities. Also, storage and processing facilities can be located anywhere throughout the system to facilitate operations or increase efficiency. If a pipeline crosses provincial or international boundaries, it is regulated by the Canadian Energy Regulator (CER) in Canada. This report focuses on transmission pipelines because these are generally the ones crossing provincial or international boundaries. Typically, if a pipeline is contained within a province, it is under the jurisdiction of a provincial regulator unless deemed a federal undertaking. Oil and natural gas are the most used energies in the world, contributing to 57.5% of global primary energy consumption (Dudley, 2019). Pipelines are critical infrastructure for the transportation of oil and natural gas, connecting producing areas to refineries, chemical plants, home consumers, and business needs (Shaikh et al., 2017). In the United States, there are more than 190,000 miles of liquid petroleum pipelines and over 2.4 million miles of natural gas pipelines (including the distribution lines that serve homes, offices, and businesses). This constitutes the largest pipeline network in the world. Pipelines can refer to gathering systems (wellhead to processing facilities), transmission lines (supply areas to markets), or distribution pipelines (most commonly to transport

FIGURE 5.3 Crude oil pipeline system overview.

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natural gas to medium or small consumer units). Pipelines play a very critical role in the transportation process because most of the oil moves through pipelines for at least part of the route. After the crude oil is separated from natural gas, pipelines transport the oil to another carrier or directly to a refinery. Petroleum products then travel from the refinery to market by tanker, truck, railroad tank car, or pipeline. As natural gas production grows in the United States, demand for new pipeline construction has been increasing. The United States has about 300,000 miles of natural gas transmission pipelines. Strategic planning involves determining the shortest and most economical routes where pipelines are built, the number of pumping stations and natural gas compression stations along the line, and terminal storage facilities so that oil from almost any field can be shipped to any refinery on demand. Offshore pipelines carry more risk for leaks and environmental impact than onshore pipelines, but technological advancements in pipeline material and monitoring systems have improved pipeline safety and efficiency. Standards exist for safety in the design and construction of pipelines and are published by organizations such as the International Organization for Standardization (ISO) and the American Petroleum Institute (API). The Federal Energy Regulatory Commission (FERC) regulates the interstate transportation of natural gas and oil and approves LNG terminals and natural gas pipelines. Before FERC was created in 1977, Interstate Commerce Commission was responsible for regulating oil and gas transportation. There are two main categories of pipelines used to transport energy products: petroleum pipelines and natural gas pipelines. Petroleum pipelines transport crude oil or natural gas liquids, and there are three main types of petroleum pipelines involved in this process: gathering systems, crude oil pipeline systems, and refined products pipeline systems. The gathering pipeline systems gather the crude oil or natural gas liquid from the production wells. It is then transported with the crude oil pipeline system to a refinery. Once the petroleum is refined into products such as gasoline or kerosene, it is transported via the refined products pipeline systems to storage or distribution stations. Natural gas pipelines transport natural gas from stationary facilities such as gas wells or import/export facilities and deliver to a variety of locations, such as homes or directly to other export facilities. This process also involves three different types of pipelines: gathering systems, transmission systems, and distribution systems. Similar to the petroleum gathering systems, the natural gas gathering pipeline system gathers the raw material from production wells. It is then transported with large lines of transmission pipelines that move natural gas from facilities to ports, refiners, and cities across the country. Lastly, the distribution systems consist of a network that distributes the product to homes and businesses. The two types of distribution systems are the main distribution line, which are larger lines that move products close to cities, and the service distribution lines, which are smaller lines that connect main lines into homes and businesses.

5.1.1 Environmental health and safety risks Although pipeline transportation of natural gas and petroleum is considered safer and cheaper than ground transportation, pipeline failures, failing infrastructure, human error, and natural disasters can result in major pipeline disasters. As such, previous incidents have been shown to cause detrimental effects on the environment and the public’s safety.

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5.1.1.1 Land use and forest fragmentation In order to bury pipelines underground, an extensive amount of forest and land is cleared out to meet the pipe’s size capacity. States, such as Pennsylvania (PA), which consist of rich ecosystem due to their abundance of forests, are at critical risk of diminishing habitats for plant species and are at risk of the eradication of certain animal species. The United States Geological Survey (USGS) aimed to quantify the amount of land disturbance in Bradford and Washington counties in PA as a result of oil and gas activity including pipeline implementation. The USGS report concluded that pipeline construction was one of the highest sources of increasing forest patch numbers. Bradford County, PA had an increase of 306 patches, in which 235 were attributable to pipeline construction. Washington County increased by 1000 patches, in which half was attributable to pipeline construction. 5.1.1.2 Compressor stations Compressor stations play an important role in processing and transporting the materials that pass through the pipeline. However, compressor stations present significant environmental health hazards. Even when the process of drilling and fracking is completed, compressor stations remain in the area to keep the gas in pipelines continually flowing. The stationary nature of this air pollution source means that a combination of pollutants such as volatile organic compounds, nitrogen oxides (NOx), formaldehyde, and greenhouse gases is continually being released into the atmosphere. These pollutants are known to produce deleterious health impacts on the respiratory system, nervous system, or lung damage. In addition to pollutants emitted, the noise level generated by compressor stations can reach up to 100 decibels. The Center of Disease Control and Prevention reports hearing loss can occur by listening to sounds at or above 85 decibels over an extended period of time. 5.1.1.3 Erosion and sedimentation Heavy rainfall or storms can lead to excessive soil disruption, in turn increasing opportunities for erosion and sedimentation to occur. Erosion can uncover pipelines buried underground, and rainfall of more than 5 inches (13 cm) can move or erode berms and also disrupt mounds of soil used to protect against flooding. Soil erosion increases underground pipelines’ vulnerability to damage from scouring or washouts, and damage from debris, vehicles, or boats. 5.1.1.4 Eminent domain Eminent domain allows state or federal government bodies to exercise their power to take private property from residents or citizens for public use and development. In some cases, private companies have exercised the power to seize land for their own profit. Owners of the property are then given a compensation in exchange for their land. However, landowners may end upspending more than they receive. In order to receive compensation, owners must hire their own appraiser and lawyer, and they are also not usually compensated for the full value of the land. Furthermore, property values decrease once pipelines are established on their land, making it more difficult to sell their home in the future.

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5.1.1.5 Spills and leaks Poorly maintained and faulty pipelines that transport LNG or crude oil may pose high health and environmental risks such as fluids spilling or leaking into the soil. Crude oil can contain more than 1000 chemicals that are known carcinogens to humans, such as benzene. The release of the potentially toxic chemical or oil can infiltrate into the soil, exposing communities to fumes in the atmosphere as well as contaminating groundwater and surface water. Not only are the incidents costly to control and clean up, but also the chemical or oil spills can have long-lasting impacts on the environment and the public. A ruptured pipeline that leaked 33,000 gallons of crude oil in Salt Lake City, Utah in 2010 exposed residents in a nearby community to chemical fumes, causing them to experience drowsiness and lethargy. After being commissioned in 2010, the TransCanada Keystone Pipeline had reported 35 leaks and spills in its first year alone. In April 2016, the Keystone Pipeline leaked 17,000 gallons of oil in South Dakota. Older pipelines are more likely to leak than newer ones, so this issue will only increase as pipeline infrastructure ages. Natural gas pipelines have also been shown to leak methane, a major component in natural gas, at levels that far exceed what is estimated. Not only does methane contribute to climate change, but also it puts surrounding communities at risk of gas explosions and exposes them to dangerously high levels of methane in the air they breathe. 5.1.1.6 Explosions Explosions are also common with faulty pipelines that leak natural gas. Unlike oil or liquid spills, which generally spread and infiltrate into the soil, gas leaks can explode due to the hydrocarbon’s volatility. A recent pipeline explosion in Westmoreland County, PA, for example, caused a man to incur severe burns, as well as caused dozens of homes to be evacuated. Another pipeline explosion in San Bruno, California resulted in eight people dead, six missing, and 58 injured. Thirty-eight homes were also destroyed and 70 others were damaged. This explosion exposed the haphazard system of record keeping for the tens of thousands of miles of gas pipelines, shoddy construction, and inspection practices. Pipeline employees using computers remotely control the pumps and other aspects of pipeline operations. Pipeline control rooms utilize Supervisory Control And Data Acquisition (SCADA) systems that return real-time information about the rate of flow, pressure, speed, and other characteristics. Both computers and trained operators evaluate the information continuously. Most pipelines are operated and monitored 365 days a year, 24 hours per day. In addition, instruments return real-time information about certain specifications of the product being shipped—the specific gravity, the flash point, and the density, for example—information that are important to product quality maintenance. Oil moves through pipelines at speeds of 3
8 miles per hour. Pipeline transport speed is dependent upon the diameter of the pipe, the pressure under which the oil is being transported, and other factors such as the topography of the terrain and the viscosity of the oil being transported. At 3
8 mph, it takes 14
22 days to move oil from Houston, Texas to New York City (Fig. 5.4). Pipeline operators ship different petroleum products or grades of the same product in sequence through a pipeline, with each product or “batch” distinct from the preceding or following one. A pipeline operating in fungible mode also uses batch sequencing, but on

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FIGURE 5.4 Sequence of petroleum products in a pipeline.

larger size batches. One refined product or crude oil grade is injected and begins its journey, then another, and another. A batch is a quantity of one product or grade that will be transported before the injection of a second product or grade. Each pipeline publishes its batch size based on the characteristics—the logistics needs—of its shippers and on pipe size. For a pipeline operating in fungible mode, products that meet common specifications can be mixed and sent through the pipeline together as a batch. For example, a products pipeline will establish the acceptable specifications for regular grade gasoline. Shippers whose gasoline meets that pipeline’s specifications can obtain transport services for smaller volumes because their gasoline will be added to gasoline of the same quality and grade from other shippers. A shipper whose product either does not meet common specifications or for other reasons must be kept separate from other products in the line, must meet a higher minimum batch size volume before transport will be economic for the pipeline. Batching petroleum for pipeline transport has become more complex with the proliferation of product qualities (discussed more fully below). Colonial Pipeline, for instance, publishes specifications for over 100 different grades of gasoline. Crude oil pipelines, too, must meet market demands for delivering various crude types—such as high sulfur or low sulfur grades—to refineries to align with the refineries’ schedules for producing jet fuel, asphalt, diesel, and other products and to the refineries’ equipment. Lakehead Pipe Line’s 1.3 million b/d system, for instance, can contain upto 50 batches of crude oil of distinct qualities. There is always a certain amount of intermixing between the first product and the second at the “interface,” the point where they meet. If the products are similar, such as two grades of gasoline, the resulting mixture is added to the lower-value product. If the products are dissimilar, such as diesel and gasoline, the “transmix,” the hybrid product created by intermixing at the interface, must be channeled to separate storage and reprocessed.

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Pipeline operators establish the batch schedules well in advance. A shipper desiring to move product from the Gulf Coast to New York Harbor knows months ahead the dates on which Colonial will be injecting heating oil, for instance, into the line from a given location. On a trunk line, a shipper must normally “nominate” volumes—ask for space on the line—on a monthly schedule. Delivering lines, by their nature, have more changeable schedules; shippers can secure space on them with a shorter lead time, possibly even the same day. It is not uncommon for tendered volumes to differ from nominated volumes, especially on delivering lines. These lines, by their nature, are closer to the end user and must be responsive to the changing needs of shippers and their customers. Hence, the last-minute changes that are essential to the oil market balance are a routine part of pipeline operations. As common carriers, oil pipelines cannot refuse space to any shipper that meets their published conditions of service. If shippers nominate more volumes than the line can carry, the pipeline operator allocates space in a nondiscriminatory manner, usually on a prorata basis. This is often referred to in the industry as “apportionment” (space cannot be allocated to the highest bidder, nor on a first come, first serve basis. Pipeline rate structures are discussed in more detail below). During the peak seasons, it is common for some pipelines to be using apportionment. Such bottlenecks invite competition, of course, either from other modes of transportation or from pipeline alternatives. The need to allocate space also encourages capacity expansion. The supply of gasoline to the Midwest from the Gulf Coast provides an example. Explorer Pipeline recently announced a capacity expansion, and Centennial Pipeline, a line newly converted from natural gas to refined products transport, will offer a competing service beginning in 2002. This Gulf Coast-to-Midwest refined products capacity expansion is just one example of how the pipeline industry responds to structural shifts taking place in oil markets. There are many others: the conversion to product service (or in a few cases to natural gas service) of a number of crude oil lines idled or underutilized by declining crude oil production; new pipeline initiatives to supply refined products to the Salt Lake City area from PADD 3; also in the Salt Lake City area, newly increased pipeline utilization from using Canadian crude oil to meet newly developed local market needs rather than shipping the crude through PADD 4 into PADD 2, as a recent pipeline expansion had anticipated. There are also the changes brought about by refinery closures. These plants have become uneconomic for a variety of reasons, including the imposition of a new set of emissions standards as the plants install new equipment to meet new product mandates. The supporting infrastructure—crude oil lines into, and refined product pipelines out of the facility—cannot necessarily be adapted to the new supply pattern that develops to substitute for the refinery’s supply, so many of these lines are being idled. The mandate for different products regionally and seasonally has led to the infrastructure being more tautly stretched. This makes it more difficult to accommodate the routine and frequent changes described above, which are at the core of the oil market’s reality and its efficiency. A major product pipeline like the Colonial Pipeline, which carries refined products from Texas to the New York City area, must carry many different grades of gasoline in order to accommodate product quality mandates that vary both seasonally and regionally; Colonial Pipeline, as noted, publishes specifications for 100 distinct grades of gasoline on an annual basis.

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The new products require more batching and allow less scheduling flexibility. They also increase the number of interfaces, thus requiring more product to be downgraded from one grade to the next lower grade. The most stringent regulations have increased the volume of transmix, the amount of product that must be reprocessed to meet specifications. The proliferation of distinct grades has effectively reduced the capacity of both the refinery and the distribution system. Terminals are a critical part of the delivery infrastructure and impact pipeline operations. In some instances, shippers on the pipeline or independent operators own the terminals. In other instances, the pipeline transporter provides storage (terminal) services. The proliferation of mandated product grades leads to underutilization of tankage and other assets, creating challenges for any terminal operator and all pipelines alike. A good example comes from the change over to a new mandated product such as the special “reformulated gasolines” required in some areas (a one-time event for each phase of the program over a matter of years), or the seasonal changeover to the gasoline meeting more restrictive summer volatility requirements (an annual occurrence). Tanks must be almost completely drained of the old product that meets the less stringent requirements before being filled with the new product that meets the more stringent requirements. This forced underutilization reduces system flexibility and complicates product flow. This changeover generally occurs with enough lead time before the regulatory deadline to allow several shipments of the more stringent (new) product to flush out the less stringent (old) product. Many tank farms operate at capacity and do not have the space or permitting flexibility to add new tankage. As a result, tank farms must anticipate product usage during the seasonal cusp period—the shoulder season—in order to accomplish this turnover without encountering product shortages. Any disruption in the supply of product to the terminal during this shoulder season or any unexpected surge in demand can lead to localized product shortages. For delivering lines, a seasonal or other upheavals in terminal logistics can be particularly disruptive. These lines depend on delivering each product to each terminal in sequence. If the tank at a near terminal cannot accept the shipment, and if the pipeline does not have a more distant substitute customer for the product, pumping may need to stop. In addition to the inefficiency and loss of capacity, stopping a pipeline’s flow, even in a planned manner, presents a number of operational challenges, including maintaining the interface. Further, many of the terminals along a delivery line cannot accept shipments at the full rate of flow. Pipelines routinely “strip” deliveries into these facilities, diverting a portion of the flow to the terminal, with the remainder of the flow continuing to more distant points. If there is no customer for a particular special product further down the line, the entire pipeline must slow to the rate of flow that the near terminal can accept. This enforced slowing, too, creates inefficiency and loss of capacity (Fig. 5.5). FIGURE 5.5 Distribution of pipeline products.

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These operational challenges will be magnified in transporting the newly mandated ultra-low sulfur diesel. The Environmental Protection Agency’s (EPA’s) comprehensive rule on heavy truck engines and diesel fuel quality requires that beginning with the 2007 model year, heavy trucks meet new emissions standards. The new sulfur content regulations for diesel fuel are a corollary, requiring that on-highway diesel fuel contains no more than 15 ppm sulfur beginning in mid-2006. During the phase-in period, to 2010, a refiner may continue to produce some 500-ppm diesel fuel such as that now required for onhighway use—up to 20% of its on-highway diesel fuel output, or more if it purchases trading rights to do so. Pipelines will be carrying both the 500-ppm product and the new 15ppm product and must maintain product integrity of the separate specifications. For the limited time of the phase-in period, then, pipelines will be meeting the demands for tankage and other logistical difficulties presented by the introduction of an additional (not a substitute) product.

5.1.2 Large pipeline projects 5.1.2.1 West-East pipeline project West-East Gas Pipeline Project (WEPP) is one of the major natural gas transmission projects intended to connect the eastern markets of China, with western resources to allow mutual and sustainable development. The project involves the construction of four pipelines that will travel along varied terrains to link the 560,000 square kilometer Tarim Basin in Xinjiang Autonomous Region and Turkmenistan with the Yangtze Delta and Pearl Delta regions. The first West-East gas pipeline, measuring 4000 km, opened in December 2004 and a section of the second WEPP was commissioned in June 2011. WEPP II will measure 8704 km once complete and travel through 15 provinces. A feasibility study for the third pipeline (WEPP III) has been initiated and the project is expected to be completed by 2014. WEPP IV is still in the planning stage. 5.1.2.2 Wloclawek gas compressor station The Yamal
Europe pipeline is a natural gas distribution system running across Russia, Belarus, Poland, and Germany. The 4107-km-long pipeline has a diameter of 1420 mm and can carry 33 billion cubic meters a year. Construction was carried out by dividing the length of the pipeline into different sections. The 402 km Russian segment starts from the Torzhok gas transmission hub and receives gas from the Northern Tyumen Regions
Torzhok gas pipeline. The 575 km Belarusian section runs across Belarus and includes five compression stations at Nesvizhskaya, Krupskaya, Slonimskaya, Minskaya, and Orshanskaya. The Polish pipeline measures 683 km long and passes through 32 railway lines, 246 roads, 108 surface water streams, and 7 large rivers. The German section is connected to the YAGAL
Nord gas transmission system, which is in turn connected to the STEGAL
MIDAL
Rehden UGS gas transmission system.

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5.1.2.3 Eastern Siberia
Pacific Ocean pipeline Once constructed, the Eastern Siberia
Pacific Ocean (ESPO) oil pipeline will export crude oil from Russia to the Asian Pacific markets of Japan, China, and Korea over a length of 4700 km. The original project proposed to build a pipeline from Angarsk, Russia to Daqing in northern China. This was then combined with a pipeline project from Taishet in Irkutsk Oblast to the Far East port of Kozmino near Nakhodka in May 2003. In October 2008, the section between Taishet and Talakan was launched in a reverse to pump oil from Surgutneftegas-owned Alinsky deposit. This pipeline was completely laid in May 2009. The 1963 km section from Taishet to Kozmino will run 882 km through the Amur region, 324 km through the Jewish autonomous region, 247 km through Khabarovsk territory, and 570 km through Primorye. Feasibility studies for this section have been completed and the pipeline is expected to be fully laid by 2014. 5.1.2.4 Keystone XL Keystone XL Pipeline is a new 1897 km-long crude oil pipeline planned by TransCanada. The cross-border pipeline will run from Hardisty in Canada to Steele City in the US state of Nebraska and cost around $7 billion to construct. The pipeline, expected to help the US reduce its natural gas imports from the Middle East and Venezuela, will transport crude oil from the Western Canadian Sedimentary Basin and Bakken supply basin to the existing Keystone Pipeline at Steele City for further delivery to US refineries on the Gulf Coast. The project received approval from the National Energy Board of Canada in March 2010. At the same time, the US Department of State extended the deadline for federal agencies to decide if the pipeline is in the national interest, and in November, 2011, President Obama postponed the final decision on the proposed project until 2013. 5.1.2.5 Kazakhstan
China pipeline The 2798-km-long Kazakhstan
China pipeline transports crude oil from oil fields located in western Kazakhstan to the Dushanzi refinery in Xinjiang province of China. Construction of the pipeline was divided into three segments and carried out in two phases. The first phase included a 448 km-long first section which starts at Atyrau near the Caspian Sea and ends at Kenkiyak, Kazakhstan. This section became operational toward the end of 2003. The second phase included the construction of a 962 km pipeline, which runs from Atasu in Kazakhstan to Alashankou in China, and a 761 km section which runs from Kenkiyak to Kumkol in central Kazakhstan. In January 2011, the pipeline met its design capacity for the first time. It had transported more than 30 mt of crude oil since the commissioning of the first section in 2006. The second phase was completed in July 2009. 5.1.2.6 Rockies express pipeline The Rockies Express cost $5.6 billion to complete and has the capacity to supply about 16.5 billion cubic meters of natural gas a year.

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The Rockies Express cost $5.6 billion to complete and has the capacity to supply about 16.5 billion cubic meters of natural gas a year. The Rockies Express is a 1679-km-long pipeline, which runs between the Rocky Mountains in Colorado and Eastern Ohio. One of the largest pipelines ever constructed in the United States, the Rockies Express cost $5.6 billion to complete and has the capacity to supply about 16.5 billion cubic meters of natural gas a year. The project was completed in three sections. The 528 km REX Entrega section runs between the Meeker Hub in Rio Blanco County in Colorado and the Cheyenne Hub in Weld Country, Colorado. The REX West section, which is divided into seven spreads, runs 1147 km in a 1070 mm pipe from Weld County to Audrain County in Missouri, near St Louis. There is also an 8 km, 610 mm branch connecting to the Williams Energy-owned Echo Springs Processing Plant in Wyoming. The final section of the pipeline, REX East, is a 1027 km, 1070 mm pipeline running from Audrain County, Missouri, to Clarington in Monroe County, Ohio. This section was completed in November 2009. 5.1.2.7 Trans-mediterranean natural gas pipeline The Trans-Mediterranean (Transmed) is a 2475 km-long natural gas pipeline built to transport natural gas from Algeria to Italy via Tunisia and Sicily. Built in 1983, it is one of the longest international gas pipeline systems and has the capacity to deliver 30.2 bcm/y (billion cubic meters per annum) of natural gas. The Transmed pipeline begins in Algeria and runs 550 km to Tunisian border. From Tunisia, the line passes 370 km to El Haouaria in the Cap Bon province and then crosses the 155 km-wide Sicilian section. Passing through Mazara del Vallo in Sicily, the pipeline moves a further 155 km from Sicily to the Strait of Messina and 1055 km in the Italian mainland to northern Italy with a branch to Slovenia. The pipeline consists of nine compressor stations, including one in the Algerian section, three in the Tunisian section, one in Sicily, and four in the Italian section.

5.2 Gas pipeline systems Recently, natural gas consumption increased significantly, reaching 3,822.8 billion cubic meters (bcm) in 2020, owing to the increasing demand for natural gas in multiple industries, including power generation and transportation (Fig. 5.6). This trend is expected to continue in the coming years and is likely to drive the gas pipeline infrastructure significantly. By 2030, due to environmental benefits and the quest for energy security in regions such as the Middle East, Africa, and Asia-Pacific, the demand for natural gas is expected to witness significant growth among all fuel types. With the exports of 197.2 bcm of gas per year in 2020, Russia continued to be the largest LNG exporter globally. The LNG trade is expected to witness a significant increase globally, resulting in increased demand for the natural gas pipeline network. Moreover, in January 2020, the Indian government approved USD 774 million for a natural gas pipeline network in the northeast region as part of a national gas grid being built to span

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FIGURE 5.6 Natural gas consumption in recent years.

remote locations in the country. The 1656 km pipeline is expected to cost upto INR 92.65 billion and is expected to be completed by 2023. The development of new sources of natural gas, such as shale gas deposits, and the resulting price pressure are increasing the international trade of natural gas. Hence, these developments are expected to consequently result in increasing the demand for pipeline network expansion during the forecast period. It is expected that Asia-Pacific will dominate the pipeline market. The energy consumption in Asia-Pacific is expected to increase by upto 48% by 2050. According to the International Energy Agency (IEA), China is expected to contribute 30% of the world’s energy increase until 2025. Moreover, natural gas imports have continuously increased in China and reached 138.371 bcm in 2020, thus meeting the increasing demand. China’s state-owned firms, including CNPC and China National Offshore Oil Corporation, have plans to maximize production at local gas fields, further driving the pipeline demand in the region. India is also modifying its gas pipeline infrastructure to meet the growing demand. In the annual budget of 2021, the Indian government announced a pipeline project for the union territory of Jammu and Kashmir. Apart from this, the nation aims to increase the natural gas share to 15% in the energy basket and expect USD 66 billion investment in building the gas infrastructure, including gas pipeline, City Gas Distribution (CGD), and LNG regasification terminals. Moreover, in December 2020, the Indian government announced a USD 60 billion investment for creating gas pipeline infrastructure, which covers the expansion of Compressed Natural Gas pipeline networks in 232 geographical areas across the country by 2024. Therefore, the increasing demand and new pipeline infrastructure in Asia-Pacific are significant factors driving the market growth of oil and gas. The oil and gas pipeline market is moderately fragmented (Figs. 5.7 and 5.8). Some major players operating in this market include Nippon Steel Corporation, Tenaris Inc., TMK Group, ChelPipe Group, and Mott Macdonald Group Ltd. Most recently, the following events are occurred: (Fig. 5.9) 1. In February 2021, Virginia natural gas company RGC Resources Inc. announced that the joint venture is building the Mountain Valley gas pipeline worth USD 5.8 billion
USD 6.0 billion from West Virginia to Virginia. The pipeline is expected to be completed by mid-2022.

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FIGURE 5.7 Oil and gas pipeline market.

FIGURE 5.8 Market concentration.

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5.3 Historical perspective

Large-diameter U.S. pipeline ownership thousand miles of pipeline

Kinder Morgan TransCanada Energy Transfer Spectra Energy Williams

Top 10 pipeline owners

Boardwalk Berkshire Hathaway

Williams/Energy Transfer merger (canceled)

Enable

Enbridge/Spectra merger (proposed)

PG&E Dominion 0

eia

5

10

15

20

25

30

35

40

Source: Pipeline and Hazardous Materials Safety Administration Form F7100.2-1 Part H for Transmission Pipeline Miles by Diameter for 2015. Notes: Includes both interstate, intrastate, and offshore natural gas transmission (excludes gathering pipe). Also includes pipe with shared or partial ownership.

FIGURE 5.9

Recent mergers of pipeline companies. Source: Graphic courtesy of the US Energy Information

Administration.

2. In August 2021, the Dakota Access Pipeline (DAPL) Expansion project increased its capacity by 180,000 BPD along with the DAPL system by adding horsepower and upgrades at pump stations. The DAPL system runs from North Dakota through South Dakota and Iowa and ends near Patoka, Illinois, in the United States. EIA: Recent mergers change the landscape of natural gas pipeline ownership

5.3 Historical perspective The developments in the pipeline industry can be divided into the following temporal phases: 1. 2. 3. 4. 5. 6.

1851
75: combustion and kerosene 1875
1900: short lines and leaky joints 1900
25: longer pipes, higher pressures 1925
50: depression, competition, war, and peace 1950
75: pipelining comes of age 1975
2000: the regulatory era

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5.3.1 1850
75—pipelines During this era, the following companies contributed: 1. 1962: Barrows and Company constructed a pipeline of about 800 feet from one of their wells to their refinery near Tarr Farm, PA. 2. 1863: Hutchins and Company built a 2-mile long 2-inch diameter pipeline from Tarr Farm to the Humbolt Refinery at Plummer. It rose 400 feet in elevation and used 3 pumps. 3. 1865: Samuel Van Syckel from Pit Hole, PA to Miller’s Farm, on the Oil Creek Railroad, about 5 miles away. The 81 barrels per hour it moved did the work of 300 teams working 10 hours. 4. 1872: Bloomfield and Rochester Natural Gas Light Company built a 25-mile pipeline from Bloomfield to Rochester from hollowed out Canadian white pine logs. In terms of landmark engineering events, the following events took place during this era: 1855: Darcy’s law was published. 1856: Bessemer steel is developed. 1863: pipelines joined by screwed couplings. 1863: standardized metering for gas started with the formation of the American Metering Company. 5. 1869: hydraulic testing of pipe begins as a quality assurance test. 6. 1871: Bessemer steel begins to displace wrought iron. 1. 2. 3. 4.

The earliest oil pipelines in the United States, laid in the 1860s, started soon after the drilling of first series of oil wells. At that time, pipelines were typically constructed of 2-in cast-iron pipe threaded and screwed together in short segments. The driving force for displacing oil through the pipeline was provided through steam-driven, single-cylinder pumps, or by gravity feed. These were relatively short-length pipeline systems, rarely exceeding 15 miles in length (Gravel et al., 2018). The most important shortcomings of this system are as follows: 1. prone to bursting; 2. thread stripping at the pipe joints; 3. frequent pump breakdowns mainly due to the percussive strain on the lines caused by each stroke of the pump, which “resembled the report of a rifled gun.” Bursting of a pipeline is caused by one or more of the following reasons: 1. Excessive fluid pressure It is a common cause of pipes bursting and results from build-up of pressure to a point the pipe cannot handle. The excess pressure is often caused by pipes clogging thus narrowing the cross-section. A warning sign for this kind of danger would be the fluctuation of the fluid flow or dramatic reduction. If this happens, there is a high chance that there is a blockage somewhere and very soon a pipe burst will occur somewhere, usually at a point where the pipeline is weak. 2. Freezing weather Cold winters usually cause pipes to burst. Water in the pipes starts to freeze. Freezing causes the water to expand, and when the pipe cannot take in the expansion, it bursts. A similar problem occurs in the presence of gas, for which gas hydrates can plug the flow line.

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333

3. Exposure to weather and other activities Pipes that are not laid underground are prone to damage both from natural factors and human activities. They are exposed to the sun and other weather elements, which cause them to deteriorate over time and in the long run cause them to corrode and crack. Activities such as construction can also lead to accidental bursting of pipes. 4. Poor quality pipes Pipes that are manufactured out of poor quality materials or which were faulty at the time of manufacturing are susceptible to bursting. Before laying them in the pipeline, they should be adequately inspected for quality and faults. This used to be a real issue during the early days of petroleum production. 5. Tiny cracks in the pipes Cracks that are tiny and almost invisible are a cause of future pipe burst. They enlarge over time and when they start to let fluid through, the pipe bursts. This is why pipes should be inspected for cracks, right from the initial installation to during routine maintenance inspections. Pipe joints are considered to be the weak links in a pipeline system. These points often are known to have a higher failure potential than the pipe itself. This is reasonable since joining normally occurs under uncontrolled field conditions. Highest points are awarded when high quality of workmanship is seen and all were brought into compliance with governing specifications. Point values should be decreased for less than 100% weld inspection, questionable practices, or other uncertainties. Other joining methods (flanges, screwed connections, polyethylene fusion welds, etc.) are similarly scored based on the quality of the workmanship and the inspection technique. This process has improved greatly over the last 100 years (Muhlbauer, 2004). However, stripping at pipe joints remains a cause of concern. Pipe strain is the primary cause of pump breakdowns. It is caused by a misalignment between the pump suction and discharge flanges and the corresponding pipe flange connections (Fig. 5.10). Unacceptable pipe strain can be defined as any force (from unanchored piping) that will cause equipment deformation of more than .002.

FIGURE 5.10 Sources of pipe strain.

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5. Transportation of oil and gas

Free bolting is one method that can be used to ensure that no bending moments will be transmitted to the pump. This practice involves confirming that all bolts will slide freely through the holes in both the pump flanges and the pipe flanges without exerting force. A common engineering practice is to specify the bolt holes in flanges to be drilled 1/8-in larger than the diameter of the connecting bolts. This practice is consistent with the alignment specification in ANSI/ASME B31.3, which states “Flanged joints shall be aligned to the design plane within 1/16-in/ft measured across any diameter. Flange bolt holes shall be aligned within 1/8-in maximum offset.” Parallel and angular misalignment of piping flanges at the pump nozzle results in excessive nozzle loads. Excessive nozzle loads create stresses in pump hold-down bolts as well as distortion in pump supports and baseplates. Other than the serious imbalance of pump components, there is no single detractor of equipment reliability more significant than poor alignment. Incorrect alignment between pump and driver couplings can cause extreme heat in couplings, which leads to hub, keyway, and grid failure. Reverse bending fatigue creates excessive loads that can bend, crack, or break a pump shaft and excessive radial and thrust loads, leading to premature radial and thrust bearing failure. Forcing piping in place for attachment to the pump suction and discharge flanges can easily create excessive loads in pump nozzles that stress materials and produce bending moments. These distort internal moving parts and affect critical radial clearances. Rubbing caused by radial clearance losses between rotating and stationary elements rapidly damages component parts and requires more power to rotate the pump shaft. In the next phase of pipeline development, the focus was on increasing the pipeline length. By the 1870s, a 2000-mile network of small-diameter gathering lines connected the oilproducing areas with regional refineries and storage points on the railroads and rivers where the oil could be shipped to refineries via railcars or ships and barges. Typical crude oil trunk lines were constructed of 18-ft sections of lap-welded wrought iron pipe 5” or 6” in diameter joined with tapered, threaded joints manufactured specifically for pipeline service. The lapwelded technology was introduced in the mid-19th century (Scientific American, 1858). The advent of railroads called into existence extensive manufactures of copper and brass tubing for the flues of locomotive boilers. Previous to that era, gun barrels and gas pipes of small companies had been manufactured of wrought iron, but lap-welded iron tubes were new. Owing to the high, price of copper and brass in comparison with iron, many persons in England especially were incited to invent machinery to manufacture unriveted wrought iron tubes of various sizes, to supersede those of the more expensive metals. Their efforts were at last successful as the lap-welded iron tubes were then extensively used for all kinds of multitubular boilers and various other purposes. Lap-welded iron tubes were first introduced into the United States about the year 1845 by Thomas Prosser & Son and were manufactured under an European patent previously secured. Soon after this, various attempts were made to make this a branch of local manufactures, and for this purpose, one firm in Philadelphia employed several mechanics who had been engaged in the business in England; but after a considerable expenditure of money, their efforts failed of success, and it was not until 1852 that American lap-welded iron tubes became a “fixed fact.” This was accomplished by machinery designed, constructed, and operated by Joseph McCully, or the well-known firm of Morris, Tasker & Morris, of Philadelphia. The sheet of metal or a tube is first drawn through a scarfing machine, which has two cutter heads for matching the edges of the sheet

Pipelines

5.3 Historical perspective

335

to form the lap, much in the same manner as the stationery cutters for matching boards, only the form of the chisels are different. After the scarfing operation is performed, the sheet or skelp is heated in a reverberatory furnace to prepare it for the bending operation. This is executed by a machine, through which the heated skelp is drawn, and it is upset or bent by dies, and the lap is laid ready for welding. It is now heated a second time, in a similar furnace, to the welding heat, after which it is passed over a bill-pointed ball placed between rolls fluted in such a manner that, as they roll and press upon the formed tube, they weld the lap without leaving any fin upon it, and at the same time they feed the tube back as fast as it is welded, over a long movable rod or bar attached to the ball on which the tube is squeezed. After the lap-welding is completed from end to end of the tube, the iron rod is withdrawn and the tube—still hot—is taken out and passed between friction rollers which straighten, smooth, and finish it ready for market. In this manner, by four operations and two heats, American lap-welded iron tubes, are manufactured from sheets or skelps of wrought iron. The machinery employed is simple and well arranged for performing the successive operations, and it is, in many respects different from the machinery and processes employed and practiced in England in the same business. Hitherto, tubes of this character have only been made from one to eight inches in diameter, but the machinery of Mr. McCully was capable of making 12-inch pipes, which, when manufactured, will undoubtedly take the place of riveted flues in long cylindrical boilers, also the riveted pipes employed for the chimneys of some steamers and locomotives. The use of lap welding to manufacture pipe was introduced in the early 1920s. Although the method is no longer employed, some pipe that was manufactured using the lap-welding process is still in use today. In the lap-welding process, steel was heated in a furnace and then rolled into the shape of a cylinder. The edges of the steel plate were then “scarfed.” Scarfing involves overlaying the inner edge of the steel plate, and the tapered edge of the opposite side of the plate. The seam was then welded using a welding ball, and the heated pipe was passed between rollers which forced the seam together to create a bond. The welds produced by lap welding are not as reliable as those created using more modern methods. The American Society of Mechanical Engineers (ASME) has developed an equation for calculating the allowable operating pressure of pipe, based on the type of manufacturing process. This equation includes a variable known as a “joint factor,” which is based on the type of weld used to create the seam of the pipe. Seamless pipes have a joint factor , E (Seamless pipe/tube) 5 1.0 (Fig. 5.11). Sarbanes et al. (2020) used finite element models for elucidating some interesting features of lap-welded joint behavior under severe bending deformation, toward determining the joint strength, its deformation capacity, x.@m56, and the evolution of strain at different deformation stages. The experimental and numerical results indicate that lap-welded joints, can sustain a significant level of bending deformation and strain, without loss of pressure containment, and can be used in geohazard areas, where severe permanent ground-induced strains on the pipeline wall are expected to develop. They compared a 3.429 mm (0.135 in), referred to as “thin-walled pipe,” with ASTM A1011 SS GR36 steel, with wall thickness equal to 6.35 mm (0.25 in), referred to as “thick-walled pipe” with ASTM A1018 SS GR40 steel. The stress
strain curves obtained experimentally by coupon tests, for the two pipes are shown in Fig. 5.12. For the thin-walled pipe, the yield stress is equal to 303 MPa, the ultimate tensile stress is equal to 438 MPa and the

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FIGURE 5.11 Lap-welded steel pipeline joints. (A) Schematic configuration of a lap-welded pipe joint; (B) detail at the weld region. Source: From Sarbanes, G.C. et al., 2020, Bending response of lap welded steel pipeline joints. Thin-Walled Struct. 157. 107065, ISSN 0263-8231. Available from: https://doi.org/10.1016/j.tws.2020.107065.

FIGURE 5.12 Axial stress versus strain material curves for the two pipes under consideration (Sarvanis et al., 2020).

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5.3 Historical perspective

337

total elongation is equal to 46.5%. For the thick-walled pipe, the stress is equal to 362 MPa, the ultimate tensile stress is equal to 505 MPa and the total elongation is equal to 43.2%. In the beginning, the practice was to bury the pipe and the pipe was generally buried 2 or 3 ft below the ground surface. Worthington-type pumps were used as the motive power for the lines, and the pumps were powered by steam generated by coal-fired boilers. Pump stations were spaced as needed to maintain the flow of oil over the terrain crossed by the lines. At the pump stations, oil was withdrawn from the lines and passed through riveted steel receiving tanks some of which were 90 ft in diameter and 30 ft high holding about 35,000 barrels (Scientific American, 1892). Diesel-powered pumps began to replace steam power around 1913
14 ( Crafts, 2004). This was a meaningful transition. Steam power evolved over a period of several 100 years—this is possibly explained because its power source (water and heat) has been readily available throughout history, unlike other fuels requiring more involved processes to be created (i.e., diesel or electricity). As such, steam engine also represents greater sustainability than diesel engines. Outwardly, steam engines are considered to be only around 10% efficient, whereas efficiency of diesel engines hovers at around 45%. However, if global efficiency is considered, steam their efficiencies are comparable. It is also true that the original intent of Mr. Diesel, inventor of diesel engine, was to use vegetable oil. Apparently, Diesel’s inability to successfully market his invention led him to get a nervous breakdown. Further complexity arose after his disappearance and presumed suicide in 1913 on a sea voyage from France to England. After his patents expired several other companies snapped up his invention and developed it into the modern diesel invention. This diesel is entirely based on petroleum resources, although the recent push to develop “green energy” led to the development of biodiesel (Chhetri and Islam, 2008). Why did Diesel power replace steam power? The replacement of steam locomotives with their diesel counterparts took place between the 1930s and 60s and is often referred to as “Dieselisation.” At the outset, diesel locomotives were less powerful than steam engines, which meant smaller train sizes (i.e., the amount of carriages they could tow), which we would have thought made them a less preferable option—so why make the switch? The following reasons are cited: 1. The diesel engine has an impressively high thermal efficiency—with modern diesel engines achieving 45% efficiency compared to steam engine achieving 10% efficiency, giving them to achieve greater distances between refueling stops. 2. The absence of water stops and reduced inspection and repair costs resulted in greatly reduced overall running costs. 3. Outward cleanliness of diesel engines as compared to steam engines.

5.3.2 1876
1900 Following important events took place during this era: 1. 1878: First Russian crude oil pipeline, 3-inch diameter, 6 miles long from Baku to Balakhany. 2. 1879: Tidewater Pipeline, a 6-inch diameter 110-mile wrought-iron pipeline built. 3. 1881: Jacob Vandergrift’s United Pipe Lines controlled 12,000 miles of 2 in. and 4 in. gas gathering lines and 600 miles of larger diameter interstate trunk lines. 4. 1900: about 6800 miles of crude oil lines in the United States, nearly 90% owned by Standard Oil.

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Meanwhile, the following technological events took place: 1. 2. 3. 4. 5. 6.

In 1883, Reynolds number was introduced. In 1891, Dresser coupling was developed to join pieces of pipe end to end mechanically. In 1897, the first 30” diameter lap-welded pipe was made. In 1899, the first large diameter (20”) seamless pipe was made, 5/8” wall thickness. In 1899, internal combustion was used to power natural gas compressors. In 1900, the most lap-welded pipe was made from steel; open hearth steel making was the predominant process.

The next big milestone was hit when in May 1879 the Tidewater Pipe Company, Ltd. began operation of the first long-distance crude oil pipeline covering the 100 miles between Coryville and Williamsport, PA, to connect with the Reading Railroad. The line was constructed of 6” wrought-iron pipe laid on the surface of the ground (except when crossing cultivated land) and relied on only two pumping stations, one at Coryville and the other near Coudersport. Wrought iron is composed primarily of elemental iron with small amounts (1%
2%) of added slag (the by-product of iron ore smelting, generally consisting of a mixture of silicon, sulfur, phosphorous, and aluminum oxides). Wrought iron is made by repeatedly heating the material and working it with tools to deform it. Wrought iron is highly malleable, allowing it to be heated and reheated, and worked into various shapes—wrought iron grows stronger the more it is worked and is characterized by its fibrous appearance. Wrought iron contains less carbon than cast iron, making it softer and more ductile. It is also highly resistant to fatigue; if large amounts of pressure are applied, it will undergo a large amount of deformation before failing. Understandably, the expansion of the oil under the hot summer sun caused the line to shift as much as 15
20 ft from its intended position, knocking over telegraph poles and small trees, but no serious breaks occurred. In the spring of 1880, Tidewater buried the entire line (Williamson and Daum, 1959). Table 5.1 compares the composition of various types of iron and steel. Table 5.2 lists the properties of wrought iron. Among its other properties, wrought iron becomes soft at red heat and can be easily forged and forge welded. It can be used to form temporary magnets, but cannot be magnetized permanently, and is ductile, malleable, and tough. The success of the Tidewater pipeline set the pattern for the construction of other longdistance crude oil “trunk” lines, which sprang up in the early 1880s connecting the oil regions of PA with refining centers in Cleveland, Pittsburg, Buffalo, Philadelphia, Bayonne, and New York City (Williamson and Daum, 1959). Trunk and flow lines are pipes connecting the wells with the treatment plants. Flow lines are the connection from the well itself, to either a treatment plant or a gathering station. The trunk lines are usually the bigger lines. They carry often a lot of oil to the final treatment. The same name is used for gas pipelines. TABLE 5.1 Chemical composition comparison of pig iron, plain carbon steel, and wrought iron. Material

Iron

Carbon

Manganese

Sulfur

Phosphorus

Silicon

Pig iron

91
94

3.5
4.5

0.5
2.5

0.018
0.1

0.03
0.1

0.25
3.5

Carbon steel

98.1
99.5

0.07
1.3

0.3
1.0

0.02
0.06

0.002
0.1

0.005
0.5

Wrought iron

99
99.8

0.05
0.25

0.01
0.1

0.02
0.1

0.05
0.2

0.02
0.2

All units are in percent weight.

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TABLE 5.2 Properties of wrought iron (Oberg et al., 2000). Property

Value

Ultimate tensile strength [psi (MPa)]

34,000
54,000 (234
372)

Ultimate compression strength [psi (MPa)]

34,000
54,000 (234
372)

Ultimate shear strength [psi (MPa)]

28,000
45,000 (193
310)

Yield point [psi (MPa)]

23,000
32,000 (159
221)

Modulus of elasticity (in tension) [psi (MPa)]

28,000,000 (193,100)





Melting point [ F ( C)]

2800 (1,540)

Specific gravity

7.6
7.9 7.5
7.8

From Oberg, E., Jones, F.D., Ryffel, H.H., 2000. Machinery’s Handbook, twentysixth ed. Industrial Press, Inc., New York, p. 476. ISBN 08311-2666-3.

5.3.3 1901
25 The following iconic petroleum events took place during this era. 1. 2. 3. 4.

1. 2. 3. 4. 5. 6.

Gas was well established as a lighting, cooking, and heating source. Locally manufactured gas or locally produced natural gas was used. Gasoline was beginning to rival kerosene as the liquid fuel in the highest demand. Experimentation with long-distance pipelining was in full swing a. Pipe manufacturing methods. b. Steel properties. c. Joining techniques. d. Compressor and pump technologies. In 1900, most lap-welded pipe is made from steel. In 1911, one-mile pipeline is constructed with oxy-acetylene girth welds. In 1915, depleted reservoirs are used to store gas. In 1917, 11-mile pipeline is welded with electric metal arc welding. In 1924, a process for making line pipe by electric resistance welding with direct or low-frequency current is invented. In 1925, large-diameter seamless pipe (made by the plug mill process) becomes available (24” diameter). This is the period both federal and state governments weighed in designing regulations:

1. 2. 3. 4. 5. 6.

1903: Elkins Act passed by Congress. 1903: Bureau of Commerce established by Congress. 1905: The Garfield Investigation looks into pipeline practices in Kansas. 1906: Hepburn Act passed by Congress. 1906: ten states required oil pipelines to be common carrier. 1921: Iroquois Natural Gas ordered by the NY Public Service Commission to augment its supply of natural gas with manufactured gas.

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The following technological/business events took place during this era: 1901: Forchheimer equation for describing gas flow through porous media introduced. 1901: Spindle Top drilled near Beaumont. 1908: British Thermal Unit (BTU) used for the first time in Wisconsin 1911: standard divests of Buckeye Pipeline 1914: gasoline displaces kerosene in the United States in terms of value produced. 1916: US National Academy of Science establishes the Baume scale for measuring specific gravity of liquids. 7. 1921: API establishes API Gravity as the petroleum measure for hydrocarbon liquids. 1. 2. 3. 4. 5. 6.

During this era, the following pipeline events took place: 1904: Pure Oil built a 300-mile 5-inch kerosene line from Western PA to Marcus Hook. 1904: first major gas transmission pipeline, 16” diameter. 1904: the state of Texas had 513.5 miles of crude pipelines. 1907: Transcaucasus Railroad put into operation a 550 mile long kerosene pipeline between Baku and Batum. 5. 1907: Gulf Pipeline built a 6-inch 480-mile line from Glennpool, OK to Port Arthur, TX. 6. 1925: the first long distance all welded pipeline is laid by Magnolia Gas from North LA to Beaumont, Texas. It is 217 miles long and consisted of 14, 16, and 18-inch diameter pipe. 1. 2. 3. 4.

By 1905, the oil fields in the Oil Regions of Appalachia stretching from Wellsville, New York, through western PA, West Virginia, eastern Ohio, Kentucky, and Tennessee were becoming depleted. The new oil fields discovered during the early 1900s in Ohio, Indiana, Illinois, southeastern Kansas, northeastern Oklahoma, and eastern Texas were quickly connected by trunk lines to the eastern refining centers as well as the new western refineries in Lima, Ohio; Whiting, Indiana; Sugar Creek, Missouri; and Neodesha, Kansas (Johnson, 1967). The proximity of the prolific Spindle Top Field to the Gulf coast made the area around Houston, Port Arthur and Beaumont, Texas, and Baton Rouge, Louisiana into a petroleum refining center. Regional pipelines were built to carry crude oil the relatively short distances to the Gulf coast refineries (Johnson, 1967). The oil tanker ships operating from the Gulf coast ports competed for and obtained control of most of the long-distance oil transport to the refineries and markets along the eastern seaboard by the mid-1920s (Williamson et al., 1963; Johnson, 1967). Until the 1930s, when large-diameter steel pipe was in widespread use, the carrying capacity of oil pipelines was increased by laying an additional line or lines alongside the original pipe within the same right-of-way. This practice was known as “looping.” The carrying capacity of 8-in lines was about 20,000 b/d, while 12-in lines handled 60,000 b/d. Since the largest refineries operating in that era were designed to handle crude at the rate of approximately 80,000
100,000 b/d, the carrying capacity of the pipelines built by a refiner were carefully gauged to support the refinery with little excess capacity to offer to others (Wolbert, 1979). By the 1870s, a 2000-mile network of small-diameter gathering lines connected the oilproducing areas with regional refineries and storage points on the railroads and rivers where the oil could be shipped to refineries via railcars or ships and barges. Typical crude oil trunk lines were constructed of 18-ft sections of lap-welded wrought-iron pipe 5 or 6 in in diameter joined with tapered, threaded joints manufactured specifically for pipeline

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service. The pipe was generally buried 2 or 3 ft below the ground surface. Worthingtontype pumps were used as the motive power for the lines, and the pumps were powered by steam generated by coal-fired boilers. Pump stations were spaced as needed to maintain the flow of oil over the terrain crossed by the lines. At the pump stations, oil was withdrawn from the lines and passed through riveted steel receiving tanks some of which were 90 ft in diameter and 30 ft high holding about 35,000 barrels (Scientific American, 1892). Diesel-powered pumps began to replace steam power around 1913
14 (Williamson et al., 1963). It was not until May 1879 that the Tidewater Pipe Company, Ltd. began operation of the first long-distance crude oil pipeline covering the 100 mi between Coryville and Williamsport, PA, to connect with the Reading Railroad. The line was constructed of 6-in wrought-iron pipe laid on the surface of the ground (except when crossing cultivated land) and relied on only two pumping stations, one at Coryville and the other near Coudersport. The expansion of the oil under the hot summer sun caused the line to shift as much as 15
20 ft from its intended position, knocking over telegraph poles and small trees, but no serious breaks occurred. In the spring of 1880, Tidewater buried the entire line (Williamson and Daum, 1959). The success of the Tidewater pipeline set the pattern for the construction of other longdistance crude oil “trunk” lines which sprang unpin the early 1880s connecting the oil regions of PA with refining centers in Cleveland, Pittsburg, Buffalo, Philadelphia, Bayonne, and New York City (Williamson and Daum, 1959). By 1905, the oil fields in the Oil Regions of Appalachia stretching from Wellsville, New York, through western PA, West Virginia, eastern Ohio, Kentucky, and Tennessee were becoming depleted. The new oil fields discovered during the early 1900s in Ohio, Indiana, Illinois, southeastern Kansas, northeastern Oklahoma, and eastern Texas were quickly connected by trunk lines to the eastern refining centers as well as the new western refineries in Lima, Ohio; Whiting, Indiana; Sugar Creek, Missouri; and Neodesha, Kansas (Johnson, 1967). The proximity of the prolific Spindle Top Field to the Gulf coast made the area around Houston, Port Arthur and Beaumont, Texas, and Baton Rouge, Louisiana into a petroleum refining center. Regional pipelines were built to carry crude oil the relatively short distances to the Gulf coast refineries (Johnson, 1967). The oil tanker ships operating from the Gulf coast ports competed for and obtained control of most of the long-distance oil transport to the refineries and markets along the eastern seaboard by the mid-1920s (Williamson et al., 1963; Johnson, 1967).

5.3.4 1926
50 The following important events took place during this era: 1. 1942. Plantation Pipeline was completed from Gulf Coast to northeast. 2. 1942. German submarines began sinking crude oil tankers destined for refineries in the northeast. 3. 1942
1943. War emergency pipelines were built: a. Big Inch b. Little Inch 4. 1947. Big Inch and Little Inch were sold to Texas.

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Eastern Transmission converted to gas 1. Multiple oil and gas pipelines constructed post
World War II (WW II) The following business/engineering landmarks took place during this era: 1. 1927. Missouri
Kansas Pipe Line Corporation formed by a group of entrepreneurs. It later became Mo-Kan and then Panhandle Eastern. 2. 1930. Four natural gas companies controlled almost 60% of US gas transmission pipeline mileage. 3. 1931. People’s Gas Light Company (Chicago) began the first major marketing of natural gas for home heating. 4. 1932. More than 80% of US gas sales by volume are natural gas versus manufactured gas. 5. 1947. Minneapolis Gas Light Co. switched entirely from manufactured gas to natural gas. This was the era both gas and oil regulations were implemented in large numbers: 1. 2. 3. 4. 5. 6. 7. 8. 9.

1928. US Senate directs the Federal Trade Commission to investigate utility holding companies. 1935. Public Utility Holding Act Passed. 1935. Federal Power Act Passed. 1935. Federal Trade Commission’s investigation of utility holding companies, comprised of ninety six volumes, published. 1938. Natural Gas Policy Act passed. 1948. United Kingdom passes The Gas Act of 1948 nationalizing the gas industry in the United Kingdom. 1940. ICC established a standard for assessing the reasonableness of oil pipeline. 1941. Federal legislation passed giving oil pipelines the right of eminent domain with the President of the United States decided it was in the interest of national defense. 1941. Consent Decree signed by Justice Department and 20 major oil companies, 52 oil pipeline companies, and 7 affiliates or subsidiaries. This was a busy era for technological breakthroughs. The following events are taken place:

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

1926
50. Technology 1927. Electric flash-welded pipe developed. 1928. First API Standard 5 L for making line pipe appears. 1928. Over 60 coating compounds were in use to coat pipe, protecting it from corrosion. 1933. Most large diameter pipelines are welded with electric arc girth welding. 1933. Ultrasonic testing for use in detecting cracks in metal developed by O. Millhauser. 1935. Publication of first standard code for design of pressure piping. 1942. API Standard 5 L includes hydrostatic testing of pipe. 1942. American standard code for pressure piping appears. 1944. Moody diagram plotted. 1944. Electric flash-welded pipe included in API Standard 5 L. 1948. Radiographic inspection of girth welds is introduced. 1948. Double submerged-arc-welded pipe is introduced. 1948. Standard 5LX introduced.

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Until the 1930s, when large-diameter steel pipe was in widespread use, the carrying capacity of oil pipelines was increased by laying an additional line or lines alongside the original pipe within the same right-of-way. This practice was known as “looping.” The carrying capacity of 8-in lines was about 20,000 b/d, while 12-in lines handled 60,000 b/d. Since the largest refineries operating in that era were designed to handle crude at the rate of approximately 80,000
100,000 b/d, the carrying capacity of the pipelines built by a refiner were carefully gauged to support the refinery with little excess capacity to offer to others (Wolbert, 1979; Willson, 1925). By 1941, just prior to the United States’ entry into WW II, there were about 127,000 mi of oil pipeline in the United States composed of about 63,000 mi of crude oil trunk lines, about 9000 mi of refined product lines, and about 55,000 mi of crude gathering lines (Frey and Ide, 1946). From February through May 1942, 50 oil tankers serving the Atlantic seaboard were sunk by German submarines. The continuing attrition of the tanker fleet by enemy action and the diversion of tankers to serve military operations abroad caused a tremendous increase in the use of pipelines to transport both crude oil and refined products to the east coast which consumed about 40% of the petroleum produced in the United States. In June 1941, before the Pearl Harbor attack, pipelines delivered about 2% of the petroleum needed by the east coast; by April 1945, pipelines carried 40% of this critical supply (Frey and Ide, 1946). The wartime expansion of the pipeline network added more than 11,000 mi of trunk and gathering lines, repurposed over 3000 mi of existing pipelines in new locations and reversed the direction of flow of more than 3000 mi of other lines (Frey and Ide, 1946). One of the pipelines converted from products delivery and reversed in flow direction to convey crude oil to east coast refineries during the war was the Tuscarora pipeline. After the war, it was reconverted and its direction of flow was again reversed to convey gasoline from the coastal refineries to the interior (Johnson, 1967). Noteworthy wartime pipelines owned by the federal government were the “Big Inch” crude oil line, the largest pipeline in the world at that time measuring 24 in in diameter for much of its 1254 mi length; and the “Little Big Inch,” the longest refined products pipeline in the world at 1475 mi of 20-in diameter pipeline (Frey and Ide, 1946). Only during WW II did the federal government finance oil pipeline construction (Johnson, 1967). With the proven success of long, large-diameter crude and refined products pipelines during WW II, the rapid growth in demand for petroleum products in the post
WW II era prompted a great expansion in construction of large pipelines. The number of refined products pipelines increased about 78% from 9000 mi in 1944 to 16,000 mi in 1950. Crude oil trunk lines expanded from about 63,000 mi in 1941 to about 65,000 mi 1950. The postwar increase in the diameter of the crude oil trunk lines, and therefore their carrying capacity, far outweighed the relatively modest increase in mileage (Johnson, 1967) (Tables 5.3 and 5.4).

5.3.5 1951
75 During this era, the following developments took place in terms of pipelines: 1. 1951. 1840-mile long, 30-inch diameter natural gas pipeline built from the Gulf Coast to PA and NY built by Transcontinental. The line operated at 800 psi and had 19 compressor stations. 2. 1955. Over 6000 miles of pipeline are in operation in the USSR.

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TABLE 5.3 Crude and product trunk line mileage by size, 1936, 1941, and 1950. Crude oil lines

Refined product lines

Size

June 30, 1936

May 1, 1941

January 1, 1950

June 30, 1936

January 1, 1950

Below 4 in

1270

1050

1233

162

391

4 in

3990

3590

2768

692

1366

6 in

10,460

12,570

12,254

3781

6696

8 in

27,060

29,380

27,780

4230

9979

10 in

9450

11,710

13,500

68

1628

12 in

5510

6710

9027

68

817

Over 12 in

80

170

4811

0

4

Totals

57,820

65,180

71,373

9001

20,881

TABLE 5.4 Shipments of refined products within the United States (billion ton-miles). 1979

2001

Mode

Shipments

Percent

Shipments

Percent

Pipeline

236.1

44.2

299.1

60.6

Tankers/barges

257.4

48.2

145.9

29.6

Truck

27.8

5.2

29.7

6.0

Railroad

12.9

2.4

18.5

3.8

Total

534.2

100.0

493.2

100.0

From: Federal Trade Commission, 2004. The Petroleum Industry: Mergers, Structural Change, and Antitrust Enforcement. (Original source: Association of Oil Pipelines, 2003. Shifts in Petroleum Transportation. Table 5.4.) FTC, Washington, DC.

3. 1964. Colonial Pipeline begins operations. 4. 1972. Explorer Pipeline begins operations. In terms of technology, the following landmark events took place during this era: 1. 2. 3. 4. 5. 6.

1953. Line pipe Grades X46 and X52 are introduced. 1956. Mill hydrostatic testing to 90% of specified minimum yield strength (SMYS) introduced. 1959. ASA B31.4 appears as a separate code for oil transportation piping systems. 1963. Nondestructive inspection of line pipe under API Specification 5 L begins. 1965. MFL internal inspection introduced to the industry. 1969. Supplemental requirements for toughness testing introduced in API Specification 5 L. During the same era, the following business/technological breakthroughs took place:

1. 1951. New York City begins to receive natural gas in large quantities. 2. 1959. LNG is produced for the first time on an industrial scale in LA. It is transported to United Kingdom by the vessel Methane Pioneer.

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3. 1962. Peoples Gas is able to meet all demands by Chicago residents for natural gas to heat their homes. 4. 1964. Buckeye Pipeline Company is acquired by Penn Central Corporation. 5. Burgeoning post
WW II demand for refined products The following Gas Regulations were introduced: 1. 1954. Supreme Court’s decision in Phillips Petroleum Co. v. Wisconsin (347 U.S. 672 (1954)) gave Freight Pipeline Company (FPC) right to regulate well head price of natural gas. 2. 1965. United Kingdom passes the Gas Act of 1965 empowered the Gas Council to acquire and supply gas to 12 area boards. 3. 1968. Federal Natural Gas Pipeline Safety Act of 1968 passed by Congress. 4. 1973. United Kingdom sets up British Gas, replacing the Gas Councils. 5. 1974. FPC determined that area wide pricing of well head gas rates was unfeasible. The postwar shift to large-diameter pipelines (16-in or larger) was made possible by technological advances in pipe manufacture, pipe laying, pumps and their power sources, and automation of pipeline operations (Johnson, 1967). At least 69 large-diameter crude oil pipeline projects were constructed from 1946 through 1958 covering over17,000 mi (Johnson, 1967). An example of the activity during the postwar period, the Tuscarora line, mentioned above, had been reconverted to refined product shipment after WW II and was rebuilt in 1950 with 10- and 12-in pipe and four new and more efficient pumping stations (Johnson, 1967). During the 1960s, the trend to achieve economies of scale through increased pipeline diameter continued. The Colonial Pipeline Company constructed a product line with diameters ranging from 32 to 36 in between Houston and New York City. The Capline, a 40in crude line from Louisiana to Patoka, Illinois, was also constructed during the 1960s (Kennedy, 1984). The announcement of the TransAlaska Pipeline System (TAPS) in February 1969, a 48in above-ground crude oil pipeline carrying heated oil over 800 mi from Prudhoe Bay to Valdez, Alaska ushered in a new era of pipeline technology. TAPS began operation in July 1977 after overcoming many delays, lawsuits, and political challenges at a total cost of about $9.3 billion, up from the initial estimate of $900 million (Wolbert, 1979).

5.3.6 1975
2000 The following technological breakthroughs took place during this era: 1. 2. 3. 4. 5. 6. 7. 8.

1980: high-resolution smart gauges. 1982: experimental smart pig for crack detection was tested. 1983: API 5 L and 5 LX combined in API 5 L. 1985: Grade X80 line pipe appeared. 2000: minimum level fracture toughness made mandatory in API Specification 5L. Internal inspection technologies improved. Scada and automation became routine. Computational and other leak detection techniques improved.

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The following business-related events took place: 1. 1977: TransAlaska pipeline begins operating, eventually carries 15% of the nation’s crude oil supply (2 million b/d) at its peak. 2. 1986: Buckeye formed as the first publically traded pipeline MLP. 3. 1989: Gasprom formed from USSR Ministry of the Gas Industry. 4. 1991: Transneft formed from Glavtransneft. 5. 1992: Enron Liquids Pipeline LP formed. 6. 1997: KinderMorgan Energy Partners, LP formed. 7. Gas transmission companies work to reinvent themselves following the FERC rulings. The following regulations were introduced during this era: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

1979: 1978: 1978: 1985: 1985: 1986: 1986: 1992: 1999: 2000:

Hazardous liquids pipelines brought under federal regulations. Natural Gas Policy Act (NGPA). Power Plant and Industrial Fuel Use Act. FERC issued Order No. 436. FERC issued Opinion No. 154-B. United Kingdom privatized British Gas. Tax Reform Act of 1986. FERC Order No. 636 issued. FERC Order No. 639 issued. FERC Order No. 637 issued.

It was during this period that environmental awareness came to the forefront of the energy sector. US EPA was created in 1970 during Nixon’s presidency. However, it was in 1980s and 1990s that the petroleum sector was somehow considered to be a threat to the environmental integrity. The US Congress imposed a moratorium on new offshore drilling off the California coast in 1981 in response to public outcry and lingering environmental concerns caused by an oil spill off the coast of Santa Barbara in 1969. Within a few years, the ban was extended to all new leases in US coastal waters, except for parts of the Gulf of Mexico and some waters off the coast of Alaska. This ban continues to the present day. However, existing offshore drilling, from leases before the moratorium and from allowed parts of the Gulf and Alaska, represented about 8% of all US production in 1981. Between increasing production in allowed offshore areas and a drop in overall US production, offshore drilling rose to about 30% of US production in the next three decades. An important event was when the Reagan administration fully deregulated crude prices in 1981, allowing US producers to raise prices to market levels. Non-OPEC production began to outstrip that of OPEC—which hinders the cartel’s influence on oil prices. Global demand began to drop due to high prices and conservation measures, and another oil surplus ensues. By 1982, the United States imported about 28% of its oil, down from more than 45% in 1977. By 1985, US fuel economy averaged for automobiles reach nearly 28 mpg, up from 20 mpg in 1978, and consumer fuel switching for heating and electricity helps lower oil consumption. Oil prices dropped from a yearly average of $35 per barrel in 1981 to less than $15 in 1986. The collapse in price encouraged oil companies to shift to cheaper foreign exploration, and US imports began to steadily rise again

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Antipetroleum agenda took a feverish pitch during the Clinton era. In 1993, the Clinton administration announced a partnership to develop and produce affordable, fuel-efficient, low-emission vehicles. However, inexpensive oil and a booming economy drove upconsumption in the United States. While European and Japanese car companies move ahead with commercialization of the first hybrid passenger vehicle, sales of gas-guzzling sports utility vehicles (SUVs)—considered light trucks and thus exempted from tougher US fuel economy standards—explode. SUVs make up a large part of the fleet of US automakers, garnering significant profits in comparison to smaller, more fuel-efficient cars. Between 1993 and the country’s record demand for oil in 2005, consumption increased by 3.6
20.8 million b/d. Asia’s economic crisis in 1997 caused a drop in demand in what has been a growth region for oil markets. Though OPEC tightened its oil production quota, global prices plunge to below $10 per barrel at the end of 1998, down from nearly $20 per barrel in late 1997. The downturn, plus an increasingly constrained environment for oil concessions globally, encouraged a string of oil mergers among the world’s largest private oil companies, including ones between BP and Amoco (the largest foreign takeover of a US company to date), Exxon and Mobil, and Texaco and Chevron. Accused of stifling competition, these mergers faced political scrutiny in the next decade as US gas prices increased significantly. In February 1999, Hugo Chavez assumed office as president of Venezuela, and embarked on a social revolution that included financing new social programs with the country’s oil revenues. In the following years, the provable reserve of Venezuela would skyrocket, catapulting Venezuela to number one position in that regard. In 1999, Vladimir Putin took office as president of Russia, which has the largest conventional oil reserves outside of OPEC. Both Venezuela and Russia nationalized much of their oil resources and restrict access by international oil companies.

5.3.7 2000
present In 2004, Canada surpassed Saudi Arabia as the largest single exporter of oil to the United States, providing 1.6 million b/d compared to the Saudi’s 1.5 million barrels. A decade before, Canada began investing heavily to develop its oil sands, which requires more money and effort to extract and refine than conventional oil. Many estimate oil sands place the country’s oil reserves second to Saudi Arabia. In 1999, oil sands represented about 15% of total Canadian crude production, but by 2010 oil sand production is nearly half. Still, heavily polluting oil sand production increasingly becomes an environmental concern. Starting from Clinton era all the way through Bush and Obama administration, nonpetroleum resources were introduced. Much of these were subsidized through various grants and tax benefits (Islam, 2014). In 2005, the US Congress passed the Energy Policy Act, which includes new incentives for transportation fuel alternatives and flex-fuel cars as well as new subsidies for domestic oil exploration. The law mandated that 7.5 billion gallons of renewable fuels be blended into gasoline by 2012. In his 2006 State of the Union address, US President George W. Bush said “America is addicted to oil.” The law has been criticized for adding billions in federal subsidies to the oil industry, and subsidies of corn-based biofuel are criticized as a threat to food security and the environment. Some energy experts criticized US tariffs on Brazilian sugarcane ethanol, which is cheaper and more energy efficient to produce.

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TransCanada Corporation proposed the Keystone Pipeline project in February 2005 and began construction in 2008 to convey crude oil from Alberta tar sands into the United States. The first phase of the project, from Hardisty, Alberta, to Wood River and Patoka, Illinois, is about 2100 mi long and went into operation in June 2010. Phase two added a leg from Steele City, Nebraska, to Cushing, Oklahoma, about 290 mi, which went online in February 2011. Phase 3 began operations in January 2014 over an extension of the line connecting Cushing, Oklahoma, to the Nederland, Texas, area. Phase 4, also known as Keystone XL, was proposed in 2008 and consists of a second-line running from Hardisty, Alberta, to Steele City, Nebraska. In 2006, a time of near record-high US oil consumption and imports, oil prices began to rise steadily, topping a record $147 a barrel in the summer of 2008. This translates to gasoline averages above $4 per gallon in much of country. Experts debated the cause of the record prices, blaming it on factors such as the economic rise of China and India, commodity market speculation, and basic issues of supply (Islam et al., 2018). Fuel prices and high food prices began to cause unrest around the world. In the United States, high gas prices in a presidential election year invigorated debate about increasing domestic production, especially ending the moratorium on offshore drilling and in Alaska’s Arctic National Wildlife Reserve. “Drill baby drill” becomes a rallying cry for the Republican Party. Shortly after the global financial crisis begins in 2008, oil prices plummeted. In 2007, Congress passed the Energy Independence and Security Act, which would increase Corporate Average Fuel Economy (CAFE) standards from 27.5 to 35 mpg by 2020, and ends the light truck exclusion. The law also mandates greater production of noncorn-based ethanol, and requires biofuels blended with gasoline and diesel to be at least 20% less in greenhouse gas lifecycle emissions than the petroleum-based fuels. In May 2009, the Obama administration announced accelerated CAFE standards of 39 mpg for cars and 30 mpg for light trucks, which the administration highlighted as part of its climate change policy goals. In the spring of 2010, US President Barack Obama laid out his plans for US energy policy, including supporting more biofuels and opening more US waters to offshore oil drilling. However, in April, a deepwater drilling rig exploded and sank in the Gulf of Mexico, causing a massive, 4-month oil spill. The Obama administration, in response, placed a temporary ban on all new offshore drilling projects in order to review US safety and environmental enforcement. Calls renewed for strengthened measures to reduce US oil consumption, now at less than 19 million b/d, down nearly two million barrels from 2005 record levels. In February 2011, Libya became the first major oil-producing nation to join a spate of popular uprisings in the region, which toppled regimes in Egypt and Tunisia. With the largest reserves in Africa, Libya represents about 2% of global oil production. Global oil prices spike nearly 10% in one day. Though the country does not supply oil to the United States, concerns grew that the situation in Libya and potential unrest in other oilproducing nations could lead to a new global oil crisis. In a March 30 speech, US President Barack Obama says that “We will keep on being a victim to shifts in the oil market until we get serious about a long-term policy for secure, affordable energy.” He pledged to reduce US oil dependence by one-third within a decade. The Obama administration announced it would release 30 million barrels from the US Strategic Petroleum Reserve over 30 days. The US release coincided with the release of another 30 million barrels from the reserves of other members of the IEA. The IEA said “greater tightness in the oil market threatens to undermine the fragile global economic recovery.”

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The coordinated release came after OPEC ministers failed to agree to greater output. The US reserve sale represents the fourth major drawdown since the reserve’s initiation in 1977. US tight oil producers contribute to a global supply glut that puts downward pressure on prices. By November, 2014, crude oil falls below $75 a barrel, down from $110 in June. OPEC members met in Vienna, where, despite opposition from some members who want to cut OPEC oil production to halt the price slide, Saudi Arabia pushed the group to maintain a production target of 30 million b/d. The organization met and regularly exceeds that target, leading to further price declines below $50 a barrel by early 2015, which squeezed the finances of oil-exporting countries and forces unconventional drillers in the United States to curb costs and sharply cut production. On November 6, 2015, President Barack Obama rejected the proposed Keystone XL pipeline, which would have transported more than eight hundred thousand barrels of oil per day from Canada to Texas. Subject to multiple rounds of State Department review since its conception in 2008, supporters said it would have created jobs and enhanced energy security, while opponents worried about potential damage to the environment from spills and increased carbon emissions. Debate over the merits of the cross-border pipeline continued, as TransCanada, the company behind the project, files a lawsuit against the US government charging discriminatory treatment under the North American Free Trade Agreement. Congress voted to lift fourdecade-old restrictions on US crude oil exports, and a shipment immediately left the port of Corpus Christi, Texas, for sale in Europe. The shipment consisted of light sweet crude oil drawn from south Texas’s Eagle Ford shale deposits. Even as the United States continued to import oil, opportunities for exports arose since many of the country’s existing refineries are not optimized to process the type of light crude drawn from shale. November 2016, the Paris Agreement was signed by more than 190 countries, including the United States entered into force. The most ambitious climate accord to date, the agreement required all parties to set targets to reduce greenhouse gas emissions, with the goal of arresting the rise in the average global temperature. Countries also agreed to aim for net-zero carbon emissions by mid-century. The United States pledged to cut its emissions by more than 25% from 2005 levels by 2025, a move that required transitioning away from fossil fuels, including oil. Although the accord does not include enforcement mechanisms, there are periodic performance reviews meant to encourage countries to adopt more ambitious targets. Starting 2017, Trump’s “America First” Energy Plan took hold. After campaigning on a promise to boost US oil production and achieve energy independence, President Donald Trump began rolling back his predecessor’s policies. In June, Trump announced the US withdrawal from the Paris Agreement, which would take effect in November 2020. His administration later scraped Obama’s tougher fuel efficiency standards for cars and trucks, which the EPA said would result in about two billion more barrels of oil consumed. The US fracking boom continued, with the administration leasing four million acres of federal land to fossil fuel companies. Trump also revived the Keystone XL pipeline and, with support from the Republican-controlled Congress, opened the Arctic National Wildlife Refuge (ANWR) in Alaska for oil drilling despite opposition from Democrats, environmental activists, and some Alaska Native groups. Alaskan lawmakers and other Alaska Native groups supported the move due to the expected revenue and job growth. As discussed in Chapter 1, the Trump golden era (2017
19) represented the most prosperous phase in US energy history. Then came the COVID-19 pandemic. Starting in March 2020,

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the world was rocked by the emergence of a new coronavirus disease, COVID-19, that quickly becomes a global pandemic. Response measures, including stay-at-home orders, triggered a sharp drop in the demand for oil. Falling oil prices create a rift within OPEC and lead to a price war between Saudi Arabia and Russia, with Riyadh ramping up production to further slash prices in an effort to force Moscow to the table. Oil prices hit rock bottom; in April, a major benchmark price for US crude oil briefly falls below zero for the first time in history. After Whiting Petroleum Corporation, a major US producer, declared bankruptcy, President Trump attempted to broker an OPEC deal to prevent further damage to the US industry. After Trump intervened, OPEC and Russia agreed to curb production and raise prices. Then, United States and the world entered the President Joe Biden regime. He rejoined the Paris Agreement and pledged to cut US emissions by at least 50% of 2005 levels by 2030—and achieve net-zero emissions by 2050. To reach that goal, Biden called for a return to higher fuel efficiency standards for cars and trucks, as well as measures to spur the use of electric vehicles, among other proposals. Biden canceled the Keystone XL pipeline and suspended drilling leases in the ANWR. However, approval for drilling on other federal lands continued at a record pace. As the pandemic abated in the United States, demand for oil rebounded and gas prices surged to a 7-year high. Then came the Russia’s War With Ukraine. Russia’s invasion of Ukraine caused turmoil in global oil markets. Biden blocked US imports of oil from Russia, and Western sanctions caused energy companies to withdraw from the country. Oil prices, already rising in the wake of the pandemic, surged to their highest level since 2008. In response to record gasoline prices, US lawmakers on both sides of the aisle called for boosting domestic oil production, though some in Congress urged a quicker transition to renewable energy. The United States and other members of the IEA announced plans to collectively release sixty million barrels of oil from strategic reserves. Meanwhile, the Biden administration considers smoothing rocky relations with Iran, Saudi Arabia, and Venezuela in the hope that those countries will supply more oil. Senior US officials travel to Caracas for the first time since 2019, and the Biden administration pushes to finalize negotiations on reviving the 2015 Iran nuclear agreement and lifting US sanctions on Tehran.

5.4 Heavy crude oil pipelines Heavy crude oil is highly viscous oil that cannot easily flow from production wells under normal reservoir conditions. However, the term “heavy” does not imply viscosity and refers to the fact that these oils have density or specific gravity is higher than that of light crude oil. Heavy crude oil has been defined as any liquid petroleum with an API gravity less than 20 degrees. Transporting heavy crude oil is a challenge because of the high resistance offered by this type of oil. The high viscosity (103
106 cP) and low API gravity (heavy oil less than 20 API and extra-heavy oil less than 10 API) of such oils are due to the high presence of asphaltenes as well as a relative low proportion of low molecular weight compounds, which represent a lack of light ends. Heavy and extra-heavy crude oils may also have high contents of sulfur, salts, and metals like nickel and vanadium. Table 5.5 lists some of the characteristics of heavy oils. Pipelining of heavy oil presents problems such as instability of asphaltenes,

Pipelines

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5.4 Heavy crude oil pipelines

TABLE 5.5 Properties and composition of medium, heavy, and extra-heavy Mexican crude oil. Mexican crude oils Parameter

Medium

Heavy

Extra-heavy

API gravity

21.27

11.90

9.17

Molecular weight (g/mol)

314.8

486

507.8

Sulfur content (%)

3.40

5.02

4.80

Water content (%)

1.80

0.05

,0.05

Saturates

26.53

7.94

15.00

Aromatics

14.74

5.28

19.11

Resins

47.60

70.93

46.78

Asphaltenes (from n-C7)

11.13

15.85

19.11

SARA analysis

SARA, Saturates, Asphaltenes, Resins and Aromatics.

paraffin precipitation, and high viscosity that causes multiphase flow, clogging of pipes, and high-pressure drops, and production stops. Petroleum crudes are a complex organic mixture of several hydrocarbon components, such as saturates (S), aromatics (A), resins (R), and asphaltenes (A). The viscosity of the oil is intricately related to the chemical structure and composition of these polar (resins and asphaltene) and nonpolar (saturates and aromatics) components. The presence of heteroatoms (N, S, and O) and metals (Ni, Fe, and V) make asphaltene the most polar polycyclic aromatic hydrocarbon (PAH), which leads to its self-association with the formation of a viscoelastic network of nanoaggregates resulting in increased viscosity (Anto et al., 2020). The presence of strong C
S and C 5 S bonds in the crude oil components can also contribute to the increase in the crude oil viscosity. As a result, resistance to flow through pipelines occurs. Typically, this resistance can be due to high viscosity or the presence of wax under flow conditions. In petroleum technology term, it means as follows: 1. High pour point or high wax content. 2. High viscosity under standard conditions. The pour point of a liquid is the temperature below which the liquid loses its flow characteristics. It is the bifurcation point below which a fluid ceases to flow with gravitation forces (Steven et al., 2015). This point usually is high if the crude oil contains large amount of paraffin. Wax deposition is one of the chronic problems in the petroleum industry. The various crude oils present in the world contain wax contents of upto 32.5% (Rehan et al., 2016). Paraffin waxes consist of straight chain saturated hydrocarbons with carbons atoms ranging from C18 to C36. Paraffin wax consists mostly with normal paraffin content (80%
90%), while, the rest consists of branched paraffins (iso-paraffins) and cycloparaffins. The sources of higher molecular weight waxes in oils have not yet been proven and are under exploration. Waxes may precipitate as the temperature decreases and a solid phase may arise due to their low

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TABLE 5.6 Crude oil composition and their properties. Crude oil sample

API gravity

Pour point ( C)

Saturates (%)

Aromatics (%)

Resins (%)

Asphaltene (%)

Procedure loss (%)

BK

32.08

35.8

48

25

12.06

10

4.94

PK

40.02

43.3

50.58

21.98

8.56

9.84

9.03

From Anto, et al., 2020. Nanoparticles as flow improver of petroleum crudes: study on temperature-dependent steady-state and dynamic rheological behavior of crude oils. Fuel 275, 117873. Available from: https://doi.org/10.1016/j.fuel.2020.117873.

solubility. For instance, paraffinic waxes can precipitate out when temperature decreases during oil production, transportation through pipelines, and oil storage. The API gravity and pour-point of both the crude oil samples are given in Table 5.6. Both the API gravity and pour point of sample BK is lower (32, 35.8 C) than that of the sample PK (40, 43.3 C). The high viscosity of 103
106 cP and the lower API gravity (less than 20 for heavy oil and 10 for extra heavy oil) are mainly due to the high content of high molecular weight components such as waxes, asphaltenes, and resins. Also, the presence of heteroatoms and metals makes asphaltene the most polar polycyclic aromatic hydrocarbon, leading to its self-association with the formation of a viscoelastic network of nanoaggregates resulting in an increase in viscosity (Taborda et al., 2017a,b; Anto et al., 2020). As shown in Hagen
Poiseuille equation below, viscosity affects the overall pressure drop directly. This is why it is important to track viscosity of the effluent. Δp 5

8μLQ 8πμLQ 5 πR4 A2

(5.1)

where Δp is the pressure difference between the two ends, L is the length of pipe, μ is the dynamic viscosity, Q is the volumetric flow rate, R is the pipe radius, and A is the cross section of pipe. In the above equation, the dependence of pressure drop on R4 is noteworthy. In terms of pipelining, this equation shows the radical improvement in flow conditions for increased diameter of the pipeline. Fig. 5.13 shows the relationship between flow rate and diameter. Viscosity is a strong function of temperature and for non-Newtonian fluid it is also a function of strain. Although, most academic calculations consider a linear relationship between stress and stress, thus constant viscosity for a given time, it is in fact an intricate function of strain. Fig. 5.6 shows how Newtonian fluid behavior departs from non-Newtonian fluid behavior (Fig. 5.14). Typically, crude oil is a mixture of various ingredients, such as air, water, salt, and polymers. In addition, crude oil itself is not homogeneous. As such, crude oil, as transported in the pipeline is not Newtonian. With non-Newtonian fluids, the use of a viscometer results in uneven, and nonrepeatable measurements that overestimates viscosity with slow moving sensors or underestimates with vibrating or fast moving rotating sensors. In a laboratory, the following methods are used to measure instantaneous viscosity: 1. Orifice viscometers. Orifice viscometers include the different varieties of cup viscometers. As they function using gravity, the viscosity measured is kinematic viscosity.

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Flow Rate (cc/s) 1.5E–5 1.25E–5

FIGURE 5.13

Flow rate versus diameter.

P = 50 mmHg n = 0.05 P L = 0.5 cm

1.0E–5 0.75E–5 0.5E–5 0.25E–5 10

20

30

40

Diameter (0. 001 mm)

FIGURE 5.14 Stress
strain relationship for various fluids.

2. Capillary viscometers. Capillary viscometers use gravity to measure how long it takes a fluid sample to travel the length of a tube. They also measure kinematic viscosity. 3. Falling piston viscometers. Falling piston viscometers use the force created by a falling piston to measure viscosity. They measure dynamic viscosity, because stress is applied to the fluid. 4. Rotational viscometers. A rotational viscometer measures how much torque is required to turn a spindle immersed in a fluid. The spindle applies stress to the fluid, resulting in a measurement of dynamic viscosity. 5. Falling ball viscometers. A falling ball viscometer measures the force required for a ball to fall through a fluid. The ball applies stress to the fluid, giving a measurement of dynamic viscosity. Patented in 1932 by Fritz Ho¨ppler, the falling ball viscometer was actually the first type of viscometer to measure dynamic viscosity. 6. Vibrational viscometers. Vibrational viscometers measure the resistance of a fluid to vibration. Since the vibration constitutes a force being applied to the fluid, these viscometers measure dynamic viscosity.

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Recently, a new viscometer was introduced that is applicable to both Newtonian and non-Newtonian fluid (Liu et al., 2021a
c). The established measurement techniques of rheological properties include the following four methods: (1) online rotational Couette viscometer, (2) pipe viscometer, (3) mathematical or artificial intelligence (AI) model based on a Marsh funnel, and (4) tuning fork technology (Liu et al., 2021a
c). Fig. 5.15 shows a schematic example of the pipe viscometer. Fig. 5.16 shows the velocity profile under laminar flow conditions (Table 5.7). Differential pressure sensor Pump

'P

Flowmeter

Drilling fluid

'L

FIGURE 5.15

A schematic example of the pipe viscometer.

FIGURE 5.16

Velocity profile in laminar flow.

TABLE 5.7 Comparison among various techniques and their relative cost. Technique Working principle

Advantages

Limitations

Cost

Online Concentric cylinder Couette (Couette flow) viscometer

Similar to API standards

Solids less than 1 mm; solids settling; easily blocked; frequent maintenance

High

Pipe Pipe pressure difference Automation; not susceptible to viscometer under various flow blockage; obtains other parameters rates by adding other sensors to the pipe

Large size

High

Based on Marsh funnel

Manual test, complex theoretical model

Low

Marsh funnel time, mud Simple test tool weight, solid content

Acoustic Acoustic characteristics technology of sound waves propagating in drilling fluid

Simple installation; not susceptible to blockage; density and viscosity can be measured

From Liu et al. (2021a
c).

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Manual calibration; Medium complex theoretical model

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The online Couette viscometer is the most similar to the API standard measurement method. However, the gap between the rotor and the stator is narrow, and the diameter of solids must less than 1 mm. Solid or gels particles may be sedimented in the viscometer, so the online Couette viscometer is easily plugged. It is inconvenient to use and requires regular cleaning and maintenance. This viscometer is suitable for drilling fluids with low viscosity and low solid content. Compared with the online Couette viscometer, the pipe viscometer provides better automatic measurement technology. The solid and gel particles in the drilling fluid will not settle in the pipe. By adding additional sensors to the pipe, additional variables can be obtained such as fluid density, temperature, critical Reynolds number, and real-time friction coefficient. However, it cannot measure the 10 second and 10 minutes gel strength. Compared with the pipe viscometer, the helical pipe viscometer has obvious advantages, having a compact size and more general friction pressure loss curve. At the same time, the helical pipe increases the friction pressure loss and delayed flow state transition, so the helical pipe viscometer can be used to collect more data in the laminar flow state, thereby improving the accuracy of low shear rheological parameter estimation. However, the theoretical basis for the helical pipe viscometer is still under development. AI technology is the cheapest method, because only the Marsh funnel is needed, and the mud balance and solid content meter may be added optionally. Although the test of the Marsh funnel, density, and sand content was simple and quick, it still required manual testing. The neural network model was different when the drilling system was different. One AI method can be used in wells which are in the same block or in the same drilling system. The test results of the tuning fork technology were Marsh funnel viscosity and density, which can be combined with AI technology to form an automatic online measurement of drilling fluid rheological properties. Recently, Hussain et al. (2013) introduced a novel viscometer that can be used online and is applicable to both Newtonian and non-Newtonian fluids. Their invention relates to a Coriolis1 mass flowmeter with a measuring tube that can be excited into oscillation, an oscillation driver and/or an oscillation sensor, wherein the oscillation. driver and/or the oscillation sensor has a permanent magnet. It is the object of the invention to specify such a Coriolis mass flowmeter that has an oscillation driver and/or an oscillation sensor having an effectively useful permanent magnet. The Coriolis effect is achieved through the permanent magnet is provided in a magnet holder. The permanent magnet is inserted in a device provided solely for its mounting, namely the magnet holder. For this reason, the permanent magnet is at least partially enclosed by the magnet holder according to the invention, which acts as protection against external influences, such as bumping. Furthermore, the fixation of the permanent magnet is realized by the magnet holder at least partially enclosing it, so that the permanent magnet does not need to be provided with a hole for the mounting screw. Mass flowmeters that work according to the Coriolis principle generally have at least one oscillation driver that excites the measuring tube into oscillation as well as two oscillation sensors, which register the achieved oscillation of the measuring tube. The determination of the mass flow is then definable, for example, using the phase shift of the achieved oscillations between the two oscillation sensors. 1

It is an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic weather systems.

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The viscosity of a Newtonian fluid does not change with flow. A viscometer can be used to measure the viscosity of such fluid, with certain accuracy. Still the oil viscosity is sensitive to the temperature, and temperature measurement must be very accurate in order to maintain a good viscosity measurement. A 0.1 C uncertainty on temperature can generate over 2% of error on a viscosity measurement. With a non-Newtonian fluid, not only its viscosity depends on temperature, but also it varies with the flow. In such case, a viscosity measurement must be referred to a temperature and some parameter that describes well enough the flow condition of measurement. In a pipe flow, this is the shear rate. A simple viscometer does not provide any shear rate reference with a viscosity measurement. It provides for a rotational speed, a frequency of oscillation but nothing directly related to shear rate. In other words, it is like referring a measurement to the surrounding humidity rather than temperature. A temperature increase gives more freedom for the molecules to move between each others. As a consequence, the bulk resistance to flow is decreased. This is what is illustrated in Fig. 5.17. This graph represents viscosity versus shear rate for a heavy oil. It shows how its viscosity changes with temperature. For the 26 C curve, all the measuring points remain on a same horizontal line, so there is no dependence to flow. But for the lower temperature, at 22 C, the effect of shear rate is quite important. In a general way, an oil has a critical temperature separating a Newtonian versus non-Newtonian behavior. In the case illustrated bellow, this critical temperature is at 24 C. Depending on the location in the process, the oil may contain some quantities of water or gas. Also, crude oil is in general acidic. As such, any crude oil is prone to producing emulsions. Emulsions are formed due to the physiochemical characteristics of the brine and the oil. The emulsions exhibit an increase in viscosity in comparison to the oil and it is strongly related to the water content and disperse phase morphology, this effect implies a decrease in the oil production due to oil mobility reduction, problems in the transportation, damage to the formation, among others. This effect is more pronounced for heavy oil, for which viscosity rises so much that the pumping may be obstructed (CisnerosDe´vora et al., 2019). In this, the disperse phase morphology directly relates with viscosity and the presence of a mechanically irreducible. In the crude oil, the components responsible to give stability to these emulsions are mainly the asphaltenes whereas in the brines are the divalent ions, both affected by the presence of acids. In this process, the molecular FIGURE 5.17 Dependence of viscosity on shear rate and temperature. Source: From Ghannam, M.T. et al., 2012, Rheological properties of heavy & light crude oil mixtures for improving flowability, Journal of Petroleum Science and Engineering 81, Jan. https://doi. org/10.1016/j.petrol.2011.12.024.

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FIGURE 5.18 Formation of emulsions in a crude oil (Cisneros-De´vora et al., 2019).

structure of asphaltenes, oil acidity and calcium chloride all have an effect on the stability of water-in-oil (W/O) emulsions. Also, the presence of salts and an acidic environment promotes the increase of the viscosity and the formation of stable emulsions. Fig. 5.18 shows the schematic of this process. The main compounds responsible for acidity in crude oils are naphthenic acids, though other heteroatomic species are also acidic, particularly sulfur-containing compounds. Total acid number (TAN) measured in mg KOH/g-sample is the most used unit of acidity. A TAN threshold of 0.5 mg KOH/g has been established as the minimum TAN of a category of crude oils known as high-acid (or TAN) crude. These crude oils cause a variety of problems in the whole value chain of the oil industry. Ramirez-Corredores (2017) reviewed the knowledge associated with the origin, isolation, identification, characterization, properties, and problems derived and caused by acid compounds and mostly by naphthenic acids. The viscosity of an emulsion depends on three factors: 1. The viscosity of the oil (the continuous phase). 2. The size of the droplets of air or water. 3. The surfactant agent acting at the interface between the different phases. Crude oil, itself is often acidic, hence surface active. Also, often additives, such as, the drag reducers change the fluid properties in order to minimize the turbulence, mainly in the cross flow direction, in order to reduce the pressure drop. This is achieved by changing the rheological properties of the oil based mixture, and making it non-Newtonian. This change can be invoked with temperature change or chemical additives. For the transportation of heavy crude oil with a viscosity between 200 and 400 cP at room temperature, various methods have been proposed and used by the petroleum industries. Some of the methods are as follows: 1. 2. 3. 4. 5. 6. 7.

Dilution with lighter petroleum or organic solvents. Forming of heavy crude oil emulsions in water. Heating heavy crude oil and pipelines. Electrically heated submarine pipelines. The use of pour point depressants (PPDs). The application of drag reduction additives. Core annulus flow (CAF) and partial upgrading.

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At present, there are three general approaches for transportation of heavy and extra heavy oil: viscosity reduction, drag minimization, and in situ oil upgrading (Martı´nez-Palou et al., 2011). Reduction of oil viscosity can be accomplished by (1) dilution with other substances, (2) formation of an oil-in-water (O/W)emulsion, (3) increasing and/or conserving oil’s temperature, and/or (4) depressing crude oil’s pour point. The second alternative consists to reduce friction between the pipeline and the heavy oil through (1) the addition of substances that reduce drag inside the pipeline (drag reducing additives) and/or (2) developing a different type of flow (annular and slurry). Finally, physicochemical upgrading of heavy oil produces a synthetic fuel or syncrude with higher API gravity, minor viscosity, and less content of pollutants as sulfur and nitrogen. The combination of two or more of these approaches may be used to resolve or improve pipelining of heavy and extra-heavy crude oil since there are not unique technological solutions. Martı´nez-Palou et al. (2011) detailed the first two options, while Rana et al. (2017) reviewed the oil upgrading option. Fig. 5.19 shows the viscosity
temperature curves of three oils from the Brookfield rotational viscometer. As shown, oil #13041 is the ordinary heavy oil of type II, and the other ones (#13161 and #13121) are the extra heavy oil type. It is observed that the viscosity
temperature curves of oil #13161 and #13121 have the obvious property of two straight lines with the different slopes on the semilog coordinate. The first-line slope is much higher than that of the second line. The intersection point of these two lines is defined as the turning point of temperature. The turning point relates to a change in the rheological property of the oil. It is extremely important to measure viscosity within a pipe line. Such measurements are necessary for quantifying the quantity of oil transported when diluted, or just making sure that it does not exceed the pumping capacity. For heavy oil, the crude oil viscosity becomes a liability in terms of power needed for the fluid to flow. Recently, thermal data on crude oil in presence of nanoparticles were generated by Anto et al. (2020). Steady-state viscosity measurements for nanoparticle-free and nanoparticle-added crude oils (0.3% silica and alumina) were performed at different temperatures (cooling from 70 C to 40 C) and plotted in Fig. 5.20. The shear rate range of 1
40/s was selected for the FIGURE 5.19 Viscosity
temperature curves of several heavy crude oils. Source: From Dong, X. et al., 2013. Non-Newtonian flow characterization of heavy crude oil in porous media. J. Petrol. Explor. Prod. Technol. 3, 43
53.

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FIGURE 5.20 Viscosity variation of nanoparticle-free crude oil samples and nanoparticle-added crudes with temperature at different shear-rate range. Left panel (A1, A2, A3 and A4) represents sample BK and right panel (B1, B2, B3, and B4) represents sample PK (B_RC, nanoparticle-free crude oil BK; P_RC, nanoparticle-free crude oil PK; SNP, silica nanoparticle; ANP, alumina nanoparticle). Source: From Anto, et al., 2020. Nanoparticles as flow improver of petroleum crudes: study on temperature-dependent steady-state and dynamic rheological behavior of crude oils. Fuel 275, 117873. Available from: https://doi.org/10.1016/j.fuel.2020.117873.

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experiments because up to the shear rate of 40/s, the effect of shear as well as temperature is prominent and with further increase in the shear rate, the viscosity remains nearly constant (due to the prominence of shear rate). It was observed that for sample BK, the viscosity increased at a slow rate upto the temperature of 50 C and with a further decrease in temperature, the viscosity abruptly increased in all the observed shear rates (Fig. 5.20-A1
A4). It was also observed that there was a maximum decrease in the viscosity of the crude oil after the addition of silica nanoparticles followed by the alumina nanoparticles (Fig. 5.20-A1
A4). A similar trend is observed for sample PK, although the viscosity is higher than BK crude at all corresponding shear rate range (Fig. 5.20-B1
B4). The addition of nanoparticles reduces the viscosity of the nanoparticle-free crude. One important consideration of heavy oil transportation is whenever the temperature is below the pour point, the heavy oil completely gels and causes serious transportation problems, particularly in cold offshore conditions where deposits of waxes and asphaltenes on the internal surfaces of pipelines reduce the effective diameter of the flow and eventually clog them, creating a huge pressure drop on the pipeline (Souas et al., 2021). However, knowledge of the rheological behavior of crude oil is necessary to understand the relationship between microstructures and their crystallization mechanisms. Knowledge of the effect of different parameters on the rheological behavior is very important for designing the flow parameters for crude oil pipeline transportation (Kumar et al., 2017). Measurements are generally made with an advanced rheometer in steady shear and oscillatory mode which are expressed by plotting the variations in apparent viscosity and shear stress as a function of temperature. In crude oil a high pour point is generally associated with a high paraffin content, typically found in crude deriving from a larger proportion of plant material. That type of crude oil is mainly derived from a kerogen Type III. The high API gravity nature of oil is a result of high ratio of aromatics and naphthenes to linear alkanes and high levels of NSOs (nitrogen, sulfur, oxygen, and heavy metals). Heavy oil has a higher percentage of compounds with over 60 carbon atoms and hence a high boiling point and molecular weight. The process of solvent dewaxing is used to remove wax from either distillate or residual feedstocks at any stage in the refining process. The solvents used, methyl-ethyl ketone and toluene, can then be separated from dewaxed oil filtrate stream by membrane process and recycled back to be used again in solvent dewaxing process. Heavy crude oil pipelines are special types of production pipelines transporting crude oils either with very high pour points (at pour point liquid looses its flow characteristics) or with high wax contents. They normally transport crude oil for a short distance, mostly from offshore production platforms to oil processing onshore facilities. Before entering the pipelines, the crude oils are heated to reduce their viscosity. During transportation, wax deposits in the pipeline due to dissipation of heat into the ocean water. Deposition of wax decreases the efficiency of the pipelines and, in extreme conditions, flow may stop. The construction materials of heavy crude oil pipelines are similar to those of production pipelines. Because of the higher viscosity of heavy crudes, however, special approaches are taken to operate these pipelines. Some of the unique features in operating heavy crude oil pipelines include insulation of the external surface of the pipelines with polyurethane foam to retain the heat, and inclusion of a high-density polyethylene outer shield to minimize water entry into the polyurethane foam; heating the crude oil to higher temperatures at the inlet and transporting to

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the destination before it cools below its pour point; mixing of the heavy crude oils with diluents or less waxy crude oil to decrease their pour point; emulsification of the heavy crude oil with water; injection of water to form a layer between the pipe wall and the crude; installation of heaters along the pipeline to maintain the temperature of the pipe above the pour point of the crude oil; injection of paraffin inhibitors into the crude oil to prevent the wax content. In general, all corrosion mechanisms discussed in production pipelines can occur in the heavy crude oil pipelines, but the corrosion conditions of heavy crude oil pipelines are less severe than those of traditional production pipelines. The mildly corrosive conditions in heavy crude oil pipelines are primarily due to the tendency of heavy crude oils to wet the metal surface. However, the water-soluble components of the heavy crude oil may affect its corrosivity.

5.4.1 Viscosity reduction 5.4.1.1 Dilution of heavy and extra-heavy crude oils Dilution is one of the oldest methods for reducing the viscosity of heavy oils. While such reduction during an enhanced oil recovery process is not economical, it is the most useful for refining and pipelining. Since the 1930s, dilution consists in the addition to heavy oil of lighter liquid hydrocarbons, typically condensates from natural gas production or lighter crude oils are used. This is an effective option to reduce oil viscosity and facilitate its mobility in the pipeline since a ratio of 20%
30% of solvent is often enough to avoid high-pressure drops or the need for high temperatures. Also, diluting the crude may facilitate certain operations such as dehydration and desalting. Lighter petroleum components can bring down the water content in the pipeline specifications and prevent the flow assurance problems that are related to water. Among the commercially available glycols, triethylene glycol (TEG) has been widely consumed in the oil and gas industries as the conventional absorbent and received the universal acceptance as the cost-effective and economical liquid desiccant. Monoethylene glycol (MEG) and diethylene glycol (DEG) were also commonly used in dehydration processes. Compared to MEG and DEG, TEG has proven superior performance with lower vapor pressure, lower operating costs, and higher hygroscopic properties. Similar actions are affected in presence of petroleum solvents. Salts in crude oil are mainly in the form of magnesium, calcium, and sodium chlorides, sodium chloride being the most abundant. These salts can be found in two forms: dissolved in emulsified water droplets in the crude oil, as a W/O emulsion, or crystallized and suspended solids. The negative effect of these salts in downstream processes can be summarized as follows: salt deposit formation as scales where water-to-steam phase change takes place and corrosion by hydrochloric acid formation. Hydrochloric acid is formed by the decomposition of magnesium and calcium chloride at high temperatures (about 350 C) as follows (Fahim et al., 2010a,b): CaCl2 1 2H2 O-CaðOHÞ2 1 2HCl MgCl2 1 2H2 O-MgðOHÞ2 1 2HCl

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In addition, other metals in inorganic compounds present in reservoir dirt and sand produce catalyst poisoning in downstream processes such as hydrotreaters and cat crackers because of they are chemically adsorbed on the catalyst surface. The petroleum solvent alters solubility parameters of the salt, thus helping with the transportation (Long et al., 2012). While dilution is effective and widely used, they are useful only when condensates or lighter crude oil is available to transport heavy and extra-heavy oils by pipeline. Even then, it may require substantial investments in pumping and pipelines due to the increase of the transport volume and the need to separate at some point the solvent, processes it and subsequently returns it to the oil production site. Also, the dilution option has some challenges since any change in oil composition may affect the required oil
solvent ratio. Then, it is important to predetermine the ratio of solvent to heavy oil since simple mixing rules do not directly apply and careful attention should be paid to the reliable measurement of crude oil and mixtures’ viscosity and compatibility. Finally, it is commonly understood that in order to meet pipeline viscosity specifications, more diluent is used than necessary to meet the API gravity specification. The process is particularly challenging in the presence of asphaltene or/ and wax as the stability of them can be altered in presence of solvents, thus risking clogging of the pipeline (Zaman et al., 2004). Yaghi and Al-Bemani (2002) found that a mixture of extra heavy and light oils (7:3) possesses a viscosity of around 1000 and 300 cP at 303 or 323K, respectively; when compared to the original heavy oil (15,000 cP at 293K). Here, the dilution using a light crude oil (29 API) and the need for heating to 323K may make this approach rather expensive. In our experience, heavy oil dilution indeed reduces viscosity but other issues remain unsolved or become more important like asphaltene and paraffin deposition. Van den Bosch and Schrijvers (2006) presented a combined dilution
upgrading method based in the in situ production of the solvent by separation, distillation and thermal cracking of a part of the heavy oil feed to produce one or more light fractions and one or more heavy fractions. The feed of heavy oil is split in two, one part is sent to the aforementioned process and the other is diluted with the mix of all light fractions of the processed heavy oil while the obtained heavy fractions are used to generate heat and/or power. Thus a pipelinetransportable syncrude is formed which is easier to refine and presents less stability problems than completely upgraded syncrudes. Their novel technique has the following steps: 1. Dividing the bitumen feed into two fractions, the first fraction comprising between 20 and 80 wt.% of the feed, the second fraction comprising between 80 and 20 wt.% of the total feed, (the two fraction together forming 100 wt.% of the feed) 2. Distillation of the first fraction obtained in step (1) (preferably under vacuum) into a light fraction boiling below 380 C. (preferably the 450 C. fraction, more preferably the 510 C. fraction) and a residual fraction. 3. Thermal cracking of (at least part of or preferably all of) the residual fraction obtained in the distillation process described in step (2). 4. Distillation of the product obtained in step (3) into one or more light fractions (boiling below 350 C), optionally one or more intermediate fractions (boiling between 350 C and 510 C) and a heavy fraction (boiling above at least 350 C). 5. Combining the second fraction obtained in step (1), the light fraction obtained in step (2) and the light fraction(s) obtained in step (4) to obtain a pipeline-transportable crude oil. 6. Using heavy fraction obtained in step (4) for the generation of power and/or heat.

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Similar process was previously used by Myers et al. (2000, 2001). In this process, a bitumen is rendered pipelineable by partially hydroconverting the bitumen and then adding sufficient diluent to the partially hydroconverted bitumen to provide a mixture having an API gravity at 15 C of at least 19 and a viscosity at 40 C in the range of about 35 to about 60 cP. Iqbal and Floyd (2010) patented a novel process for the upgrading of heavy oils and bitumens, where the total feed to the process can include heavy oil or bitumen, water, and diluent. The process can include the steps of solvent deasphalting the total feed to recover an asphaltene fraction, a deasphalted oil fraction essentially free of asphaltenes, a water fraction, and a solvent fraction. The process allows removal of salts from the heavy oils and bitumens either into the aqueous products or with the asphaltene product. The various stages involved are as follows: 1. Diluting the heavy oil or bitumen at a production site with a diluent comprising a hydrocarbon having from 3 to 8 carbon atoms to form a mixture. 2. Transporting the mixture from the production site to a solvent deasphalting unit. 3. Deasphalting the mixture in the solvent deasphalting unit to recover an asphaltene fraction, a deasphalted oil fraction essentially free of asphaltenes, and a solvent fraction. 4. Separating water and salts from the asphaltene fraction, the deasphalted oil fraction, and the solvent fraction at the solvent deasphalting unit; conveying at least a portion of the solvent fraction to the production site to dilute the heavy oil or bitumen and form the mixture. The patent also includes the following additional claims: 5. The process of claim 1 wherein the heavy oil or bitumen has an API gravity from 2 to 15. 6. The process of claim 1 wherein the heavy oil or bitumen has a TAN between 0.5 and 6. 7. The process of claim 1 wherein the heavy oil or bitumen has a basic sediment and water content from 0.1 to 6 weight percent. 8. The process of claim 1 further comprising injecting water into the mixture at or upstream from the solvent deasphalting unit to facilitate removal of chloride salts. 9. The process of claim 1 wherein the solvent deasphalting of the mixture occurs at a temperature not exceeding 232 C. 10. The process of claim 1 wherein the dilution of the heavy oil or bitumen comprise a ratio of from 1 to 10 parts by weight diluent per part by weight heavy oil or bitumen. 11. The process of claim 1 wherein the solvent deasphalting is at a ratio of from 1 to 10 parts by weight solvent per part by weight heavy oil or bitumen. 12. The process of claim 1 wherein the solvent comprises a hydrocarbon having 3
8 carbon atoms or a combination thereof. 13. The process of claim 1 wherein the solvent comprises a hydrocarbon having 4
7 carbon atoms or a combination thereof. 14. The process of claim 1 wherein the solvent comprises a hydrocarbon having 5 or 6 carbon atoms or a combination thereof. 15. The process of claim 1 wherein the heavy oil or bitumen is free of desalting upstream from the solvent deasphalting unit. 16. An integrated process for transporting and upgrading heavy oil or bitumen, comprising: diluting the heavy oil or bitumen with a diluent comprising a hydrocarbon having from 3 to 8 carbon atoms to form a mixture;

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17. Separating water and salts from the asphaltene fraction, the deasphalted oil fraction, and the solvent fraction at the solvent deasphalting unit, wherein sour water and chloride salts are recovered from the deasphalted oil fraction rendering the deasphalted oil fraction essentially free of water and chloride salts; and recycling at least a portion of the solvent fraction to the heavy oil or bitumen as the diluent to form the mixture. 18. The integrated process of claim 13, further comprising injecting seed water into the mixture prior to the solvent deasphalting unit to facilitate salt removal. 19. The integrated process of claim 13, further comprising diluting the heavy oil or bitumen with the diluent at a production site for the heavy oil or bitumen. In the same way, a simple alternative transport method for heavy oils was developed by Argillier et al. (2006). The present invention preferably applies to heavy crudes. It thus consists in modifying the structural organization of the heavy crude which behaves like a viscous colloidal suspension, to obtain a suspension of noncolloidal particles of lower viscosity. The particles concerned by this change are, within the context of a preferred embodiment of this invention, asphaltenes. The invention relates to a method of transporting a viscous petroleum effluent in pipes, wherein the following stages are carried out: 1. Separating the effluent into at least a solid phase consisting of particles coming from the colloidal elements that act on the viscosity of said effluent and into a fluidized liquid phase. 2. Keeping an amount of particles dispersed in said fluidized liquid phase so as to obtain a suspension. 3. Circulating said suspension in the pipe. The separation stage can be carried out by adding an amount of n-alkane such as butane, pentane, and heptane. The particles can be removed from the fluidized liquid phase. The colloidal elements acting on the viscosity can be asphaltenes. The particles can be dispersed through mechanical mixing. The temperature of said circulating suspension can be controlled in order to slow down the dissolution of the particles in the effluent. The temperature of the suspension can be kept below 40 C. Said particles can be encapsulated after separation. Said particles can be chemically modified prior to being dispersed in the fluidized effluent. In order to improve the economic sustainability, various forms of solvents have been proposed. He´naut et al. (2006) proposed the use of dimethyl ether (DME) under pressure as a solvent to adjust the viscosity and reduce the pressure drop in the pipeline. This invention thus relates to a method of diluting heavy crudes under pressure. It has been shown that wellchosen pressure and temperature conditions allow incorporation of DME to the crude and/or to a solvent used. The process allows not only to increase the polarity of the diluent, but also to greatly decrease the inherent viscosity thereof. Moreover, the recovery of DME in the refinery, as opposed to other solvents, is much easier. Other solvents that are being researched are alcohols, that is, pentanol is doubly effective in reducing the viscosity of heavy oil in comparison to kerosene, due to hydrogen bond interactions with the hydroxyl groups that feature some of the asphaltenes. Here, the higher the polarity or the hydrogen bonding parameter of the solvent, the greater the relative viscosity reduction of the diluted crude oil. Nevertheless, solvent owning high hydrogen bonding is generally more viscous than hydrocarbons. Only polar solvents with little hydrogen bonding give a significant reduction of the viscosity of the diluted crude oil (Gateau et al., 2004).

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Nowadays, naphtha or light crude oils are an interesting alternative to the use of natural gas condensates, due to its high API gravity and efficiency in the dilution of heavy oil. Nevertheless, the mixture may alter asphaltene stability provoking its flocculation and precipitation which may cause blockage of pipelines. Here, more studies are needed in order to understand asphaltene aggregation and flocculation as well as paraffin crystallization and deposition. Hence, we should also consider that the oil mixture may attain a lower selling price than the lighter fractions used as solvent since the lower quality of the heavy or extra-heavy oil and an economical evaluation are needed in order to assess the financial viability of the process. On the sustainability side, solvents used have the same sustainability constraint as other refining systems (Islam et al., 2010). They explained why current petroleum industry practices are inherently unsustainable and offers unique new solutions for “greening” the petroleum industry. This has been explained in a previous chapter of this book. 5.4.1.2 Formation of heavy and extra-heavy crude oil-in-water (O/W) emulsions An emulsion is a mixture of two or more liquids in which one is present as droplets, of microscopic or ultramicroscopic size, distributed throughout the other. Any emulsion has a continuous phase and a dispersed phase. Typically, the viscosity of an emulsion is less than the viscosity of the more viscous component of the emulsion. As such, it is advantageous to have emulsions formed within a heavy crude oil. Emulsions naturally occur in petroleum production and pipelining, most commonly those of W/O and some more complex structures of oil-in-water-in-oil (O/W/O) emulsions (Fig. 5.21). Emulsions at the production well are detrimental for oil production due to the following reasons: 1. 2. 3. 4.

viscosity implication; additional costs of oil water separation; increment corrosion issues; and difficult to break in desalting and dehydrating units before refining. FIGURE 5.21 Effect of pH on the viscosity and stability of Iranian oil sample emulsions (dashed lines present viscosity). Source: Redrawn From Ashrafizadeh, S. N., Kamran, M., 2010. Emulsification of heavy crude oil in water for pipeline transportation. J. Pet. Sci. Eng. 71 (3
4), 205
211.

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However, emulsions or dispersions of heavy or extra-heavy crude oil in water (O/W) or in brine may be an alternative to pipeline transportation of high-viscosity crudes because of viscosity reduction (Ashrafizadeh and Kamran, 2010). Ashrafizadeh and Kamran (2010) investigated stability and viscosity of W/O emulsions and their application for heavy oil pipeline transportation using two Iranian crude oil samples. An Iranian heavy crude oil sample named West Paydar and a blend of diesel and bitumen were used to produce heavy crude oil emulsions in water. The diverse factors affecting the properties and stability of emulsions were investigated. There was a restricted limit of 60 vol.% for crude oil content in the emulsions, beyond that limit the emulsions were inverted to W/O emulsions. This value is specific to the type of crude oil. In order to control emulsification, they used Triton X-100 surfactant. It is a nonionic surfactant, with major component being octylphenol ethoxylates. The investigations show that emulsification reduces the viscosity of the crude oil samples. However the viscosity of the emulsions increased by increasing the oil content of the emulsion, surfactant concentration, speed and time of mixing, salt concentration, and pH of the aqueous phase, while temperature of homogenization process substantially reduced the viscosity of the prepared emulsion. These cases of increasing viscosity are related to inversion of W/O emulsions to O/W emulsions. The increase in temperature decreases emulsion viscosity because of the drastic reduction in oil viscosity. The stability of crude O/W emulsions decreased by increasing the oil content while increasing the surfactant concentration, time and speed of mixing, pH of the aqueous phase and temperature enhanced the emulsion stability. The stability of crude oil emulsions was also increased by increasing the salt concentration. The main useful observation of their research is that heavy crude O/W emulsions can be highly stabilized simply by increasing the pH of the aqueous phase to basic values. Fig. 5.22 illustrates the effect of pH on the viscosity and stability of the emulsions. As it can be seen from this figure, increasing the pH of the solution has resulted in a negligible enhancement in the viscosity of the emulsions while that has increased the emulsions stability significantly. Increasing the pH of the continuous phase of the emulsions from 6 to 9 causes an increase in the absolute value of zeta potential of the droplets

FIGURE 5.22

Emulsions found in petroleum production and transport.

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which results in the formation of emulsions with higher stabilities observed that O/W emulsions became more stable at higher pH values and attributed this phenomenon to the higher affinity of surfactant molecules toward aggregation at higher pH values. An O/W emulsion is a mixture of two immiscible liquids where oil phase is dispersed into the water continuous phase (Fig. 5.2). In some locations, hydrocarbon diluents or lighter crudes may be not available or limited while fresh water, sea water or even formation water may be available for emulsification. Very often O/W emulsions are deliberately produced to reduce the viscosity of highly viscous crude oils so that they can be transported easily through the pipeline. This is accomplished by using surfactants. The O/W emulsion reduces the viscosity of heavy crude oils and bitumens and may provide an alternative to the use of diluents or heat to reduce viscosity in pipelines (Langevin et al., 2004). Langevin et al. (2004) reviewed advances have been made in the field of emulsions. Emulsion behavior is largely controlled by the properties of the adsorbed layers that stabilize the oil-water surfaces. The knowledge of surface tension alone is not sufficient to understand emulsion properties, and surface rheology plays an important role in a variety of dynamic processes. The complexity of petroleum emulsions comes from the oil composition in terms of surface-active molecules contained in the crude, such as low molecular weight fatty acids, naphthenic acids and asphaltenes. These molecules can interact and reorganize at oil
water interfaces. The pronounced nonlinear behavior of surface rheology for asphaltene layers might explain differences in behavior between surfactant and asphaltene emulsions. These effects are very important in the case of heavy oils because this type of crude contains a large amount of asphaltene and surface-active compounds. Overall, heavier crudes have all timedependent parameters that take longer to stabilize, thus making the process highly nonlinear. The major application of an O/W emulsion is the orimulsion process developed by PDVSA (Petro´leos de Venezuela) in the eighties and commercialized by its filial Bitumenes Orinoco S.A. (Salager et al., 2001). Orimulsion is a bitumen-in-water emulsion. Raw bitumen has an extremely high viscosity and specific gravity between 8 and 10 API gravity, at ambient temperatures and is unsuitable for direct use in conventional power stations. Orimulsion is made by mixing the bitumen with about 30% fresh water and a small amount of surfactant. The result behaves similarly to fuel oil. Initially phenol-based surfactants were used. They were later replaced with alcohol-based surfactants. This helped with the transport qualities as well as reducing health hazards associated with the phenol group of surfactants. One interesting feature of the process is, Orimulsion can be used directly as feedstock for heat/power generation in thermoelectrical plants. In this niche market, the initial pricing structure competed well with coal price. This product was successful till the late 1990s, when oil upgrading became a reality and starts to compete for the bitumen with the emulsion. Since then, PDVSA could make more profits from Venezuelan exportations of extra-heavy oil and bitumen by selling blends or syncrude instead of Orimulsion as well as producing fuels for internal consumption. Hence, PDVSA announced the closure of its filial BITOR on 2003 but also its intention to fulfill the long-term contracts with Canada, Denmark, Italy, Japan, and China (Blaˇzek, 2007). Orimulsion is a product oriented to electricity production and would be interesting to developing countries with limited coal and gas reserves and refining capacity but the last word to reactivate emulsion production remains in PDVSA. Here, the emulsion of vacuum residue in water for heat/power generation could be an economical alternative instead of using heavy or extra-heavy oil (Fig. 5.23).

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FIGURE 5.23 Extra-heavy crude oil in water (O/W) diluted emulsion for visual purpose. A drop of the O/W emulsion (30% water) was diluted in 5 mL water (unpublished data) and the photo was taken without enlargement.

An effective way to reduce the viscosity of heavy oil is the formation of O/W emulsions with the help of surfactant agents. In this way, crude oil is transported in the form of fine crude oil droplets in a continuous phase consisting mainly of water or other types of aqueous solution. The O/W emulsions do not form spontaneously and need an energy input to form, which is traditionally achieved through shaking, stirring or some other kind of intensive dynamic and/or static mixing processes. In order to assure emulsion stability during pipelining, it is necessary to add surfactants (low molecular weight) to reduce oil interfacial tension and in some cases additional substances as stabilizing agents (high molecular weight) to avoid phase separation. In this process, nonionic surfactants are more versatile considering their ability to withstand high salinity. In general nonionic emulsifiers are desirable in preparing emulsions because they are not affected by the salinity of the water used, they are relatively cheap, and they do not produce any undesirable organic residue that can affect the oil properties. A loss of surfactant stability would collapse the emulsions and create two phase flow, thus increasing the pressure needed to continue the flow. Rivas et al. (1998) introduced such surfactants. A stable hydrocarbon-inwater emulsion includes a hydrocarbon phase containing natural surfactant; a water phase having an electrolyte content greater than about 10 ppm (wt) and less than or equal to about 100 ppm (wt) with respect to the water phase; and a surfactant additive including an amine and an ethoxylated alcohol in amounts effective to activate the natural surfactant and stabilize the emulsion.

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Typically, the use of surfactants can significantly increment the cost of an O/W emulsion but the activation of natural surfactants occurring in heavy and extra heavy crude oils is a reliable option. The ionization of acid groups present in fatty and naphtenic acids as well as asphaltenes with a strong alkali can make these surfactants more hydrophilic which allow the reduction of the interfacial tension. Emulsion behavior is largely controlled by the properties of the adsorbed layers that stabilize the oil-water surfaces. In addition to surface tension, surface rheology also plays an important role in a variety of dynamic processes. The complexity of petroleum emulsions comes from the oil composition in terms of surfaceactive molecules contained in the crude, such as low molecular weight fatty acids, naphthenic acids, and asphaltenes. These molecules can interact and reorganize at oil
water interfaces. The pronounced nonlinear behavior of surface rheology for asphaltene layers might explain differences in behavior between surfactant and asphaltene emulsions. These effects are very important in the case of heavy oils because this type of crude contains a large amount of asphaltene and surface-active compounds. This article reviews different petroleum emulsion properties and the transport of high viscosity hydrocarbon as a crude O/W emulsion. Langevin et al. (2004) reviewed different petroleum emulsion properties and the transport of high viscosity hydrocarbon as a crude O/W emulsion. Pipelining of crude oil must transport as much oil as possible and as little water as possible for economical reasons. However, a threshold value of water content is required. The required viscosity for transport, typically around 400 cP at ambient temperature, may be attained only with 25%
30% w/w water content. Above 70% of oil in emulsion, the viscosity may become too high or to inverse to W/O emulsion. The surfactants should allow at the same time a simple but efficient rupture of the O/W emulsion before crude oil refining and the separated water should be treated in order to comply with environmental and industrial regulations for water discharge or recycling. Then, it is necessary to develop surfactants that may form a metastable and easy-to-break emulsion that should require the minimum quantity of surfactant and other additives. Note that emulsions are artificial and, depending both on the metastability of the freshly formed interfaces and the fragmentation procedure that is employed, various structures may be generated. However, their lifetime may vary considerably: some systems are impossible to prepare whatever the employed procedure, some others disappear within a few seconds or a few hours and some others may stand for many years. Destruction of emulsions may proceed through two distinct mechanisms (Leal-Calderon and Poulin, 1999): 1. Ostwald ripening. It takes place when the dispersed phase is soluble enough within the continuous phase and consists of a gradual coarsening of the emulsions. 2. Coarsening. This mechanism, known as coalescence, consists in the rupture of the thin film that forms between adjacent droplets leading two droplets to transform into only one. Deminiere et al. (1999) conducted visualization experiments to observe monodisperse emulsions in time-lapsed coalescence of emulsions. Coalescence was produced by increasing the temperature. They observed that the droplet growth is surprisingly homogenous and monodisperse. They prepared monodisperse droplets stabilized by a nonionic surfactant, which do not exhibit any noticeable change within months at room temperature. Fig. 5.24 (A
D) shows the long time (upto several hours) evolution of an emulsion when heated at 80 C. The droplet growth is surprisingly homogeneous and monodisperse as can be seen on these microscopic pictures.

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FIGURE 5.24 Miscroscopic observation of the droplet size evolution of a silicone-in-water emulsion stabilized by Lauropal 205 (A, 1 h; B, 2 h; C, 3 h; and D, 4 h), the temperature being 80 C. (Palou et al., 2011).

The Bancroft rule in colloidal chemistry states that “The phase in which an emulsifier is more soluble constitutes the continuous phase.” As such, the type of the resulting emulsion and in the case of O/W emulsions, the surfactant should be soluble in the continuous phase. Consequently, pipeline-transportable heavy O/W emulsions cannot be formed by directly combining the surfactant agents with the oil and subsequently mixing. The surfactant agents must be solubilized first in an aqueous solution, so premixing with water, brine, or the like, making possible the diffusion of the surfactant to the oil
water interface. The use of a dynamic mixer, such as a rotor-stator mixer, may cause the formation of oil droplets having a diameter of less than 10 μm, which is detrimental to pipelining as such small oil droplets increase the viscosity of the O/W emulsion, and can cause emulsion inversion to an oil continuous emulsion, with a significant increase in viscosity. In general, O/W emulsions cannot be formed by combining emulsifying agent(s) directly with produced hydrocarbon crude, and subsequently agitating with a dynamic mixer the mixture of produced hydrocarbon crude and emulsifying agents. The emulsifying agent is not soluble in oil and is only soluble in an aqueous solution. By contacting directly, the produced hydrocarbon crude with the emulsifying agent without premixing the emulsifying agent with water or brine, diffusion of the emulsifying interface is slow. For heavier hydrocarbons, such as bitumen or tar sand, this is almost impossible to form emulsions. Also, through the use of a dynamic mixer, such as the rotor
stator mixer, not every produced hydrocarbon crude can be emulsified into a water continuous emulsion,

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even with premixing the emulsifying agents with water prior to combining with produced hydrocarbon crude. A high shear field cannot be obtained with a dynamic mixer unless the mixture of produced hydrocarbon crude and emulsifying agents (including any water solvent) makes numerous passes through the dynamic mixer. Transportation of emulsions is shear-sensitive, and a dynamic mixer tends to cause either an overshear-damaged product or less than a perfectly mixed product, depending on the mixing severity employed with the dynamic mixer. Large storage tanks and/or mixing tanks are generally required when utilizing dynamic mixers before the mixture can be transported in the pipeline. If a dynamic mixer is separate from the storage tank, mixtures to be emulsified have to be recirculated from the storage tank, through the mixer, and back into the storage tank. The degree of mixing achieved by dynamic mixers depends on the following factors: 1. 2. 3. 4. 5. 6.

Mixing speed; Impeller design; Impeller position; Length of mixing time; Tank volume; Tank geometry.

Dynamic mixers are prone to producing a large quantity of oil droplets having a diameter of less than 10 micron, which is detrimental to the transport of O/W emulsions as such small oil droplet increase the viscosity of the O/W emulsions, and can cause the O/W emulsions to invert from a water continuous emulsion into an oil continuous emulsion, with an attendant increase in viscosity. Dynamic mixers are also susceptible to high maintenance expense because of their use of high-speed rotating devices. In order to remedy the above difficulties, Gregoli et al. (1994) invented several patents. These inventions involve processing for the preparation of stable water-continuous crude oil, or other hydrocarbon, transport emulsions, and which can generally form an emulsion having a water-continuous phase of any produced hydrocarbon crude, especially Athabasca bitumen (e.g., Syncrude bitumen). Their primary invention is an O/W emulsification technology capable of reducing crude oil viscosity using an eccentric cylinder mixer that allows a low energy laminar flow. The mixer’s geometry allows the existence of chaotic flows that are able to mix well highly viscous fluids. The presence of chaotic flow increases the surface area exponentially, thus making it easier to form stable emulsions. Zaki (1997) studied the stability and viscosity of a surfactant-stabilized O/W emulsion for pipeline transportation using an Egyptian Geisum crude oil. His study revealed that viscosity and stability of the emulsion increases with the concentration of an anionic surfactant that reduces the O/W interfacial tension and size of dispersed droplets because of a higher coverage of surfactant molecules at the oil
water interphase. The viscosity of the studied Geisum-crude- O/W emulsion was decreased by decreasing the oil content and the speed of mixing and increasing the temperature. The pour-point values for O/W emulsions having different oil contents were always less than those of the Geisum crude oil. Demulsification of the stable crude- O/W emulsion was achieved by treatment with 60 ppm alkyl phenolformaldehyde oxyalkylated chemical demulsifier at 50 C. As shown in Fig. 5.25, which is a plot of the apparent dynamic viscosity as a function of the mixing temperature measured at 20 C for the freshly prepared emulsions, the plot

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FIGURE 5.25

Influence of mixing temperature on the emulsion dynamic viscosity, measured at 20 C. Source: From Zaki, N.N., 1997. Surfactant stabilized crude oil-in-water emulsions for pipeline transportation of viscous crude oils. Colloids Surf. A: Physicochem. Eng. Asp. 125 (Issue 1), 19
25. Available from: ,https://doi.org/ 10.1016/S0927-7757(96)03768-5..

clearly demonstrates the fact that increasing the mixing temperature results in a subsequent decrease in the apparent dynamic viscosity of the emulsion Similar results were found in a nonionic surfactant-stabilized O/W emulsion (Yaghi and Al-Bemani, 2002). They observed that heating had a dramatic effect on the heavy crude viscosity, but it failed to achieve a practical level; consequently, blending the heavy crude with either light crude or kerosene was attempted and further reduction was achieved. This, however, needed substantial amounts of expensive diluents. Alternatively, emulsion formation was carried out, and it was established that a practical level of reduction is achievable at 70%
75% oil content, in the high shear rate range, and at 30 C
50 C. A nonionic emulsifier, called Emulgen 120 (polyoxyethylene (13.3) lauryl ether), was used to stabilize the emulsions. The use of anionic and nonionic surfactants produce a synergistic effect. Ahmed et al. (1999) reported that the use of formation water instead of fresh water resulted in a lower interfacial tension between crude oil and formation water and a more viscous O/W emulsion because of the formation of smaller crude oil droplets. Hence, the lower interfacial tension between phases allowed a larger volume fraction of the dispersed phase with an increased droplet
droplet interaction that leads to an increase in emulsion viscosity and stability. 3. The presence of the anionic and the nonionic surfactants together has a synergistic effect, the nonionic surfactant has a positive contribution in forming emulsions with low viscosity. Meanwhile, the anionic surfactant contributes in stabilizing the emulsion at lower concentrations. For the fresh water containing emulsion, the lowest viscosity (84 cP) was achieved when using 156 ppm of the anionic surfactant mixed with 78 ppm of the nonionic surfactant. In case of emulsions containing formation water, the lowest viscosity (59 cP) was achieved when using 625 ppm of anionic mixed with 1250 ppm of nonionic. However, lower concentrations of surfactants (156 ppm of anionic mixed with 625 ppm of nonionic) could be used resulting in the formation of emulsions having acceptable viscosity (145 cP). These values are amenable to pipeline transport. It is known that the stability of the emulsions depends on many parameters as follows (Hayes et al., 1988): 1. The composition of oil in terms of surface-active molecules; 2. Salinity and pH of water, water volume; 3. Size of the droplets and their polydispersity;

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Temperature; Type of surfactants; Surfactant concentration; Energy in mixing.

A host of patents was issued to Hayes et al. (1988), and outlining methods and compositions is to facilitate the transportation and combustion of highly viscous hydrocarbons by forming reduced viscosity hydrocarbon-in water emulsions, and in particular, bioemulsifier-stabilized hydrocarbon-in-water emulsions. In order to reduce these uncertainties, the use of “surfactant packages” containing a water-soluble chemical surfactant, or a combination of water-soluble chemical and/or biological cosurfactants, together with a bioemulsifier, surfactants of biological origins, that binds to the hydrocarbon/water interfaces. Hayes et al. (1988) state that it is possible to transport by pipeline viscous hydrocarbons through the formation of low-viscosity biosurfactant-stabilized O/W emulsions, or the so-called hydrocarbosols. Here, hydrocarbon droplets dispersed in the continuous aqueous phase are substantially stabilized from coalescence by the presence of biosurfactants and in particular, microbial biosurfactants. The microorganisms predominantly reside at the hydrocarbon/water interface, covering the surface of the hydrocarbon droplets, protecting them from coalescence, and maintaining the reduced viscosity over time. The hydrocarbosols reported present viscosities reduced by at least a factor of 10 and the preferred water-soluble nonionic chemical surfactants for viscous crude oils are the commercially available ethoxylated alkyl phenols and ethoxylated alcohols; while the preferred water-soluble anionic chemical surfactants are ethoxylated alcohol sulfates. Among the preferred biosurfactants are heteropolysaccharide biopolymers produced by bacteria of the genus Acinetobacter and the genus Arthrobacter, and in particular, those produced by strains of Acinetobacter calcoaceticus. Still some heavy oils were not successfully emulsified with the surfactant packages studied (Figs. 5.26 and 5.27). Bioemulsifiers, specifically extracellular microbial polysaccharides (emulsans) produced by different strains of the Acinetobacter bacteria have been extensively researched by several researchers (e.g., Gutnick et al., 1983; Gutnick and Bach, 2003). These are very efficient O/W emulsifiers possessing a high degree of specificity in both fresh water and sea water for emulsifying hydrocarbon substrates which contain both aliphatic and aromatic or cyclic components. Bioemulsifiers generally work by orienting themselves at the oil
water interface, avoiding the coalescence of the oil droplets and stabilizing the resulting emulsion. FIGURE 5.26 The process schematic for the Hayes et al. (1988) invention.

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FIGURE 5.27 Improvements in reducing oil viscosity with hydrocarbasols (Hayes et al., 1988).

Growth of Acinetobacter sp. ATCC 31012 on various substrates and undervarying conditions has been used to produce two classes of extracellular microbial protein-associated lipopolysaccharides (emulsans) which, on a weight-for-weight basis, are probably the most efficient emulsifiers discovered and which possess certain characteristics that permit these unique extracellular microbial lipopolysaccharides to be widely used in cleaning oilcontaminated vessels, oil spill management, and enhanced oil recovery by chemical flooding. These classes have been named α-emulsans and β-emulsans, both of which have substantially the same polymer backbone but differ from each other in certain important structural aspects. Emulsans and apoemulsans, both of which biopolymers are strongly anionic, exhibit a high degree of specificity in the emulsification of hydrocarbon substrates which contain both aliphatic and cyclic components. In addition, these extracellular microbial polysaccharides as well as their O-deacylated and N-deacylated derivatives are adsorbed on and capable of flocculating aluminosilicate ion-exchangers, such as kaolin and bentonite. Since it is not easy to produce stable heavy O/W emulsions, it is necessary to control and improve the process at every stage. In some cases, especially with extra-heavy oils, the formation of an O/W emulsion will not occur. Still, there have been several scientific advances over the past 40 years, allowing for a better understanding of these complex systems. However, there are still many unresolved questions related to the peculiar behavior of these emulsions. Its complexity comes from the molecular composition of oil, which covers a wide range of chemical structures, molecular weights, the HLB (hydrophilic
lipophilic balance) values of the surfactants, the multiple interactions of oil
water surfactant, and the possible molecular rearrangements at the oil
water interface.

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5.4.1.3 Heavy oil emulsions for transport in cold environments Heavy oil in cold environments can be efficiently transported through a large diameter insulated pipelines at temperatures below 273.15K in the form of 40%
70% w/w oil-inbrine emulsions containing salts dissolved in the water in amounts sufficient to prevent freezing. These operating conditions permit the insulated pipeline to be buried in the ground without causing thawing of the permafrost, which in turn can cause damage to both the environment and the pipeline. Marsden Jr, Sullivan S., and Stephen C. Rose. “Pipelining crude oils and tars containing dissolved natural gas at subfreezing temperatures in order to avoid environmental damage.” U.S. Patent No. 3,670,752. 20 Jun. 1972. Marsden and Rose (1972) patented one of the first technologies that suggest that natural gas can be transported dissolved in the cold heavy oil emulsion with considerable economic advantage. The patented technology involved rude oils and tars, such as those obtained from the Prudhoe Bay Oil Field and the Athabasca Tar Sands, can be efficiently transported through a large diameter insulated pipeline at temperatures below 32 F., for example, between about 15
30 F., in the form of 40% to 70% oil-in-brine emulsions containing salts dissolved in the water in amounts sufficient to prevent freezing at said temperatures. These operating conditions permit the insulated pipeline to be buried in the ground without causing thawing of the permafrost which will lead to significant damage to both the environment and the pipeline. Subsurface construction of a pipeline of this sort has considerable economic advantage over the above-ground, supported construction required for a heated oil pipeline to avoid environmental damage. Dissolution of gas in the crude oil at these low temperatures, thus allowing transport of the gas in the same pipeline, also adds considerable economic advantage. Even at these low temperatures, the emulsion has an effective viscosity comparable to that of the oil alone at much higher temperatures so that energy consumption for pumping is at an acceptable level. On arriving at the discharge terminal, the cold emulsion can then be broken down into its constituents by heating the same either with or without the addition of demulsifying chemicals. It is well established that the solubility of natural gas in crude oil decreases as the temperature increases and conversely that the solubility of gas in crude oil increases as the temperature is lowered. Natural gas in remote areas used to be just disposed of through flaring. With the advent of LNG markets, it is now possible to establish long-term supply contracts that would make financially feasible such technology option. LNG is natural gas that has been cooled to a liquid state (liquefied), at about 2260 F, for shipping and storage. The volume of natural gas in its liquid state is about 600 times smaller than its volume in its gaseous state in a natural gas pipeline. This liquefaction process, developed in the 19th century, makes it possible to transport natural gas to places natural gas pipelines do not reach and to use natural gas as a transportation fuel. Where natural gas pipelines are not feasible or do not exist, liquefying natural gas is a way to move natural gas from producing regions to markets, such as to and from the United States and other countries. Asian countries combined account for the largest share of global LNG imports. LNG export facilities receive natural gas by pipeline and liquefy the gas for transport on special ocean-going LNG ships or tankers. Most LNG is transported by tankers called LNG carriers in large, onboard, supercooled (cryogenic) tanks. LNG is also transported in smaller ISO-compliant containers that can be placed on ships and on trucks. At import terminals, LNG is offloaded from ships and is stored in cryogenic storage tanks before it is returned to its gaseous state or regasified.

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After regasification, the natural gas is transported by natural gas pipelines to natural gas-fired power plants, industrial facilities, and residential and commercial customers. The transportation feasibility of dissolved natural gas might depend on the concentration of oil in the oil-in-brine emulsion, the pressure in the pipeline, the emulsion temperature at this pressure, and the investment and operation costs of high pressure pipelines. If natural gas contains significant amounts of gases as hydrogen sulfide or carbon dioxide, these gases should be removed. Emulsions are difficult to handle in cold environments because of phase destabilization, freezing or an increase in viscosity to a level too high for pipeline transport. In a 1992 patent, Gregoli and Olah (1992) proposed the use of common surfactants mix to form the emulsion and supplemented by use of the xanthan biopolymer to enhance the stability of the emulsion. In this process, stable O/W emulsions for pipeline transmission are formed at a temperature of from about 100 F to about 200 F, preferably using at least one ethoxylated alkylphenol compound and a freezing point depressant for water to enable pipeline transmission at temperatures below the freezing point of water. The aqueous solution is suggested to be brine with a high salt content and the use of freezing point depressants like ethylene glycol in sufficient concentration to maintain the oil-in-brine emulsion in pipeline condition at 253.15K or less, but insufficient to cause a permanent loss of the emulsion. 5.4.1.4 Heating heavy and extra-heavy crude oil and heated pipelines This is the second most used method for transporting heavy oil with pipelines. The principle is to conserve the elevated temperature (, 373.15K) at which the oil is produced at the well-head through insulation of the pipelines. Nevertheless, external heating of the heavy oil is always needed because of heat losses that always occur, as a result of low flow or unused pipeline capacity. The heating method works only when oil is reheated in the pumping stations through direct-fired heaters. Insulation options include burying the pipeline to conserve heat. Also, traditional oil pipelines operate with a low vapor pressure restriction, close to ambient pressure, in order to maximize their capacity. Ghannam and Esmail (2006) studied the thermal flow enhancement of a medium Canadian crude oil (density (ρ) 5 0.929, μ 5 1375 cP at 393.15K). Their study investigated the different alternatives to enhance the flowability of crude oil with medium viscosity. These alternatives include the addition of water into crude oil to form W/O emulsion, the addition of light petroleum product, the addition of flow enhancing agents, and a preheating technique. Temperature range of 10 C
50 C, water concentration range of 0%
50% by volume, flow enhancer concentration range of 0
5000 ppm, and kerosene concentration range of 0%
50% by volume were investigated in the flowability enhancement study of crude oil with medium viscosity. The addition of kerosene to crude oil was found to improve the flowability much better than any other investigated technique. The viscosity at 10/s shear rate was reduced from roughly 700 to 300 cP by heating the medium crude oil from 283 to 303K. The effect of temperature on viscosity of the assayed crude oil was very important since it is not a very viscous crude oil as others as the Canadian Athabasca, the Venezuelan oil sands or the Mexican Ku-Maloob-Zaap or Ayatsil-Tekel crude oils. However, the authors concluded that the preheating of this kind of medium crude oil is impractical because subsequent heating is required to maintain flow. Fig. 5.28 shows the viscosity behavior for W/O emulsions as reported by Ghannam and Esmail (2006).

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Fig. 5.29 shows the relative viscosity for W/O emulsions versus shear rate for different water concentrations. Relative viscosity is defined by η 5 emulsion viscosity/continuous phase viscosity. Relative viscosity increases slightly with water concentration until a water concentration of 25%. However, it decreases significantly by more addition of water and shear rate.

FIGURE 5.28 Viscosity behavior for W/O emulsions.

FIGURE 5.29 Relative viscosity of W/O emulsions.

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Fig. 5.29 shows the viscosity behavior of crude oil in the presence of different concentrations of kerosene at room temperature. Kerosene has a strong ability to dramatically lower the crude oil viscosity. Table 5.8 reports the viscosity measurements of crude oil at different concentrations of kerosene and at three values of shear rate of 0.3, 10, and 750/s, respectively. Table 5.8 also reports the viscosity reduction percent for each kerosene concentration at 0.3, 10, and 750/s shear rate. It can be concluded that a reasonable amount of kerosene addition will cause a huge viscosity reduction. This viscosity reduction could reach up to around 50% for 10% kerosene addition, around 80% for 25% kerosene addition, and around 90% for 50% kerosene at shear rate values of 0.3, 10, and 750/s, respectively. Therefore, the addition of kerosene to crude oil enhances the oil flowability much better than most other approaches such as W/O emulsion and flow property techniques (Fig. 5.30). TABLE 5.8 Drag reduction of heavy crude using some reported drag reducing agents (Milligan et al., 2008). Drag reduction in heavy crude using LP 300 versus polymer A and polymer B Product

Concentration (ppm)

Drag reduction (%)

LP 300

187

0

Polymer A

50

28.5

100

39.5

50

28.8

100

36.7

Polymer B

FIGURE 5.30

Effect of kerosene on crude oil viscosity.

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Perry (2007) disclosed a novel technique that eliminates the need for direct heating along the pumping stations where crude oil temperature can be controlled by varying the design choices of line diameter, station spacing, operating pressure range and the viscosity specification of the transported oil at ambient temperature. The main mechanism involves shear heating provided by external friction or internal friction acts to heat the heavy oil to increase or maintain the temperature of the heavy oil as it flows through the pipeline. Here, the temperature increases through friction in the pump as pressure augments and from the heat generated by internal shear friction of turbulent flow within the heavy oil as it flows at high velocities throughout the pipeline. Some pipeline designs can reach temperature increments of about half degree Celsius for every 15
30 km of distance, with an equilibrium temperature at 338.7K. The pipeline may be designed to enhance shear heating. The method applies when designing a new pipeline that is at least 250 km long, preferably 500 km with a high-pressure specification and of course, high investment cost. The fluid to be transported should be heavy oil diluted with a liquid hydrocarbon having five or fewer carbon atoms that has a high (.atmospheric pressure) vapor pressure. The resulting expensive pipeline system may have a pressure drop of 1250 psia (86 bar) between stations, sufficient to generate a shear heating effect. Rather than wait for this effect to slowly heat the oil as it travels down the pipeline, a heater is proposed at the front end of the pipeline, so that the diluted heavy oil equilibrium temperature is maintained throughout the pipeline system. The higher the oil viscosity, the greater the internal shear friction and more heat is generated, but since the system has to be designed considering shutdown conditions, diluted heavy oil is recommended. This shear heating effect is not seen with normal light and medium gravity oil, as the viscosity within the transport system is too low.

5.4.2 Electrically heated subsea pipelines Subsea pipelines are crucial to the offshore production infrastructure but they often prove to be a weak link in certain cases where the hydrocarbon reservoir produces heavy or extra-heavy oils, which tend to become thick and viscous at the temperature of the subsea environment. The usual solution for small distances (less than a mile) is insulating the pipelines and moving the produced well fluids as quickly as possible to minimize temperature losses. However, passive insulation becomes ineffective when longer lengths of pipeline are needed to transport the oil and higher pressures may require expensive subsea booster pumps. Supplying power for booster pumps or auxiliary heating along the pipelines is a difficult proposition for remote subsea wells and pipelines. An alternative to consider is the electrically heated subsea pipeline for the transport of heavy oils as suggested by Langner and Bass (2001). This method involves heating a subsea pipeline in which a pipe-in-pipe subsea pipeline is established having a flowline for transporting well fluids in the form of an electrically conductive inner pipe concentrically surrounded by an electrically conductive protective outer pipe and the inner pipe is electrically insulated from the outer pipe along the length of the subsea pipeline. The pipe-in-pipe subsea pipeline is electrically heated continuously along its length to maintain the temperature of crude oil at a level facilitating pipeline transportation, this heating comprising passing alternating electrical current along the exterior surface of the inner pipe and along the interior surface of the outer pipe. In this manner the crude oil can be maintained at a temperature at which viscosity does not prevent efficient and economical pipeline transport (Fig. 5.31).

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FIGURE 5.31

Axial cross sectional view of a thermal insulator of the embodiment of the invention of Langner and Bass (2001).

Two configurations for electrical heating are available: a single heated electrically insulated pipeline (SHIP) where electrical current flows along the pipe and a pipe-in-pipe subsea pipeline where the oil flows through the inner electrically insulated pipe, which is surrounded concentrically by an electrically conductive outer pipe. In the latter, heating is caused by a combination of electrical resistance and magnetic eddy effects associated with transmission of an alternating current through the pipeline. Previously, with the invention of Bass and Langner (2000) noted that AC power has several benefits over DC power, and is preferred for this application. A power input is provided on the surface facilities, which is electrically connected across the inner and outer pipes at the first end of the pipeline and an electrical pathway electrically connects the inner and outer pipes at the second end of the pipeline. The power and voltage requirements for direct electrical heating of the pipeline and power transmission are within conventional AC power engineering limits and are already available on platforms in standard 60-Hertz power plant configurations. Although it may be desirable to alter the frequency in certain applications, the basic power commitments for pipe lengths up to 65 km are achievable without special purpose generators. Second, DC power raises significant concerns about corrosion control for the underwater pipelines, which is not an issue with AC power. The concentric pipe-in-pipe configuration is costly to deploy and operate because of the complexity of the pipeline design and the fact that it is necessary to have the whole length of the pipeline heated.

5.4.3 Pour point depressants PPDs are used to allow the use of petroleum based mineral oils at lower temperatures. The lowest temperature at which a fuel or oil will pour is called a pour point. Wax crystals, which form at lower temperatures, may interfere with lubrication of mechanical equipment. Wax inhibitors include thermodynamic wax inhibitors, dispersants, and surfactants, as well as PPDs (Bai and Bai, 2012).

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Thermodynamic wax inhibitors are solvents or crude oil distillates that decrease WAT but are deemed uneconomic due to a high volume required. Dispersants and surfactants act on the wax crystal surface, reducing particle
particle or particle
wall adhesion (Bai and Bai, 2012). PPDs lower the pour point, which is defined as the temperature, at which the waxy oil loses its ability to flow freely. PPDs are considered to predominantly act as crystal modifiers. Crystal modifying substances alter wax crystal morphology via cocrystallization. During continued crystal growth, the incorporated PPD molecule can impose spatial hindrances to wax molecules that further precipitate on the crystal, leading to crystal distortion. This is often realized by polar moieties in the otherwise hydrocarbon-like polymer (Wei, 2015). The hydrodynamic radius of wax crystals can thereby be reduced, as well as the propensity to overlap and form volume spanning networks. Wax crystal modifiers are materials that have similar chemical structure to the wax that is precipitating. The typical wax crystal modifiers are polymeric compounds constituted by one or more hydrocarbon chains (wax like) and polar portion. This type of compounds can coprecipitate or cocrystallize with wax by occupying the position of wax molecules on the crystal lattice through the hydrocarbon chains; meanwhile, it also places a steric hindrance on the crystal which can interfere the growth and aggregation of wax crystals and frequently reduce the pour point of crude oils. This process is clearly illustrated in Fig. 5.32 (Al-Yaari, 2011). Ethylene-vinyl acetate (EVA) copolymers are the most extensively used wax crystal modifiers. This kind of copolymers has a linear chain composed of polyethylene portion with varying length depending on the quantity of copolymerized monomer (vinyl acetate). The chemical

FIGURE 5.32 Schematic representation of wax crystal modifier cocrystallization with wax crystals. Source: AlYaari, M., 2011. Paraffin wax deposition: mitigation & removal techniques. In: SPE-55412 Presented at SPE Saudi Arabia section Young Professionals Technical Symposium. Dhahran, Saudi Arabia, pp 14
16.

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FIGURE 5.33

Chemical structure of ethylene-vinyl acetate copolymer.

structure of EVA is shown in Fig. 5.2. It has been recognized that the EVA copolymers exhibit varying degree of capacity in controlling the size of formed wax crystals (Vieira et al., 2012). When EVA is successfully used, the produced crystals are considerably smaller and more numerous than those crystallized from untreated systems (Petinelli, 1979) (Fig. 5.33). The influence of EVA copolymers containing different content of vinyl acetate on the viscosity and pour point of a Brazilian crude oil was investigated by Machado et al. (2001). A systematic study of the viscosity, pour point, and wax appearance temperature of a waxy North Sea crude oil was done with 12 different commercial PPDs (Pedersen and Rønningsen, 2003). Experimental data are presented for the viscosity, pour point, and wax appearance temperature of a stabilized, waxy North Sea crude oil treated by 12 different commercial wax crystal modifiers, all of which may potentially act both as wax deposition inhibitors and PPDs. The viscosity data cover the temperature range from 40 C to 5 C. In general, the studied chemicals only marginally influence the wax appearance temperatures whereas the majority has a pronounced effect on pour points and apparent viscosity. The viscosity data suggest that the inhibitors, probably by some kind of steric hindrance, “inactivate” wax components within a certain range of molecular weight by preventing them from building of network structures. It is shown that this effect can be modeled by assuming a lowering of the melting temperatures of the affected range of wax molecules. These are substances capable of building into wax crystals and alter the growth and surface characteristics of the crystals, reducing the tendency to form large crystals as well as their adherence to metal surfaces such as pipe walls. Pedersen and Rønningsen (2003) observed a large viscosity reduction (from 1000 to 10 cP) of the crude oil for temperatures between 283K and 293K for all flow improver additives. The effect on crude oil viscosity was successfully modeled by assigning a lower melting temperature to wax molecules in the range C21
C45 in the presence of a flow improver additive (Fig. 5.34). More recently, the PPD performance on the rheological properties of light and heavy Mexican crude oils was tested with various copolymers based on different combinations of vinyl acetate, styrene, and n-butylacrylate between 298K and 323K. The pour point in light or heavy crude oils diminished about 20 C and 10 C with a styrene or vinyl acetate copolymers, respectively. The viscosity of the light crude oil was reduced only upon 313K while for the heavy crude oil, the effect of the PPD on viscosity reduction was noticeable from 298K.

5.4.4 Reducing friction 5.4.4.1 Drag reducing additives When fluids are transported by pipeline, the force that must be overcome to drive the fluid through the pipeline is defined as the drag force. This drag is the result of stresses at

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FIGURE 5.34 Precipitated weight of paraffin from the oil with (dashed line) and without (solid line) inhibitor. Source: Adapted from Pedersen, K.S., Rønningsen, H.P., 2003. Influence of wax inhibitors on wax appearance temperature, pour point, and viscosity of waxy crude oils. Energy Fuels 17 (2), 321
328.

the wall (due to fluid shearing) causing a drop in fluid pressure. Due to this pressure drop, the fluid must be transported with sufficient pressure to achieve the desired throughput. When higher flow rates are needed, fluid deformation is higher and shear stresses increase, so more pressure must be applied to maintain the flow at the same average velocity. However, specifications of pipeline design may limit the amount of pressure that can be employed or rise substantially the investment costs. The problems associated with pressure drop are more acute when fluids are transported over long distances, so drag reducing additives may be incorporated in the flowing fluid. The role of these additives is to suppress the growth of turbulent eddies by the absorption of the energy released by the breakdown of the lamellar layers, which results in higher flow rate at a constant pumping pressure. Hence, turbulent flow and therefore drag reduction are difficult with heavy and extra heavy crude oils because of the high viscosity and that flow is generally laminar. Nevertheless, we must also consider that heavy and extra heavy crude oils may be diluted or heated to assure, at least, transitional flow where the use of drag reducers may be important to delay the onset of turbulent eddies (Johnston et al., 2008). Drag reducing agents (DRAs) can be divided in three main groups: 1. surfactants; 2. fibers; 3. polymers.

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Surfactants can reduce the surface tension of a liquid while fibers and polymers orient themselves in the main direction of the flow, limiting eddies appearance which results in drag reduction. A study suggests the formation of polymer films inside the crude oil’s matrix that lubricates it and allows an effective drag reduction (Storm et al., 1999), but it must not be confused with another type of lubricated flow, the core annular flow (CAF). Commercial drag reducers have not been found to be effective because the single-phase flow is usually laminar to only slightly turbulent. In this work we show the effective viscosity of heavy oils in pipeline flow can be reduced by a factor of 3
4. It is hypothesized that a liquid crystal microstructure can be formed so that thick oil layers slip on thin water layers in the stress field generated by pipeline flow. Storm et al. (1999) conducted experiments in a 1 1/4-in. flow loop with Kern River crude oil and a Venezuela crude oil BCF13 are consistent with this hypothesis. The effect has also been demonstrated underfield conditions in a 6-in. flow loop using a mixture of North Sea and Mississippi heavy crude oils containing 10% brine. The most important requirement is that the drag reducing additive should be soluble in the crude oil and for the case of polymers, it is known that the following properties influence their performance: high molecular weight (M . 1,000,000 g/mol), shear degradation resistance, quick solubility in the fluid, and stability against heat, light, chemical and biological agents. One type of current generation of drag reducing additives for liquid hydrocarbons consists of ultra-high molecular weight polymers composed of long chain hydrocarbons that act as an intermediate layer between the fluid and the inner wall of the pipe to reduce energy loss caused by turbulence. However, commercial polymeric drag reducers, typically homopolymers or copolymers of alpha-olefins, do not perform well with heavy oils having low API gravities and/or high asphaltene content. Milligan et al. (2011) proposed the use of high molecular weight acrylate-based polymers for drag reduction consisting of latex suspensions product of an emulsion polymerization reaction. It is a system for reducing pressure drop associated with the turbulent flow of asphaltenic crude oil through a conduit. The crude oil has a high asphaltene content and/or a low API gravity. Such reduction in pressure drop is achieved by treating the asphaltenic crude oil with a high molecular weight drag reducing polymer that can have a solubility parameter within about 20% of the solubility parameter of the heavy crude oil. The drag reducing polymer can also comprise the residues of monomers having at least one heteroatom. The percentage of drag reduction reported for heavy oils is in the range of 28%
36% as listed in Table 5.8, which is a significant improvement when comparing with commercial products that attained no drag reduction with heavy oils. Here, the drag reducer is soluble in the crude oil phase and seems to form films or layers inside crude oil’s matrix that allows it to slip and results in a higher flow rate at a constant pumping pressure. This phenomena has also been observed with the use of drag reducer/pentanol mixtures in extra-heavy oils (10 API) and is known as lubricated flow. Here, we must differentiate the latter case from CAF, where the lubricating ring is formed with water and a polymeric additive, as explained below. The Milligan invention has the following options: 1. Introducing a drag reducing polymer into a liquid hydrocarbon having an asphaltene content of at least about 3 weight percent and an API gravity of less than about 26 degrees to thereby produce a treated liquid hydrocarbon. The drag reducing polymer comprises at least about 10,000 repeating units, and a plurality of the repeating units comprise a heteroatom.

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2. Introducing a drag reducing polymer into a liquid hydrocarbon having an asphaltene content of at least about 3 weight percent and an API gravity of less than about 26 degrees to thereby produce a treated liquid hydrocarbon. The drag reducing polymer includes at least one repeating unit having at least one heteroatom, and the viscosity of the treated liquid hydrocarbon is not less than the viscosity of the liquid hydrocarbon prior to treatment with the drag reducing polymer. 3. Reducing pressure drop associated with the turbulent flow of heavy crude oil through a pipeline, wherein the heavy crude oil has an API gravity of less than about 26 degrees and an asphaltene content of at least about 5 weight percent. The method of this embodiment comprises: (1) introducing a drag reducing polymer into the heavy crude oil, wherein the drag reducing polymer comprises at least about 25,000 repeating units; (2) flowing the resulting treated crude oil through the pipeline, wherein the viscosity of the treated crude oil is not less than the viscosity of the heavy crude oil prior to treatment with the drag reducing polymer. 4. Introducing a drag reducing polymer into a liquid hydrocarbon having an asphaltene content of at least about 3 weight percent and an API gravity of less than about 26 degrees to thereby produce a treated liquid hydrocarbon. The drag reducing polymer comprises at least about 10,000 repeating units and has a solubility parameter of at least about 17. 5. Introducing a drag reducing polymer into a liquid hydrocarbon having an asphaltene content of at least about 3 weight percent and an API gravity of less than about 26 degrees to thereby produce a treated liquid hydrocarbon. The drag reducing polymer comprises at least about 10,000 repeating units and has a solubility parameter within at least about 20% of the solubility parameter of the liquid hydrocarbon. The relevant problem in using drag reducing latex additives is the difficulty encountered when dissolving the polymeric material contained in the latex emulsion into the hydrocarbon stream. The polymeric suspensions prepared for injection have a tendency to separate when stored in the field locations and special equipment is needed. The problem of preparing, storing and dissolving such drag reducing polymers has been addressed by forming an initial latex suspension, then modifying it by adding low HLB surfactants and solvents that enhance the dissolution rate in a hydrocarbon stream over the initial latex as suggested by a previous patent (Harris et al., 2008). One additional consideration when using these additives is that they are susceptible to shear degradation when dissolved in hydrocarbons. Thus passage through a pump or severe constrictions in a pipeline can shear the polymer and reduce its effectiveness, in some cases dramatically so. Consequently, it is important that these polymers be poured into the flowing hydrocarbon stream in a form that achieves the needed flow features. The drag reduction of an Iranian crude oil in two-phase flow was studied to simulate the transport of crude oil and natural gas in horizontal pipes (Mowla and Naderi, 2006). In that study, the effect of the presence of a DRA on the pressure drop in cocurrent horizontal pipes carrying slug two-phase flow of air and crude oil is investigated. An experimental setup is erected. The test section of the experimental setup is consisted of a smooth pipe of polycarbonate with 10.3 m long and 2.54 cm ID, a rough pipe of galvanized iron with 8.8 m long and 2.54 cm ID and a rough pipe of galvanized iron with 8.8 m long and 1.27 cm ID. The employing DRA is a

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polyalpha-olefin (polyisobutylene). The percent drag reduction (%DR) is calculated using the obtained experimental data, in presence of the DRA. The results show that addition of DRA could be effective upto some doses of DRA after which the pressure drop is kept constant. A %DR of about 40 is obtained for some experimental conditions. A poly(isobutylene) was employed as the drag reducing additive and it was found that a dosage of 18 ppm was required to keep constant the pressure drop. Authors state that drag reduction increased with pipes of smaller diameter and roughness of pipe’s surface, that is, where turbulent flow exists with a high Reynolds number for the same flow rate. High molecular weight polymers are by far the most efficient drag reducers, but their susceptibility to shear degradation, limits their use. Surfactants show somewhat less drag reducing capabilities than polymers, but their advantage is that drag reduction at fluid velocities over the “critical shear stress,” shear stress at which surfactant’s micelles disappears, is less affected than in the presence of polymers. Indeed, surfactants have the ability to restructure its rod-like microstructures and resume its own drag-reducing capability when the shear stress in the flow decreases to a certain level. The orientation of the largescale orderly rod-like micelle structures, which promote the drag reduction phenomenon, is recoverable on the order of seconds even after being disrupted (Zhou et al., 2006). Zhou et al. (2006) studied drag reduction and heat transfer enhancement in a fully developed two-dimensional water channel flow. Surfactant solutions at different concentrations, namely, 30, 70, 80, and 90 ppm, were used to examine the influence of surfactant additives on the skin friction drag and heat transfer coefficient. The magnitudes of the maximum achievable drag reduction at the above four different surfactant concentrations are about 7%, 30%, 50%, and 55%, respectively. Their results show that there is no heat transfer reduction when 30 ppm of surfactant is added to the flow. With the increase of surfactant concentration to 90 ppm, heat transfer rate was reduced by about 55%. The critical Reynolds number for loss of heat transfer reduction increases with the increase of surfactant concentration. The effect of the low-profile vortex generators on heat transfer rate was examined for the surfactant concentration of 90 ppm. The results show that the averaged Nusselt number2 is enhanced by 180%, 160%, and 150% for the Reynolds numbers of 7000, 12,000, and 16,200, respectively, as compared with that obtained in the surfactant solution without the use of vortex generators and yet the pressure drop penalty for heat transfer enhancement is rather small. Also, drag and heat transfer reduction increases with additive concentration until a maximum reduction is reached (Salem et al., 1998). They conducted pilot-scale experiments to study the effect of a heterogeneous surfactant on the drag and heat transfer coefficient in crude oil pipelines. The effects of surfactant concentration, pipe diameter, Reynolds number, and temperature were studied. An extensive set of data was obtained for heat transfer and friction coefficients for a heterogeneous surfactant known as MDR2000. A wide range of Reynolds numbers was covered and experiments were conducted for many different Prandtl numbers. All drag and heat transfer reduction experiments were performed in the same installation using the same measurement techniques, which facilitates the assessment of the trends caused by the various parameters studied. 2

Nusselt number (Nu) is the ratio of convective to conductive heat transfer at a boundary in a fluid. Convection includes both advection (fluid motion) and diffusion (conduction).

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Typical results showed that the friction coefficient was reduced by half at the optimum concentration. The heat transfer coefficient was reduced even more dramatically. Research of Akron University (Ohio, United States) studied the applications of a heterogeneous surfactant formulation that is formed by a mixture of a 70% of nonionic surfactant and 30% of anionic surfactant (Hellsten, 2002). When a water-soluble polymer and surfactant with addition of salt are mixed in water solution, the specific structures (aggregates) are formed, in which polymer film is formed around micelle. In a pipe flow, such aggregates take preferred orientation, according to minimum resistance principle. When the Reynolds number increases, the aggregates elongate. Thus, the mixture of polymer and surfactant creates synergy. Matras et al. (2008) demonstrated this principle, as shown in Fig. 5.35. The polymer
surfactant structure before flowing is shown in Fig. 5.35. Polymer film is forming around a micelle. That structure is a general accepted model explaining effect of interaction between polymer and surfactant. On a base of that model, experimental results can be interpreted in a simple way. Figs. 5.35
5.37 represent the structures corresponding to flow ranges numbered 2
5 in Fig. 5.36. In a pipe flow, aggregates take preferred orientation according to minimum resistance principle (Fig. 5.36). In their work, poly(ethylene oxide) (PEO)
cetyl trimethyl ammonium bromide (CTAB) complex formation and its effect on drag reduction were studied. It was found that PEO
CTAB aggregates reduced drag much more efficiently than these substances alone. Structure degradation appeared later and the drag reduction existed longer. Moreover, damaged structure could be partly rebuilt. Under flow, such aggregates take preferred orientation according to the minimum resistance principle and reduced drag more efficiently than the additives alone. When the Reynolds number augments and reaches a certain value, called the critical point, the drag reduction caused by the surfactant solution alone disappears, while that of polymer
micellar solution still remains.

5.4.5 Annular and core flow for heavy oil pipelining Another solution for the transportation of highly viscous products by pipeline is based on developing a CAF to reduce the pressure drop in the pipeline caused by friction. The most spread-out way is to blend the crude oil with a light hydrocarbon to decrease the viscosity. In this study, we investigate a technique based on two-phase flow: pipeline lubrication. A thin water film is injected around the internal oil core, which leads to the CAF regime. Water lubricates the heavy oil, and the longitudinal pressure gradient is then largely reduced. In this technique, water is injected in the oil such that it flows as an annular film along the pipe wall while oil flows in the core region as shown in Fig. 5.37. Since the oil does not come in contact with the wall, the wall shear is comparable to the shear encountered during the flow of water only through the pipe. This reduces the pumping power and its cost drastically. This technique saves energy greatly in comparison with the other transportation process. The main idea is that a thin film of water or aqueous solution can be located adjacent to the inner wall of the pipe, “lubricating” the inner core fluid consisting of heavy oil, thus leading to a reduced longitudinal pressure gradient and a total pressure drop similar to moving water (Palou et al., 2011).

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FIGURE 5.35 Hypothetical mechanism of drag reduction (Matras et al., 2008).

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FIGURE 5.36 Curves of friction behavior: friction factor versus Reynolds number, cf* 5 f(Re*); solution before degradation (Matras et al., 2008).

FIGURE 5.37 Schematic of core annular in a horizontal pipe.

Although this technique appears to be very attractive for heavy oil transportation, there are several problems, which need to be addressed before an economic utilization of the phenomenon can be effected, as follows (Ghosh et al., 2009): 1. Establishment of core annular flow to get a reduced pressure drop. Oil water CAF exists over a limited range of fluid velocities and water fraction for a particular diameter of the pipe. Therefore the major challenges before the researcher are to establish and maintain the flow distribution throughout the pipe length. This calls for a proper nozzle design to ensure the pattern at the start of operation and a careful adjustment of the water volume fraction to attain the desirable flow distribution. 2. Retention of water film at the pipe wall. It is often observed that during long hours of continuous flow the oil core touches the pipe wall and fouling occurs, thereby increasing the pressure drop drastically. Fouling depends greatly on the wetting (hydrophilic or hydrophobic) characteristics of the pipe material. Therefore selection of a proper material of construction and modification of wettability characteristics are major concerns of the problem.

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3. Stability analysis. The flow once established is required to be stable over a long period of time and a wide range of velocities. Otherwise the transportation of oil will not be feasible. Hence the range of operating conditions for which the flow is stable should be known or estimated to avoid fouling. Annular flow is one of the regimes presented by a two-phase flow but a full and stable CAF is very rare, so a wavy flow is more likely to be present in the core fluid. This technique has been considered for a long time. In early 20th century, a patent was issued (Isaacs and Speeds, 1904), which mentioned the possibility to pipelining viscous fluids through water lubrication. However, a commercial pipeline dedicated to transportation of heavy oil through annular flow was not in operation until the 1970s (Peysson et al., 2007). The pipeline is operated by Shell near Bakersfield, California, claiming to have transported significant amounts of high viscosity crude oil with water lubrication. Nevertheless, the capillary instability breaks the inner core into slugs at low velocity and stratification occurs in the system. Peysson et al. (2007) experimentally investigated the flow, stop, and restart of a viscous heavy oil with coinjection of water or brine as the lubricant fluid. The tests were conducted in steady laminar flow at moderate flow rates. The results show a pressure-drop reduction of more than 90% compared with the same product without lubrication. These results confirm the effectiveness of the lubricating process for heavy-oil transport. They also measured restart pressure with different salts in the water phase, and we show that in some cases, the restart pressure can be limited. Chilton and Handley (1958) proposed a pipeline system with water injection and extraction units and in order to minimize the water used, the injection is carried out at several points around the circumference of the pipe. They mentioned that the addition of chemicals such as sodium hexametaphosphate to the water increases the water’s ability to adhere to the pipe and displace the oil films without forming an emulsion. Poettmann (1975) invented a process involving the application of an annular ring of relatively inexpensive micellar solution to reduce drag, forming a temporary film over the interior of the pipeline. This substitutes the expensive polymer, replacing with relatively an inexpensive surfactant system. This invention permits the use of relatively inexpensive micellar systems to reduce drag. For forming more temporary films over the interiors of pipelines, the micellar systems can either be maintained on the pipeline wall by repeated injections or they can be permitted to discontinue gradually being absorbed into the liquids being transported. This is particularly useful in commercial pipelines where highly viscous fluids which require such drag reducing films may be followed by highly fluid liquids which do not require such films and which may even tend to destroy gel films. The micellar solution may be either water or oil-external micellar solutions. Older pipelines which have been exposed to crude oils are generally oil-wet, so oil-external micellar solutions will tenaciously stick to the surface of the pipeline and present a smooth surface to the fluid being transported. However, water may combine with petroleum through a pump, forming a high viscosity W/O emulsion. Broussard et al. (1976) invented a solution to the problem of passage of a core-flow system through booster pumps in a pipeline without prior separation of the oil
water fluid. The alternative solution is to add more water or other less viscous liquid after the pump to enable core flow of the resulting emulsion, subsequently the emulsion is broken by applying high shearing forces by means of pipe flow through specialized pipes that restores the annular flow.

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While extensive experimental and analytical studies have been carried out to demonstrate that CAF is a feasible method for the transport of heavy and extra-heavy crude oils and bitumen at ambient temperatures, no attention has been given to the manner in which this flow pattern is to be established in a commercial pipeline. The effectiveness of the commercial use of core flow is related to its adaptability to existing pipeline systems. Establishing annular flow involves not only technical questions but also operational methodologies to increase the flexibility of the method, in particular, the capacity to share the pipeline with other types of fluids that are not in the core flow regime. Zagustin et al. (1988a) disclosed a solution by placing a spherical sealed pig within the pipeline at a desired position. This process for transporting viscous oil in a pipeline comprises placing a spherical sealed pig within the pipeline at a desired position, filling a fraction of the pipeline upstream of the pig with a low viscosity fluid such as water, then initiating core flow of a viscous oil such as a heavy or extra heavy crude oil after the first fraction has been filled. The process permits the core-flowed viscous oil to be transported in the same pipeline with a noncore-flowed fluid. To do this, a second pig is placed in the pipeline intermediate the core-flowed viscous oil and the noncore-flowed fluid and a second fraction of the pipeline intermediate the second pig and the core-flowed viscous oil batch is filled with a low viscosity fluid such as water. Still, establishing annular flow for heavy oil transportation involves significant problems for commercial application as pipeline’s exclusive dedication to annular flow regime, maintaining the stability overlong distances, fouling and corrosion of the pipe walls, and in particular, the difficulties of restarting the flow in case of unscheduled downtime. In any normal pumping operation of crude oil, we can expect interruptions in the process due to mechanical failure, power interruptions, and ruptures in the pipeline or climate concerns. When annular flow is used to transport heavy oil through a pipeline, interruptions in the operation even for relatively short periods of time can lead to the stratification of the two phases. Attempting to restore annular flow by pumping simultaneously a multiphase system with different viscosities creates peaks in the discharge pressure of pumps or along the pipeline. These large pressure peaks can cause major failures in the pipeline as they may exceed the maximum allowable pressure. A basic process for restarting core flow with heavy oils after a long standstill period was also proposed by Zagustin et al. (1988b). This invention relates to a process for restarting the core flow of viscous oil within a pipeline after an interruption in the flow. The process comprises initiating the flow of a low viscosity fluid, preferably water, into the pipeline by means of a pump; gradually increasing the flow of the low viscosity fluid, preferably in a substantially linear manner, until a desired steady state condition and the critical velocity needed to form an annular flow are reached, and initiating the flow of viscous oil into the pipeline after the steady state and annular flow conditions have been reached. Once flow of the viscous oil has been initiated, it is gradually increased either by adjusting a variable speed motor connected to a pump used to create viscous oil flow or by adjusting a control valve in a viscous oil bypass line. The process further comprises minimizing the peak pressure encountered during the restart operation by adding a tensoactive agent to the low viscosity fluid. When the low viscosity fluid is water, the peak pressure is minimized by adding less than about 500 mg/L of a suitable wetting agent into the water. Fig. 5.38 shows the system.

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FIGURE 5.38 Scheme of a pipeline design allowing core flow of heavy oils after a standstill period. Source: Adapted from Zagustin, K., Guevara, E., Nunez, G., 1988b. Process for restarting core flow with very viscous oils after a long standstill period. U.S. Patent No. 4,745,937. 24 May 1988.

It has been found that the maximum pressure encountered during the restart process of the present invention is much smaller than the maximum pressure encountered if the viscous oil and low viscosity fluid pumps are started simultaneously. It is also smaller than the maximum pressure encountered during techniques wherein the low viscosity fluid pump is started at the maximum flow rate. Other advantages to the process of the present invention include the elimination of large pressure fluctuations in the system, the ability to restart core flow after long standstill periods, that is, upto a week, and the ability to create core flow in a relatively short period.

5.5 Digital networking technologies Over the past few years, most SCADA system vendors have enabled digital networking to allow for communications between the host and the remote terminal units (RTUs). This is partially because of the migration, by conventional telecommunications service suppliers, from analog communications to digital communication. The proliferation of available digital networking technologies and the widespread adoption of Internet protocol (IP) networking and the Internet have also boosted the adoption of digital technology. One of the qualities of most digital networking technologies is the ability to support multiple, concurrent communication sessions (conversations) over a single physical communication link and to provide a flat communication architecture. In other words, any computer can directly communicate with any other computer, if this is needed (as when smart RTUs exchange data directly with each other or with multiple hosts). These are both useful capabilities for SCADA systems and are not generally available with conventional analog technologies. A SCADA system owner can use any of the digital networking technologies depending on the desire to use commercial suppliers or to construct a proprietary network. The network-ready SCADA systems and RTUs refer to the systems that support IP networking with one of the currently available IP SCADA protocols: IP-Modbus, IPDNP3.0, ICCP, or UCA2.0. Fig. 5.39 shows the schematic of the SCADA system. Oil pipelines are spread across the ranges from few kilometers to hundreds of kilometers. Maintaining the pipeline with continuous health monitoring is the biggest challenge. A fiberoptic communication backbone is built to collect control data from programmable logic controller (PLC)/remote terminal unit (RTU) and monitor fire and gas systems, heating, ventilation, and air conditioning system, and leakage monitoring. To achieve the above transmission to the central control room, proper bandwidth and fiber-optic availability are the keys. Consolidating the system requirements for above applications is as follows: 1. Remote monitoring, control, and management of oil pipelines from the control center. 2. Uses fiber optics for long-distance transmission of data across the country.

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FIGURE 5.39 Simplified schematic of SCADA system.

3. High-speed redundant ring for high data availability. 4. Rugged design to operate in harsh environments. For successful data transmission, a network consisting of multiple Ethernet switches is needed that can provide multiple ports of gigabit capability for making more bandwidth available. Based on the switches capability, they are able to transfer data overfiber optic in a range of 25
80 km. Synchronous digital hierarchy (SDH) multiplexing one of the popular methods is used for data transfer for such a long distances. Basic communication normally happens this way; data from RTU/PLC is collected by the switch using twisted pair coaxial cable. After that, the output of the switch is converted to data that can be transmitted over fiber optic and sent across to the control room. Apart from transmitting the data from PLC and RTUs, the fiber-optic technology can be used to monitor the pipeline general health and leakages. This is useful where there are extreme weather conditions such as heavy rains and landslides that may impact position of the pipeline and to monitor human intervention accompanied by malicious attempts of tampering the pipeline with intent of theft. A single fiber-optic cable serves as both the sensor and the path for data flow. Sensor cable, lead cable, and optical junction boxes are all optical to reduce maintenance costs. Core functionalities of the SCADA system are as follows: 1. Acquisition of data from field instrument devices via RTU. 2. Processing the field data to detect alarms and other significant process changes. 3. Providing a consistent database of process information about the pipeline and facility.

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4. Presenting the data via easy-to-understand graphical user interface, alarms, treads, and reports. 5. Performing remote control of field devices. 6. Performing system monitoring and diagnosis and taking appropriate actions. 7. Historical archiving of data for recent and long-term historical storage and analysis. 8. Transferring real-time engineering data directly to and from the modeling system such as pipeline application system. 9. Providing system data to management information system (MIS) and supply chain management. 10. Providing integration with geographical information system (GIS) facilities. General fiber-optic cable design is intended to withstand all external influences such as external humidity, side pressures, and multidimensional strains. These are effectively used for sensing extreme temperatures between subzero to above 50 C. Multidimensional strain is monitored using Brillouin scattering that enables a reliable transfer of strain to the optical fiber. Finally, when sensing distributed strain, it is necessary to simultaneously measure temperature to separate the two components. While sensing the strain, temperature has to be measured by installing strain and temperature sensing cables in parallel. It would, therefore, be desirable to combine the two functions into a single packaging.

5.6 Pipeline monitoring system 5.6.1 Oil and gas pipeline types Crude oil and gas pipelines are subdivided according to their function as follows: (1) flowlines, (2) gathering pipelines, (3) transmission (or trunk) pipelines, and (4) distribution pipelines (Kennedy, 1993). Flowlines are installed in oil and gas fields and connect individual wells to field central storage or field processing facilities. They are relatively short (e.g., a few miles) with outer diameter (OD) that ranges in size between 2 inch (50.8 mm) and 6 inch (152.4 mm). Flowlines transport a mixture of crude oil, gas, and water from the well to a tank battery, where these materials are separated. Since they are relatively short, low operational pressures are sufficient for transporting the contents. Gathering pipelines further transport crude oil or clean gas from a tank battery to a larger long-distance transmission pipeline. In some cases they are directly connected to wells. Gathering pipelines have a larger diameter, typically ranging between 4 inch (101.6 mm) and 16 inch (406.4 mm), and higher pressure is required to move their fluids. Pressurization is ensured by means of pumps (for crude oil) or compressors (for gas). Flowlines and gathering pipelines are commonly made of steel, and coated externally to protect them against corrosion (Kennedy, 1993). Since corrosive agents are frequently mixed with crude oil and gas in wells, flow lines may be internally coated against corrosion, or made of some corrosion resistant material such as plastic.

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Transmission (trunk) pipelines transport crude oil to refineries or other storage terminals or they may transport dry clean natural gas to utility companies and other customers. They feature large diameters, typically upto 56 inch (1524 mm) and in some cases even 80 inch (2032 mm). They also extend over very long distances (e.g., several hundred miles). Crude oil transmission pipelines require pumps at points of origin and pumping stations along the pipeline to maintain the pressure required to overcome friction, changes in elevation, and other losses. Gas transmission pipelines also require high pressure, which is ensured by a compressor at the beginning of the pipeline and compressor stations along the pipeline. Thus, transmission pipelines are designed to support high operational pressures. They are made of steel, externally coated to protect them against corrosion; such pipelines are also typically buried (Kennedy, 1993). However, in some cases, when burying is impossible for cost or technical issues, the pipelines are built on the surface and may be additionally coated for thermal insulation (e.g., Trans Alaska Oil Pipeline). In some cases, gas and oil can be simultaneously transported. The design of these two-phase pipelines is complex due to several flow regimes that can occur inside the pipelines causing unpredictable pressure drops. Therefore two-phase pipelines are used only when there is no economical or practical alternative (e.g., offshore pipelines). Distribution pipelines are part of the network that delivers the gas to end users such as residential houses, industry, and businesses. They have small diameters and are commonly made of plastic. Refined product pipelines transport oil products such as gasoline, aviation gasoline, diesel, LNG, and home-heating oil from refineries to storage terminals or utility companies. They can be hundreds of miles long, but they generally have smaller diameters, commonly around 8
16 inch (203.2
406.4 mm); however, they can also be as big as 26
28 inch (660.4
711.2 mm). Refined product pipelines operate under higher pressure than transmission pipelines. In some cases, two different liquid products can be transported, with or without the use of a separator. An important property of oil and gas pipelines is that they transport pressurized fluids. That is why these pipelines are made of steel and buried when possible. The pipelines are constructed by assembling a large number of individual pipe elements called line pipes (Kennedy, 1993). Depending on the application, various diameters, and grades of steel (with different chemical compositions and physical properties) can be used according to specifications frequently proposed by trade associations [e.g., API in the United States (API, 2011)]. In general, two types of line pipes are manufactured: seamless and welded. The former is made without longitudinal welds, while the latter has one or two longitudinal seams, or even spiral seams along their lengths. Metallic line pipes are externally protected against corrosion with a special coating (e.g., coal tar enamel and fusion-bonded epoxy), and the coating is additionally protected against mechanical damage using heavy paper wraps, plastic wraps, composite wraps and, in the case of offshore applications, concrete. Line pipes are internally protected against corrosion only if they transport corrosive materials (e.g., flowlines). Line pipes are joined in the field to form a continuous pipeline. The joints are realized by (1) welding (the most common), (2) threaded coupling, in rare cases by (3) bell-andspigot, and (4) flanged joints. Trunk and flow lines are pipes connecting the wells with the treatment plants. Flow lines are the connection from the well itself, to either a treatment

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plant or a gathering station. The trunk lines are usually the bigger lines. They carry often a lot of oil to the final treatment. Depending on the characteristic of the crude, the problems faced in these lines are as follows: 1. 2. 3. 4. 5.

waxing; corrosion; scaling/fouling; sludge; viscosity.

The above factors make a pipeline vulnerable to leaks. Safe operations of pipelines can be easily threatened by different factors such as time-dependent degradations (corrosion, oxidation, creep, etc.), construction defects, or static or dynamic loads originating from outside and inside of the pipelines and related to environmental issues (severe temperature conditions). More significantly, during the transportation of oil and gas, impurities such as carbon dioxide or water can cause corrosion on the inner wall of the pipelines. Pipelines are the common agents used for the transportation of fluids, such as oil and gas, from one place (source) to another (customer). The pipeline is one of the most energyefficient, reliable, and economical ways to transport fluids overlong distances in the order of thousands of kilometers. The transportation of oil and gas through pipelines has been rapidly increasing in recent years (Ogai and Bhattacharya, 2018). Only in India, for example, more than 13,000 km of oil and gas pipelines have been installed. It has been reported that, considering the current trend, by the end of 2020, India will install approximately 16,000 km of oil and gas pipelines, additionally (Kar, 2018). Corrosion can lead to a decrease in the effective wall thickness, which may ultimately result in rupture or leakage (Adegboye et al., 2019). Corrosion defects are the most predominant cause of such pipeline failures, which may exist in various forms such as deposit corrosion, cavitation corrosion, uniform corrosion, and pitting corrosion. Corrosion accounts for about one quarter to two thirds of the total downtime in industries related to pipelines (Ossai et al., 2015). In the last few decades, pipeline inspection gauges (PIGs) have become more prevalent for in-line inspection (ILI) and nondestructive evaluation of the pipelines (Xie and Tian, 2018). The advanced versions of these autonomous systems, also called “smart PIGs,” can move inside pipelines and measure irregularities that may represent corrosion, cracks, joints, deformation (e.g., dents and pipe ovality), laminations, or other defects (e.g., weld defects) in the pipeline. The most common ILI methods that have been installed on smart PIGs and confirmed to be successful for pipeline inspection are magnetic flux leakage (MFL) (Afzal and Udpa, 2002), ultrasonic transducer (UT) (Salama et al., 2013), electromagnetic acoustic transducer (EMAT) (Hirao and Ogi, 1999), and eddy current (EC) (Nestleroth and Davis, 2007). However, certain constraints seriously limit the practicality of the aforementioned methods. In the MFL method, for instance, it is very difficult to effectively saturate the entire cross-section of the pipeline with magnetic flux, and also the servicing process involves frequent calibration and complete analysis. Moreover, the method is not suitable to inspect nonferrous pipelines. The UT method works well in liquid pipelines; however, the application in gas pipelines is not common since it requires liquid coupling between the transducer and the surface of the pipeline. UT is more suitable for thick-wall pipelines rather than thin-wall pipelines (less than 7 mm). Echo loss is

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another major challenge reported in the literature. The EMAT method cannot be used in nonconductive materials such as plastics or ceramics, and it is not suitable for long pipeline inspection, which requires high power and complex signal processing in real time. This method faces challenges for high-speed scanning in pipelines, and it can be applicable up to 2.5 m/s. The EC method requires deep magnetic penetration in ferrous pipelines, and the major drawback is the spacing problem, which occurs while mounting the sensor array on the circumference of the smart pig. In addition, recently, a few ILI methods have also been developed for the inspection of pipelines such as closed-circuit television (CCTV) and mechanical contact probe (MCP). In the case of the CCTV method, the high power supply and lack of visibility inside the long pipelines are the drawbacks. The MCP method can inspect only convex defects such as deposit corrosion. It is not suitable for cavity corrosion or metal loss corrosion, and the friction involved in the inspection process is a major risk. Sampath et al. (2019) presented a new, real-time, noncontact method for the inspection of internal corrosion defects in gas pipelines using an optical sensor array. The method utilizes an optical sensor array consisting of emitter elements, light emitting diodes (LEDs), receiver elements, and light dependent resistors (LDRs). The output signal is further processed with a discrete wavelet transform (DWT) for noise cancellation and feature extractions. The estimated lengths and heights of defects for different physical parameters are investigated. The parameters include inspection speed and lift-off (referred to as the distance between the pipeline surface and the sensor surface). The preliminary experiments are conducted successfully based on the installation of the proposed method on an inhouse developed smart pig. The proposed method has significant capabilities and the potential to overcome the aforementioned limitations of the conventional and current ILI methods. The significance of the developed system lies in being a noncontact, real-time, potential method for ILI application. Following parameters should be monitored: 1. Wax content. Paraffin wax refers to a mixture of alkanes (saturated hydrocarbons) with the general molecular formula CnH2n12. For paraffin usually, n is within a range of 18
32. For paraffin wax, the one found in oil pipelines, n can be upto 75. The solidification point for hard paraffin is between 50 C
60 C. When transporting the crude through the piping system, solidifying paraffin wax can become a problem. It sticks to the inner piping walls and steadily reduces its cross-section. The crude in the well has a temperature that is over the solidification point of the paraffin wax. Thus it is fluent when being pumped up. Along with the transportation, through the pipes, the crude cools down, which is where problems can start. Especially in subsea lines, where the ambient temperature is particularly cool, waxing has to be avoided. Temperature management is a crucial part of engineering around oil wells. It has to find the perfect balance between energy efficient heating (which can be costly) and ensuring the flowability of the crude (also a cost factor in terms of waxing). The consistency of the crude, the length of the piping system, and seasonal changes of temperature need to be taken into account. Despite all effort, waxing is found in all lines of the piping system from the well to the treatment facilities further downstream. This makes regular cleaning necessary, especially in the cold months. The cleaning in the well is done mechanically, which requires downtimes of the well and causes a loss of production during the time

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needed. The pipes are cleaned mechanically by pigging (see also video) or by heating the wax for example with steam or hot oil. The melted wax can now flow downstream. Corrosion in the Piping System. Corrosion is seen as one of the biggest problems for the assets in the Oil and Gas industry. Most of the leaking and malfunctions in machines are caused by corrosion. Certain machines and pipes have a lifetime of fewer than 2 years, due to aggressive substances in the hydrocarbon. Constantly exchanging parts causes exorbitant costs. Nowadays, high-grade steels are used in order to avoid the risk of corrosion. Often this is only done piece by piece, so some parts of the system are more susceptible to corrosion than others. Additionally, the composure of the crude can change overtime and with it its impact on the tubing’s surface and the corrosion Crude oil often contains a high proportion of water, which causes corrosion in pipes. Water is used to pressurize the oil reservoir using special water injection wells. Produced water, that is, water from the oil well, is used. Seawater or brackish water, near the sea or at offshore locations. Many of these waters even exacerbate the problems. There are microorganisms or other corrosive components in the water. All of them contribute to the problem. Corrosion due to H2S generation is also common. Such is the case in presence of sulfate-reducing bacteria (SRB). SRB are anaerobic bacteria, which are able to survive in crude oil. They are causing various problems in pipelines and machines. These bacteria feed on the sulfate of the steel and produce H2S as a metabolic product. They not only weaken the structure of the steel but also increase the risk of destructive corrosion. Once there is pitting in the pipe, the bacteria settle in this environment and even increase the problem. Here they live and reproduce undisturbed spreading in the whole system. Corrosion due to CO2 is also common. It is found in water applications. Limescale in Wells, Pipes and Machines. Incrustations which sediment from the liquid in the pipe and machine are often limescale. The lime origins either from the crude itself or the water which is part of the crude. Over time the limescale builds up at the inner surface of the pipe and thus slowly decreases the cross-section of the pipe. Without counteractive measures, the pipe will be blocked completely. Sludge formation. “Sludge” is the generic term for all types of sediments that can be found in a pipeline. In an oil or gas pipeline, this can be lime, corrosion, wax, tar, asphaltene, sand, or bacteria. Usually, this sludge can be removed by pigging. The pig is placed in the pipeline at the beginning of the line. The pig is pushed all the way through the pipe by the oil or gas. The pig is designed to clean the pipe walls as it travels through the pipe and remove all the dirt or sediment at the end of the line. The amount of sludge being pushed out of the pipe can on long and big pipelines easy accumulate to several 100 kg. This is, of course, dependent on the frequency of pigging and the size of the pipe. Viscosity blockage. Oil viscosity is a strong function of temperature. Even an otherwise mobile oil can become stagnant. Especially tar or asphaltene, increase the viscosity of crude oil. The higher the viscosity, the more difficult it is to transport through a pipe. Pumping highly viscous liquids can be very energy-intensive and wearing for machines and pipes. Similar blockage can occur with emulsions as well. Because emulsion stability is also a function of temperature, it is important to monitor temperature in order to predict potential breakage of emulsions as well as thickening of the effluent.

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6 Advances in pipeline designs 6.1 Introduction The most important aspect of pipeline design is safety. Most innovations have focused on the ability of pipelines to transport fluid with the minimum risk of leakage. This is particularly acute for gas transport. Conventionally, authorities instruct operators of gas pipelines to operate the lines so that the risk of a gas leakage during a 1-year period lies within a given safety level. The authorities’ required instructions vary from country to country, but will in all cases impose instructions as to how a gas pipeline shall operate. A typical safety level is that the yearly probability of a leakage and to exceed a given pressure within a margin of 2 bar, shall be less than 1 3 1023, in total for all sources of high pressure and all incidents that may occur during the operation of the pipeline. In order to comply with the instructions, a safety device or safety unit is arranged in connection with the pipeline. The components, which may be used in connection with the safety device, must be approved by the authorities to have a reliability that meets the safety level. A crucial consideration in the connection with the current system is that the gas pipeline and all of the equipment determining safety must be within a given total safety level, which is why it is not relevant to use methods or components that are not approved for that safety level. There are a number of process control systems and leakage detection systems which are not useful in relation with a safety device in connection to a gas pipeline. Recently, the focus of innovations in pipelines has expanded from finding new ways to safeguard the integrity of pipelines and reduce their environmental footprint to getting the best value for their resources. The following topics are considered to be high priority among pipeline companies.

6.1.1 High-fidelity dynamic sensing High-fidelity dynamic sensing (HDS) technology is set to become the new global standard for pipeline monitoring. HDS uses specialized fiber optics (not to be confused with telecom fiber optics) fully distributed along the pipeline to sense every centimeter so operators can know exactly where a leak occurred or where there is potential for a leak. HDS sensing is a 24/7 activity with a level of accuracy that can detect a pinhole leak. This remains an emerging field with wide range of applications (St-Pierre et al., 2014).

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6.1.2 Satellites and pipeline safety For pipeline operators, protecting pipelines from the geohazards that can cause damage is a high priority. Geohazards, such as landslides, seismicity (earthquakes), or river erosion, may occur in certain geographical areas. Pipeline operators use satellite-imaging technology to detect and monitor ground movements as small as a few millimeters per month—long before they can create enough force to compromise the pipeline. Satellite imaging of the Earth’s surface is of sufficient public utility that many countries maintain satellite imaging programs. The United States has led the way in making these data available for scientific use. Some of these programs are: 6.1.2.1 Corona The CORONA program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency (CIA) Directorate of Science & Technology with substantial assistance from the US Air Force. The type of imagery used was wet film panoramic and it used two cameras (AFT and FWD) for capturing stereographic imagery. CORONA was the nation’s first photo reconnaissance satellites, operating from August 1960 until May 1972. The program was declassified at the request of the Central Intelligence Agency in February 1995. The Index of the Declassified CORONA, ARGON, and LANYARD Records are available (Website 1). 6.1.2.2 Landsat Landsat is the oldest continuous Earth-observing satellite imaging program. Launched by NASA and the USGS, Landsat-8 offers 30 m resolution satellite imagery across the globe. Thanks to Soar.Earth, you can access it for free. Optical Landsat imagery has been collected at 30-m resolution since the early 1980s. Beginning with Landsat 5, thermal infrared imagery was also collected (at coarser spatial resolution than the optical data). The Landsat 7, Landsat 8, and Landsat 9 satellites are currently in orbit. Free downloads are available from Website 2. 6.1.2.3 MODIS MODIS has collected near-daily satellite imagery of the Earth in 36 spectral bands since 2000. MODIS is onboard the NASA Terra and Aqua satellites. The MODIS Image of the Day section highlights a new MODIS image every day. After a week, Images of the Day become part of the Image Gallery, which is powered by NASA’s Visible Earth image archive. The Image Gallery opens in a new browser window, where one can preview and search thousands of archived MODIS images. These are available from Website 3. 6.1.2.4 Sentinel The ESA (European Space Agency) is currently developing the Sentinel constellation of satellites. Currently, seven missions are planned, each for a different application. Sentinel-1 (SAR imaging), Sentinel-2 (decameter optical imaging for land surfaces), and Sentinel-3 (hectometer optical and thermal imaging for land and water) have already been

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launched. The following satellites are available and data are freely available to the public (Website 4). Sentinel-1 SAR Sentinel-2 MSI Sentinel-3 OLCI Sentinel-3 SLSTR Sentinel-3 Synergy Sentinel-3 Altimetry Sentinel-5P TROPOMI 6.1.2.5 Aster ASTER is an imaging instrument onboard Terra, the flagship satellite of NASA’s Earth Observing System (EOS) launched in December 1999. ASTER is a cooperative effort between NASA, Japan’s Ministry of Economy, Trade and Industry (METI), and Japan Space Systems (J-space systems). ASTER data is used to create detailed maps of land surface temperature, reflectance, and elevation. The coordinated system of EOS satellites, including Terra, is a major component of NASA’s Science Mission Directorate and the Earth Science Division. The goal of NASA Earth Science is to develop a scientific understanding of the Earth as an integrated system, its response to change, and to better predict variability and trends in climate, weather, and natural hazards. The ASTER instrument provides the next generation in remote sensing imaging capabilities compared with the older Landsat Thematic Mapper, and Japan’s JERS-1 OPS scanner. ASTER captures highspatial-resolution data in 14 bands, from the visible to the thermal infrared wavelengths; and provides stereo viewing capability for digital elevation model creation. As the “zoom lens” for Terra, ASTER data are used by other Terra and space-borne instruments for validation and calibration. The site is accessible in Website 5, in which the following data are available. Land surface climatology—investigation of land surface parameters, surface temperature, etc., to understand land
surface interaction and energy and moisture fluxes. Vegetation and ecosystem dynamics—investigations of vegetation and soil distribution and their changes to estimate biological productivity, understand land
atmosphere interactions, and detect ecosystem change. Volcano monitoring—monitoring of eruptions and precursor events, such as gas emissions, eruption plumes, development of lava lakes, eruptive history and eruptive potential. Hazard monitoring—observation of the extent and effects of wildfires, flooding, coastal erosion, earthquake damage, and tsunami damage. Hydrology—understanding global energy and hydrologic processes and their relationship to global change; included is evapotranspiration from plants. Geology and soils—the detailed composition and geomorphologic mapping of surface soils and bedrocks to study land surface processes and Earth’s history. Land surface and land cover change—monitoring desertification, deforestation, and urbanization; providing data for conservation managers to monitor protected areas, national parks, and wilderness areas.

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6.1.2.6 Meteosat The Meteosat-2 geostationary weather satellite began operationally to supply imagery data on 16 August 1981. Eumetsat has operated the Meteosats since 1987. EUMETSAT currently operates the Meteosat-9, -10, and -11 in geostationary orbit (36,000 km) over Europe and Africa, and Meteosat-8 over the Indian Ocean. The Meteosat satellites are operated as a two-satellite system providing detailed full-disk imagery over Europe and Africa every 15 minutes and rapid scan imagery over Europe, every five minutes. Meteosat imagery is crucial for nowcasting, which is about detecting rapidly developing high impact weather and predicting its evolution a few hours ahead, in support of the safety of life and property. Observations are also used for weather forecasting (as input to numerical weather prediction models), and for climate monitoring. The Meteosat visible and infrared imager (MVIRI) is a three-channel imager: visible, infrared and water vapor. It operates on the first-generation Meteosat, Meteosat-7 being still active. The 12-channel Spinning Enhanced Visible and Infrared Imager includes similar channels to those used by MVIRI, providing continuity in climate data over three decades; Meteosat Second Generation. The flexible combined imager on Meteosat Third Generation will also include similar channels, meaning that all three generations will have provided over 60 years of climate data. 6.1.2.7 GeoEye This is a private satellite. GeoEye’s GeoEye-1 satellite was launched on September 6, 2008 (Shall, 2008). The GeoEye-1 satellite has a high-resolution imaging system and is able to collect images with a ground resolution of 0.41 m (16 in.) in panchromatic or black and white mode. It collects multispectral or color imagery at 1.65-m resolution (about 64 in.). GeoEye Inc. successfully launched into space the GeoEye-1 satellite, which provides the US government, Google Earth users, and others the highest-resolution commercial color satellite imagery on the market. GeoEye-1 is able to capture images at 0.41-m (16 in.) resolution in black and white and 1.65-m (5.5 ft.) resolution in color, but under current government rules, the company can only offer the public 0.5-m (1.64 ft.) images. The satellite takes digital images of the Earth from 423 miles away and moving at a speed of about 4 1/2 miles per second. GeoEye’s other satellites provide images to Google, Microsoft, and Yahoo, but Google will be its only online-search mapping customer. The new color imagery means that Google Earth and Google Maps users would have access to more detailed images after the new imagery are loaded into Google. 6.1.2.8 Maxar Maxar’s WorldView-2 satellite provides high-resolution commercial satellite imagery with 0.46-m spatial resolution (panchromatic only). Similarly Maxar’s QuickBird satellite provides 0.6-m resolution (at nadir) panchromatic images. Maxar’s WorldView-3 satellite provides high-resolution commercial satellite imagery with 0.31-m spatial resolution. WVIII also carries a shortwave infrared sensor and an

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atmospheric sensor. WorldView-3 (WV 3) is a commercial Earth observation satellite owned by DigitalGlobe. It was launched on August 13, 2014 to become DigitalGlobe’s sixth satellite in orbit, joining Ikonos which was launched in 1999, QuickBird in 2001, WorldView-1 in 2007, GeoEye-1 in 2008, and WorldView-2 in 2009. 6.1.2.9 Airbus intelligence Ple´iades constellation is composed of two very-high-resolution (0.50-m pan and 2.1-m spectral) optical Earth-imaging satellites. Ple´iades-HR 1A and Ple´iades-HR 1B provide the coverage of Earth’s surface with a repeat cycle of 26 days. Designed as a dual civil/military system, Ple´iades will meet the space imagery requirements of European defense as well as civil and commercial needs. Ple´iades Neo is the advanced optical constellation, with four identical 0.30-m resolution satellites with fast reactivity (Website 6). 6.1.2.10 Spot image The three SPOT satellites in orbit (Spot 5, 6, and 7) provide very-high-resolution images: 1.5 m for panchromatic channel, and 6 m for multispectral (R,G,B,NIR). Spot Image also distributes multiresolution data from other optical satellites, in particular from Formosat-2 (Taiwan) and Kompsat-2 (South Korea) and from radar satellites (TerraSar-X, ERS, Envizat, Radarsat). Spot Image is also the exclusive distributor of data from the high-resolution Pleiades satellites with a resolution of 0.50 m. The launches occurred in 2011 and 2012, respectively. The company also offers infrastructures for receiving and processing, as well as added value options. 6.1.2.11 Planet’s RapidEye In 2015, Planet acquired BlackBridge, and its constellation of five RapidEye satellites, launched in August 2008. The RapidEye constellation contains identical multispectral sensors which are equally calibrated. Therefore, an image from one satellite will be equivalent to an image from any of the other four, allowing for a large amount of imagery to be collected (4 million km2 per day), and a daily revisit to an area. Each travel on the same orbital plane at 630 km, and deliver images in a 5 m pixel size. RapidEye satellite imagery is especially suited for agricultural, environmental, cartographic, and disaster management applications. The company not only offers their imagery, but consults their customers to create services and solutions based on analysis of this imagery. The RapidEye constellation was retired by Planet in April 2020. 6.1.2.12 ImageSat international Earth Resource Observation Satellites, better known as “EROS” satellites, are lightweight, low Earth orbiting, high-resolution satellites designed for fast maneuvering between imaging targets. In the commercial high-resolution satellite market, EROS is the smallest very high-resolution satellite; it is very agile and thus enables very high performance. The satellites are deployed in a circular sun-synchronous near polar orbit at an altitude of 510 km ( 6 40 km). EROS satellites imagery applications are primarily for intelligence, homeland security, and national development purposes but they are also employed in a wide range of civilian applications, including mapping, border control, infrastructure planning, agricultural monitoring, environmental monitoring, disaster response, training and simulations, etc.

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EROS A—a high-resolution satellite with 1.9
1.2 m resolution panchromatic was launched on December 5, 2000. EROS B—the second generation of very-high-resolution satellites with 0.70-m resolution panchromatic, was launched on April 25, 2006. 6.1.2.13 China Siwei GaoJing-1, also known as SuperView-1 is a constellation of Chinese civilian remotesensing satellites operated by Beijing Space View Tech Co Ltd. The constellation initially consisted of two satellites. They operate at an altitude of 500 km and provide imagery with 0.5-m panchromatic resolution and 2-m multispectral resolution. The swath width is 12 km and the descending node time is 10:30 am. The constellation possesses high agility and runs with multiple collection modes including long strip, multiple strips collect, multiple point targets collect, and stereo imaging. The maximum single scene can be 60 3 70 km. These satellites were spaced by 180 degrees on the same orbit. The first pair was launched on December 28, 2016 on a CZ-2D rocket. A launch mishap left these satellites in a lower than planned orbit. The satellites used their own propulsion to raise their orbit to the planned height, although at the expense of lifetime. A second group of two satellite of this type was launched in early 2018, bringing the constellation to four satellites phased 90 degrees from each other on the same orbit. Documentation of this satellite is available on Website 7.

6.1.3 Carbon capture With renewed interest in environmental sustainability, the oil and gas industry is developing ways to lower its environmental footprint. In this regard, Canada has led the way. The first such project was designed and implemented in the Weyburn CO2 Miscible Flood Project located in Saskatchewan, Canada, currently the largest carbon capture utilization and storage (CCUS) project in the world. Weyburn utilized CO2 in an enhanced oil recovery (EOR) scheme to capture more barrels of oil from this particular field. While implementing a carbon capture and storage (CCS)-EOR project was the next logical step in maximizing oil recovery rates for the company, this opportunity allowed the project team to become pioneers in the field of CCUS (Cole and Itani, 2013). There has been a transition from the term CCS to the term CCUS as prohibitive costs have caused many carbon capture projects to fail, which has led to a conclusion that the CO2 must be utilized for EOR or fertilizer production to make such projects economical. This project, launched in 2000 and continuing through to 2012, studied carbon dioxide (CO2) injection and storage into two depleted oilfields in southeastern Saskatchewan. The first phase, completed in 2004, sought to predict and verify that the Weyburn oil reservoir could securely and economically contain CO2. The second phase sought to expand upon the work of the first, and help to recommend a framework for the measurement and monitoring of stored CO2, and to encourage implementation of geological storage on a worldwide basis. The Weyburn project unlocked 155 million barrels of light oil

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reserves while storing 45 million barrels of CO2; both significant and positive outcomes. Weyburn was operational in December 1999, and it initially took 5000 tons of CO2 a day from the Dakota Gasification Company facility in Beulah, North Dakota. The CO2 was considered an industrial waste product from the gasification project at the time. In order to get the CO2 to Weyburn a 300 km pipeline was constructed. In the 1930s, CO2 was considered a waste product that interfered with oil production, and as a result was stranded and vented. Then the government stepped in and facilitated the construction of the first gas trunk line to take natural gas to markets. Conservation regulations followed, and the natural gas pipeline system grew to what it is today a province-wide and countrywide distribution system. Today CO2 is no longer seen as a waste product. Alberta produces over 100 MT of CO2 a year, mainly from coal-fired power generation and the production and refining of oil sands. Alberta’s commitment is to reduce 200 MT by 2050. This is a lofty target given that the CO2 emissions in Alberta are scattered throughout the province, and that the CO2 is typically produced in a very dilute form as exhaust gases which makes it expensive to clean up. The most obvious solution is to produce purer streams of CO2 right from the start, and to build the infrastructure required to move it to places where it can be used and stored. The Alberta Carbon Trunk Line (ACTL) has world’s largest capacity for this type of system. Initially the ACTL will take approximately 5000 tons of CO2 a day from industrial sources, the majority coming from a gasification process. The CO2 will then be transported through a 240-km pipeline to an initial EOR field where it can be used to unlock light oil reserves from depleted reservoirs. CO2 utilization is again the next logical step. In June of 2020, the Alberta Carbon Trunk Line (ACTL) system, the world’s newest integrated, large-scale CCUS system, became fully operational. It comprises a 240-km-long, 16in-diameter pipeline. The ACTL includes participation from multiple partners to capture industrial emissions and deliver CO2 to mature oil and gas reservoirs in Central Alberta for use in enhanced oil recovery and permanent storage. At full capacity, the pipeline can transport up to 14.6 million tons of CO2 per year, which represents approximately 20% of all current oil sands emissions or is equal to the impact of capturing the CO2 from more than 2.6 million cars in Alberta. Not only does the ACTL system remove greenhouse gas from the atmosphere and decrease Canada’s carbon footprint, it uses the captured CO2 to revitalize the light oil industry, leveraging Alberta’s wealth of s storage reservoirs, technical expertise and innovative spirit to create thousands of new jobs, and generate meaningful tax revenue. ACTL is set to be the biggest CCS project in the world and marks the first CSS project to be situated in Alberta. Alberta-based oil and gas company Enhance Energy is developing the project in alliance with Wolf Carbon Solutions, an affiliate of Wolf Midstream, with an estimated $1.2bn investment. The project will gather CO2 from industrial emitters in the Alberta Industrial Heartland in Western Canada and subsequently convey it to reservoirs across Central and Southern Alberta. The CCS project was originally approved by the Canadian Environmental Assessment Agency (CEAA) in September 2010. Construction began at the end of 2018, with operations expected to commence Q4 2019. It is estimated to transport 800 tons per day (tpd) initially, increasing to 4400 tpd by the end of 2019.

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The ACTL has three parts: capture-ready CO2 supply sources (capture), a pipeline (transportation), and an EOR project field (use and storage). The initial suppliers for the ACTL are Agrium, a fertilizer facility, and North West Redwater Partnership Sturgeon Refinery (NWRPSR), a refinery producing low-carbon fuels from bitumen (oil sands) using gasification. These are the first two capture sites for the project. All the major mechanical equipment has been purchased and deliveries are anticipated by the first quarter of 2013 for the Agrium capture site. At the North West site engineering is underway. The difference between these two sources is that the Agrium CO2 is in a wet stream (and therefore the CO2 needs to be dehydrated before use), and that the volumes captured from the NWRPSR are larger than the Agrium volumes. The NWRPSR facility is being built in three phases. The first phase will produce 3500 tons of CO2 a day. If all three phases of the NWRPSR proceed, then the CO2 from this site will reach over 10,000 tons of CO2 a day. Both the Agrium and the NWRPSR streams are high-purity CO2 sources, and combined will total well over 5000 tons of CO2 a day. The ACTL has been routed to maximize access to these reservoirs, which are amenable to EOR. Industry estimates predict that over one billion incremental barrels of oil can be extracted in the province through tertiary recovery techniques such as EOR. An added bonus is that there is also storage capacity for 2
3 billion tons of CO2 in these EOR fields, and other depleted hydrocarbon reservoirs in proximity to the line. The ACTL will help connect the sources of CO2 to the reservoirs in which it can be used. The CO2 emission hubs and the EOR fields able to take the CO2 are shown in Fig. 6.1. The ACTL project is categorized into three parts, namely carbon gathering and capture, the pipeline for CO2 transportation, and EOR and storage. Carbon dioxide will initially be captured from Agrium’s Redwater fertilizer plant and the North West Redwater (NWR) Partnership’s Sturgeon refinery. The $8.5bn Sturgeon refinery was completed in May 2018 and features ten large units, each designed to complete a unique function during the bitumen refining process. The CO2 recovered from the fertilizer plant’s emission streams will be put through inlet cooling, separation, compression, dehydration, and refrigeration in order to produce liquefied CO2. CO2 has successfully been used in the EOR industry in the United States for the past 40 years. Light oil production from EOR projects has topped 350,000 barrels of oil per day FIGURE 6.1 Typical recovery in a light oil reservoir. Source: From NETL, 2011. Improving Domestic Energy Security and Lowering CO2 Emissions with “Next Generation” CO2-Enahanced Oil Recovery (CO2EOR). National Energy Technology Laboratory, Advanced Resources International, June 2011.

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(bopd). In looking at the life cycle of the Wasson Field Denver Unit, primary recovery resulted in the production of 17.2% of the original oil in place (OOIP); secondary recovery 30.1% of the OOIP. The Denver Unit has an additional expected recovery of 19.5% through CO2 EOR. The total of all recovery—primary, secondary, and CO2 EOR—is expected to reach 66.8% of the original oil in place. There are currently over 110 projects and over 4000 miles of CO2 pipelines in the United States. These projects and resulting increased oil production have generated significant revenues and jobs in that country (NETL, 2011) (Fig. 6.2). The production plot shown below illustrates how a field can respond to CO2 injection. This example, for Shell Oil’s Denver Unit in the Wasson Field in West Texas, shows oil and water production, and water and CO2 injection, over 60 years. The primary production portion of the field’s life lasted from 1938 through about 1965. The oil production rate peaked in the mid-1940s and then began to decline as reservoir pressure depleted. The operator initiated pressure maintenance with water injection (waterflooding) in 1965 and oil production rates responded quickly. As the injected water began to break through at the production wells, the volume of water produced also rose rapidly in the 1970s. By the end of 1982, the volumes of water

FIGURE 6.2 Role of CO2 EOR in oil production.

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injected and produced were considerably more than the volume of oil produced. About 2 years after the operator initiated CO2 injection in 1983, the oil production decline began to slow and eventually leveled off. At the end of 1998, one could determine the incremental oil attributable to CO2 EOR by calculating the cumulative difference between the projected decline rate without CO2 injection and the actual production rate. In this example, the volumes of oil produced are significant because the Denver Unit flood is large, with more than 2 billion barrels of oil originally in place (OOIP) and a residual oil saturation after waterflooding of 40%. The typical well pattern is ten producing wells for every three injectors. Currently, the Denver Unit produces about 31,500 barrels of oil per day, of which 26,850 is incremental oil attributable to the CO2 flood. The Wasson Field’s Denver Unit CO2 EOR project has resulted in more than 120 million incremental barrels of oil thru 2008 (Fig. 6.3). At the NWR refinery, CO2 is captured within the gasification hydrogen supply unit, which will use unconverted petroleum bottoms (asphaltene) as feedstock to create synthesis gas (syngas). Rectisol acid gas removal technology is used to condition the syngas and produce more than 3600 tpd of pure CO2. The ACTL pipeline has been specifically designed to last for more than 100 years and will be made of electric resistance welded (ERW) carbon steel. It is set to be a Grade 448, Category II M18oC ERW pipe (Fig. 6.4). A cathodic protection solution is anticipated to be installed as part of the pipeline’s integrity management system.

FIGURE 6.3 US experience (NETL, 2011).

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Liquefied CO2 and syngas gathered from the sites will be pumped into the pipeline at a pressure of 17,926 kilopascals (kPag) and transported to the Clive Nisku and Leduc field reservoirs, which are owned and operated by Enhance Energy. The project is estimated to capture and store more than 1 million tons (Mt) of CO2 a year once fully operational. The project is being funded by Wolf in collaboration with Canada Pension Plan Investment Board (CPPIB), which provided up to $305 m. The ACTL project received a $63 m financing package from the Government of Canada under the Federal EcoETI program and the Federal Clean Energy Fund program. A construction financing of $223 m was granted under the Province of Alberta’s Carbon Capture and Storage Funding Act (2009). Enhance Energy plans to invest approximately $1bn of capital in the development of CO2 storage and EOR over the life of the ACTL. As per the agreement between Wolf and

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Enhance in August 2018, Enhance will own and operate the CO2 utilization and sequestration portion of the ACTL project through its EOR operations; Wolf will construct, own, and operate the CO2 capture and pipeline transportation assets. Various engineering firms are involved to address different aspects of the project. Here is a list of companies that were involved in the ACTL 1. SAW Engineering (Calgary, Canada) provided engineering services for the ACTL pipeline, while Worley conducted the environmental assessment works. 2. BOSS Environmental is responsible for environmental planning for the project and CH2M Hill is expected to provide the required regulatory services. 3. Startec was engaged to supply a refrigeration package to liquefy CO2 at the Redwater fertilizer plant, while Germany-based MAN Diesel & Turbo is supplying the CO2 compressor for the CO2 booster compression unit at the NWR Partnership refinery. 4. KTI is responsible for the supply of valves, while Focus Corporation was engaged as official surveyor for the development. 5. Alberta-based company Surface Search is to conduct the geotechnical assessment works and LandSolutions is undertaking land acquisition process for the project. 6. Fortis Alberta was engaged to construct the power line for the Agrium CO2 facility, while Coronado Gas Coop was contracted to supply a fuel gas pipeline and metering system. 7. Opsco Manufacturing was commissioned to design and fabricate a water removal skid package, while Bilton Welding and Manufacturing was contracted to design and fabricate the wet CO2 inlet separator vessel for the ACTL. The ACTL project is anticipated to create more than 30,000 man-years of direct and indirect employment during its construction and operational phases. It is also expected to offset the impact caused by the equivalent of approximately 2.6 million cars from Alberta’s roads. The CO2 stored in its reservoirs will enable the production of 1 billion barrels of light oil. Oil produced using this CO2 is slated to generate more than $15bn in royalties for Alberta. Wolf Midstream is a partner in the Alberta Carbon Trunk Line (ACTL), which supports CCUS. This will help change its emissions profile and boost the economic opportunities that come from oil and gas production. For pipeline operators, protecting pipelines from the geohazards that can cause damage is a high priority. Geohazards are geological processes, such as landslides, seismicity (earthquakes), or river erosion, that may occur in certain geographical areas. Pipeline operators use satellite-imaging technology to detect and monitor ground movements as small as a few millimeters per month, long before they can create enough force to compromise the pipeline. Prior known safety devices for gas pipelines make use of pressure and temperature measurements. There are no previously known safety devices that also make use of measuring the flow rate at the inlet of the gas pipeline. The gas’ compressibility does not provide an immediate correlation between the flow rate, pressure, and temperature in to the pipeline in relation to what is transmitted out of the pipeline. This is why safety devices suitable for a liquid conducting pipeline are not functional for a gas conducting pipeline.

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6.2 Sustainability of CO2 sequestration and storage 6.2.1 Carbon backbone In a typical instance, the gas pipeline is connected to an existing pipeline system, and the supplying pressure for the gas from the pipeline through an outlet must not exceed a given threshold value, decided by the requirements given for the receiving pipeline system. The connecting of the pipeline and the pipeline system is typically carried out with a so-called hot tap connection. There is a need for a gas pipeline that is particularly suitable for connecting to an existing pipeline system in accordance with the requirements as mentioned above. The most significant development in terms of EOR has been in CO2 projects. Fig. 6.5 shows various US basins have shown increased recovery throughout the last decade. It is over this time that the link between CO2 and global warming has been accepted beyond doubt. The use of CO2 provides one with double dividends. Based on this principle, numerous CO2 projects have surfaced. While theoretically, any CO2 project is both effective and environmentally friendly, a CO2 project cannot be sustainable unless proper process is followed. This aspect will be considered in a later section. The second most important considerations in CO2 floods is the fact that it is considered to be inexpensive, at least in the United States (US$ 1
2/Mscf). In addition, the United States has an existing network of pipelines that can be readily used for the distribution of CO2. There is one significant case study in the Weyburn field of Canada, for which an FIGURE 6.5 CO2 supply and demand in

Alberta Potenal CO2 Capture and Demand

Potenal Capture Sources

Alberta.

Fort McMurray

Potenal EOR Demand Areas Edmonton

Calgary

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entire pipeline was created in order to dispatch CO2 from the United States to Canada. This CO2 was deemed more cost-effective than Canadian CO2 that would have to be extracted from local coal-fired power plants. The project received $1 billion in government grants and more in tax rebates and flagged as the most important CO2 sequestration project of the time. This project was “profitable” only because of the government grant and some 10-fold increase in oil price. This will be discussed in later sections. It is also important to note that the CO2 pipeline system in the US was built in a 30-year (1975
2005) time span when oil prices and tax incentives were sufficiently attractive to ensure security of supply as main drivers. These are viable only because of government assistance in the name of climate change funding and investment. Fig. 6.6 shows the evolution of CO2 projects in the United States and average crude oil prices for the last 30 years. Fig. 6.6 is extracted from Alvarado and Manrique (2010). They used oil prices of the refiner average domestic crude oil acquisition cost reported by the Energy Information Administration (EIA). For reference purposes, crude oil price used in Fig. 6.7 was arbitrarily selected for every month of June except for 2010 (oil price as of March 2010). These CO2 projects led to significant recovery (Fig. 6.8). Although it can be concluded that CO2-EOR (“from natural sources”) is a proven technology with oil prices .$20/bbl, this EOR method represents a specific opportunity in the United States and cannot necessarily be extrapolated to all producing basins around the world. This conclusion is based on the selection criteria listed in Table 6.1. This cannot be generalized to other countries, where different economic, environmental, and technical conditions prevail. From the sustainability point of view, there must be questions that should be asked in the proper sequence. For instance, if the technological feasibility question is asked before the availability of the carbon dioxide, the answer would be irrelevant at best. Similarly, the presence of an existing infrastructure for both CO2 purification and distribution can alter the decision tree. Finally, recent findings indicate that CO2 is quite effective in recovering heavy oil. In fact, with the new incentive of CO2 sequestration, heavy oil reservoirs offer the greatest potential for CO2 injection.

FIGURE 6.6 Evolution of CO2 projects and oil prices in the United States. Source: From Oil & Gas Journal EOR Surveys 1980
2010 and US EIA 2010.

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FIGURE 6.7 CO2 EOR recovery in the United States throughout history. FIGURE 6.8 Alberta government strategy.

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TABLE 6.1 Screening criteria for CO2 projects as used in the United States. ,9800 and .2000

Depth, ft. 

Temperature, F

,250, but not critical

Pressure, psia

.1200
1500

Permeability, md

.1
5

Oil gravity, API

.27
30

Viscosity, cp

# 10
12

Residual oil saturation after waterflood, fraction of pore space

.0.25
0.30

FIGURE

6.9 Natural gas production with CO2 injection schemes. Source: From Khan et al. (2012).

Fig. 6.8 shows the strategy developed by the government of Alberta. This program shows equal importance to conventional and heavy oil formations. Scaled model studies show that heavy oil recovery with CO2 can lead to 70% of the oil in place. This is tremendous considering the fact that the primary recovery of heavy oil is less than 5% and a similar recovery factor with steam flooding would require a significant cost increase while having a bigger footprint on the environment. Fig. 6.9 shows the importance given to CO2-enhanced gas recovery. The use of CO2 injection in enhanced oil recovery is a mature well practice technology. Enhancing gas recovery through the injection of CO2 however is yet to be tested in the field (Hamza et al., 2021). Numerous simulation studies ever since the early work of Islam and Chakma (1993) have appeared to support the high recovery of gas and heavier components from a gas reservoir along with high capacity of CO2 sequestration. Although there are some published simulation studies that have been carried out to comprehend by which process CO2 sequestration in a depleted gas reservoir could lead to enhance gas recovery, none of these studies have ever attempted to manifest the effect of mixing (CO2-CH4) on the recovery

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process prior to depleted reservoir. These studies were mainly aimed to reduce greenhouse gas emission into the atmosphere and sequestrating in a depleted gas reservoir or in an aquifer. In the year 2005, a project by Gas de France Production Netherland was in progress to assess the feasibility of CO2 injection prior to depletion of the gas reservoir (K12-B) for EGR and storage. However, since then no follow-up results have been published on the final gain in reserve recovery (Islam, 2020). Generally, high natural gas recovery factors along with concerns of degrading of the natural gas resource through mixing of the natural gas and CO2 have led to very little interest being shown in CO2-EGR . In terms of sequestration, natural gas reservoirs can be a perfect place for carbon dioxide storage by direct carbon dioxide injection. This is because of the ability of such reservoirs to permeate gas during production and their proven integrity to seal the gas against future escape (Oldenburg, 2003). However, displacement of natural gas by injection of CO2 at a supercritical state has not been studied extensively and is not well understood (Mamora and Seo, 2002). Despite the fact that CO2 and natural gas are mixable, their physical properties such as viscosity, density, and solubility are potentially favorable for reservoir repressurization without extensive mixing. This phenomenon of gas
gas mixing can be controlled by controlling the operating parameters. The injected CO2 in geological formations undergoes geochemical interactions, such as structural, stratigraphic, and hydrodynamic trapping. The injected CO2 is trapped either in the form of physical trapping as a separate phase or as a chemical trapping where it reacts with other minerals present in the geological formation (International Energy Agency, 2010). As time passes, CO2 becomes immobilized in the geological formation as a function of the long time scales. This is known as geological sequestration. Oldenburg (2003) simulated CO2 as a storage gas. The results suggested that CO2 injection as a supercritical fluid allows more CO2 storage as the pressure increases due to its high compressibility factor. Thus, an expansion of the compressed gas is expected due to changes in pressure and temperature. As a result, there will be a point when gas production no longer is economically feasible. In terms of economics, not unsurprisingly, Gaspar (2005) claimed the major obstacle for applying CO2-EGR is the high costs involved in the process of CO2 capture and storage. The experience from oil recovery schemes indicate that the economics look quite different when purity in injected CO2 is not sought. It turns out that the purity doesn’t need to be high and naturally available CO2 or even flue gas would accomplish the same outcome. It is in line with pressure maintenance schemes in oil reservoirs. This option would make CO2 injection appealing without tax incentives as claimed by the IEA (2010). Khan et al. (2012) conducted an economic feasibility study of carbon dioxide into a natural gas reservoir and found the scheme to be economically attractive because of EGR. Fig. 6.9 shows the results of CO2 injection at high and low injection rates. Natural gas production is the highest for CO2 injection at high rate. It is because the mixing is the greatest under high injection rates. However, one should note that this study used a stable displacement front. This is a reasonable assumption because CO2 is more viscous and denser than natural gas. Such results are not expected in oil reservoirs. In terms of overall gas injection for EGR, there are 50 projects in North America that employ sour gas injection for the treatment of natural gas and produced CO2 has been injected in the Dutch sector of the North Sea for years (K-12B gas reservoir).

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Based on the CO2 capture, utilization and sequestration strategy, the government of Alberta has drafted a comprehensive scheme, as shown in Fig. 6.10. “CO2 Backbone” is a network or manifold of pipelines that can be used for transporting CO2 from emission hubs as well as taking CO2 to customer sites. The idea is to create an infrastructure based on the “CO2 culture.” Because CO2 is ultimately a valuable commodity, it is suggested that industrial complexes, including the pharmaceutical industry, be developed along the backbone. This is a powerful template for developing a comprehensive carbon dioxide-based EOR technique. Fig. 6.11 shows locations for various CO2 sequestration projects around the world. These projects are in support of greenhouse gas mitigation. In general, it is accepted that the oil production from individual fields is declining. This notion comes from the fact that natural depletion occurs in every petroleum well. However, both countrywide and globally oil production rates have been rising, apart from interruptions due to political reasons. Fig. 6.12 shows the oil production history of some of the top oil-producing countries. Iran is not included in this figure. However, Iran follows a similar trend and after dropping below 1.5 million bbl/day after the Iranian revolution, the production rate has increased gradually and hovers around 4 million bbl/day today. There are primarily three reasons given for increasing oil recovery: 1. Primary recovery techniques leave behind more than half of the original oil in place. This is a tremendous reserve to forego. 2. Increased drilling activities do not increase new discoveries of petroleum reserve. While this has been replaced with new technological opportunities (e.g., fracking technology creating oil and gas reserve in unconventional reserves), the argument is made to justify EOR. 3. Environmental concern of CO2 emission. Ever since signing the Kyoto Agreement, the US government has led the movement of CO2 sequestration, thereby increasing oil recovery. From the beginning of oil recovery, scientists have been puzzled by the huge amount of oil leftover following primary recovery. Naturally occurring drive mechanisms recover anything from 0% to 70% of the oil in place. In most cases, recovery declines rapidly as viscosity of oil increases. For instance, primary recovery is less than 5% when oil viscosity exceeds 100,000 cp. This is not to say that heavy oil recovery was the primary incentive for EOR, even though most EOR projects in the United States, Canada, and Venezuela involve heavy oil recovery. The primary incentive for EOR is the fact that a typical light oil reservoir would have more than 50% of the original oil in place leftover, while a small investment can recover over 70% of the oil in place. For heavy oil, the room for improvement is much higher. Even though theoretically there is much more recovery potential of heavier energy sources all the way up to biomass (Fig. 6.13), the current recovery techniques are geared toward light oil. This figure shows that natural gas is the most efficient with the most environmental integrity. The argument that is made in this figure is if natural gas, light oil, or any other energy source is burnt without adding artificial chemicals in the stream (e.g., during refining), the entire combustion output is fully sustainable and the CO2 that is produced is 100% recyclable. Each molecule of produced CO2 would end up contributing to the formation of greeneries. Greeneries then end up as biomass, which contributes to enriching the ecosystem. As such, the energy resource is infinite as long as sustainability is maintained.

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FIGURE 6.11

CO2 sequestration demonstration projects around the world.

FIGURE 6.12

Oil production rate history for top oil producers. Source: From EIA (2019).

Within petroleum itself, the “proven reserve”1 is nearly 1.7 trillion barrels (BP, 2018). Out of this reserve, conventional light oil is only 30% (Fig. 6.14). It means that devising a thermal EOR technique is paramount. Any thermal EOR technique involves adding heat, which increases the mobility of the oil exponentially. Fig. 6.15 shows one example of such

1

Proven oil reserves are reserves that are known to exist and that are recoverable under current technological and economic conditions.

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FIGURE 6.13 Key to sustainability in energy management.

FIGURE 6.14 Distribution of the world’s proven reserve.

FIGURE 6.15 Viscosity change invoked by temperature.

exponential decrease in viscosity, which correlates directly with flow rate. The task in hand becomes the delivery of sustainable heat to the formation. The “easy oil,” which is the target of “oil wars” is only miniscule compared to the overall potential, as depicted in Fig. 6.16. Because all energy source utilization techniques are equipped with processing light oil as a reference, the primary focus of EOR has been light oil. A much

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FIGURE 6.16

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Much more oil can be recovered with a double dividend of environmental benefit with sustain-

able technologies.

larger portion of the global oil reserve involves heavy oil, tar sand, shale, and other reservoirs, which require some form of EOR to produce. This reserve can be doubled by using sustainable technology, which increases the overall efficiency and can be utilized in otherwise marginal oil reservoirs. The use of such technology can double the current reserve, even when no new technology is implemented. When, the potential of novel technologies is included a much bigger oil reserve becomes accessible. Most importantly, the exploitation of oil with sustainable technology produces only environment-friendly gases that are readily assimilated with the ecosystem. With it comes the double dividend of economic benefit because all truly sustainable technologies are also the least expensive.

6.2.2 Carbon capture and storage for enhanced oil recovery The capture of CO2 emissions from large point sources, such as power plants or industrial facilities coupled with geologic storage, can contribute to reducing net emissions from industrial or energy conversion activities. If injection occurs in depleted oil or gas reservoirs, this net emission reduction can be coupled with economic benefits from enhanced oil or gas production (NETL, 2011). Injecting CO2 for enhanced oil recovery (EOR) has been practiced for many decades with many success stories to report (Islam, 2020). CO2 used for EOR in the United States (about 1.1 Tcf per year in 2013) is predominantly sourced from naturally occurring CO2 deposits. The IEA’s new global database of enhanced oil recovery projects shows that around 500,000 barrels of oil are produced daily using CO2-EOR today, representing around 20% of total oil production from EOR. EOR with CO2 sequestration in conventional depleted natural gas reservoirs is thought to be

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technically feasible; economic feasibility depends on technology, natural gas prices, CO2 prices, CO2 breakthrough rate, and amount of CH4 recovered (Oldenburg et al., 2004). The costs associated with CO2 sequestration in saline reservoirs also depend on reservoir characteristics that determine injection rate and storage capacity (Eccles et al., 2009). Carbon sequestration in sandstone saline reservoirs holds great potential for mitigating climate change, but its storage potential and cost per ton of avoided CO2 emissions are uncertain. Eccles et al. (2009) developed a general model to determine the maximum theoretical constraints on both storage potential and injection rate and used it to characterize the economic viability of geosequestration in sandstone saline aquifers. When applied to a representative set of aquifer characteristics, the model yielded results that compare favorably with pilot projects of that time frame. Over a range of reservoir properties, maximum effective storage peaks at an optimal depth of 1600 m, at which point 0.18 2 0.31 metric tons can be stored per cubic meter of bulk volume of reservoir. Maximum modeled injection rates predict minima for storage costs in a typical basin in the range of $2 2 7/ton CO2 (2005 US$) depending on depth and basin characteristics in our base-case scenario. Because the properties of natural reservoirs in the United States vary substantially, storage costs could in some cases be lower or higher by orders of magnitude. Eccles et al. (2009) concluded that available geosequestration capacity exhibits a wide range of technological and economic attractiveness. Keller et al. (2008) suggested that although CO2 sequestration is currently an expensive process, future costs may come down and governments may adopt carbon policies that encourage sequestration. A wide range of CO2 sequestration costs—as little as $2 to as much as $77 per metric ton—has been reported in the existing literature (e.g., Eccles et al., 2009, see Table 6.2). Much of the variation is due to differences in problem formulation, boundaries, or formations considered. Tayari et al. (2015) added to the existing body of work estimating geologic CO2 storage costs by developing new estimates of transportation and storage costs associated with moving captured and compressed CO2 from smaller industrial point sources for long-term disposal in depleted Marcellus Shale formations. Organic-rich shales such as the Marcellus are of interest as potential sites for CO2 storage, particularly as carbon capture, utilization, and storage technologies move closer toward commercialization. Because of their low vertical permeability, shale formations are currently considered for use in a geologic storage system as a confining seal or caprock. Shale gas resources are proving to be globally abundant and the development of these resources can support the geologic storage of CO2 to mitigate the climate impacts of global carbon emissions from power and industrial sectors. Studies indicate that the opportunity for geologic storage of CO2 in shales is significant, but knowledge of the characteristics of the different types of shale gas found globally is required. The potential for CO2 sorption as part of geologic storage in depleted shale gas reservoirs must be assessed with respect to the individual geology of each formation. In addition, the introduction of CO2 into shale for enhanced gas recovery (EGR) operations may significantly improve both reservoir performance and economics. Before organic-rich shale basins can be considered viable storage targets, a number of questions relating to the basic geology, the CO2 trapping mechanisms, and their kinetics, injectivity, and enhanced hydrocarbon recovery and monitoring and modeling tools need to be addressed.

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TABLE 6.2 Comparison of results. Source

Cost item

Cost ($/metric ton)

Description

Tayari et al. (2015)

Sequestration

22.4

UTC of injection for Scenario S3 (low distance between wells/high bottomhole pressure)

Tayari et al. (2015)

Sequestration

36.1

UTC of injection for Scenario S1 (medium distance between wells/high bottomhole pressure)

Tayari et al. (2015)

Transportation

38.8

UTC of transportation for Scenario S3 (medium emitter, 100,000 metric ton/year of CO2 emission rate) and straight line distance of 80 km

Tayari et al. (2015)

Transportation

8.5

UTC of transportation for Scenario S6 (large emitter, 500,000 metric ton/year of CO2 emission rate) and straight line distance of 80 km

NETL (2014c)

Sequestration

5.4
49.8

For deep saline aquifer. Mount Simon in Illinois from 5.4 to 7.8 and Rose Run formation in central Pennsylvania from $22.6 to 49.8 per metric ton

NETL (2010a)

Sequestration

5.5
11

For deep saline formations. It can be as high as $25.4 per metric ton

Eccles et al. (2009)

Sequestration

2.4
8.4

For sandstone saline reservoirs at depth of 1600 m

Rubin (2005)

Sequestration

5

For geologic storage

Bachu (2008)

Sequestration

0.5
5.0

For onshore operations

Bachu (2008)

Sequestration

6
12

For offshore operations

Smith et al. (2001)

Sequestration and Transportation

40
77

For saline formations

Rubin (2005)

Transportation

3.2

For 160 km pipeline

Ogden (2002)

Transportation

3.45
5.26

For 100 km pipeline

Heddle et al. (2003)

Transportation

7.82

For 500 km pipeline

Heddle et al. (2003)

Transportation

1.50
2

For 100 km pipeline for a IGCC power plant with 2.16 metric ton per year emission rate

From Tayari et al. (2015).

In contrast to other studies, which focus on injectivity and storage capacity in shale formations or on geochemical interactions and the mechanisms of CO2 trapping (Heller and Zoback, 2014), the variable of interest in the study of Tayari et al. (2015) is the levelized or unit technical cost of transportation and sequestration—the lifetime average cost per unit of CO2 sequestered. A detailed and flexible technoeconomic modeling environment was built for cost analysis, and was coupled with a dynamic reduced order characterization of reservoir response to CO2 flooding (surrogate reservoir model) for detailed representation of CO2 storage and EGR performance. The problem boundary that they considered

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focused on cost evaluation starting at the point in the well’s life cycle where injection begins. This modeling framework was then used to examine costs and cost drivers over a wide range of scenarios considering reservoir characteristics, pipeline transport, injection, enhanced production, and postinjection parameters. The following gives some details of Tayari et al.’s work.

6.2.3 Technoeconomic model Fig. 6.17 provides a simplified schematic of the modeling framework, and outlining the information flow in the technoeconomic model. The economic model is built in the GoldSim environment, which provides a customizable graphical interface (illustrated in Appendix A) and enables the incorporation of economic uncertainties via Monte Carlo methods. The economic model uses as inputs the results from a surrogate reservoir model (SRM; discussed in more detail next), which provides variables of economic interest such as injectivity, production levels, and the composition of produced gas streams. Other inputs to the economic model, such as pipeline transportation costs, do not depend on the SRM. For this study it has been assumed that CO2 is captured from smaller-scale industrial emitters (source), transported via pipeline, and injected in depleted shale gas wells (sink) whose configuration consists of two wells—a dedicated shale gas production well, and a second well that transitions from shale gas production to CO2 injection after a specified period of time (42 years of primary production).

Inputs to SRMs surrogate reservoir model (SRM)

Outputs from SRMs

Inputs

Inputs

Inputs

Inputs

Pipeline Transportation

Injection

Production, Gas Recovery and Separation

Long-term Monitoring and PISC

Outputs

Outputs

Outputs

Outputs

Outputs/ scenario testing results

FIGURE 6.17 Technoeconomic model framework.

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The system boundary considered includes: • transportation (pipeline); • injection, CO2/CH4 mixture separation; and • postinjection site care. Sustainability considerations should be made at each stage of the above points. Costs of CO2 capture from industrial emitters and initial compression before pipeline transport are not considered in this model. Costs associated with CO2 capture have been reported in a wide range, depending on the plant type and capture technology (Table 6.3). It is assumed that the transition from production to injection takes place in year 42 of operation, that is, both wells at a single site are in primary shale gas production for 42 years, at which time natural gas production stops at one of the two wells and CO2 injection begins; production is assumed to continue at the second well. CO2 is assumed to be continuously injected at constant bottomhole pressure from year 42 through year 100, after which time both injection and production cease. Our analysis also focuses only on the drygas region of the Marcellus play, that is, we do not consider condensate production in our analysis. Table 6.4 outlines the main inputs, outputs and features of the model, including its coupling with a surrogate reservoir model (SRM). Outputs from the SRM include time series of variables such as CO2 injection rates, CO2 production rates, and CH4 production rates. These outputs are used as inputs for the technoeconomic model, which calculates separate cost objects for transportation, injection, enhanced production (and separation), and postinjection site activities.

TABLE 6.3 Summary of representative CO2 capture cost estimates. Source

Capture cost ($/metric ton of CO2)

Point source

Oldenburg et al. (2004)

10

Fertilizer

50

Cement

33
72

PC/FGD

21
62

IGCC

Holloway (2008)

18
72

Power plant

Finkenrath (2011)

43
62

Not specified

Heddle et al. (2003)

14.55

Not specified

Ho et al. (2008)

57

Not specified

Rubin (2005)

29
44

PCa

11
32

IGCCb

28
57

NGCCc

Smith et al. (2001)

a

Pulverized coal combustion. Coal-based integrated gasification combined cycle. c Natural gas combined cycle. b

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TABLE 6.4 Structure of the technoeconomic model, inputs, and outputs. Technoeconomic model Inputs

Model structure

Major outputs

SRMs outputs:

Transportation module

Profiles/Scenarios

CH4 production SRM

• Pipeline diameter

• Capital costs

• CH4 production rate CO2 injection SRM

• Pipeline cost Injection module

• CO2 injection rate CO2 production and CO2 breakthrough SRMs

• Wellhead pressure • CO2 pumping cost

• Operating costs • Overall UTC of CO2storage • UTC of transportation • UTC of injection

• CO2 production rate • Percentage of CO2 in production

• Monitoring • Geologic site characterization • Well operation costs

• Some of reservoir characteristics from four SRMs

• UTC of postinjection • UTC of CO2 separation

• Mechanical integrity test

• Pore space acquisition cost • Natural gas revenue

Other required inputs for:

Production module

• Total stored CO2 per well

• Transportation module • Injection module • Postinjection module

• Production revenue, costs • Total transported CO2 • Cost of CH4/CO2 separation • Total produced CH4 Postinjection module • Total produced CO2

• Production module

• Well plugging and monitoring

Scenarios considered herein are defined by different sets of input variables representing various subsurface, emitter, and economic conditions. For each scenario, the technoeconomic model calculates levelized or unit technical cost of individual cost drivers (as listed in Table 6.4, such as unit technical cost of pipeline transportation; injection; pore space acquisition; and postinjection site care). The unit technical cost, as detailed in Section 6.2.3, can be viewed as the CO2 price that would yield a net present value of zero over the injection time horizon (i.e., the price associated with not releasing a unit of CO2 into the atmosphere). The model’s capabilities are demonstrated using scenarios meant to be representative of the dry gas region of the Pennsylvania Marcellus formation. Our modeled unconventional gas reservoir features matrix porosity of approximately 0.09, extremely low permeability of 6
20 μd, and thickness ranges from 40 to 900 ft. (NETL, 2010c). Initial reservoir pressure is between 3000 and 4288 psi (Kalantari, 2013). This study considers production of dry gas (no condensate) with natural gas characterized simply as CH4. This case study assumes that CO2 emissions from nearby industrial point sources are captured and transported by pipeline and injected into horizontal wells for long-term storage in and around the stimulated reservoir volume created by hydraulic fracturing. Historical industrial emissions data from the US Environmental Protection Agency (2011a) were used to characterize the size and spatial distribution of industrial CO2 sources, where industrial sources are taken to exclude large thermoelectric generation facilities (e.g., coal-fired power plants).

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6.2.3.1 Calculation of compressor and pump power requirements After CO2 is separated from the flue gases of a power plant or energy complex (i.e., captured), it must be compressed from atmospheric pressure (Pinitial 5 0.1 MPa), at which point it exists as a gas, up to a pressure suitable for pipeline transport (Pfinal 5 15 MPa), at which point it is in either the liquid or “dense phase” regions, depending on its temperature. Therefore, CO2 undergoes a phase transition somewhere between these initial and final pressures. When CO2 is in the gas phase, a compressor is required for compression, but when CO2 is in the liquid/dense phase, a pump can be used to boost the pressure. It can be assumed that the “cut-off” pressure (Pcut-off) for switching from a compressor to a pump is the critical pressure of CO2, which is 7.38 MPa. Hence, a compressor will be used from 0.1 to 7.38 MPa, and then a pump will be used from 7.38 to 15 MPa (or to whatever final pressure is desired). Pinitial 5 0:1 MPa Pfinal 5 15 MPa Pcut-off 5 7:38 MPa The number of compressor stages is assumed to be five (5Nstage), and the equation for the optimal compression ratio (CR) for each stage is given by Heddle et al. (2003).      (6.1) CR 5 Pcut-off =Pinitial X 1=Nstage where Nstage 5 5 The compression power requirement for each stage (Ws,i) is given by the following equation, which is given by McCollum and Ogden (2006):  h   i ks21 1000 mZs RT in ks ðCRÞ ks 2 1 (6.2) W s;i 5 M ηis ks 2 1 24  3600 Based on some assumptions and CO2 property data from Hendriks et al. (2003), the following values can be used in the above equation: • For all stages R 5 8.314 kJ/kmol-K M 5 44:01 kg=kmol Tin 5 313:15 Kði:e:; 40 CÞ
1000 5 # of kilograms per ton
24 5 # of hours per day
3600 5 # of seconds per hour • For stage 1:

ηis 5 0:75

Zs 5 0:995 ks 5 1:277 These values correspond to a pressure range of 0.1
0.24 MPa and an average temperature of 356K in the compressor.

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• For stage 2: Zs 5 0:985 ks 5 1:286 These values correspond to a pressure range of 0.24
0.56 MPa and an average temperature of 356K in the compressor. • For stage 3: Zs 5 0:970 ks 5 1:309 These values correspond to a pressure range of 0.56
1.32 MPa and an average temperature of 356K in the compressor. • For stage 4: Zs 5 0:935 ks 5 1:379 These values correspond to a pressure range of 1.32
3.12 MPa and an average temperature of 356K in the compressor. • For stage 5: Zs 5 0:845 ks 5 1:704 These values correspond to a pressure range of 3.12
7.38 MPa and an average temperature of 356K in the compressor. Thus, the calculation for compressor power requirement must be conducted five times, since this is the number of stages that have been assumed. Although, this procedure may seem a bit more laborious than simply assuming average values for Zs and ks over the pressure range and using the equation only once, it is prudent to break up the calculation by stage due to the unusual behavioral properties of CO2, which are different at each stage. The compressor power requirements for each of the individual stages should then be added together to get the total power requirement of the compressor. Ws-total 5 ðWs Þ1 1 ðWs Þ2 1 ðWs Þ3 1 ðWs Þ4 1 ðWs Þ5

(6.3)

According to the IEA GHG report (Ogden et al., 2004), the maximum size of one compressor train is 40,000 kW. So if the total compression power requirement (Ws-total) is greater than 40,000 kW, then the CO2 flow rate and total power requirement must be split into Ntrain parallel compressor trains, each operating at 100/Ntrain % of the flow/power.   Ntrain 5 ROUND UP Ws-total=40; 000 (6.4)

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To calculate the pumping power requirement for boosting the CO2 pressure from Pcut-off (7.38 MPa) to Pfinal (15 MPa), the following equation was suggested by McCollum and Ogden (2006) adapted literature.    mðPfinal 2 Pcut-off Þ 1000T10 (6.5) Wp 5 ρηp 24T36 where “m” is the CO2 mass flow rate (tons/day), and the following values can be assumed: ρ 5 630 kg/m3, ηp 5 0.75, 1000 5 # of kilograms per ton, 24 5 # of hours per day, 10 5 # of bar per MPa, 36 5 # of m3 3 bar/hr per kW. The Fig. 6.18. shows the total power requirement for the compressor(s) and pump over a range of flow rates. Notice that the dependence of compression power on flow rate, “m,” is linear, as would be expected from the equation for Ws. Also, notice how small pumping power is relative to compression power. This is because the compressor raises the CO2 pressure from 0.1 to 7.38 MPa—a total compression ratio of 73.8—whereas the pump raises the pressure from 7.38 to 15 MPa—a total compression ratio of only 2.0. 6.2.3.2 Linking surrogate reservoir models to technoeconomic analysis The technoeconomic model is linked to a surrogate reservoir model (SRM) of CO2 injection, storage, and EGR in shale gas formations depleted of natural gas through a period of primary production (Kalantari, 2013). This SRM uses a platform of neural networks and fuzzy logic that are trained to learn the fluid behavior based on realizations from a reservoir simulation

FIGURE 6.18

Power requirement of compressors and pumps as a function of CO2 mass flow rate.

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model. Because of this learned behavior, the SRM is able to generate similar results with high accuracy and much less run time (a fraction of a second per run). The SRM developed for the purpose of this study was trained from a set of reservoir simulations of CO2 injection, storage, and EGR in shale formations representing a range of subsurface system engineering (e.g., bottomhole injection pressure) and geologic (e.g., porosity and permeability) key performance indicators. The simulations were performed using ECLIPSE; the procedure and convergence properties are discussed in detail in Kalantari (2013). The resulting product is a powerful tool to characterize, in a computationally efficient way, reservoir response to CO2 injection for a two-well pattern—one producer well and one producer/injector well—for a time interval of 100 years. The dedicated production well produces CH4 through the entire 100-year simulation interval, while the other well is initially operated in natural gas production, but is converted to a CO2 injection well after 75% of accessible CH4 has been produced (Kalantari, 2013). Based on simulation of gas production from both wells without CO2 injection, the time to 75% reservoir depletion was determined to be 42 years. The SRM, described in detail in Kalantari (2013), essentially represents an expert system that estimates reservoir performance variables based on input specifications provided by the user—within an appropriate range of parameter space corresponding to that which was considered in numerical reservoir simulations and used to train the SRM. SRMs are not full physics reservoir simulations, but capture the important behavior learned from realizations of such a model; SRMs are also not look-up tables or response surface models, but AI-based models that rapidly describe the expected performance of a system given what they have learned about how that system behaves. They provide characterizations that are sufficiently accurate for preliminary technoeconomic assessment (validation information is provided in Kalantari, 2013), and have the advantage of significantly shorter run times that allow for rapid sensitivity and uncertainty analysis. As applied in this study, the SRM is connected to the technoeconomic model via a Dynamic Link Library that enables the user of the technoeconomic model to call the SRMs based on user-defined input parameters and collect results on reservoir response to apply in cost performance calculations. This allows the flexibility to define and customize both economic and subsurface scenarios. When called by the technoeconomic model, the SRMs generate four different reservoir simulation time series: • CH4 production rate for the dedicated production well. • CH4 production rate for the production/injection well during the production phase (before EGR). • CO2 injection rate for the producer/injector well during the injection (EGR) phase. • CO2 production rate for the dedicated production well once CO2 injection commences in the producer/injector well (this last time series determines the CO2 breakthrough). The specific role of the SRM output is described in the following section. 6.2.3.3 Structure of the technoeconomic model The structure of the technoeconomic model consists of four main interconnected modules: transportation; injection; production; and postinjection activities. Each of these four modules performs calculations related to various system elements as described next.

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6.2.3.3.1 Transportation module

This module calculates the costs of transporting CO2 from industrial plant to depleted shale gas wells via a pipeline. The transportation module consists of two submodules: pipeline diameter and pipeline cost. 6.2.3.3.2 Pipeline diameter calculations

An iterative method is used to optimize pipeline diameter (Heddle et al., 2003, McCollum and Ogden, 2006). CO2 pressure at the pipeline inlet (P1) is assumed to be 2200 psig (15.17 MPa) while pressure at the outlet (P2) is assumed to be 1200 psig (8.27 MPa) (NETL, 2010a). Pipeline diameter is calculated for maximum pressure drop equal to (P2
P1)/L, where L is the length of the pipeline. Using this method there is no need for a recompression station and CO2 remains in liquid form in the pipeline. The length of the pipeline is an input variable to the model, while the model outputs an optimized figure for pipeline diameter. The iterative method proceeds according to the steps outlined as: 1. 2. 3. 4. 5.

make an initial guess for pipeline diameter; calculate Reynolds number (Re) of liquid CO2 flow; calculate friction factor; calculate pressure drop; and if calculated pressure drop in step 4 is smaller, then calculated pipeline diameter is complete, else, set a larger pipeline diameter (12 in.) as a second guess for pipeline diameter in step 1 and repeat the process from step 2. Table 6.5 displays a sample result from the pipeline diameter optimization routine. The general equation to calculate Reynolds number is: Re 5

uDρ μ

(6.6)

where u is average velocity of fluid in pipe, m/s; D is pipeline diameter, m; ρ is fluid density, kg/m3; and μ is viscosity of fluid, kg/m/s. The Fanning friction factor (ff) for flow of CO2 in the pipeline can be calculated as (McCollum and Ogden, 2006; White, 2001): 

 ! 6:91  ε 1:11 2 1 (6.7) f f 5 1= 4 21:8log10 Re 3:7D and the Darcy friction factor (f) is given by f 5 4ff TABLE 6.5 Calculated pipeline diameter for 100 miles (160 km) and different CO2 flow rates. CO2 flow rate, metric ton/day (metric ton/year)

1000 2000 3000 4000 5000 6000 8000 10,000 (365,000) (730,000) (1,095,000) (1,460,000) (1,825,000) (2,190,000) (2,920,000) (3,650,000)

Calculated diameter, 6 in

8

10

10

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14

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ε 5 roughness of the pipe, in or m D 5 pipeline diameter, in or m Using general equation for pressure drop in pipelines, pressure drop is calculated (White, 2001) as: ΔP 5

8fV2 Lρ π2 D5

(6.8)

where ΔP 5 pressure drop, Pa f 5 Darcy friction factor, dimensionless V 5 gas volumetric flow rate, m3/s L 5 pipeline length, m D 5 pipeline inside diameter, m ρ 5 density, kg/m3 Given a straight-line distance between source and sink, the pipeline diameter module optimizes pipeline diameter, and then this optimized pipeline information is passed (along with other data) to the pipeline cost submodule. 6.2.3.4 Pipeline cost calculations Pipeline capital and operation and maintenance costs are represented along the lines of the cost model mentioned in NETL (2010a). Uncertainty in deviations from straight-line distance between source and sink is represented in the model through a tortuosity factor probability distribution. Input data to this submodule include the pipeline diameter (calculated in previous submodule), pipeline length, and inlet and outlet pressure (which are defined by the user). Fig. 6.19 presents pipeline capital cost, assuming straight-line distances of 25, 50, 75, and 100 miles (40, 80, 120, and 160 km) and a number of different pipeline diameters.

FIGURE 6.19 Pipeline capital cost as a function of diameter for distances equal to 25, 50, 75, and 100 miles.

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Two observations can be made from information plotted in Fig. 6.19 regarding the economics of pipeline construction. First, given a pipe length and diameter, the average cost of transporting a unit of CO2 declines with the amount of CO2 being transported (since the fixed capital cost can be distributed over a larger number of units of stored CO2). Second, pipeline costs increase somewhat less than proportionally to diameter. We can illustrate this property in Fig. 6.19 by comparing the panels for a 6-inch pipeline and a 12-inch pipeline. Doubling the diameter of the pipeline increases capital costs by around one-third. Thus, a pipeline that is built to handle larger CO2 volumes will, at the margin, have lower incremental capital costs than two smaller pipelines that are built to handle the same large CO2 volume. Economists refer to this second property as “declining long-run marginal cost.” This economic property in particular suggests that coordination in CO2 transportation and pipeline construction (aggregating multiple sources and or sinks into one CO2 transportation infrastructure) should lower overall transportation and sequestration cost. 6.2.3.5 Injection characterization The injection module calculates the costs associated with CO2 injection into depleted shale gas wells, based on scenario-specific injection choices and cost components. The interaction between injection characterization and subsurface performance characterization (as described by the SRM) is particularly important, since injection patterns over the life cycle of the flood are determined based on scenario-specific subsurface parameters. Assuming constant bottomhole pressure during injection, the SRM generates CO2 injection rates for the entire injection horizon (the CO2 injection rate is taken to be zero during the primary production phase). 6.2.3.5.1 Wellhead pressure calculations

At the time of injection, the model assumes that CO2 has pressure of 1200 psi (15.17 MPa) and temperature of 60 F (15.6 C) at the pipeline outlet (injection point), with CO2 injected in liquid form. As the wellhead pressure increases over time, higher pressures will be required to inject liquid CO2 via pumping rather than compressing supercritical fluid. This portion of the technoeconomic model takes the sand face (bottomhole) pressure as an input from the SRM and uses that pressure to estimate the wellhead pressure. We calculate wellhead pressure (P1) as (Hamworthy, 2013):   2 s 2 0:5 Tb P1 2e p2 24 D2:5 (6.9) Q 5 5:747 3 10 F Pb GT f Le Z where F is dimensionless transmission factor, and Le and s are determined by: Le 5 Lðes 2 1Þ=s

(6.10)

s 5 0:0684GðH2 -H 1 Þ=T f Z

(6.11)

gas gravity G 5 ρCO2/ρair 5 MCO2/Mair 5 44.010/28.9625 5 1.52 Q 5 gas flow rate, measured at standard condition, m3/day F 5 friction factor, dimensionless Pb 5 base pressure, 101.35 kPa

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Tb 5 base temperature, (273 1 48.8 C) 5 322 K P1 5 upstream pressure, wellhead pressure, kPa P2 5 downstream pressure, sand face pressure, kPa G 5 specific gravity of gas, dimensionless (air 5 1.00) Tf 5 average gas flowing temperature, (273 1 32.2 C) 5 305.4 K L 5 piping segment length, km Z 5 gas compressibility factor at flowing temperature, dimensionless D 5 pipeline inside diameter, 114.3 mm. H1 5 upstream elevation, 0 m H2 5 downstream elevation, 1981.2 m S 5 elevation adjustment parameter, dimensionless P 5 density M 5 molecular weight M 5 viscosity of gas, Poise Wellhead pressure will be sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi  Pb Q 2 P1 5 es p22 1 GT f Le Z 5:747 3 1024 FT b D2:5

433

(6.12)

Determining the friction factor, requires calculation of the Reynolds number of flow:    Re 5 0:5134 Pb =Tb GQ=μD (6.13) Reynolds numbers exceeding 4000 were calculated, indicating that the flow of gas (CO2) is turbulent. The equation to calculate friction factor in the face of turbulent flow can be derived from Nikuradse friction factor correlation for fully developed turbulent flow in rough pipes (Ikoku, 1984): pffiffi   (6.14) 1= f 5 1:74 2 2log10 2e=D where e is the roughness of the pipe (mm). To calculate average pressure in the vertical portion of the wellbore (for iterative calculations), Menon (2005) suggests the equation instead of taking a simple average of (Pavg 5 (P1 1 P2)/2). Because viscosity (μ) and the compressibility factor (Z) of supercritical CO2 can vary widely due to changes in temperature and pressure, an iterative method is employed to calculate wellhead pressure, which involves the following steps: 1. make an initial guess for wellhead pressure; 2. calculate the average pressure, Pavg; 3. extract the viscosity and the compressibility factor from a lookup table NIST, 2013a, NIST, 2013b; 4. calculate Reynolds number; 5. calculate the friction factor and transmission factor; 6. calculate wellhead pressure; 7. compare the calculated wellhead pressure in step 6 with the wellhead pressure in step 1; if the difference is less than 1%, then the calculated wellhead pressure is final, else,

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set the calculated wellhead pressure in step 6 as a second guess for wellhead pressure in step 1 and repeat from step 2. This process will converge on the wellhead pressure used by the technoeconomic model for a given time step. This iterative calculation is repeated for each time step in our model. 6.2.3.6 Pumping cost calculations Required pumping power (kW) is determined using the equation (McCollum and Ogden, 2006).   (6.15) W p 5 11:57 3 mðPfinal 2 Pcut-off Þ= ρηp Wp 5 pumping power requirement (kW) M 5 the CO2 mass flow rate (metric ton/day) P 5 density of liquid CO2 during pumping 630 kg/m3 ηp 5 efficiency of pump 0.75 Pcut-off 5 pressure at which compression switches to pumping (MPa) Pfinal 5 final pressure of CO2 for pipeline transport (MPa) If calculated wellhead pressure is less than the CO2 pressure at the pipeline outlet (8.27 MPa) then additional pressurization is not required (no pumping power required). Pumps are assumed to run on electric power obtained from the utility and not generated on-site. In the Pennsylvania Marcellus case study illustrated in this paper, we use an electricity cost of 7.73 cents per kWh, which the US Energy Information Administration reports as the average electric rate for industrial ratepayers in Pennsylvania as of 2011 (EIA, 2013). The pump’s capital cost is calculated based on required pumping power, adjusted to study year dollars as described by McCollum and Ogden (2006):     Capital cost for pumping study year dollars 5 1:32 3 103 3 W p 1 0:08 3 106 (6.16) 6.2.3.7 Other injection costs In addition to capital and operation and maintenance costs for pumping CO2, EPA (2010) and TVA (2002) discuss the following injection-related costs for geologic sequestration of CO2, which are considered to be applicable to CO2 sequestration in a depleted shale gas reservoir. 1. Geologic site characterization: These activities are used to evaluate the site for safe CO2 injection before the injection phase (EPA, 2008; EPA, 2010). 2. Monitoring during CO2 injection: Monitoring starts from the beginning of injection to manage health and safety risks, and collect data about flow of CO2 and for reservoir simulation (Reynen et al., 2005; Holloway, 2008). Monitoring costs and operations are based on EPA (2008, 2010) and Benson and Cole (2008). 3. Well operating and mechanical integrity tests: These costs include testing and monitoring activities related to the injection well EPA, 2008, EPA, 2010. 4. Surface and subsurface maintenance: Surface and subsurface maintenance costs are assumed equal to corresponding costs for gas production sites in the EIA (2010) report.

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5. Labor: Direct labor and overhead is calculated from the EIA (2010) report and equals $7425 per year for each well with a depth of 6500 ft. 6. Pore space acquisition: Property rights acquisition costs pertaining to the subsurface area used for CO2storage (NETL, 2010a). Gresham et al. (2010) assumed the cost of leasing pore space at $2
10 per acre per year for private lands and $45
65 per acre per year for state-owned lands for a 100-year time interval (discount rate 5 15% and inflation rate 5 4%). In this study, per-acre pore space acquisition costs are estimated, based on reservoir simulation results for shale-gas formations (estimated total storage area and total storage capacity), and those estimates converted to a per-ton of CO2 stored basis. The total storage area is obtained from the SRM (this represents a boundary condition in the SRM limiting the total area where CO2 can be stored). Total storage capacity is estimated as the integration of the injection rate with respect to time. Multiplying cost of leasing pore space by total area of storage gives the annual pore space cost for the entire area of injection. 6.2.3.8 Production characterization The technoeconomic model assumes a two-well pattern involving a single well which transitions from production to injection and a second well that remains in production during the injection period for the first well. The production module of the technoeconomic model estimates the revenues associated with marketable gas from the production well (the model assumes that the natural gas is compositionally equivalent to CH4, with CO2 the only potential impurity). The production profile of the dedicated production well over the 100-year time horizon is determined using the SRM based on user-specified subsurface characteristics. Detailed illustration of production modeling can be found in Kalantari (2013). Under some scenarios (especially when producer and injector wells are located too close together) CO2 breakthrough in production can occur quickly, in which case injected CO2 will mix with the produced gas. If the content of CO2 in the production stream is sufficiently high (as described in more detail in the following section) the produced gas will require processing to separate CO2 so that production stream will meet the natural gas pipeline standards. The production module thus has two submodules, CH4 production and CO2 separation. 6.2.3.9 Cost of CH4/CO2 mixture separation Natural gas delivered to consumers by pipeline should contain less than 2 mol.% of CO2, and H2S of less than 4 ppm (Shimekit and Mukhtar, 2012). High level of contamination in some natural gas fields (which mainly includes CO2 and H2S) makes production from those reserves infeasible (Golombok and Morley, 2004). Processes to purify the natural gas and reduce the contamination content include gas absorption in liquid solvents; adsorption on solid adsorbents; chemical conversion to another compound; membrane separation; and condensation (Hao et al., 2002). Hao et al. (2002) calculated the cost of purifying natural gas as a function of CO2 and H2S percentage for a single stage with H2S-selective membranes; this cost is in the range of 0.531
0.791 $/Mscf of product for CO2 concentration in feed varying from 0 to 0.4 mol fraction. Bhide and Stern (1993) compared the cost of separating CO2 from natural gas as a

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function of CO2 concentration in feed for different processes. They conclude that if the concentration of CO2 in feed is less than 0.17 mol fraction then DEA (diethanolamine) is a less expensive treatment option than membrane separation; otherwise membrane technology is less expensive. At the aforementioned CO2 concentration, the cost of separation is around 0.29 $/Mscf of feed. According to their results an increase in feed pressure decreases the separation cost of CO2 by membrane and increases separation cost by DEA. Regarding Kohl and Nielsen (1997), process cost of CO2 removal for natural gas flow rate of 60 MMscf/d ranges from 0.1 to 0.55 $/Mscf feed gas for CO2 concentration in feed from 5% to 40%. They concluded that for CO2 concentration in feed less than 15% membrane technology is the cheapest and for CO2 concentration of 15%
40%, two-stage MDEA amine is the cheapest technology (with the cost around 0.22 $/Mscf feed gas). Since reported CO2 separation cost is highly variable for different processes, a triangular distribution with three values (minimum, most likely, and maximum with default value of 0.2, 0.5 and 0.8$/Mscf of feed) is assumed for sensitivity analysis of CO2 separation cost. Revenue from produced CH4 is calculated based on gas production predicted by the SRM over a 100-year time horizon and the assumed price of natural. For cases considered herein, the price of natural gas is assumed to remain constant over the study period. 6.2.3.10 Postinjection site care After injection is complete, postinjection site care (PISC) activities such as well plugging, equipment removal, general site care, and long-term monitoring are required for safe long-term storage of CO2. Injection wells should be plugged after the CO2 injection period, but monitoring wells need to be plugged at the end of the long-term monitoring. PISC costs are assumed to last for 30 years after the completion of the injection/production period. Benson and Cole (2008) categorized monitoring operations for two cases, basic and enhanced monitoring programs with additional operations. Cost model for these operations is designed according to the EPA (2008, 2010) baseline postinjection activities and their costs. There is some uncertainty as to how shale-gas wells would be treated according to the injection well classification system utilized by the United States. Exhausted oil and gas wells that are used for disposal of fluids are often treated as “Class II” wells. CO2 injection wells are referred to as “Class VI” wells. CO2 sequestration in class II and class VI wells have substantial differences, such as higher injection rate, higher amount of injected CO2, higher pressure, and longer time period in class VI wells EPA (2012a, 2012b). As of the time that this study was conducted, the relevant standards for Class VI wells had not yet been completed. We thus run scenarios in which the producer/injector well is treated alternately as a Class II well and a Class VI well. Our Class VI well scenarios involve a high level of PISC and monitoring activities. 6.2.3.11 Unit cost analysis The cost metric used in this analysis is the present discounted average cost of transportation, injection, and PISC per metric ton of industrial CO2 injected over the duration of the injection period—referred to herein as the “Unit Technical Cost” or UTC (Mian, 2011).

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Our UTC calculation levelizes the costs of transportation, injection, enhanced production, and postinjection site care and monitoring, as shown in Eq. (6.12): UTC5UTCTransportation 1UTCInjection 1UTCproduction 1UTCPISC Each of the elements of Eq. (6.17) is defined as: P100   Ck;t =ð11rÞt ; UTCk 5 Pt542   100 t t542 Qt =ð11rÞ

(6.17)

(6.18)

where k 5 {transportation; injection; production; PISC}; Ck,t 5 the costs of activity k incurred in year t; Qt 5 the quantity of CO2 injected in year t (in tons); and r 5 the annual discount rate, which is set to 10% in our analysis. Note the time horizon used in Eq. (6.13) corresponds to the injection period assumed in this paper. Because of the large number of input variables and uncertainty associated with the model parameters, a scenario analysis approach has been applied to illustrate the sensitivity of UTC to model variables and parameters. Six different types of scenarios are developed as illustrative examples (Tables 6.6 and 6.7): 1. 2. 3. 4. 5. 6.

Sensitivity of subsurface conditions (Scenarios S1, S2, S3, and S4): Sensitivity of emitter size (Scenarios S5 and S6) Gas prices (Scenario S7) Sensitivity of pore space acquisition cost (Scenarios S8 and S9) Straight-line transport distance (Scenarios S10 and S11) Long-term site care (Scenario S12)

The subsurface scenarios deserve special comment. We define two different spacings between the producer and injector wells (900 and 1400 ft.) and two different constant bottomhole pressures (1680 and 3360 psi). We acknowledge that other subsurface variables, such as permeability, are certainly important determinants of injectivity and will thus influence cost. While the SRM can consider different formation geologic conditions, we focus on well spacing and bottomhole pressure in order to maintain consistency with Kalantari (2013), from which we draw our SRM. Scenario S12 also deserves some comment. In this scenario the CO2 injection well is assumed to be categorized as a Class VI well. This assumption will increase the postinjection activities and corresponding costs. The manner in which postinjection activities affect costs under a Class VI well assumption depends not only on the scope of long-term monitoring activities required but also on the manner of financing the Class VI requirements. We assess two such scenarios here. The first Class VI well scenario involves postponing expenditures until the time for postinjection site care arrives. This scenario is equivalent to requiring site operators to establish an escrow fund beginning at the start of the production phase whose future value is equivalent to the costs of postinjection site care. The second Class VI well scenario involves requiring site operators to establish an escrow fund at the beginning of the production phase whose present value is equal to the future value of the costs of postinjection site care. These cases are meant to serve as boundary cases—the prevailing mechanism for financing postinjection site care costs for Class VI will depend on decisions made by future Class VI well operators.

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TABLE 6.6 Detailed assumptions for scenario simulation. Gas price (low, medium, high)

Pore space acquisition

Straight-line transport distance

Long-term site care

Subsurface conditions

Size of emitter

S1

Medium distance/high bottomhole pressure

Medium (100,000 Triangular metric ton/y) distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

S2

Medium distance/low bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

S3

Low distance/high bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

S4

Low distance/low bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

S5

Low distance/ high bottomhole pressure

Low (30,000 metric ton/y)

Triangular Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

S6

Low distance/high bottomhole pressure

High (500,000 metric ton/y)

Triangular Distribution ($2, $4, $6) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

S7

LOW DISTANCE/ HIGH

Medium (100,000 Triangular metric ton/y) Distribution (2, 8, 16) $/Mscf

33 $/acre

Medium (50 mile)

Class II well

bottomhole pressure S8

Low distance/ high bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

2 $/acre

Medium (50 mile)

Class II well

S9

Low distance/high bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

65 $/acre

Medium (50 mile)

Class II well

S10 Low distance/ high bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (20 mile)

Class II well

S11 Low distance/high bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (100 mile)

Class II well

S12 Low distance/ high bottomhole pressure

Medium (100,000 Triangular metric ton/y) Distribution (2, 4, 6) $/Mscf

33 $/acre

Medium (50 mile)

Class VI well

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TABLE 6.7 Categorization of simulation scenarios by sensitivity type.

Figs. 6.20 and 6.21 provide an overview of the technoeconomic results for each of the aforementioned scenarios. For reference, Scenario S3 is considered a “base case” scenario describing emitter size, subsurface conditions and other geospatial and economic variables. Fig. 6.19 shows the mean over 1000 UTC simulations, plus and minus one standard deviation, for each of the 12 scenarios.

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FIGURE 6.20 Summary of technoeconomic analysis scenarios: points indicate the mean UTC for each scenario, while the whiskers indicate 6 1 standard deviation. PISC, postinjection site care and monitoring.

The analysis suggests that the UTC for industrial CO2 transportation and sequestration is most sensitive to the subsurface conditions, emitter size, and the distance over which the CO2 must be transported. Referencing Scenario S6 in particular, we note that larger emitter sizes are associated with a lower per-unit CO2 transportation and storage cost, a result of economies of scale in pipeline transportation and injection costs. Results from Scenario S7, which models the impact of high and volatile future natural gas prices, suggest that revenues from selling CH4 during the injection phase (essentially enhanced gas recovery) can substantially offset the costs of CO2 transportation and storage. Our analysis should not, however, be taken to suggest that enhanced gas recovery via CO2 flooding is economical for its own sake. Whether the long-term storage of CO2 in shales is ultimately regulated as a Class II or Class VI activity under the UIC requirements does not appear to substantially affect the economics of industrial CO2 storage (Scenario S12) in the first financing scenario. In the second financing scenario, the requirements to post funds equivalent (in present value terms) to the future value of site care costs increases the unit

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FIGURE 6.21 Contribution of cost components to the total unit technical cost.

technical cost of CO2 storage in shale formations by $20
$36 per ton of CO2. Here we emphasize that both our estimates of the costs for long-term site monitoring and care, and the mechanism for financing under the Class VI regime are uncertain, since guidance on Class VI wells is relatively new and may evolve in the future. Fig. 6.21 shows the contribution of transportation, injection, postinjection site care and monitoring, and pore space acquisition cost to the overall UTC for each scenario, evaluated at the mean simulated UTC (from Fig. 6.20). With the exception of Scenario S2, which represents a high-pressure reservoir with a moderate distance between producer and injector wells, transportation of CO2 from the industrial source to the sink is the dominant contributor to overall UTC. Pore space acquisition and postinjection site care do not contribute substantially to overall economics, regardless of scenario. Not shown in Fig. 6.21 is CO2 separation, which also does not contribute substantially to overall economics. 6.2.3.12 Discussion The analysis of the subsurface scenarios suggests that in most cases (except Scenario S2) the average overall UTC of transportation, injection, and long-term site activities is between $60 and $88 per metric ton of CO2. In Scenario S3 (Low Distance/High Bottomhole Pressure), as base case, UTC of injection cost can be as low as $22.40 per metric ton of stored CO2. The greater bottomhole pressure corresponds to more storage

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potential; that is, increased CO2 storage capacity per area of land (or per volume of subsurface formation) due to high injection pressure. Shorter transport distances are the most powerful way to lower the UTC of industrial carbon sequestration in the Marcellus shale. Both of these factors will tend to dominate any increased separation costs associated with CO2 breakthrough. We also find that the UTC is highly sensitive to emitter size. Larger emitter sizes are associated with a lower per-unit CO2 transportation and storage cost. Overall UTC could be as low as $31 per metric ton of stored CO2 for a large emitter (500,000 metric ton/year of CO2 emission rate) and could be as high as $152 per metric ton of stored CO2 for a small emitter (30,000 metric ton/year of CO2 emission rate). The overall UTC is highly sensitive to the transportation distance and could be $39 per metric ton for a straight-line distance of 20 miles from emitter to well and could be as high as $100 per metric ton of stored CO2 for 100 miles from emitter to well. The overall UTC is not sensitive to whether the long-term storage of CO2 in shale is ultimately regulated as a Class II or Class VI well under the underground injection control (UIC) requirements. While capture costs were not explicitly part of our problem boundary, they will vary by source type and capture technology, as summarized in Table 6.8. Table 6.8, which summarizes the results of previous literature on geologic CO2 sequestration, puts our results in some perspective. We emphasize that this work is exploratory in nature and is intended to serve as a starting point in understanding the performance of a process that is not yet well-understood. The methods developed in the present analysis have value for future work in this area and have already highlighted the important role that subsurface characterization plays in influencing sequestration costs. Results from our exploratory analysis generally arrive at costs that are larger than those reported in the previous literature, although our estimates are in line with those of Smith et al. (2001) for saline formations. In particular, our estimates of CO2 transportation cost via pipeline are generally larger than what has been reported in the literature. This may be primarily because of the nature of our case study—our focus on industrial emitters implies lower transported volumes of CO2 and thus higher costs (due to economies of scale in transportation). Other studies, however, have typically focused on volumes similar to what would be produced from a single power plant or portfolio of power plants. As Fig. 6.21 suggests for Scenario S6, however, the transportation costs for a large industrial emitter would not be substantially higher than those transportation costs reported in the existing literature (assuming a short transportation distance and high bottomhole pressure). Based on analysis of a single injector/producer well pairing, the estimates for the cost of CO2 storage are in line with the higher end of the range of prior estimates for geologic CO2 sequestration in other types of formations. It is found that the cost structure is dominated by transportation and injection costs. Pore space acquisition and postinjection site care are minor contributors to overall costs.

6.3 Advances in sensory technologies The use of pipeline is considered as a major means of conveying petroleum products such as fossil fuels, gases, chemicals, and other essential hydrocarbon fluids that serve as assets to the economy of the nation. It has been shown that oil and gas pipeline networks

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TABLE 6.8 Comparison of results with prior research. Source

Cost item

Cost ($/metric ton)

Description

Tayari et al. (2015)

Sequestration

22.4

UTC of injection for Scenario S3 (low distance between wells/high bottomhole pressure)

Tayari et al. (2015)

Sequestration

36.1

UTC of injection for Scenario S1 (medium distance between wells/high bottomhole pressure)

Tayari et al. (2015)

Transportation

38.8

UTC of transportation for Scenario S3(medium emitter, 100,000 metric ton/year of CO2 emission rate) and straight line distance of 80 km

Tayari et al. (2015)

Transportation

8.5

UTC of transportation for Scenario S6 (large emitter, 500,000 metric ton/year of CO2 emission rate) and straight line distance of 80 km

NETL (2014c)

Sequestration

5.4
49.8

For deep saline aquifer. Mount Simon in Illinois from 5.4 to 7.8 and Rose Run formation in central Pennsylvania from 22.6 to 49.8 $ per metric ton

NETL (2010a)

Sequestration

5.5
11

For deep saline formations. It can be as high as $25.4 per metric ton

Eccles et al. (2009)

Sequestration

2.4
8.4

For sandstone saline reservoirs at depth of 1600 m

Rubin (2005)

Sequestration

5

For geologic storage

Bachu (2008)

Sequestration

0.5
5.0

For onshore operations

Bachu (2008)

Sequestration

6
12

For offshore operations

Smith et al. (2001)

Sequestration and transportation

40
77

For saline formations

Rubin (2005)

Transportation

3.2

For 160-km pipeline

Ogden (2002)

Transportation

3.45
5.26

For 100-km pipeline

Holloway (2008)

Transportation

7.82

For 500-km pipeline

Heddle et al. (2003)

Transportation

1.50
2

For 100-km pipeline for a IGCC power plant with 2.16 metric ton per year emission rate

are the most economical and safest mean of transporting crude oils and they fulfill a high demand for efficiency and reliability. For example, the estimated deaths due to accidents per ton-mile of shipped petroleum products are 87%, 4%, and 2.7% higher using truck, ship, and rail, respectively, compared to using pipelines (Adegboye et al., 2019). Timely pipeline leak detection is a significant business issue in view of a long history of catastrophic incidents and growing intolerance for such events. It is vital to flag containment loss and location quickly, credibly, and reliably, for all green- and brownfield critical lines in order to shut down the line safely and isolate the leak. Pipelines are designed to transport hydrocarbons safely; however, leaks have severe safety, economic, environmental,

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and reputational effects. Important measures are implemented through real-time instrumentation, telecommunications, SCADA, DCS, and associated online leak detection applications. The major tasks for pipeline operation include leak detection for pipelines conveying various flowing fluids—gas, liquid, and multiphase flow. As transporting hazardous substances using mile-long pipelines has become popular around the globe in recent decades, the chance of the critical accidents due to pipeline failures has increased (Jia et al., 2019). Previous work involved fiber Bragg grating (FBG) hoop strain sensors, which are among the most recently reported technologies aimed at accomplishing the goal of continuous pipeline monitoring. Multiple hoop strain signals can be extracted from distributed FBG hoop strain sensors set along the pipeline to reflect leakage process. Jia et al. (2019) demonstrated the use of multiple, distributed FBG hoop strain sensors in cooperation with a support vector regression (SVR) to localize a leakage point along a model pipeline. A series of terminal hoop strain variations were extracted as the input variables to achieve multiregression analysis as to localize the leakage point. The parameters of different kernel functions are optimized through fivefold cross validation to obtain the highest leakage localization accuracy. The result shows that when taking radial basis kernel function (RBF) with optimized C and γ values, the localization mean square error (MSE) reaches as low as 0.043. The antinoise capability of the SVR model is evaluated through superimposing Gaussian white noise of different levels. From the simulation study, the average localization error is still acceptable (  500 m) even in 5% noise situation. The influence of hoop strain sensing points as input variables is also investigated. The system with more hoop strain sensing points shows more stable capability for different level noises. Their results demonstrate the feasibility and robustness of the SVR approach using multihoop strain measurements for pipeline leakage localization. The causes of the failures are either intentional (like vandalism) or unintentional (like device/material failure and corrosion) damage, leading to pipeline failure, and thus resulting in irreversible damage which includes financial losses and extreme environmental pollution, particularly when the leakage is not detected in a timely way (Arifin et al., 2018). Arifin et al. (2018) introduced a novel data-driven leak detection and localization algorithm based on the Kantorovich distance concept. Mass flow rates and pressure measurements are used to identify possible change in the pipeline status. Based on the pipeline leak signature, a leak is detected and the location is further inferred. Their method was applied successfully to a simulated pipeline in a transient condition. The efficacy of the proposed method was also proven by applying it to an industrial pipeline network with controlled leak tests in real time. The method successfully detected both small (as small as 1% of the nominal flow rate) and large test leaks in the realistic pipeline. The time required to detect and localize a leak with the proposed algorithm was much lower than the available commercial leak detection system. The accuracy of the proposed leak localization method was demonstrated to be better, especially for the small leaks. Fig. 6.22 shows different classes of leak detection systems illustratively. There is also a third class called the nontechnical methods, which refer to visual inspection, smelling the tracer element, sensing special sound, and the soap bubble screening method (Murvay and Silea, 2012). These methods include trained personnel or a specially trained dog along with its trainer, to walk along the pipeline or inspection of the pipeline from a manned or unmanned aircraft for visual or other evidence of leaks. The downside of these methods is

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FIGURE 6.22 Classification of leak detection systems.

that detection depends upon the frequency of the inspection. The accuracy of the method is also dependent on the experience and skill of the inspector. Finally, buried pipelines are not accessible for visual inspection. External or hardware-based methods work on the principle of physical detection of escaping fluid using local sensors. External methods can usually detect the leak location more precisely but they are more costly and cannot easily and economically be retrofitted in existing buried pipelines, in most cases (Geiger, 2006). Moreover, the testing cycle of external methods is longer than that of software-based methods (Zhang et al., 2015). Due to the complexity to apply and high cost, the external methods are not generally used for continuous monitoring of leaks on long pipelines. One of the popular classes of external leak detection system is the acoustic emission detector type method (Watanabe et al., 1993) and its variants. The basic idea is that the leaked fluid leaves behind an acoustic signal while product passes through a leaking hole of the pipe. Acoustic sensors, placed at the two ends of the pipeline, detect this acoustic signal and the leak is localized based on the time difference required to reach the signal at the two ends of the pipeline. However, though these methods are gaining much attention in recent years for leak localization, they often suffer from inaccuracy due to the presence of other sources of extraneous noise such as a pump (Murvay and Silea, 2012). The accuracy is also dependent on the range of detection and frequency of the acoustic sensors. The fiber optic sensing cable method is one of the most sensitive hardware-based methods. In this method a fiber optic cable is installed along the entire length of the buried pipeline. The cable is initially at the same temperature as ground. When the leaked fluid comes into contact, the temperature of the cable changes in the leakage position (Geiger, 2006). Depending upon the active or passive mode, this change in temperature is detected

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either by sensing significant absorption or scattering of the emitted radiation by the leaked fluid molecule (active) or utilizing a thermal imaging technique (passive) (Murvay and Silea, 2012). Thus the leak is detected and localized. However, this method is very costly (Murvay and Silea, 2012) and works only for pipelines which carry products which are either warmer or colder than ground temperature (Geiger, 2006). Otherwise a temperature change due to a leak cannot be traced. Other sensing cable methods such as the electrical, liquid, or vapor sensing cables are also based on burying an auxiliary sensing cable along the full length of the main pipeline. In the case of the electrical cable, the materials are chosen such that some of its electrical properties (resistance, capacitance, etc.) will change when it comes into contact with the fluid passing through the main pipeline. Similarly, the liquid or vapor sensing cables are permeable to the fluid passing through the main pipe (Geiger, 2006). The average economic loss due to incidents of pipeline leakages is enormous. Over the past three decades, pipeline accidents in the United States have damaged property which cost nearly $7 billion, killed over 500 people, and injured thousands. For example, the incident of pipeline explosion in the community of San Bruno, California, USA on September 6, 2010 killed eight people, and injured more than 50 (Lena, 2012). In a similar incident of a pipeline defect that occurred in Michigan, USA on July 26, 2010, more than 840,000 gallons of crude oil spilled into Kalamazoo River with an estimated cost of $800 million. The risks inherent in transporting fuel through pipelines are analogous to the risks inherent in traveling by airplane. Airplanes are safer than cars, which kill about 70 times as many people a year (highway accidents killed about 33,000 people in 2010, while aviation accidents killed 472). But when an airplane crashes, it is much more deadly than any single car accident, demands much more attention, and initiates large investigations to determine precisely what went wrong. The same holds true for pipelines. Based on fatality statistics from 2005 through 2009, oil pipelines are roughly 70 times safer than trucks, which killed four times as many people during those years, despite transporting only a tiny fraction of fuel shipments. But when a pipeline does fail, the consequences can be catastrophic (though typically less so than airplane accidents), with the very deadliest accidents garnering media attention and sometimes leading to a federal investigation (Lena, 2012). The causes of pipeline damage vary. Fig. 6.23 shows a pie chart that illustrates the statistics of the major causes of pipelines failure, which include pipeline corrosion, human negligence, defects during the process of installation and erection work, flaws occurring during the manufacturing process, and external factors (Bolotina et al., 2018). Several pipeline leak detection methods have been proposed during the last decades using different working principles and approaches. Existing leakage detection methods are (Adegboye, et al., 2019): • • • • • •

acoustic emission; fiber optic sensor; ground penetration radar; negative pressure wave; pressure point analysis; dynamic modeling;

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FIGURE 6.23 A pie chart of the statistics of the sources of pipeline failure. Source: Data from Bolotina et al. (2018).

• vapor sampling, infrared thermography; and • digital signal processing and mass-volume balance. These methods have been classified using various frameworks. Some authors have classified them into two categories: hardware- and software-based methods (Murvay and Silea, 2012). As knowing about the existence of a leak is not always enough to launch a corrective action, some of the leak detection techniques are designed to allow the possibility of locating the leak. Murvay and Silea (2012) identified the state-of-the-art in leak detection and localization methods. Additionally, they evaluated the capabilities of these techniques in order to identify the advantages and disadvantages of using each leak detection solution. They distinguish three categories: Automated detection—complete monitoring systems that, can report the detection of a gas leak without the need of a human operator, once they are installed (e.g., fiber optic or cable sensors). Semi-automated detection—solutions that need a certain amount of input or help in performing some tasks (e.g., statistical or digital signal processing methods) Manual detection—systems and devices that can only be directly operated by a person (e.g., thermal imagers or LIDAR devices). Most detection techniques rely on the measurement of a certain physical quantity or the manifestation of a certain physical phenomenon. This can be used as a rule for classification as we have several commonly used physical parameters and phenomena: acoustics, flow rate, pressure, gas sampling, optics, and sometimes a mixture of these. An example is available in relation to the optical detection methods. Because of the great variety of these detection solutions, leak finding technologies are sometimes classified into optical and nonoptical methods (Batzias et al., 2011). Some authors see the technology as fitting into two great categories: direct, and indirect or inferential methods (Folga, 2007). The direct detection is made by patrolling along the pipelines using either visual inspection or handheld devices for measuring gas emanations.

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Thanks to the technological advancements it is now common to use helicopter- or airplanemounted optical imaging devices, especially for very long pipelines. Indirect or inferential methods detect leaks by measuring the change of certain pipe parameters such as flow rate and pressure. The most common way of classifying leak detection methods is based on their technical nature (Scott and Barrufet, 2003). Thus one can distinguish two main categories of methods: hardware-based methods and software-based methods. These two categories are sometimes mentioned as externally or internally based leak detection systems. Although not often presented in recent literature as a separate category, there is a third class that covers the so-called biological methods. We will refer to these methods as nontechnical. Fig. 6.24 illustrates these main categories and the different methods associated with each of them. This classification is similar to the one presented in the previous paragraph with the remark that indirect or inferential methods overlap with the softwarebased methods while the direct methods cover both hardware methods and nontechnical methods. Nontechnical leak detection methods are the ones that do not make use of any device and rely only on the natural senses (i.e., hearing, smelling, and seeing) of humans and/or animals. Hardware-based methods rely mainly on the usage of special sensing devices in the detection of gas leaks. Depending on the type of sensors and equipment used for detection, these hardware methods can be further classified as: acoustic, optical, cable sensor, soil monitoring, ultrasonic flow meters, and vapor sampling. Software-based methods, as the name states, have software programs at their core. The implemented algorithms continuously monitor the state of pressure, temperature, flow rate, or other pipeline parameters and can infer, based on the evolution of these quantities, if a leak has occurred. The software methods can use different approaches to detect leaks: mass/volume balance, real-time transient modeling, acoustic/negative pressure wave, pressure point analysis, statistics, or digital signal processing. Adegboye et al. (2019) classified different methods into the following categories: • exterior;

FIGURE 6.24

Classification of gas leak detection techniques based on their technical nature (Murvay and

Silea, 2012)

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• visual or biological; and • interior or computational methods. This classification is shown in Fig. 6.25. The exterior approach utilizes various man-made sensing systems to achieve the detection task outside pipelines. Moreover, the biological approach utilizes visual, auditory, and/or olfactory senses of trained dogs or experienced personnel to detect leakages. In addition, the interior approach consists of software-based

FIGURE 6.25 Flow chart of different pipeline leakage detection approaches.

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methods that make use of smart computational algorithms with the help of sensors monitoring the internal pipeline environment for detection task. Remote monitoring can be achieved by carrying camera or sensing systems to designated locations by smart pigging, helicopters or autonomous underwater vehicles (AUVs)/drones, or using sensor networks.

6.3.1 Exterior-based leak detection methods Exterior methods mainly involve the use of specific sensing devices to monitor the external part of the pipelines. These methods can be used to determine abnormalities in the pipeline surroundings and also detect the occurrence of leakages. Irrespective of the working principles these sensing methods are based on, they require some form of physical contact between the sensor probes and the infrastructure under monitoring. Examples of these devices include acoustic sensing, fiber optic sensing, vapor sampling, infrared thermography, and ground penetration radar. The operational principle, strengths, and weaknesses of these methods are discussed in the subsequent sections. 6.3.1.1 Acoustic emission sensors Acoustic emission, according to American Society of Mechanical Engineering (ASME) 316 standard (Prakash et al., 2020), is defined as “the class of phenomena whereby transient elastic waves are generated by the rapid release of energy from localized sources within a material, or the transient waves so generated.” Acoustic emission employs noise or vibration generated as a result of a sudden drop in pressure to detect the occurrence of pipeline leakage. Fig. 6.26 shows a typical setup of acoustic emission testing. The test object is loaded under a controlled load. A sensor to sense any emitted acoustic emission is kept in contact with the test object. The load/stress applied on the test object causes the defects such as crack growth and plastic deformation. This sudden movement at the source produces a stress wave, which radiates out of into the structure and excites a sensitive piezoelectric transducer. When a pipeline leak occurs, it generates elastic waves in the frequency range up to 1 MHz (Martini et al., 2017). Martini et al. (2017) developed a technique involving early detection of leaks occurring in small-diameter customers’ connections to water supply networks. An experimental campaign was carried out in a test bed to investigate the sensitivity of acoustic emission (AE) monitoring to water leaks. Damage was artificially induced on a polyethylene pipe (length 28 m, outer diameter 32 mm) at different FIGURE 6.26 Basic schematic of the acoustic emission method.

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distances from an AE transducer. Measurements were performed in both unburied and buried pipe conditions. The analysis permitted the identification of a clear correlation between three monitored parameters (namely total hits, cumulative counts, and cumulative amplitude) and the characteristics of the examined leaks. The test bed, sketched in Fig. 6.27, simulated a section of the water supply network. A polyvinyl chloride (PVC) pipe with an outer diameter of 90 mm (DN 90) was used as the water main. A highdensity polyethylene (HDPE) pipe of length 28 m and smaller diameter (DN 32) was connected to the larger one as the customers’ service pipe. It was placed at a depth of about 0.5 m on a layer of backfill soil, but left unburied. Two-way shut-off valves were installed at both its extremities. A pressure tank, equipped with a pressure gauge and a pressure regulation system, fed the facility at a constant pressure of about 3.5 bar, which replicates the typical network operation. The percentage variation of the parameters in the leaking conditions, with respect to the nonleaking state, was computed to better compare their sensitivity to leaks (Fig. 6.27). The values related to the cumulative counts are the highest for all the leaking conditions, and in particular for the most distant leak (Lk-3). Hence, the cumulative counts seem potentially more suitable to assess the presence of active leaks. The distribution of the AF over the RA values is also computed for all the tested conditions. Fig. 6.28 reports the comparison between conditions NL and Lk-3, shown as an example. Apparently, the leaking condition exhibits a larger percentage of tensile-type AE events; that is, it is characterized by higher values of the AF to RA ratio (as opposed to shear-type AE events, which feature lower ratios) (Fig. 6.29). Hence, these preliminary tests showed that both the monitoring of cumulative counts and the analysis of the AF versus RA pattern may be suitable for detecting leaks by means of AE measurements. Nonetheless, further data and analyses are required to confirm the effectiveness and the convenience of these tools for leak detection purposes, as well as to achieve a satisfactory degree of confidence in the detection, in particular, for distant leaks. The tests provided moderately satisfactory results. The AE technique showed an acceptable sensitivity to the presence of active leaks in the unburied pipe. The trend of at least one AE parameter, namely the cumulative counts parameter, exhibited a direct correlation with both the leak distance and the leaking flow rate. A series of tests in a buried pipeline was also conducted. Tests performed on the buried pipe confirmed the possibility of detecting leaks within a range of 8 m, which is basically sufficient for the application of interest. However, leak detection could not be achieved with a satisfactory reliability. In particular, the experiments showed that the pipe material and the presence of soil as a

FIGURE 6.27

Schematics and characteristics of the test bed with unburied pipe. PVC, polyvinyl chloride; HDPE, high-density polyethylene; DN, outer diameter.

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Percentage variation of AE parameters: (A) total hits; (B) cumulative counts; (C) cumulative

amplitude.

FIGURE 6.29 Diagram of AF versus RA, comparison between conditions NL and Lk-3.

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surrounding medium caused a significant attenuation of the AE signal, which hampered the detection even for leaks that were rather close to the sensor location. It is worth noting that the investigation of more advanced signal processing methods (e.g., analysis of the AE waveforms in the frequency domain or even pattern recognition techniques) may be worthy of interest to possibly enhance the results. Acoustic methods for leak detection can be divided into two classes: active and passive. Active methods detect pipeline defects by listening to the reflected echoes of sound pulses emitted due to leakage. On the contrary, passive methods detect defects by listening to changes in sound generated by pressure waves in the pipelines. There are three major categories of acoustic sensors, namely aquaphones, geophones, and acoustic correlation techniques. Aquaphones require direct contact with hydrants and/or valves, while geophones listen to leaks on the surface directly above the pipeline. At the same time, steel rods can also be inserted into the buried pipe to transmit signals to mounted sensors on the rods. The amplitude of the measured pressure signal is measured as sound pressure level (SPL) (Naranjo and Baliga, 2009):  p (6.19) SPL 5 20 log p0 where p0 is the pressure amplitude of a reference sound, taken to be 20 μPa, considered the threshold of human hearing. Thus, at p 5 p0, the scale is assigned a sound pressure level of 0 dB. One important characteristic of sound is that the speed of propagation depends on density and pressure. As a result, the velocity of sound varies with the medium. Such a phenomenon has important implications for ultrasound as a means for detecting leaks. As shown in the expression next, the wavelength λ of a wave propagating in an isotropic medium is directly proportional to the velocity of the wave (c) and inversely proportional to its frequency (v) (Fig. 6.30). λ 5 c=v

(6.20)

Thus, the wavelength of sound decreases as frequency increases into the ultrasound region. For example, assuming a velocity of sound in dry air of 331 m/s, a wavelength in a midultrasound, say between 25 and 70 kHz, can range between 5 and 13 mm. Ultrasound generates high-energy, shortwave signals that are directional and localized. As Fig. 6.31 shows, a gas leak generates sound through a wide range of the frequency spectrum. Also ultrasound is related to the power level of the source with the following relationship:  W (6.21) SPL ~ 10 log 10212 As SPL is directly proportional to the gas generated power due to expansion it can also be expressed as:  RT _ m (6.22) SPL ~ log M _ is the mass flow rate of the jetting gas, T is gas temperature at the orifice, M is where m the molecular weight, and R is the gas constant. It is this relationship between mass flow

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FIGURE 6.30 Noise spectrum showing audible and ultrasonic ranges. At a span of 25
75 kHz, the ultrasonic gas leak detection range is a small portion of the range of ultrasound.

FIGURE 6.31 Noise spectrum of nitrogen gas leak in the 20
60 kHz frequency band (d 5 1 mm; p 5 2758 kPa).

rate and SPL that airborne ultrasound detectors employ in order to detect leaks. The turbulent flow of the gas in air produces heat and sound energy as the gas molecules collide. And although heat dissipates quickly, the sound energy is transmitted at considerable distances, allowing the detectors to respond to changes in the sound pressure level. Ultrasonic gas leak detectors measure the airborne ultrasound generated by escaping gas. The amplitude of this sound, expressed in decibels, provides a measure of the leak

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rate produced by the gas. The relationship between the leak rate, the physical configuration of the leak, and the thermodynamic properties of the gas are well understood. These are derived from assumptions of ideal gas behavior and fixed-geometry choked (sonic) orifice flow. The mass rate that assumes choked flow at the leak source is given by the following isentropic flow relation: sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi   γ11 γM 2 γ21 _ max 5 pA (6.23) m RT γ11 where mmax represents the maximum mass flow rate of gas exiting from the pressurized vessel through the leak orifice; A is the area of the orifice; T and p represent the stagnation temperature and pressure within the vessel upstream of the leak orifice, respectively; and γ 5 cp/cv is the ratio of specific heats for the gas. One important result from the derivation of the equation above is the critical pressure ratio. In order for the mass rate to reach a maximum, the ratio of ambient pressure to the pressure inside the pipe or vessel must be:  γ  po 2 γ21 5 (6.24) γ11 pi critical For methane (γ 5 1.32), this critical pressure ratio is 0.54. As a result, for ambient atmospheric pressure, an internal pressure of only 186 kPa (27 psi) is sufficient to produce the characteristic choked flow that generates ultrasound. (In practice, however, larger pressures are required to generate an ultrasonic signal greater than ambient ultrasonic background noise.) For the case of small size orifices—on the micrometer range—assumptions of ideal gas may not apply, as it is unclear whether flow through the orifices is in the continuous regime. So while isentropic flow is assumed in the derivation of Eq. (6.5), a discharge coefficient Cd is required to account for dissipative effects. This coefficient can be defined as sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi   γ11 γM 2 γ21 _ 5 Cd pA m (6.25) RT γ11 where R is the gas constant, T is the gas temperature at the orifice, M is the molecular weight, and m_ represents jetting gas mass flow rate. Both aquaphones and geophones can be used to detect and locate leakages. However, these approaches are not effective due to their slow operating procedures. The acoustic correlation method is more sophisticated than the abovementioned methods. In this approach, two sensors are required to be positioned on either side of the pipe to detect leakage. The time lag between the acoustic signals when the sensors sense a leak is used to detect and identify the point of leakage (Fuchs and Riehle, 1991). One of the most effective ways to detect leaks is to use acoustic analysis. However, the majority of leak detection technology is based on analyzing the acoustic signal collected by acoustic sensors installed on the wall of pipelines. Studies indicate that the location of the pipeline leak point can be found out by placing the hydrophone on the pipeline and collecting the sound signal of the pipe and analyzing it (Khalifah et al., 2011). Wang et al. (2017a,b) used time-domain statistical features from acoustic sensors outside of the pipeline to recognize the leakage. These methods will

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greatly reduce the detection efficiency, and will increase the workload and complexity of the detection, and the maintenance of the equipment will be extremely inconvenient. Furthermore, it may not be able to localize a tiny leak in a high accuracy. Some in-pipe acoustic technology, that is, the SmartBall, is also capable of detecting small leakages in long and buried water pipelines (Fletcher and Chandrasekaran, 2008). However, it is hard to interpret underwater measured acoustic signal events due to variations of the surroundings parameters, signal similarities, and the stochastic nature of events. A reference standard for setting up and evaluating acoustic emission sensors deployed for pipeline leakage detection was proposed by Miller et al. (1999). They developed a reference standard for setting up and evaluating acoustic emission equipment to be used in pipeline leak detection. The reference standard comprises a short length of 2-inch diameter piping with facilities for introducing several kinds of controlled leaks. The reference standard proved very valuable not only for checking out equipment, but also for characterizing source mechanisms as part of an integrated approach to quantitative acoustic emission leak detection/location technology. The effects of pressure and air injection were measured for thread leaks on the order of 0.1 gal/h, a leakage rate that is important in the context of environmental protection regulations. Taking this knowledge to the field, a thread leak of only 0.014 gal/h was successfully detected and located by injecting nitrogen into the line at 25 psi. This leak was located with 1-foot accuracy, using two different location techniques and 25-foot sensor spacing. Experimental investigation of pipeline leakage subjected to socket joint failure using acoustic emission and pattern recognition was proposed by Li et al. (2018). The acoustic characteristics of leak signals in the socket and spigot pipe segments were investigated. The study showed that dominant frequency of environmental noise is less than 2 kHz while the dominant frequency of the acoustic signals due to the failure of the socket joint is concentrated in the 0
10 kHz range. The feature set obtained was trained with an artificial neural network (ANN), and good estimation accuracy of 97.2% and 96.9% was achieved. This indicates that acoustic emission-based methods can exhibit high sensitivity over long distances. However, additional strategies to increase the leak noise (such as pipeline pressure amplification) may be required. Ai et al. (2006) introduced a combination of a linear prediction cepstrum coefficient (LPCC) and a hidden Markov model (HMM) to examine the damaged acoustic signals. They designed the pipeline prevention monitoring and leak detecting system based on calculating LPCC and using HMM to recognize damage acoustic signals. The continuous nonsteady time-variety process was subframed and described with a series of short steady sequences on the basis of acoustic signal characteristic analysis. LPCC which represents accurately each short-time acoustic signal was selected as the acoustic signal characteristic parameter and extracted effectively using the Durbin algorithm; HMM was established to recognize damage types by the Baum-Welch revaluation algorithm with the state-transfer probability and observing time sequences characteristic parameters; using Viterbi decoding algorithm realized the search of the best transfer route and achieved the corresponding export probability. The results show that the acoustic singles recognition rate is improved effectively based on the sound spectrum by LPCC and HMM, and can be up to 97%. HMM was used to identify corrupted signals while LPCC, which represents short-time acoustic signals, was adopted as the characteristic signal parameter.

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Jia et al. (2018) conducted a gas leakage detection experiment on a gas pipeline length of 3.13 km using measured acoustic waves with the sensors positioned at different locations along the gas pipeline. In their previous work, a fiber Bragg grating (FBG) hoop strain sensor with enhanced sensitivity was developed to measure the pressure drop induced by pipeline leakage. Some hoop strain information during the leakage transient process can be extracted from the amount of FBG hoop strain sensors set along the pipeline. In this paper, an integrated approach of a backpropagation (BP) neural network and hoop strain measurement is first proposed to locate the leak points of the pipeline. Five hoop strain variations are employed as input neurons to achieve pattern recognition so as to predict the leakage point. The RMS error can be as low as 1.01% when choosing appropriate hidden layer neurons. Furthermore, the influence of noise on the network’s performance is investigated through superimposing Gaussian noise with a different level. The results demonstrate the feasibility and robustness of the neural network for pipeline leakage localization. The effect of background noise can easily mask the actual sound of a leak, thus obscuring the real signals. In order to overcome this challenge, several signal analysis techniques have been proposed in literature, such as interrogation methods (Meng et al., 2011). Meng et al. (2011) introduced a new technique involving filtering signals with wavelet transform to eliminate the background noises, and time-frequency analysis is used to analyze the characteristics of frequency domain. They concluded that most acoustic signals are concentrated in the range of 0
100 Hz. The acoustic signal recognition and extraction methods were verified and compared with others and it proves that the disturbing signals can be efficiently removed by the analysis of time and frequency domain, while the new characteristics of the accumulative value difference, mean value difference, and peak value difference of signals in adjacent intervals can detect the leak effectively and decrease the false alarm rate significantly. The formula for leak location was modified with consideration of the influences of temperature and pressure. The positioning accuracy can be significantly improved with relative error between 0.01% and 1.37%. The cross-correlation is a technique of nondestructive testing methods NDT, widely used to detect leaks from buried pipes in industrial and household facilities. This technique can be profitable when the anomaly signal has high power signal to noise ratio. Chen et al. (2012) introduced a method to extract feature weak leakage signal from signal with much noise based on wavelet entropy. Not only could the signal-to-noise ratio be increased and the feature was clearer, but also it is not sensitive to the form of signals. The nonlinear adaptive filtering was realized to weak signals according to the different characteristics between the useful signal and noise. Additionally, using wavelet packet elaborate frequency division the signal frequency bandwidth could be decomposed more subtly. The feature vectors of pipeline leakage and normal operation states could be formed based on frequency segment power, which could be used as input samples of a neural network to improve detection accuracy of pipeline leakage. The experimental results showed the small leakage would be distinguished and located effectively. Elandalibe et al. (2015) used this technique to detect several leaks at the same time, by measuring two vibration signals provided from two detectors placed at the ends of the buried pipe, and properly estimated the delay of leak-related signals. The simulation results showed it was effective in detecting the positions of several leaks (Elandalibe et al., 2015).

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Pipeline faults, such as leakage and blockage, always create problem for engineers. Acoustic reflectometry has vast applicability in fault detection, followed by the impedance method (Datta and Sarkar, 2016). The detection of an exact fault quantity and its location is necessary for the smooth functioning of plant or industry and the safety of the environment. Datta and Sarkar (2016) presented a brief discussion on various pipeline fault detection methods, that is, vibration analysis, pulse echo methodology, acoustic techniques, negative pressure wave based leak detection system, support vector machine (SVM)-based pipeline leakage detection, interferometric fiber sensor-based leak detection, filter diagonalization method (FDM), etc. They reported that these methods have been applied for specific fluids, such as, oil, gas, and water, for different layout patterns like straight and zigzag, for various lengths of pipeline like short and long and also depending on various operating conditions. Therefore, a comparison among all methods has been done based on their applicability. Among all fault detection methods, acoustic reflectometry is found to be most suitable because of its proficiency to identify blockages and leakages as small as 1% of a pipe’s diameter. Moreover this method is economical and applicable for straight, zigzag, and long or short length pipes for low, medium, and high density fluid. A detailed classification of fault detection methods for blockage and leakage is given in Fig. 6.32. 6.3.1.2 Vibration analysis Lile et al. (2012) used a vibration analysis method to describe blockage effects in a circular pipe where a fast Fourier transform (FFT) graph has been presented to describe the correlation of blockage levels to the vibration signal. In the case of fluid flow through an obstacle, the flow cross-section area reduces and as per the continuity equation the fluid velocity increases. As per Bernoulli’s principle, the pressure of the fluid then decreases. Due to this fluctuating pressure and high velocity, a prominent vibration response is observed in the pipeline. The vibration parameters are then measured using an accelerometer as shown in Fig. 6.33. The relationship between various frequency responses corresponding to different accelerometer locations (point A, B, and C) with various blockage thicknesses inside the pipe are depicted in Fig. 6.3. It is observed that frequencies at point “B” are maximum as compared to point “A” and “C,” due to the presence of a blockage at “B.” Variation of area and pressure changes the vibration pattern. After comparing the frequencies at various points of the pipe, it is observed that at the place of maximum blockage thickness, the velocity is at its maximum and the frequency varies from 7 to 9 kHz (Fig. 6.34).

6.3.2 Pulse echo methodology Pulse echo methodology is a fast and efficient way of determining the presence of a blockage inside a pipeline (Duan et al., 2014). This method is used for obtaining both the length and the equivalent cross-sectional area of a blockage, and a single microphone is used to capture the incident and reflected pulse. The power reflection ratio (i.e., ratio of square of amplitude for incident and reflected waves) and phase change of the reflected

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FIGURE 6.32 Flowchart of different fault detection methods. Pipelines

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Accelerometers mounted on pipe surface (Lile et al., 2012).

FIGURE 6.34 Frequency response at three accelerometer location (Lile et al., 2012).

signal with respect to the incident signal are combined to produce the characteristics of a blockage. Further, each pulse is allowed to filter out reflections from the pipeline ends. The following equations indicate the relationship of different parameters of wave that are propagating in a pipe that contains a blockage at a certain length of pipe (Lb), having as area ratio (σ), wave number of air (k 5 ω/c), power reflection ratio (X), where ω is radian frequency and c denotes the speed of sound. o  2 n 2 (6.26) X 5 σ2 21 = σ2 11 1 4σ2 cot2 kLb where phase difference (ψ) can be expressed as: ψ5

2σcot kLb σ2 1 1

The general solution for area ratio (σ) can be represented as: qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi     X 1 1 ψ2 1 1 6 2 X 1 1 ψ2   σ2 5 1 2 X 1 1 ψ2

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Finally the governing equation for blockage length can be expressed as (6.29):    1 21 σ2 2 1 ψ nπ ; n 5 0; 1; 2; . . . 1 Lb 5 cot k k 2σ

(6.29)

Depending on the frequency (ω 5 kc), an infinite number of solutions can be obtained for Lb. Finally, the relation between area ratio and length of the blockage can be obtained through equation 6.29 (Bhuiyan et al., 2016). 6.3.2.1 Acoustic reflectometry In acoustic reflectometry technique a pulse of sound is injected by an acoustic pulse generator into a pipeline. As a result, a reflection is produced; it passes through an amplifier, drives a loudspeaker, and travels along the length of the pipe. This pulse is measured by a microphone that is installed at the end. Wang and Economides (2009) performed this experiment in a 63-mm diameter and 16-m-long PVC pipeline that consisted of several sections, which were connected by bends. The recorded signals of 800 Hz (Fig. 6.35) were analyzed using matched filters to overcome the problem of background noise (Fig. 6.36). Matched filtering generates a series of peaks which indicates the change in cross-sectional area inside the pipeline, that is, the presence of a blockage (Fig. 6.37). An acoustic reflectometry method is also used for detecting leakage in a pipeline (Papadopoulou et al., 2008). 6.3.2.2 Transient wave blockage interaction and blockage detection Duan et al. (2014) demonstrated another method to detect blockages in pipes by observing the changes of system resonance frequencies. The analytical method is used to explain the blockage-induced frequency shifts in water pipelines. To explain the frequency shift phenomenon induced by an extended blockage, a wave perturbation analysis has been FIGURE 6.35

0.6

waves. 0.4

Amplitude (v)

0.2 0

-0.2 -0.4 -0.6

-0.8 0

5

10

15

20

25

Penetration distance (m)

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FIGURE 6.36 Matched fil-

Relative amplitude

15

tering analysis waves.

of

800 Hz

10

Pipe end 5

0 0

5

10 15 20 Penetration distance (m)

25

30

FIGURE 6.37 Presence of blockage in a pipe (Wang and Economides, 2009).

1200

Relative amplitude

1000

Blockage

800 600 400

Pipe end

200 0 0

5

10 15 20 Penetration distance (m)

25

30

conducted. Numerical and experimental tests have been carried out for the validation of analytical results which show the efficiency and accuracy of the method. 6.3.2.3 Stochastic successive linear estimator Massari et al. (2014) proposed a stochastic tool which can determine the presence of partial blockages in pipelines. Due to a partial blockage, estimation of diameter

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distribution shows unbiasness. Successive linear estimator provides the best unbiased estimation to understand the position and size of the blockage. The main advantage of the approach is its accountability of complex geometries induced by blockages, even with the existence of many structure errors of transient simulation. Apart from the abovementioned method, the impedance method is also a useful way to detect both blockages and leakages in a branched pipeline (Kim, 2014). The impedance method converts various formulated transient responses into the time domain and then calibrates different results relating to both blockage and leakage detection. The radioisotope technology (Robins, 2005) can be used to determine a blockage in pipe rapidly. For locating blockages in a pipeline, the transmission of gamma-rays is an efficient method and can enumerate the quantity of deposition in a pipe easily. The thermodynamic solid
liquid equilibrium model is another approach for calculating the precipitation of wax in an oil pipeline (Chen and Zhao, 2006). For the estimation of precipitated solid at different temperatures in a pipeline, a model has been prepared based on a theory related to molecular thermodynamics. The predicted results from the model are compared with experimental data and the results obtained are quite satisfactory. Another study was also performed to detect partial blockages in pipelines where damping of fluid transients was used (Wang et al., 2005). In this study, the magnitude of the damping rate showed the blockage size and ratios of various damping rates, and the location of the blockage inside the pipe. 6.3.2.4 Accelerometers Apart from the abovementioned studies that are totally based on acoustic emission, accelerometers are another type of vibroacoustic measuring device that are also useful for monitoring low-frequency pipe
shell vibrations (Yazdekhasti et al., 2017). They presented an approach for leak detection that involves continuous monitoring of the changes in the correlation between surface acceleration measured at discrete locations along the pipeline length. A metric called the leak detection index is formulated based on the cross-spectral density of measured pipe surface accelerations for detecting the onset and assessing the severity of leaks. The proposed noninvasive approach requires minimal human intervention and works under normal operating conditions of the pipeline system without causing any operational disturbances. The approach is demonstrated on a 76 mm diameter polyvinyl chloride pipeline test system considering varying leak severities. Aging infrastructures, specifically pipelines, that were installed decades ago and currently operating under poor conditions are highly susceptible to the threat of leaks, which pose economic, health, and environmental risks. For example, in the year 2009, the state of Ontario lost 25% of its water supply solely due to leaks. Therefore, a need arises to develop an approach that allows condition monitoring and early intervention. Several studies have been proposed for achieving leak detection and localization using accelerometers. El-Zahab et al. (2018) utilized an accelerometer-based leak detection system. A system for monitoring pressurized pipelines using vibration signals was proposed. It involves a model for a real-time monitoring system capable of identifying the existence of single event leaks in pressurized water pipelines. The model proposes that wireless accelerometers be placed within the network on the exterior of the valves connecting the pipelines. To test the viability of the proposal, experiments were performed on 1-inch cast iron

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pipelines and 1- and 2-inch PVC pipelines using single event leaks and the results were displayed. The vibration signal derived from each accelerometer was assessed and analyzed to identify the monitoring index (MI) at each sensor. The data collected from experimentation were analyzed using support vector machines (SVM), decision tree (DT), and naı¨ve Bayes (NB). A leak threshold was determined such that if the signal increased above the threshold, a leak status is identified. The developed models showed promising results with 98.25% accuracy in distinguishing between leak states and nonleak states. The proposed model aims at presenting novel approaches to providing municipalities with an affordable real-time monitoring system capable of assisting them in early detection and facilitating the repair process of leaks. In a follow-up paper, Yazdekhasti et al. (2018) presented a follow-up evaluation of the new technique in a real-size experimental looped pipeline system located in a laboratory with complexities, such as junctions, bends, and varying pipeline sizes. The results revealed the potential feasibility of the proposed technique to detect and assess the onset of single or multiple leaks in a complex system.

6.3.3 Fiber optic method This method involves installation of fiber optic sensors along the exterior of the pipeline. The sensors can be installed as a distributed or point sensor to extensively detect the variety of physical and chemical properties of hydrocarbon spillage along the pipelines. The operation principle of this method is that cable temperature will change when pipeline leakage occurs and hydrocarbon fluid engross into the coating cable. By measuring the temperature variations in fiber optic cable anomalies along the pipeline can be detected. Distributed optical fiber sensor provides environmental measurements based on three classes of scattering, namely Raman, Rayleigh, and Brillouin scattering (Tanimola and Hill, 2009). The ability to interface with existing client DCS and SCADA systems also provides automated input from fiber optic monitoring systems where product leakage requires prompt closure of pipeline valves before large spills occur. Tanimola and Hill (2009) explained the principle of leak detection and third party intruder detection using fiber optics-distributed temperature sensing (DTS) with examples of recent LNG and LPG pipeline leak detection installations, and the outcomes of fiber optic-distributed acoustic sensing (DAS) intruder monitoring case studies, with a view to improving pipeline protection and thus increase pipeline productivity and integrity, while offering protection of the environment. These classifications are based on the frequency of the optical signals, as illustrated in Figure 3.38. Brillouin scattering can measure both strain and temperature but is very sensitive to strain, while Raman scattering is only sensitive to temperature, with a greater ability to accurately measure temperature at greater or equivalent to 0.01 C resolution (Wang et al., 2017a,b). Wang et al. (2017a,b) used the location of water ingress DTS. The results showed a significant temperature change immediately after the onset of water ingress, and with data postprocessing based on temporal difference, the location information of the leak could be obtained. With a selected time window of interest, the inclination of the gas pipeline is also indicated by the differenced temperature profiles. The DTS system is still capable of identifying the position, even if the location of water ingress is changed (Fig. 6.38).

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FIGURE 6.38

Schematic representation of the electromagnetic spectrum illustrating Rayleigh, Brillouin, and Rayleigh scattering (Selker et al., 2006).

The manifestation of Brillouin scattering takes place as a result of the interaction between acoustic waves and propagated optical signals. This leads to a shift in frequency components in the received light, but in the case of the Raman scattering approach only changes in temperature only in backscattered light intensity fluctuations. Selker et al. (2006) discussed the spectrum of fiber-optic tools that may be employed to make these measurements, illuminating the potential and limitations of these methods in hydrologic science. There are trade-offs between precision in temperature, temporal resolution, and spatial resolution, following the square root of the number of measurements made; thus brief, short measurements are less precise than measurements taken over longer spans in time and space. Five illustrative applications demonstrate configurations where the DTS approach could be used: (1) lake bottom temperatures using existing communication cables, (2) temperature profile with depth in a 1400 m deep decommissioned mine shaft, (3) air-snow interface temperature profile above a snow-covered glacier, (4) air-water interfacial temperature in a lake, and (5) temperature distribution along a first-order stream. In examples 3 and 4 it is shown that by winding the fiber around a cylinder, vertical spatial resolution of millimeters can be achieved. These tools may be of exceptional utility in observing a broad range of hydrologic processes, including evaporation, infiltration, limnology, and the local and overall energy budget spanning scales from 0.003 to 30,000 m. This range of scales corresponds well with many of the areas of greatest opportunity for discovery in hydrologic science. The frequency shift mechanisms in Raman backscattered light consists of two components, namely, Stokes and anti-Stokes components (Gasser et al., 2022) The variation in temperature does not affect the amplitude of the Stokes components, while the amplitudes of anti-Stokes components vary dynamically in accordance with temperature changes.

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The operation method of Rayleigh scattering is based on elastic scattering (i.e., scattering without frequency variations) where the scattered power is directly proportional to the incident power which makes it attributable to nonpropagation density fluctuations [67]. Brillouin scattering can be measured based on spontaneous or simulated ways; however, identification of the wavelength shift of the scattered light acts as a key means of measuring Brillouin scattering [66]. One of the benefits of pipeline leakage detection using fiber optics is the ability to detect small leaks [64]. Moreover, the potential of monitoring long pipelines and capability to accurately functioning in both subsea and surface pipeline networks can also be considered as another benefit of fiber optic-based systems [4]. However, its shortcomings include short lifespan and the inability to estimate the rate of leakages. Besides, the installation of fiber optics system over a large and complex pipeline network is challenging as optical fibers are fragile. Even in the purest optical fibers, light is scattered as a result of the disordered (noncrystalline) structure of glass. Three primary modes of scattering are Rayleigh (elastic), Brillouin, and Raman (both nonelastic). The elastic scattering gives rise to a backscattered signal with no wavelength change, while the two nonelastic scattering phenomena result in light at wavelengths greater than (Stokes) and less than (anti-Stokes) the primary laser light (Fig. 6.39). In the case of Brillouin scattering, the effect is the result of subtle density shifts in the fiber caused by electromagnetic forces from the passage of intense laser light. These density changes propagate as acoustic waves, or phonons, giving rise to an intense resonant phenomenon. The wavelength shift of the Stokes and anti-Stokes scattered light

FIGURE 6.39 Diagram of Rayleigh, Raman, and Brillouin return scattering intensity below (Stokes) and above (anti-Stokes) the frequency of the injected light (Selker et al., 2006).

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is then proportional to the acoustic velocity of the fiber, which is a function of the fiber density. This velocity is highly correlated to the GeO2 content of the fiber, which varies by manufacturer and is not included in fiber specifications, thus each producer’s fiber must be calibrated. As seen for the Bragg gratings, the density thus measured can be used to determine changes in temperature or stress. Standard fiber-optic communication cables hold the fiber in a stress-free condition, ideally suited to the temperature measurement application, as shown in Fig. 6.2 where the lake bed temperature is shown for three dates using Brillouin scattering. Though beyond the scope of this article, there are two very different strategies to measure Brillouin scattering, referred to as spontaneous and stimulated. While quite different with respect to the tools of measurement, the overriding principles and limitations are similar. The key to making a Brillouin scattering measurement is the identification of the shift in wavelength of the scattered light. Because the scattered light wavelengths fall into a Gaussian distribution, the precision of determination of the center of the shift is a statistical computation limited by the standard deviation of this distribution to about 6 0.1 C. Since the measurement relies on taking averages of many independent backscatter events, the precision of the reading is a function of the time allowed for sampling. Thus the precision will be less for rapidly changing temperatures, with the reported value reflecting the average temperature over the sampling interval. The time domain-based spatial resolution of these measurements is limited by the length of the optical pulse required to activate the scattering through electromagnetic forces, yielding a best resolution of 0.5 to 1.0 m as a result of the narrow band process limiting the optical signal to a bandwidth of about 100 MHz. Brillouin scattering can be made on standard single-mode fiber-optical cables as employed in telecommunications, as was the case in the study shown in Fig. 6.40 under Lake Geneva. Commercial Brillouin-based DTS systems have the capability to measure along cables of lengths up to 30,000 m, with possibilities of extension up to 150,000 m (e.g., Omnisens, Lausanne, Switzerland). FIGURE 6.40 Temperature transects taken between France (south) and Switzerland (north) using existing communication fibers under Lake Geneva obtained using stimulated Brillouin scattering (Selker et al., 2006).

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Several pipeline leakage detection systems based on fiber optic approaches have been proposed in the literature. The effectiveness of using distributed optical fiber for pipeline leak detection has been reported by Du et al. (2017). In general, optical fiber is used for two functions: signal transmission and sensing. The leak position is determined using the time order of the anti-Stokes light received at the measuring station. Leakage detection of the heat pipe network is a systematic engineering process, according to whether the contact leakage and detection principle can be divided into direct and indirect detection methods (Du et al., 2017). Direct detection methods commonly used include: • • • • •

measuring temperature method; isolation method; valve auscultation and radiation tracking method; infrared thermal imaging; and optical fiber leakage detection method.

When the heating pipeline leakage, pipeline pressure, temperature, liquid flow, sound, and other physical quantities will change abnormally, the abnormal changes of these quantities can reflect the operation status of the heating pipeline network, determine whether the leak occurred, and further determine the leak location; this method is called the indirect method. The above methods have their own advantages and disadvantages, the direct detection method has high detection accuracy, but the cost is expensive; the indirect detection methods often require intermittent detection, and may not be able to determine the exact leakage accident. A similar study based on a macrobend coated fiber optic was proposed by Ong et al. (2017). In this paper, a simple fabricated and low-cost acoustic vibration sensor based on macrobend coated single-mode fiber (SMF-28) was proposed and developed. The fiber optic sensor comprises a bending structure and the macrobending loss was employed as the sensing mechanism for the detection of the leakage of a pipeline at low frequency. The measurement system involving the proposed fiber sensor was presented and investigated. Through this system, the fiber sensor is characterized by measuring the power loss corresponding to the vibration at various bending radii and the number of wrapping turns. Furthermore, the proposed fiber sensor was also implemented in a field test (water pipeline) and it was able to detect vibrations at the frequency range of 20
2500 Hz. Water ingress which commonly occurs in a low-pressure gas pipeline distribution network is a major challenge in subsea pipeline systems. This occurs whenever groundwater enters the pipeline through a crack point and blocks the flow channel. In an effort to detect and determine the location of water ingression, a temperature distribution sensing mechanism based on fiber optics was experimentally studied by Wang et al. (2017a,b). In order to find the location of water ingress, the DTS system has been used experimentally. The results show significant temperature change immediately after the onset of water ingress, and with data postprocessing based on temporal difference, the location information of the leak can be obtained. With a selected time window of interest, the inclination of gas pipeline is also indicated by the differenced temperature profiles. The DTS system is still capable of identifying the position, even if the location of water ingress is changed. A recent study reported the design of a distributed fiber Bragg grating (FBG) hoop strain measurement system in combination with a support vector machine algorithm for

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continuous gas pipeline monitoring as well as leakage localization (Jia et al., 2019). Series of terminal hoop strain variations are extracted as the input variables to achieve multi regression analysis as to localize the leakage point. The parameters of different kernel functions are optimized through fivefold cross validation to obtain the highest leakage localization accuracy. The results show that when taking RBF with optimized C and γ values, the localization MSE reaches as low as 0.043. The antinoise capability of the SVR model was evaluated through superimposing Gaussian white noise of different levels. From the simulation study, the average localization error is still acceptable (  500 m) even in a 5% noise situation. The influence of hoop strain sensing points as input variables was also investigated. The system with more hoop strain sensing points shows more stable capability for different level noises. The results demonstrate the feasibility and robustness of the SVR approach using multihoop strain measurements for pipeline leakage localization.

6.3.4 Vapor sampling method Vapor sampling is generally used to determine the degree of hydrocarbon vapor in the pipeline environment. The vapor or liquid sensing tube-based leak detection method involves the installation of a tube along the entire length of the pipeline. If a leak occurs, the content of pipe makes contact with the tube. The tube is full of air at atmospheric pressure. Once the leak occurs, the leaking substance penetrates the tube. In order to assess the concentration distribution in the sensor tube, a column of air with a constant speed is forced into the tube. There are gas sensors at the end of sensor tube. Every increase in gas concentration leads to a peak in gas concentration and its size is an indication of the size of the leak. The detected line is equipped with an electrolytic cell. This cell diffuses an exact volume of test gas into the tube constantly. This gas along with air passes through the whole length of the sensor tube. When the test gas travels through the detector unit, it produces an end peak. So, the end peak is a sign of the whole length of the sensor tube. Leak localization is carried out by calculating the ratio of end peak arrival to leak peak arrival (Golmohamadi, 2015). Fig. 6.41 illustrates sensor hose positioning in the pipeline for maximization of the system effectiveness. One shortcoming of this method is that it is rather slow, which is not practical, and also the cost is prohibitive. The other drawback of vapor sensing tubes is the difficulty of their application in pipelines above ground or in deep sites. Although, it is applicable in gas storage tank systems, it is also suitable to determine gas discharges into the environment surrounding the pipeline.

6.3.5 Infrared thermography Temperature is one of the most common indicators of the structural health of equipment and components. Faulty machineries, corroded electrical connections, damaged material components, etc., can cause abnormal temperature distribution. By now, infrared thermography (IRT) has become a mature and widely accepted condition monitoring tool where the

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Pump

Gas detector Gas concentration

Pump time FIGURE 6.41

Sensor hose system for pipeline leakage detection.

temperature is measured in real time in a noncontact manner. IRT as a contactless and noninvasive condition monitoring tool is also applicable for various condition monitoring applications, such as heat transfer, and tensile failure in concrete and masonry bridges. Pipeline leakage detection systems based on the IRT mechanism are also applicable for the detection of pipelines leakages. IRT is an infrared image-based technique that can detect temperature changes in the pipeline environment using cameras in the infrared range of 900
1400 nm. The image captured using an IR thermography camera is referred to as a thermogram. The basic function of thermography cameras is illustrated in Fig. 6.42. Since changes in temperature measurements are one of the common indications of gas discharge in the pipelines’ surroundings, therefore, using IRT for pipeline monitoring has become widely accepted due to its capability to measure temperature changes in real time and in a noncontact manner (Bagavathiappan et al., 2013). IRT enables early detection of equipment flaws and faulty industrial processes under operating condition, thereby reducing system down time, catastrophic breakdowns, and maintenance costs. The last three decades has witnessed a steady growth in the use of IRT as a condition monitoring technique in civil structures, electrical installations, machineries and equipment, material deformation under various loading conditions, corrosion damage, and welding processes. IRT has also found its application in nuclear, aerospace, food, paper, wood, and plastic industries. With the advent of newer generations of infrared camera, IRT is becoming a more accurate, reliable, and cost-effective technique. Bagavathiappan et al. (2013) reviewed the development of IRT as a noncontact and noninvasive condition monitoring tool for machineries, equipment and processes. Various conditions monitoring applications are discussed in detail, along with some basics of IRT, experimental procedures, and data analysis techniques, along with sufficient background information. Thermal cameras are effective devices for sensing objects of various shapes with different material properties from any perspective. The object acquired using a thermal camera can be processed to recognize anomalies in the pipeline environment through the warm and cooler areas displayed in the thermal image with a different color in that particular environment. Fig. 6.43 illustrates the experimental setup of a typical IRT-based system for anomaly detection in a pipeline environment. Thermography can be divided into two categories: active and passive thermography. Active thermography features the area of interest

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FIGURE 6.42 Basic functions of an IR

Object

thermography camera.

Atmosphere

Scanning

Condensing

Synchronisation

Detection

Amplification Display

FIGURE 6.43 Experimental setup of infrared thermography-based system for anomalies monitoring.

with the background thermal contrast, while the area of interest is focused on temperature variation and background in passive thermography. Unlike other temperature measurement mechanisms, such as resistance temperature detectors (RTDs), and thermocouples, IRT provides contactless, noninvasive, real-time, and distributed measurement of temperature across a continuous region. IRT can remotely measure the temperature distribution of an object and provide a visual image that indicates the degree of the data measured in that region with different colors. Improvements of IRT have been ongoing for several decades. Details of the origin and theory of IRT have been presented by Meola (2012). IRT has been widely used in pipeline monitoring. An innovative method of detecting pressure air and gas leakages using passive IR thermography was reported by Kroll et al. (2012). In their approach, the fundamental principle of IRT was used to differentiate various kinds of anomalies from thermal images using basic image segmentation algorithms to distinguish the defect areas in the images.

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Jadin and Ghazali (2014) presented a method for detecting gas leaks using infrared image analysis. Through an image filtering technique, the target region of interest is enhanced and segmented to extract the leaky regions. The image feature is extracted to identify the leakage. From the experimental result, it shows that this system is effective in detecting the presence of gas leakages in a real industrial problem. The use of IRT systems for pipeline condition monitoring enables timely detection of anomalies in the pipeline network, thereby reducing the loss associated with gas wastage. Besides, the complexity of IRT system integration is not high. The major components to set up the system are a camera stand, an infrared camera, and a display unit for visualization of the acquired infrared thermal images. Moreover, the benefits of the IRT system include efficient transmission of the scan objects into a visualization form, fast response time, and ease of use. The operation of such systems is so straightforward that no specially trained or experienced personnel are required for the monitoring task. IRT-based systems are suitable for any kind of pipeline size as well as various hydrocarbon fluids flowing through the pipelines. As early as 2003, Lewis et al. described a study which was conducted to test if an infrared camera could be used to detect gas leaks accurately by identifying them as anomalies. They examined the applicability and limitations of the technique by investigating fundamental factors such as weather conditions, ground conditions and distance of sensor from source. They also describe a test case conducted to reinforce the findings. It concluded that unless all the fundamental factors are clearly understood and addressed, the technique currently can only be used as a screening tool rather than as a precise tool to detect landfill gas leakages. However, the cost of a high-resolution infrared camera is very expensive. Moreover, quantifying a leak orifice of less than 1.0 mm using IRT-based systems is challenging. In an attempt to address these shortcomings, a leakage quantification mechanism using a combination of infrared thermography and ultrasound methods was proposed by Dudi´c et al. (2012). They described and compared two different noncontact methods for compressed air leakage quantification: ultrasound and infrared thermography. The potential and limitations of these technologies were analyzed, as well as the reliability and accuracy of results thus obtained. From the results presented in that paper, it can be concluded that thermography offers good results for leakage quantification from orifices greater than 1.0 mm, whereas ultrasound could be used for leakage detection for all dimensions of orifices, but for quantification purposes only for smaller leaks. As support for leakage quantification, they proposed diagrams of a leak flow as a function of sound level and as a function of detected temperature change. They also describe a study which was conducted to test if an infrared camera could be used to detect gas leaks accurately by identifying them as anomalies. It examined the applicability and limitations of the technique by investigating fundamental factors such as weather conditions, ground conditions and distance of sensor from source. The paper also describes a test case conducted to reinforce the findings. It concluded that unless all the fundamental factors are clearly understood and addressed, the technique currently can only be used as a screening tool rather than as a precise tool to detect landfill gas leakages. For this reason, it would be difficult to use the technique as a basis for modeling gas emission from landfills.

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The reported results indicate that thermography is appropriate to quantify pipeline orifices larger than 1.0 mm, while ultrasound was proven to be usable for all orifice dimensions. A similar study by Adefila et al. (2015) used combined thermal images (thermograms) and a platinum RTD method to achieve accurate spot temperature measurements. The study employed an experimental flow rig with an internal diameter of 50 mm and the volumetric rate of the leakage was determined using numerical computation.

6.3.6 Emerging methods Several techniques fall under this category. They are: • spectral scanners; • Lidar systems; and • electromagnetic reflection. Spectral scanners are passive sensors that analyze solar light reflected by a material. It detects pipeline leakages by comparing spectral signatures against a normal background. The multispectral scanner system sensors are line scanning devices observing the Earth perpendicular to the orbital track. The cross-track scanning was accomplished by an oscillating mirror; six lines were scanned simultaneously in each of the four spectral bands for each mirror sweep. The forward motion of the satellite provided the along-track scan line progression. Lidar (light detection and ranging) systems use pulsed laser radiation as the illumination source to determine the presence of methane. The absorption of the energy by the laser along the pipeline length is determined using a pulsed laser detector. The emitted energy at different wavelengths is measured through electromagnetic reflection. Electromagnetic reflection and other leak detection mechanisms such as ultraviolet scanner, microwave radiometer and visual surveillance cameras are regarded as passive monitoring devices that work through detecting either the radiation emitted by leaked natural gas or the background radiation. This makes passive-based systems less expensive in general. Recent developments in Lidar technology have been in the areas of increasing resolution. For instance, Hall (2017) developed a LiDAR-based 3D point cloud measuring system that includes a base, a housing, a plurality of photon transmitters and photon detectors contained within the housing, a rotary motor that rotates the housing about the base, and a communication component that allows transmission of signals generated by the photon detectors to external components. In several versions of the invention, the system includes a vertically oriented motherboard, ceramic hybrids for selectively mounting emitters and detectors, a conjoined D-shaped lens array, and preferred firing sequences. The electromagnetic reflection method involves the use of an electromagnetic sensor for the detection of leaks/cracks in pipelines. As old metal pipes corrode they start to become brittle, resulting in the potential for cracks to appear in the pipes. In addition corrosion can build up resulting in a restricted fluid flow. Using an electromagnetic (EM) wave sensor to monitor the signal reflected from the pipes in real time, provides the necessary information to determine where a leak in the pipe has occurred (Goh, 2011). Analysis of the reflected signal can provide the operator with information about the condition and position of a leak

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within the pipe. Goh’s doctoral thesis is the first research on EM waves for leak detection in water pipelines. This project involves the design and construction of an EM sensor operating at frequencies in the range of 240
560 MHz, and at a power of OdBm. The sensor is launched into the water pipeline through any existing hydrant and is moved along the pipeline to check for leaks. The simulation software high frequency structure simulator was used to model the pipe section as a circular waveguide cavity, and also for antenna simulation. The monopole and loop antenna were designed to determine the best antenna for this project. The printed circuit board (PCB) design package Eagle was used to provide the surface mount layout for the sensor, and the PCB board was fabricated by using a computer numerical control (CNC) routing machine. Finally the graphical interface package LabVIEW was used to control the frequency sweep for the sensor and to capture the data from the sensor. Based on the findings of this project, the EM wave sensor could be used to determine a leak up to a 0.9 correlation limit using low-cost RF electronic devices. Table 6.9 provides a summary, along with the strengths and weaknesses of the exterior leak detection techniques. 6.3.6.1 Visual/biological leak detection methods Visual/biological methods of detecting leakages refer to the traditional process of detecting oil spillage in pipeline surroundings using trained dogs, experienced personnel, smart pigging, or helicopters/drones. This method usually utilizes trained personnel who walk along the pipelines and search for anomalous conditions in the pipelines environment. Trained observers can recognize the leaks through visual observation or smelling the odor coming out from crack point. Similarly, the noise or vibrations generated as oil escapes from rupture point also are applicable in this method for detecting and locating pipeline failures. Both dogs and smart pigging function in a similar way to the experienced personnel. The pig is sometimes equipped with sensors and data recording devices such as fluorescent, optical camera, or video sensors with great sensing range if the visibility level is high. A trained dog is more sensitive to the odor of certain gases than human beings or pigging in some cases (Mandal, 2014). Mandal (2014) identified the state-of-theart in gas leak detection and localization methods. He evaluated the capabilities of leak detection techniques in order to identify the advantages and disadvantages of using each leak detection solution. The common leak detection techniques used in the Titas Franchise Area (TFA) were critically analyzed to find out the necessity of using modern technology to detect gas leakage. Biological methods are used in TFA to detect a potential leak. Modern technology is to be used in TFA for reducing gas loss as well as financial loss by maximizing its proper usages. Dogs’ superior olfactory abilities and high trainability are suitable for a wide range of chemical and biological detection applications, including petroleum leaks. However, methods for testing canine olfactory detection vary widely and such variation can influence the interpretation of results. Furthermore, systematic reviews of canine olfactory detection literature have identified a major lack in reporting the information necessary to evaluate the validity of the results, as well as a prevalence of methodological confounds that could bias their interpretation (Lazarowski et al., 2020). They reviewed the various critical features

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TABLE 6.9 Summary of exterior pipeline leak detection methods. Methods

Principle of operation

Strengths

Weaknesses

Acoustic emission

Detect leaks by picking up intrinsic signals escaping from a perforated pipeline.

Easy to install and suitable for early detection, portable and cost-effective.

Sensitive to random and environmental noise, prone to false alarms and not suitable for small leaks.

Fiber optics sensing

Detect leaks through the identification of temperature changes in the optical property of the cable induced by the presence of leakage.

Insensitive to electromagnetic noise and the optical fiber can act both as sensor and data transmission medium.

The cost of implementation is high, not durable, and not applicable for pipelines protected by cathodic protection systems.

Vapor sampling

Utilize hydrocarbon vapor diffused into the sensor tube to detect trace concentrations of specific hydrocarbon compounds.

Suitable for detecting small concentrations of diffused gas.

Time taken to detect a leak is long, not really effective for subsea pipelines.

Infrared thermography

Detect leaks using infrared image techniques for detecting temperature variations in the pipeline environment.

Highly efficient power for transforming detected objects into visual images, easy to use and fast response time.

Quantifying leak orifices smaller than 1.0 mm using IRTbased systems is difficult.

Ground penetration radar

Utilize electromagnetic waves transmitted into the monitoring object by means of moving an antenna along a surface.

Timely detection of leakage in underground pipelines, reliable and leak information is comprehensive.

GPR signals can easily be distorted in a clay soil environment, costly and require highly skilled operator.

Fluorescence

Proportionality between the amount of fluid discharged and rate of light emitted at a different wavelength.

High spatial coverage, quick and easy scanning for leaks.

Medium to be detected must be naturally fluorescent.

Electromechanical impedance

Utilize mechanical impedance A single piezoelectric changes deduced by the incident transducer can serve as both of pipeline defect. sensor and actuator.

It is only applicable for metal pipelines, operational limitations in high temperature environments.

Capacitive sensing Measuring changes in the It can be employed for dielectric constant of the detection in nonmetallic medium surrounding the sensor. targets.

Requires direct contact with the leaking medium.

Spectral scanners

Comparing spectral signature against normal background.

Capable of identification of oil type (light/crude) and thickness of the oil slick.

The amount of data generated by a spectral scanner is large which limited its ability to operate in nearly real-time.

Lidar systems

Employed pulsed laser as the illumination source for methane detection.

Able to detect leaks in the absence of temperature variation between the gas and the surroundings.

High cost of execution and false alarm rate.

Electromagnetic reflection

Measure emitted energy at different wavelengths.

It can indicate leak location.

It can be affected by severe weather.

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that should be included in the design and implementation of olfactory detection studies in order to ensure the quality and reproducibility of results. They argue for increased rigor in the examination of canine odor detection performance, but correctly pointed out that the inherent variability of any biological system and technical challenges in its assessment across its wide operational field must be considered. Also, dogs are not effective for prolonged operation for more than 30
120 minutes of continuous searching due to fatigue. These on-site inspection methods can only be applied to onshore or shallow offshore pipeline networks. Besides, the detection time is also based on the frequency of inspections which normally take place in some countries such as the United States at least once every 3 weeks (Murvay and Silea, 2012). The recent development of remotely operated vehicles (ROVs) has transformed the operation style of offshore oil transportation operators. It has been shown that ROVs are durable for performing subsea pipeline inspection tasks and functioning in deep water that cannot be accessible by dog, pigging, or human divers (Shukla and Karki, 2016). Successful implementation of robotics is a critical example of how robotic assistance and automation is the only option for safe and cost-effective production of oil in the foreseeable future. Teleoperation of unmanned drilling and production platforms, remoteoperated vehicles (ROVs), autonomous underwater vehicles (AUVs), underwater welding, welding robots for double hulled ships, and underwater manipulators are such key robotic technologies that have facilitated the smooth transition of offshore rigs from shallow waters to ultradeep waters in modern times. Considering the sensitivity of the product and the difficulty of the environment, most of these technologies fall into the semiautonomous category, where the human operator is in the loop for providing cognitive assistance to the overall operation for safe execution. The operation principle of ROVs is based on teleoperation that involves a master
slave system. The slave is a ROV which is designed to interact with the extremely hazardous subsea environment while the master human operator is located in a safe place to remotely control the slave robot’s motions using input devices, like joysticks or haptic devices (Shukla and Karki, 2016). All robot commands, sensory feedback, and power are sent through an umbilical cable connecting the ROV and the deployment vessel. The emergence of autonomous underwater vehicles (AUVs) in subsea pipeline inspection and monitoring has reduced the extent of human operator involvement in unmanned vehicles through the implementation of intelligent control machinery and thus has drastically lowered the chance of human casualties. Though, the operation principle of AUVs is similar to the teleoperation of ROVs, only a limited number of skilled operators are required for supervisory control of AUVs. Anisi and Skourup (2012) developed a strategy based on a step-wise approach involving the development and validation of the technology in increasingly demanding settings. This started with proof-of-concept demonstrations in their indoor test facility located in Oslo, Norway. Taking this one step further, robots and applications were further developed, tested, and validated in a colocated outdoor test facility. This is normally an intermediate step before bringing demonstrators onto real oil and gas facilities. The use of unmanned vehicles for pipeline inspection has the advantage of being a remote operating system; making it suitable for inspection in a remote and hazardous environment. The lower cost of maintenance and higher operation safety are also some of the advantages of unmanned vehicles. Unfortunately, these systems also have drawbacks.

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Additionally, bad weather conditions such as clouds, winds, or other climatological agents can restrict the performance of these vehicles. There are also legal constraints for the use of the unmanned system in some certain areas due to safety concerns because unmanned vehicles usually lack the onboard capacity to sense and avoid other AUVs in advance. UAV systems prototyped to monitor pipelines were reviewed by Go´mez and Green (2017). They provided a useful summary of sensors on board a UAV for monitoring oil and gas pipelines. The type and quality of sensors carried onboard the platform determine the final information obtained from the mission. Although the range of sensors available for small-scale UAVs is forever increasing due to miniaturization and advancements in battery technology (Table 6.10), limitations associated with size, weight, and mechanics still remain (Allen et al., 2015). Selecting a combination of platform and sensor to provide the necessary data in adequate conditions for monitoring and mapping oil and gas pipelines remains a challenge, and for some of the most adequate oil or gas leak detection techniques (e.g., fluorescence), there is still no sensor (e.g., laser fluorosensor) adapted to UAV platforms. The main sensor types with commercial adaptations to UAV mechanics that can be used for monitoring oil and gas pipelines are listed in Table 6.10. Table 6.11 summarizes a few examples of current pipeline monitoring systems that illustrate diverse case scenarios. Note that there is a different monitoring goal in each case, with a corresponding appropriate strategy and related combination of platform and sensor. Bolted connections are widely used in pipeline systems, for which joints in flanges are ubiquitous. Bolt looseness is one of the most important factors leading to pipeline failures. At present, most of the detection methods for bolt looseness do not achieve a good balance between cost and accuracy (Yu et al., 2021). Yu et al. (2021) proposed a detection method of a small angle of bolt loosening in a timber structure, using deep learning and machine vision technology. Firstly, three schemes were designed, and the recognition targets were the nut’s own specification number, rectangular mark, and circular mark, respectively. The Single Shot MultiBox Detector (SSD) algorithm was adopted to train the image datasets. The scheme with the smallest identification angle error was the one identifying round objects, of which the identification angle error was 0.38 degrees. Then, the identification accuracy was further improved, and the minimum recognition angle reached 1 degree. Finally, the looseness in a four-bolted connection and an eight-bolted connection were tested, confirming the feasibility of this method when applied on a multibolted connection, and realizing a low operating cost and high accuracy. Nguyen et al. (2016) proposed a vision-based algorithm to identify bolt-looseness in steel structure bolted flange connections. They developed an algorithm using image processing techniques to identify bolt-loosening in bolted connections of steel structures. The basic concept was to identify rotation angles of nuts from a pictured image, and mainly consisted of the following three steps: (1) taking a picture of a bolt joint, (2) segmenting the images for each nut by image processing techniques, and (3) identifying the rotation angle of each nut and detecting bolt-loosening. By using the concept, an algorithm was designed for continuous monitoring and inspection of the bolt connections. As a key image processing technique, the Hough transform2 was used to identify the rotation 2

The Hough transform is a feature extraction technique used in image analysis, computer vision, and digital image processing. The purpose of the technique is to find imperfect instances of objects within a certain class of shapes by a voting procedure.

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TABLE 6.10 Selection of sensors suitable for monitoring oil and gas pipelines; strengths and weaknesses for the purpose and typical performing tasks. Type

Strengths

Weaknesses

Typical task

Passive Visible (wavelength 0.38
0.76 μm)

• Visual interpretation

• Only suitable in daylight conditions • Limited by atmospheric effects such as clouds, haze or smoke • Only suitable in daylight conditions • Limited by atmospheric effects such as clouds, haze or smoke • Not visible for human eye but sensed with indium gallium arsenide (InGaAs) sensors • Scarce production of detector material (InGaAs)

• Infrastructure inspection • Spill detection

• Reference data for comparison is needed

• Leak detection • Leak monitoring

• Reference data for comparison is needed

• Characterization and monitoring of environmental condition

• Library needed

• Characterization and monitoring of environmental condition

• Redundant information • Typically lower spatial resolution than stills

• Monitoring leakage /spill

• Augments weight

• Infrastructure inspection

• Limited by wind

• • • •

Multispectral (multiple • Visual interpretation bands) • Vegetation indices SWIR (wavelength 0.9
1.7 μm)

Thermal IR (8
14 μm)

Near infrared (NIR) (wavelength 0.76
14 μm) Hyperspectral (hundreds of bands)

Video

Stereo cameras

Gas IR camera Active

Lidar

• Very sensitive in low-light conditions • Low power consumption (thermoelectric cooler) • Identification of materials and substances • Enables detection of leaks • Night vision • Vision through smoke, haze, cloud • Sensitive to vegetation condition • Identification of materials and substances • Flexible/customizable number and resolution of spectral bands • Life monitoring if video downlink enabled • Enables generation of 3D imagery • Enables generation of 3D imagery • Can be used as the basis for navigation systems • Enables detection of leaks • Night vision • Enables 3D measures • High precision

• • • •

Power consumption Dependable on inertial navigation system Lack of commercial sensors Difficulties for miniaturization (size and weight)

• Characterization and monitoring of environmental condition • Night time characterization and monitoring of environmental condition

Leak detection Leak monitoring Background characterization (3D) Infrastructure inspection

Radar

• Detection of oil spills in water • All weather conditions • Day and night conditions

• • • •

Laser gas detector

• Measurement of gas emissions (methane concentration) • Early detection of pipeline misfunction • Underground pipeline leak detection • Day and night conditions • No false detections • Day and night conditions • Reliable detector of oil in snow and ice

• • • •

Power consumption Differential imagery needed Lack of commercial sensors Difficulties for miniaturization (size and weight) Power consumption Limited range of action (B100 m; ,500 m) Imprecision in windy conditions Small sampling area

• • • •

Power consumption Lack of commercial sensors Requires clear atmosphere (no fog) Specialized processing

Laser fluorosensor

• Leak detection • Leak monitoring

• Leak detection • Leak monitoring

• Leak detection • Leak monitoring

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TABLE 6.11 Examples of operational UAV systems for monitoring oil and gas pipelines. Case 1: British Petroleum and AeroVironment (BP 2016)

Goal: Detection of deteriorated Platform: Puma AE infrastructure and areas vulnerable to Sensor: LiDAR or EO/IR flood Task: Inspection of the oil field area Technique: Production of 3D maps of the Prudhoe Bay oil field roads, pipelines and well pads

Case 2: ConocoPhillips and Boeing (FAA 2013)

Goal: Meet environmental and safety rules before drilling on the sea floor Task: Surveying marine mammals and ice areas in the Arctic

Platform: ScanEagle X200 Sensor: EO/IR imagers and video

Technique: Offshore surveys taking off from a vessel. Controlled by a pilot on the Westward Wind, the ScanEagle sends real-time video and telemetry to the ground control system on the vessel Case 3: Aeronautics (Aeronautics 2015)

Goal: Maintain security in offshore oil fields Task: Patrolling offshore fields

Platform: Aerostar Sensor: IR camera

Technique: Differential thermal imaging, Ultra Wideband, or differential RF, subsurface probing Case 4: British Petroleum and University of Alaska Fairbank (Aeryonlabs 2011)

Goal: Leak detection and change identification in Alaska Task: Pipeline inspection

Platform: Aeryon Scout Sensor: High-resolution visual and IR cameras

Technique: Observation from near ground level, with top and side pipeline flights. Detection of hotspots with thermal images allowing closer inspection; change detection through repetitive flights

angles of nuts, and then bolt-loosening was detected by comparing the angles before and after bolt-loosening. Then the applicability of the proposed algorithm was evaluated by experimental tests for two lab-scaled models. A bolted joint model which consisted of a splice plate and eight sets of bolts and nuts with a 2 3 4 array was used to simulate the inspection of bridge connections, and a model which consisted of a ring flange and 32 sets of bolt and nut was used to simulate continuous monitoring of bolted connections in wind turbine towers. A similar vision-based monitoring technique for the detection of bolted joints looseness in wind turbine tower structures was proposed by Park et al. (2015), which can be adopted to pipeline monitoring in a fairly straightforward fashion. They proposed a novel visionbased bolt-loosening monitoring technique for bolted joints connecting tubular steel segments of the wind turbine tower (WTT) structure. Firstly, a bolt-loosening detection algorithm based on image processing techniques was developed. The algorithm consists of five steps: image acquisition, segmentation of each nut, line detection of each nut, nut angle estimation, and bolt-loosening detection. Secondly, experimental tests were conducted on a lab-scale bolted joint model under various bolt-loosening scenarios. The bolted joint model, which consisted of a ring flange and 32 sets of bolt and nut, was used for simulating the real bolted joint connecting steel tower segments in the WTT. Finally, the feasibility of the proposed vision-based technique was evaluated by bolt-loosening

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monitoring in the lab-scale bolted joint model. Wang et al. (2020) proposed a new visionbased bolts looseness detection method to address the issues of the difficulty in detecting the status of bolt image acquired from any arbitrary perspective in a high-performance bolt looseness recognition model. As regular inspection for the bolt connection in inaccessible areas is difficult and costly, computer vision technology provides a suitable noncontact approach for real-time bolt looseness detection as an alternative to inspection approaches. However, computer vision still suffers from various impracticalities. In this paper, a new vision-based bolt looseness detection method was designed and implemented with the bolt images acquired by a camera at arbitrary positions around the bolts. The new method includes the perspective transformation of original images acquired, identification of bolt positioning with the convolutional neural network digit recognition, detection of bolt rotation angles using the Hough transform line detection, and density-based spatial clustering of applications with noise. To demonstrate the effectiveness of the new method, an experiment with bolted connections was set up. The experimental results demonstrated that the new method can accurately detect the looseness of the bolts in the bolted connection. The algorithm developed shows high capability to identify the mark on the bolt and bolt position on the flange connection in offline mode. In order to enhance the robustness of this method further online training is required. Similarly, the method should be improved to be able to recognize bolts looseness in a pool of large flag bolts.

6.3.7 Interior/computational methods Interior or computational methods utilize internal fluid measurement instruments to monitor parameters associated with fluid flow in pipelines. These systems are used to continuously monitor the status of petroleum products inside the pipeline such as pressure, flow rate, temperature, density, volume and other parameters which quantitatively characterize the released products. By fusing the information conveyed from internal pipeline states, the discrepancy between two different sections of the pipeline can be used to determine the occurrence of leakage based on various methods, namely mass-volume balance, negative pressure waves, pressure point analysis, digital signal processing and dynamic modeling. 6.3.7.1 Mass-volume balance This is a relatively simple method for detecting leaks in liquid transmission pipelines. Its operation is based on the principle of mass conservation The methodology was outlined by Ostapkowicz (2016). They presented solutions of procedures (algorithms) applied to both negative pressure wave and gradient methods. These algorithms aimed at achieving a satisfactory level of efficiency of a single leakage diagnosis. The methods were evaluated in terms of their implementation with a minimum number of measuring devices. In the case of the negative pressure wave method, apart from the standard pressure transmitters to measure the pipeline pressure, also the use of nonstandard measuring devices, conventionally the so-called correctors, was considered. The signals generated by the correctors are characterized by a good correspondence between the measured signal representing a change in the pressure and measurement noise level and

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the overall pressure transmitter range. All this, in combination with the developed algorithm, which apart from detecting a leak, is aimed at precise identification of a change in the signal related to the wave pressure front, that is, the so-called inflection point, provides a high efficiency of leak detection. This has been proven by carrying out a number of experimental tests on a laboratory water pipeline. The tests involved simulations of both sudden and slow leakages. 6.3.7.2 Negative pressure wave Leak detection techniques using negative pressure waves (NPWs) are based on the principle that when a leakage occurs, it causes a pressure alteration as well as a decrease in flow speed which results in an instantaneous pressure drop and speed variation along the pipeline. As the instantaneous pressure drop occurs, it generates a negative pressure wave at the leak position and propagates the wave with a certain speed toward the upstream and downstream ends of the pipe. The wave contains leakage information which can be estimated through visual inspection and signal analysis to determine the leakage location by virtue of the time difference between when the waves reach the pipeline ends (Sang et al., 2006). A NPW-based leakage detection technique is cost-effective as it requires little in the way of hardware in the whole pipeline network to detect and locate leaks. When NPW signals are used to locate pipeline leaks, any noise will increase the error of location estimation. Thus, an adaptive noise reduction method based on variational mode decomposition (ANR-VMD) was proposed by Liu et al. (2021) to improve the accuracy of leak location. First, the number of decomposition layer of VMD is optimized by the minimum information entropy. Second, the effective intrinsic mode function components are selected using the correlation coefficient. Finally, these components are reconstructed to obtain the denoised signal. In real experiments, ANR-VMD obtains a smoother pressure signal, retained the signal waveform characteristics, and identified the evident NPW inflexion point. The location accuracy of ANR-VMD for six leak points was verified. The minimum positioning error of the wavelet and EMD methods was 3.51%, and the leakage could not be located when the error is high. The minimum error of ANR-VMD was 0.9%, and the maximum was 3.75%. This method has been widely employed in pipeline monitoring due to its fast response time and leak localization ability (Yu et al., 2009). Aiming at its shortcomings in reducing false alarms and improving location precision, a combined Kalman filter and discrete wavelet transform method for the leakage detection of crude oil pipelines has been proposed. In view of the nonstationarity of collected signals and excessive field noise, the Kalman filter (KF) is used for the preprocessing of pressure and flow signals at first, and then the leakage judgment and location of crude oil pipelines are carried out based on the filtered signals. The leakage location is obtained by extracting inflection points of the filtered pressure signal with the method of discrete wavelet transform (DWT). The field experiment results indicate that the method presented in this paper can reduce the false alarm rate effectively and improve detection sensitivity and location precision. However, it is only effective for massive instantaneous leaks and easily leads to false alarms due to the difficulty in differentiating between normal pressure waves and leakages. Similarly, the precise determination of the leak location using the time difference in pressure wave

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detection at the two ends of pipeline is another critical challenge of this method. In order to alleviate this shortcoming, several efforts have been devoted to improving the leak detection and localization mechanisms using NPW. Identification of the signal that indicates a leak and normal pipeline operation using structure pattern recognition was proposed by Hou and Zhang (2013). In the study of Peng et al. (2011), a negative pressure wave signal analysis system based on a Haar wavelet transformation was proposed. The authors demonstrated an effective way of detecting signal variations in the pressure wave signal and established a systematic way of using wavelet denoising schemes to overcome the destructive noise attenuation problem. The pressure wave signal created by a small leakage can be easily mixed with noise and background interference. This makes accurate signal detection and thus the oil spillage detection process challenging. An effective method of identifying small leakage signals using an improved harmonic wavelet was proposed by Yonghong and Zhenhua (2012). The proposed scheme was used to extract the pressure wave signal from the background noise, but the shortcoming of this approach is the decay rate of the pressure wave signal in the time domain. In order to address this issue, the authors adopted a window function to smooth the harmonic wavelet. Different methods of addressing the effect of background interference from leakage signals have been proposed in the literature. An independent component analysis (ICA) technique for separation of the characteristic signatures of the pressure wave signal mixed with the background noise was reported by Chen et al. (2010). 6.3.7.3 Pressure point analysis The pressure point analysis detection (PPA) method is based upon the statistical properties of a series of pressure or velocity pipeline measurements at one point being different before and after a leak occurs. Usually the data are collected from various types of sensors over a certain period of time and analysis is carried out. If the statistical pressure of the new incoming data is considerably smaller than the previous value or smaller than a predefined threshold, it indicates a leakage event. This method is considered as one of the fastest ways of detecting the presence of leakage in a pipeline based on the fact that the existence of leak always results in an immediate pressure drop at the leakage point. Bin Md Akib et al. (2011) presented a mathematical derivation for calculating the pressure before the leak as well as the pressure at the point of leakage. The pressure at the leakage point has a strong relationship with the mass flow rate of the substance, hence the derivation for the accidental leakage is also presented in that paper. The results show that it is possible that the result from the simulation works can be used as the input for the pressure point analysis method. By doing so, a lot of time can be saved in terms of collecting and sampling the data for leak detection system and more time can be used to improve the system itself. The most recent advancement of this technique has been in the areas of computational methods. Some of them were recently reviewed by Idachaba and Rabiei (2021). 6.3.7.4 Digital signal processing In digital signal processing approaches, the extracted information such as amplitudes, wavelet transform coefficients, and frequency response are employed to determine leakage events.

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A time-frequency technique for locating leaks in buried gas distribution pipes involves the use of cross-correlation of two measured acoustic signals on either side of a leak. This technique can be problematic for locating leaks in steel pipes, as the acoustic signals in these pipes are generally narrow-band and low frequency. Kim and Lee (2009) investigated experimentally the effectiveness of the time-frequency technique for detecting leaks in steel pipes. Then they followed up with another paper to identify the characteristics of this dispersive acoustic wave through analysis of the cut-off frequency using the timefrequency method experimentally and BEM (boundary element method) theoretically for the development of an experimental tool to analyze the leak signals in a steel pipe. The tool is based on experimental work and the theoretical formulation of wave propagation in a fluid-filled pipe. This tool uses the time-frequency method to explain some of the features of wave propagation measurements made in gas pipes. Leak noise signals are generally passed through a time-frequency filter for detection of impulse signal-related leakage. Generally, pipeline leak detection using digital signal processing involves five steps as illustrated in Fig. 6.44. The steps are: (1) initially internal sensors measure in-pipe pressure or flow; (2) after data acquisition, the acquired data is preprocessed to filter the background noise for efficient feature extraction; (3) in the feature extraction step, various statistical, spectral, and signal transform techniques are employed to extract relevant features to monitor the state of hydrocarbon fluid transport in the pipeline; (4) the pattern of the extracted feature is compared with the known preset signal or previous features for decision-making; (5) leakage detection is achieved through the comparison of the pattern with the threshold. Different signal processing techniques have been employed in this research domain. Some of the existing methods include: • • • •

wavelet transform; impedance method; cross-correlation; and Haar wavelet transform.

Jafari et al. (2022) proposed a new leak detection method based on an autoregressive with exogenous input (ARX) Laguerre fuzzy proportional-integral-derivative (PID) observation system. The objective of the paper was to propose a new leak detection method based on an autoregressive with exogenous input (ARX) Laguerre fuzzy proportional-integral-derivative

FIGURE 6.44

The architecture of pipeline leaks detection based on digital signal processing.

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(PID) observation system. In this work, the ARX
Laguerre model has been used to generate better performance in the presence of uncertainty. According to the results, the proposed technique can detect leaks accurately and effectively. Shibata et al. (2009) devised a leakage detection system using FFT. The proposed method detects pipe leak positions through analysis of the data obtained at a certain distance from the leakage point. The classification and discrimination of the orifice signals are carried out based on the obtained signal patterns. Lay-Ekuakille et al. proposed a spectral analysis of the leak detection system in a zigzag pipeline using the FDM. That study aimed to utilize the FDM as an improved alternative to FFT to minimize the FFT recovery error in a narrow pipeline network. Santos-Ruiz et al. proposed an online pipeline leakage diagnosis system based on an extended Kalman filter (EKF) and steady-state mixed approach. The efficiency of the method was evaluated using online detection, localization, and quantification of nonconcurrent pipeline leakages at different positions. The obtained results indicated an average error estimate of less than 1% of the flow rate and 3% of the leak localization. Sun et al. (2014) proposed a small leak feature extraction and recognition scheme for natural gas pipelines using local mean decomposition envelope spectrum entropy to decompose the leak signal into product function components. Based on the obtained kurtosis features, the principal product function components with higher leak information content were chosen for further processing. Sun et al. (2014) proposed a hybrid ensemble local mean decomposition (ELMD) and sparse representation for recognition of leakage orifices in a natural gas pipeline. An ELMD scheme was employed to perform adaptive decomposition of the leak signatures and acquisition of information feature of the leak signal based on different orifice scenarios. First, LMD is used to decompose the leakage signals into several FM
AM signals, that is, into product function (PF) components. Then, based on their kurtosis features, the principal PF components that contain most of the leakage information are selected. Wavelet packet decomposition and energy methods are used to analyze and then reconstruct the principal PF components. The Hilbert transform is applied to these reconstructed principal PF components in order to acquire the envelope spectrum, from which the envelope spectrum entropy is obtained. Finally the normalized envelope spectrum entropy features are input into the SVM as leakage feature vectors in order to enable leak aperture category identification. By analyzing the acquired pipeline leakage signals in field experiments, it was shown that this method can effectively identify different leak categories. Liu et al. (2019) proposed a new method of leak localization for a gas pipeline using acoustic signals. To solve the leakage problems, an acoustic leak-localization system was designed and researched for gas pipelines via experiments using four methods proposed for different application situations. The traditional method with two sensors installed at either end can be improved by a newly proposed combined signal-processing method, which is applied in cases where it is necessary to calculate the time differences with data synchronicity. For cases where data synchronicity cannot be ensured, a new method is designed based on velocity differences, involving the installation of two sensors at the same end separated by a small distance. When the time differences cannot be calculated accurately, two new methods based on the amplitude attenuation model were proposed, which include the two aforementioned methods of sensor installation. Using these four

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methods, the system can be applied to most situations. Next, a laboratory-scale experimental facility was established, and experiments performed with the same leakage point. Finally, the methods were verified and applied for leak-localization. The results provide a foundation for the proposed methods. The maximum experimental leak-localization errors for the four methods are 2 0.59%, 22.44%, 1.83%, and 2 11.68%. By using these novel methods, the system can be applied to protect and monitor natural gas pipelines.

6.3.8 Dynamic modeling Dynamic modeling describes those aspect of the system that are concerned with time and sequencing of the operations. Practically, every natural process is dynamic and thus in need of dynamic modeling. However, it is often a matter of too much data for a simple device to handle. In particular, pipeline systems are gaining considerable attention as they appear to be a promising technique for the detection of anomalies in both surface and subsea pipeline networks. In this approach, mathematical models are formulated to represent the operation of a pipeline system based on physics principles. The detection of leakages using this method is performed from two different points of views: (1) a statistical point of view, and (2) a transient point of view. From the statistical point of view, the system utilizes decision theory based on the assumption that parameters associated with fluid flowing remain constant except in the presence of anomalies along the pipeline (Kay, 2013). Hypothesis testing for detecting leakage is based on the uncompensated mass balance through the utilization of either single or multiple measurements carried out at different time instants. Detection of leakage in pipelines mainly requires the formulation of a mathematical model using fluid flow equations. The equations of state for modeling fluid flow include the equations of conservation of mass, conservation of momentum, conservation of energy, and states of the fluid. This method requires measurements of flow, temperature, pressure, and other parameters associated with fluid transport at the inlet and outlet of the pipeline or at several points along the pipeline. The transient event or noise levels are continuously being monitored using the discrepancy between the measured values and simulated values to detect the occurrence of leakages. Transient-based leak detection approaches have been proposed by the research community in various studies. The process is similar to history matching in conventional reservoir simulation practices (Abou-Kassem et al., 2020). As such, the accuracy of this technique depends on the numerical models used to simulate the fluid flow history.

6.3.9 State estimators/observers method State estimator or observer is a method that is based on dynamical modeling of flow process in the pipeline to estimate or observe variations in the variables associated with the fluid flow and to indicate the occurrence of fault as a result of pipe damage. This technique in a usual sense can be regarded as an auxiliary dynamical model for estimation of the internal parameters of a flow process (Besanc¸on, 2017). The state observers have been employed to reconstruct the state vector and estimate the missing variables

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in the flow process. A general review of recent observers in applied chemical process system was undertaken by Ali et al. (2015), who presented six different kinds of state estimators, including Luenberger-based observers, finite-dimensional system observers, Bayesian estimators, artificial intelligence-based observers, disturbances and fault detection observers, and hybrid observers. Observers are computational algorithms designed to estimate unmeasured state variables due to the lack of appropriate estimating devices or to replace high-priced sensors in a plant. It is always important to estimate those states prior to developing state feedback laws for the control and to prevent process disruptions, process shutdowns, and even process failures. The diversity of state estimation techniques resulting from intrinsic differences in chemical process systems makes it difficult to select the proper technique from a theoretical or practical point of view for design and implementation in specific applications. Ali et al. (2015) reviewed the applications of recent observers to chemical process systems and classified them into six classes, differentiating them with respect to their features, thus assisting in the design of observers. Furthermore, they provided guidelines in designing and choosing the observers for particular applications, and discussed the future directions for these observers. A leak detection and isolation algorithm that is based on a state estimation observer was proposed by Jime´nez Cabas (2018). Besides optimization algorithms, a novel method, based on a Lie´nard-type model, to diagnose single and sequential leaks in pipelines was proposed. In this case, the Lie´nard-type model describes the fluid behavior in a pipeline only in terms of the flow rate. This method was conceived to be applied in pipelines solely instrumented with flowmeters or in conjunction with pressure sensors that are temporarily out of service. The design approach starts with the discretization of the Lie´nard-type model spatial domain into a prescribed number of sections. Such discretization is performed to obtain a lumped model capable of providing a solution (an internal flow rate) for every section. From this lumped model, a set of algebraic equations (known as residuals) are deduced as the difference between the internal discrete flows and the nominal flow (the mean of the flow rate calculated prior to the leak). The residual closest to zero will indicate the section where a leak is occurring. The main contribution of the other method is that it only requires flow measurements at the pipeline ends, which leads to cost reductions. Some simulation-based tests in Pipeline Studio and, even more importantly, experimental tests illustrating the suitability of the proposed method were shown. Besanc¸on et al. (2007) proposed a direct observer model for detecting and estimating leaks in pipelines. In their approach, a simple way of obtaining a more efficient model was formulated using finite-dimensional approximation. Some direct on-line observerbased approaches for leak detection and isolation in pipelines are presented with validation by simulation. In case a number of possible leaks are to be detected, an observer aiming at the simultaneous estimation of magnitudes and positions of the leaks is given on the basis of some appropriate model on the one hand, and appropriate excitation on the other hand. Torres et al. (2014) investigated the use of both a high gain observer and an extended Kalman filter for monitoring pipeline flow processes. Experiments were carried out in two phases: the first phase considered the leak detection and isolation problem, and the second phase investigated friction estimation in the process. They proposed a high gain observer

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method to detect and isolate leakages in subterranean liquefied petroleum gas (LPG) pipelines. The authors connected a subobserver in cascaded form in order to generate residuals that allow the detection of leakages and isolating the region where a leakage occurred in the pipeline. Table 6.12 provides a summary of the strengths and weaknesses of the interior leak detection approaches.

6.4 Performance comparison of leak detection technologies Timely pipeline leak detection is a significant business issue in view of a long history of catastrophic incidents and growing intolerance for such events. It is vital to flag containment loss and location quickly, credibly, and reliably for all green- or brownfield critical lines in order to shut down the line safely and isolate the leak. Pipelines are designed to transport hydrocarbons safely; however, leaks have severe safety, economic, environmental, and reputational effects. Cramer et al. (2015) highlighted robust, reliable, and costeffective methods, most of which leverage real-time instrumentation, telecommunications, TABLE 6.12 Summary of the interior pipeline leak detection methods. Methods

Principle of operation

Strength

Weakness

Massvolume balance

Utilizes discrepancy between upstream and downstream fluid mass-volume for determining the leakage.

Low cost, portable, Leak size dependent, not straightforward and insensitive applicable for leak localization. to noise interference.

Negative Pressure wave

Utilizes negative pressure waves propagated due to pressure drops as a result of leakage.

Fast response time and suitable for leak localization.

Only effective for large instantaneous leaks.

Pressure point analysis

Monitor pressure variation at different points within the pipeline system.

Appropriate for underwater environments, cold climates and adequately functioning under diverse flow conditions.

Leak detection is challenging in batch processes where valves are opened and closed simultaneously.

Digital Utilizes extracted signal features signal such as amplitude, frequency processing wavelet transform coefficients, etc. from acquired data.

Good performance, suitable for Easily prone to false alarms, and detecting and locating leak can be masked by noise. positions.

Dynamic modeling

Applicable for leak detection and localization, fast and a large amount of data can be handled.

High computational complexity, expensive and labor intensive.

Suitable for reconstruction of the state vector and estimating the missing variable.

The limitations vary based on estimator classes such as poor convergence factors, computational complexity, discarding of uncertainties during simulation etc.

Detects leaks using the discrepancy between measured data and simulated values based on conservation equations and the equation of state for the fluid.

State Estimates the missing variables estimation using a set of algebraic equations that relates a set of input, output and state variables.

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6.4 Performance comparison of leak detection technologies

Comparison of performance analysis

supervisory control and data acquisition (SCADA), distributed control systems (DCS), and associated online leak detection applications. The purpose of this chapter is to review the underlying leak detection business issues, catalog the functional challenges, and describe experiences with available technologies. Internal and external techniques will be described, including the basic rate of change of flow and pressure, compensated mass balance, statistical, real-time transient modeling, acoustic wave sensing, fiber optic cable (distributed temperature, DAS), and subsea hydrophones. The paper described related credibility, deployment, organizational, and maintenance issues with an emphasis on upstream applications. The scope includes leak detection for pipelines conveying various flowing fluids— gas, liquid, and multiphase flow. Pipeline environments include subsea and onshore. Advantages, disadvantages, and experiences with these techniques will be described and analyzed. Various performance criteria are considered for comparison, such as system operational cost, sensitivity, accuracy, leak localization, system mode of operation, ease of usage, leak size estimation, ease of retrofitting, and false alarm rate. The analysis is performed using two and three-level performance comparisons. In the three-level analysis comparison, the operational cost, sensitivity, and false alarm rate are compared in the range of low, medium, and high. Fig. 6.45 shows a bar chart representing the three-level analysis of the reviewed methods based on their unique strengths and weaknesses. Leakage detection and localization in pipelines has become an important aspect of water management systems. Since monitoring leakage in large-scale water distribution networks (WDNs) is a challenging task, the need to develop a reliable and robust leak detection and localization technique is essential for loss reduction in potable WDNs. In this chapter, some of the existing techniques for water leakage detection are discussed and Operational cost Sensitivity Detection promptness False alarm High

Medium

Low

0 Acoustic

Fiber optic

IRT

GPR

Mass balance

NPW

Vapour samp.

PPA

Pipeline leakage detection methods FIGURE 6.45 Three level performance analysis comparison.

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open research areas and challenges are highlighted. It is concluded that despite the numerous research efforts and advancement in leakage detection technologies, a large scope is still open for further research in this domain. One such area is the effective detection of background type leakages that have not been covered fully in the literature. The utilization of wireless sensor networks for leakage detection purposes, the technical challenges, as well as some future research areas are also presented. The practical application of these techniques for large-scale water distribution networks is still a major concern. In this chapter, an overview of this important problem is addressed. As shown in Fig. 6.10, most of the techniques have high operational cost except NPW and vapor sampling. However, the high rate of false alarms is the major weakness of these two methods. In general, all methods perform well in terms of sensitivity, except IRT, GPR, and NPW. The rate of false alarms in most of the techniques such as acoustic emission, NPW, vapor sampling, dynamic modeling and DSP are high. Though many researchers have been working on alleviating these drawbacks, reducing false alarms in acoustic emission and DSP appears to be a challenging task as acoustic emissions are highly sensitive to random ambient noise and the DSP approach mainly depends on instrument calibration accuracy. Besides, different circumstances such as pipeline corrosion, bending and blockage can easily lead to false alarms in DSP. Among all the reviewed methods, the dynamic modeling method shows high sensitivity in detecting the presence of pipeline leakages. However, the high complexity of the mathematical models involved and strict experienced personnel requirements are the key challenges of this method. With the help of recent advances in high-performance computing and cloud computing technologies, the dynamic modeling approach will become more and more popular in the oil and gas industry. Table 6.13 shows a summary of the comparison, showing that none of the methods satisfies all attributes as they all vary in merits and critical shortcomings. For example, the systems based on infrared thermography are proven to be better in terms of system accuracy, leak localization, easy usage, and easy retrofitting, however, estimation of the leakage rate is difficult with this method. Similarly, almost all methods satisfy the ease of retrofitting or upgrading criterion except the fiber optic sensing method, where a point of breakage can lead to total system failure thereby requiring total sensor network replacement. System accuracy is also an important criterion to evaluate the performance of a pipeline leak detection system. Although some of the methods perform better with regards to this criterion, system detection capability also depends on other factors such as instrument calibration, and the quality and quantity of the instruments used.

6.5 Guideline for pipeline leakage detection method selection Since monitoring leakage in large-scale water distribution networks (WDNs) is a challenging task, the need to develop a reliable and robust leak detection and localization technique is essential for loss reduction in potable WDNs. Adedeji et al. (2017) discussed some of the existing techniques for water leakage detection. They concluded that despite the numerous research efforts and the advancement in leakage detection technologies, a large scope is still open for further research in this domain. One such area is the effective

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TABLE 6.13

Two-level performance analysis comparison. Performance comparison metric Leak Leak size Ease of localization estimation usage

Ease of Operational retrofitting mode

Methods

System accuracy

Acoustic emission

High, but sensitive to random Yes noise

No

Yes

Yes




Fiber optic sensing

High

Yes

Yes

Yes

No




Vapor sampling

Depends on sensing tube closeness to spilled gas

No

No

Yes

Yes




Infrared High thermography

Yes

No

Yes

Yes




Ground penetration radar

Low

Yes

No

Yes

Yes




Fluorescence

Low

No

No

No

Yes




Capacitive sensing

Low

No

N

Yes

Yes




Mass-volume Balance

Low, depends on instrument calibration and leak size

No

Yes

Yes

Yes

Steady state

Negative pressure wave

Low

Yes

No

Yes

Yes

Steady state

Pressure Low point analysis

Yes

Yes

Yes

Yes

Steady state

Digital signal Depends on leakage size and processing sensor used

Yes

No

Yes

Yes

Stead state

Yes

Yes

No

Yes

Both steady and transient state

Dynamic modeling

High, depends on pipeline stability and mathematical model

detection of background type leakages that have not been covered fully in the literature. The utilization of wireless sensor networks for leakage detection purposes, the technical challenges, as well as some future research areas were also presented. In general the practical application of these techniques for large-scale water distribution networks is still a major concern. As mentioned in the previous sections, there are various methods and mechanisms for pipeline leak detection and localization. However, the applicability of each method varies considerably depending on the pipeline operating conditions, pipeline characteristics, and the medium to be detected. For instance, detection of leakages in surface, underground, or

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TABLE 6.14 Summary of the guidelines for method selection. Methods

Operating environment

Sensor coverage

Hydrocarbon fluids

Acoustic sensing

All

Local

All

Fiber optic sensing

All

Local

All

Vapor sampling

Subsea

Local

All

Infrared thermography

All

Local

Oil and gas

Ground penetration radar

Underground

Local

Water and gas

Fluorescence

All

Local

Oil

Capacitive sensing

Subsea

Local

All

Spectral scanner

Surface

Local

Oil

Lidar system

Subsea

Local

All

Electromagnetic reflection

Surface

Local

Oil

Biological methods

Subsea

Local

All

Interior methods

All

Area

All

subsea environments can be attained through the use of approaches such as fiber optic cable, fluorescence, and interior methods. Whereas GPR can only be applied to underground pipeline networks. Some methods are applicable for all types of hydrocarbon fluid—including oil and gas—and water. However, only specific types of hydrocarbon fluid can be detected by some methods. In order to provide guidelines for selecting a method appropriate for a particular scenario, Table 6.14 lists the major available leak detection techniques and guidelines for their selection. The information is based on review works in the literature and information provided by the Joint Industry and Project (JIP) offshore leak detection report (Martini et al., 2017). “Local coverage” refers to the small area within the vicinity of the sensor. While “Area coverage” means that sensors can cover a large area but not provide entire field coverage. This study concerns the early detection of leaks occurring in small-diameter customers’ connections to water supply networks. An experimental campaign was carried out in a testbed to investigate the sensitivity of acoustic emission (AE) monitoring to water leaks. Damage was artificially induced on a polyethylene pipe (length 28 m, outer diameter 32 mm) at different distances from an AE transducer. Measurements were performed in both unburied and buried pipe conditions. The analysis permitted the identification of a clear correlation between three monitored parameters (namely total hits, cumulative counts and cumulative amplitude) and the characteristics of the examined leaks.

6.6 Research gaps and open issues Based on the various reviewed pipeline leak detection methods, research gaps and future research directions are identified in this section. The performance of pipeline

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leakage detection methods generally varies depending on the approaches, operational conditions, and pipeline networks. However, guidelines set by American Petroleum Institute (API 1555), such as sensitivity, accuracy, reliability, and adaptability, must be met before we can consider any leak detection system suitable for production solutions. Moreover, leak localization and estimation of the leakage rate are also important as they will facilitate spillage containment and maintenance at an early stage to avoid serious damage to the environment. The simplest way to achieve this goal is through deployment of a vast number of leak detection sensors in a sensor network between the upstream and downstream of the pipeline. By doing so, it will make it easy to isolate the leak position and thus improve the ability to track when a sensor acquires anomalous information at the expense of high implementation cost. Remote monitoring of oil and gas pipeline networks using wireless communications technology provide benefits of low cost, fast response, and the ability to track the locations where leakages occur. However, to attain benchmark performance in monitoring pipelines remotely some of the design issues that require research attention include sensing modality, sensing coverage, and leak localization. As mentioned in the previous sections, several sensors are designed for monitoring pipeline leakages using different sensing modalities. Usually, sensors are deployed for monitoring steady-state conditions where the physical pipeline context is expected to remain stable over time. Variations in physical parameters of the pipeline operation such as vibration, temperature, pressure, etc. are expected to be detectable and communicated to reveal the incidences of anomalies. Leaks can only be accurately detected if the incident is within the vicinity of the monitoring sensor and thus the accuracy of leak detection systems becomes questionable if the leaks are not within the receptive fields of the sensors. Sensors deployed for remote monitoring of pipelines are employed to perform both sensing and communication functions, however, the challenge of how to cover a monitoring region efficiently and to relay the obtained measurements to their neighboring nodes is also challenging in wireless sensor networks (WSNs), the impacts of which can be severe of network performance. There are many issues in designing optimal WSNs, particularly for pipeline monitoring. These issues include: (1) selforganization, (2) fault-tolerance, (3) optimal sensor node placement, (4) sensor coverage, (5) energy saving routing, (6) energy harvesting, and so on. During the lifetime of the sensor network some of the deployed sensor nodes are expected to experience hardware failure and the network may not be able to cope with this failure. This will limit the effectiveness of the whole network. The operation and performance of WSNs is largely dependent on optimal node placement as communication among the sensor nodes is required to transmit the acquired data. Besides, sensor placement also influences the resources management such as energy consumption in WSNs, while the energy consumption influences the network lifetime. Wireless sensor networks have the potential to revolutionize our everyday life, as they provide a flexible approach for us to observe the surrounding environment, and respond to events. The availability of tiny battery-powered sensor nodes, embedded with sensing, processing, and communication capabilities, wirelessly networked together via multihop communication, increase the opportunities for WSNs to find applications in a wide range of areas. Along with the opportunities, there are also challenges and requirements for the successful deployment and operations of WSNs. For example, sensor placement in pipeline

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monitoring requires careful considerations (Dhillon and Chakrabarty, 2003). The development of self-organization strategies has become an important research issue in WSNs. Sensor nodes are smart enough to autonomously reorganize themselves to share sensing and data transmission tasks when some nodes fail. The issue of coverage problems has been addressed in the literature (Li et al., 2009), giving an overview of WSN connectivity and discussing existing work that focuses on the connectivity issues in WSNs. In particular, the focus is on maintaining connected WSNs and their connectivity-related characteristics including sensor node placement, as well as the construction of a small connected relay set in WSNs. Ensuring the connectivity of a WSN is challenging when sensors have random locations, either because of mobility or initial random deployment. A substantial body of literature has been written on this problem, including deep theoretical results applied to simple models of i.i.d. uniformly distributed nodes with circular radio footprints. This model is widely accepted as it is analytically tractable. An important open research problem is to generalize these results to more realistic propagation models, including effects such as shadowing and nonuniform distribution of nodes, and to determine what engineering insights can be drawn from the theoretical asymptotic results. Connected subsets of nodes also play an important role in WSNs. As we have seen, cluster routing uses a connected “backbone” of nodes to simplify routing, and minimize the work required from the majority of sensor nodes. Finding the smallest such backbone is equivalent to finding a Minimum Connected Dominating Set in the corresponding graph, which is known to be NP-complete. Further research is needed both into finding more efficient, more accurate, or simpler suboptimal solutions to the MCDS problem, and also into the benefits which can be obtained by using nonminimum backbones. Such benefits include reduced path lengths, and increased resilience. Such research will play an important part in bringing about the benefits that sensor networks have to offer. The future lies within modeling signals with nonlinear filters (Islam et al., 2016). Since a high percentage of pipeline systems are made up of underground and underwater pipelines networks and the power required for real-time sensing and data communications in such environments is demanding, better replacement of sensor nodes in these settings is expensive or infeasible for large sensor networks. This comes with an increasingly more complex and hence nonlinear configuration. In the past the focus has been on minimizing energy constraints in order to achieve long-lived networks in these energy constrained environments, for example, different energy consumption minimization methods, such as low energy adaptive clustering hierarchy. Various algorithms have been developed to minimize the energy consumption of sensor nodes in WSN. Among them, low-energy adaptive clustering hierarchy (LEACH) is considered to be more efficient. Prabhu and Sophia (2013) compared the energy-efficient optical LEACH algorithm with the existing LEACH algorithm in two wireless sensor network fields. The comparison was based on the parameters of data rate and network lifetime. To overcome the drawbacks of optical fiber sensor (OFS) link, a few concepts were investigated. In a WSN, sensor nodes are strictly energy and capacity constrained, which makes it necessary for them to collaboratively execute a complex task (Tian and Ekici, 2007). Thus, task allocation becomes a fundamental and crucial issue in WSNs. Most previous studies developed centralized methods to solve this problem. In addition, a common assumption is that all the sensor nodes are homogeneous, which is unfavorable in many real

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applications. A distributed task allocation strategy which can handle the problem in a heterogeneous wireless sensor network was proposed. The task was propagated from nodes to nodes and each node matches its own capacity with the required capacities until all the demanded capacities of the task were obtained. Building on this, an enhanced task allocation strategy based on self-organization was developed. By utilizing previous assigning information, the nodes with proper capacities were selected as candidate nodes, then the paths to these nodes were optimized by Yin et al. (2017). In so doing, a new arriving task could be allocated directly and quickly. Simulation results showed the feasibility of the proposed approach. Furthermore, the overall performance of the self-organization-based strategy was validated through a comparison with a particle swarm optimization-based centralized method and the fundamental method. Energy can also be harvested from the resources in the pipeline surroundings such as fluid flow, pipe vibration, pressure, and water kinetics using piezoelectric transducers. Although great improvements have been observed in the research and development of wireless sensor network technology, efficient and reliable energy storage and generic plug and play energy harvesters from multiple sources remain open research challenges. Leak localization is very essential in pipeline monitoring as it will speed up the repair process. Different methods of defect localization in pipelines have been proposed. The performance of these techniques, however, varies in terms of accuracy, degree of complexity, and operation environments. Mobile sensor nodes with built-in Global Positioning System (GPS) have been successfully deployed to determine and report the geographical location of pipeline leakages. The use of mobile sensor nodes in pipeline environments is essential as it can enhance coverage and recover the network from any failure which partitions the whole network into multiple disconnected subnetworks. However, the cost of implementation of these sensor nodes with GPS capability is extremely high. Besides, it may be difficult for the GPS signals to penetrate the metal or concrete walls which protect pipelines. If all sensor nodes are static, their locations are marked using GPS and stored permanently in a map in the deployment phase. Leaks can then be localized based on the known locations of reporting sensor nodes. On the contrary, scalability of the pipeline leakage detection sensor network is another research challenge when the coverage of the pipeline network is huge. In this regard, localization techniques with satisfactory performance will be a welcome addition to the leak detection mechanism toolbox. Temperature variation is a common type of environmental uncertainty that affects the accuracy of flow monitoring systems significantly. Environmental uncertainties can affect the properties of fluids in pipelines such as fluid density, viscosity, friction factor, etc. Although some studies have provided insights for the development of temperaturedependent flow models (Delgado-Aguinaga et al., 2016), these investigations are only limited to short flow models in which spatial changes of the temperature can be neglected. In Delgado-Aguinaga et al. (2016), the problem of robustness to temperature variations in pipeline leak detection and isolation is considered, extending preliminary attempts in this direction. The approach is restricted to pipelines short enough that the spatial variations of the temperature can be neglected, and only time variations are addressed. The methodology is based on a model taking into account the variations in all the parameters subject to temperature changes, like friction factor, water density, etc. A temperature measurement is then used to compensate for such variations in an Extended Kalman Filter used as

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a state observer, and real-time experimental tests are provided showing how an accurate leak identification is achieved when this compensation is done, while it fails otherwise. A robust temperature variation compensation approach will provide additional advantages for fluid flow modeling. It is important to detect the valid leaks and reduce the number of false positive alarms so that pipeline leak detectors can attain acceptable accuracy. All leakage detectors are based on inference based on evidence acquired from sensors. The input evidence signature is usually noisy or error prone. The noise is in general random in nature and its underlying probability distribution is unknown. The source of the noise comes from inaccurate system measurements, instruments calibration, system modeling, data processing, feature extraction, and communications. For example, in an acoustic emission leak detection method the data acquired using acoustic sensors usually have inherent noise disruption and signal attenuation phenomena. In order to reduce the effect of this noise, certain design requirements for signal filtering must be met. The effectiveness of some of the signal filtering algorithms, such as Savitzky-Golay, Ensemble, and Applet (Henrie et al., 2016), can reduce the degree of signal distortion to acceptable level. An autonomous system that can detect, locate, and quantify the rate of leakage with the capability to manage a large amount of acquired data is essential for planned and unplanned leak incidents. Advanced data visualization tools will definitely help in showing the state of flow activities for decision-making in leak detection, localization and characterization, and pipeline maintenance. In addition, analysis of data-driven self-testing incidents and other offline performance validation methods will also enhance the system flexibility. In general, the aim of future pipeline monitoring is to design a real-time intelligent pipeline leak detection and localization system for subsea pipeline networks. The effect of environmental factors, in particular, hydrodynamic forces due to oblique wave and current loading on subsea pipelines, still require further research study. Extensive simulation and laboratory experiments are being conducted to study the effects of leakage parameters, like size and shape, on the flow mechanism and validate different models. Numerical simulations of fluid flow in pipeline using computational fluid dynamics (CFD) have been proven to provide a better understanding of pipeline internal flow and the conditions of pipeline leaks on various scales, thereby reducing the cost in experimental studies. However, high computational complexity remains one of the major drawbacks of CFD. Further research efforts are still required to optimize and/or parallelize CFD solution algorithms in terms of computation and memory resource constraints. The weakest link in this narrative is the cow mutational methods that are used. They are invariably linearized and the future approach must include nonlinear solutions that produce a series of points rather than exact solutions.

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C H A P T E R

7 Storage of petroleum fluids 7.1 Introduction As in any commodity, there is always a discrepancy between supply and demand. In order to smooth out these discrepancies, storage of oil and natural gas is essential to petroleum operations. Companies store more when the prices are lower than they would like and withdraw when prices are high. This is equivalent to hoarding and has limitations. The discrepancy between supply and demand depends on oil price, which is a function of many factors, including politics. The Brent crude oil spot price averaged $105 per barrel (b) in April, a $13/b decrease from March. Although down from March, crude oil prices remain above $100/b following Russia’s full-scale invasion of Ukraine. Sanctions on Russia and other independent corporate actions contributed to falling oil production in Russia and continue to create significant market uncertainties about the potential for further oil supply disruptions. These events occurred against a backdrop of low oil inventories and persistent upward oil price pressures. Global oil inventory draws averaged 1.7 million barrels per day (b/d) from the third quarter of 2020 (3Q20) through the end of 2021. EIA (2022a
c) estimates that commercial oil inventories in the OECD ended 1Q22 at 2.63 billion barrels, upslightly from February, which was the lowest level since April 2014. It is expected that the Brent price will average $107/b in 2Q22 and $103/b in the second half of 2022 (2H22). It is projected that the average price will fall to $97/b in 2023. These outcomes, however, depend on the degree to which existing sanctions imposed on Russia, any potential future sanctions, and independent corporate actions affect Russia’s oil production or the sale of Russia’s oil in the global market. Also can affect any EU ban on Russia and the ability of Russia to cope with sanctions, particularly in competition with US dollar-driven global energy trade. In addition, the degree to which other oil producers respond to current oil prices and the effects, macroeconomic developments might have on global oil demand will be important for oil price formation in the coming months. EIA (2022a
c) estimates that 97.4 million b/d of petroleum and liquid fuels were consumed globally in April 2022, an increase of 2.1 million b/d from April 2021. They forecast that global consumption of petroleum and liquid fuels will average 99.6 million b/d for all of 2022, which is a 2.2 million b/d increase from 2021. This is revised down our forecast for 2022 global consumption of petroleum and liquid fuels by 0.2 million b/d from the April STEO, primarily as a result of downward revisions to consumption growth in China

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and the United States. It is forecasted that global consumption of petroleum and liquid fuels will increase by 1.9 million b/d in 2023 to an average of 101.5 million b/d. Fig. 7.1 shows the supply and demand discrepancy history in recent years. In general, the discrepancy has been contained within manageable storage needs (Figs. 7.2
7.5). OPEC countries maintain a stable surplus capacity (Fig. 7.6). Table 7.1 lists the history and future projection of oil storage for different locations (Fig. 7.7).

FIGURE 7.1 World liquid fuel balance in recent years (EIA, 2022a
c).

FIGURE 7.2 Monthly history of liquid fuel consumption (EIA, 2022a
c).

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FIGURE 7.3 Annual change history in various geographical areas.

FIGURE 7.4 Short-time energy outlook.

At present, there is a total of 3.4 billion barrels of crude oil storage that was in use worldwide as of March 2020 (So¨nnichsen, 2021). Only 0.5 billion barrels of crude oil storage was available across the United States as of the same time, the majority of which was available in tanks. Table 7.2 lists the distribution of global petroleum storage. The cheapest storage method is underground spaces, such as depleted reservoirs. This method is primarily used for natural gas; finished oil products cannot be stored in

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FIGURE 7.5 OPEC countries’ surplus production capacity.

FIGURE 7.6 OECD countries’ commercial inventories.

underground natural spaces per regulations. Above-ground tanks are used for crude and refined oil, finished oil products, and natural gas. At retail locations, like gas stations, tanks are stored underground for safety reasons. Tanker ships are used for temporary storage when land storage is at capacity, making it the most expensive option (Downy, 2009). There is a minimum operating level of crude oil that cannot be removed from pipelines, refinery tanks, and overall system without difficulties (Downy, 2009). In 2020, the coronavirus

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TABLE 7.1 World oil demand and supply (mb/d). 2019

1Q20

2Q20

3Q20

4Q20

2020

1Q21

2Q21

3Q21

4Q21

2021

2022

2023

2024

2025

2026

47.7

45.4

37.6

42.3

43.1

42.1

43.3

43.8

45.4

46.5

44.7

45.8

46.2

46.2

46.0

45.8

52.0

48.3

45.3

50.4

51.7

48.9

50.7

51.1

52.3

52.7

51.7

53.7

55.0

56.1

57.2

58.3

99.7

93.8

82.9

92.7

94.7

91.0

93.9

94.9

97.7

99.2

96.5

99.4

101.2

102.3

103.2

104.1

28.5

29.9

26.9

27.1

27.8

27.9

27.8

28.1

28.3

28.7

28.2

29.0

29.6

29.9

29.9

29.7

32.0

32.3

30.0

29.7

29.9

30.5

30.3

30.8

30.8

30.7

30.6

31.5

32.0

32.0

32.1

32.1

2.4

2.3

2.0

2.1

2.1

2.1

2.1

2.2

2.3

2.3

2.2

2.4

2.4

2.4

2.5

2.5

2.8

2.2

2.5

3.1

2.6

2.6

2.3

2.9

3.2

2.9

2.8

3.0

3.1

3.2

3.3

3.3

65.6

66.7

61.3

61.9

62.4

63.1

62.5

63.9

64.5

64.6

63.9

66.0

67.1

67.5

67.7

67.6

29.5

28.2

25.6

24.1

24.9

25.7

5.4

5.4

5.2

5.1

5.2

5.2

5.2

5.3

5.3

5.3

5.3

5.5

5.5

5.6

5.6

5.7

34.9

33.6

30.8

29.2

30.0

30.9

100.5

100.2

92.1

91.1

92.4

93.9

28.7

21.7

16.4

25.7

27.2

22.8

26.2

25.7

27.9

29.3

27.3

28.0

28.6

29.2

29.9

30.8

DEMAND Total OECD Total Non-OECD a

Total demand Supply Total OECD

Total Non-OECD b

Processing gains Global biofuels

Total Non-OPEC

c

OPEC Crude OPEC NGLs Total OPEC

c

Total supply Memo items: Call on OPEC crude 1 Stock ch.d

a Measured as deliveries from refineries and primary stocks, which comprises inland deliveries, international marine bunkers, refinery fuel, crude for direct burning, oil from nonconventional sources, and other sources of supply. b Net volumetric gains and losses in the refining process and marine transportation losses. c Total Non-OPEC excludes all countries that are currently members of OPEC. Total OPEC comprises all countries which are current OPEC members. d Equals the arithmetic difference between total demand minus total non-OPEC supply minus OPEC NGLs.

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7. Storage of petroleum fluids

FIGURE 7.7 World production and consumption history for OPEC and OECD countries (EIA, 2022a
c). TABLE 7.2 Current world storage capacity (So¨nnichsen, 2021). Type of fluid

Type

Volume of storage

Crude oil

Currently used world storage

3.4 billion bbl

US strategic petroleum reserve

0.1 billion bbl

US tanks

0.3 billion bbl

US Refineries

0.1 billion bbl

China

0.4 billion bbl

Currently used world storage

2.5 billion bbl

US bulk terminal

0.6

US refineries

0.2

China

0.1

Oil products

pandemic dramatically reduced the demand for oil, which was coupled with an oversupply due to Saudi Arabia, increasing oil production and OPEC and non-OPEC countries failing to come to an agreement on reducing oil production (Paris, 2020). This meant storage tanks were near capacity. In response, oil storage companies drastically increased their storage rates. In one example, tankers were charging around $25,000 per day in February of 2020 but by April had risen rates to $300,000 per day (Downy, 2009).

7.1.1 US strategic petroleum reserve Governments require producers and refineries to carry larger storage than they would otherwise for security purposes. In some countries, like the United States, the government

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stores the oil reserves instead of a commercial company (https://guides.loc.gov/oil-andgas-industry/midstream/storage#note5). Emergency crude oil is stored in the US Strategic Petroleum Reserve (SPR) the world’s largest supply of emergency crude oil. These stocks are stored in huge underground salt caverns along the coastline of the Gulf of Mexico. The President, under the authority of the Energy Policy and Conservation Act (EPCA), can make the decision to withdraw crude oil. The need for a national reserve dates back to 1944 when Secretary of the Interior Harold Ickes advocated stockpiling emergency crude oil, but the idea was not put into practice until President Gerald Ford signed the EPCA in 1975 after the 1973
74 oil embargo intensified the need for a strategic oil reserve (EIA, 2015). The SPR is a US Government complex of four sites with deep underground storage caverns created in salt domes along the Texas and Louisiana Gulf Coasts. 7.1.1.1 Highest inventory The SPR was filled to its then 727 million barrel authorized storage capacity on December 27, 2009; the inventory of 726.6 million barrels was the highest ever held in the SPR. 7.1.1.2 Previous inventory milestones 1. 2008. Prior to Hurricane Gustav coming ashore on September 1, 2008, the SPR had reached 707.21 million barrels, the highest level ever held up until that date. A series of emergency exchanges conducted after Hurricane Gustav, followed shortly thereafter by Hurricane Ike, reduced the level by 5.4 million barrels. 2. 2005. Prior to the 2008 hurricane releases, the former record had been reached in late August 2005, just days before Hurricane Katrina hit the Gulf Coast. Hurricane Katrina emergency releases of both crude oil sales and exchanges (loans) totaled 20.8 million barrels. 3. 1977. First oil was delivered to the newly constructed SPR, 412,000 barrels of light sweet crude. 7.1.1.3 Crude oil inventory by site (as of May 4, 2022) 1. Bryan Mound contains 211.8 MMB in 18 caverns—66.8 MMB sweet and 145 MMB sour. 2. Big Hill contains 115.7 MMB in 14 caverns—65 MMB sweet and 50.7 MMB sour. 3. West Hackberry contains 167.2 MMB in 19 caverns—102.2 MMB sweet and 65 MMB sour. 4. Bayou Choctaw contains 50.7 MMB in 6 caverns—11 MMB sweet and 39.7MMB sour. 7.1.1.4 Current authorized storage capacity—714 million barrels The SPR completed fill on December 27, 2009, with a cargo that arrived and began to unload on Christmas Day. The cargo was 493,000 barrels of Saharan Blend, a light sweet crude that was delivered to the Bryan Mound site. A sale and drawdown in 2011 reduced the inventory to 695.9 million barrels. Current days of import protection in SPR. At the end of CY 2019 (as of December 31, 2019), the SPR’s crude oil inventory was 634.9 MMbbl. This is equivalent to approximately 1069 days of supply of total US petroleum net imports. International energy agency requirement. About 90 days of import protection (both public and private stocks). In past years, the United States has met its commitment with a

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combination of SPR stocks and industry stocks. The days of import protection may vary based on actual net US petroleum imports and the inventory level of the SPR. Average price paid for oil in the Reserve. $29.70 per barrel. 7.1.1.5 Drawdown capability 1. Maximum nominal drawdown capability. 4.4 million barrels per day. 2. Time for oil to enter the US market. 13 days from the Presidential decision. 7.1.1.6 Past sales 1. FY 2020 Mandated Sales. 9.85 million barrels 2. FY 2019 SPR Modernization Sale. 4.2 million barrels 3. FY 2019 Mandated Sales. 10.87 million barrels 4. FY 2018 SPR Modernization Sale. 4.74 million barrels 5. FY 2018 Mandated Sales. 14.17 million barrels 6. FY 2017 Mandated Sales. 10 million barrels 7. FY 2017 SPR Modernization Sale. 6.28 million barrels 8. 2014 March, Test Sale. 5 million barrels 9. 2011 June, IEA Coordinated Release. 30,640,000 barrels 10. 2005 September, Hurricane Katrina Sale. 11 million barrels 11. 1996
97 October, January, April, Total nonemergency sales. 28 million barrels 12. 1990
91 September, January, Desert Shield/Storm Sale. 21 million barrels (4 million in August 1990 test sale; 17 million in January 1991 Presidentially ordered drawdown) 13. 1985 November, Test Sale. 1.0 million barrels 7.1.1.7 Past exchanges 1. In August 2017, 5.2 million barrels of oil were exchanged following Hurricane Harvey, delivered to Gulf Coast refineries as a result of much of the Gulf region’s oil refining capabilities being shut down, resulting in fuel shortages. 2. In September 2012, 1 MMB was exchanged with Marathon Oil following Hurricane Isaac due to disruptions to the commercial oil production, refining, and distribution operations in the Gulf Coast. 3. In September
October 2008, two test exchanges were conducted following Hurricanes Gustav and Ike, totaling 5,389,000 barrels. Deliveries were made to Marathon, Placid, ConocoPhillips, Citgo, and Alon USA. 4. In June 2006, 750 thousand barrels of sour crude with ConocoPhillips and Citgo were exchanged due to the closure for several days of the Calcasieu Ship Channel to maritime traffic. The closure resulted from the release of a mixture of storm water and oil. Action was taken to avert temporary shutdown of both refineries. 5. In January 2006, 767 thousand barrels of sour crude with Total Petrochemicals USA were exchanged due to closure of the Sabine Neches ship channel to deep-draft vessels after a barge accident in the channel. Action was taken to avert temporary shutdown of the refinery. 6. In September
October 2005, 9.8 million barrels of sweet and sour crude were exchanged due to disruptions in Gulf of Mexico production and damage to terminals, pipelines, and refineries caused by Hurricane Katrina.

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7. In September
November 2004, 5.4 million barrels of sweet crude were exchanged due to disruptions in the Gulf of Mexico caused by Hurricane Ivan. 8. In October 2002, 98,000 barrels were exchanged with Shell Pipeline Co. to secure Capline storage tanks in advance of Hurricane Lili. 9. In September
October 2000, 30 million barrels were exchanged in response to concern over low distillate levels in Northeast. 10. In July
August 2000, 2.8 million barrels of crude oil were exchanged for first-year tank storage and stocks for 2 million barrel Northeast Home Heating Oil Reserve. 11. In June 2000, 500,000 barrels, each with CITGO and Conoco, were exchanged due to blockage of the ship channel that allowed incoming crude oil shipments to those refineries. Action taken in order to avert temporary shutdown of both refineries. 12. In August 1998, 11 million barrels of lower quality Maya crude in SPR were exchanged with PEMEX for 8.5 million of higher quality crude (more suitable for US refineries). 13. In April
May 1996, 900,000 barrels of SPR crude were exchanged with ARCO to resolve company’s pipeline blockage problem. Investment to date. About $25.7 billion ($5 billion for facilities; $20.7 billion for crude oil).

7.1.2 Natural gas storage Natural gas—a colorless, odorless, gaseous hydrocarbon—may be stored in a number of different ways. It is most commonly held in inventory underground under pressure in three types of facilities. These underground facilities are as follows: 1. depleted reservoirs in oil and/or natural gas fields; 2. aquifers; and 3. salt cavern formations. Natural gas is also stored in liquid or gaseous form in above-ground tanks. Each storage type has its own physical characteristics (porosity, permeability, retention, and capability) and economics (site preparation and maintenance costs, deliverability rates, and cycling capability), which govern its suitability for particular applications. Two important characteristics of an underground storage reservoir are its capacity to hold natural gas for future use and the rate at which gas inventory can be withdrawn—called its deliverability rate. Most existing natural gas storage in the United States is in depleted natural gas or oil fields that are close to consumption centers. Conversion of a field from production to storage duty takes advantage of existing wells, gathering systems, and pipeline connections. Depleted oil and natural gas reservoirs are the most commonly used underground storage sites because of their wide availability. When natural gas production is higher than natural gas consumption (typically April through October), it can be placed into storage. When natural gas production is lower than consumption (November through March), it can be withdrawn from storage to meet demand. About 20% of all natural gas consumed each winter comes from underground storage. Storage can also be used to keep natural gas flowing to customers in the event of

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FIGURE 7.8 Storage and withdrawal of natural gas during the year.

temporary disruptions in production and also helps interstate pipeline companies balance system supply on their long-haul transmission lines. The flexibility and resiliency provided by storage are keys to maintaining reliable and responsive natural gas delivery, as shown in Fig. 7.8. In United States, there are approximately 400 active storage facilities in 30 states. Approximately, 20% of all natural gas consumed during the 5-month winter heating season each year are supplied by underground storage. There are three principal types of underground storage sites used in the United States today: depleted natural gas or oil fields (80%), aquifers (10%), and salt formations (10%). Underground storage working natural gas capacity in the United States increased by 18.2% between 2002 and 2014, helping to ensure that natural gas is available when it is needed most. Approximately, 4 trillion cubic feet of natural gas can be stored and withdrawn for consumer use. Working gas in storage was 2401 Bcf as of Friday, July 15, 2022, according to EIA estimates. This represents a net increase of 32 Bcf from the previous week. Stocks were 270 Bcf less than last year at this time and 328 Bcf below the 5-year average of 2,729 Bcf. At 2401 Bcf, total working gas is within the 5-year historical range (Fig. 7.9). Natural gas is stored underground primarily in three reservoir types: depleted oil and natural gas fields, salt formations, and depleted aquifers. Natural gas may also be stored above ground in refrigerated tanks as liquefied natural gas (LNG) (Fig. 7.10). Of the approximately 400 active underground storage facilities in the United States, about 79% are depleted natural gas or oil fields. Conversion of an oil or natural gas field from production to storage takes advantage of existing wells, gathering systems, and pipeline connections. Depleted oil and natural gas reservoirs are the most commonly used underground storage sites because of their wide availability.

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507

FIGURE 7.9 Underground storage and withdrawal in United States (EIA, 2022a). Note: The shaded area indicates the range between the historical minimum and maximum values for the weekly series from 2017 through 2021. The dashed vertical lines indicate current and year-ago weekly periods.

FIGURE 7.10 Schematic of natural gas storage sites.

Pipelines

508

7. Storage of petroleum fluids

Salt formation storage facilities (also known as caverns and beds) make up about 11% of all facilities. These subsurface salt formations are primarily located in the Gulf Coast states. Salt formations provide very high withdrawal and injection rates. Natural aquifers may be suitable for natural gas storage if the water-bearing sedimentary rock formation is overlaid with an impermeable cap rock. They are not part of drinking water aquifers and makeup only about 10% of storage facilities (Fig. 7.11). The owners/operators of underground storage facilities are primarily interstate pipeline companies, intrastate pipeline companies, local distribution companies (LDCs), and independent storage service providers. About 120 entities currently operate underground storage facilities in the United States, approximately half of which are interstate and half intrastate. Underground natural gas storage operators are committed to ensuring the safety and integrity of their facilities. The industry’s construction, operation, and integrity management protocols are overseen by multiple agencies at the state and federal levels with jurisdiction over underground storage facilities: 1. The Federal Energy Regulatory Commission (FERC) regulates projects connected to interstate pipeline systems. FERC is responsible for authorizing the construction or expansion of storage facilities and the terms and conditions of service (i.e., open access) and the rates charged by these providers. 2. The Pipeline and Hazardous Materials Safety Administration is authorized to regulate the safety of natural gas transportation and storage. 3. Intrastate storage may fall under the regulatory authority of various state government entities depending upon the state. For example, underground storage in Texas is under

FIGURE 7.11

Various storage sites in United States.

Pipelines

7.1 Introduction

509

the authority of the TX Railroad Commission-Oil & Gas Division. Often state utility commissions as well as state environmental or natural resource agencies set the rules governing intrastate underground storage. 4. Beyond federal and state regulation, industry has taken the initiative to work with external stakeholders to develop two recommended practices (RPs)—accredited by the American National Standards Institute—for underground storage. RP 1170 and 1171 provide guidance to operators on how to design, operate, and ensure the integrity of underground storage for natural gas. Well Integrity Practices for Underground Storage of Natural Gas Given the geographic and geologic diversity in storage operations in North America, no single integrity management approach and no single integrity verification technique are applicable or adequate for each and every storage well. Below are some of the common well integrity assessment methods used within the industry to protect their assets and the public’s best interests. Storage operators check for weak points and leakage, and investigate suspicious indications through a variety of downhole logging techniques, including formation evaluation tools (e.g., neutron logging), fluid movement indicators (noise and temperature surveys), casing inspections (magnetic flux leakage and ultrasonic methods), mechanical calipers, downhole cameras, and cathodic protection profile surveys. Operators use multiple methods to make decisions on the mitigation and maintenance work that must be done to help ensure the integrity of the well. With increasing data, data analysis, and recognition of the integrity drivers, operators are using risk-based assessments to drive their underground storage well integrity management programs. API RP 1170 and 1171 provide more technical information on assessment and monitoring methods. In addition to tool-based assessment methods, the industry uses pressure tests and pressure monitoring as integrity assessment methods. Common approaches used by operators include shut-in pressure monitoring, annulus pressure or flow monitoring, and mechanical integrity tests at the well. In some areas, most notably the midwestern United States, natural aquifers have been converted to natural gas storage reservoirs. An aquifer is suitable for gas storage if the waterbearing sedimentary rock formation is overlaid with an impermeable cap rock. Although the geology of aquifers is similar to depleted production fields, their use for natural gas storage usually requires more base (cushion) gas and allows less flexibility in injecting and withdrawing. Deliverability rates may be enhanced by the presence of an active water drive, which supports the reservoir pressure through the injection and production cycles. Salt caverns provide very high withdrawal and injection rates relative to their working gas capacity. Base gas requirements are relatively low. Most salt cavern storage facilities have been developed in salt dome formations located in the Gulf Coast states. Salt caverns have also been made (by a process called leaching) in bedded salt formations in Northeastern, Midwestern, and Southwestern states. Cavern construction is more costly than depleted field conversions when measured on the basis of dollars per thousand cubic feet of working gas capacity, but the ability to perform several withdrawal and injection cycles each year reduces the per-unit cost of each thousand cubic feet of gas injected and withdrawn.

Pipelines

510

7. Storage of petroleum fluids

The principal owners/operators of underground storage facilities are interstate pipeline companies, intrastate pipeline companies, LDCs, and independent storage service providers. About 120 entities currently operate the nearly 400 active underground storage facilities in the lower 48 states. If a storage facility serves interstate commerce, it is subject to the jurisdiction of the FERC; otherwise, it is state regulated. Fig. 7.12 shows a stylized representation of the various types of underground storage facilities. Fig. 7.13 shows the US natural gas storage regions. Owners/operators of storage facilities are not necessarily the owners of the natural gas held in storage. In fact, most working gas held in storage facilities is held underlease with shippers, LDCs, or end users who own the gas. The type of entity that owns/operates the facility will determine to some extent how that facility’s storage capacity is utilized. For example, interstate pipeline companies rely heavily on underground storage to facilitate load balancing and system supply management on their long-haul transmission lines.

FIGURE 7.12 Types of gas storage. Source: From EIA, 2015. The Basics of Underground Natural Gas Storage, November 16.

Pipelines

7.2 Oil storage

511

FIGURE 7.13 Gas storage sites in United States. Source: From EIA, 2015. The Basics of Underground Natural Gas Storage, November 16.

FERC regulations allow interstate pipeline companies to reserve some portion of their storage capacity for this purpose. Nonetheless, the bulk of their storage capacity is leased to other industry participants. Intrastate pipeline companies also use storage capacity and inventories for similar purposes, in addition to serving customers.

7.2 Oil storage Oil storage tanks are used to store crude oil as well as processed or refined oil. Oil storage tanks are an inherent part of oil production as each field must have an oil storage facility. Storage tanks are necessary to hold crude oil after separation and before refining. Storage tanks contain organic liquids, nonorganic liquids, and vapors and can be found in many industries. Most storage tanks are designed and built to the American Petroleum Institute (API) 650 specification. These tanks can have different sizes, ranging from 2 to 60 m in diameter or more. They are generally installed inside containment basins in order to contain spills in case of rupture of the tank. There are eight types of tanks used to store liquids: 1. Fixed-roof tanks.

Pipelines

512 2. 3. 4. 5. 6. 7. 8.

7. Storage of petroleum fluids

External floating roof tanks. Internal floating roof tanks. Domed external floating roof tanks. Horizontal tanks. Pressure tanks. Variable vapor space tanks. LNG tanks.

7.2.1 Fixed-roof tank The first four tank types are cylindrical in shape with the axis oriented perpendicular to the subgrade. These tanks are almost exclusively above ground. Horizontal tanks can be used above and below ground. Pressure tanks often are horizontally oriented and spherically shaped to maintain structural integrity at high pressures. They are located above ground. Variable vapor space tanks can be cylindrical or spherical in shape (Picture 7.1). A containment basin of a product should be built around the tanks that are made of brick or concrete and the lining should be impervious to liquid stored to prevent spills that can cause fire, property damage, or contaminate the environment. The minimum capacity of the basin volume should be equal to the capacity of the largest tank plus 10% of the sum of the capacities of others. To prevent a spill or other emergency, the walls of the containment basin must be resistant to the product and must be able to withstand considerable pressure. The drain valve, which should be incorporated into the outer side of the containment basin, must be closed to prevent possible contamination to the environment. Of currently used tank designs, the fixed-roof tank is the least expensive to construct and is generally considered the minimum acceptable equipment for storing liquids. A typical fixed-roof tank consists of a cylindrical steel shell with a cone- or dome-shaped roof that is permanently affixed to the tank shell. Storage tanks are usually fully welded and designed for both liquid and vapor tight, while older tanks are often have a riveted or bolted construction and are not vapor tight.

PICTURE 7.1 Primafuel, tank farm (website 5).

Pipelines

513

7.2 Oil storage

A breather valve (pressure-vacuum valve), which is commonly installed on many fixedroof tanks, allows the tank to operate at a slight internal pressure or vacuum (Picture 7.2). This valve prevents the release of vapors during only very small changes in temperature, barometric pressure, or liquid level, and the emissions from a fixed-roof tank can be appreciable. Additionally, gage hatches/sample wells, float gauges, and roof manholes provide accessibility to these tanks and also serve as potential sources of volatile emissions (Picture 7.3).

PICTURE 7.2

Breather valve.

PICTURE 7.3 Larger image lifting and handling of a stainless steel storage tank.

Pipelines

514

7. Storage of petroleum fluids

7.2.2 External floating roof tank A typical external floating roof tank consists of an open-topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid, rising and falling with the liquid level. The floating roof is comprised of a deck, fittings, and rim seal system. Floating roof decks are constructed of welded steel plates and are of three general types: pan, pontoon, and double deck. Although numerous pan-type decks are currently in use, the present trend is toward pontoon and double-deck type floating roofs. Manufacturers supply various versions of these basic types of floating decks, which are tailored to emphasize particular features, such as full liquid contact, load-carrying capacity, roof stability, or pontoon arrangement. The liquid surface is covered by the floating deck, except in the small annular space between the deck and the shell; the deck may contact the liquid or float directly above the surface on pontoons. External floating roof tanks are equipped with a rim seal system, which is attached to the roof perimeter and contacts the tank wall. The rim seal system slides against the tank wall as the roof is raised and lowered. The floating deck is also equipped with fittings that penetrate the deck and serve operational functions. The external floating roof design is such that evaporative losses from the stored liquid are limited to losses from the rim seal system and deck fittings (standing storage loss) and any exposed liquid on the tank walls (withdrawal loss).

7.2.3 Internal floating roof tank Those tanks have both, a permanent fixed roof and a floating roof inside. There are two basic types of internal floating roof tanks: 1. Tanks in which the fixed roof is supported by vertical columns within the tank. 2. Tanks with a self-supporting fixed roof and no internal support columns. The fixed roof is not necessarily free of openings but does span the entire open-plan area of the vessel. Fixed roof tanks that have been retrofitted to employ an internal floating roof are typically of the first type, while external floating roof tanks that have been converted to an internal floating roof tank typically have a self-supporting roof. Tanks initially constructed with both a fixed roof and an internal floating roof may be of either type. An internal floating roof tank has both a permanently affixed roof and a roof that floats inside the tank on the liquid surface (contact deck) or is supported on pontoons several inches above the liquid surface (noncontact deck). The internal floating roof rises and falls with the liquid level.

7.2.4 Domed external floating roof tank Domed external floating roof tanks have the heavier type of deck used in external floating roof tanks as well as a fixed roof at the top of the shell like internal floating roof tanks. Domed external floating roof tanks usually result from retrofitting an external floating roof tank with a fixed roof. As with the internal floating roof tanks, the function of the fixed roof is not to act as a vapor barrier but to block the wind. The type of fixed roof

Pipelines

7.2 Oil storage

515

most commonly used is a self-supporting aluminum dome roof, which is of bolted construction. Like the internal floating roof tanks, these tanks are freely vented by circulation vents at the top of the fixed roof. The deck fittings and rim seals, however, are basically identical to those on external floating roof tanks.

7.2.5 Horizontal tank Horizontal tanks are constructed for both above-ground and underground service. Horizontal tanks are usually constructed of steel, steel with a fiberglass overlay, or fiberglassreinforced polyester. Horizontal tanks are generally small storage tanks. Horizontal tanks are constructed such that the length of the tank is not greater than six times the diameter to ensure structural integrity. Horizontal tanks are usually equipped with pressure-vacuum vents, gage hatches and sample wells, and manholes to provide accessibility to these tanks. In addition, underground tanks may be cathodically protected to prevent corrosion of the tank shell. Cathodic protection is accomplished by placing sacrificial anodes in the tank that are connected to an impressed current system or by using galvanic anodes in the tank. However, internal cathodic protection is no longer widely used in the petroleum industry, due to corrosion inhibitors that are now found in most refined petroleum products.

7.2.6 Pressure tank According to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Code Section VIII, pressure vessels are containers for the containment of pressure, either internal or external. This pressure may be obtained from an external source or by the application of heat from a direct or indirect source as a result of a process, or any combination thereof. The ASME Code is the construction code for pressure vessels and contains mandatory requirements, specific prohibitions, and nonmandatory guidance for pressure vessel materials, design, fabrication, examination, inspection, testing, and certification. Pressure vessels can theoretically be almost any shape, but shapes made of sections of spheres, cylinders, and cones are usually employed. A common design is a cylinder with end caps called heads. Head shapes are frequently either hemispherical or dished (torispherical). More complicated shapes have historically been much harder to analyze for safe operation and are usually far more difficult to construct. Theoretically, a sphere would be the best shape of a pressure vessel. Unhappily, a spherical shape is tough to manufacture, therefore more expensive, so most pressure vessels are cylindrical with 2:1 semielliptical heads or end caps on each end. Smaller pressure vessels are assembled from a pipe and two covers. A disadvantage of these vessels is that greater breadths are more expensive. Pressure vessels are used in a variety of applications in both industry and the private sector. They appear in these sectors as industrial compressed air receivers and domestic hot water storage tanks. Other examples of pressure vessels are diving cylinders, recompression chambers, distillation towers, autoclaves, and many other vessels in mining operations, oil refineries and petrochemical plants, nuclear reactor vessels, submarine and

Pipelines

516

7. Storage of petroleum fluids

space ship habitats, pneumatic reservoirs, hydraulic reservoirs under pressure, rail vehicle airbrake reservoirs, road vehicle airbrake reservoirs, and storage vessels for liquefied gases such as ammonia, chlorine, propane, butane, and LPG. 7.2.6.1 Spherical pressure vessel (sphere) This type of vessel is preferred for the storage of high-pressure fluids. A sphere is a very strong structure. The even distribution of stresses on the sphere’s surfaces, both internally and externally, generally means that there are no weak points. Spheres, however, are much more costly to manufacture than cylindrical vessels. Storage spheres need ancillary equipment similar to tank storage, for example, access manholes, pressure-vacuum vent that is set to prevent venting loss from boiling and breathing loss from daily temperature or barometric pressure changes, access ladders, earthing points (Fig. 7.14). An advantage of spherical storage vessels is that they have a smaller surface area per unit volume than any other shape of vessel. This means that the quantity of heat transferred from warmer surroundings to the liquid in the sphere will be less than that for cylindrical or rectangular storage vessels (Picture 7.4).

FIGURE 7.14 Schematic of spherical storage vessel.

Pipelines

7.2 Oil storage

PICTURE 7.4

517

Miro refinery Karlsruhe, Germany.

7.2.6.2 Cylindrical pressure vessel Cylinders are widely used for storage due to their being less expensive to produce than spheres. However, cylinders are not as strong as spheres due to the weak point at each end. This weakness is reduced by hemispherical or rounded ends being fitted. If the whole cylinder is manufactured from thicker material than a comparable spherical vessel of similar capacity, storage pressure can be similar to that of a sphere. 7.2.6.3 Lifting and handling of a pressure vessel

7.2.6.4 Pressure vessel heads Ellipsoidal head, hemispherical head, and torispherical head are three types of ASME pressure vessel dished heads. Ellipsoidal head is also called a 2:1 elliptical head. The shape of this head is more economical because the height of the head is just a quarter of the diameter. Its radius varies between the major and minor axis.

Pipelines

518

7. Storage of petroleum fluids

Do

SF

Do

Ellipsoidal

THi

DH

THi

KR CR

CR

DH

SF

KR

Torispherical

Thk.

ITH R

S.F.

I.D. Hemispherical

FIGURE 7.15

Schematic of hemispherical storage vessels.

Hemispherical head is a sphere and is the ideal shape for a head because the pressure in the vessel is divided equally across the surface of the head. The radius (R) of the head equals the radius of the cylindrical part of the vessel. Torispherical heads have a dish with a fixed radius (CR), the size of which depends on the type of torispherical head. The transition between the cylinder and the dish is called the knuckle. The knuckle has a toroidal shape (Fig. 7.15).

7.2.7 Variable vapor pace tank Variable vapor space tanks are equipped with expandable vapor reservoirs to accommodate vapor volume fluctuations attributable to temperature and barometric pressure changes. Although variable vapor space tanks are sometimes used independently, they are normally connected to the vapor spaces of one or more fixed roof tanks. The two most common types of variable vapor space tanks are lifter roof tanks and flexible diaphragm tanks. Lifter roof tanks have a telescoping roof that fits loosely around the outside of the main tank wall. The space between the roof and the wall is closed by either a wet seal, which is a trough filled with liquid, or a dry seal, which uses a flexible coated fabric. Flexible diaphragm tanks use flexible membranes to provide expandable volume. They may be either separate gasholder units or integral units mounted atop fixed roof tanks. Variable vapor space tank losses occur during tank filling when vapor is displaced by liquid. Loss of vapor occurs only when the tank’s vapor storage capacity is exceeded.

Pipelines

7.3 Tankers for oil storage

519

7.2.8 Liquefied natural gas storage tank A LNG storage tank or LNG storage tank is a specialized type of storage tank used for the storage of LNG. LNG storage tanks can be found in ground, above ground, or LNG carriers. The common characteristic of LNG storage tanks is the ability to store LNG at the very low temperature of 2162 C. LNG storage tanks have double containers, where the inner contains LNG and the outer container contains insulation materials. The most common tank type is the full containment tank. Tanks are roughly 55 m (180 ft) high and 75 m in diameter. In LNG storage tanks, if LNG vapors are not released, the pressure and temperature within the tank will continue to rise. LNG is a cryogen and is kept in its liquid state at very low temperatures. The temperature within the tank will remain constant if the pressure is kept constant by allowing the boil-off gas to escape from the tank. This is known as autorefrigeration. The world’s largest above-ground tank (Delivered in 2000) is the 180 million liters full containment type for Osaka Gas Co., Ltd. The world’s largest tank (delivered in 2001) is the 200 million liters membrane type for Toho Gas Co., Ltd.

7.2.9 Contamination Soil contamination with oil storage tanks includes the hazardous waste, oil spills, sludge from the treatment process, and coke dust. Soil contamination reduces the fertility of the soil and introduces foreign particles, which may affect the growth and quality of crops. One of the environmental impacts that may arise out of the implementation and operation of the storage tanking is oil spill and evaporation of products polluted the area each activity involves in the operation of tank farm has a potential spill risk and evaporation of different types of gases causing pollution. The major air pollutants are as follows: sludge, nitrogen oxides (NOx), carbon monoxide (CO), hydrogen sulfide (H2S), and sulfur dioxide (SO2). Refineries also release hydrocarbons such as natural gas (methane) and other light volatile fuels and oils. Unlike the pollutants from a refinery, these pollutants are not infested with synthetic chemicals and toxic catalysts. As will be discussed, these gases and liquid contaminants can be processed sustainably using natural materials (Caro and Ka¨rger, 2020).

7.3 Tankers for oil storage The storage capability of oil tankers became prominent during the oil price crash of 2020 (Reed, 2020). A typical tanker can be rented for as little as $25,000/day—a cost that went upto more than $200,000 a day during the negative oil price event in 2020. Whenever there is an oil glut, tankers can become a temporary home. As much as two million barrels per vessel can be stored until a buyer is found. In 2020, China took advantage of lowest ever oil price and stored through numerous such vessels. Since the late 19th century, oil tankers have been used to transport large amounts of oil across oceans and waterways. Today roughly 60% of all oil transported around the world travels by tanker. An oil tanker’s capacity is measured based on its size in deadweight

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520

7. Storage of petroleum fluids

tonnes (DWT), which is the total weight a ship can safely carry (including the cargo, fuel, crew, and provisions) not including the weight of the ship itself. Tanker capacities can range from a few thousand DWT to 550,000 DWT (Fig. 7.16). The old-style sail-driven tankers were replaced with modern-day oil tankers during 1877 through 1885—the same period petroleum fuels became the most useful (Vassiliou, 2009). In 1876, Ludvig and Robert Nobel, brothers of Alfred Nobel, founded Branobel (short for Brothers Nobel) in Baku, Azerbaijan. It was, during the late 19th century, one of the largest oil companies in the world. Where the size of tankers had been more or less the same for 25 years, after World War II they have grown in size significantly, initially slowly [38]. A typical T2 tanker of the World War II era was 532 feet (162 m) long and had a capacity of 16,500 DWT [39]. A modern ultra-large crude carrier (ULCC) can be 1300 feet (400 m) long and have a capacity of 500,000 DWT [39]. Several factors encouraged this growth. Hostilities in the Middle FIGURE 7.16 Tanker types and capacities (Website 4).

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521

7.3 Tankers for oil storage

East, which interrupted traffic through the Suez Canal, contributed, as did nationalization of Middle East oil refineries [38]. Intense competition among shipowners also played a part [38]. But apart from these considerations, there is a simple economic advantage: the larger an oil tanker is, the more cheaply it can move crude oil, and the better it can help meet growing demands for oil [38]. Oil tankers are loosely classified based on their carrying capacity in DWT, which is the total weight of the ship (including cargo, crew, and provisions) minus the weight of the ship if it was empty. Very large crude carriers (VLCCs), first developed in the 1960s, have a capacity of over 200,000 DWT and can carry two million barrels of oil. ULCC can carry in excess of 320,000 DWT, roughly three million barrels of oil. Other categories of tankers include medium range (MR), Panamax (the largest tankers that can fit through the Panama Canal), Aframax, and Suezmax (the largest tankers that can fit through the Suez Canal). Table 7.3 lists the capacity of the world tanker fleet by size of vessel. Aframax, Suezmax, and VLCCs are generally arranged for the shipping of crude oil only, whereas Panamax and smaller vessels can generally carry a variety of petroleum products. New orders for tankers began expanding in the late 1990s and then again in 2006. Over the last 5 years, the average age for tankers has declined from 15 to 8 years. Table 7.4 lists the breakdown of various classifications of oil tankers. Similar to other branches of technology, the shipping sector also boomed during World War I as well as World war II. The United States Shipping Board (USSB) was established as an emergency agency by the 1916 Shipping Act (39 Stat. 729), on September 7, 1916. It was tasked with increasing the number of US ships supporting the World War I efforts. USSB program ended on March 2, 1934. A similar surge occurred during WWII. A shipbuilding program began with the passage of the Merchant Marine Act of 1936. However, World War II provided the impetus to intensify those efforts eventually leading to a shipbuilding program that produced 5500 vessels. Among them were 2710 mass-produced ships known as Liberty ships. American shipyards mass-produced tankers as well as cargo ships. Some 533 oil tankers like this were built during the war. After the second world war, it was expected that a large number of tankers would be laid up, which indeed happened. The War Shipping Board was marred in a number of scandals and fraudulent activities. The Board and Corporation were subsequently abolished on October 26, 1936, and their functions were transferred to the United States. Maritime Commission by the Merchant Marine Act (49 Stat. 1985) of 29 June 1936. However, fraudulent activities remained. Aristotle Onassis and Stavros Niarchos used this to buy tankers cheaply. TABLE 7.3 Tanker fleet (Capacity and orderbook as of February 2012) RS Platou (RS Platou, 2012). Size DWT tonnes

Fleet capacity million DWT

Orderbook million DWT

Panamax and smaller

Less than 80,000

95.9

22%

13.3

Aframax

80,000
120,000

98.3

22%

8.9

Suezmax

120,000
200,000

67.8

15%

15.9

VLCC

200,000
320,000

177.9

40%

34.5

439.9

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72.6

522

7. Storage of petroleum fluids

TABLE 7.4 Breakdown of various classifications of oil tankers (website 3). Size / Deadweight classification tonnage (DWT)

Avg dimension (length | height | draft in feet)

Average DWT / vessela

Approx # of vesselsb

# of orders in 2006c

Medium range 25,000
50,000

675 | 100 | 55

41,000

1273

330

Panamax

50,000
75,000

65,000

B809

46

Aframax

75,000
120,000

810 | 110 | 60

106,000

B900

160

Suezmax

120,000
180,000

950 | 150 | 60

161,000

B600

83

VLCC

200,000
320,000

1240 | 200 | 100

306,000

474

102

ULCC

320,000 1

86,000

4056

720

a

McQuilling Services, LLC, Orderbook Details (Apr 2006). Online. Available: http://www.mcqservices.com/McServices_repo.asp. Accessed: December 4, 2007. b McQuilling Services, LLC, Orderbook Details (Apr 2006). Online. Available: http://www.mcqservices.com/McServices_repo.asp. Accessed: December 4, 2007. Fleet sizes for Panamax, Aframax, and Suezmaz were estimated based on trends in ship deliveries and orders over the past 10 years. c McQuilling Services, LLC, 2006—A Record Year for Newbuilding Orders. Online. Available: http://www.mcqservices.com/McServices_repo. asp. Accessed: December 4, 2007. Most of the crude oil carriers that currently travel through the Strait of Hormuz are VLCCs carrying oil to markets in East Asia. A few smaller oil tankers make “quick” runs to India and other closer destinations. But of course, tankers are flexible: pretty much any ocean-going tanker can transport crude oil from the Persian Gulf to any part of the world, depending on market conditions. This page was last modified in August 2008.

The expected economic decline did not come, due to reasons amongst others the Marshall plan, with the demand for oil increasing to the point in 1947 that there was a shortage of tankers. Freight tariffs tripled overnight, enabling some to recoup their investment in one voyage (Huber, 2001). Daniel Keith Ludwig (June 24, 1897
August 27, 1992) was an American shipping businessman, who was also involved in many other industries. He pioneered the construction of supertankers in Japan, founded Exportadora de Sal, SA in Mexico and developed it as the largest salt company in the world, built a model community in association with the Jari project, which he pioneered, on the Amazon River in Brazil to produce pulp paper, and had numerous hotels around the world. He had started Universe Tankships in 1947 and began building larger tankers in his Welding Shipyards. The Bulkpetrol of 30,000 long tons was the largest tanker of its time. Four of the five Bulk class tankers sank, likely because welding technology was not yet fully understood. As larger ships could not be constructed in the yard at Norfolk, Virginia, Ludwig went to Japan where he introduced the block construction method at the Kure Naval Yard. Here, in 1952, he built the Petrokure of 38,000 long tons. That same year, Onassis had a tanker of 45,000 long tons built and also Niarchos had supertankers built. Both Onassis and Niarchos claimed to be the largest independent tanker owner in the world (Time Magazine, 1957) The new leviathans will be 131 ft. shorter but a full 16 ft. wider than the Queen Elizabeth, world’s biggest passenger liner. Though none of the ships will be able to squeeze through the Suez or Panama Canals, they will cost far less to operate while hauling far more cargo than smaller ships, even though forced to take longer routes.

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7.4 Gas storage

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The Sinclair Petrolore that Ludwig had built in 1955, was at 56,000 long tons not only the largest freighter in the world, but also a self-unloading ore-oil carrier, the only one of that type ever built. It exploded on December 6, 1960 near Brazil—likely because of cargo leakage in the double bottom—resulting in the largest spill until then with 60,000 tons (Devanney, 2006) In 1956, the Universe Leader of 85,000 long tons was built just before the Suez Crisis started with the seizure of the Pannegia (Time, 1957). In 10 years time, tanker size had quadrupled. In 1958, Ludwig broke the barrier of 100,000 long tons of heavy displacement. His Universe Apollo displaced 104,500 long tons, a 23% increase from the Universe Leader. In 1962, Niarchos had the 106,000 long ton SS Manhattan built. This was the largest merchant vessel ever built in the United States. It was converted to have ice-breaking capacities in 1969 and was the first commercial ship to cross the Northwest Passage. Although the voyage was a success, a second attempt to cross the passage in winter proved impossible, and there were numerous environmental concerns with the project, so it was canceled and the Trans-Alaska Pipeline System built (Table 7.5).

7.4 Gas storage In the past, LDCs have generally used underground storage exclusively to serve customer needs directly. However, some LDCs have recognized and have been able to pursue the opportunities for additional revenues available with the deregulation of underground storage. These LDCs, which tend to be the ones with large distribution systems and a number of storage facilities, have been able to manage their facilities so they can lease a portion of their storage capacity to third parties (often marketers) while still fully meeting their obligations to serve core customers. The deregulation of underground storage combined with other factors such as the growth in the number of natural gas-fired electricity generating plants has placed a premium on high-deliverability storage facilities. Many salt formation and other high-deliverability sites, both existing and underdevelopment, have been initiated by independent storage service providers, often smaller, more focused companies started by entrepreneurs who recognized the potential profitability of these specialized facilities. These facilities are used almost exclusively to serve third-party customers who can most benefit from the characteristics of these facilities, such as marketers and electricity generators.

7.4.1 History of “open access” to storage capacity Prior to 1994, interstate pipeline companies, which are subject to the jurisdiction of FERC, owned all of the natural gas flowing through their systems, including gas held in storage, and these companies had exclusive control over the capacity and utilization of their storage facilities. With the implementation of FERC Order 636, interstate pipeline companies were required to operate their storage facilities on an open-access basis. That is, the major portion of working gas capacity (beyond what may be reserved by the

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TABLE 7.5 World tanker fleet 1957
80. Number of vessels in each tonnage classa At year end

25
99 dwt

100
149 dwt

150
199 dwt

200 1 dwt

1957

427

0

0

0

1958

568

1959

715

1960

826

1961

892

2

1962

989

4

1963

1092

1964

1226

6

1965

1303

15

1966

1395

34

1967

1446

59

5

2

1968

1488

82

17

17

1969

1535

96

30

61

1970

1572

110

34

131

1971

1600

125

37

200

1972

1609

136

38

270

1973

1656

152

41

357

1974

1718

193

42

479

1975

1714

241

47

588

1976

1753

265

64

676

1977

1580

279

76

712

1978

1453

269

83

700

1979

1435

304

1980

1482

300

b

b

45

699

41

658

a

Tonnage Classes are in thousands of long tons, dwt. Size categories for these years are 100,000
159,999 dwt and 160,000
199,999 dwt. From Huber, M., 2001, Tanker Operations: A Handbook for the Person-In-Charge (PIC). Cambridge, MD, Cornell Maritime Press. ISBN 0
87033
528-6.

b

pipeline/operator to maintain system integrity and for load balancing) at each site must be made available for lease to third parties on a nondiscriminatory basis. Today, in addition to the interstate storage sites, many storage facilities owned/operated by large LDCs, intrastate pipelines, and independent operators also operate on an

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open-access basis, especially those sites affiliated with natural gas market centers. Open access has allowed storage to be used other than simply as backup inventory or as a supplemental seasonal supply source. For example, marketers and other third parties may move natural gas into and out of storage (subject to the operational capabilities of the site or the tariff limitations) as changes in price levels present opportunities to buy and store natural gas when demand is relatively low, and sell during periods of peak demand when the price is elevated. Further, storage is used in conjunction with various financial instruments (e.g., futures and options contracts, and swaps) in creative and complex ways in an attempt to profit from market conditions. Reflecting this change in focus within the natural gas storage industry during recent years, the largest growth in daily withdrawal capability has been from high-deliverability storage sites, which include salt cavern storage reservoirs as well as some depleted oil or natural gas reservoirs. These facilities can cycle their inventories—that is, completely withdraw and refill working gas (or vice versa)—more rapidly than can other types of storage, a feature more suitable to the flexible operational needs of today’s storage users. Since 1993, daily withdrawal capability from high-deliverability salt cavern storage facilities has grown significantly. Nevertheless, conventional storage facilities continue to be very important to the industry.

7.4.2 Underground natural gas storage data The US Energy Information Administration (EIA) collects a variety of data on the storage measures discussed above, and EIA publishes selected data on a weekly, monthly, and annual basis. EIA uses Form 9121, Weekly Natural Gas Storage Report, to collect data on end-of-week working gas in storage at the company and regional level from a sample of all underground natural gas storage operators. The regions used for weekly reporting were formally the East, West, and Producing regions. In October 2015, EIA increased the number of regions and changed their names to better align the storage locations with the markets they serve and to provide more information to market observers and participants. Data from the EIA-912 survey are tabulated and published weekly at regional and national levels. The EIA-191 (Monthly Underground Natural Gas Storage Report) working and base gas in reservoirs, injections, withdrawals, and location of reservoirs are reported by operators of all underground natural gas storage fields on a monthly basis. This form collects data on total capacity, base gas, working gas, injections, and withdrawals, by reservoir and by storage facility, from all underground natural gas storage operators. Data derived from the EIA-191 survey are published at a state level on a monthly basis in the Natural Gas Monthly, with select data available at the field level in the Natural Gas Respondent Query System. The data shown in the Natural Gas Monthly include tabulations of base gas, total inventories, total storage capacity, injections, and withdrawals at state and regional levels.

1

Weekly Natural Gas Storage Report. Collects information on natural gas inventories held in U.S. underground storage facilities. Storage estimates will be collected for five multistate regions comprising the lower 48 States.

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7.4.3 Storage measures Several volumetric measures are used to quantify the fundamental characteristics of an underground storage facility and the gas contained within it. For some of these measures, it is important to distinguish between the characteristic of a facility, such as its capacity, and the characteristic of the natural gas within the facility such as the actual inventory level. These measures are as follows: Total natural gas storage capacity is the maximum volume of natural gas that can be stored in an underground storage facility in accordance with its design, which comprises the physical characteristics of the reservoir, installed equipment, and operating procedures particular to the site. Total gas in storage is the volume of natural gas in the underground facility at a particular time. Base gas (or cushion gas) is the volume of natural gas intended as permanent inventory in a storage reservoir to maintain adequate pressure and deliverability rates throughout the withdrawal season. Working gas capacity refers to total gas storage capacity minus base gas. Working gas is the volume of gas in the reservoir above the level of base gas. Working gas is available in the marketplace. Deliverability is most often expressed as a measure of the amount of gas that can be delivered (withdrawn) from a storage facility on a daily basis. Also referred to as the deliverability rate, withdrawal rate, or withdrawal capacity, deliverability is usually expressed in terms of million cubic feet per day (MMcf/d). Occasionally, deliverability is expressed in terms of equivalent heat content of the gas withdrawn from the facility, most often in dekatherms per day (a therm is 100,000 Btu, which is roughly equivalent to 100 cubic feet of natural gas; a dekatherm is the equivalent of about 1000 cubic feet (Mcf)). The deliverability of a given storage facility is variable, and it depends on factors such as the amount of natural gas in the reservoir at any particular time, the pressure within the reservoir, the compression capability available to the reservoir, the configuration and capabilities of surface facilities associated with the reservoir, and other factors. In general, a facility’s deliverability rate varies directly with the total amount of natural gas in the reservoir; it is at its highest when the reservoir is most full and declines as working gas is withdrawn. Injection capacity (or rate) is the complement of the deliverability or withdrawal rate—it is the amount of natural gas that can be injected into a storage facility on a daily basis. As with deliverability, injection capacity is usually expressed in MMcf/d, although dekatherms/day is also used. The injection capacity of a storage facility is also variable, and it is dependent on factors comparable to those that determine deliverability. By contrast, the injection rate varies inversely with the total amount of gas in storage; it is at its lowest when the reservoir is most full and increases as working gas is withdrawn. None of these measures for any given storage facility are fixed or absolute. The rates of injection and withdrawal change as the level of natural gas varies within the facility. In practice, a storage facility may be able to exceed certificated total capacity in some circumstances by exceeding certain operational parameters. The facility’s total capacity can also vary, temporarily or permanently, as its defining parameters vary. Measures of base gas, working gas, and working gas capacity also can also change from time to time. These changes occur,

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for example, when a storage operator reclassifies one category of natural gas to the other, often as a result of new wells, equipment, or operating practices (such a change generally requires approval by the appropriate regulatory authority). Finally, storage facilities can withdraw base gas for supply to market during times of particularly heavy demand, although by definition, this gas is not intended for that use. Mass and energy balance equations form the core of every type of fluid movement in petroleum reservoirs. The fundamental principle is material balance, in which mass in 5 mass out 1 mass left within a confined domain. All mathematical models are based on this material balance principle, as shown in the following basic material balance equation:  

1 Wp Bw 2 Winj Bwinj 2 Ginj Bginj Np B8 o 1 Bg Rp 2 Rs 0 19 = <

Boi   cf 1 cw Sw 5 N Bo 2 Boi 1 Bg ðRsi 2 Rs Þ 1 m Bg 2 Bgi 1 Boi ð1 1 mÞ@ ΔpA 1 We Bw ; : Bgi 1 2 Sw (7.1) where various terms hold the following meanings (Table 7.6). Gas material balance is a simplified version of the general material balance equation. When the general equation is reduced to its simplest form containing only gas terms, it appears as shown in the following equation: G5 

Gp Bg  Bg 2 Bgi

(7.2)

In this equation, it is assumed that gas expansion is the only driving force causing production. This form is commonly used because the expansion of gas often dominates over the expansion of oil, water, and rock. Bg is the ratio of gas volume at reservoir conditions to gas volume at standard conditions. This is expanded using the real gas law: Bg 5

Vres Zres nRTres pstd 5 Vstd Zstd nRTstd pres

(7.3)

The reservoir temperature is considered to remain constant. The compressibility factor (Z) for standard conditions is assumed to be 1. The number of moles of gas do not change from reservoir to surface. Standard temperature and pressure are known constants. When Bg is replaced and the constants are canceled out, the gas material balance equation then simplifies as follows:  p pi 1 pi 52 Gp 1 (7.4) Z Zi G Zi When plotted on a graph of p/Z versus cumulative production, the equation can be analyzed as a linear relationship. Several measurements of static pressure and the corresponding cumulative productions can be used to determine the x-intercept of the plot— the original gas-in-place, shown as G in the equation. For a volumetric gas reservoir, gas expansion (the most significant source of energy) dominates depletion behavior; the general gas material balance equation is a very simple

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TABLE 7.6 Various terms of the general material balance equation. Terms

Meaning  

F 5 Np Bo 1 Bg Rp 2 Rs 1 Wp Bw 2 Winj Bwinj 2 Ginj Bginj Volume of withdrawal (production and injection) at reservoir conditions is determined by the oil, water, and gas produced at the surface. Et 5 Eo 1

Boi Bgi

mEg 1 Boi ð1 1 mÞEfw

Total expansion.

Eo 5 Bo 2 Boi 1 Bg ðRsi 2 Rs Þ

If the oil column is initially at the bubble point, reducing the pressure will result in the release of gas and the shrinkage of oil. The remaining oil will consist of oil and the remaining gas still dissolved at the reduced pressure.

Eg 5 Bg 2 Bgi

Gas expansion factor. For example, as the reservoir depletes, the gas cap expands into reservoir volume previously occupied by oil.

Efw 5

m5

cf 1 cw Sw 1 1 Sw

GBgi NBoi

We Bw

Δp

Even though water has low compressibility, the volume of connate water in the system is usually large enough to be significant. The water will expand to fill the emptying pore spaces as the reservoir depletes. As the reservoir is produced, the pressure declines and the entire reservoir pore volume is reduced due to compaction. The change in volume expels an equal volume of fluid as production and is therefore additive in the expansion terms. Ratio of gas cap to original oil in place. A gas cap also implies that the initial pressure in the oil column must be equal to the bubble point pressure. If the reservoir is connected to an active aquifer, then once the pressure drop is communicated throughout the reservoir, the water will encroach into the reservoir resulting in a net water influx. To calculate the amount of water influx, either the

From Fekete, 2021, http://www.fekete.com/, accessed February 23, 2021.

yet powerful tool for interpretation. However, in cases where other sources of energy are significant enough to cause deviation from the linear behavior of a p/Z plot, a more sophisticated tool is required. For this, a more advanced form of the material balance equation has been developed, and the standard p/Z plot is modified to maintain a linear trend with the simplicity of interpretation. The success and usefulness of the p/Z plot in conventional reservoir led to its application in unconventional reservoirs such as coal bed methane (CBM) and shale/tight gas reservoirs. In his work on CBM, King (1993) introduced p/Z* to replace p/Z. By modifying Z, parameters to incorporate the effects of adsorbed gas were incorporated so the total gas-in-place is interpreted rather than just the free gas-in-place; a straight-line analysis technique is still used. This concept has been extended to additional reservoir types with Fekete’s p/Z** method (Moghadam et al., 2011).

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The reservoir types considered in the advanced material balance equation are as follows: overpressured reservoirs, water-drive reservoirs, and connected reservoirs. The total Z** equation is shown below with the modified material balance equation:  Gp p pi (7.5) 5  1 2 G ZTT Zi ZTT 5 h

 1 p Sgi Z Sgi

p

 2 cwip 2 cep 2 cd 1

pi Zi



G Gf

21

i

Gf G

(7.6)

Despite its usefulness, the p/Z plot may give inaccurate results when applied directly to unconventional reservoirs such as coal/shale. This is because in its conventional form, it did not include other sources of gas storage such as connected reservoirs or adsorption, which is present in coal/shale reservoirs (Moghadam et al., 2011). This led to the modification of P/Z plot in order for it to be suitably applied to unconventional reservoirs especially for coal/shale gas reservoirs. Unconventional reservoirs such as coal/shale are characterized by gas adsorption, hence incorporating adsorption into the derivation of the P/Z method is necessary for accurate prediction of hydrocarbons in place for such reservoirs. This requires an adsorption model that can correctly represent the adsorption phenomenon within these reservoirs. The injected gas volume in a depleted gas reservoir can be calculated by using a similar approach as discussed in the above section. Assuming the reservoir pore volume is constant, the initial gas-in-place in the depleted gas reservoir in standard conditions is Gi, and the total gas volume in storage facility is G, then the cumulative injected gas volume, Gs is as follows: Gs 5 G2Gi or, by employing the formation volume factors at initial and final conditions  Bgi Bgi 2 Gi 5 Gi 21 G 5 Gi Bg Bg

(7.7)

(7.8)

Note: the Gi is the residual gas in a depleted gas reservoir that will be used for storage, or the initial gas in a storage field after the seasonal withdrawal and at the beginning of the resumption of injection. It can be calculated by substituting Eqs. (7.6) and (7.7) into Eq. (7.8) and assuming the temperature is constant:   3 res ft =scf : Bg 5 0:0283 ZT p Gi 5 43; 560 Eq. (7.8) becomes

 Gs 5 Gi

AhϕSg ðscfÞ; Bgi

 p=Z Gi p pi : 2 21 5 pi =Zi Z Zi pi =Zi

(7.9)

(7.10)

In these equations, the subscript i stands for the initial conditions of the gas storage. The pressures are measured when the storage is at its maximum and minimum capacities. The pressures measured are then near the maximum and minimum pressures.

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FIGURE 7.17

p/Z curve vs cumulative gas storage.

p/ Ɀ, psi

Slope=(pi /Ɀ i )/Gi

pi/Ɀ i Gs, Bcf

A typical p/Z versus Gs can be plotted as shown in Fig. 7.17. A plot of p/Z versus Gs should yield a straight line and the slope should be (pi/Zi)/Gi. Therefore, the initial gas-in-place can be obtained by the following equation:   (7.11) Gi 5 pi =Zi =slope: pi/Zi can be determined by measuring the pressure at initial conditions through a pressure buildup test. Assuming that Ginj volumes of gas and Winj volumes of water have been injected for pressure maintenance, the total pore volume occupied by the two injected fluids is given by the following equation: Total volume 5 GinjBginj 1 WinjBw where Ginj 5 cumulative gas injected, scf, Bginj 5 injected gas formation volume factor, bbl/scf, Winj 5 cumulative water injected, STB, and Bw 5 water formation volume factor, bbl/STB. Combining Equations 11
3 through 11
12 with Equation 11
2 and rearranging gives the following equation:     Np Bo 1 Gp 2 Np Rs Bg 2 We 2 Wp Bw 2 Ginj Bginj 2 Winj Bw h i h i (7.12) N5 S c w 1 cf B ðBo 2 Boi Þ 1 ðRsi 2 Rs ÞBg 1 mBoi Bgig 2 1 1 Boi ð1 1 mÞ wi 1 2 Swi Δp where N 5 initial oil in place, STB, Gp 5 cumulative gas produced, scf, Np 5 cumulative oil produced, STB, Rsi 5 gas solubility at initial pressure, scf/STB, m 5 ratio of gas-cap gas volume to oil volume, bbl/bbl, Bgi 5 gas formation volume factor at pi, bbl/scf, and Bginj 5 gas formation volume factor of the injected gas, bbl/scf. The cumulative gas produced Gp can be expressed in terms of the cumulative gas
oil ratio Rp and cumulative oil produced Np as follows:

Finally,

Gp 5 Rp Np

(7.13)

    Np Bo 1 Rp 2 Rs Bg 2 We 2 Wp Bw 2 Ginj Bginj 2 Winj Bwi h i h i N5 S c w 1 cf B ðBo 2 Boi Þ 1 ðRsi 2 Rs ÞBg 1 m Boi Bgig 2 1 1 Boi ð1 1 mÞ wi 1 2 Swi Δp

(7.14)

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The above relationship is referred to as the material balance equation (MBE). A more convenient form of the MBE can be determined by introducing the concept of the total (two-phase) formation volume factor Bt into the equation. This oil Pressure-VolumeTemperature (PVT) property is defined as follows: Bt 5 Bo 1 Rsi 2 Rs Bg

(7.15)

Introducing Bt into Eq. (7.14) and assuming, for sake of simplicity, no water or gas injection, the following equation can be obtained:     Np Bt 1 Rp 2 Rsi Bg 2 We 2 Wp Bw h i h i N5 (7.16) S c w 1 cf B ðBt 2 Bti Þ 1 mBti Bgig 2 1 1 Bti ð1 1 mÞ wi 1 2 Swi Δp where Swi 5 initial water saturation, 5 cumulative produced gas
oil ratio, scf/STB, and Δp 5 change in the volumetric average reservoir pressure, psi. In a combination drive reservoir where all the driving mechanisms are simultaneously present, it is of practical interest to determine the relative magnitude of each of the driving mechanisms and its contribution to the production. Rearranging Eqs. (7.11)
(7.17) gives the following equation:   W e 2 W p Bw N ðBt 2 Bti Þ NmBti Bg 2 Bgi =Bgi 1 1 A A A 2 3  cw Swi 1 cf  (7.17) 5 pi 2 p NBoi ð1 1 mÞ4 1 2 Swi 51 1 A with the parameter A as defined by the following equation: A 5 NpBt 1 Rp 2 RsiBg

(7.18)

Eq. (7.17) can be abbreviated and expressed as follows: DDI 1 SDI 1 WDI 1 EDI 5 1:0

(7.19)

where DDI 5 depletion-drive index, SDI 5 segregation (gas-cap)-drive index, WDI 5 waterdrive index, and EDI 5 expansion (rock and liquid)-drive index. Gas storage is principally used to meet load variations. Gas is injected into storage during periods of low demand and withdrawn from storage during periods of peak demand. It is also used for a variety of secondary purposes as follows: 1. Balancing the flow in pipeline systems. This is performed by mainline transmission pipeline companies to maintain operational integrity of the pipelines, by ensuring that the pipeline pressures are kept within design parameters. 2. Maintaining contractual balance. Shippers use stored gas to maintain the volume they deliver to the pipeline system and the volume they withdraw. Without access to such storage facilities, any imbalance situation would result in a hefty penalty.

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7. Storage of petroleum fluids

3. Leveling production over periods of fluctuating demand. Producers use storage to store any gas that is not immediately marketable, typically over the summer when demand is low and deliver it in the winter months when the demand is high. 4. Market speculation. Producers and marketers use gas storage as a speculative tool, storing gas when they believe that prices will increase in the future and then selling it when it does reach those levels. 5. Insuring against any unforeseen accidents. Gas storage can be used as an insurance that may affect either production or delivery of natural gas. These may include natural factors such as hurricanes, or malfunction of production or distribution systems. 6. Meeting regulatory obligations. Gas storage ensures to some extent the reliability of gas supply to the consumer at the lowest cost, as required by the regulatory body. This is why the regulatory body monitors storage inventory levels. 7. Reducing price volatility. Gas storage ensures commodity liquidity at the market centers. This helps contain natural gas price volatility and uncertainty. 8. Offsetting changes in natural gas demands. Gas storage facilities are gaining more importance due to changes in natural gas demands. First, traditional supplies that once met the winter peak demand are now unable to keep pace. Second, there is a growing summer peak demand on natural gas, due to electric generation via gas-fired power plants. Most existing natural gas storage in the United States is in depleted natural gas or oil fields that are close to consumption centers. Conversion of a field from production to storage duty takes advantage of existing wells, gathering systems, and pipeline connections. Depleted oil and natural gas reservoirs are the most commonly used underground storage sites because of their wide availability. In some areas, most notably the midwestern United States, natural aquifers have been converted to natural gas storage reservoirs. An aquifer is suitable for gas storage if the waterbearing sedimentary rock formation is overlaid with an impermeable cap rock. Although the geology of aquifers is similar to depleted production fields, their use for natural gas storage usually requires more base (cushion) gas and allows less flexibility in injecting and withdrawing. Deliverability rates may be enhanced by the presence of an active water drive, which supports the reservoir pressure through the injection and production cycles. Salt caverns provide very high withdrawal and injection rates relative to their working gas capacity. Base gas requirements are relatively low. Most salt cavern storage facilities have been developed in salt dome formations located in the Gulf Coast states. Salt caverns have also been made (by a process called leaching) in bedded salt formations in Northeastern, Midwestern, and Southwestern states. Cavern construction is more costly than depleted field conversions when measured on the basis of dollars per thousand cubic feet of working gas capacity, but the ability to perform several withdrawal and injection cycles each year reduces the per-unit cost of each thousand cubic feet of gas injected and withdrawn. Fig. 7.18 shows a stylized representation of the various types of underground storage facilities.

7.4.4 Owners and operators of storage facilities The principal owners/operators of underground storage facilities are interstate pipeline companies, intrastate pipeline companies, LDCs, and independent storage service providers.

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FIGURE 7.18 Types of underground natural gas storage facilities.

About 120 entities currently operate the nearly 400 active underground storage facilities in the lower 48 states. If a storage facility serves interstate commerce, it is subject to the jurisdiction of the FERC; otherwise, it is state regulated. Owners/operators of storage facilities are not necessarily the owners of the natural gas held in storage. In fact, most working gas held in storage facilities is held under lease with shippers, LDCs, or end users who own the gas. The type of entity that owns/operates the facility will determine to some extent how that facility’s storage capacity is utilized. For example, interstate pipeline companies rely heavily on underground storage to facilitate load balancing and system supply management on their long-haul transmission lines. FERC regulations allow interstate pipeline companies to reserve some portion of their storage capacity for this purpose. Nonetheless, the bulk of their storage capacity is leased to other industry participants. Intrastate pipeline companies also use storage capacity and inventories for similar purposes, in addition to serving customers.

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7. Storage of petroleum fluids

In the past, LDCs have generally used underground storage exclusively to serve customer needs directly. However, some LDCs have recognized and have been able to pursue the opportunities for additional revenues available with the deregulation of underground storage (see “Open Access” to Storage Capacity, below). These LDCs, which tend to be the ones with large distribution systems and a number of storage facilities, have been able to manage their facilities so they can lease a portion of their storage capacity to third parties (often marketers) while still fully meeting their obligations to serve core customers (of course, these arrangements are subject to approval by the respective state-level regulators). The deregulation of underground storage combined with other factors such as the growth in the number of natural gas-fired electricity generating plants has placed a premium on high-deliverability storage facilities. Many salt formation and other high-deliverability sites, both existing and underdevelopment, have been initiated by independent storage service providers, often smaller, more focused companies started by entrepreneurs who recognized the potential profitability of these specialized facilities. These facilities are used almost exclusively to serve third-party customers who can most benefit from the characteristics of these facilities, such as marketers and electricity generators.

7.4.5 History of “open access” to storage capacity Prior to 1994, interstate pipeline companies, which are subject to the jurisdiction of FERC, owned all of the natural gas flowing through their systems, including gas held in storage, and these companies had exclusive control over the capacity and utilization of their storage facilities. With the implementation of FERC Order 636, interstate pipeline companies were required to operate their storage facilities on an open-access basis. That is, the major portion of working gas capacity (beyond what may be reserved by the pipeline/operator to maintain system integrity and for load balancing) at each site must be made available for lease to third parties on a nondiscriminatory basis. Today, in addition to the interstate storage sites, many storage facilities owned/operated by large LDCs, intrastate pipelines, and independent operators also operate on an open-access basis, especially those sites affiliated with natural gas market centers. Open access has allowed storage to be used other than simply as backup inventory or as a supplemental seasonal supply source. For example, marketers and other third parties may move natural gas into and out of storage (subject to the operational capabilities of the site or the tariff limitations) as changes in price levels present opportunities to buy and store natural gas when demand is relatively low, and sell during periods of peak-demand when the price is elevated. Further, storage is used in conjunction with various financial instruments (e.g., futures and options contracts, and swaps) in creative and complex ways in an attempt to profit from market conditions. Reflecting this change in focus within the natural gas storage industry during recent years, the largest growth in daily withdrawal capability has been from high-deliverability storage sites, which include salt cavern storage reservoirs as well as some depleted oil or natural gas reservoirs. These facilities can cycle their inventories—that is, completely withdraw and refill working gas (or vice versa)—more rapidly than can other types of storage, a feature more suitable to the flexible operational needs of today’s storage users.

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Since 1993, daily withdrawal capability from high-deliverability salt cavern storage facilities has grown significantly. Nevertheless, conventional storage facilities continue to be very important to the industry.

7.4.6 Underground natural gas storage data The US EIA collects a variety of data on the storage measures discussed above, and EIA publishes selected data on a weekly, monthly, and annual basis. EIA uses Form EIA-912, Weekly Natural Gas Storage Report, to collect data on end-of-week working gas in storage at the company and regional level from a sample of all underground natural gas storage operators. The regions used for weekly reporting were formally the East, West and Producing regions. In October 2015, EIA increased the number of regions and changed their names to better align the storage locations with the markets they serve and to provide more information to market observers and participants. Data from the EIA-912 survey are tabulated and published weekly at regional and national levels. The EIA-191, Monthly Underground Gas Storage Report, collects data on total capacity, base gas, working gas, injections, and withdrawals, by reservoir and by storage facility, from all underground natural gas storage operators. Data derived from the EIA-191 survey are published at a state level on a monthly basis in the Natural Gas Monthly, with select data available at the field level in the Natural Gas Respondent Query System. The data shown in the Natural Gas Monthly include tabulations of base gas, total inventories, total storage capacity, injections, and withdrawals at state and regional levels. 7.4.6.1 Storage measures Several volumetric measures are used to quantify the fundamental characteristics of an underground storage facility and the gas contained within it. For some of these measures, it is important to distinguish between the characteristic of a facility, such as its capacity, and the characteristic of the natural gas within the facility such as the actual inventory level. These measures are as follows: 7.4.6.2 Total natural gas storage capacity Total natural gas storage capacity is the maximum volume of natural gas that can be stored in an underground storage facility in accordance with its design, which comprises the physical characteristics of the reservoir, installed equipment, and operating procedures particular to the site. Total gas in storage is the volume of natural gas in the underground facility at a particular time. Base gas (or cushion gas) is the volume of natural gas intended as permanent inventory in a storage reservoir to maintain adequate pressure and deliverability rates throughout the withdrawal season. Working gas capacity refers to total gas storage capacity minus base gas. Working gas is the volume of gas in the reservoir above the level of base gas. Working gas is available to the marketplace.

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7. Storage of petroleum fluids

Deliverability is most often expressed as a measure of the amount of gas that can be delivered (withdrawn) from a storage facility on a daily basis. Also referred to as the deliverability rate, withdrawal rate, or withdrawal capacity, deliverability is usually expressed in terms of million cubic feet per day (MMcf/d). Occasionally, deliverability is expressed in terms of equivalent heat content of the gas withdrawn from the facility, most often in dekatherms per day [a therm is 100,000 Btu, which is roughly equivalent to 100 cubic feet of natural gas; a dekatherm is the equivalent of about one thousand cubic feet (Mcf)]. The deliverability of a given storage facility is variable, and it depends on factors such as the amount of natural gas in the reservoir at any particular time, the pressure within the reservoir, the compression capability available to the reservoir, the configuration and capabilities of surface facilities associated with the reservoir, and other factors. In general, a facility’s deliverability rate varies directly with the total amount of natural gas in the reservoir; it is at its highest when the reservoir is most full and declines as working gas is withdrawn. Injection capacity (or rate) is the complement of the deliverability or withdrawal rate
it is the amount of natural gas that can be injected into a storage facility on a daily basis. As with deliverability, injection capacity is usually expressed in MMcf/d, although dekatherms/day is also used. The injection capacity of a storage facility is also variable, and it is dependent on factors comparable to those that determine deliverability. By contrast, the injection rate varies inversely with the total amount of gas in storage; it is at its lowest when the reservoir is most full and increases as working gas is withdrawn. None of these measures for any given storage facility are fixed or absolute. The rates of injection and withdrawal change as the level of natural gas varies within the facility. In practice, a storage facility may be able to exceed certificated total capacity in some circumstances by exceeding certain operational parameters. The facility’s total capacity can also vary, temporarily or permanently, as its defining parameters vary. Measures of base gas, working gas, and working gas capacity also can also change from time to time. These changes occur, for example, when a storage operator reclassifies one category of natural gas to the other, often as a result of new wells, equipment, or operating practices (such a change generally requires approval by the appropriate regulatory authority). Finally, storage facilities can withdraw base gas for supply to market during times of particularly heavy demand, although by definition, this gas is not intended for that use (Fig. 7.19). The United States has approximately 5 Tcf of natural gas storage capacity that is capable of delivering upto 1182 Bcf/d of natural gas supplies (Fang et al., 2016). This maximum deliverability exceeds the highest historical average end-use natural gas consumption observed in the United States, in January 2014. Approximately 55% of working gas capacity is owned and operated by pipeline companies, 26% by LDCs, investor-owned utilities, or municipalities (collectively “LDCs”), and the remaining capacity (18%) is owned by independent storage operators. Correspondingly, 54% of storage deliverability are owned by pipelines, 27% by LDCs, and 27% by independent storage service providers. Pipeline or LDC-owned storage facilities are primarily low-deliverability fields while the high deliverability salt domes are primarily owned by independent operators. 2

Volatility reflects how much prices can move overa certain period of time in percentage terms. For example, 100% annualized volatility indicates that the prices could likely move up or downby 100% in a year. The higher the volatility, the more dramatic price path can be.

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FIGURE 7.19 Working gas capacity over the years. Investing.com, 2022, https://www.investing.com/economiccalendar/natural-gas-storage-386. TABLE 7.7 US lower 48 storage characteristics. Number of Working % of Total fields by gas capacity working gas type (Bcf) capacity

Total field capacity (Bcf)

% of Total field capacity

Maximum daily deliverability (Bcf/d)

% of Total maximum daily deliverability5

Aquifer

46

9%

1445

16%

9.7

8%

Depleted field

333

3845

80%

7086

77%

75.5

64%

Salt dome

39

489

10%

703

8%

33.1

28%

Total

418

4786

100%

9233

100%

118.3

100%

452

All storage fields in the US report their total working gas capacity, total field capacity, and maximum daily deliverability. Working gas capacity refers to the amount of gas available for injections and withdrawals. Total field capacity refers to working gas capacity plus base gas which is gas that is necessary to have in storage at all times in order to maintain operational standards. Daily deliverability is the maximum amount of gas that any given storage facility can dispatch in a single day. As of the end of 2014, there were more than over 400 storage facilities in the United States with nearly 4.8 Tcf of working gas capacity and capable of delivering more than 118 Bcf/d of supplies. They consist of 333 depleted fields, 46 aquifers, and 39 salt dome facilities, as listed in Table 7.7. As shown in Fig. 7.20, depleted fields are depleted natural gas or oil reservoirs, scattered throughout most US regions with storage facilities. They typically require a long injection season with moderate withdrawals during winter months. Even though depleted fields represent 80% of total working gas capacity, they only account for 64% of total maximum daily deliverability capabilities.

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FIGURE 7.20

7. Storage of petroleum fluids

US Underground natural gas storage facilities by type (July 2015).

Aquifer storage facilities are converted natural aquifers with water-bearing sedimentary rock formation overlaid with an impermeable cap rock. Aquifer storage typically requires larger base gas reserves and allows for less flexibility in injecting and withdrawing. Aquifers make up 9% of working gas capacity and 8% of maximum daily deliverability in the United States. The midwest has the most aquifer storage. Salt dome storage facilities are naturally formed salt caverns shaped into a dome structure through leaching and dissolving the salt. Most salt dome storage facilities are located in the Gulf Coast states (South Central storage region) while a few exist in the Midwest and East regions. Salt dome storage requires very little base gas and provides high deliverability rates relative to working gas capacity. In the United States., salt dome facilities account for 10% of working gas capacity and 28% of maximum daily deliverability. The storage facilities owned by utilities are used by themselves to meet their customers’ needs. On the other hand, the majority of storage facilities owned and operated by pipeline and independent service providers are contracted by third-party shippers. ICF International identified the composition of these third-party shippers using the Index of Customers data released by all interstate pipelines and certain independent storage operators every quarter. The Index of Customers data covers nearly 80% of total US storage capacity owned and operated by pipelines and independent storage operators. According to the most recent index of customers data from the fourth-quarter of 2015, among the 2270 Bcf of storage capacity, 38% of the capacity are contracted by natural Gas LDCs, 18% by power and gas utilities, and 26% by marketers and traders. A large amount of storage capacity is either owned or firmly contracted by natural gas and electric utilities to offset the naturally occurring seasonal pattern of US natural gas

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FIGURE 7.21 Monthly US demand.

demand. As shown in Fig. 7.21, the peak monthly average demand in the United States exceeds 100 Bcf/d while the lowest months are less than 60 Bcf/d. The seasonal demand difference requires natural gas storage as a key supply source in wintertime since natural gas production is steady on a monthly basis. The seasonality of natural gas demand depends on weather, when winter is cold, the seasonal demand pattern is peakier when more gas is needed during the winter months, which were the cases for the winters of 2013
14 and 2014
15. The weather normalized natural gas demand seasonality remains relatively stable over time. Demand for natural gas from the power sector varies widely between the two cases, as renewable penetration is the driving difference between the LOGR case and the Base case. The EPSA LOGR case forecasts a decline in consumption from the power sector in all regions except the Midwest (East & North Central). The EPSA Base case also forecasts very moderate to flat demand in the Pacific, Mountain, South Central, and Northeastern (New England & Mid-Atlantic) markets. The South Atlantic and Midwest markets are forecast to grow between 3% and 6% per year throughout the projection. Natural gas is injected into storage facilities in the summer time when seasonal demand is relatively low and withdrawn in wintertime as an incremental supply source. Therefore, the utilization of storage capacity follows a distinct seasonal pattern, with gas inventory in the storage built up from April through October, and withdrawn down to the lowest level in March. Fig. 7.22 shows that for the past 5 years, storage inventory level range was fairly narrow from September to November, while much wider in other months depending on market and weather conditions. This shows that the United States has enough flexibility in storage operation to achieve an appropriate storage inventory ready for the upcoming winter. For example, persistent colder than normal weather starting in November, during the 2013
14 winter, drained storage inventory to unprecedented levels in December. The shortage of gas supplies during cold snaps in January through March caused dramatic price spikes in many parts of the country. Despite the historic depletion, storage inventory was built back to the normal range for the 2014
15 winter.

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FIGURE 7.22

US storage inventory.

FIGURE 7.23

Historical monthly US demand and supply balance.

7.4.7 US demand and supply balance From a total supply and demand balance perspective, the role of storage in meeting US natural gas demand has not changed very significantly despite a major production uptick over the past 5 years. The usage pattern reflects the fact that most storage capacity is contracted for long-term capacity and owned by LDCs, whose usage for the facility depends upon their seasonal needs for natural gas. The percentage of winter demand met by storage supplies ranges between 20% and 26%, fluctuating with winter weather conditions as seen in Fig. 7.23 As will be discussed later, higher production dampens the value and utilization of high-deliverability salt dome facilities. The EIA reports natural gas storage data for five regions in the United States: the East, Midwest, Mountain, South Central, and Pacific.

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Storage inventory by region for the last 5 years on record is depicted in Fig. 7.24 and summarized in Table 7.8. The East and Midwest regions’ storage inventory levels are fairly consistent with maximum inventory utilization nearing 90%. The approximate peak storage deliverability utilization is estimated at 46% and 68% for the East and Midwest regions respectively during the 2013
14 winter. Historically, the Mountain region has the least utilized storage inventory with a max inventory utilization of 52%; however, the Mountain region’s approximate peak storage deliverability utilization was 82% in December 2013. The Pacific region is comparably well

FIGURE 7.24 US natural gas storage capacity and utilization outlook.

TABLE 7.8 Historical Storage Utilization (2010
15). Working gas capacity (Bcf)

Max daily deliverability (Bcfd)

Max inventory level (Bcf)

Max inventory utilization

Approximate peak storage deliverability daya

Approximate peak storage deliverability day utilizationb

East

1080

24.5

960

89%

11.2

46%

Midwest

1233

28.4

1123

91%

19.3

68%

Mountain

450

3.7

235

52%

3.0

82%

Pacific

483

10.5

386

80%

8.3

79%

South central

1541

51.1

1327

86%

23.7

46%

Total US lower 48

4786

118.3

3939

82%

56.6

48%

a ICF first identified the highest withdrawal week for the period using EIA weekly withdrawal data. ICF then analyzed pipeline and storage operator publicly available data to identify the peak day withdrawal during the peak withdrawal week. b ICF then used the peak withdrawal quantity and applied it to the regions maximum daily deliverability capacity to obtain a peak day withdrawal utilization.

EIA, ABB Velocity Suite, ICF.

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utilized with a maximum inventory utilization of 80%, and an approximate peak storage deliverability utilization of 79%. The South Central region has a fairly wide range of inventory utilization with a maximum of 86%, and a peak storage deliverability utilization of 46%.

Source: From EIA, ICF

The East region has nearly all of its storage facilities located in the Appalachian Basin production region, which primarily spans Pennsylvania, New York, Ohio, and West Virginia. Nearly all of the region’s storage capacity and deliverability is comprised of depleted reservoirs. Several major markets in the East lack easy access to this storage, including New England, the Southeast, and Florida. Winter demand peak could become higher with cold weather in the region because of both residential and commercial demand, as well as demand for gas from the electric sector could increase as a response to cold weather conditions. This phenomenon was observed for the past two colder than normal winters. The region’s storage capacity has been heavily utilized in the past 5 years. There is no underutilized storage capacity that could offer additional flexibility. All the East region prices

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exhibit relatively pronounced seasonality, but only limited storage expansion opportunities exist. Recent working gas capacity additions have mostly been concentrated in the Marcellus production regions in Pennsylvania, West Virginia, and Ohio. Natural gas infrastructure, including storage capacity, might become constrained during the winter season, resulting in price spikes and extreme price volatility. Additional pipeline infrastructure to important market centers might be needed for the market to take advantage of supplies from production or storage. As the region’s reliance on natural gas-fired power generators grows to replace retired facilities using coal or oil, the location of these facilities will need to be optimized to consider their proximity to production, storage facilities, or population centers. There is sufficient natural gas storage capacity in Midwest to meet the region’s seasonal demand needs under a wide range of weather conditions. The extreme cold weather in the 2013
14 winter represents a 1 in 66-year occurrence, with less than 2% probability. The region’s access to a wide range of supply sources provides a diversified hedging portfolio for filling up the regions’ storage facilities. The seasonal withdrawal and injection patterns are expected to continue as LDCs in the region continue to use storage as an important supply source to meet winter customer needs, even with incremental pipeline capacity from the Marcellus/Utica production region. There is sufficient natural gas storage capacity in South Central to meet the region’s modest demand seasonality as well as the higher winter gas requirements from the export markets. The salt dome storage facilities in the region are currently underutilized. The primary entities using the salt dome storage are marketers and gas trading companies, and recent low natural gas prices and low price volatility have squeezed the potential profit margin from trading these assets. The quick turn, flexible salt dome storage capacity could become important service providers for load flowing to power plants that require intraday quick start-up or ramp down due to electric load profile and backing up renewable generation, as well as LNG facilities that could facilitate globally trading opportunities. Storage capacity is underutilized in the Mountain region. On an average year, natural gas inventory volumes do not exceed 50% of existing working gas capacity. Sufficient production and pipeline capacity exist to meet seasonality of regional demand. Rocky mountain gas has been driven out of the Midwest and East markets by the production growth from the Marcellus/Utica shale. The Pacific Northwest market lacks strong demand growth for natural gas or strong seasonality for winter peak needs. If power generation will be the growth engine of future demand, the physical capabilities of regional storage facilities need to be enhanced to help power plants with intra-day load following services or support quick start gas generation as backup for renewable resources. Storage capacity is sufficient to meet the market needs in the Pacific region. Maximum storage fill in the past 5 years only reached less than 80% of existing working gas capacity. Maximum withdrawals only reached approximately 60% of the maximum deliverability. The shrinking differential between summer and winter demand peaks indicates a dualpeak seasonal pattern of demand in the region. As a result, storage operation may not strictly follow a seasonal pattern. Frequent summer withdrawals and winter injections are required. August, and, to a lesser extent, July are becoming peak demand months that require net storage withdrawals to meet power demand needs. Storage owned by SoCal gas is more

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actively used than storage operated by PG&E as Northern California has more supply flexibility from pipeline imports and independent storage facilities. Independently operated storage facilities provide more flexibility and respond more quickly to daily demand fluctuations. Daily storage operations of these facilities have increasingly become nonseasonal in nature. Storage facilities may become crucial following the intra-day electric load fluctuations during the peak summer months of July and August.

7.4.8 Regional prices The representative gas prices over the past 5 years in each storage region are shown in Fig. 7.25. The East region is represented by three different price points, representing Northeast production, and Northeast and Southeast markets. The South Central, Mountain, and Pacific markets (represented by Henry Hub, Opal, and SoCal Border respectively) remain fairly stable throughout the period, with Opal and SoCal border peaking above $20/MMBtu in February of 2014. These regions all have underutilized storage capacities and this is reflected in their price history. In contrast, the Northeast and Southeast market prices (represented by Transco Z6-NY and Transco Z5 respectively) consistently spike during winter months and peaked in January 2014 above $120/MMBtu, surpassing $30/MMBtu on several days during that winter. The production area of the East, represented by Dominion South Point remained stable throughout the period, including peak winter demand seasons—even during the 2013
14 winter when it rose to only $8.63/MMBtu.

FIGURE 7.25

Representative regional prices—historical.

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FIGURE 7.26 Representative daily regional prices—winter 2013
14.

The Midwest region’s representative price point (Chicago City-Gates) shows a more modest trend, with exceptional peaks during winter months but not nearly as high as Eastern markets. The Midwest has ample storage capacity that is largely underutilized and therefore it stands to reason that its markets were less constrained than that of the East during the 2013
14 winter (Fig. 7.26). US Natural Gas Storage Capacity and Utilization Outlook

7.4.9 Value of storage and storage capacity additions A number of metrics are used to define and measure the volume of an underground storage facility: 1. Total gas storage capacity. It is the maximum volume of natural gas that can be stored at the storage facility. It is determined by several physical factors such as the reservoir volume, and also on the operating procedures and engineering methods used. 2. Total gas in storage. It is the total volume Of gas in storage at the facility at a particular time. 3. Base gas (also referred to as cushion gas). It is the volume of gas that is intended as permanent inventory in a storage reservoir to maintain adequate pressure and deliverability rates throughout the withdrawal season. 4. Working gas capacity. It is the total gas storage capacity minus the base gas. 5. Working gas. It is the total gas in storage minus the base gas. Working gas is the volume of gas available to the marketplace at a particular time. 6. Physically unrecoverable gas. The amount of gas that becomes permanently embedded in the formation of the storage facility and that can never be extracted. 7. Cycling rate. It is the average number of times a reservoir’s working gas volume can be turned over during a specific period of time. Typically the period of time used is 1 year. 8. Deliverability. It is a measure of the amount of gas that can be delivered (withdrawn) from a storage facility on a daily basis. It is also referred to as the deliverability rate,

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withdrawal rate, or withdrawal capacity and is usually expressed in terms of millions of cubic feet of gas per day that can be delivered. 9. Injection capacity (or rate). It is the amount of gas that can be injected into a storage facility on a daily basis. It can be thought of as the complement of the deliverability. Injection rate is also typically measured in millions of cubic feet of gas that can be delivered per day. The measurements above are not fixed for a given storage facility. For example, deliverability depends on several factors including the amount of gas in the reservoir and the pressure, etc. Generally, a storage facility’s deliverability rate varies directly with the total amount of gas in the reservoir. It is at its highest when the reservoir is full and declines as gas is withdrawn. The injection capacity of a storage facility is also variable and depends on factors similar to those that affect deliverability. The injection rate varies inversely with the total amount of gas in storage. It is at its highest when the reservoir is nearly empty and declines as more gas is injected. The storage facility operator may also change operational parameters. This would allow, for example, the storage capacity maximum to be increased, the withdrawal of base gas during very high demand or reclassifying base gas to working gas if technological advances or engineering procedures allow.

7.4.9.1 Depleted gas reservoir These are the most prominent and common forms of underground storage of natural gas. They are the reservoir formations of natural gas fields that have produced all or part of their economically recoverable gas. The depleted reservoir formation should be readily capable of holding sufficient volumes of injected natural gas in the pore space between

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grains (via high porosity), of storing and delivering natural gas at sufficient economic rates (via high permeability) and be contained so that natural gas cannot migrate into other formations and be lost. In addition, the rock (both the reservoir and the seal) should be capable of withstanding the repeated cycle of an increase in pressure when natural gas is injected into the reservoir and in reverse the drop in pressure when natural gas is produced. Using such a facility that meets the above criteria is economically attractive because it allows the re-use, with suitable modification, of the extraction and distribution infrastructure remaining from the productive life of the gas field which reduces the startup costs. Depleted reservoirs are also attractive because their geological and physical characteristics have already been studied by geologists and petroleum engineers and are usually well known. Consequently, depleted reservoirs are generally the cheapest and easiest to develop, operate, and maintain of the three types of underground storage. In order to maintain working pressures in depleted reservoirs, about 50% of the natural gas in the formation must be kept as cushion gas. However, since depleted reservoirs were previously filled with natural gas and hydrocarbons, they do not require the injection of gas that will become physically unrecoverable as this is already present in the formation. This provides a further economic boost for this type of facility, particularly when the cost of gas is high. Typically, these facilities are operated on a single annual cycle; gas is injected during the off-peak summer months and withdrawn during the winter months of peak demand. A number of factors determine whether or not a depleted gas field will make an economically viable storage facility: (Fig. 7.27). 1. The reservoir must be of sufficient quality in terms of porosity and permeability to allow storage and production to meet demand as required. 2. Natural gas must be contained by effective seals otherwise there will be lost volumes that cannot be recovered. 3. The depleted reservoir and field infrastructure must be close to gas markets. 4. The existing infrastructure must be suitable for retrofitting the equipment to inject and produce gas at the necessary pressures and rates.

Working Gas Capacity by Storage Facility Type

10%

4%

Depleted Reservoir Aquifer Reservoir Salt Formation 86%

FIGURE 7.27 Gas capacity by storage facility type.

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Aquifers are underground, porous, and permeable rock formations that act as natural water reservoirs. In some cases, they can be used for natural gas storage. Usually, these facilities are operated on a single annual cycle as with depleted reservoirs. The geological and physical characteristics of aquifer formation are not known ahead of time and a significant investment has to go into investigating these and evaluating the aquifer’s suitability for natural gas storage (Table 7.9). If the aquifer is suitable, all of the associated infrastructures must be developed from scratch, increasing the development costs compared to depleted reservoirs. This includes installation of wells, extraction equipment, pipelines, dehydration facilities, and possibly compression equipment. Since the aquifer initially contains water, there is little or no naturally occurring gas in the formation and of the gas injected some will be physically unrecoverable. As a result, aquifer storage typically requires significantly more cushion gas than depleted reservoirs, upto 80% of the total gas volume. Most aquifer storage facilities were developed when the price of natural gas was low, meaning this cushion gas was inexpensive to sacrifice. With rising gas prices, aquifer storage becomes more expensive to develop. A consequence of the above factors is that developing an aquifer storage facility is usually time-consuming and expensive. Aquifers are generally the least desirable and most expensive type of natural gas storage facility (Picture 7.5). LNG facilities provide delivery capacity during peak periods when market demand exceeds pipeline deliverability. LNG storage tanks possess a number of advantages over TABLE 7.9 Location of gas storage operations. Gas storage facility operations Type

Cushion gas

Injection period (days)

Withdrawal period (days)

Depleted reservoir

50%

200
250

100
150

Aquifer reservoir

50%
80%

200
250

100
150

Salt formation

20%
30%

20
40

10
20

From https://en.wikipedia.org/wiki/Natural_gas_storage#cite_note-Source2-5.

PICTURE 7.5 A liquefied natural gas storage tank in Massachusetts.

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underground storage. As a liquid at approximately 2163 C (2260 F), it occupies about 600 times less space than gas stored underground, and it provides high deliverability at very short notice because LNG storage facilities are generally located close to market and can be trucked to some customers avoiding pipeline tolls. There is no requirement for cushion gas and it allows access to a global supply. LNG facilities are, however, more expensive to build and maintain than developing new underground storage facilities.

7.4.10 Pipeline capacity Gas can be temporarily stored in the pipeline system, through a process called line packing. This is done by packing more gas into the pipeline by increasing the pressure. During periods of high demand, greater quantities of gas can be withdrawn from the pipeline in the market area than injected at the production area. This process is usually performed during off-peak times to meet the next day’s peaking demands. This method provides a temporary short-term substitute for traditional underground storage. 7.4.10.1 Gasholders An older column-guided gasholder and 1960s-built spiral-guided gasholders have been shown in Picture 7.6. Gas can be stored above ground in a gasholder (or gasometer), largely for balancing, not long-term storage, and this has been done since Victorian times. These store gas at district pressure, meaning that they can provide extra gas very quickly at peak times. Gasholders are perhaps most used in the United Kingdom and Germany. There are two kinds of gasholder—column guided, which are guided up by a large frame that is always visible, regardless of the position of the holder; spiral guided, which have no frame and are guided up by concentric runners in the previous lift. Perhaps the most famous British gasholder is the large column-guided “Oval gasholders” that overlooks The Oval cricket ground in London. Gasholders were built in the United Kingdom from early Victorian times; many, such as Kings Cross in London and St. Marks PICTURE 7.6

An older column-guided gasholder in West Ham, London.

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TABLE 7.10 Ownership of various types of pipelines. Underground natural gas storage by type of owner, 2005. Type of owner

Number of sites

Working gas capacity (109 ft3)

Daily deliverability (106 ft3)

Interstate Pipeline

172

2197

35,830

Intrastate & LDC

148

1292

33,121

Independent

74

521

14,681

Street in Kingston upon Hull are so old that they are entirely riveted, as their construction predates the use of welding in construction. The last to be built in the United Kingdom was in 1983. 7.4.10.2 Independent storage service providers The deregulation activity in the underground gas storage arena has attracted independent storage service providers to develop storage facilities (Table 7.10). The capacity made available would then be leased to third-party customers such as marketers and electricity generators. It is expected that in the future, this group would take more market share, as more deregulation takes place. Currently, in the United States, this group accounts for 18% of overall storage deliverability and 13% of working gas capacity in the United States. 7.4.10.3 Global storage capacity At the end of 2020, there were 661 UGS facilities in operation in the world. The global working gas capacity—423 billion cubic meters (bcm)—remains almost unchanged compared to the previous year and is equivalent to 11% of the global gas demand. Global market is dominated by a few countries: the United States, Russia, Ukraine, Canada, and Germany account for almost 70% of worldwide capacities. Storage in porous formations (depleted fields and aquifers) dominates with 91% of global working gas volumes, but salt caverns account for 26% of global deliverability. A renewed interest in UGS is reflected in the fact that 17% more projects cropped up in 2020 than in 2019. More and more governments around the world recognize the key role of UGS in providing security of supply, managing flexibility, optimizing production and grid operations, and dampening price variations and volatility. There are now 68 storage projects under construction in the world, adding 48 bcm of working gas capacity. All regions but Africa participate in the construction activity. China alone is expected to contribute around half of the total global capacity additions by 2025 (Fig. 7.28). Since 2018, the construction of natural gas storage infrastructure has been upgraded to a national policy. In March 2018, the National Development and Reform Commission required gas suppliers, city gas distributors, and local governments to have storage capacity equal to 10%, 5%, and 3 days of their annual sales or consumption, respectively, by the end of 2020. China has speeded up the building of storage facilities since 2018 and several new facilities were opened in 2021. During the 13th Five-Year Plan (2016
20), the working gas capacity of UGS grew by 160% to 14.5 bcm in 2020.

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FIGURE 7.28 Global gas storage capacity (Cedigaz, 2021).

In Russia, the replenishment of domestic UGS was a national priority in 2021 after an exceptionally harsh and long winter 2020/2021 fully depleted UGS stocks. The pressure exerted by the need to replenish domestic UGS has undoubtedly restricted gas export capabilities: 21% of Gazprom production was pumped into storage during April
October 2021. UGS active working gas capacity reached 72.6 bcm at the beginning of November 2021.

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C H A P T E R

8 Fundamental considerations of oil and gas separation 8.1 Introduction Crude oil is a complex mixture of oil, gas, water, and solids in suspension. Because the in situ pressure and temperature conditions are quite different from atmospheric conditions, the produced crude oil remains in a state of flux. As such the first task in hand is to bring the fluid to an equilibrium state from where different phases can be separated. Reactive distillation (RD) is one of the best success stories of process intensification technology. Nowadays, RD is considered an established industrial unit operation, being the front-runner in the PI field with more and more applications reported in the literature. RD relies on the synergy generated when combining catalyzed reactions and distillation into a single unit. But, as both operations take place in the same unit at the same time, there must be a good match between the operating parameters required for reaction and distillation. This overlap is usually limited by the properties of the components (e.g., boiling points), catalytic activity and selectivity, and equipment design, among others. Usually, this leads to a restricted area in which RD is actually feasible, being a trade-off as shown in Fig. 8.1. Fig. 8.1 shows how the RD process starts with the separation process. As fluid flows from high temperature, high pressure conditions to atmospheric pressure, the following factors play a role: • • • • • • • •

Gas and liquid flow rates. Operating pressures and temperatures. Fluctuations in flow rates. Properties of the fluids. Separation operating conditions. Presence of paraffin, asphaltene, sand, scales, etc. Foaming and frothing tendencies. Overall gas
oil and water
oil ratios.

Three governing principal dictate the separation process: momentum, gravity, and coalescence (Mokhatab and Poe, 2012). These principles are handled with theories that are

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8. Fundamental considerations of oil and gas separation

FIGURE 8.1 RD requires an overlap of the operating windows for reaction and separation. The star symbols illustrate cases where standalone separation and reaction are preferred, while the plus indicates a match for RD (Kiss et al., 2019).

FIGURE 8.2

Separation in a horizontal separator.

centuries old but remain useful. With those principles, separators, gas processing units, etc. are designed. In this chapter, fundamentals of these theories are reviewed and their shortcoming is highlighted.

8.2 Gravity separation Gravity separation is carried out in pressure vessels, in which fluid stream is decompressed to allow water, oil, and gas to segregate based on gravity. Fig. 8.2 shows how gravity separators allow separation of solids, water, oil, and gaseous droplets. The gas droplet sizes depend on the flow rate and gas
oil ratio (GOR) of the effluent. The efficiency of the separation increases if the flow rate is lowered. It is because gravity separation cannot take place instantaneously. Depending on the liquid’s source, the particle size can be large enough to be seen by the naked eye (greater than 10 microns) or small enough (1 micron or less) to be seen only

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by light diffusion. Talavera (1990) discussed separator selection, which cannot be made until the droplet size distribution range is defined, and showed the diameter range of various types of particles. Stream sampling is often not possible so that a knowledge of the process and the required process specifications are often the basis for design of most mist collection equipment. Process constraints such as pressure drop, turndown, liquid loading, droplet size, corrosion, and fouling potential usually dictate the required internals in separator vessels. Because of the large vessel size required to achieve settling, gravity separators are rarely designed to remove droplets smaller than 250 mm (Talavera, 1990). Very small droplets such as fog or mist cannot be separated practically by gravity. However, they can be coalesced to form larger droplets that will separate out. Coalescing devices in separators force gas to follow a tortuous path. The momentum of the droplets causes them to collide with other droplets or with the coalescing device, forming larger droplets. These can then separate out of the gas phase due to the influence of gravity. Wire mesh screens, vane elements, and filter cartridges are typical examples of coalescing devices. Of these vane separators are common. Vane separators employ vane technology that consists of closely spaced metal plates that form a serpentine flowpath. Specially designed flow channels trap collected liquids and allow them to drain without having to flow across the gas stream, or against it. In its basic configuration, the vane separator offers the most compact and cost effective utilization of vane technology. Other than a drain box at the base of the vane bundle, there are no other internal components. An amount of time is needed to assure that the liquid and gas reach equilibrium at separator. The time is defined as “retention time” or the average time a molecule of liquid is retained in the vessel assuming plug flow. Gravity separators are often classified by their geometrical configuration (vertical, horizontal) and by their function (two-phase/three-phase separator). Here, two phase implies oil and gas and three phase implies oil, gas, and water. Horizontal separators are almost always used for high GOR wells, for foaming well streams, and for liquid
liquid separation. This is because, horizontal separators would allow longer retention time for high GOR cases. Fig. 8.3 shows a typical scheme of a threephase horizontal separator. The fluid enters the separator and hits an inlet diverter. This sudden change in momentum generates the initial bulk separator of liquid and gas. In most designs, the inlet diverter contains a downcomer that directs the liquid flow below the oil
water interface. This forces the inlet mixture of oil and water to mix with the water continuous phase in the bottom of the vessel and rise through the oil
water interface. This process called “waterwashing” promotes the coalescence of water droplets that are entrained in the oil continuous phase. The inlet diverter assures that little gas is carried with the liquid, and the water
wash assures that the liquid does not fall on top of the gas
oil or oil
water interface, mixing the liquid retained in the vessel and making control of the oil
water interface difficult. The liquid-collecting section of the vessel provides sufficient time so that the oil and emulsion form a layer or oil pad at the top. The free water settles to the bottom. Any sand or solid that might be in the effluent drops off at the bottom of the separator. The produced water flows from a nozzle in the vessel located upstream of the oil weir. An interface level controller sends a signal to the water dump valve, thus allowing the correct amount of water to leave the vessel so that the oil
water interface is maintained at the

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FIGURE 8.3 Schematic of a horizontal well separator.

design height. The gas flows horizontally and outs through a mist extractor (normally known as a demisting device) to a pressure control valve that maintains constant vessel pressure. The level of gas
oil interface can vary from half (50%) of the diameter to 75% of the diameter depending on the relative importance of liquid
gas separation and what purpose the separator has. Separators can also be categorized according to their operating pressure. Low-pressure units handle pressures of 10
180 psi. Medium-pressure separators operate from 230 to 700 psi. High-pressure units handle pressures of 975
1500 psi. Four major functional zones can be generally identified in the horizontal three-phase separator (Steward and Arnold, 2008). These are as follows: • Primary separation zone: This is the section between the inlet nozzle and first baffle, which is desired to separate the bulk liquid from the gas stream. • Gravity settling zone: It is downstream from the primary separation zone. It is used for the entrained droplets to settle from the wet gas stream. This section normally occupies a large portion of the vessel volume through which the gas moves at a relatively low velocity. • Droplet coalescing zone: This zone follows the gravity settling zone that could be equipped with parallel plates, vane packs, mesh pads, and spiral flow. This zone helps to remove very small droplets based on impingement and inertial separation principles. • Liquid collection zone: This last section may have a certain amount of surge volume over a minimum liquid level necessary for control system to function properly. However, the most common configuration is half full. A vertical separator can handle relatively large liquid slugs without carryover into the gas outlet. It thus provides better surge control, and is often used on low to intermediate GOR wells and wherever else large liquid slugs and more sands are expected.

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They are available for two-phase and three-phase operations. They also vary in size (in diameter and height). Fig. 8.4 shows a typical scheme of a three-phase vertical separator. The flow enters the vessel through the side as in the horizontal separator and the inlet diverter separates the bulk of the gas. The gas moves upward, usually passing through a mist extractor to remove suspended mist, and then the dry gas flows out. Horizontal separators are normally preferred over vertical separators due to the flow geometry that promotes phase separation. In the vertical separator, the separation between oil and gas is enhanced by gravity, thus reducing the retention time. This leads to dragging oil into the gas droplets, which are difficult to detach. However, vertical separators are sometimes selected because of the advantage due to space requirements. For instance, vertical separators are viable options for offshore operations, where the space limitations are on the production platform. The produced fluid stream enters the separator from the side and hits the inlet diverter, where the bulk separation of the gas from the liquid takes place. The gas flows upward through the gravity settling sections which are designed to allow separation of liquid droplets down to a certain minimum size (normally 100 mm) from the gas. The gas then flows through the mist extractor, where the smaller liquid droplets are removed. The gas leaves the separator at the top through a pressure control valve that controls the separator pressure and maintains it at a constant value. The liquid flows downward through a downcomer and a flow spreader that is located at the oil
water interface. As the liquid comes out of the spreader, the oil rises to the oil pad and the water droplets entrapped in the oil settle down and flow, countercurrent to the rising oil phase, to collect in the water collection section at the bottom of the separator. The oil flows over a weir into an oil chamber and out of the separator through the oil outlet valve. A level controller controls the oil level in the chamber and operates the oil outlet valve. Similarly, the FIGURE 8.4 Schematic of vertical separator.

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water out of the spreader flows downward into the water collection section, whereas the oil droplets entrapped in the water rise, countercurrent to the water flow, into the oil pad. An interface controller that operates the water outlet valve controls the water level. The use of the oil weir and chamber in this design provides good separation of water from oil, as the oil has to rise to the full height of the weir before leaving the separator. The oil chamber, however, presents some problems. First, it takes up space and reduces the separator volume needed for the retention times of oil and water. It also provides a place for sediments and solids to collect, which creates cleaning problems and may hinder the flow of oil out of the vessel. In addition, it adds to the cost of the separator. Liquid
liquid interface controllers will function effectively as long as there is an appreciable difference between the densities of the two liquids. Under certain conditions, oil will separate from water because of the difference in specific gravity between the two fluids. Stoke’s law explains the rate at which oil is separated from a lighter liquid, and this formula helps determine how fast an oil droplet will rise or settle, based on the following factors: • • • •

Density and size of the oil droplet. Distance the object must travel. Size of the collection tank. Flow rate.

An oil/water separator is designed to consider these factors and subsequently assists in creating the ideal conditions needed for oil to separate from water. There are two primary types of oil/water separators: gravity separators, like API oil/water separators, and coalescing separators.

8.2.1 Types of oil/water separators Fig. 8.5 shows a schematic of a typical separator. 8.2.1.1 Gravity oil/water separators or API separators This type of industrial oil/water separator relies on the difference between the gravity of water and the specific gravities of oils, operating as follows:

1

Oily Water Inlet

FIGURE 8.5 Gravity oil/

Gravity oil/water separator

water separator.

Oil Layer “Clean” Water Outlet

Seled Solids

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Oil Outlet

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2

FIGURE

8.6 Coalescing oil/water separators.

Coalescing oil/water separator Oil Layer

Oily Water Inlet

“Clean” Water Outlet

Seled Solids

Oil Outlet

• Oily water enters the inlet of the separator. • Water turbulence is reduced when it meets a baffle and most solids settle to the bottom of the separator. • As wastewater flows through the oil/water separator, oil droplets float to the top of the water but are prevented from exiting the separator by a second baffle; any remaining solids settle (Fig. 8.6). 8.2.1.2 Coalescing oil/water separators With coalescing separators, the general flow of oil and water through the separator is similar to a gravity separator. However, in a coalescing separator, oil and water also flow through oleophilic media. This extra step allows the oil droplets to bind together on the surface of the media. By coalescing or binding together, the oil droplets become larger and more buoyant, thus rising to the surface more quickly and further enhancing separation.

8.2.2 Benefits of an oil/water separator With a properly designed oil/water separator in place, facilities with oily process water or wastewater are able to effectively separate oil from water before reusing or discharging clean water to the sewer or back into the environment. With the right separator design, made to accommodate the conditions and of your particular application, you can expect the following benefits: • Improved oil removal: When oily water is provided sufficient time and space to effectively separate into two distinct layers, with the oil floating freely on the surface of that water, an oil skimmer can remove the oil with much more ease and efficiency. • Improved wastewater treatment: When oil is separated and removed from wastewater prior to chemical treatment or filtration, treatment processes are more effective and filtration equipment lasts longer and performs better. • Environmental compliance: Oil and water separators lead to cleaner wastewater that meets the requirements of local and federal regulations.

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• Reduced maintenance: When the right oil/water separator tank is specified and meets the challenges of the application, efficient oil separation and removal is achieved, which means less maintenance is required to keep the separator running, and downstream treatment equipment will perform more effectively. • Potential revenue generator: In some cases, reclaimed oil can be sold as a valuable commodity. In most three-phase separator applications, water
oil emulsion forms and a water
emulsion interface will be present in the separator instead of a water
oil interface. The density of the emulsion is higher than that of the oil and may be too close to that of the water. Therefore, the smaller density difference at the water
emulsion interface will adversely affect the operation of the interface controller. The presence of emulsion in the separator takes up space that otherwise would be available for the oil and/or the water. This reduces the retention time of the oil and/or water and, thus results in a less efficient oil
water separation. In most operations where the presence of emulsion is problematic, chemicals known as demulsifying agents are injected into the fluid stream to mix with the liquid phase. Another method that is also used for the same purpose is the addition of heat to the liquid within the separator. In both cases, however, the economics of the operations have to be weighted against the technical constraints (Table 8.1).

TABLE 8.1 Difference between horizontal and vertical separators. Horizontal

Vertical

Horizontal separators are most commonly used in the following conditions:

These separators are used in the following conditions:

• • • •

Large volumes of gas and/or liquids High-to-medium gas/oil ratio (GOR) streams Foaming crudes Three-phase separation

• Small flow rates of gas and/or liquids. • Very high GOR streams or when the total gas volumes are low. Advantages are as follows:

• Liquid-level control is not so critical. The advantages and disadvantages of these separators are as follows:Advantages are as follows: • Have good bottom-drain and clean-out facilities. • Can handle more sand, mud, paraffin, and wax without • Require smaller diameter for similar gas capacity plugging. as compared to vertical vessels. • Less tendency for reentrainment. • Have full diameter for gas flow at top and oil flow at • No counterflow (gas flow does not oppose bottom. drainage of mist extractor). • Large liquid surface area for foam dispersion • Occupy smaller plot area. generally reduces turbulence. Disadvantages are as follows: • Larger surge volume capacity. Disadvantages are as follows: • • • •

Only part of shell available for passage of gas. Occupy more space unless “stack” mounted. Liquid-level control is more critical. More difficult to clean produced sand, mud, wax, paraffin, etc.

• Require larger diameter for a given gas capacity, therefore, most competitive for very low GOR or very high GOR or scrubber applications. • They are not recommended when there is a large slug potential. • More difficult to reach and service top-mounted instruments and safety devices.

From Mokhatab and Poe (2012).

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8.3 Oil
water separation Important considerations in this process of separation within a separator are as follows: • Separation of liquid droplets from the gas phase, which determined the gas capacity constraint, is exactly the same for three-phase separators. • Separation between oil and water. • Separation between solid and liquid (emulsion or sludge). An important aspect of separator design is the retention time, which determines the required liquid volumes within the separator. The oil phase needs to be retained within the separator for a period of time that is sufficient for the oil to reach equilibrium and liberates the dissolved gas. The retention time should also be sufficient for appreciable coalescence of the water droplets suspended in the oil to promote effective settling and separation. Similarly, the water phase needs to be retained within the separator for a period of time that is sufficient for coalescence of the suspended oil droplets. The retention times for oil and water are best determined from laboratory tests; they usually range from 3 to 30 minutes, based on operating conditions and fluid properties. If such laboratory data are not available, it is a common practice to use a retention time of 10 minutes for both oil and water. The liquid retention time constraint was the only criterion used for determining the liquid capacity of two-phase separators. For three-phase separators, however, the settling and separation of the oil droplets from water and of the water droplets from oil must be considered in addition to the retention time constraint. Further, the retention time for both water and oil, which might be different, must also be considered. In separating oil droplets from water, or water droplets from oil, a relative motion exists between the droplet and the surrounding continuous phase. An oil droplet, being smaller in density than the water, tends to move vertically upward under the gravitational or buoyant force, that the droplet settling velocity is inversely proportional to the viscosity of the continuous phase. Many oil
water separation methods like adhesion, gravity separation, absorbance, membrane filtration, and chemical and biological treatments have been developed over the years and most of these techniques are widely used (Gondal et al., 2014). However, achieving an oil
water separator with low power consumption and high separation efficiency is still a great challenge. Since immiscible oil
water mixtures are governed by interfacial phenomenon, an effective method for the separation can be provided by selecting or synthesizing a material with preferential wetting toward oil or water. For materials that are hydrophobic
oleophilic materials, the water contact angle (denoted θwa) is greater than 90 degrees and the oil contact angle (θoa) is less than 90 degrees, and this makes filters constructed from such materials nonwettable by water and wettable by oil. When hydrophobic
oleophilic materials are used as the oil pass filters in oil
water separation, they easily get fouled by viscous oil residues and hence cannot be used for large-scale separation methods (Zhou et al., 2013). In order to separate oil from water
oil mixture, membrane technologies have been used.

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The two most prominent membrane filtering techniques employed for oil
water separation are gravity-driven and cross-flow filtration. Of these two methods, the gravity-driven method is preferred due to the much lower cost and higher permeate collection rate, compared to cumbersome and expensive cross-flow filtration systems (Hu and Scott, 2007). The ideal filter surface for gravity-driven filtration is a counterintuitive hydrophilic
oleophobic structure or the more efficient superhydrophilic
superoleophobic surfaces. Since the surface tension of water is greater than that of oil, materials with this kind of wettability are technically more difficult to fabricate and this mechanism often involves superomniphobic materials (θwa and θoa . 150 degrees), which can respond to external triggers to generate the superhydrophilicity (Kwon et al., 2012). Kota et al. (2012) reported hygroresponsive superhydrophilic
superoleophobic surfaces on meshes and fabrics, coated with fluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS) blended with poly(ethylene glycol) diacrylate (PEGDA). Fluorodecyl POSS has a very low surface energy (γ sv  10 mN/m), and hence it has been used in the construction of many liquid-repellent surfaces (Tuteja et al., 2007). However, fluorodecyl POSS is quite expensive, and in pure form, it has a poor adherence to the underlying substrate. Cao et al. (2008) reported oil repellency behavior on porous silicon film. Zhang et al. (2011) demonstrated superoleophobic surfaces on perfluorosilanerendered titania (TiO2)/single-walled carbon nanotube composite coatings, and upon further UV irradiation, these surfaces passed from the Cassie (Cassie and Baxter, 1944) to the Wenzel (1949) state and finally to the inverse Cassie regime. Oil
water separation can also be achieved using superhydrophilic materials that possess underwater superoleophobicity, that is, the respective contact angles are θwa , 5 degrees and θow . 150 degrees. In addition to this, photoinduced oil
water separation and selfcleaning ability from fouling have also been demonstrated to be important in the separation performance (Xue et al., 2011). Various preparation methods such as layer-by-layer coating, polymerization, sol
gel method, hydrothermal treatments, direct oxidation, and chemical vapor deposition have been employed, and various materials such as hydrogel, silicate, TiO2, silica gel, zeolite, and nanostructured ZnO surfaces have been studied in order to achieve superhydrophilic surface with good underwater
oil repellency (Xue et al., 2011). However, most of these preparation methods involve multiple processes, long and delicate methods of sample preparation, exotic materials, and extreme physical conditions to achieve a surface with such wetting properties. In the case of cold spray coating method, the coating application is carried out at ambient temperatures that are much lower than the melting point of the substrate material. Consequently, undesirable thermal factors like oxidation, thermal degradation, and unwanted formation of defects on the coated surface can be minimized. Also in the cold spray coating, the deposited material is accelerated at very high velocity with the help of compressed gas and this can enable spray droplets to undergo an extreme and rapid plastic deformation on impact, thereby, compressing and conformally coating a layer of material on the substrate. Because of the large generation of interfacial area and the rapid drying of the volatile carrier/solvent, the sprayed deposits are typically rough or nonuniform in texture. Because surface roughness is one of the major factors controlling the hydrophilicity of the surface, with this cold spray deposition method, the surface roughness values of the resulting films can be tuned by controlling the amount of deposited TiO2 nanoparticles on the mesh.

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Gondal et al. (2014) fabricated superhydrophilic surfaces that exhibit underwater superoleophobicity by the spray coating of nanostructured TiO2 on stainless steel mesh. This method of fabrication is not only rapid, simple, and cost-effective but also the coated mesh shows an excellent water affinity and strong underwater
oil repellency. The coated meshes are characterized by SEM, XRD, and contact angle goniometry. The superhydrophilic and underwater superoleophobic TiO2 coated mesh was used for the gravity-driven oil
water separation experiments and showed 99% oil
water separation efficiency by letting water pass through the mesh and retaining the oil above the mesh. The adsorbed layer of water on the coated surface, formation of a water film between the individual wires of the mesh, and the strength of the underwater superoleophobicity all contribute to this enhanced efficiency of oil
water separation. It should be noted that the TiO2 coated mesh and TiO2 coated glass discussed in Fig. 8.7 were annealed, whereas the uncoated mesh was not annealed. Fig. 8.7 compares the values of θow measured for five different oils on three different surfaces, mentioned above, and it is evident that the TiO2 coating significantly improves the oil repellency of the stainless steel mesh invariably for all the oil samples under study. The average value of θow for the oil samples listed above on a TiO2 coated stainless steel mesh is 164 6 6 degrees, which is comparable with the oil-in-water contact angle of TiO2 coated glass substrate for the same oil samples under study. Also, the sliding angle for the TiO2 coated mesh is very small while for the uncoated mesh, surface pinning dominates and no sliding angle could be observed even for 30 degrees inclination (see Fig. 8.7). Pictorial views of the oil
water separation system developed for this study are shown in Fig. 8.8, along with SEM images of coated and uncoated stainless steel meshes with 100 μm pore sizes. The oil
water mixture is poured into the top glass tube, and the permeate is collected in a beaker placed underneath the bottom tube. In order to understand the critical role of TiO2 coating on the stainless steel mesh, we first used a thermally annealed but uncoated stainless steel mesh in between the glass tubes and found that both

FIGURE 8.7 Contact angle measurement of oil drops immersed in a water environment. Different alkanes were tested on an uncoated mesh (first bar from left), TiO2 coated mesh (second bar), and a flat TiO2 coated glass substrate (third bar from left).

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FIGURE 8.8 Oil
water separation setup facility developed in our laboratory. Photograph of separation result using (A) annealed uncoated stainless steel mesh and (B) TiO2 coated stainless steel mesh with the same pore size (100 μm).

the oil and water permeated rapidly through the mesh as exhibited in Fig. 8.8A. On the other hand, when TiO2 coated stainless steel mesh was used in between the two tubes, the water in the oil
water mixture permeated through the coated mesh leaving the oil in the top glass tube as shown in Fig. 8.8B. In this oil
water separation system, they used TiO2 coated stainless steel meshes of four different pore sizes and tested three different oil
water mixture samples. The volume of the mixture used in each test was around 40 mL, and the separation took place within a few seconds. After the separation, the system was observed at rest for 5
10 minutes to check if any oil droplets permeated through the mesh. The oil
water separation efficiencies of all of the 12 combinations of oils and pore sizes are shown in Fig. 8.5, along with the SEM images of the meshes used. The oil
water separation efficiency was calculated using Eq. (8.1).  Cp 3 100% (8.1) Eff 5 1 2 Co where Co and Cp are the volume/volume ratios (v/v) of the original oil
water mixture and the filtered permeate, respectively. Co and Cp were determined by measuring the volume ratio of oil with respect to the mixture (oil and water) using a graduated cylinder. The value of Co used was 49% 6 6%. From Fig. 8.9, it is clear that the annealed TiO2 coated stainless steel mesh of 50 and 100 μm achieved 99% oil
water separation efficiency and a

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FIGURE 8.9 Measurement of the separation efficiency. Annealed TiO2 coated mesh with four different pore sizes was used to separate oil
water mixtures. The scale bar in the SEM images is 100 μm.

very small trace of oil was found in the permeate (water). However, the TiO2 coated stainless steel meshes of higher pore size showed poor oil
water separation efficiency. It is clear from this study that a spray coating on the 100 μm stainless steel mesh (contrary to traditional cumbersome coating procedures) can be applied very effectively for the oil
water separation. More viscous or heavier oil such as hexadecane and relatively lower viscosity (or “lighter”) oils like cyclohexane were tested for oil
water separation efficiencies. We found that the separationability is independent of the viscosity of the oil. However, the rate of permeation did decrease when more viscous oils were tested. The contact angle of oil droplet on a flat solid surface in water can be expressed using the Young
Dupre´ equation as written in Eq. (8.2). cos θow 5

γ sw 2 γ so γ cos θoa 2 γ wa cos θwa 5 oa γ ow γow

(8.2)

where γ sw and γ so are respectively solid/water and solid/oil interfacial tensions while γ oa, γ wa, and γ ow are the surface tension of oil, surface tension of water, and the interfacial tension of an oil
water interface, respectively. The value of θow becomes high when γ wa cos θwa is greater than the term γ oa cos θoa. Thus, underwater
oil repellency can be increased by increasing the hydrophilicity of the immersed solid surface. It is clear that the underwater superoleophobicity is an important factor for the oil
water separation process, but it is also apparent from our results in Fig. 8.8 that it is not a sufficient criterion for oil
water separation and that surface roughness is also a governing factor in the oil
water separation process. It is evident from Fig. 8.8A, that even though the annealed mesh exhibits underwater superoleophobicity, it failed in the oil
water separation. On the other hand, stainless steel meshes of same pore sizes (50 and 100 μm), when coated with TiO2, showed 99% efficiency in oil
water separation, confirming that superhydrophilicity and underwater
oil repellency alone are not the sufficient conditions for oil
water separation It can be seen from the SEM images of Fig. 8.8B that, compared to the smooth annealed stainless steel surface, the TiO2 coated mesh shows both micro and nanoscale roughness

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and this surface roughness contributes favorably for oil
water separation due to its increased underwater
oil repellency. Since annealed stainless steel is hydrophilic, the smooth surface is more favorably in contact with water, and this leads to high oil repellency. Defects on the solid surface can introduce pinning points that impact droplet mobility across the texture. Introducing a rough porous coating to the surface by covering it with TiO2 nanoparticles enables this superhydrophilic texture to trap water within the roughness. In addition to this, the strong affinity of TiO2 toward water molecules can create a surface-adsorbed water layer such that an oil droplet is not at all in contact with the liquid impregnated surface, which is confirmed by the low values of sliding angle, that are exhibited by TiO2 coated glass and TiO2 coated stainless steel mesh. Since the TiO2 surface is also wettable by oil, the TiO2 coated mesh must be prewetted by water before using it for oil
water separation. The presence of an adsorbed water layer on the porous TiO2 surface is an important factor for oil
water separation. This adsorbed water layer plays two distinct roles in oil
water separation: first, it prevents oil droplets from coming into contact with the mesh during the separation process; second, this layer provides channels for the water droplets from the oil
water mixture to permeate to the opposite side of the coated mesh. These necessary conditions for oil
water separation cannot be met by annealed stainless steel mesh due to its smooth surface texture, the low affinity toward water molecules, and the presence of pinning defects that trap oil droplet on the surface leading to fouling. Another factor which plays a major role in oil
water separation is the pore size of the mesh. We observed that oil
water separation did not yield a desirable result when the pore size of the stainless steel mesh is greater than 100 μm. However, if an oil droplet is carefully placed on top of the TiO2 coated mesh, the porous mesh can withstand the hydrostatic pressure of the oil column. At a certain critical height, hmax, the oil starts flowing downward and penetrating the TiO2 coated mesh. The intrusion pressure is expressed as a hydrostatic head, Pint 5 ρghmax, where ρ is the density of oil and therefore Pint can be calculated by measuring the height, hmax. As the hydrostatic pressure falls below the intrusion pressure, that is, after h , hmax, it is expected that the oil will stop flowing. Surprisingly, we find that once the oil starts flowing, it in fact keeps flowing until most of the oil phase is transferred to the other side of the mesh. The formation of a water film (capillary bridge) between the individual wires of the mesh is quite normal, because the pore size of the mesh is much smaller than the capillary length of water. This contiguous water film is found to be one of the most important factors that govern the oil
water separation. In view of this fact, we develop a simple model for the contact line of oil, water, and solid interfaces in the TiO2 coated mesh. Fig. 8.10A shows the formation of a uniform water film between the two wires of the mesh, separated by a distance d (pore size of the mesh). When this prewetted mesh is in contact with oil, the three-phase contact line adjusts in order to maintain the required underwater
oil contact angle, θow, as illustrated in Fig. 8.10B. From this, the intrusion pressure can be calculated using the Young
Laplace equation given in Eq. (8.3). Pint 5 2

2γ ow cos θow d

(8.3)

This intrusion pressure is the excess pressure required in the oil phase to overcome the interfacial tension at the interface. At the critical condition, the vertical components of

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FIGURE 8.10 Intrusion pressure and illustrated configuration of oil
water meniscus. (A) The formation of a water film in the pore of the mesh. (B) Contact line of oil and water in equilibrium state. (C) The contact line of oil and water under applied pressure. (D) Comparison of measured and calculated result of the intrusion pressure.

forces are balanced, ΣFy 5 FP 1 Fγ 5 0, where FP and Fγ are the force from external pressure and the force from the interfacial tension, respectively. This force balance can be established only if θow is larger than 90 degrees so that the vertical components of FP and Fγ are pointing in opposite directions. On the other hand, if θow is less than 90 degrees, there is no static force balance possible as FP and Fγ are pointing in the same direction. The positive value of Pint (when θow . 90 degrees) indicates that a hydrostatic pressure must be established in order to force the oil droplets into the mesh pores. Conversely, negative value of Pint (when θow , 90 degrees) indicates that the oil phase needs no external pressure to spontaneously penetrate through the mesh pores. The contact line illustrated in Fig. 8.10C shows the situation when the system is under an applied pressure. If the applied pressure is greater than the intrusion pressure, the oil phase will break the water film, resulting in a change in the shape of the interfacial line, and under this condition, Eq. (8.4) is no longer valid to describe the system. Consequently, γ ow and θow need to be substituted by γ oa and θoa respectively as the interface changed, where θoa is the contact angle of oil on water in air environment. The value of θoa can be calculated using the Young equation shown in Eq. (8.4). γ 2 γ ow cos θoa 5 wa (8.4) γ oa Numerical values for most of these parameters can be found in the literature. Since γ wa is generally larger than γ ow, the value of cos θoa is always positive. As a result, the intrusion pressure will have negative values and the oil phase will spontaneously channel down through the mesh. This is why we observed that the oil did not stop flowing after initial breakthrough is achieved, even when the hydrostatic pressure is reduced below the critical intrusion pressure.

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Fig. 8.10D depicts the plot of intrusion pressure versus γ ow/d. The measured value was determined by measuring the maximum hydrostatic pressure discussed earlier and the calculated value was obtained using Eq. (8.3). Fig. 8.10D indicates that the experimental value is statistically in agreement with the theoretical value. This result is important for selection of the correct pore size of mesh for oil
water separation. It is clear from Eq. (8.4) that the bigger the pore size, the smaller the intrusion pressure. If the intrusion pressure is small, the separation may fail as the impact force of the mixture fluctuates during the separation process. Oil viscosity is several magnitudes higher than the water viscosity for most crude oils. Therefore, the settling velocity of water droplets in oil is much smaller than the settling velocity of oil droplets in water. The time needed for a droplet to settle out of one continuous phase and reach the interface between the two phases depends on the settling velocity and the distance traveled by the droplet. In operations where the thickness of the oil pad is larger than the thickness of the water layer, water droplets would travel a longer distance to reach the water
oil interface than that traveled by the oil droplets. This, combined with the much slower settling velocity of the water droplets, makes the time needed for separation of water from oil longer than the time needed for separation of oil from water. Most commonly used water-treating equipment depends on the forces of gravity to separate the oil droplets from the water continuous phase (Stewart and Arnold, 2011). Oil droplets, being lighter than the volume of water they displace, have a buoyant force exerted upon them. This force is resisted by a drag force caused by their vertical movement through the water. When the two forces are equal, a constant velocity is reached, which can be computed from Stokes’ law as shown in Eq. (8.5). Vr 5



5:6 1027 ðΔS 1 GÞ μw

(8.5)

where Vr 5 rising velocity of the oil droplet, ft./s (m/s). d0 5 diameter of oil droplet, microns (μ). ΔSG 5 difference in specific gravity between oil and water, relative to water. μw 5 viscosity of the continuous water phase, cp. Stoke’s law is concerned with the drag force exerted on spherical object falling through a viscous fluid medium (Fig. 8.11). FIGURE 8.11

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The assumptions behind Stoke’s law are as follows: 1. 2. 3. 4.

The fluid is continuous. The flow is laminar. Newton’s law of viscosity holds. The terms involving velocity squared are negligible. Conclusions drawn from Stokes’ law are as follows: • The larger the size of an oil droplet, the larger the square of its diameter and, thus, the greater its vertical velocity will be. • The greater the difference in density between the oil droplet and the water phase, the greater the vertical velocity will be. • The higher the temperature, the lower the viscosity of the water and, thus, the greater the vertical velocity will be.

The minimum size of the water droplet that must be removed from the oil and the minimum size of the oil droplet that must be removed from the water to achieve a certain oil and water quality at the separator exit depend largely on the operating conditions and fluid properties. Because the conditions of Stoke’s law are rarely, if ever, met, results obtained from laboratory tests conducted under simulated field conditions provide the best data for design. The next best source of data could be obtained from nearby fields. If such data are not available, the minimum water droplet size to be removed from the oil is taken as 500 mm. The droplet sizes are a function of several factors, including crude oil acidity, salinity, suspended solid concentrations, and others. Table 8.2 gives such data on North Sea crude oil. Several factors, including chemical composition, phase composition, temperature, interfacial tension, and energy input during preparation exert an influence on the properties of obtained w/o emulsions. The most significant properties of water-in-oil emulsions are droplet size distribution (DSD) and mean droplet size of the emulsion. TABLE 8.2 Typical crude oil characteristics (North sea crude, reported by Kolotova et al., 2017). Characterization parameter

Content

Saturates (wt.%)

37.4 6 0.5

Aromatics (wt.%)

44.1 6 0.5

Resins (wt.%)

16.1 6 0.6

Asphaltenes (wt.%) (hexane-insoluble)

2.54 6 0.03

Emulsified water (wt.%)

0.06 6 0.01



Density (g/cm , 20 C)

0.934 6 0.001

Total acid number, TAN (mg KOH/g)

2.15 6 0.02

Total base number, TBN (mg/g)

2.81 6 0.04

3



317.5 6 0.1

a

Dynamic viscocity (mPa s, 20 C)

Determinated by the rotation viscosimetry technique at shear rate γ_ 5 100 s21.

a

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Fig. 8.12 shows droplet size distributions measured by nuclear magnetic resonance. NMR experiments are performed immediately after emulsion preparation. A mean droplet size distribution centered around 3 2 4 μm is observed for all emulsions prepared with 3.5 wt.% NaCl solution at 5 and 15 minutes, which is in quantitative agreement with images obtained by optical microscopy (Fig. 8.13). Images of water-in-crude oil emulsions prepared at various emulsification times are obtained at 50 3 amplification. Thermograms obtained during three DSC cycles of an emulsion sample are reported in Fig. 8.13. Thermograms obtained during three DSC cycles of an emulsion sample are reported in Fig. 8.13. The emulsions are prepared by homogenization for 5 or 15 minutes and contain 3.5 wt.% of NaCl in water. The emulsions are the water phase characterized by a water crystallization peak centered around 241 C to 242 C due to similar mean droplet diameters of all emulsions. It is confirmed that emulsification time does not have a significant impact on droplet size. This signal location is typical for the crystallization of small-sized (micron-scale) water droplets.

FIGURE 8.12 Droplet size distribution for water-in-crude oil emulsion measured by NMR (water phase: 3.5 wt.% solution of NaCl) prepared for 5 min (circles) and 15 min (triangles) at 2000 rpm (Kolotova et al., 2017).

FIGURE 8.13 Thermograms of crystallization for the crude oil emulsions prepared with 3.5% solution of NaCl at 2000 rpm for: (A) 5 min, (B) 15 min.

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Separators are designed to produce oil and emulsion containing between 5% and 10% water. Such produced oil and emulsion could be treated easily in the oil dehydration facility. Yong et al. (2016) reported the use of natural sand for separating oil from oil
water sludges. They showed that prewetted sand exhibits superoleophobicity and ultralow oiladhesion in water medium based on its strong water-absorbing ability. A prewetted sand layer is successfully applied for oil
water separation and shows extremely high separation efficiency and separation capacity. This method for separating oil and water is simple, almost free of cost, green, and very efficient (Picture 8.1). In the past, “water-removing” superhydrophilic and superoleophobic materials have been developed to address the problems described above, and they have proved extremely effective in practical applications (Cheng et al., 2013). However, it is harder to produce a superoleophobic material (with an oil contact angle (OCA) greater than 150 degrees) than to produce a superhydrophobic material because the surface tensions of oils are lower than the surface tension of water. A surface that is superoleophobic in air will generally need to have a very rough micro/nanoscale hierarchical structure or a re-entrant surface curvature, and will need to undergo rigorous chemical modifications to give it a low surface free energy. An alternative method of preparing a superoleophobic interface in an aqueous medium, inspired by fish scales, was recently described by Liu et al. (2009). The wetting/antiwetting behavior of liquid droplets on a solid surface is not an apparent or simple contact between two phases, but among three phases. Inspired by the antiwetting behavior of oil droplets on fish scales in water, a superoleophobic and low-adhesive interface is created on a solid substrate with micro/nanohierarchical structures, using oil/water/solid three-phase systems. PICTURE 8.1 Sands for separation of oil and water (Yong et al., 2016).

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They found that water trapped in the rough-surface microstructures of fish scales forms a layer that repels oil. The trapped water layer makes the surfaces of the scales underwater superoleophobic, giving the fish an oil-repellent skin. Following this strategy, many mesh and porous materials that are underwater superoleophobic have been fabricated, and these materials have been successfully applied in oil
water separation. Carp (inset of Fig. 8.11A) has tenacious survival capability even in an adverse natural environment. Its skin is fully covered by fan-shaped scales which are composed of hydrophilic calcium phosphate skeleton and protein and a thin layer of mucus. The scale surface is not smooth but shows a kind of a micro-/nanoscale hierarchical structure. There are many micropapillae with the size of several hundred micrometers fanning out on the scale surface (Fig. 8.14A and B). The size of the micropapillae decreases from the central area to the edge of the scales. The top and the side wall of every micropapilla are further decorated with abundant nanoscale “small pimples” (Fig. 8.14C). Underwater superoleophobicity is presented by fish scales. In water, when an oil (1,2-dichloroethane) droplet is put on a scale surface, the oil droplet will keep as a ball shape with an oil contact angle (OCA) of 151.5 6 2 degrees (inset of Fig. 8.14C). Fig. 8.14D
F shows the result of dripping an oil droplet onto the skin of a horizontal carp. The oil droplet can easily roll away without leaving any stain on the fish skin. Such excellent antioil ability allows fish to maintain its very high swimming speed in turbid or even oilpolluted waters. If some scales peeled from a fresh fish are exposed to the air, they will curl after being dried, demonstrating that fresh fish scales are high in water content. It is the high water content (16.4%
17.8%) as well as the inherent hydrophilicity that results in underwater superoleophobicity of fish scales and further endows fish skin with an oilrepellent function.

FIGURE 8.14 Underwater superoleophobicity and antioil ability of the carp skin. (A
C) Scanning electron microscopy (SEM) images of the fish scale surface. Inset of (A): Photograph of a carp. Inset of (C): Shape of an oil (1,2-dichloroethane) droplet on a fish scale surface in a water medium. (D
F) Snapshots of an oil droplet dripping onto the skin of a horizontal carp (Yong et al., 2018).

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Cheng et al. (2013) developed a new approach based on self-assembly of mixed thiols (containing both HS(CH2)9CH3 and HS(CH2)11OH) on nanostructured copper substrates for the fabrication of surfaces with controlled underwater oil wettability. By simply changing the concentration of HS(CH2)11OH in the solution, surfaces with controlled oil wettability from the underwater superoleophilicity to superoleophobicity was achieved. The tunable effect can be due to the synergistic effect of the surface chemistry variation and the nanostructures on the surfaces. Noticeably, the amplified effect of the nanostructures can provide better control of the underwater oil wettability between the two extremes: superoleophilicity and superoleophobicity. Moreover, we also extended the strategy to the copper mesh substrates and realized the selective oil/water separation on the as-prepared copper mesh films. Similarly, Liu et al. (2009) used coated microscale porous stainless steel mesh with a nanostructured hydrogel to give a novel underwater superoleophobic rough mesh. This hydrogel-coated mesh efficiently removed water from water
oil mixtures and did not become fouled with oil. Zhang et al. (2013a,b) proposed a novel all-inorganic Cu(OH)2 nanowire-haired membrane with superhydrophilicity and underwater ultralow adhesive superoleophobicity. It is fabricated with a facile surface oxidation of copper mesh that allows effective separation of both immiscible oil/water mixtures and oil-in-water emulsions solely driven by gravity, with extremely high separation efficiency. fabricated a Cu(OH)2 copper mesh with a nanowire-hair microstructure, and this material was superhydrophilic and underwater superoleophobic. This rough mesh had a high separation capacity for both water-rich immiscible mixtures and dispersed oil
water mixtures. The all-inorganic membrane exhibits superior solvent and alkaline resistance and antifouling property compared to organic-based membranes. The mechanism is shown in Fig. 8.15. Gao et al. (2014) described an underwater superoleophobic porous nitrocellulose membrane with both microscale and nanoscale pores. Large-area dual-scaled porous nitrocellulose (p-NC) membranes were fabricated with a facile, inexpensive, and scalable perforating approach. These p-NC membranes show stable superhydrophilicity in air and underwater superoleophobicity. The p-NC membranes with intrinsic nanopores and array of microscale perforated pores could selectively and efficiently separate water from various oil/water mixtures with high efficiency ( . 99%) rapidly. FIGURE 8.15 Schematic of the mechanism involved in nanowire copper mesh.

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The membrane had a high oil
water separation efficiency, even in a corrosive liquid environment. Although this route has proven to be effective in the laboratory, some difficulties and challenges still remain for using them for practical applications. Problems that have not been adequately addressed are the cost of the materials, the equipment required, and the preparation processes required—all of which prevent large-scale applications. Another issue is that the most widely used materials are metal meshes and porous polymers that have rough microscale
nanoscale hierarchical structures, which are generally formed using chemical corrosion or other chemical methods, meaning that solving one environmental problem (oil pollution) could cause another (disposing of the waste produced to create the superoleophobic material). It is therefore very important that we develop or find stable materials that are underwater superoleophobic and can be used to simply, cheaply, and efficiently separate large amounts of oil
water mixtures. Fish scales were the first materials that were discovered to show underwater superoleophobicity (Liu et al., 2009). The characteristics of fish scales suggest that surfaces that are superhydrophilic in air are generally superoleophobic in water. Deserts, which are largely uninhabitable, cover a significant area of the earth’s surface. In addition, deserts are encroaching on cities where we live, and often cause air pollution when sandstorms occur. The main component of sand is silicon dioxide. Sand also contains several metal elements. Silicon dioxide and metals usually have a high surface free energy. In addition, it is known that the sand surface contains a large number of hydroxyl groups. Its chemical composition with high surface free energy and hydroxyl groups endows the sand surface with intrinsic hydrophilicity. Dry sand has a tremendous ability to absorb rain. The excellent hydrophilic property of sand suggests that sand may be superoleophobic underwater and could possibly be used to separate oil and water. Yong et al. (2013) reported that sand shows quasi-underwater superoleophobicity and ultralow oil-adhesion for various oils upon immersion of sand in water. Those properties arise from the excellent water absorption capacity of sand. By making use of the underwater superoleophobic properties, a prewetted sand layer was successfully applied in oil
water separation. The good separation effect demonstrates that this strategy for oil
water separation is feasible for use in “real-life” applications. The sand used in their experiments was obtained from the Tengger Desert (Fig. 8.16A). Fig. 8.16C
E shows scanning electron microscopy (SEM) images of the sand. The sand particles have diameters of 130
270 μm. The surface of the sand particle is not smooth, but has a microscale rough texture (Fig. 8.16D). In addition, abundant nanoscale particles and debris distribute randomly over the sand surface (Fig. 8.16E). The measured surface roughness is 49
75 nm. The sand layer forms a typical three-level roughness structure, that is, with macroscale, microscale, and nanoscale roughness. There are large empty spaces between the sand particles. A water droplet falling onto sand-covered ground quickly infiltrates the sand, that is, in less than 0.03 second (Fig. 8.16F). This amazing permeation velocity indicates that sand is superhydrophilic. Figs. 8.16B and 8.17A show droplets of heavy oil (1,2-dichloroethane) on a sand layer in water. Each oil droplet is like a small sphere, and the OCA is 148.5 6 2.5 degrees, very close to the superoleophobicity criterion. The adhesive force was as low as 5.5 μN. Only underwater oil droplets with volumes of 8 μL and more could be placed onto the sand surface through gravity. The ultralow oil-adhesion can also be verified by the dynamic

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FIGURE 8.16 Microstructure and water absorbing ability of the sand layer. (A) Photograph of the Tengger Desert. (B) Photograph of oil droplets on the sand surface in water. (C
E) SEM images of sand particles. (F) Time series of a water droplet falling onto a sand layer in air.

properties of the oil droplet, as shown in Fig. 8.17D. The oil droplet easily rolled off the sand surface when the surface was tilted by 5.9 degrees, meaning that the oil sliding angle (OSA) was 5.9 degrees. In addition, the sand shows oil-repellent behavior not only for heavy oils but also light oils. Fig. 8.18B and E shows the static shape and dynamic sliding behavior of a light oil droplet (petroleum ether) on the sand surface in water medium. The prewetted sand surface shows underwater quasi-superoleophobic or superoleophobic

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FIGURE 8.17 Quasi-underwater superhydrophobicity and ultralow oil-adhesion of a sand layer in water. (A) Heavy oil (1,2-dichloroethane) droplet and (B) light oil (petroleum ether) droplet on a layer of sand in water medium. (C) An underwater heavy oil droplet making contact with and losing contact with a sand layer. (D) Heavy oil droplet and (E) light oil droplet rolling on a tilted sand layer in water.

properties and ultralow oil-adhesion for a wide range of oils (including decane, dodecane, hexadecane, sesame oil, crude oil, diesel, paraffin liquid, and chloroform), as shown in Fig. 8.18. The OCA values for these oils range from 146 to 151.5 degrees, and the OSAs are all less than 10 degrees. The underwater superoleophobicity and ultralow oil-adhesion indicate that an underwater oil droplet on the sand surface is in an underwater Cassie contact state. Sand is an intrinsically superhydrophilic material that will be fully wetted (that is, the spaces between the sand particles will be filled with water) when immersed in water. A water cushion will form below an oil droplet placed on a sand layer in water. This cushion prevents the oil droplet from effectively making contact with the sand. The oil droplet only sits on top of the rough microstructure, forming an oil
water
sand three-phase system.

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FIGURE 8.18 Oil contact angles and oil sliding angles for droplet of different oils on the sand layer in water medium. It shows that the sand layer is underwater quasi-superoleophobic or actually superoleophobic and has ultralow oil-adhesion.

Water molecules (which are polar) strongly repel oil molecules (which are nonpolar), so the trapped water cushion is an ideal oil-repellent medium, endowing the sand surface with underwater superoleophobicity. The sand can be used in oil
water separation for their (quasi)underwater superoleophobicity. As shown in Fig. 8.19A, a layer of sand about 1 cm deep was fixed between two plastic tubes to act as a separating membrane. A piece of cloth was placed below the sand to prevent the sand from being lost. Before the separation process, the sand layer was prewetted with water. It was simply achieved by pouring a small amount of water into the upper tube (Fig. 8.19B). A mixture of water and oil (petroleum ether) was then poured into the upper tube (Fig. 8.19C). The water was dyed with methylene blue to obtain a blue color; the oil was dyed with Oil Red O and showed a red color. It was clear that only water could permeate the sand layer quickly and that the oil was retained in the upper tube (Fig. 8.19D). The result demonstrates that a prewetted sand layer can be functionalized to serve as an oil
water separation membrane. The water fluxes of the prewetted sand layer with different thickness were calculated by measuring the time for a petroleum ether/water mixture of a certain volume (the height of the water column was 15 cm; the height of the oil column was 5 cm) to permeate through, as shown in Fig. 8.20A. It can be clearly seen that the water flux decreases quickly with increasing sand thickness due to an increase of effective penetration distance. The longer penetration distance results in larger viscidity resistance. When the thickness of the sand layer is 0.5 cm, the water flux can reach up to 9648 L/m2h. To obtain a maximum separation speed, the used sand layer should be as thin as possible to meet the requirements for effective oil
water separation. The thickness also has an important influence on the intrusion pressure of oil, which can be accurately assessed by the maximum supporting height of the oil column. As shown in Fig. 8.5B, the maximum oil (petroleum ether) column height increases with the increase of the thickness of the sand layer.

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FIGURE 8.19 Oil
water separation study using a prewetted sand layer. (A) Experimental setup. (B) Prewetting the sand layer with a small amount of water. (C, D) A mixture of water (blue) and petroleum ether (red) was poured into the upper tube. (E
H) Restarting the oil
water separation process by adding new water to the upper tube.

(A)

(B)

Oil column height (cm)

Water flux (L m-2h-1)

10000

8000

6000

4000

2000 0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Thickness of sand layer (cm)

65 60 55 50 45 40 35 0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Thickness of sand layer (cm)

FIGURE 8.20 Influence of the thickness of the prewetted sand layer on (A) the water flux and (B) the maximum supporting height of the oil column.

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The water flux and the maximum supporting height of the oil column have a contrary change trend, similar to others’ observation (Wen et al., 2013). Wen et al. (2013) unveiled the same mechanism, using another natural material, zeolite. As we have seen in previous chapters, Zeolite films have attracted intense research interest due to their unique pore character, excellent chemical, thermal and mechanical stability, and others. Wen et al. (2013) first demonstrate zeolite-coated mesh films for gravity-driven oil
water separation. High separation efficiency of various oils was achieved based on the excellent superhydrophilicity and underwater superoleophobicity of the zeolite surface. Flux and intrusion pressure are tunable by simply changing the pore size, dependent on the crystallization time of the zeolite crystals, of the zeolite meshes. More importantly, such films are corrosion-resistant in the presence of corrosive media, which gives them promise as candidates in practical applications of oil
water separation (Fig. 8.21). Yong et al. (2013) quantified their technique to oil that is not too heavy for natural separation since the heavy oil settles below the water, creating a layer of oil between the water and the sand layer (Fig. 8.22). A U-shaped sand ridge can be used to address

FIGURE 8.21 Schematic of the mechanism involved in oil
water separation with zeolite.

FIGURE 8.22 Schematic illustration of separating a mixture of heavy oils and water based on a prewetted U-shaped sand ridge.

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the separation of this type of mixtures, as shown in Fig. 8.22. The sand is first piled up as a U-shaped ridge. Then, the sand ridge is prewetted with water. Because of the superhydrophilicity and capillary action, even the top part of the sand ridge can be wetted. Vorobyev and Guo (2015) used a new technique for characterizing materials in nanoscale. They report a maskless laser nano-lithographic technique to construct high-quality two-dimensional periodic nanodomes on glass. The glass sample is first coated with a thin copper film and then irradiated by femtosecond laser pulses. We show that the period and size of the nanodomes can be controlled using a multifluence process. They later employed a single-fluence technique, for the first time, for high-quality nanopatterning on glass. The nanopatterning formation mechanism is studied by dynamics experiments and numerical simulations. Recent work of Liu et al. (2022) reveals why desert sands are uniquely capable of separating oil and water, as evidenced by Yong et al. (2022). In the paper by Liu et al. (2022), the size and shape characteristics of desert sand particles were quantitatively investigated via X-CT scanning and reconstruction based on SH functions. Three samples were scanned and 2218 particles were analyzed to make sure the obtained data had statistical meaning. The following conclusions were reported: 1. The size characteristics of the desert sand particles were quantitatively evaluated via the length (L), width (W), thickness (T), and the volume equivalent spherical diameter (VESD). The average value of the VESD for the desert sand particle is 118.2 μm, which is much smaller than that of commonly used fine aggregate, and more than 90% particles are smaller than 130 μm. 2. The overall shape of the desert sand particles was assessed based on two aspect ratios: elongation (EI) and flatness (FI) and the desert sand particles were classified into four categories: spheroid-shaped, oblate-shaped, prolate-shaped, and blade-shaped, with tained results had statistical meaning. It is well-known that wood is one of the superabsorbent materials. A 1.005 g dry wooden block (44 3 37 3 5 mm3) will become 2.021 g if it fully absorbs water. The absorbed water (1.016 g) has almost the same weight as the dry wooden block. The water content of the wetted balsa wood in water can be estimated at about 50.3%; this value is much greater than that of fresh fish scales. The high water content of wetted balsa wood reveals that it may be underwater superoleophobic and could possibly be used to separate water/ oil mixtures. There are abundant micropipes in the tree trunk, allowing water to flow from the base to the top of the tree. When the tree was sawn into sheets, those micropipes would break, resulting in many microgrooves on the surface of the wood sheets. Fig. 8.23A
C shows the SEM images of the surface of a wood sheet. The surface is fully covered by ordered microgrooves. The grooves are about several tens microns in width. The wall of the grooves is not smooth. It was found that a very large number of protrusions with a size of several hundred nanometers are randomly distributed on the wall of the microgrooves (Fig. 8.23C). When a water droplet was dripped onto the wood surface, the droplet would spread out quickly and be absorbed by the wood sheet. The water contact angle was close to zero, revealing inherent superhydrophilicity of the wood surface. It has been demonstrated that most in-air superhydrophilic materials will show

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In water

(A)

(B)

(C)

Oil

(D) Water

(E)

t=0.00s In air

t=0.32s

t=1.28s

t=4.16s

t=9.92s

t=0.00s In water

t=0.24s

t=0.48s

t=0.72s

t=0.96s

Oil

FIGURE 8.23 Microstructure and underwater superoleophobicity of the wood sheet surface. (A
C) SEM images of the wood sheet surface. Inset of (A): shape of an underwater oil droplet (1,2-dichloroethane) on the wood surface. Inset of (C): corresponding high-magnification image of the wood texture. (D) Snapshots of a water droplet spreading on a wood sheet in air. (E) Snapshots of an oil droplet rolling off a wood sheet tilted 6.5 degrees in water.

superoleophobicity in water. When the wood sheet was immersed in water and some oil droplets (1,2-dichloroethane) were placed on its surface, the oil droplets maintained a spherical shape rather than spreading out (inset of Fig. 8.23A). The OCA was as high as 162.5 6 2 degrees, so the wood sheet exhibited underwater superoleophobicity. If the surface was tilted more than 6.5 degrees, the underwater oil droplet would roll off the wood surface easily. Such a low OSA value (6.5 degrees) indicated a very small adhesive force between the underwater wood surface and the oil droplet. The adhesive force was measured to be only 3.7 μN. In addition to 1,2-dichloroethane, the wood sheet also showed underwater superoleophobicity and very low oil adhesion to a wide range of other oils, regardless of whether they were heavy oils or light oils. Fig. 8.24 depicts the static shapes and dynamic rolling snapshots of some common oil droplets on the wood sheet in water. The measured OCAs and OSAs are 151.5 and 6 degrees for hexadecane, 161.5 and 8.5 degrees for dodecane, 152 and 8 degrees for decane, 153.5 and 7 degrees for petroleum ether, 150.5 and 4 degrees for paraffin liquid, 151.5 and 5 degrees for sesame oil, 153.5 and 5.5 degrees for kerosene, and 154.5 and 3.5 degrees for crude oil, respectively. Surface wettability is mainly governed by the surface chemistry and microstructures. As soon as the wood sheet was immersed in water, the wood would absorb water quickly, and water would fully wet the surface microstructures. A thin water layer was trapped in the microstructures. When an oil

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FIGURE 8.24

Static shape and the dynamic rolling behavior of different oil droplets on a wood sheet in a water medium.

droplet was put on the wood sheet immersed in water, the trapped water like a water cushion would prevent the oil droplet from contacting with the wood substrate effectively because the polar water molecule generally repels the nonpolar oil molecules. In fact, the oil droplet could only touch the tips of the rough microstructures, which was at the underwater Cassie wetting state. The contact area between the wood substrate and the oil droplet is so small that the wood sheet is endowed with underwater superoleophobicity and low oil adhesion. Yong et al. (2018) discovered that wood sheet shows underwater superoleophobicity and low oil adhesion in water, resulting from its strong capacity of absorbing water. A through-microhole array was created on the wood sheet surface by a simple mechanical drilling process. The prewetted porous sheet had great ability to separate the mixtures of water and oil with high separation efficiency. Wood is a low-cost, green, and natural ecofriendly material; therefore, can lead to a simple, low-cost, efficient, and green route of large-scale oil/water separation. It is well-known that wood is one of the superabsorbent materials. A 1.005 g dry wooden block (44 3 37 3 5 mm3) will become 2.021 g if it fully absorbs water. The absorbed water (1.016 g) has almost the same weight as the dry wooden block. The water content of the wetted balsa wood in water can be estimated at about 50.3%; this value is much greater than that of fresh fish scales. The high water content of wetted balsa wood reveals that it may be underwater superoleophobic and could possibly be used to separate water/oil mixtures. There are abundant micropipes in the

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tree trunk, allowing water to flow from the base to the top of the tree. When the tree was sawn into sheets, those micropipes would break, resulting in many microgrooves on the surface of the wood sheets. A through-microhole array with a period of 1 mm was easily formed on a wood sheet (thickness of 1 mm) by a mechanical drilling process, as shown in Fig. 8.25A and B. These

(A)

(B)

–Water (C)

0.00s

0.01s

0.02s

(D)

0.00s

0.05s

0.07s

(E)

OCA = 155.5r2°

(F)

OSA = 7r2°

0.10s

0.13s

0.16s

(G)

Water

Oil Wood

FIGURE 8.25 Microstructures and wettability of the MHWS. (A) Optical microscopy image of the MHWS in water. (B) SEM image of the through-microhole on the wood sheet. (C, D) Process of water droplets penetrating through the MHWS (in air) with increasing water volume continuously. (E) Static shape and (F) rolling snapshot of an underwater oil droplet on the MHWS surface. (G) Schematic diagram of the wetting state of an underwater oil droplet on the MHWS (Yong et al., 2018).

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microholes with the diameter of B340 μm go right through the sheet. The diameter of the through microholes is larger than that of the used drill bit (300 μm) because of the drillingprocess-induced extrusion and stretch effects. The rest area maintains its inherent micro-/ nanoscale hierarchical structures except for the microholes (Fig. 8.25B). When the microholes-through wood sheet (MHWS) was immersed in water, the wood sheet would absorb a large amount of water. Although the diameter of the microholes would decrease slightly as well, the drill-induced microholes were still open after some time. This could be observed by an optical microscope. As shown in Fig. 8.25A, the microhole region showed white color because the backlight generated from the optical microscope could pass through the microholes. In contrast, the backlight was blocked by the rest region and such a region looked very dark. If a water droplet was dripped onto the MHWS, the water would spread out quickly within only 0.02 second because of the strong superhydrophilicity of wood (Fig. 8.4C). With more and more water droplets being dripped onto the resultant surface, the water penetrated through the sheet and dripped down because there are a lot of perforated micropores distributing on the wood sheet (Fig. 8.25C and D). The MHWS still had superoleophobicity and low oil adhesion with an OCA of 155.5 6 2 degrees (Fig. 8.25E) and an OSA of 7 6 2 degrees (Fig. 8.25F) in a water medium. In this case, water was trapped in not only the surface microstructures but also the through microholes. The underwater oil droplet on the MHWS surface was also at the underwater Cassie state, as shown in Fig. 8.25G. As another important performance of the separation device, the intrusion pressure of oil was simply calculated by measuring the maximum supporting height of the oil column. It can be seen from Fig. 8.26 that the intrusion pressure changes little as the period increases from 1 to 3.5 mm. The intrusion pressure is almost a constant value in the range of experimental errors, regardless of whether the microholes are close or not. In fact, the drilled microholes worked independently and had no interference with each other, so the intrusion pressure did not depend on the density as well as the period of the microhole array. Such a result is very different from the rough meshes and fabrics. The influence

FIGURE 8.26 Variation of flux and intrusion pressure with the period of the MHWS which was drilled with a thin drill bit 300 μm in diameter.

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of the pore size on the water flux, intrusion pressure, and separation efficiency was also investigated. For comparison, a bigger drill bit with a diameter of 500 μm was used to generate larger microscale through-holes on a wood sheet. The flux values for the latter case are much larger than that for the former case, whereas the intrusion pressure values for the latter case are much less than those for the former case. Such low intrusion pressure sometimes leads to a failed separation. Therefore, using the drill bit with a diameter of 300 μm to treat the wood sheet is optimal. In addition, we found that increasing the thickness of the wood sheet is bad for achieving oil/water separation. The through-microholes of the thicker wood sheet are more inclined to be blocked after immersing in water because of the expansion of the wood. In order to determine the role of temperature on effectiveness of oil
water separation, Cassie’s law is helpful. Cassie’s law, or the Cassie equation, describes the effective contact angle θc for a liquid on a chemically heterogeneous surface, that is, the surface of a composite material consisting of different chemistries, that is nonuniform throughout (Cassie, 1948). Contact angles are important as they quantify a surface’s wettability, the nature of solid
fluid intermolecular interactions (Handerson, 2000). Cassie’s law is reserved for when a liquid completely covers both smooth and rough heterogeneous surfaces (Milne and Amirfazli, 2012). More of a rule than a law, the formula found in literature for two materials is as follows: cos θc 5 σ1 cos θ1 1 σ2 cos θ2 where θ1 and θ2 are the contact angles for components 1 with fractional surface area σ1, and 2 with fractional surface area σ2 in the composite material respectively. If there exist more than two materials, then the equation is scaled to the general form of cos θc 5

N X

σk cos θk

(8.6)

k51

where N X

σk 5 1

k51

Cassie’s law takes on special meaning when the heterogeneous surface is a porous medium. In this case, σ1 represents the solid surface area and σ2 air gaps, such that the surface is no longer completely wet. Because air creates a contact angle of 180 degrees, the new equation becomes the Cassie
Baxter equation (Cassie and Baxter, 1944): cos θcb 5 σ1 cos θ1 2 σ2

(8.7)

West (2018) used a variation of the Cassie
Baxter equation to represent two-fluid systems:





cos θesp 5 χester cos θester 1 χccarboxy cos θcarboxy With χester 1 χcarboxy 5 1

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In these experiments, the contact angles of the unmodified ester containing SAMs (θester 5 58 degrees) and of the totally hydrolyzed surface (χcarboxy 5 15 degrees) need to be known (Fig. 8.27). The results were compared with those for single-shot experiments in which one individual SAM was allowed to react in the presence of 0.1M NaOH for a given reaction time. The agreement between the two experiments was excellent and allowed to validate the gradient tracking of ester hydrolysis method. From these experiments, the activation energy for the studied reaction could be determined from a single SAM coated on a 200nm-thick gold films deposited on glass (with a thin Ti primer layer). In conclusion, he demonstrated that sand shows (quasi)underwater superoleophobicity with ultralow oil-adhesion due to its powerful water-absorbing ability. An oil
water
sand three-phase system formed when an oil droplet was placed on a sand

(A) High temperature Rapid hydrolysis COO- COOLow contact angle

COO-

Low temperature Slow hydrolysis High contact angle

COO-

Temperature gradient

(B)

50 45

Texp (°)

50 40 40 35 30

30

Temperature (°C)

60

20

25 0

5

10

15

20

posion from the beginning of the temperature gradient (mm) FIGURE 8.27 (A) Schematic representation of a temperature gradient applied along a self-assembled monolayer terminated with ester moieties (blue disks [gray in print versions]) and of the differential surface composition resulting from the NaOH-catalyzed hydrolysis after a given reaction time. (B) Representation of the temperature decrease ( [gray in print versions]) and of the contact angle increase ( ) along the surface after 10-min NaOHcatalyzed hydrolysis.

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layer immersed in water, and the oil droplet was in an underwater Cassie wetting state. Taking advantage of the underwater superoleophobicity, a prewetted sand layer was successfully used for oil
water separation. Our system showed an extremely high separation efficiency and separation capacity. Suitable sand for use in such separations can be directly obtained from desert environments and does not need to be treated before use. This simple, almost free, green, large-scale, and highly efficient route of separating oil and water offers a new perspective on practically solving pollution problems caused by oily industrial wastewater and oil spills.

8.4 Sand jets and drains In horizontal separators, one worry is the accumulation of sand and solids at the bottom of the vessel. If allowed to build up, these solids will upset the separator operations by taking up vessel volume. Generally, the solids settle to the bottom and become well packed. To remove the solids, sand drains are opened in a controlled manner, and then highpressure fluid, usually produced water, is pumped through the jets to agitate the solids and flush them down the drains. The sand jets are normally designed with a 20-ft/s (6-m/s) jet tip velocity and aimed in such a manner to give good coverage of the vessel bottom. To prevent the settled sand from clogging the sand drains, sand pans or sand troughs are used to cover the outlets. These are inverted troughs with slotted side openings (Fig. 8.28).

FIGURE 8.28 Schematic of a horizontal separator fitted with sand jets and inverted trough (Stewart and Arnold, 2008).

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To ensure proper solids removal without upsetting the separation process, an integrated system, consisting of a drain and its associated jets, should be installed at intervals not exceeding 5 ft (1.5 m). Field experience indicates it is not possible to mix and fluff the bottom of a long, horizontal vessel with a single sand jet header. A rigorous experimental and mathematic model for describing jet flow within a gas
solid
liquid system was developed by Fan et al. (2001). In a dilute phase condition, the evaporative liquid jet was introduced into a dilute pneumatic convey system. The general structure of evaporative liquid jets can be sectioned into a central core of dense vapor droplets and a surrounding region of dispersed vapor droplets as illustrated in Fig. 8.29. Through the use of a temperature monitoring system, the boundary between these two regions are determined by a characteristic sudden temperature increase across the boundaries as demonstrated in Fig. 8.30 and reconfirmed through the visualization shown. This chart not only indicates the primary location of evaporation but also implies the boundaries importance in the rate of evaporation. Of further interest, the temperature along the dense core region is constant and may imply the gas temperature being near the same temperature as the liquid droplets. This characteristic temperature drop is not unique to particle-free flows, but also remains true for solid-laden flows. Upon adding a relatively small solids loading of FCC particles to the air stream (1.6% by volume), a significant decrease in jetting boundaries is shown in Fig. 8.31 and demonstrates the severe influence that solid particles may have on the effectiveness of liquid jets. The high heat capacity with respect to gas and liquid phases provides an exceptionally large heat sink that promotes evaporation and adds another dimension to the already complicated, dynamic problem as liquid
solid interactions must be considered. Based on experimental observations, a similarity model was developed as a first-step approach toward describing jet evaporation and characteristic regions in gas
solid suspension flows as schematically shown in Fig. 8.32. All radial properties of the phases are assumed to follow similarity laws in the jetting region and a representation of the control

FIGURE 8.29

Evaporative liquid nitrogen jet in air.

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FIGURE 8.30 Determination of jet boundary via thermocouples.

FIGURE 8.31 Effects of solids concentration on spray jet evaporation.

volumes used is shown. Within the dispersed region, the fluidizing gas and evaporated vapor are assumed perfectly mixed and suspended within the gas flow, while the temperature of the gas in the core is considered to be very close to the droplet temperatures. Furthermore, evaporation is only allowed to occur within the core. With these assumptions, conservation of mass, momentum, and energy are applied with approximated closure equations.

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FIGURE 8.32

8. Fundamental considerations of oil and gas separation

Schematic diagram of axisymmetric evaporating jet and setup of control volume for modeling.

The following equations provide closure to the conservation balances for the radial distribution of particle (αP) and droplet (αd) volume fractions, radial distribution of jet velocity, and outer jet boundary.  3   αp r 5 Skouby; 1998 ; (8.9) αp0 Rb  1:5 αd r 512 for water ðAbramovich; 1963Þ; (8.10) αdc Re  U 2 Ua π r ðSubramanian & Venktram; 1985Þ (8.11) 5 cos Uc 2 Ua 2 Rb !   dRb 1 2 Ua =Uc    for U a =Uc , 1 ðAbramovich; 1963Þ: _ d Þ0:11 1 1 ρa =ρc 5 β ðm dx 1 1 ρa =ρc Ua =Uc (8.12)

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However, this last equation does not account for the expanding evaporated droplets and requires some adjustment. By assuming the velocity distribution remains unchanged, the boundary is altered to account for the expansion. This assumption implies the broadening of the jetting boundaries as evaporation rates increase. Mass conservation equations may now be derived to account for particle entrainment (ṁ ep) and mass generation of droplet phase (ṁ d). _ ep Δx 5 m

ð4 3

_ d Δx 5 m

ð2 1

2πrαp ρp Udr 2

2πrαd ρd Udr 2

ð2 1

ð4 3

2πrαp ρp Udr; (8.13)

2πrαd ρd Udr:

whereas gas entrainment, ṁ eg, may be similarly expressed except with a phase generation term (ṁ dΔx) due to evaporation. _ eg Δx 5 m

ð4 3

2πrαg ρg Udr 2

ð2 1

_ d Δx: 2πrαg ρg Udr 2 m

(8.14)

Neglecting external body forces and pressure gradients, the overall momentum equation for a differential control volume becomes ð2 1

2πrρU ðU 2 Ua Þdr 5

ð4

2πrρU ðU 2 Ua Þdr:

(8.15)

3

As evaporation may occur through liquid
solid or gas
liquid contact and thermal radiation, assumptions of infinitely fast heat and mass transfer are made for simplicity. These assumptions are reasonable for solid particles with low Biot numbers or systems with perfect mixing with surrounding gas streams at low vapor concentration. In addition to these assumptions, only entrained energy can compensate for the latent heat of evaporation. Thus, the energy balance is of the form   _ ep C ðTa 2 Td ÞΔx 5 m _ d hfg Δx: _ eg Cpg 1 m (8.16) m

8.5 Vapor/liquid separation Vapor/liquid separation is usually accomplished in three stages. The first stage, primary separation, uses an inlet diverter to cause the largest droplets to impinge by momentum and then drop by gravity. The next stage, secondary separation, is gravity separation of smaller droplets as the vapor flows through the disengagement area. Gravity separation can be aided by utilizing distribution baffles that create an even velocity distribution in the fluid, thus allowing enhanced separation. The final stage is mist elimination, where the smallest droplets are coalesced on an impingement device, such as a mist pad or vane pack, followed by gravity settling of the larger formed droplets.

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8.5.1 Aerosols Aerosols are formed by three mechanisms: • Condensation. • Atomization. • Entrainment. The process is similar to what occurs in combustion chamber, as used in engineering applications, such as spray cooling and spray combustion (Luo et al., 2019). One such application, spray combustion can be divided into several subprocesses, such as fuel injection, atomization, droplet dispersion, evaporation, fuel-air mixing, and combustion, as illustrated in Fig. 8.33. Liquid fuel is firstly injected from the nozzle in the form of bulk liquid to the chamber and then is atomized into large numbers of fine droplets. The atomization process can further be divided into primary atomization and secondary atomization. The primary atomization is defined as the process from bulk liquid to filaments and droplets, and the secondary atomization is defined as the process from the filaments and droplets to much smaller droplets. In a separator, condensation takes place due to depressurization of the inlet crude oil. A variety of factors affect droplet size and how easily a stream of liquid atomizes after emerging from an orifice. During this transition droplet size is increased. Fig. 8.34 shows how droplet size changes as the fluid passes through phases of atomization then to entrainment. For the single-fluid nozzles, the droplets display monomodal size distributions, whatever the liquid outlet speed (Fig. 8.35). The measured droplet size distributions were described using different parameters (d10, d50, d90, d32, and d43). As illustrated in Fig. 8.36, we noticed that the effect of the liquid outlet speed on the droplet diameters (d32, d50, or d43) was almost similar whatever the considered size parameter. As in any case the size distribution was monomodal, we have thus chosen to discuss the influence of physicochemical and process parameters by only displaying the impact on the median diameter (d50) of the sprayed droplets.

FIGURE 8.33

A schematic of spray combustion process (From website 5).

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FIGURE 8.34 Particle size for various phases of vapor
liquid transition. Source: Modified from Mokhatab and Poe (2016).

60

Weight %

50 Condensation

40 30

Atomization

20

Entrainment

10 0 .01

.1

1 100 10 Particle Size (μm)

1000 10000

FIGURE 8.35 Droplet size distributions after atomization of pure water using a two-fluid pneumatic nozzle (0.41 mm inside diameter) for two different liquid flow rates and two different atomizing air pressures (Mandato et al., 2012).

FIGURE 8.36 Droplet size distributions after atomization of pure water using single-fluid nozzles of 0.66 mm inside diameter at outlet liquid speed of 26.6 and 20.9 m/s, and 0.28 mm inside diameter at outlet liquid speed of 15.4 m/s (Mandato et al., 2012).

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Whatever the liquid surface tension, we observe increases in the droplet diameter with liquid viscosity. For instance for a liquid at 62.5 mN/m surface tension, the droplet diameter is multiplied by 5 when the liquid viscosity increases from 1 to 72 mPa/s. We thus observed that the ability of the liquid to resist the dynamic forces of atomization is increased with increasing viscosity and/or surface tension. In the case of single-fluid nozzles, an increase in liquid viscosity and/or surface tension has been found to hinder the liquid disintegration and lead to an increase in the amount of energy required for the atomization and also an increase in the droplet diameter (Fig. 8.37). Fig. 8.38 shows the role of droplet diameter on liquid outlet speed.

FIGURE 8.37 Influence of liquid viscosity on droplet diameter (d50) after atomization of liquids of different surface tensions (42 mN/m [ ], 49 mN/m [ ], and 62.5 mN/m [ ]) using a single-fluid nozzle (0.66 mm inside diameter) at liquid outlet speed of 26.6 m/s.

FIGURE 8.38 Influence of liquid outlet speed on droplet diameters (d32 [ ], d50 [ ], and d43 [ ]) after atomization of pure water using two different single-fluid nozzles, at 0.28 mm (white symbols) or at 0.66 mm (blacks symbols) inside diameters. Pipelines

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The particle size depends on several factors, such as: • • • • •

Surface tension. Viscosity. Density. Acidity. Salinity.

Surface tension tends to stabilize a fluid, preventing its breakup into smaller droplets. Everything else being equal, fluids with higher surface tensions tend to have a larger average droplet size upon atomization. For a process that has numerous nanomaterials (of natural origin), another factor plays a role. That is, nanoparticles themselves alter the surface tension of the fluid. The effect of particle size on the interfacial tension of nanoparticles is unclear, and there exist conflicting conclusions about the value and sign of Tolman length. Wang et al. (2021) introduced a novel method of determining the interfacial tension (solid
liquid and solid
gas interfaces), temperature coefficient of interfacial tension, and Tolman lengths of nanomaterials by adsorption thermodynamics and kinetics. The Tolman length, δ (also known as Tolman’s delta) measures the extent by which the surface tension of a small liquid drop deviates from its planar value. It is conveniently defined in terms of an expansion in 1/R, with R 5 Re, the equimolar radius (defined below) of the liquid drop, of the pressure difference across the droplet’s surface:  2σ δ 12 1... (8.17) Δp 5 R R In this expression, Δp 5 pl 2 pv is the pressure difference between the (bulk) pressure of the liquid inside and the pressure of the vapor outside, and σ is the surface tension of the planar interface, that is, the interface with zero curvature. Wang (2019) determined the interfacial tension and its temperature coefficient of the solid
liquid interface of nano cadmium sulfide before adsorption were obtained, and further, the Tolman length was also obtained. The experimental results show that the particle size of nanoparticles has significant effects on the interfacial tension and its temperature coefficient. When the radius is larger than 10 nm, the interfacial tension and its temperature coefficient are almost constant with the decrease of the radius. When the radius is less than 10 nm, the interfacial tension decreases sharply and the temperature coefficient increases sharply with the decrease of the radius, and the temperature coefficient of the interfacial tension is negative. The Tolman length of the solid
liquid interface of nanoparticles is proved to be positive, and the particle size also has a significant effect on the Tolman length. The Tolman length decreases with the decrease of particle size. However, the effects of particle size on the Tolman length become significant only when the particle radius approach or reach the order of magnitudes of molecular (or atomic) radius. The effects of particle size on interfacial tension and Tolman length of nano cadmium sulfide obtained in this paper can provide significant references for the research and applications of interface thermodynamics of other nanomaterials. A fluid’s viscosity has a similar effect on droplet size as surface tension. Viscosity causes the fluid to resist agitation, tending to prevent its breakup and leading to a larger

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FIGURE 8.39 Viscosity, droplet size, and when atomization occurs.

average droplet size. Fig. 8.39 represents the relationship among viscosity, droplet size, and when atomization occurs. Similar to the properties of both surface tension and viscosity, higher density tends to result in a larger average droplet size. N H2O (l ) (ND). The maximum droplet number density is 108 m23 and corresponds to a dense cloud, the minimum droplet ND is 107 m23 and corresponds to a less dense cloud. The corresponding size distributions are shown in Fig. 8.40. A downcomer is required to transmit the liquid collected through the oil-gas interface so as not to disturb the oil-skimming action taking place. Vertical separators should be constructed such that the flow stream enters near the top and passes through a gas
liquid separating chamber even though they are not competitive alternatives unlike the horizontal separators. With the development of computational capacity, the level set method has been widely used to directly simulate the atomization process. In 2008 Gorokhovski and Herrmann outlined some severe numerical challenges that occur in interface-resolved modeling of primary

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597 FIGURE 8.40 Droplet size distribution for maximum droplet number density (black) and minimum droplet number density (gray) (Queisser et al., 2013).

atomization, and related numerical strategies to address them. The numerical issues are briefly summarized here as follows: length and time scales, interface topology changes, material property discontinuities, surface tension treatments, and inherent 3D configurations. The first category of numerical approaches concerns direct simulation of primary atomization. These approaches are based on integration of the Navier
Stokes equations, identifying the gas/liquid interface at each time step. Using this technique, liquid fragments break apart when the progressively stretched filament becomes smaller than the typical size of a numerical cell. Such approaches provide accurate local estimates of the gas/liquid mixture close to the injector, and may help in understanding the physics of primary atomization. However, when the Weber number is very large, the computational expense associated with the resolution of all length scales is very high. When the relative velocity between liquid and gas is more than, say, a hundred meters per second, droplets with diameters of a dozen or so microns may be produced, which is usually smaller than the resolution of the numerical grid. As a result, alongside direct numerical simulation, there is a need to develop phenomenological models, with more modest CPU requirements. The objective of conventional models is to represent statistically the essential features of the initial break-up. Although these models contain the mechanisms of the initial break-up of the liquid jet.

8.5.2 Direct numerical simulation of primary atomization The detailed physical mechanisms by which primary atomization occurs are as of this date not well understood. Thus, direct numerical simulation (DNS) of the primary

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atomization process can serve as a valuable tool to study the involved mechanisms in detail. In DNS, the goal is to resolve all time and length scales solving the governing equations directly. Since most primary atomization applications occur at low Mach numbers and the two fluids involved are immiscible, the flow is governed by the unsteady Navier
Stokes equations in the variable density, incompressible limit,    @ρu 1 u rρu 5 2 rp 1 r μ ru 1 rT u 1 ρg 1 Tσ @t



(8.18)

r u 5 0:

(8.19)





where u is the velocity, ρ the density, p the pressure, μ the dynamic viscosity, g the gravitational acceleration, and Tσ the surface tension force, which is nonzero only at the location of the phase interface xf. Although a DNS approach reduces epistemic uncertainty, the numerical requirements are extremely difficult to meet: • • • • •

Length and time scales vary over several orders of magnitude. The phase interface constitutes a discontinuity in material properties. Surface tension forces are singular forces active only at the phase interface. Turbulence and the turbulent primary atomization process are inherently three dimensional. Topology changes of the phase interface occur frequently.

8.5.3 Length and time scales In a single-phase turbulent flow, the smallest length scale that must be resolved is the Kolmogorov length scale η. Kolmogorov length scale is defined as η 5 (ν 3 /ε)1/4, where is the average rate of energy dissipation per unit mass, and ν is the kinematic viscosity of the fluid. Similarly, Kolmogorov time scale is defined as, τη 5 (ν/ε)1/2. Multiphase flows add an additional smallest length scale that requires resolution, the size of the smallest liquid structure ζ. Unfortunately, when topology change of the phase interface is involved, that length scale approaches zero, since the process of pinching involves at the very instance of breakup, a zero-sized connecting ligament. Such resolution requirements together with the breakdown of the continuum assumptions inherent in the Navier
Stokes equations make simulation of the details of the topology change process unfeasible in the context of DNS of the turbulent primary breakup process. Thus, modeling has to be introduced to address topology change. Using adequate topology change models, the smallest liquid structure ζ that then should be resolved is of the order of the smallest drop generated by the initial breakup. Depending on the interface tracking/capturing method used, this implies a grid resolution of about 2
5 grid cells per ζ.

8.5.4 Describing the motion of the phase interface To perform a DNS of the primary atomization process, the location and motion of the phase interface have to be described with high accuracy. Neglecting phase transition

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effects, the phase interface constitutes a material surface whose motion is described by   dxf 5 v xf dt

(8.20)

where the subscript f refers to a point on the phase interface. The straightforward way of describing the motion of the phase interface is to solve Eq. (8.3) for a collection of marker particles placed onto the phase interface. This is the so-called interface tracking approach. While flow solver grid nodes can be used as marker particles, thereby ensuring phase interface conforming flow solver grids, such an approach would require almost constant regridding or rezoning (84) due to the complex flow field at the phase interface during primary atomization. Instead, in the surface marker method, the marker points are connected to form a separate surface grid that is advected according to Eq. (8.3) in a Lagrangian way inside a fixed flow solver grid. An alternative to interface tracking methods is interface capturing methods. Here, the phase interface is imbedded into a fixed grid via the use of an additional scalar. Two principle methods have emerged in this class: the volume of fluid method and the level set method. In the former method, a marker function ψ is defined as the liquid volume fraction in each computational grid cell: ð   1 H x 2 xf dx (8.21) ψ5 V V with H the Heaviside function, resulting in a simple advection equation describing the motion of the phase interface, @ψ 1 v rψ 5 0: @t



(8.22)

One of the major advantages of the volume of fluid method making it a popular interface tracking method is that it can be constructed to be inherently liquid volume conserving. However, due to the discontinuous nature of ψ at the phase interface, see Eq. (8.4), special geometric algorithms have to be employed to solve Eq. (8.5) to avoid unacceptable numerical diffusion of ψ. In level set methods, a scalar ϕ is defined to be equal to some constant value ϕ0 at the location of the phase interface, and ϕ . ϕ0 in fluid 1 and ϕ , ϕ0 in fluid 2. From this definition and Eq. (8.3) the level set equation follows: @φ 1 v rφ 5 0: @t



(8.23)

Since the above definition of the level set scalar defines ϕ only at the location of the phase interface, there is significant latitude in defining ϕ away from it. For numerical reasons, one would like ϕ to be a smooth function, thus one of the most popular definitions is that of a signed distance function, that is, |rϕ| 5 1. The major drawback of the level set method is that it does not inherently preserve liquid volume. Since volume errors are proportional in size to the employed grid resolution, grid refinement strategies, like structured adaptive mesh refinement or the refined level set grid method (RLSG) can be employed to limit their impact. An alternative to grid

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refinement is to augment and correct the level set scalar by an additional numerical scheme, for example, the coupled level-set volume-of-fluid (CLSVOF) or mass conserving level set (MCLS) methods coupling level set and volume of fluid or the particle level set method, coupling marker particles and level sets. Defining ϕ as the signed distance, is, as indicated above, not a requirement. Instead, in the so-called conservative level set method (64), ϕ0 5 0.5 and ϕ away from the interface is defined to be a smeared out version of the liquid volume fraction ψ, that is,   1 d tanh 11 ; (8.24) φ5 2 2A where d is the minimum distance to the phase interface. Solving Eq. (8.23) in conservative form in conjunction with reinitializing ϕ according to Eq. (8.24) does show good volume conservation properties even in complex interface geometries.

8.6 Ideal gas law Vapor
liquid separation forms the core of crude oil processing. Conventionally, such behavior is studied through assuming single-component system, then gradually adding multicomponent systems. The original ideal gas law, which was used by even Einstein to construct Bose
Einstein theory, starts with Charles law and Boyle’s law. Charles law simply states the linear relationship between volume and temperature. It emerges from the simple observation that volume expands when gas is heated. Mathematically, it states as follows (Fig. 8.41): V~T Charles law, on the other hand, emerges from the observation that pressure reduces the volume of a given gas, with other parameters remaining the same. Mathematically, it is expressed as follows: P ~ 1=V

(8.25)

This relationship is expressed schematically in Fig. 8.42. Avogadro’s law is an experimental gas law relating the volume of a gas to the amount of substance of gas present. The law is a specific case of the ideal gas law. A modern statement is as follows: FIGURE 8.41

Depiction of Charles law.

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FIGURE 8.42

601

Depiction of Boyle’s law.

Avogadro’s law states, “equal volumes of all gases, at the same temperature and pressure, have the same number of molecules.” For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant. The gas particles are equally sized and do not have intermolecular forces (attraction or repulsion) with other gas particles. The gas particles move randomly in agreement with Newton’s Laws of Motion. The gas particles have perfect elastic collisions with no energy loss. Amedeo Avogadro’s (1776
1856) principal contribution to chemistry was a paper in which he advanced two hypotheses: (1) that equal volumes of gas contain equal numbers of molecules and (2) that elementary gases such as hydrogen, nitrogen, and oxygen were composed of two atoms. Avogadro’s famous paper was an attempt to reconcile Dalton’s atomic hypothesis with Gay-Lussac’s results on combining volumes. He could see something that seems obvious to our eyes, even if Dalton and Gay-Lussac could not see it: Dalton’s atomic model and Gay-Lussac’s observations on combining volumes would be mutually consistent if there were a simple relationship between atoms and volumes. In particular, Dalton’s atomic model would provide an excellent explanation of Gay-Lussac’s observations if every one of Gay-Lussac’s volumes contained the same number of Dalton’s atoms. Avogadro made this reasonable hypothesis (the “volumes” hypothesis), which is now sometimes called Avogadro’s law. Dalton’s law is the statement that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual component gases. The partial pressure is the pressure that each gas would exert if it alone occupied the volume of the mixture at the same temperature. At the beginning of the 19th century, the English scientist John Dalton proposed an atomic theory that became the basis for the study of chemistry. His theory contained five main propositions: 1. 2. 3. 4. 5.

All matter is comprised of tiny, definite particles called atoms. Atoms are indivisible and indestructible. All atoms of a particular element share identical properties, including weight. Atoms of different elements contain different masses. Atoms of different elements combine in fixed whole-number ratios when forming compounds.

When the temperature of a sample of gas in a rigid container is increased, the pressure of the gas increases as well. The increase in kinetic energy results in the molecules of gas striking the walls of the container with more force, resulting in a greater pressure. The French chemist Joseph Gay-Lussac (1778
1850) discovered the relationship between the pressure of a gas and its absolute temperature. Gay-Lussac’s Law states that the pressure of a given

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mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constant. Gay-Lussac’s Law is very similar to Charles’s Law, with the only difference being the type of container. Whereas the container in a Charles’s Law experiment is flexible, it is rigid in a Gay-Lussac’s Law experiment. The mathematical expressions for GayLussac’s Law are likewise similar to those of Charles’ Law:

Avogadro law implies

P P1 P2 5 and T1 T2 T

(8.26)

V~n where n is the amount of matter, usually expressed in mole. A graph of pressure versus temperature also illustrates a direct relationship. As a gas is cooled at constant volume, its pressure continually decreases until the gas condenses to a liquid (Fig. 8.43). For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant. An ideal gas is a theoretical gas composed of many randomly moving point particles that are not subject to interparticle interactions (Tuckerman, 2010). This is the only entity for which the laws, introduced by Charles, Boyle, and Avogadro apply. For a gas to be “ideal” there are four governing assumptions (Tenny and Cooper, 2021): • The gas particles have negligible volume. • The gas particles are equally sized and do not have intermolecular forces (attraction or repulsion) with other gas particles.

FIGURE 8.43 P
T curve for various single-component compounds.

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• The gas particles move randomly in agreement with Newton’s Laws of Motion. • The gas particles have perfect elastic collisions with no energy loss. In reality, there are no ideal gases. Any gas particle possesses a volume within the system (a minute amount, but present nonetheless), which violates the first assumption. Additionally, gas particles can be of different sizes; for example, hydrogen gas is significantly smaller than xenon gas. Newton’s laws do apply because underlying assumptions of Newton’s laws of motion are equally absurd. Gases in a system do have intermolecular forces with neighboring gas particles, especially at low temperatures where the particles are not moving quickly and interact with each other. Even though gas particles can move randomly, they do not have perfect elastic collisions due to the conservation of energy and momentum within the system. While ideal gases are strictly a theoretical conception, real gases can behave ideally under certain conditions. Systems with either very low pressures or high temperatures enable real gases to be estimated as “ideal.” The low pressure of a system allows the gas particles to experience less intermolecular forces with other gas particles. However, this is relative as at lower pressures, relative changes are equally important and the assertion that changes are negligible is only true in absolute value. Similarly, high-temperature systems allow for the gas particles to move quickly within the system and exhibit less intermolecular forces with each other. Therefore, for calculation purposes, real gases can be considered “ideal” in either low-pressure or high-temperature systems. By combining Charles law, Boyle’s law, and Avogadro’s law, the ideal gas law emerges PV 5 nRT

(8.27)

where P is the pressure, V is the volume, n is the amount of substance of the gas (in moles), T is the absolute temperature, and R is the gas constant, which must be expressed in units consistent with those chosen for pressure, volume, and temperature. This ideal gas law has been applied to both subatomic and nanoscales. Real fluids at low density and high temperature approximate the behavior of a classical ideal gas. However, at lower temperatures or a higher density, a real fluid deviates strongly from the behavior of an ideal gas, particularly as it condenses from a gas into a liquid or as it deposits from a gas into a solid. The Ideal Gas Law is also used for a system containing multiple ideal gases; this is known as an ideal gas mixture. With multiple ideal gases in a system, these particles are still assumed not to have any intermolecular interactions with one another. An ideal gas mixture partitions the total pressure of the system into the partial pressure contributions of each of the different gas particles. This allows for the previous ideal gas equation to be rewritten:





Pi V 5 ni R T:

(8.28)

In this equation, Pi is the partial pressure of species i and ni are the moles of species i. At low-pressure or high-temperature conditions, gas mixtures can be considered ideal gas mixtures for ease of calculation. The main issue of concern with the Ideal Gas Law is that it is not always accurate because there are no true ideal gases. The governing assumptions of the Ideal Gas Law are

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theoretical and omit many aspects of real gases. For example, the Ideal Gas Law does not account for chemical reactions that occur in the gaseous phase that could change the pressure, volume, or temperature of the system. This is a significant concern because the pressure can rapidly increase in gaseous reactions and quickly become a safety hazard. Other relationships, such as the Van der Waals Equation of State, are more accurate at modeling real gas systems. The Ideal Gas Law presents a simple calculation to determine the physical properties of a given system and serves as a baseline calculation. As studied by Christensen et al. (1992), the Ideal Gas Law can be used to calibrate anesthetic mixtures with a nominal error. At high-altitude environments, the Ideal Gas Law would be more accurate for monitoring the pressure of gas flow into patients than at sea level. If there are significant temperature fluctuations, the pressure needed to deliver oxygen to a patient must be adjusted; the Ideal Gas Law can be used as an approximation. While more sophisticated calculations offer greater accuracy overall, the Ideal Gas Law can develop physician intuition when operating with real gases. This false paradigm of “Ideal Gas Law” is also used for Energy calculations. For instance, it is used by Bose
Einstein theory, and for all the energy models, used for light therapy and high-energy radiation protocols.

8.6.1 Internal energy The other equation of state of an ideal gas must express Joule’s second law, that the internal energy of a fixed mass of ideal gas is a function only of its temperature, with U 5 U ðn; T Þ:

(8.29)

U 5 c^v nRT

(8.30)

where U is the internal energy and cˆv is the dimensionless specific heat capacity at constant volume. Heat capacity or thermal capacity is a physical property of matter, defined as the amount of heat to be supplied to an object to produce a unit change in its temperature. The SI unit of heat capacity is joule per kelvin (J/K). Heat capacity is an extensive property. Extensive properties such as the mass, volume, and entropy of systems are additive for subsystems. The corresponding intensive property is the specific heat capacity, found by dividing the heat capacity of an object by its mass. Dividing the heat capacity by the amount of substance in moles yields its molar heat capacity. The volumetric heat capacity measures the heat capacity per volume. In architecture and civil engineering, the heat capacity of a building is often referred to as its thermal mass. Note all these definitions have Dalton’s atomic theory embedded in them. Entropy is a scientific concept as well as a measurable physical property that is most commonly associated with a state of disorder, randomness, or uncertainty. The notion of entropy comes from the original paper In his 1803 paper, Fundamental Principles of Equilibrium and Movement of the French mathematician Lazare Carnot, who proposed that in any machine, the accelerations and shocks of the moving parts represent losses of moment of activity; in any natural process there exists an inherent tendency toward the dissipation of useful energy. Carnot based his views of heat partially on the early

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18th-century “Newtonian hypothesis” that both heat and light were types of indestructible forms of matter, which are attracted and repelled by other matter, and partially on the contemporary views of Count Rumford, who showed in 1789 that heat could be created by friction, as when cannon bores are machined (McCulloch, 1876). However, Carnot rejected Newton’s light and energy theory. In Carnot’s words, During all that century, the false Newtonian hypothesis, that light and heat are matter attracted or repelled by other matter, with forces analogous to gravitation or to chemical affinity, swayed the minds of scientific men.

Carnot saw merit in Huygens’ work. While Newton proposed that light was made of tiny particles known as the photons, Christian Huygens believed that light was made of waves propagating perpendicular to the direction of its movement. In 1678, Huygens proposed that every point that a luminous disturbance meets turns into a source of the spherical wave itself. The sum of the secondary waves, which are the result of the disturbance, determines what form the new wave will take. This theory of light is known as the “Huygens” principle. Using the above-stated principle, Huygens was successful in deriving the laws of reflection and refraction of light. He was also successful in explaining the linear and spherical propagation of light using this theory. However, he was not able to explain the diffraction effects of light. Later, in 1803, the experiment conducted by Thomas Young on the interference of light proved the Huygens wave theory of light to be correct. Later in 1815, Fresnel provided mathematical equations for Young’s experiment.

8.7 Subatomic representation Max Planck proposed that light is made of finite packets of energy known as a light quantum and it depends on the frequency and velocity of light. Later, in 1905, Einstein proposed that light possessed the characteristics of both particle and wave. He suggested that light is made of small particles called photons. This dual nature of light or energy, which is similar to Newton’s hypothesis, is justified with newly developed quantum theory (Fig. 8.44).

FIGURE 8.44 Electromagnetic field.

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Most of the time, light is considered to behave as a wave and it is categorized as one of the electromagnetic waves because it is made of both electric and magnetic fields. Electromagnetic fields perpendicularly oscillate to the direction of wave travel and are perpendicular to each other. As a result of which, they are known as transverse waves. A few characteristics of light are as follows, some of which are based on their own premises: • While dealing with light waves, we deal with the sine waveform. The period of the waveform is one full 0 to 360-degree sweep. • Light waves have two important characteristics known as wavelength and frequency, v 5 c/λ. The speed of light in a vacuum is assumed to be universal constant, valued at 3 3 108 m/s. This statement has two assumptions embedded in it, that are: there is such a thing as perfect vacuum, and light is not a function of anything in the medium (Khan and Islam, 2016). • The distance between the peaks of the wave is known as the wavelength. In the case of a light wave, the wavelengths are in the order of nanometers. • Frequency is the number of waves that will cross past a point in a second. • The relationship between wavelength and frequency is given by the equation: f 5 1/T • The speed of light in a vacuum is a universal constant which is 3 3 108 m/s. • As proposed by Einstein, light is made of tiny packets of energy known as photons. The formula devised by Planck determines the energy of a photon and it also shows that the energy is directly proportional to the frequency of the light. E 5 hf, where h is the Planck’s constant. With the above reasoning, the entire electromagnetic spectrum is expressed in terms of wavelengths (see Fig. 8.45). The region on this spectrum with the highest energy (so the shortest wavelengths) is gamma rays and the region with the lowest energy (so the longest wavelengths) is radio waves. The visible region of the spectrum has wavelengths from about 400 to 700 nm. The measure of wavelength determines the color on the visible spectrum. As can be seen in the figure above, a wavelength of 400 nm represents violet and a wavelength of 700 nm represents red. When all the waves are seen together, white light is seen. Next to the highenergy part of the visible region (400 nm) is ultraviolet (UV) radiation. A common example of UV radiation is sunlight. Next to the low-energy part of the visible region (700 nm) is infrared radiation (IR) (Figs. 8.46 and 8.47). The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material (Fig. 8.46). Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid state and quantum chemistry to draw inferences about the properties of atoms, molecules, and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in

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FIGURE 8.45 Electromagnetic spectrum. FIGURE 8.46 Photoelectric effect.

a delayed emission (Fig. 8.47). The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light’s intensity or duration of exposure. Because a low-frequency beam at a high intensity does not build up the energy required to produce photoelectrons, as would be the case if light’s

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FIGURE 8.47 Frequency versus kinetic energy.

energy accumulated over time from a continuous wave, Albert Einstein proposed that a beam of light is not a wave propagating through space, but a swarm of discrete energy packets, known as photons. Emission of conduction electrons from typical metals requires a few electron-volt (eV) light quanta, corresponding to short-wavelength visible or ultraviolet light. In extreme cases, emissions are induced with photons approaching zero energy, like in systems with negative electron affinity and the emission from excited states, or a few hundred keV photons for core electrons in elements with a high atomic number. Study of the photoelectric effect led to important steps in understanding the quantum nature of light and electrons and influenced the formation of the concept of wave
particle duality (Serway, 1990). Other phenomena where light affects the movement of electric charges include the photoconductive effect, the photovoltaic effect, and the photoelectrochemical effect. Diagram of the maximum kinetic energy as a function of the frequency of light on zinc. In 1905, Einstein proposed a theory of the photoelectric effect using a concept first put forward by Max Planck that light consists of tiny packets of energy known as photons or light quanta. Each packet carries energy hν that is proportional to the frequency ν of the corresponding electromagnetic wave. The proportionality constant h has become known as the Planck constant. The maximum kinetic energy Kmax of the electrons that were delivered this much energy before being removed from their atomic binding is as follows: Kmax 5 hv 2 W; v 2 vo

(8.31)

where W is the minimum energy required to remove an electron from the surface of the material. It is called the work function of the surface and is sometimes denoted Φ. If the work function is written as follows: W 5 h vo

(8.32)

The formula for the maximum kinetic energy of the ejected electrons becomes K max 5 hðv 2 vo Þ

(8.33)

Kinetic energy is positive, and ν . ν o is required for the photoelectric effect to occur. The frequency ν o is the threshold frequency for the given material. Above that frequency,

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the maximum kinetic energy of the photoelectrons as well as the stopping voltage in the experiment Vo 5

h ðv 2 vo Þ e

(8.34)

have no dependence on the number of photons and the intensity of the impinging monochromatic light. Einstein’s formula, however simple, explained all the phenomenology of the photoelectric effect, and had far-reaching consequences in the development of quantum mechanics.

8.7.1 Photoemission from atoms, molecules, and solids Electrons that are bound in atoms, molecules, and solids each occupy distinct states of well-defined binding energies. When light quanta deliver more than this amount of energy to an individual electron, the electron may be emitted into free space with excess (kinetic) energy that is hν higher than the electron’s binding energy. The distribution of kinetic energies thus reflects the distribution of the binding energies of the electrons in the atomic, molecular or crystalline system: an electron emitted from the state at binding energy EB is found at kinetic energy Ek 5 hv 2 EB . This distribution is one of the main characteristics of the quantum system, and can be used for further studies in quantum chemistry and quantum physics. The electronic properties of ordered, crystalline solids are determined by the distribution of the electronic states with respect to energy and momentum—the electronic band structure of the solid. Theoretical models of photoemission from solids show that this distribution is, for the most part, preserved in the photoelectric effect. Inner photoelectric effect in the bulk of the material that is a direct optical transition between an occupied and an unoccupied electronic state. This effect is subject to quantummechanical selection rules for dipole transitions. The hole left behind the electron can give rise to secondary electron emission, or the so-called Auger effect, which may be visible even when the primary photoelectron does not leave the material. In molecular solids, phonons are excited in this step and may be visible as satellite lines in the final electron energy. Electron propagation to the surface in which some electrons may be scattered because of interactions with other constituents of the solid. Electrons that originate deeper in the solid are much more likely to suffer collisions and emerge with altered energy and momentum. Their mean-free path is a universal curve dependent on electron’s energy. Electron escape through the surface barrier into free-electron-like states of the vacuum. In this step, the electron loses energy in the amount of the work function of the surface, and suffers from the momentum loss in the direction perpendicular to the surface. Because the binding energy of electrons in solids is conveniently expressed with respect to the highest occupied state at the Fermi energy E_F, and the difference to the free-space (vacuum) energy is the work function of the surface, the kinetic energy of the electrons emitted from solids is usually written as follows: Ek 5 hv 2 W 2 EB :

(8.35)

There are cases where the three-step model fails to explain peculiarities of the photoelectron intensity distributions. The more elaborate one-step model treats the effect as a

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coherent process of photoexcitation into the final state of a finite crystal for which the wave function is free-electron-like outside of the crystal, but has a decaying envelope inside (Sobota et al., 2021). There exists a critical frequency for every metal, ν 0 lower than which no electrons are not emitted. This describes that the kinetic energy equals the light frequency times a constant, known as Planck’s constant by the symbol h. h 5 6.63 3 10234 J

 s ’ Planck’s Constant

8.7.2 Ideal gas law in microscopic scale In order to switch from macroscopic quantities (left-hand side of the following equation) to microscopic ones (right-hand side), we use nR 5 NkB

(8.36)

PV TN

(8.37)

kB 5 where kB, Boltzmann constant P, pressure V, volume T, absolute temperature N, number of molecules of gas

kB is the Boltzmann constant (1.381 3 10223 J/K). The value of Boltzmann constant in eV is 8.6173303 3 1025 eV/K. The value of the Boltzmann constant can be expressed in various units. Table 8.3 consists of the value of k along with different units. The Boltzmann constant is introduced by Max Planck and named after Ludwig Boltzmann. It is a physical constant obtained by taking the ratio of two constants namely the gas constant and Avogadro number. Avogadro’s number is the number of units in one mole of any substance (defined as its molecular weight in grams), equal to 6.02214076 3 1023. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance and the character of the reaction. Boltzmann constant formula is as follows: k5 where

R NA

(8.38)

k is Boltzmann’s constant. NA is Avogadro number. R is the gas constant. The behavior of the gases made understanding a step closer to Planck and Boltzmann by introducing constants. The value of Boltzmann constant is mathematically expressed as follows:

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TABLE 8.3 Values of Boltzmann constant in different units. Value of k

Units

0.0083144621(75)

  eV  K erg  K Hz  K cal  K cm  K dB.WK  Hz pN  nm kJ  mol K

1.0

Atomic unit (u)

223

m2 kg.s22 K21

1.3806452 3 10

25

21

8.6173303 3 10

1.38064852 3 10216

21

21

2.0836612(12) 3 1010 224

21

3.2976230(30) 3 10

21

0.69503476(63)

21

21

2228.5991678(40) 4.10

21

21

21

FIGURE 8.48 Molecule numbers versus associated speed.

The probability distribution of particles by velocity or energy is given by the Maxwell speed distribution. Fig. 8.48 shows Maxwell’s speed distribution. The ideal gas model depends on the following assumptions: • • • • • •

The molecules of the gas are indistinguishable, small, hard spheres. All collisions are elastic and all motion is frictionless (no energy loss in motion or collision) Newton’s laws apply. The average distance between molecules is much larger than the size of the molecules. The molecules are constantly moving in random directions with a distribution of speeds. There are no attractive or repulsive forces between the molecules apart from those that determine their point-like collisions.

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• The only forces between the gas molecules and the surroundings are those that determine the point-like collisions of the molecules with the walls. • In the simplest case, there are no long-range forces between the molecules of the gas and the surroundings. The assumption of spherical particles is necessary so that there are no rotational modes allowed, unlike in a diatomic gas. The following three assumptions are very related: molecules are hard, collisions are elastic, and there are no intermolecular forces. The assumption that the space between particles is much larger than the particles themselves is of paramount importance, and explains why the ideal gas approximation fails at high pressures. Fig. 8.49 shows that the proton structure is more conducive to a cloud-like description, in which continuously smaller particles are embedded. The Boltzmann constant is used in diverse disciplines of physics. Some of them are listed below: • In classical statistical mechanics, Boltzmann constant is used to express the equipartition of the energy of an atom. • It is used to express the Boltzmann factor. • It plays a major role in the statistical definition of entropy. • In semiconductor physics, it is used to express thermal voltage. If matter is composed of protons, neutrons, electrons, quark, and gluons (Fig. 8.50). Fig. 8.8 shows scales from subatomic to megascale. In the megascale down to solar system, there is a pattern. Rutherford derived from the similarity to construct his atomic model. However, he invoked properties, previously attributed to atom (rigid, uniform, indivisible) to electrons in addition to assigning fixed orbit. Planets in the solar system do not fall under this category of matter. Also, when Bohr expanded that model more assumptions were added. For both of them, Nucleus was assumed to be a cluster of neutron and proton, both of which are once again rigid and indivisible. Even more importantly, proton and neutron were assumed to be nonorbital or stationary. As science evolved, quantum mechanics was introduced that in essence justifies any theory with

FIGURE 8.49 The proton’s structure, modeled along with its attendant fields, show that it has a finite, substantial size with smaller particles embedded in it. Source: Figure from Brookhaven National Laboratory, Siegel, 2017.

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FIGURE 8.50

Scale considerations in subatomic to mega scale.

dogmatic assertions. Quantum rules are applied to single atoms, with electrons orbiting a nucleus, come in at about the size of an Angstrom: 10210 m. The atomic nucleus itself is 100,000 times smaller than the atoms in which they are found: a scale of 10215 m. Within each individual proton or neutron, quarks and gluons are later invoked. Conventionally, sizes (implying rigid configuration) are associated with molecules, atoms, and nuclei, whereas quarks, gluons, and electrons are considered to be point-like, without any size associated with them. While this representation solves the immediate problem of filling the interparticle void, it still begs the question, what fills up the space in between rigid particles. Note that the same question was asked in matter of intergalactic space and has been answered with several versions of scientific answers. However, what fills up the void in subatomic space is not a question that is asked (Fig. 8.51). Typically, in quantum mechanics, particles are not associated with physical size, instead wavelength is cited. Wavelengths are then associated with their energy. First, there is the energy of a single photon: E 5 hv 5 hc=λ:

(8.39)

This is the Planck relation. On the other hand, we have the spectrum of light coming from a glowing hot extended object, given by Bλ 5

2hc2  hc  λ5 eλkT 2 1

(8.40)

This is Planck’s Law. All hot objects emit electromagnetic radiation but the precise frequency and wavelength of that radiation depend on the temperature of the object.

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FIGURE 8.51

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The quarks, antiquarks, and gluons of the standard model have a color charge.

FIGURE 8.52

Energy emitted per second with various

frequencies.

Let’s think about a hot lump of coal. The coal will emit a wide range of wavelengths— some visible, some ultra violet and some infrared. At high temperatures there will be a large amount of energy and much of this will be emitted in the visible part of the spectrum. As the coal cools down there will be less total energy emitted per second, less visible light and more infrared. When the temperature has fallen still further the coal will only emit infrared—on a dark night you would not be able to see it. Now, let us discuss a different scenario. The graph in Fig. 8.52 shows how the energy emitted per second by a hot object varies with wavelength and frequency. There are two lines on the graph—one shows an object at high temperature and the other the same object after it has cooled down. Notice how the

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area under the lines changes from when the object is hot to when it is cool, and also how the position of the wavelength where most energy is emitted per second moves toward the long wavelength side. Stars behave in some ways just like the lump of coal. In the constellation of Orion you can see two bright examples of hot and cold stars. The red giant Betelgeuse is a cool star while the blue giant Rigel, a really hot star, is bluish white. The surface temperature of Rigel is about 10,000 C while that of Betelgeuse is “only” about 3400 C. These are the distributions of energies (per unit time per unit area) of the many photons emitted from any object that glows. The distribution of the number of photons as a function of either frequency or wavelength allows the distinction among various elements and relates them to respective light spectra (Fig. 8.53).

FIGURE 8.53 Firework (Ash, 2015).

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The color in a firework is the result of the atoms in the fireworks reaching hot enough temperatures that the electrons inside get so excited they give off energy. This energy is emitted as light, or photons, as a result of the electron “falling” from a higher energy level to a lower one in its orbit around the atomic nucleus. The color of the light we see as a result depends on how far that electron traveled. This energy can be expressed in terms of wavelength (Fig. 8.54). When electrons in sodium atoms get excited enough to emit photons, the resulting light has a wavelength of approximately 590 nm, which is in the yellow part of the visible spectrum—so fireworks with sodium look yellow to us. Similarly, blue fireworks come from copper, green from barium, and red from strontium. The visible spectrum spans roughly 400 to 700 nm, from blue to red, so the atoms in each of these elements give off light with wavelengths corresponding to their part of the spectrum (Fig. 8.55). How is this spectrum different from the spectrum involving charcoal? The amazing thing about this process is that it’s not only responsible for explosions here on Earth, but it’s also what astronomers use to study explosions in the sky. Astronomers can infer what elements a star is made of by studying the colors in the light we collect with telescopes. By using digital cameras and instruments called spectrographs, we can see how much light is coming from a given star at each wavelength. Then, using our knowledge of chemistry and which elements emit (or conversely absorb) photons at each wavelength, we can back out what elements must be present to produce the light we see. Astronomers can do this for stars, planets, and even gas and dust clouds. In fact, spectroscopy is one of the most powerful tools astronomers have for studying the Universe. Fig. 8.56 shows the solar radiation spectrum. The relevant radiation for the applications in solar power industries lies within ultra violet (200
390 nm), visible range (390
780 nm), near-infrared (780
4000 nm), and infrared (4000
100,000 nm). The electromagnetic radiation emitted by the sun covers a very large range of wavelength from radio FIGURE 8.54 quency and color.

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FIGURE 8.55 Colors are analyzed to reconstitute composition of far off sources.

FIGURE 8.56 Solar radiation spectrum.

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waves through the infrared, visible and ultraviolet to X-rays, and gamma rays. However, 99% of the energy of solar radiation is contained in the wavelength band from 0.15 to 4 μm, comprising the near ultraviolet, visible, and near-infrared regions of the solar spectrum, with a maximum at about 0.5 μm. The variations actually observed in association with solar phenomena like sunspots, prominences, and solar flares are mainly confined to the extreme ultraviolet end of the solar spectrum and to the radio waves. Higher energy means smaller wavelength, which means we can probe smaller and more intricate structures. X-rays are high-enough in energy to probe the structure of atoms, with images from X-ray diffraction and crystallography shedding light on what molecules look like and how individual bonds look (Figs. 8.57). At even higher energies, we can get even better resolution. Particle accelerators could not only blast atomic nuclei apart, but deep inelastic scattering revealed the internal structure of the proton and neutron: the quarks and gluons lying within. It’s possible and plausible that, at some point down the road, we’ll find that some of the particles we presently think are fundamental are actually made of smaller entities themselves. Islam (2014) argued that any scientific representation must leave the open for continuously smaller particles, rather than continuously settling for a particle and calling it fundamental, the way atoms were once defined. At present, it is known that if quarks, gluons, or electrons aren’t fundamental, their structures must be smaller than 10218 to 10219 m (Fig. 8.58). Fig. 8.59 shows the perceived configuration of internal structure of a proton. Still nothing is said about what is in between? When two color-charged objects are close together, the force between them drops away to zero, like a coiled spring that isn’t stretched at all. When quarks are close together, the electrical force takes over, which often leads to a mutual repulsion. But when the color-charged objects are far apart, the strong force gets stronger. Like a

FIGURE 8.57

An electron density map of protein structure, as determined through the technique of X-ray.

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FIGURE 8.58 The quark-gluon plasma of the early Universe.

FIGURE 8.59 The internal structure of a proton, with quarks, gluons, and quark spin shown.

stretched spring, it works to pull the quarks back together. Based on the magnitude of the color charges and the strength of the strong force, along with the electric charges of each of the quarks, that’s how we arrive at the size of the proton and the neutron: where the strong and electromagnetic forces roughly balance. The above description of subatomic phenomena has enjoyed universal acceptance. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics and material science, and to the principles of information theory. It has found far-ranging

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applications in chemistry and physics, in biological systems and their relation to life, in cosmology, economics, sociology, weather science, climate change, and information systems including the transmission of information in telecommunication (Wehrl, 1978). Unfortunately, as is discussed, such description contains a number of underlying assumptions that are illogical. New formulations did not correct those assumptions, instead inserting more assumptions. In the following section, a comprehensive formulation is discussed.

8.8 Reconstituting mass and energy spectrum Khan and Islam (2016a,b) discussed the origin of the atomic and subatomic theories. They all trace back to the notion of Atomism during the time of Democritus. It originated from the ancient Greek era, when the term atom was introduced to describe what was thought to be elemental particle, which is indestructible (“atom” in Greek literally means “indestructible”). During the Islamic era of 7th to 17th century, the notion of atom being elemental particle was rejected and does not appear in any of the greatest scientists, such as Ibn Haitham, Ibn Sina, etc. The notion was revived in the early 19th century. This time, the concept of “elementary particle” underwent some changes in its meaning: notably, modern physics no longer deems elementary particles indestructible. Even elementary particles can decay or collide destructively; they can cease to exist and create (other) particles in result. While these features seem plausible, they all evolve from illogical premises that each of these theories is rooted in. In the era of quantum physics, numerous small particles have been “discovered” or hypothesized and researched: they include molecules, which are constructed of atoms, that in turn consist of subatomic particles, namely atomic nuclei and electrons. Many such particles (but not electrons) were eventually believed to be composed of even smaller particles such as quarks. Main articles: History of subatomic physics and Timeline of particle discoveries. The term “subatomic particle” is largely a retronym of the 1960s, used to distinguish a large number of baryons and mesons (which comprise hadrons) from particles that are now thought to be truly elementary. Before that hadrons were usually classified as “elementary” because their composition was unknown. A list of important “discoveries” is given in Table 8.4. Islam (2014) hypothesized that each entity has a characteristic frequency, similar to the orbital speed of various celestial bodies, including solar system.

8.8.1 Conventional classification Subatomic particles are either “elementary”, that is, not made of multiple other particles, or “composite” and made of more than one elementary particle bound together. As stated earlier, the existence of “elementary” particle has been a matter of continuous revision. These particles are first characterized by the following groupings: Quarks: the root word means “curd” in German. This word alludes to the nonrigid nature of subatomic particles. Quarks make up, amongst other things, the protons and neutrons in the nucleus. There are six “flavors” of quarks that are identified: up, down, strange, charm, bottom, and top.

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TABLE 8.4 List of “discoveries” of subatomic particles. Particle

Composition Theorized

Discovered

Comments

Electron e 2

Elementary (lepton)

G. Johnstone Stoney (1874)

J. J. Thomson (1897)

Minimum unit of electrical charge, for which Stoney suggested the name in 1891.

Alpha particle α

Composite (atomic nucleus)

Never

Ernest Rutherford (1899)

Proven by Rutherford and Thomas Royds in 1907 to be helium nuclei.

Photon γ

Elementary (quantum)

Max Planck (1900) Ernest Rutherford Albert Einstein (1905) (1899) as γ rays

Necessary to solve the thermodynamic problem of blackbody radiation.

Protonp

Composite (baryon)

William Prout (1815)

Ernest Rutherford (1919, named 1920)

The nucleus of 1H.

Neutron n

Composite (baryon)

Santiago Antu´nez de Mayolo (c.1924)

James Chadwick (1932)

The second nucleon.

Paul Dirac (1928)

Carl D. Anderson (e 1 , 1932)

Revised explanation uses CPT symmetry.

Antiparticles Pions π

Composite (mesons)

Hideki Yukawa (1935)

Ce´sar Lattes, Giuseppe Occhialini, Cecil Powell (1947)

Explains the nuclear force between nucleons. The first meson (by modern definition) to be discovered.

Muon μ 2

Elementary (lepton)

Never

Carl D. Anderson (1936)

Called a “meson” at first; but today classed as a lepton.

Kaons K

Composite (mesons)

Never

G. D. Rochester, C. C. Butler (1947)

Discovered in cosmic rays. The first strange particle.

Lambda baryons Λ

Composite (baryons)

Never

The first hyperon discovered. University of Melbourne (Λ0, 1950)

Neutrino ν

Elementary (lepton)

Wolfgang Pauli (1930), named by Enrico Fermi

Clyde Cowan, Frederick Reines

Quarks

Elementary

Murray Gell-Mann, George Zweig (1964)

No particular confirmation event for the quark model.

Charm quark c

Elementary (quark)

Sheldon Glashow, John Iliopoulos, Luciano Maiani (1970)

B. Richter et al., S. C. C. Ting et al. (1974)

Bottom quark b

Elementary (quark)

Makoto Kobayashi, Toshihide Maskawa (1973)

Leon M. Lederman et al. (1977)

Gluons

Elementary (quantum)

Harald Fritzsch, Murray Gell-Mann (1972)

DESY (1979)

Solved the problem of energy spectrum of beta decay.

(Continued)

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TABLE 8.4 (Continued) Particle

Composition Theorized

Discovered

Comments

Weak gauge bosons W 6 , Z0

Elementary (quantum)

Glashow, Weinberg, Salam(1968)

CERN (1983)

Properties verified through the 1990s.

Top quark t

Elementary (quark)

Makoto Kobayashi, Toshihide Maskawa (1973)

Fermilab (1995)

Does not hadronize, but is necessary to complete the Standard Model.

Higgs boson Elementary (quantum)

Peter Higgs et al. (1964)

CERN (2012)

Thought to be confirmed in 2013. More evidence found in 2014.

Tetraquark

Composite

?

yet to be confirmed as a tetraquark

A new class of hadrons.

Pentaquark

Composite

?

Yet another class of hadrons. As of 2019 several are thought to exist.

Graviton

Elementary (quantum)

Albert Einstein (1916)

Magnetic monopole

Elementary Paul Dirac (1931) (unclassified)

Interpretation of a gravitational wave as particles is controversial. Undiscovered

Leptons: The word comes from the Greek word, leptos, meaning “small” Leptons include electrons and neutrinos. The difference between quarks and leptons is that quarks interact with the strong nuclear force, whereas leptons do not. Six types of leptons are identified: electron, electron neutrino, muon, muon neutrino, tau, tau neutrino. Twelve gauge bosons (force carriers): In particle physics, a gauge boson is a bosonic elementary particle that acts as the force carrier for elementary fermions. Photons, W and Z bosons, and gluons are gauge bosons. All known gauge bosons have a spin of 1; for comparison, the Higgs boson has spin zero and the hypothetical graviton has a spin of 2. Therefore, all known gauge bosons are vector bosons. Gauge bosons are different from the other kinds of bosons: first, fundamental scalar bosons (the Higgs boson); second, mesons, which are composite bosons, made of quarks; third, larger composite, non-force-carrying bosons, such as certain atoms. The Higgs boson. Characterizing by mass comes from special relativity, the energy of a particle at rest equals its mass times the speed of light squared, E 5 mc2 : That is, mass can be expressed in terms of energy and vice versa. If a particle has a frame of reference in which it lies at rest, then it has a positive rest mass and is referred to as massive. As Islam (2014) pointed out, the above equation is not consistent with elementary particles being of zero mass. Composite particles are characterized by their “heaviness.” Baryons (meaning “heavy”) have greater mass than mesons (meaning “intermediate”), which in turn tend to be

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heavier than leptons (meaning “lightweight”), but the heaviest lepton (the tau particle) is heavier than the two lightest flavors of baryons (nucleons). It is also believed that any particle with an electric charge is massive. When originally defined in the 1950s, the terms baryons, mesons and leptons referred to masses; however, after the quark model became accepted in the 1970s, it was recognized that baryons are composites of three quarks, mesons are composites of one quark and one antiquark, while leptons are elementary and are defined as the elementary fermions with no color charge. All massless particles (particles whose invariant mass is zero) are elementary. These include the photon and gluon (Fig. 8.60). It is conventionally believed that most subatomic particles are not stable. All leptons, as well as baryons decay by either the strong force or weak force (except for the proton). Protons are not known to decay, although whether they are “truly” stable is unknown, as some very important Grand Unified Theories (GUTs) actually require it. The μ and τ muons, as well as their antiparticles, decay by the weak force. Neutrinos (and antineutrinos) do not decay, but a related phenomenon of neutrino oscillations is thought to exist even in vacuums. The electron and its antiparticle, the positron, are theoretically stable due to charge conservation unless a lighter particle having magnitude of electric charge # e exists (which is unlikely).

FIGURE 8.60 The photon of electromagnetism, the three W and Z bosons of the weak force, and the eight gluons of the strong force.

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All observable subatomic particles have their electric charge an integer multiple of the elementary charge. The Standard Model’s quarks have “noninteger” electric charges, namely, multiple of 1/3 e, but quarks (and other combinations with noninteger electric charge) cannot be isolated due to color confinement. For baryons, mesons, and their antiparticles the constituent quarks’ charges sum up to an integer multiple of e. Through the work of Albert Einstein, Satyendra Nath Bose, Louis de Broglie, and many others, current scientific theory holds that all particles also have a wave nature. This has been verified not only for elementary particles but also for compound particles like atoms and even molecules. In fact, according to traditional formulations of nonrelativistic quantum mechanics, wave
particle duality applies to all objects, even macroscopic ones; although the wave properties of macroscopic objects cannot be detected due to their small wavelengths. Decades ago, a Grand Unified Theory (GUT) model in particle physics was introduced. In this model, at high energies, the three gauge interactions of the Standard Model comprising the electromagnetic, weak, and strong forces are merged into a single force. Although this unified force has not been directly observed, many GUT models theorize its existence. If unification of these three interactions is possible, it raises the possibility that there was a grand unification epoch in the very early universe in which these three fundamental interactions were not yet distinct. In physics history, many premises are introduced. Examples of them are (1) existence of atom, (2) existence of quantum of energy, (3) existence of integral nature of angular momentum, (4) existence of wave mechanics, (5) existence of Black holes, (6) Black hole radiation, and so on. Another best example is Einstein’s cosmological λ term. In this chapter, authors made an attempt to understand the basic concepts of particle cosmology via five semi-empirical applications (Seshavatharam and Lakshminarayana, 2013).

8.8.2 Galaxy model Conventionally, it is said that subatomic particles do not vibrate, and they simply produce diffraction and interference patterns characteristic of their de Broglie wavelength. When they interact with matter it is said to have diffraction or interference effects. The de Broglie wavelength is deduced by these observations. It has been found that λ 5 h=p where h is Planck’s constant and p is the particle’s momentum. Few scientists have challenged this narrative (Seshavatharam and Lakshminarayana, 2013). In the galaxy model, each atomic and subatomic particle is considered to have an orbital speed. In the modern era, Rutherford was the first scientist to float the analogy of solar system to represent subatomic phenomena. He showed that most of the mass of an atom lies concentrated at its center, in a nucleus, analogous to the sun at the center of the solar system. Rutherford postulated that the atom resembled a miniature solar system, with light, negatively charged electrons orbiting the dense, positively charged nucleus, just as the planets orbit the Sun (Fig. 8.61). unlike the solar model, for which planets are different and have their own moon and miniature “solar” system, Rutherford assumed that all electrons

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FIGURE

8.61 Rutherford’s

atomic

model.

are identical rigid particles, similar to the original notion of atoms (or molecules). Later, Niels Bohr refined Rutherford’s model in 1913 by incorporating the new ideas of quantization that had been developed by the German physicist Max Planck at the turn of the century. Planck had theorized that electromagnetic radiation, such as light, occurs in discrete bundles, or “quanta,” of energy now known as photons. As discussed earlier, this quantization disconnected mass from energy. For instance, if a radioactive matter considered, it would never lose mass. Bohr postulated that electrons circled the nucleus in orbits of fixed size and energy and that an electron could jump from one orbit to another only by emitting or absorbing specific quanta of energy. During this process, energy emission is disconnected from the loss of mass. This contradicts E 5 mc2, which has its own premise of constant speed of light in a vacuum, an absurd state. More importantly, Bohr’s model violates continuity. Nevertheless, his model was widely accepted and deemed adequate in explaining atomic and subatomic phenomena. Table 8.5 summarizes major assumptions invoked by conventional scientific theories. It is accepted that subatomic particles play two vital roles in the structure of matter. They are both the basic building blocks of the universe and the mortar that binds the blocks. Any premise that involves these two aspects of physics will have most important impact on any conclusion drawn from subsequent analysis. As we have seen in the previous discussion, the dominant theories violate fundamental premises of continuity. In the matter of sizes of atomic and subatomic particles, the very question of sizes becomes a difficult proposition considering that over 99% of the overall space is “empty.” Here, “empty” does not mean there is nothing, it rather implies it is filled with matter that are not yet identified by modern scientists. That topic itself poses a challenging question.

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TABLE 8.5 Major scientists and their assumptions. Scientists

Assumptions invoked

Rutherford Uniform, rigid, electrons, in fixed orbit, stationary nucleus Planck

Discrete energy bundles radiate electromagnetically from mass, thus producing light for instance, in quanta, now known as photon, which is massless

Bohr

Electrons orbits are fixed, but electrons can jump from one orbit to another by absorbing specific quanta of energy.

At one time it was thought that large amounts of mass might exist in the form of gas clouds in the spaces between galaxies. One by one, however, the forms that this intergalactic gas might take were eliminated by direct observational searches until the only possible form that might have escaped early detection was a very hot plasma. Thus, there was considerable excitement and speculation when astronomers found evidence in the early 1970s for a seemingly uniform and isotropic background of hard X radiation (photons with energies greater than 106 electron volts). There also was a diffuse background of soft X-rays, but this had a patchy distribution and was definitely of galactic origin—hot gas produced by many supernova explosions inside the Milky Way Galaxy. The hard X-ray background, in contrast, seemed to be extragalactic, and a uniform plasma at a temperature of roughly 108 kelvins (K) was a possible source. The launch in 1978 of an imaging X-ray telescope aboard the Einstein Observatory, however, showed that a large fraction of the seemingly diffuse background of hard X-rays, perhaps all of it, could be accounted for by a superposition of previously unresolved point sources—that is, quasars. Subsequent research demonstrated that the shape of the X-ray spectrum of these objects at low redshifts does not match that of the diffuse background. The residual background has since been found to be from active galactic nuclei at higher redshifts. Today, it is believed that intergalactic medium, material found between galaxies and that mostly consists of hot, tenuous hydrogen gas. In another word, it is filled with subatomic particles. It is no surprise that sizes of subatomic particles are discussed in relative term. An atom, for instance, is typically 10210 m across, yet almost all of the size of the atom is unoccupied “empty” space available to the point-charge electrons surrounding the nucleus. Atom being more like a cloud point, the word “size” is not appropriate. This is particularly true because even nucleus and electron should have other particles associated to them. Also, smaller particles must be present within the space in between electrons and nucleus, with analogy to the intergalactic “void” discussed in the paragraph above. The distance across an atomic nucleus of average size is roughly 10214 m—only 1/10,000 the diameter of the atom. The nucleus, in turn, is made up of positively charged protons and electrically neutral neutrons, collectively referred to as nucleons, and a single nucleon has a diameter of about 10215 m—that is, about 1/10 that of the nucleus and 1/100,000 that of the atom. The sizes of atoms, nuclei, and nucleons are measured by firing a beam of electrons at an appropriate target. The higher the energy of the electrons, the farther they penetrate before being deflected by the electric charges within the atom. For example, a beam with an energy of a few hundred electron volts (eV) scatters from the electrons in a target atom.

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The way in which the beam is scattered (electron scattering) can then be studied to determine the general distribution of the atomic electrons. This process itself has several premises attached to it. For instance, it is assumed that electrons are rigid and noninteractive. As will be discussed in a follow up section. It is pointed out that the hypothesis that the electron has a diameter comparable with the wavelength of the hard γ-rays will account qualitatively for these differences, in virtue of the phase difference between rays scattered by different parts of the electron (Compton, 1919). The scattering coefficient for different wavelengths is calculated on the basis of three types of electron: (1) A rigid spherical shell of electricity, incapable of rotation; (2) a flexible spherical shell of electricity; (3) a thin flexible ring of electricity. All three types are found to account satisfactorily for the meager available data on the magnitude of the scattering coefficient for various wavelengths. The rigid spherical electron is incapable of accounting for the difference between the emergent and the incident scattered radiation, while the flexible ring electron accounts more accurately for this difference than does the flexible spherical shell electron. It is concluded that the diameter of the electron is comparable in magnitude with the wavelength of the shortest γ-rays. Using the best available values for the wavelength and the scattering by matter of hard X-rays and γ-rays, the radius of the electron is estimated as about 2 3 10210 cm. Evidence is also found that the radius of the electron is the same in the different elements. In order to explain the fact that the incident scattered radiation is less intense than the emergent radiation, the electron must be subject to rotations as well as translations. It is commonly understood that at energies of a few hundred megaelectron volts (MeV; 106 eV), electrons in the beam are little affected by atomic electrons; instead, they penetrate the atom and are scattered by the positive nucleus. Therefore, if such a beam is fired at liquid hydrogen, whose atoms contain only single protons in their nuclei, the pattern of scattered electrons reveals the size of the proton. At energies greater than a gigaelectron volt (GeV; 109 eV), the electrons penetrate within the protons and neutrons, and their scattering patterns reveal an inner structure. Thus, protons and neutrons are no more indivisible than atoms are; indeed, they contain still smaller particles, which are called quarks. Quarks cannot be characterized with today’s technology. It is estimated that they are smaller than 10218 m, or less than 1/1000 the size of the individual nucleons they form. Overall, the entire subatomic structure appears to be like a cloud, rather than a solar system, as envisioned by Rutherford. The following size distribution is proposed. Atom 10210 m. Nucleon 10215 m. Electron 10-? (point like, hence no size is considered). Quark 10218 m. Electrons and quarks contain no discernible structure; they cannot be reduced or separated into smaller components. It is therefore reasonable to call them “elementary” particles, a name that in the past was mistakenly given to particles such as the proton, which is in fact a complex particle that contains quarks. The term subatomic particle refers both to the true elementary particles, such as quarks and electrons, and to the larger particles that quarks form.

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Although both are elementary particles, electrons and quarks differ in several respects. Whereas quarks together form nucleons within the atomic nucleus, the electrons generally circulate toward the periphery of atoms. Indeed, electrons are regarded as distinct from quarks and are classified in a separate group of elementary particles called leptons. There are several types of lepton, just as there are several types of quark (see below Quarks and antiquarks). Only two types of quark are needed to form protons and neutrons, however, and these, together with the electron and one other elementary particle, are all the building blocks that are necessary to build the everyday world. The last particle required is an electrically neutral particle called the neutrino. Neutrinos do not exist within atoms in the sense that electrons do, but they play a crucial role in certain types of radioactive decay. In a basic process of one type of radioactivity, known as beta decay, a neutron changes into a proton. In making this change, the neutron acquires one unit of positive charge. To keep the overall charge in the beta-decay process constant and thereby conform to the fundamental physical law of charge conservation, the neutron must emit a negatively charged electron. In addition, the neutron also emits a neutrino (strictly speaking, an antineutrino), which has little or no mass and no electric charge. Beta decays are important in the transitions that occur when unstable atomic nuclei change to become more stable, and for this reason neutrinos are a necessary component in establishing the nature of matter. The neutrino, like the electron, is classified as a lepton. Thus, it seems at first sight that only four kinds of elementary particles—two quarks and two leptons—should exist. In the 1930s, however, long before the concept of quarks was established, it became clear that matter is more complicated. In addition to such familiar particles as the proton, neutron, and electron, studies have slowly revealed the existence of more than 200 other subatomic particles. These “extra” particles do not appear in the low-energy environment of everyday human experience; they emerge only at the higher energies found in cosmic rays or particle accelerators. Moreover, they immediately decay to the more-familiar particles after brief lifetimes of only fractions of a second. The variety and behavior of these extra particles initially bewildered scientists but have since come to be understood in terms of the quarks and leptons. In fact, only six quarks, six leptons, and their corresponding antiparticles are necessary to explain the variety and behavior of all the subatomic particles, including those that form normal atomic matter. In physics history, many premises are introduced. Examples of them are (1) existence of atom, (2) existence of quantum of energy, (3) existence of integral nature of angular momentum, (4) existence of wave mechanics, (5) existence of Black holes, (6) Black hole radiation, and so on. Another best example is Einstein’s cosmological term. In this chapter, authors made an attempt to understand the basic concepts of particle cosmology via five semi-empirical applications (Seshavatharam and Lakshminarayana, 2013). Fig. 8.62 shows the difference between Planck model and galaxy model. Note that the galaxy model does not invoke a threshold frequency for which radiation begins and it is assumed that radiation is a continuous process at all temperatures. However, the level of radiation depends on several factors, such as type of the matter, temperature, etc. In the galaxy model the assumptions of rigid, point-like configuration of electrons is replaced with each particle having a solar system-like configuration. This is depicted in

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FIGURE 8.62 Difference between Planck model and galaxy model.

FIGURE 8.63 Configuration of atomic structure in the galaxy model.

the

Fig. 8.63. Fig. 8.64 shows the actual representation of each particle at atomic and subatomic levels. In this, every particle is assumed to be like a galaxy with smaller particles orbiting around flexible orbits. Fig. 8.65 shows how a beam of electrons can be portrayed with the galaxy model. Instead of stating that only electron particles, with point like structures, are bombarded, the incoming beam is assumed to be a galaxy with high speed. At this point, it is important to discuss characteristic speed of subatomic particles. Fig. 8.1 shows characteristic speeds associated with various known structures. Note that the word “universal” applies

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FIGURE 8.64 Every particle is assumed to be like a galaxy with smaller particles orbiting around flexible orbits.

FIGURE 8.65

Photoelectric effects with the galaxy model.

to the overall movement as related to the universe, which contain numerous galaxies. The right-hand side represents tangible or directly observable bodies, whereas the left-hand side of the graph represents intangible side of physical phenomena. In this zone, matter transits to energy, for which frequency represents the characteristic speed. As discussed in Chapter 7, this frequency is inherent to every object, living or nonliving. It is also true for every level. For instance, human organs even have a characteristic frequency attached to them. In this description, no artificial barrier is used between energy and mass. It also follows that every object is radiating mass, which can be defined as “energy” with conventional physics. Such a description is possible because no assumption of zero mass is invoked for describing energy (Fig. 8.66).

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Characteristic speed for various objects.

8.8.3 Useful energy versus harmful energy When the word “energy” is used, it implies mass contained within visible light aa well as the entire energy spectrum. This fact is captured in the galaxy model, which doesn’t invoke disconnection between subatomic particles and radiative bodies. The sun is the epitome of useful energy for life on earth. The sunlight is the most important component of the process of photosynthesis. Photosynthesis is the way plants convert inorganic resources, such as sunlight, water, carbon dioxide, and minerals, into organic resources that the plant can use. The entire life cycle starts from this point on. Sunlight also provides direct energy to humans. It is the primary source of warmth, which allows human bodies to function. Also, one of the by-products of photosynthesis is oxygen, which is necessary for sustaining vital activities of all living beings, including humans. Radiation plays a particularly useful role in medical science. Ali Islam (2021) discussed the importance of using natural light in order to increase the effectiveness of light therapy. Light therapy has become a standard treatment for seasonal affective disorder (SAD) and may also be considered as an option for treating nonseasonal depression (Kuiper et al., 2013; Wirz-Justice, 1998). Light therapy is of great interest as an alternative to pharmacological treatment, and has as a research field been claimed to be active (Terman, 2007). Bright light therapy (BLT) ameliorates the symptoms of depression better as compared to placebo condition (Rosenthal et al., 1984; Kripke, 1998; Golden et al., 2005) and equally well as most other available pharmacological and non-pharmacological antidepressant treatments (Ruhrmann et al., 1998). BLT might be more attractive because it produces antidepressant benefits considerably faster (up to 50%
65% of patients experience remission within a week) than most antidepressants (Terman and Terman, 2005). In addition, treatment with BLT is more cost-efficient than several months of modern antidepressant treatment or psychotherapy and has a side- effect profile that is favorable compared to that of pharmacological antidepressants (Even et al., 2008).

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Neurodegenerative diseases (NDs) are a broad, highly heterogeneous group of disorders affecting both the central nervous system (CNS) and the peripheral nervous system and are characterized by irreversible, progressive loss of previously intact neurological function, worsening with age. It includes Alzheimer disease (AD), Parkinson disease (PD), Huntington disease (HD), motor neuron disease, and others. The pathogenesis of ND is still unclear and may vary across specific diseases. Despite significant global morbidity and mortality, there are no curative treatments for ND. ND reduces the quality of life of patients and their families. At present, the mainstay treatments of ND are pharmaceutics, but the available drugs provide only symptomatic relief and usually carry the risk of adverse reactions, such as diarrhea, nausea, headache, and others. In contrast, physical therapies and chronotherapies, such as transcranial magnetic stimulation (TMS), light therapy (LT), and physical exercise (like Tai Chi), have attracted the attention of researchers due to their high safety, low cost, and feasibility of implementation. Less known are the benefits of invisible rays that make up the energy spectrum. Each of these is used in the medical field, however, it is rarely mentioned that natural energy is beneficial whereas the artificial ones are not. A number of electromagnetic field-based technologies are available for therapeutic medical applications. These therapies can be broken down into different categories based on technical parameters employed and type of clinical application. They mostly use artificial version of the electromagnetic energy. Here are some details. Infrared therapy has many roles in the human body. These include detoxification, pain relief, reduction of muscle tension, relaxation, improved circulation, weight loss, skin purification, lowered side effects of diabetes, boosting of the immune system, and lowering of blood pressure. UVB phototherapy is generally used to treat psoriasis. Here the skin is only exposed to UVB light wavelengths between 311 and 313 nm. Another kind of light therapy is known as balneophototherapy. In these, people bathe in warm water containing specific substances for about 20 minutes. Their skin is exposed to artificial UV light while bathing, or immediately afterward. The bath often contains a solution made out of common salt or Dead Sea salt. There is also another option called “psoralen plus ultraviolet A” (PUVA) therapy. It involves exposing the skin to UVA light and using a medication known as “psoralen.” The medication makes the skin more responsive to UVA light, increasing its effect. Pulsed radio frequency energy (PRFE) therapy is a noninvasive, electromagnetic fieldbased therapeutic that is based on delivery of pulsed, shortwave radio frequency energy in the 13
27.12 MHz carrier frequency range, and designed for local application to a target tissue without the intended generation of deep heat. It has been studied for use in a number of clinical applications, including as a palliative treatment for both postoperative and nonpostoperative pain and edema, as well as in wound healing applications (Guo et al., 2011). Gamma ray is also used for certain applications. Gamma Knife radiosurgery is a type of radiation therapy used to treat tumors, vascular malformations, and other abnormalities in the brain. Gamma Knife radiosurgery is not surgery in the traditional sense because there is no incision. Instead, Gamma Knife radiosurgery uses specialized equipment to focus about 200 tiny beams of radiation on a tumor or other target with submillimeter accuracy. Although each beam has very little effect on the brain tissue it passes through, a strong

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dose of radiation is delivered to the place where all the beams meet. The precision of brain stereotactic radiosurgery results in minimal radiation delivery to healthy tissues surrounding the target. Then there are radiotherapies for cancer treatment. Radiation therapy (RT) has been one of the three pillars of cancer therapy, along with chemotherapy and surgery in both healthcare and palliative care (Li et al., 2017). Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy, with 40% curative treatment (Baskar et al., 2012). Enhancement in radiation therapy is sought-after research project in the field of medical physics. This technology has the potential of invoking revolutionary advancement in radiation therapy (Fallone, 2014). The technology, called lilac-Mr, involves the simultaneous live magnetic resonance imaging (MRI) and adaptive targeting of radiation to patients undergoing radiotherapy (RT). This study is designed to determine if exposure to the MRI-induced magnetic field (MF) influences the generation of DNA damage/repair during irradiation. Recently, this topic has received considerable attention with some of the important questions remaining unanswered (Hersh et al., 2018; Gonc¸alves et al., 2020). At present, it is believed that high energy particles entering the earth are (89%) protons—nuclei of hydrogen, the lightest and most common element in the universe—but they also include nuclei of helium (10%) and heavier nuclei (1%), all the way up to uranium. When they arrive at Earth, they collide with the nuclei of atoms in the upper atmosphere, creating more particles, mainly pions. The charged pions can swiftly decay, emitting particles called muons. Unlike pions, these do not interact strongly with matter and can travel through the atmosphere to penetrate below ground. Table 8.6 shows the Sun’s elemental composition, which is known from analysis of its spectral signature. Although the spectrum we can analyze comes from the solar photosphere and chromosphere, scientists believe it is representative of the whole Sun, except for the solar core. TABLE 8.6 Sun’s composition (Islam, 2014). Element

% of total atoms

% of total mass

Hydrogen

91.2

71.0

Helium

8.7

27.1

Oxygen

0.078

0.97

Carbon

0.043

0.40

Nitrogen

0.0088

0.096

Silicon

0.0045

0.099

Magnesium

0.0038

0.076

Neon

0.0035

0.058

Iron

0.030

0.014

Sulfur

0.015

0.040

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The balance that exists in sunlight is compromised when an artificial source of the same rays is chosen. The electromagnetic waves generated from these sources may have the same wavelength as the natural ones, but they play opposite role. With currently used energy characterization tools, the information regarding source is lost and one can no longer discern between natural energy and artificial energy. This problem is remedied with the galaxy model.

8.9 Vapor
liquid equilibria The vapor
liquid equilibrium (VLE) describes the distribution of a chemical species between the vapor phase and a liquid phase. As discussed in earlier sections of this chapter, the concentration of a vapor in contact with its liquid, especially at equilibrium, is often expressed in terms of vapor pressure, which will be a partial pressure (a part of the total gas pressure) if any other gas(es) are present with the vapor. The equilibrium vapor pressure of a liquid is in general strongly dependent on temperature. At VLE, a liquid with individual components in certain concentrations will have an equilibrium vapor in which the concentrations or partial pressures of the vapor components have certain values depending on all of the liquid component concentrations and the temperature. Conversely, if a vapor with components at certain concentrations or partial pressures is in VLE with its liquid, then the component concentrations in the liquid will be determined dependent on the vapor concentrations and on the temperature. The equilibrium concentration of each component in the liquid phase is often different from its concentration (or vapor pressure) in the vapor phase, but there is a relationship. All the existing theories start with the ideal gas law model. Then, various more approximations are introduced, each scenario describing certain configuration. The commonly used theories are: Raoult’s law: It assumes ideal mixture rule, meaning there is no interaction between molecules of two different components. The law states that the partial pressure of each component of an ideal mixture of liquids is equal to the vapor pressure of the pure component (liquid or solid) multiplied by its mole fraction in the mixture. Mathematically, Raoult’s law for a single component in an ideal solution is stated as follows: pi 5 pi xi

(8.41)

where pi is the partial pressure of the component i in the gaseous mixture above the solution, pi is the equilibrium vapor pressure of the pure component i, and xi is the mole fraction of the component i in the liquid or solid solution. Dalton’s law: As discussed before, Dalton’s law (also called Dalton’s law of partial pressures) states that in a mixture of nonreacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. This law arises from the same approximations used to describe Ideal gas law. Mathematically, it shows ptotal 5

n X i51

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where pi represents the partial pressures of each component, i. xi is the mole fraction of the ith component in the total mixture of n components. Henry’s law: Henry’s law is a gas law that states that the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid. Mathematically, C 5 kP

(8.43)

where C 5 concentration of a dissolved gas k 5 Henry’s Law constant P 5 partial pressure of the gas Table 8.7 highlights the differences between Raoult’s law and Dalton’s law. Such VLE information is useful in designing columns for distillation, especially fractional distillation, which is a particular specialty of chemical engineers. Distillation is a process used to separate or partially separate components in a mixture by boiling (vaporization) followed by condensation. Distillation takes advantage of differences in concentrations of components in the liquid and vapor phases. In mixtures containing two or more components, the concentrations of each component are often expressed as mole fractions. The mole fraction of a given component of a mixture in a particular phase (either the vapor or the liquid phase) is the number of moles of that component in that phase divided by the total number of moles of all components in that phase. Binary mixtures are those having two components. Three-component mixtures are called ternary mixtures. There can be VLE data for mixtures with even more components, but such data is often hard to show graphically. VLE data is a function of the total pressure, such as 1 atm or at the pressure the process is conducted at. When a temperature is reached such that the sum of the equilibrium vapor pressures of the liquid components becomes equal to the total pressure of the system (it is otherwise smaller), then vapor bubbles generated from the liquid begin to displace the gas that was maintaining the overall pressure, and the mixture is said to boil. This temperature is called the boiling point of the liquid mixture at the given pressure. (It is assumed that the total TABLE 8.7 Difference between Henry’s law and Raoult’s law. Henry’s law

Raoult’s law

Henry’s law states that the amount of the dissolved gas present in a liquid is proportional to the pressure of the gas.

Raoult’s law states the partial pressure of each component present in an ideal mixture of liquid is equal to the mole fraction which is multiplied by the vapor pressure.

Henry’s law is appropriate for ideal gases.

Raoult’s law is applicable to the solutions.

Henry’s law is equivalent to Henry’s constant.

Raoult’s law is equal to the vapor present in the pure component.

Henry’s law states the partial pressure of particles with low concentration.

Raoult’s law expresses that the pressure of a component with concentration is almost equal to pure liquid

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pressure is held steady by adjusting the total volume of the system to accommodate the specific volume changes that accompany boiling.) The boiling point at an overall pressure of 1 atm is called the normal boiling point of the liquid mixture.

8.9.1 Conventional classification of petroleum fluids Petroleum reservoirs are mixtures of hydrocarbon organic compounds that may be in the liquid state or in a gaseous state or in combinations of gas and liquid. The most important part of petroleum engineering for production and reservoir engineers is studying hydrocarbon phase behavior of reservoirs and characteristics of it early in the life of reservoir to suggest maximize development in the future Petroleum reservoirs can be classified into gas reservoirs, oil reservoirs, and this classification according to phase behavior diagram. This category of natural gas reservoirs is a unique type of hydrocarbon system because it has special thermodynamic behavior of the gas reservoir fluid that controlling in development. To predict the original of natural gas in place, we use many equations as material balance equations. The behavior of a reservoir fluid during production is determined by • The shape of its phase diagram. • The position of its critical point. The shapes of the phase diagrams can be used in understanding the behavior of multicomponent mixtures. As usual, current studies focus on one component, then progressively develop multicomponent models. Engle et al. (2021) constructed the methane (CH4) and ethane (C2H6) phase diagram, as applicable to the lakes of Titan. In that study, they combined laboratory work and modeling to refine the methane
ethane binary phase diagram at low temperatures and probe how the molecules interact at these conditions. They used visual inspection for the liquid phase and Raman spectroscopy for the solid. Through these methods, they determined a eutectic point of 71.15K 6 0.5K at a composition of 0.644 6 0.018 methane
0.356 6 0.018 ethane mole fraction from the liquidus data. The term “eutectic” system (from the Greek ~ ις) defines a heterogeneous mixture of substances that melts or solidifies at a ευ᾿- and τηξ single temperature that is lower than the melting point of any of the constituents. For instance, in Fig. 8.67, the eutectic point is marked by e, below which point two components (A and B) coexist as solid. On top of this point, there are solid
liquid phases with different fractions of A and B. Above the Liquidus, all liquid phases exist on both sides. The data collected in the Astrophysical Materials Lab was compared with two previously produced diagrams and is presented in Fig. 8.68. This comparison is made to experiments conducted by Moran (1959)—with best fit lines provided by Hofgartner and Lunine (2013)—and a model created by Tan and Kargel (2018). From the liquidus data, we found the methane
ethane system to have a eutectic point at a temperature of 71.15K 6 0.5K and a composition of 0.644 6 0.018 methane
0.356 6 0.018 ethane. The eutectic isotherm within the solidus was found to have a temperature of 72.2K with a standard deviation of 0.4K. This is in comparison with a calculated eutectic point of 72.6K and 0.667 methane
0.333 ethane by Tan and Kargel (2018), and 72.2K and 0.675 methane
0.325 ethane from the fit

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All Melt

1500

us TB uid q i L

TEMPERATURE (in C)

1400

Liquid us

TA

Melt + B 1300

Melt + A Solidus e

TC

1200

Crystals A + B 1100 0

A

10

20

30

40

50

60

70

80

Composition (molecular % or weight %)

90

100

B

FIGURE 8.67 Existence of eutectic point.

created by Hofgartner and Lunine (2013). As discussed below, this discrepancy in our eutectic temperatures could be attributed to the difference in time in which the sample was allowed to settle between temperature steps. Despite this, our results indicate a methane
ethane solubility that is more akin to the Tan and Kargel (2018) model as opposed to the data collected by Moran (1959). Previous studies have found the existence of three solid ethane phases between 89K and 90K at low pressures (Klimenko et al., 2008). Solid I is characterized by a plastic cubic configuration, solid II is orthorhombic, and solid III is monoclinic (Klimenko et al., 2008). We probed these transitions with Raman spectroscopy and considered the effects of both cooling and warming on the system. We found that when cooling the solid I
III transition occurs at 89.55K 6 0.2K. The warming sequence indicates the solid III
II transition occurs at 89.85K 6 0.2K and the solid II
I transition takes place at 89.65K 6 0.2K. Klimenko et al. (2008) proposed that solid II is a metastable state as they only identified it while warming the sample and not when cooling it. The lack of solid II when cooling may actually be attributed to the plastic crystalline structure of phase I (Eggers, 1975), as supercooling is common in plastic crystals (Sherwood, 1979) and has been

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FIGURE 8.68 Methane
ethane phase diagram. The black lines are modeling results from Tan and Kargel (2018), the gray diamonds are representative of data collected by Moran (1959) with the gray dashed lines being the fit created by Hofgartner and Lunine (2013). The red circles and red triangles are the liquidus and solidus data from the Astrophysical Materials Lab, respectively. Solidus data points with 1K error bars were experimentally determined within a 1K temperature step of passing the solidus, as opposed to 0.5K.

exemplified in the work of Thomas et al. (1952). The study conducted by Thomas et al. (1952) is particularly encouraging, as they found that it took approximately 12 hours for carbon tetrabromide to complete the solid I
II transition even when the sample was undercooled by 0.85K. Klimenko et al. (2008) found solid II only existed between 89.73K and 89.83K at low pressures. One of our experiments included cooling an ethane sample to approximately 89.8K and holding at that temperature for B8 hours but no apparent phase transition was witnessed. This could be for a number of reasons, one of which being that the small fluctuations in temperature in the cell may have been enough to hinder the transition. It may also be that observing the solid I
II transition when cooling is outside of the timescale we are able to obtain in the lab. A solution to this could be cooling the sample to a temperature slightly lower than the expected transition temperature to encourage a phase change on a more reasonable timescale. The caveat being that given the narrow stability range of solid II, it may be more likely that the sample would directly transition to solid III. Another option would be going to higher pressures, as this offers a wider range in temperatures at which solid II appears (Schutte et al., 1987; Shimizu et al., 1989). However, higher pressures also correlate to higher temperatures, neither of which our lab facilities are able to obtain. Ballard and Sloan (2001) presented the hydrate phase behavior of methane, ethane, propane, and water systems. Phase diagrams for the ternary and each binary

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hydrocarbon mixture with excess water have been generated at 277.6K (Bdeep sea floor temperature) using a Gibbs free energy minimization flash routine. Each pseudo-binary phase diagram (excluding water) is related to the pseudo-ternary. The main focus is the phase behavior of the pseudo-ternary hydrocarbon mixture around the incipient hydrate formation pressures at 277.6K. Phase diagrams at this temperature are presented for pressures ranging from 10 to 45 atm. Unexpected phenomena such as the coexistence of hydrate structures, solid melting on pressure increases, and several four-phase regions (Lw
sI
sII
V and Lw
sI
sII
Lhc) were encountered. Similar phenomena may exist when a real natural gas contacts water. Fig. 8.69 is the pressure versus temperature phase diagram for the methane 1 water system. Note that excess water is present so that, as hydrates form, all gas is incorporated into the hydrate phase. The phase equilibria of methane hydrates are well predicted as can be seen by a comparison of the prediction and data in Fig. 8.72. Fig. 8.70 is the pressure versus temperature phase diagram for the ethane 1 water system. Again, the predictions represent the data well, especially along the Lw
sI
V threephase equilibrium line. Note that the Lw
sI
V line intersects the Lw
V
Lhc line at and. Due to differences in the volume and enthalpy of the vapor and liquid hydrocarbon, the three-phase hydrate formation line changes from Lw
sI
V to Lw
sI
Lhc. Mathematically, this change in the three-phase hydrate formation line can be reconsidered by applying the Clapeyron equation to the phase change. Note that the hydrate formation pressure for ethane hydrates is predicted to be. Fig. 8.71 is the pressure versus temperature phase diagram for the propane 1 water system. Again, the predictions represent the data well along the Lw
sII
V equilibrium line. However, note that the data are quite scattered along the Lw
sII
Lhc line due to difficulties in measuring hydrate equilibria with three relatively incompressible phases. As with the ethane 1 water system in Fig. 8.2, the slope of the three-phase hydrate formation line changes drastically when the Lw
sII
V line intersects the Lw
V
Lhc line. In fact, the FIGURE 8.69

Pressure versus temperature diagram for methane 1 water system.

Pressure, atm

1000

Lw_sl

100 Lw_sl_V

Lw_V

10 273

275

277

279

281

283

285

287

Temperature, K

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1000

Pressure, atm

Lw_sl_Lhc Lw_sI

100

Lw_Lhc

Lw_sI_V

Lw_V_Lhc

10

Lw_V

1 273

275

277

279

281

283

285

287

289

291

Temperature, K FIGURE 8.70

Pressure versus temperature diagram for ethane 1 water system.

FIGURE 8.71

Pressure temperature behavior of propane
water system.

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Lw
sII
Lhc line is nearly vertical but comes back to lower temperature at high pressure. The predictions suggest “pseudo-retrograde” phenomena for the propane hydrates in which the sII hydrate is predicted to dissociate by pressurization at a constant temperature. For example, hydrates form at a pressure of and dissociate upon pressurization. A more detailed explanation of the pseudo-retrograde hydrate phenomena can be found in Ballard and Sloan (2001). Fig. 8.72 is the pseudo-binary pressure versus water-free composition diagram for the methane 1 propane 1 water system. The hydrate formation pressures are 4.4 and for pure propane (sII) and pure methane (sI) hydrates, respectively, as shown at the water-free composition extremes in Fig. 8.73. As methane is added to pure propane, there will be a composition at which the incipient hydrate structure changes from sII to sI. As seen in the inset of Fig. 8.76, this composition is predicted to be 0.9995 mole fraction methane in the vapor. In other words, a very small amount of propane added to pure methane gas with water will form sII hydrates. At pressures above incipient hydrate formation conditions, sII hydrates are predicted to be present throughout the entire composition range. Of the possible binary mixture combinations of methane, ethane, and propane, the methane 1 propane 1 water system (Fig. 8.73) is the simplest. Real reservoir fluids contain many more than two, three, or four components; therefore, phase-composition data can no longer be represented with two, three, or four coordinates. Instead, phase diagrams that give more limited information are used. The behavior of reservoir of a reservoir fluid during producing is determined by the shape of its phase diagram and the position of its critical point. Many of producing characteristic of each type of fluid will be discussed. Ensuing chapters will address the physical properties of these three natural gas reservoir fluids, with emphasis on retrograde gas condensate gas, dry gas, and wet gas.

FIGURE 8.72

Pressure versus temperature diagram for methane 1 propane 1 water system.

1000

Pressure, atm

Lw_sII_Lhc

100 Lw_sII

Lw_Lhc

10 Lw_sII_V

Lw_V_Lhc

Lw_V 1

273

274

275

276

277

278

Temperature, K

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Pressure, atm

41

31

21

Lw_sll Lw_sll_V

11

Lw_V 1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Mole fraction, methane FIGURE 8.73

Pseudo-P-x diagram for methane 1 propane 1 water system at 277.6K.

More recently, Michalis et al. (2015) used the direct phase coexistence method for the determination of the three-phase coexistence line of sI methane hydrates. Molecular dynamics (MD) simulations are carried out in the isothermal
isobaric ensemble in order to determine the coexistence temperature (T3) at four different pressures, namely, 40, 100, 400, and 600 bar. Methane bubble formation that results in supersaturation of water with methane is generally avoided. The observed stochasticity of the hydrate growth and dissociation processes, which can be misleading in the determination of T3, is treated with long simulations in the range of 1000
4000 ns and a relatively large number of independent runs. Statistical averaging of 25 runs per pressure results in T3 predictions that are found to deviate systematically by approximately 3.5K from the experimental values. This is in good agreement with the deviation of 3.15K between the prediction of TIP4P/Ice water force field used and the experimental melting temperature of ice Ih. These results offer the most consistent and accurate predictions from MD simulation for the determination of T3 of methane hydrates. Methane solubility values are also calculated at the predicted equilibrium conditions and are found in good agreement with continuum-scale models.

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9 Gas hydrate and its mitigation 9.1 Introduction Gas hydrates are crystalline solid, formed from water and natural gas (mainly methane). Gas hydrates appear to be like ice, but they contain huge amounts of methane. They are known to occur on every continent; they exist in huge quantities in marine sediments in a layer several 100 m thick directly below the sea floor and in association with permafrost in the Arctic. Gas hydrate is not stable at normal sea-level pressures and temperatures, which is the primary reason that it is a challenge to study. Gas hydrates are important for the following four reasons: 1. They may contain a major energy resource. 2. It may be a significant hazard because it alters sea floor sediment stability, influencing collapse and landsliding. 3. The hydrate reservoir may have a strong influence on the environment and climate, because methane is a significant greenhouse gas, although this methane will not generate unusable CO2 if burned without artificial chemical additives. 4. Pipeline plugging can occur if ambient conditions are amenable to hydrate formation. Hydrate formation can cause the bursting of the pipeline as pressure builds up after plugging. Hydrates usually exist in agglomerated solid forms that are essentially insoluble in the fluid itself. As a result, any solids in a formation or natural gas fluid are at least a nuisance for the production, handling, and transportation of these fluids. It is not uncommon for agglomerated hydrate solids (or crystals) to cause plugging and/or blockage of pipelines or transfer lines or other conduits, valves and/or safety devices, vessels, tanks, and/or other equipment, resulting in shutdown, loss of production, risk of explosion and injury or unintended release of hydrocarbons into the environment either on-land or off-shore. Accordingly, natural gas hydrates are of substantial interest as well as a concern to many industries, particularly the petroleum and natural gas industries. Gas and hydrocarbon hydrates are clathrates, and are also referred to as inclusion compounds. Clathrates are cage structures formed between a host molecule and a guest molecule. A hydrocarbon hydrate generally may be composed of crystals formed by host water molecules that surround the gas or hydrocarbon guest molecules. Without being limited to a particular understanding, the smaller or lower-boiling hydrocarbon molecules,

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particularly C1 (methane) to C4 hydrocarbons and their mixtures, are sometimes more problematic because it is believed that their hydrate or clathrate crystals are easier to form. For instance, it may be possible for ethane to form hydrates at as high as 4 C. at a pressure of about 1 MPa. If the pressure is about 3 MPa, ethane hydrates can form at as high a temperature as 14 C. Even certain nonhydrocarbons such as carbon dioxide, nitrogen, oxygen, and hydrogen sulfide are known to form hydrates under the proper conditions. Several of these nonhydrocarbons, such as carbon dioxide and nitrogen, are known to exist in produced hydrocarbon fluids and therefore present an added risk of hydrate formation. Controlling, inhibiting, and/or preventing hydrate formation, and particularly removing hydrate deposits may be a difficult, dangerous and expensive process. Presently, hydrate formation may be often controlled by using chemicals and/or active heating. Remediation of a plugged conduit often employs some combination of active heating, chemicals and/or depressurization. The use of inhibition chemicals, depressurization and/or heaters may be logistically complex and expensive and may incur a certain amount of risk to field personnel. Natural gas stream consists of methane, ethane, propane, butane and other hydrocarbons, oil and condensates, water vapor, carbon dioxide, hydrogen sulfides, nitrogen, some other gases, and solid particles. The overall attraction of natural gas as one of the biggest future sources of energy is marred by the presence of some of the most unwanted compounds as ingredients of the natural gas stream coming out of the production well. Traces of nitrogen compounds in the natural gas are believed to cause ozone layer depletion and contribute to global warming. The H2S and CO2 part of the natural gas stream is observed to decrease the heating value of natural gas thereby reducing its overall efficiency as a fuel. These gases are commonly known as acid gases and they must be removed from the natural gas before it is transported from the production well to the consumer market. Hydrogen sulfide, in particular, is a very toxic and corrosive gas that gets oxidized instantaneously in the form of sulfur dioxide and gets dispersed in the atmosphere (Basu et al., 2004). These gases render the water content in the gas stream even more corrosive. Hence, the removal of free water, water vapors, and condensates is a very important step during gas processing. The water content in the natural gas is exceptionally corrosive and it has the potential of destroying the gas transmission system. Water content in natural gas stream could get condensed and cause sluggishness in the flow. The water content could also initiate the formation of hydrates, which in turn could plug the whole pipeline system (Nallinson, 2004). Natural gas hydrates are ice-like crystalline solids, which are formed due to the mixing of water and natural gas; typically methane. In order to transform the raw natural gas stream to “line quality” gas, certain quality standards have to be maintained and the natural gas should be rid of these impurities before it could be transported through pipelines. This whole process of purification is known as the gas processing and it guards against corrosion, hydrate formation, and other environmental and safety hazards related to the natural gas transportation (Islam et al., 2010) (Fig. 9.1). The above discussion has elaborated on the importance of water content removal from the natural gas transmission stream. This would not only provide protection against the corrosion problems but the most important reason for the performance of this task is that it would help prevent the formation of hydrates in the pipeline. The discovery of the hydrates is attributed to Humphrey Davy, in the early 19th century, when he claimed that a solid material could be formed when the aqueous solution of

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Gas Oil Separator Condenser Separator Dry Gas to Pipeline

Dehydrator

A From Wellhead

Gas Stream

Contaminant Removal Nitrogen Extraction

B C

Oil

DeMethanizer

Dry Residue Gas to Pipeline

D Condensate & Free Water

E

Fractionator

Water H2S and CO2

F Nitrogen

G Natural Gas Liquids Ethane, Propane, Butane, Pentane, Natural Gas Liquids

FIGURE 9.1 Natural gas processing. Source: After Tobin, J., Shambaugh, J., Mastrangelo, E. 2006. Natural Gas Processing: The Crucial Link between Natural Gas Production and its Transportation to Market. Washington D.C., USA, Energy Information Administration. http://www.eia.doe.gov/pub/oil_gas/natural_gas/feature_articles/2006/ngprocess/ngprocess.pdf. (accessed 26.02.07).

chlorine is cooled below 9 C (Davy, 1811). These results were confirmed by Michael Faraday, who proved the existence of these solid compounds and showed that the composition of the solid is almost 1:10 for chlorine and water respectively (Faraday et al., 1823). Throughout the remainder of the 19th century, many other scientists experimented with hydrates, for example, Wroblewski, Cailletet, Woehler, Villard, de Forcrand, Schutzenberger, Cailletet, and Sully Thomas among others (Schroeder, 1926). Villard, especially, was the one who reported hydrates of methane, ethane, acetylene, and ethylene (Villard, 1888a,b). All the abovementioned researches were only of academic interest and it was not until 1934, when Hammerschmidt discovered that clathrate hydrates were responsible for plugging natural gas pipelines; especially those located in comparatively colder environments (Hammerschmidt, 1934). By the turn of the 21st century, Sloan’s work on the development of chemical additives and other methods to inhibit hydrate formation, led to the construction of the first predictive models of hydrate formation (Sloan, 1998). Natural gas hydrates have remained one of the focuses of the scientists, for the past four decades. The role of natural gas hydrates has been evaluated as (1) a future source of abundant energy, (2) a hazard to the marine geostability, and (3) a cause of change in the worldwide climate (Kvenvolden, 1993). It has already been mentioned that natural gas hydrates have been projected as one of the most promising future sources of energy. Some estimates put the sizes of the reserves in the order of magnitude, that would be enough to last for many decades, if not centuries (Kvenvolden, 1988).

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Methane hydrates were first found in nature in Siberia in 1964, and it was reported that they were being produced in the Messoyakha Field from 1970 to 1978 (Sapir et al., 1973). Another discovery was made in Mackenzie delta (Bily and Dicky, 1974), and then on the North Slope of Alaska (Collett, 1983). These and subsequent discoveries of the methane hydrates led many scientists to speculate the universal existence of huge reserves of hydrates, as the low temperature
highpressure conditions, necessary for the formation of hydrates, exist all around the globe, especially, in the permafrost and deep ocean regions. Many countries with large energy needs but limited domestic energy resources (e.g., Japan and India) have been carrying out aggressive and well-funded hydrate research and development programs to initiate the production of methane from the hydrates, on a commercial basis. These programs led to the recovery of large hydrate nodules, core collection of ocean bottom hydrate sediments, and in drilling of the wells designed specifically to investigate methane hydrate bearing strata (Max, 2000; Park et al., 1999). In the global energy outlook, where rising costs and depleting reserves of oil and future energy needs of the emerging economies are constantly extrapolated; methane hydrates are considered the most valuable future energy prospect. However, it is also hypothesized that these hydrates play a crucial role in nature; they interact with the sea bottom life forms, help restore the stability of the ocean floor, balance the global carbon cycle and affect long-term climate change (Dickens et al., 1997). These concerns have led to different researches to examine the long-term effects of the drilling the hydrates reserves for natural gas, corroborating evidences from the cores of different drilling sites (Bains et al., 1999; Katz et al., 1999; Norris and Ro¨hl, 1999). The other concerns related to the technical aspect of production of methane hydrates are the hazards posed by the hydrate-bearing sediments to the conventional oil and gas drilling operations. (Max and Dillon, 1998) Eventhough the balance between the pros and cons of exploration of gas hydrates for methane production and credibility of gas hydrates as a future source of cheap and abundant energy may take a long time to be fully established; gas hydrates remain one of the most pressing problems for natural gas transportation industry. Natural gas hydrates have been one of the potential causes for harm and damage to the natural gas transportation industry’s personal and infrastructure, respectively. Incidents have been reported when the hydrate plugs projectiles have caused loss of life and millions of dollars. It has also been documented that the natural gas hydrates plugs have adverse effects on the drilling activities, and threaten the pipelines and platform foundations (Lysne, 1995). This chapter is aimed at discussing 1. the problems caused by the formation of hydrates in natural gas transmission systems; 2. the threats they pose to natural gas transmission facilities and personnel; and 3. the proposed sustainable solutions to these problems. To date, the natural gas transportation industry has been employing different mechanical (e.g., injection of hot oil or glycol, jacketing), electrical (e.g., electric heaters), and chemical methods (e.g., injection of alcohols) to deal with this problem (Carroll, 2003). The first two methods, that is mechanical and electrical are more desirable in a sense that they are more environment friendly as compared to the chemical methods. However, the problem

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with these methods is that they become less feasible and exorbitantly costly in the presently explored gas fields in the extreme conditions of deep seas and remote permafrost locations. In the chemical hydrate inhibition methods, different chemicals such as alcohols and glycols are used. The concentrations and the volumes used for these chemicals are not fixed and are dependent upon the conditions of the environment (Weast, 1974). These chemicals are divided into different groups (e.g., thermodynamic inhibitors, kinetic inhibitors and specifically the low-dose hydrate inhibitors) on the basis of their functioning mechanisms (e.g., thermodynamic inhibitors consist of methanol and glycols). Therefore, these inhibitors are used alternately in varied circumstances and operating conditions. Though, it would be appropriate to state here that none of these inhibitors have perfect results even in conditions deemed favorable to the use of that specific kind of inhibitor. Apart from their functional ineffectiveness, almost all of them have been proven to be a detriment to the environment. They are not only hazardous in terms of physical leaks and spills, but also their mixing with natural gas has dangerous consequences for the environment in the long term. The proposition of a low-cost, universally adaptable, applicable, and environmentfriendly solution could be achieved only through a fundamental change in the way of thinking of the present scientific thinking, research, and application setup. In the present setup, it is perceived that “chemicals are chemicals,” which generally means that if the compositions of the chemicals are the same their properties in both long term and short term should be the same. This perception does not take into account the fact that the chemicals with the same chemical composition but different formation pathways could have completely different properties. “Chemicals are chemicals” is a broad generalization and it does not take numerous factors into account, such as: 1. Most of the chemicals which are produced synthetically (means man made) have been present in their natural form, in nature. In their natural form, they do not pose any threat to nature. However, almost all of these synthetically produced chemicals (claiming to be similar to the natural ones) are threatening the environment and nature (Khan and Islam, 2006a,b; Khan et al., 2006a,b). 2. It has been proved misleading and false, to state, that the synthetic chemicals, are the same as the ones that exist in nature. The argument that similarity in structure of the chemicals means similarity in their effects is also flawed (Islam et al., 2010). 3. Molecules have intricate memory, so, the path is more important than the end product (Hossain and Islam, 2006). 4. The fact that synthetic chemicals do not degrade biologically; they either get pulverized or oxidized to produce toxins (Khan and Islam, 2016). 5. The effects of pathways of man-made products and their negative impacts on human health and natural environment (Chhetri and Islam, 2006). 6. Nature is zero waste, so wasteful processes are antinature (Khan and Islam, 2012). 7. Nature is 100% efficient, so inefficient processes, their raw materials, tools, and products have tendencies to be antinature (Khan and Islam, 2012). In this context, the chemicals used by the natural gas processing industry are not congruent with nature, and natural processes, therefore the search for their alternatives is an essential task to be performed on an urgent basis. Though, the search for safer, cheaper,

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and environment friendly alternatives to the presently used chemicals should take into account the abovementioned factors. It is a fact that natural gas processing systems and processes do not recapture all the processing chemicals (considered impossible) and the natural gas at the burner of the consumer is not rid of all these chemicals. So, burning these chemicals along with the natural gas would, it is hypothesized, render this process as hazardous. These inhibiting chemicals are posing threat to the environment, when they are transported along with natural gas, and when natural gas containing these chemicals is burned. In the first case any leak would be deemed hazardous and in the latter case, the oxidation of these inhibition chemicals, when the natural gas is burned, will pose an even greater problem to the environment. This problem has the potential to damage the environment in a manner that might be beyond. In the coming years, when the rising prices of oil and the attractions of natural gas will compel the emerging economies of the world (India, China, Brazil, etc.) would be more dependent upon the natural gas as an energy source; an increased activity in the natural gas transportation sector is expected and under the present circumstances it could be speculated that the use of these inhibition chemicals would also increase correspondingly. The critique of the present system and the way the oil and gas industry is operating at the moment, relative to hydrate inhibition, may be deemed a positive step in the right direction. This pointing to the shortcomings and failings, alone could not be considered a solution in itself. It is desired to seek for the answers that are compatible with nature, which are in congruence with nature, and which will not harm it. The mechanism proposed at the end of this report is an attempt to find one of those solutions.

9.2 The importance of natural gas The earliest source of energy known to humans has been the Sun; the second one is the fire. The Sun as a source of energy has been there long before the start of the human civilization and the archeological remains of a man-made fire in Kenya; the earliest evidence suggests that humans were familiar with fire as early as 1.8 millions years ago. About 100,000 years ago the use of fire was widespread among humans throughout Africa and Asia. The water mills are mentioned in the Greek literature about 400 years B.C. (Oleson, 1984) and the windmills started appearing as early as 7th century A.D., in Persia (Windmill, 2007). Though, 150 years ago, wood was the primary source of fire (energy), it was not only a source of heating but also a source of lighting (Brain and Sillen, 1988; Gowlett et al., 1981). It is interesting to note that the time interval of 1.8 million years, till the middle of the 19th century; the major sources of energy were very nature friendly, and they did not pose threats to the nature. It was only the advent of the industrial revolution that prompted the use of the kind of energy sources, and the ways in which these sources were exploited; they have been becoming increasingly hazardous with time and have now become an ultimate threat to the stability and sustainability of nature. It was until 1850, that wood was the primary source of energy; by 1900 it was replaced by coal; and by 2000, coal has been substituted by liquid and gaseous hydrocarbons and nuclear energy. In 1850, 70% of the world total energy came from wood supplies (Bookout, 1985); in 2000, the use of wood has dropped to almost 0%. Today, the global energy sector

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is dependent on the nonrenewable fossil fuels and they are the most important source of energy. They make up roughly 85% of the total global consumption of energy, 63% of which consists of oil and natural gas and 22% of coal. Nuclear and Hydro roughly make up 8% and 7% of the remaining lot (BP, 2021). The availability of energy has transformed the course of humanity over the last few centuries. Not only have new sources of energy been unlocked—first fossil fuels, followed by a diversification to nuclear, hydropower, and now other renewable technologies—but also in the quantity we can produce and consume. The following table is based on the data sorted from the above-cited sources: (Table 9.1). Fig. 9.2 shows total energy and electricity consumption overtime. TABLE 9.1 Review by fuel type. Fuel type

1850

1900

1950

2000

2020

Wood

70

27

4







Coal

19

67

50

22

21

Oil & gas




4

38

63

64

Nuclear










8

7

Hydro and other

7

2

8

7

8

FIGURE 9.2 Energy usage since industrial revolution.

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The energy system has transformed dramatically since the Industrial Revolution. Fig. 9.2 graphs global energy consumption from 1800 onward. It is based on historical estimates of primary energy consumption from Vaclav Smil, combined with updated figures from BP’s Statistical Review of World Energy (Ritchie, 2020). Note that this data presents primary energy consumption via the “substitution method.” The “substitution method”— in comparison to the “direct method”—attempts to correct for the inefficiencies (energy wasted as heat during combustion) in fossil fuel and biomass conversion. It does this by correcting nuclear and modern renewable technologies to their “primary input equivalents” if the same quantity of energy were to be produced from fossil fuels (Fig. 9.3). Demand for energy is growing across many countries in the world, as people get richer and populations increase. One can see that global energy consumption has increased nearly every year for more than half a century. The exceptions to this are in the early 1980s, 2009 following the financial crisis, and 2021 after COVID-19 crisis.

When we look at total energy consumption, differences across countries often reflect differences in population size: countries with lots of people inevitably consume more energy than tiny countries. How do countries compare when we look at energy consumption per person? This interactive chart shows per capita energy consumption. We see vast differences across the world.

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FIGURE 9.3 Change in energy consumption over the years.

The largest energy consumers include Iceland, Norway, Canada, the United States, and wealthy nations in the Middle East such as Oman, Saudi Arabia, and Qatar. The average person in these countries consumes as much as 100 times more than the average person in some of the poorest countries. For instance, Bangladesh consumes only 2000
3000 kwh as compared to 200,000 kwh in Oman. Note that in this description, only commercially traded energy sources (such as coal, oil, gas, or grid electricity) are used, whereas in poor countries significant energy consumption occurs through traditional biomass—crop residues, wood, and other organic matter that is difficult to quantify (Figs. 9.4 and 9.5). Natural gas is projected to be a more environmentally attractive energy source, which burns efficiently and is expected to be the fuel of choice in many regions of the world. Originally, the industrial and electric power sectors were the main consumers of natural gas, but nowadays, many more energy-consuming sectors are switching to natural gas as a source of energy. For example, natural gas is increasingly used in the transportation sector in the form of compressed natural gas (CNG) and liquefied petroleum gas (LPG) for lighter vehicles, and liquefied natural gas (LNG) for heavier vehicles (Dingle and Sharp, 1994). It would be appropriate to mention here that natural gas is generally divided into two components: (1) energy components and (2) nonenergy components. The energy components largely constitute methane with smaller followed by ethane, propane, butane, and some condensates in different proportions. When natural gas is compressed at ambient temperature (15 C) to a pressure of around 3000 psi, it is called CNG and it is stored in specially designed tanks (Kojima, 2001). LNG is simply the natural gas having 85%
95% methane, 4%
10% ethane, and 1%
5% of butane, nitrogen, and water; liquefied at 2161 C and 14.7 psi (Anderson et al., 2004). LPG is mainly composed of the heavier components propane and butane, which has been liquefied at low temperatures and moderate pressures, while CNG is composed of the lighter components, methane and ethane (Dingle and Sharp, 1994). As already mentioned, natural gas is considered to be one of the most important energy sources of the future. It is being projected as an abundant and environmentally sound source of energy. Although, the lower price of natural gas, as compared to the other sources of energy, is the best reason for its relative attraction as a fuel (Table 9.2). Generally, the natural gas pricing is neither dependent on distinctive factors, nor the variations in price follow a definite a prescribed mechanism. Although, there are factors

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9. Gas hydrate and its mitigation

FIGURE 9.4 Per capita energy consumption in the world (Website 9, 2021).

including weather, residential and commercial demand, industrial demand, electric generation demand, and transportation sector demand which have a localized effect on the pricing of natural gas. Overall, a general trend of a steady increase in the price is observed, which is evident from the table below. Most recently, natural gas prices declined to multiyear lows: US Henry Hub averaged $1.99/mmBtu in 2020—the lowest since 1995, while Asian LNG prices (Japan Korea Marker) registered their lowest level on record ($4.39/mmBtu). Natural gas consumption fell by 81 billion cubic meters (bcm), or 2.3%. Nevertheless, the share of gas in primary energy continued to rise, reaching a record high of 24.7%. Declines in gas demand were led by Russia (233 bcm) and the US (217 bcm), with China (22 bcm) and Iran (10 bcm) contributing the largest increases. Interregional gas trade was reduced by 5.3%, completely accounted for by a 54 bcm (10.9%) drop in pipeline trade. LNG supply grew by 4 bcm or 0.6%, well below the 10-year average rate of 6.8% p.a. US LNG supply expanded by 14 bcm (29%), but this was partially offset by declines in most other regions, notably Europe and Africa. This steady increase in the price is considered an opportunity for investors to provide money and other resources to help construct and manage the infrastructure and systems for natural gas exploration, production, and transportation. As shown in the table the demand and the price of natural gas is rising steadily in all parts of the world but the natural gas supply and demand scenario reveal

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9.2 The importance of natural gas

653

FIGURE 9.5 Natural gas consumption per capita.

the fact that the largest consumers of natural gas are located in North America and Western Europe (e.g., Germany and France) and that the main supplier countries are located in the Middle East (e.g., Iran and UAE) and the North Sea area (e.g., United Kingdom and Norway) and the Russian Republic (Fig. 9.6). Oil continues to hold the largest share of the energy mix (31.2%). Coal is the second largest fuel in 2020, accounting for 27.2% of total primary energy consumption, a slight increase from 27.1% in the previous year. The share of both natural gas and renewables rose to record highs of 24.7% and 5.7%, respectively. Among fossil fuels, natural gas is the only one that shows a steep monotonous increase over the years. Renewables have now overtaken nuclear which makes up only 4.3% of the energy mix. Hydro’s share of energy increased by 0.4 percentage points last year to 6.9%, the first increase since 2014. It is not only at present that the industrialized countries of the western hemisphere are the main users of natural gas but the statistics show that they will be the major users in the future, too. The emerging economies of China and India are also major natural gas consumer markets and in the absence of indigenous reserves; they too, will have to import large quantities of natural gas to meet the demands of the fast-paced growth of these countries. In the same way, the natural gas exporting countries will remain the major suppliers in the future, too, and the industrialized countries will be dependent on them for meeting their future energy needs (Fig. 9.7). World-proved gas reserves decreased by 2.2
188.1 Tcm in 2020. A revision to Algeria (22.1 Tcm) provided the largest decrease, partially offset by a 0.4 Tcm increase in Canadian reserves. Russia (37 Tcm), Iran (32 Tcm), and Qatar (25 Tcm) are the countries

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TABLE 9.2 Prices of different energy commodities (BP Statistical Review, 2021). US dollars per million Btu

Japan CIFa

Japan Korea Marker (JKW)b

Average German import pricec

UK (Heren NBP Index)d

Netherlands T TF(DA Heren Index)d

US Henry Huhe

Canada (Alberta)e

OECD countries CIFf

1990

3.64




2.78







1.64

1.05

3.82

1991

3.99




3.23







1.49

0.89

3.33

1992

3.62




2.70







1.77

0.98

3.19

1993

3.52




2.51







2.12

1.69

2.82

1994

3.18




2.35







1.92

1.45

2.70

1995

3.46




2.43







1.69

0.89

2.96

1996

3.66




2.50

1.87




2.76

1.12

3.54

1997

3.91




2.66

1.96




2.53

1.36

3.29

1998

3.05




2.33

1.86




2.08

1.42

2.16

1999

3.14




1.86

1.58




2.27

2.00

2.98

2000

4.72




2.91

2.71




4.23

3.75

4.83

2001

4.64




3.67

3.17




4.07

3.61

4.08

2002

4.27




3.21

2.37




3.33

2.57

4.17

2003

4.77




4.06

3.33




5.63

4.83

4.89

2004

5.18




4.30

4.46




5.85

5.03

6.27

2005

6.05




5.83

7.38

6.07

8.79

7.25

8.74

2006

7.14




7.87

7.87

7.46

6.76

5.83

10.66

2007

7.73




7.99

6.01

5.93

6.95

6.17

11.95

2008

12.55




11.60

10.79

10.66

8.85

7.99

16.76

2009

9.06

5.28

8.53

4.85

4.96

3.89

3.38

10.41

2010

10.91

7.72

8.03

6.56

6.77

4.39

3.69

13.47

2011

14.73

14.02

10.49

9.04

9.26

4.01

3.47

18.55

2012

16.75

15.12

10.93

9.46

9.45

2.76

2.27

18.82

2013

16.17

16.56

10.73

10.64

9.75

3.71

2.93

18.25

2014

16.33

13.86

9.11

8.25

8.14

4.35

3.87

16.80

2015

10.31

7.45

6.72

6.53

6.44

2.60

2.01

8.77

2016

6.94

5.72

4.93

4.69

4.54

2.46

1.55

7.04

2017

8.10

7.13

5.62

5.80

5.72

2.96

1.58

8.97

2018

10.05

9.76

6.66

8.06

7.90

3.12

1.18

11.68

2019

9.94

5.49

5.03

4.47

4.45

2.51

1.27

10.82

2020

7.81

4.39

4.06

3.42

3.07

1.99

1.58

7.19

a

EDMC Energy Trend. S&P Global Platts r2020, S&P Global Inc. c 1986
1990 German Federal Statistical Office, 1991
2020 German Federal Office of Economics and Export Control (BAFA). d ICIS Heren Energy Ltd. e Energy Intelligence Group, Natural Gas Week. f rOECD/IEA 2020, Oil, Gas, Coal and Electricity, Quarterly Statistics http://www.iea.org/statistics. Note: CIF,cost 1 insurance 1 freight (average prices). b

656

9. Gas hydrate and its mitigation

FIGURE 9.6 Consumption of various natural resources.

with the largest reserves. The current global R/P ratio shows that gas reserves in 2020 accounted for 48.8 years of current production. The Middle East (110.4 years) and CIS (70.5 years) are the regions with the highest R/P ratio (Figs. 9.8
9.11). The transmission of natural gas from the producing countries to the consumer markets is carried out through a host of systems, for example, pipelines; and converting the natural gas into CNG, LNG, and LPG and then transporting it through special vessels built for the purpose. Natural gas fields are located in some of the remotest areas and harshest environments in the world, such as mountainous regions, deserts, and deep seas (Alaska, Siberia, Arabian deserts, and offshore North Sea). Pipelines transport natural gas from all these production sites and deliver them to the consumer market and that is the reason that pipelines are the most widely used mode of transmission of natural gas. The other two techniques require complicated and expensive installations, equipment, and vessels.

Pipelines

9.3 Natural gas hydrates

657

FIGURE 9.7 Evolution in global gas reserve in various regions (BP Statistical Review, 2021).

Technological advancements in natural gas pipelines construction industry have overcome some of the major problems in regard to the geographical terrain, environmental consideration, operating conditions, etc.; though, the rising construction and operational costs of the pipelines have barred many discovered fields from further development. The major consideration of the natural gas pipelines construction industry is to keep costs as low as possible in order to keep prices affordable to the new consumer markets and to curb the present consumer tendency to look for other still cheaper sources of energy. In this regard, the higher costs of natural gas may compel the consumers to look to explore cheaper ways to harness other more abundant sources of energy (solar, etc.) In the coming years, the construction costs will be an important factor in face of rising costs of material, labor, equipment, and increased activities in natural gas exploration, development, and transportation in these harsh and hostile environments. Though, one of the major challenges, that is, the gas hydrates problem will also have to be addressed in the earnest. It is not only a major problem in the economic sense, but it is evident that more stringent environmental laws are being enacted by the countries around the world, and this trend may ultimately lead to a total ban imposed on the use of the chemicals (methanol, etc.), used for hydrate inhibition, for the past so many decades.

9.3 Natural gas hydrates The name “Hydrate” suggests that these chemicals have water as an essential component. The structure of the natural gas hydrates, specifically the methane hydrates, is such that the methane molecule forms the center and the water molecules surrounding it, in a cage-shaped crystal, which is formed by the repetitive geometric lattice of the water molecules (von Stackelberg and Muller, 1951).

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9. Gas hydrate and its mitigation

FIGURE 9.8 Reserve/production ratio.

9.3.1 Natural gas hydrates formation Gas hydrates occur in abundance in nature, in Arctic regions and in other marine sediments. Gas hydrates are known to be crystalline solids that consist of gas molecules, generally methane, where every molecule is enclosed by a cage of water molecules. Their physical appearance is such that they look like water ice. The most abundant of these are methane hydrates. A methane molecule only contains one carbon atom and four hydrogen atoms (CH4). It is a small molecule and can form one simple type of hydrate. Solid hydrates , and structure II in pipelines are generally created in crystal forms of structure I (S-I) (S-II) , from mixtures of water and natural gas at high pressures and low temperatures. Small molecules like methane (CH4) and ethane (C2H6) form S-I type of hydrates, whereas the larger molecules such as propane and iso-butane form S-II type of hydrates.

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9.3 Natural gas hydrates

659

FIGURE 9.9 Consumption of natural gas (BP Statistical Review, 2021).

Natural gas containing propane and heavier hydrocarbons usually forms the S-II types of hydrates in the pipelines. Hydrate prevention and remediation are the most important aspect of pipeline flow assurance (Sloan, 1998). There can be many variables that manipulate the formation of hydrates, but the two main conditions for the formation of hydrates are as follows: 1. The natural gas is at a suitable pressure and temperature. 2. The natural gas is in the vicinity of its water dew point. (Carroll, 2003) There are other variables that establish the formation of hydrates, and they are kinetics, crystal formation surface, mixing, type of physical site, agglomeration, and the system’s salinity (Ebeltoft et al., 1997). The action of inhibitors is indirect in that they do not enter the hydrate phase, and do not alter its properties. Inhibitors act by modifying the thermodynamic properties of the fluid phases, in particular the aqueous liquid phase. Adding inhibitor lowers the fugacity of water thereby reducing its tendency to form hydrate (Chatti et al., 2005). Hydrates are formed when natural gas and water exist simultaneously at high pressures and lower temperatures. When a multiphase fluid stream, formed at the wellhead, gushes through under the sea pipelines, a sudden drop in its temperature occurs. This temperature drop may push the natural gas into the hydrate formation zone. The other major stage for the formation of hydrates is the shut-in and startup (Mehta et al., 2000). As these pipelines lay deep on the ocean bed, their surrounding temperatures are usually very low. So, when the production of natural gas is shut and transmission through the pipelines is closed, the temperature in the pipelines drops very quickly. As the

Pipelines

660

FIGURE 9.10

9. Gas hydrate and its mitigation

Oil trade movement (BP Statistical Review, 2021).

Pipelines

9.3 Natural gas hydrates

661

FIGURE 9.11 Major gas trade movements (BP Statistical Review, 2021).

temperature of natural gas in the pipeline drops the high pressures push the system to hydrate formation zone. If pipelines are not depressurized in time there is a strong possibility of hydrate formation (Kennedy, 1993).

9.3.2 Problems related to the formation of hydrates Natural gas hydrates present a critical problem vis-a`-vis the transmission of the natural gas through the pipelines. The hydrates form crystals that stick to the wall of the pipeline and build up huge plugs that may totally block the whole diameter of the pipelines. The result could be large monitory loses, as in some cases the whole production facilities have to be shut down. It may also threaten human life (NEB, 2004). The hydrate plugs are accelerated due to large pressure gradients across the pipeline, where they act as missiles and have the potential of destroying the production facilities and installations. This is one of the reasons the formation of hydrates in the pipelines is taken very seriously so that the normal flow of the natural gas through the pipelines is assured (Makogon, 1997; Lynch, 1996). Gas hydrates can cause restrictions and blockages in pipelines. Therefore if hydrates are identified as a potential challenge, a prevention strategy for hydrate formation and options for remediation of hydrate blockage are considered. The most commonly used means of blockage removal involves one- or two-sided depressurization with or without other options such as heating and injecting thermodynamic inhibitors. Aminnaji et al. (2017) report the use of thermodynamic inhibitors to remove a hydrate blockage in a vertical pipe.

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9. Gas hydrate and its mitigation

The experimental work was carried out using a long, cylindrical, high-pressure, vertical visual cell with full temperature gradient control. The pressure was kept relatively constant ( 6 5 bar) during multiple inhibitor injections and hydrate dissociation by batch removal of gas from the top of the cell. Fig. 9.12 shows numerical modeling results. As can be seen in this figure, this system requires some 45 mass% MEG in the aqueous phase for dissociating all hydrates. Therefore, different batches of MEG were injected from the top of the cell as listed in Table 9.3. The main reason for the injection of batches of MEG was to examine if it is possible to remove the hydrate plug with a lower amount of MEG than thermodynamic requirements, that is, it is not necessary to dissociate all hydrates to remove the blockage. The temperature and pressure of the injected MEG were the lab temperature (around 20 C) and the cell pressure, respectively. The pressure increased due to inhibitor injection and gas hydrate dissociation. To keep the pressure constant during the hydrate blockage removal process, gas was removed from the top of the cell. The volume of gas removed from the cell was measured by a gasometer at ambient conditions (depressurization was very slow to minimize temperature reduction due to the Joule Thompson effect). The system was also allowed to reach equilibrium after each inhibitor injection. Fig. 9.13 shows the pressure at the top of the cell and gas hydrate dissociation in terms of volume versus time during the hydrate blockage removal process.

190

Sll-NG, 49% MEG 5%Methanol

Sll-NG, 30% MEG

Sll-NG, 42% MEG

170 Sll-NG, 49% MEGI

Sll-NG, 35% MEG

Sll-NG, 19% MEG

Sll-NG, 25% MEG

150

Sll-NG

Sll-NG, 20% MEG

P, bar

130 110

Operating Conditions

90 70 50 30 10

-5

FIGURE 9.12

0

5

T C 10

15

20

25

Hydrate phase boundary for natural gas system with different amount of inhibitor and operat-

ing conditions.

Pipelines

663

9.3 Natural gas hydrates

TABLE 9.3 Details of thermodynamic inhibitor injection into the long windowed rig. No. of injection

Type

Mass (g)

Volume (cc)

Total mass (%)

1

MEG

230

206

10

2

MEG

230

206

19

3

MEG

230

206

25

4

MEG

220

197

30

5

MEG

228

204

35

6

MEG

400

358

42

7

MEG

450

403

49

8

Methanol

222

282

5

FIGURE 9.13 Volume of gas from hydrate dissociation in standard condition, percentage of dissociated hydrate, and pressure response due to THI injection and hydrate dissociation versus time.

The MEG gradually penetrated into the hydrates due to its higher density and ability to melt hydrates, so pressure increased. As mentioned earlier, after injecting MEG the system temperature is expected to decrease due to the endothermic nature of hydrate dissociation. The data acquisition system recorded some low temperatures (as low as 23 C) in the hydrate part of the test setup during gas hydrate dissociation, indicating the possibility of

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664

9. Gas hydrate and its mitigation

ice formation. This low temperature was observed in window 3, that is, the fact comes into fresh MEG contact with hydrates in window 3. The system temperature in each section of the setup during the chemical injection is presented in Fig. 9.14. The sharp increase in temperature of the system after each THI injection is due to the fact that the injected MEG was at ambient lab temperature, that is, this temperature rise only occurred at contact surfaces of MEG and hydrate in the system. Although depressurization process was very slow, a small temperature reduction was observed only at the top of the cell (window 6) during depressurization, indicating observed subzero temperature was not due to pressure reduction. For example, as shown in Fig. 9.14, one depressurization was conducted at B620 hour, and Fig. 9.14 shows 0.4 C reduction in the temperature which was only observed at the top of the cell (window 6). The hydrate dissociate rate after each MEG injection varies due to nonhomogenous nature of the system, for example, the hydrate dissociation rate in the early time of injection in the second and third MEG injections were 2.4 and 0.3 respectively. However, the effect of MEG gradually diminished in every single batch of MEG injection, so hydrate dissociation stopped and pressure stabilized as shown in Fig. 9.13, and the system reached an equilibrium point. In other words, in the first few hours of each MEG injection, some of hydrates dissociated and the rate of hydrate dissociation gradually decreased and finally, there was no pressure change (potentially no net hydrate dissociation). The main reasons for this behavior can be listed as follows (assuming batch gas removal is efficient in maintaining the system pressure): 1. Dilution of MEG. Hydrate dissociation results in freshwater, which could dilute the injected MEG, hence reducing its effectiveness.

FIGURE 9.14

Temperature profile for the different sections of the rig during chemical injection.

Pipelines

9.4 Prevention of hydrate formation

665

2. Nonhomogeneous MEG distribution/concentration. In the absence of any forced mixing, the MEG
water seems to remain nonhomogeneous in the limited test time, that is, high MEG concentration may not come into contact with hydrates. 3. Localized low temperature. Hydrate dissociation is endothermic which results in a reduction in local temperature, hence moving the system back to the hydrate stability zone. 4. Localized compositional variations. Again in the absence of forced mixing, there is a good possibility of nonhomogeneous gas composition.

9.4 Prevention of hydrate formation There are many techniques used for the prevention of hydrate formation in offshore pipeline systems: 1. Dehydration of natural gas. 2. Operating beyond the hydrates formation zone. 3. Addition of gas hydrate inhibitors. The first one is the complete extraction of water before the natural gas is transmitted through the pipeline. In this method, a dehydration plant is utilized, which could be installed either offshore or onshore. The major disadvantage of this method is the cost of process of installation and operation of the dehydration unit; these costs are even higher in case of the offshore plants (Hidnay and Parrish, 2006). The second method is the mechanism by which the temperature and pressure of natural gas is kept beyond the hydrates formation zone. Heat is introduced to the pipelines system, so that the fluid is maintained at a higher temperature with respect to the hydrate formation range. This is done by simply insulating the pipelines system. However, the tie back distances, the topsides capabilities of the platform and the type of fluid being transmitted should be kept in mind and that this method could not be applied universally in all cases. This model could be described as a compromise between the astronomical price tag of the insulation process, the calculated operability of the pipelines system, and the degree of acceptability of the risk level. The alternative to the insulation of the pipelines is the simple introduction of heat to the pipelines system through an external hot-water jacket, which may have numerous arrangements. Conductive or inductive heat tracing could also be used in this method. The conductive systems may not be reliable to the degree of requisite standards for different reasons. When we use an electrical heating system directly, it may consist of the feeder cable which is installed piggy back to the pipelines system being heated. When the electricity is provided, a magnetic field is created that induces electric currents in the walls of the pipelines system, which in turn generates heat. The electrical rating of the pipelines system depends upon the quantity of heat required, the material of the pipelines system and the length of the pipe. This is a very environment friendly technique for controlling the formation of hydrates in the fluid stream in the pipelines system. As there is no depressurization of the line or pigging or heating medium circulation or removal of hydrates; this method is considered to be very efficient and useful (Kennedy, 1993). However, the problem with this method is that temperature could only be manipulated to a certain limit and lowering the pressure in the

Pipelines

666

9. Gas hydrate and its mitigation

pipelines is not economically feasible, especially when natural gas has to be transmitted through long distances. Then other problem with decreasing the pressure could be that when the pressure is decreased, it might cause natural gas decompression at the wellhead. This decompression may result in decreasing the temperature of natural gas in the pipelines below freezing point and might push the system to hydrate formation regions. The abovementioned are the reasons, which render this mechanism as impractical. The third method is using certain chemicals to allow the natural gas in the transportation system to tolerate higher pressures and lower temperatures. The most widely used inhibitors include methanol and glycols. Chemical inhibitors are introduced at the wellhead and the booster stations. The addition process is carried out through positive displacement machines; therefore the process could very accurately be controlled. These chemicals are used to prevent the formation of hydrates by pushing the hydrate formation temperatures beneath the operating temperatures of the pipelines system. Although, chemical hydrate inhibition method is the most extensively used technique, the designing, production and application of a substitute cost efficient and environment friendly hydrate inhibition system should be the goal of natural gas transportation industry. The problems with this method are the unknown quantity of the inhibitors to be used, the costs of the chemicals, the unreliability of the inhibitor injection system, and the possible interaction of the hydrate inhibitors with other additives, rendering the inhibitors as ineffective (Hidnay and Parrish, 2006). The other problem with this widely used mechanism is not only in terms of leaks and spills, but also the not so obvious problems related to the oxidation of these chemicals, when natural gas is burned, could not be ignored. Despite these problems, this is one of the most attractive methods for the natural gas transportation industry. This has partly to do with the fact that this method need lower capital costs and the convenience of these systems to regulate the injection rate of the inhibitors. There are two types of chemical hydrates inhibitors, used by the gas transportation industry (Fig. 9.15): 1. Thermodynamic inhibitors. 2. Low-dosage hydrate inhibitors.

Hydrates Risk Zone

Pressure

Hydrates Zone

Pop

Hydrates Formation Curve

Hydrates Free Zone Hydrates Dissociation Curve

∆T= Subcooling

Top

Tdiss

Temperature

Pipelines

FIGURE 9.15 Schematic pressure versus temperature diagram for a gas composition. Source: After Paez, J.E., Blok, R., Vaziri, H., Islam, M.R., 2001. Problems in gas hydrates: practical Guidelines for Field Remediation. In: Presented at SPE Latin American and Caribbean Petroleum Engineering Conference, 25
28 March, Buenos Aires, Argentina.

9.4 Prevention of hydrate formation

667

9.4.1 Thermodynamic inhibitors Conventionally, methanol, ethylene glycol and triethylene glycol are the most widely used thermodynamic inhibitors; there are some inorganic salts, which are also categorized as thermodynamic inhibitors, but they are very rarely used. Thermodynamic inhibitors are chemical compounds which are added to the system in excess concentration (10%
60% by weight) to bring about change in the hydrate formation conditions. These chemicals shift the hydrate formation loci to the left of its original position which means the hydrate formation state point is pushed to a lower temperature and/or to a higher pressure (Hammerschmidt, 1939). Many aspects are evaluated before choosing a specific thermodynamic inhibitor. These aspects include capital and operating costs, the physical properties of the natural gas, safety regulations, inhibition of corrosion, the dehydration capacity of the gas, and so on. The most important issue with the selection of the inhibitors, though, is whether or not the chemical used in the process could be completely recovered from the system (the recovered chemicals are later regenerated and reinjected to the system). Methanol is a nonregenerable and comparatively cheaper thermodynamic inhibitor. Its lower price compared to the higher recovery, regeneration and re-injection costs render these processes as cost ineffective. Nonetheless, when this inhibitor is used, the unavailability of the three abovementioned processes cause a significant change in costs associated with the “lost” methanol. Methanol is used because it has lower viscosity and a lower surface tension which makes the operational separation simple (Hammerschmidt, 1939). Other chemical used for the prevention of formation of the hydrate plugs are glycols. Glycols lower the temperature range for the formation of hydrates. Among the glycols, ethylene glycol is deemed the best choice, because of its lower price, lower viscosity and lower solubility in liquid hydrocarbons. Though the problem with the Glycols is that in order for them to be effective these must be added at rates upto 100% of the weight of water. Glycols are very expensive chemicals, so, they essentially need to be recovered, and regenerated so that they can be reused in a cyclic manner. The recovery and regeneration of glycols is an additional expense and it is a space consuming option. Especially, on offshore installations, where the space is limited, the option of using glycols is a difficult and expensive choice (Kelland et al., 1995).

9.4.2 Low-dosage hydrate inhibitors These kinds of hybrid inhibitors are called low dosage hydrate inhibitors (LDHIs), because the actual dosages for these inhibitors are much lesser as compared to the thermodynamic inhibitors. It is assumed that these inhibitors bind themselves to the surface of the hydrate particles in the early stages of nucleation and do not allow them to grow to the critical size, where thermodynamic conditions become suitable for the growth of the hydrate particle. The length of the inhibition time for the Kinetic agents could be from many hours to several days and this fact is helpful in allowing the residence time of the fluids in the flowlines to be exceeded by the inhibitors. Based on their working mechanisms, these inhibitors are classified into different groups. Kinetic hydrate inhibitors (KHIs) or threshold hydrate inhibitors (THIs), increase the induction time for hydrate formation by inhibiting the same for a longer period of time. The Antiagglomerants (AA) cause a change in the agglomeration of hydrate crystals and thereby transform the hydrate Pipelines

668

9. Gas hydrate and its mitigation

particles. The surfactants type inhibitors reduce the possibility of hydrate plug formation by sticking to the pipeline (Fu et al., 2002). Though, when compared to the high operating costs, difficult supply mechanisms and health, safety and environmental hazards, that are associated with the systems using methanol and glycols, the low dosage inhibitors have not yet proved to be their alternative. There are concerns about the LDHIs that they have not yet been comprehensively subjected to the extreme conditions of some of the very harsh environments, where the oil and gas industry is operating. At most, in reservoirs where the temperatures are below the freezing point of water, and where there is no fear of hydrate formation, some kind of antifreeze is introduced into the system. In these conditions the operators use a combination of the low dosage inhibitors and the thermodynamic inhibitors (Paez et al., 2001). It should be clear that the residence time of the hydrocarbons in a pipeline should be less than the induction time of the low dosage inhibitors in the system; otherwise, the pipeline may be chocked by plugs, formed by the hydrates of the fluids. If the fluids in the pipelines are evaporated then there would be no solvent available for the inhibition process and this may pose a serious threat to the safety of the installation and personnel (Frostman et al., 2003). Another challenging situation is the shutdown process. In this process, the residence time of the fluid in the system is longer, means; the fluid has to remain in the system for a longer duration of time. Under these conditions the introduction of methanol and glycols in the system is deemed a good short term solution, and the use of low dosage inhibitors is avoided in these circumstances. In the shutdown process, the temperatures may decrease and the pressures may increase drastically and this increases the chances of formation of the hydrates. The restart is also a difficult process to handle, as in this process abnormal conditions of very high pressures and velocities need to be dealt with (Szymczak et al., 2005) It has been stated that the low dosage inhibitors may prove to be the replacement for the chemicals used presently, but the operators are not ready to take the risk of using these in the field more extensively. This problem, it is said, could be solved if there are facilities that would interpolate the experimental results with the practical, on-the-site processes. Though, for that to happen, a mechanism should be developed in order to apply the experimental results in the field, which is not in place (Fu et al., 2001). All these problems could be solved and the low dosage inhibitors could successfully replace the conventional inhibitors, but the problem is the absence of a concerted experimentation mechanism which will test and categorize all these chemicals according to their potential and effectiveness in different situations and environments. Though, it seems unlikely that in the near future the oil and gas industry is ready or willing to work for bringing about these desired changes. The most common types of LDHIs are KHIs and AAs: 1. Kinetic inhibitors (KHIs) 2. Antiagglomerants (AAs) 9.4.2.1 Kinetic hydrate Inhibitors KHIs were among the first LDHIs products employed to contain hydrates in natural gas transmission systems. The KHIs are normally water-soluble polymers or copolymers.

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9.4 Prevention of hydrate formation

669

They do not stop the formation of hydrates; they just delay the nucleation and growth of hydrates in the systems. One of the better-known KHI chemicals is a copolymer of vinylmethylacetamide (VIMA) and vinylcaprolactam (VCAP); it is also referred to as poly [VIMA/VCAP] (Fu et al., 2001). The mechanism of inhibition of natural gas hydrates through kinetic inhibitors is carried out through forcing low crystal formation by intervene with the formation of the cages. In the aqueous phase, their concentration could be in the range as low as 1% by weight, which is an advantage over thermodynamic inhibitors. The other desired property they have is that they are nonvolatile (Notz et al., 1995). The KHIs directly interact with prenucleation hydrate masses to achieve nucleation inhibition. They are believed to cause an increase in the surface energy of the prenucleation masses, which in turn increases the activation energy of nuclei formation barrier. They are said to slow down the growth of the hydrate crystal by either getting adsorbed onto the crystal surface or they fit into the crystal lattice. This is believed to cause a distortion in the hydrate crystal lattice or growth stages and hence prevent the crystals from developing rapidly into a regular crystal structure. The other major advantage of using this type of inhibition method is that it is independent of the amount of water present in the system. In case of the depletion of the reservoir, the water content increases in the product, thus these inhibitors with the longest inhibition time will have an edge over other inhibitors. However, the problems with the KHIs are that hydrate crystals eventually form even in the presence of KHI and could potentially buildup and plug the transmission system. The time that is required for the formation of hydrates depends upon, the effectiveness of the KHI, the dosage rate, and the hydrate formation driving force. In case of high subcooling, not only larger quantities of KHI are required and but it also decreases the time interval for the hydrates to form in the system. The effectiveness of the KHIs has problems that they are efficient only up to specific degrees of subcooling and pressure, if they need to be used under more strict conditions, KHIs are mixed with thermodynamic inhibitors (methanol or glycols). Kinetic inhibitors could be employed in condensates, oils, and gas
water systems. Though, these products are modified to impart most favorable operation in a particular system (Lovell and Pakulski, 2002). These inhibitors have another disadvantage and that is that the proper dosage is measured empirically and errors in the injection of the quantities of the inhibitors may increase hydrate formation rates. These inhibitors are limited to a recommended maximum subcooling (difference between the desired operating temperature and hydrate formation temperature at constant pressure) of 20 F (11 C) for these kinds, of inhibitors (Mehta and Klomp, 2005). In many cases, KHIs need a carrier chemical, for example, methanol or water. In these cases, special considerations and precautions should be taken in order to select the position of KHIs injection placements, because, in hotter spots, they have the tendency to precipitate out of the solution, and leave the system exposed to hydrate formation conditions. The carrier chemicals such as methanol could improve the chances to avoid this from happening (Lederhos et al., 1996). These kinds of inhibitors are being used in many offshore operations and it seems that they will be applied more widely as knowledge with their use increases.

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9. Gas hydrate and its mitigation

9.4.2.2 Antiagglomerants The technology of inhibiting the hydrates through Antiagglomerants was also developed in the late 1990s. Antiagglomerants stop small hydrate grains, from lumping into larger masses that have the potential of producing a plug. These inhibitors exist in the liquid hydrocarbon phase and they are more frequently used in pipelines where natural gas is dissolve in oil. These inhibitors need testing so that proper concentrations could be ensured (Hidnay and Parrish, 2006). Research and development programs are being carried out in order to create new, costeffective, and environment-friendly hydrate inhibitors that will permit multiphase fluids to be transmitted unprocessed through extended distances. These hydrate inhibitors might result in cost savings, not only in terms of lower costs of the inhibitors but also in terms of the quantity of the inhibitor injected into the system, and the pumping and storage facilities needed for the job (Frostman, 2000). It would make it possible to resize the production facilities on a more compact level. It is also claimed that this research and development will lead to the use of the kind of hydrate inhibitor technology that will also help with the ever toughening environmental regimes all around the globe. The AAs are more widely used these days, though their working mechanism is not fully comprehended. These chemicals work in presence of both water and liquid hydrocarbon phases. These chemicals work as emulsifying agents on the nuclei of the hydrates. The emulsification mechanism for antiagglomeration that is the efficiency of these chemicals depends upon the mixing process at the point of injection and it is observed to increase with the increase in the turbulence of the system. The efficiency of these chemicals will decrease if the salinity of water is high or even the water cut by volume, is high. The advantage of using these chemicals is that they work satisfactorily in severe temperatures and pressures (Frostman, 2000). Nonetheless, these research and development programs are focusing on newer chemicals or newer versions of chemicals, which are supposed to replace the present ones. At the time they are believed to the best solution possible, in terms of cost effectiveness and friendliness to the environment. Though, the chemicals, which are not yet proven detrimental to the environment, may have a potential to do harm in the long run. The basic flaw with this research methodology and approach could be attributed to the fact that it is based on the supposition that “chemicals are chemicals.” This approach is doing harm to the environment and is contradictory to the laws of nature (described in Chapter: 1). The design, research, and development of any new inhibitors should be carried out in the backdrop of the theory that it is not the chemical itself that should be considered; pathway is the most important criteria.

9.5 Problems with synthetic chemicals This section states and explores the problems with chemicals that are being used by the natural gas processing industry. Three conventional chemicals widely used by the natural gas processing industry are: ethylene glycol, methanol and monoethanolamine (MEA). All these chemicals serve the purpose of natural gas processing industry to a large extent,

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671

though all these are considered as poisons and have very harmful effects on human health (ATSDR, 1997; Morris et al., 1942). Ethylene glycol is a clear and colorless and slightly syrupy liquid at room temperature. It exists in air in the form of vapor. It is odorless, relatively nonvolatile liquid and has a sweet taste. It has a low vapor pressure and it is completely miscible in water (Cheremisinoff, 2003). There are considerable limitations of the available data on exposure and effects of ethylene glycol being oxidized with natural gas. Therefore, a definitive conclusion of ethylene glycol being toxic or nontoxic has not yet been agreed upon by the researchers. Yet, exposure in the vicinity of a point source through absorption or inhaling may exceed the tolerable intake (TI) for living organisms and pose a serious threat to human health. The kidney is the primary target site for effects of ethylene glycol but it also causes minor reproductive effects and developmental toxicity. The range and distribution of concentrations of ethylene glycol and concentrations of ethylene glycol in the vicinity of consumer point source play a major role in this regard (Laitinen et al., 1996; Paul and Kurtz, 1994; Heilmair et al., 1993). When ethylene glycol is released into the environment, it splits into surface water or groundwater. It is said that it does not accumulate in the environment, primarily due to biodegradation. Though, concerns are raised at the duration of its half-life in air, water, groundwater and soil; which are estimated to typically range from 0.35 to 3.5 days, from 2 to 12 days, from 4 to 24 days, and from 2 to 12 days, respectively. Even these conservative estimates, as in some cases half-lives may exceed these ranges depending on the environmental conditions, show that ethylene glycol released by the oxidation of natural gas, will stay in the atmosphere for days (Lokke, 1984; Evans and David, 1974; Haines and Alexander, 1975). In this backdrop, it is believed that large amounts of ethylene glycol could be fatal; in relative smaller quantities it may cause nausea, convulsions and slurred speech, disorientation, and heart and kidney problems. It may cause birth defects in the babies and reduced sperm counts in the males. It affects the chemistry of the body by increasing the amount of acid, which results in metabolic problems (Correa et al., 1996; Foote et al., 1995; Lenk et al., 1989). The EPA’s drinking water guidelines for ethylene glycol is 7000 micrograms in a liter of water for an adult and a maximum level of 127 milligrams of ethylene glycol per cubic meter of air for a 15-minute exposure is recommended by the American Conference of Governmental Industrial Hygienists. Now, about half the amount of this compound that enters the air breaks down in 24
50 hours and it breaks down within a few days to a week in water and soil. This very clearly shows that the natural gas is not as safe as it is projected to be (ATSDR, 1997). Methanol is also as harmful as ethylene glycol. It is also considered as acute poison. It is stated that the ingestion of Methanol, in significant quantities, causes nausea, vomiting, and abdomen pain. Other effects include visual symptoms including the falling visual acuity, photophobia, and the feeling of being in a snowstorm. There is increasing indications that a variety of organic solvents (including methanol) could be a cause to a Parkinsonism syndrome with pyramidal characteristics in vulnerable persons. Individuals exposed to methanol have been observed to have preferential localization of lesions within the

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9. Gas hydrate and its mitigation

putamina, which is induced by methanol. The case studies of poisoning by methanol have revealed symptoms that progress gradually to visual impairment. In case of methanol, concentrations are not always proportional to the exposure intervals owing to metabolic and other elimination manners that occur simultaneously with the exposure. The same statistics show that around 67% of the patients had hemorrhagic pancreatitis reported at postmortem. It further says that in others the seizures were observed in cases where the intoxication was severe. Still, others, who had visual symptoms, would develop irreversible visual impairment. The ingestion of as small a quantity as only 10 mL can cause blindness and 30 mL can prove to be fatal. The picture gets bleaker with the knowledge that the half-life of methanol is around 30 hours. This shows that this chemical is going to remain in the atmosphere for around 30 hours. The MEA and the diethanolamine (DEA) are also considered to be dangerous chemicals. Its contact with the lungs may result in lung injury. It causes severe irritation and more often chemical burns of the mouth, throat, esophagus, and stomach, with pain or discomfort in the mouth, throat, chest, and abdomen. It causes nausea, vomiting, diarrhea, dizziness, drowsiness, thirst, faintness, weakness, circulatory collapse, and sometimes coma. It can cause trouble breathing, could initiate chest pain, increase heart rate, set off irregular heartbeat (arrhythmia), cause a collapse, and even death. It could damage the nervous system if the exposure duration and intensity are high and it could also harm the red blood cells, which leads to anemia. It is observed to cause occupational asthma in patients involved in dealing with a cutting fluid containing diethanolamine amine. It is also observed that when male rats were made to inhale 6 ppm 25:8 mg=m3 of diethanolamine vapor for 8 hours=day and 5 days=week for 13 continuous weeks, it caused lower growth rates in the subjects. It has even caused deaths in some cases. It is observed that when the rats were exposed to drinking water containing DEA, it caused changes in their liver’s mitochondrial activity. It is believed to cause the injured area with localized discomfort or pain, severe excess redness and swelling, tissue destruction, fissures, ulceration, and possibly bleeding. In the liquid form it could cause severe irritation; experienced as discomfort or pain in the eyes. It is also noticed that it causes the eyes to blink excessively and produce tears. It causes excess redness and swelling of the conjunctiva, and chemical burns of the cornea. Kidneys and liver could be damaged by overexposure to this chemical. A skin contact with this chemical could aggravate an existing dermatitis, and inhalation of MEA could exacerbate asthma. Symptoms of higher blood pressure, salivation, and papillary dilation were reported to be associated with diethanolamine intoxication. It is believed to cause skin irritation in rabbits, when the concentration level was above 5%; a concentration level of more than 50% caused severe ocular irritation. It is reported to be corrosive to eyes, mucous membranes, and skin; and if spattered in eyes it is observed to cause extreme pain and corneal damage. In some cases, permanent eyesight loss could take place. Even lower than irritant level of repetitive contact to its vapors usually results in corneal edema and foggy vision. In the liquid form, it may cause blistering and necrosis. It is observed to cause acute coughing, pain in the chest, and pulmonary edema, if the concentration of the vapor in the surrounding atmosphere is exceedingly high. The swallowing of this chemical could cause extreme pain in intestines, called gastrointestinal pain, diarrhea, vomiting, and in some cases perforation of stomach. (ATSDR, 1997).

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9.5 Problems with synthetic chemicals

9.5.1 Pathways It is reported that upon electro-oxidation at 400 mV, methanol and glycol gives rise to glycolate, oxalate, and formate. Glycol transforms; first to glycolate and then to oxalate. Oxalate was found to be stable and no further oxidation of the same was observed. This path is termed as nonpoisoning. Another product of glycolate is formate; and this transformation is termed as poisoning path or sometimes CO poisoning path. In the case of methanol oxidation; formate was oxidized to CO2, but ethylene glycol oxidation produces CO instead of CO2 and follows the poisoning path at over 500 mV (Matsuoka et al., 2005) (Fig. 9.16). The oxidation of glycol produces glycol aldehyde as intermediate products. It is observed when heat is increased CO poisoning also increases. Wang et al. (2005) reported the oxidation of ethylene glycol on bare surface of catalyst and also under steady-state conditions. Complete oxidation of CO2 occurred less than 6%, making it a minority reaction pathway. The formation of incompletely oxidized C2 molecules indicated that breaking of C-C bonding is a slow process thus CO poisoning occurs (Matsuoka et al., 2005).

9.5.2 The processing chemicals and natural gas relationship The predictions of steep rise in the use of natural gas in coming years should be taken into consideration, and the problems related with these chemicals would be seen in real perspective. Increase in the consumption of natural gas would result in increased quantities of these harmful chemicals’ release into the atmosphere at the same ratio. Even under the present circumstances, the matter of concern with these chemicals is that they remain in the atmosphere for almost 36 hours to many days. Then the fact that methanol is never

Glyoxal

CHO2

Ethylene Glycol

Glycol Aldehyde

(CH2OH)2

CH2OH(CHO)

Glyoxylate CHO(COO)

Glycolate

CH2OH(COO)

Poisoning Path

CH2

CO

Formate HCOO

Non-Poisoning Path

Oxalate (COO)2

FIGURE 9.16 Ethylene glycol oxidation pathway in alkaline solution. Source: After Matsuoka et al. (2005).

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recovered or regenerated; the reason being the operation’s higher costs. The recovery procedures for the ethylene glycol and the MEA are not perfect and sometimes large quantities of these chemicals are transferred to the atmosphere, along with the constant discharge into the atmosphere of the chemicals that are not recovered from the natural gas. The components that are released into the atmosphere are oxidized, and they further produce other toxic chemicals. It would be appropriate to give examples for the oxidation of the abovementioned chemicals: 9.5.2.1 Ethylene glycol These are made up of three elements: carbon, oxygen, and hydrogen and their structure is H-O-CH2-CH2-O-H. If some of these molecules pick up extra oxygen, other compounds of carboxylic acid family are formed, for example, formic acid, oxalic acid, and glycolic acid5. These compounds are all acidic, and may cause corrosion of certain metals. Higher temperatures can destroy ethylene glycol in a remarkably short period of time (Carroll, 2003). 9.5.2.2 Methanol Methanol, CH3-OH, (i.e., methyl alcohol) is the simplest aliphatic alcohol and is the first member of the homologous series. It is a colorless liquid, completely miscible with water and organic solvents and is very hydroscopic. It has an agreeable odor, and a burning taste and it is a potent nerve poison (O’Leary, 2000). 9.5.2.2.1 Combustion of methanol

Methanol will burn with a pale-blue and nonluminous flame and will form carbon dioxide and steam (O’Leary, 2000): 2CH3 OH 1 3O2 $2CO2 1 4H2 O Water

Methanol

9.5.2.2.2 Oxidation of methanol

Methanol is oxidized to form formaldehyde (O’Leary, 2000): ½O

CH3 OH $ HCHO Methanol

Formaldehyde

1 H2 O water

Then formaldehyde is further oxidized to make formic acid and the same is changed to CH2 and H2O (O’Leary, 2000): ½O

½O

HCHO $ HCOOH $ CO2 1H2 O

Formaldehyde

Formic Acid

9.5.2.3 Monoethanolamine MEA degrades in the presence of oxygen and CO 2 resulting in extensive amine loss and equipment corrosion as well as generating environmental impacts.

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FIGURE 9.17 Degradation of MEA.

Rochelle and Chi (2001), in their report on Oxidative Degradation of Monoethanolamine explain the oxidation mechanism for MEA, by single electron oxidation, as follows (Fig. 9.17): 9.5.2.4 Diethanol amine DEA is a secondary amine and it contains two molecules of ethanol, linked through their carbons and it is used as an anticorrosion agent. DEA is usually produced by the reaction of ethylene oxide and ammonia in a molar ratio of 2:1. It decomposes on heating and produces toxic and corrosive gases including nitrogen oxides, carbon monoxide, and carbon dioxide. 9.5.2.5 Triethanolamine Triethanolamine (TEA) is both a tertiary amine and a tri-alcohol and has a molecule with three hydroxyl groups. TEA acts as a weak base due to the lone pair on the nitrogen atom. It also decomposes on heating and produce toxic and corrosive gases including nitrogen oxides, carbon monoxide and carbon dioxide. By-products of these reactions such as formaldehyde, nitrogen oxide, carbon dioxide, and carbon monoxide, and formic acids have other health hazards, and dangerous effects on the human health and this chain are not going to break at any stage. Keeping the above arguments in mind, it is thought that the natural gas processing and transportation industry would be earnestly looking for safer alternatives of these chemicals, but the contrary is the fact. The industry is moving very slowly, if at all, in responding to this problem. The reluctance of the oil and gas industry to switch from conventional inhibitors has many reasons. At present, the only alternatives are the low dosage inhibitors, but the problem is that these inhibitors are more suitable for milder environments in

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terms of pressure and temperature, and they would lose their efficiency in harsher environments. The use of these chemicals is not always in concord with the environmental safety standards. The need for alternatives that are safe (in all respects) and still at least as efficient as the presently used chemicals should be the goal. In the proceeding chapter, some of these hypothetical solutions are presented. One of these suggested solutions is backed up by experimental work.

9.6 Proposed solutions The proposed solutions approach the problem in two ways. One is the production of the same conventional chemicals such as methanol, ethylene amine, MEA, DEA, and TEA from reactants that are present in nature. The other is getting rid of the presently used conventional chemicals (as described above), altogether and use alternates, which are taken from nature. The suggested solutions, if proved applicable and practical, would not only eliminate the toxicity but also help decrease the costs of the overall process.

9.6.1 First approach The first approach is hypothetical but it is believed that this could be proved a practical solution, with elaborate experimental work. This approach would not alter the present mechanisms and methodology of applying conventional chemicals in processing and transportation of natural gas, it would only make a change to the pathways in the development of the same chemical. This approach is based on the theory that natural chemicals are inherently useful whereas artificial ones are the opposite (Islam et al., 2010). As such, true sustainability is with natural materials. It is believed that if the constituents of the conventional inhibitors are taken from innocuous natural sources, their toxicity will decrease if not diminish altogether. 9.6.1.1 Ethylene glycol As suggested above, if the process and ingredients of ethylene glycol production would involve only those substances that are found in the nature, the produced ethylene glycol could prove to be less toxic and cease to be as dangerous as it is today. Examining the main chemical reaction in the process, it is observed: 1 H2 O - HO-CH2 -OH C2 H4 1 O- C2 H4 O ðEthyleneÞ ðEthylene OxideÞ ðWaterÞ ðEthylene GlycolÞ This reaction shows that if ethylene from a source, natural or otherwise, is oxidized, it will convert to ethylene oxide. The introduction of water to ethylene oxide will change it to ethylene glycol. If ethylene is taken from a natural source, the resulting ethylene oxide and eventually the ethylene glycol will not be as toxic. There are numerous sources of ethylene in nature that can be obtained from various fruits and vegetables. The list of fruits and vegetables that could be a source of ethylene is given in Table 9.4 (Table 9.4).

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9.6 Proposed solutions

TABLE 9.4 Ethylene sensitivity chart. Perishable commodities

Temperature (C / F)

Ethylene production

Apple (nonchilled)

1.1 / 30

VH

Apple (chilled)

4.4 / 40

VH

Apricot

2 0.5 / 31

H

Artichoke

0 / 32

VL

Asian pear

1.1 / 34

H

Asparagus

2.2 / 36

VL

Avocado (California)

3.3 / 38

H

Avocado (tropical)

10.0 / 50

H

Banana

14.4 / 58

M

Beans (lima)

0 / 32

L

Beans (snap/green)

7.2 / 45

L

Belgian endive

2.2 / 36

VL

Berries (blackberry)

20.5 / 31

L

Berries (blueberry)

20.5 / 31

L

Berries (cranberry)

2.2 / 36

L

Berries (currants)

20.5 / 31

L

Berries (dewberry)

20.5 / 31

L

Berries (elderberry)

20.5 / 31

L

Berries (gooseberry)

20.5 / 31

L

Berries (loganberry)

20.5 / 31

L

Berries (raspberry)

20.5 / 31

L

Berries (strawberry)

20.5 / 31

L

Breadfruit

13.3 / 56

M

Broccoli

0 / 32

VL

Brussel sprouts

0 / 32

VL

Cabbage

0 / 32

VL

Cantalope

4.4 / 40

H

Cape gooseberry

12.2 / 54

L

Carrots (topped)

0 / 32

VL

Casaba melon

10.0 / 50

L

Fruits and vegetables

(Continued)

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TABLE 9.4 (Continued) Perishable commodities

Temperature (C / F)

Ethylene production

Cauliflower

0 / 32

VL

Celery

0 / 32

VL

Chard

0 / 32

VL

Cherimoya

12.8 / 55

VH

Cherry (sour)

20.5 / 31

VL

Cherry (sweet)

21.1 / 30

VL

Chicory

0 / 32

VL

Chinese gooseberry

0 / 32

L

Collards

0 / 32

VL

Crenshaw melon

10.0 / 50

M

Cucumbers

10.0 / 50

L

Eggplant

10.0 / 50

L

Endive (escarole)

0 / 32

VL

Feijoa

5.0 / 41

M

Figs

0 / 32

M

Garlic

0 / 32

VL

Ginger

13.3 / 56

VL

Grapefruit (AZ, CA, FL, TX)

13.3 / 56

VL

Grapes

2 1.1 / 30

VL

Greens (leafy)

0 / 32

VL

Guava

10 / 50

L

Honeydew

10 / 50

M

Horseradish

0 / 32

VL

Jack fruit

13.3 / 56

M

Kale

0 / 32

VL

Kiwi fruit

0 / 32

L

Kohlrabi

0 / 32

VL

Leeks

0 / 32

VL

Lemons

12.2 / 54

VL

Lettuce (butterhead)

0 / 32

L

Lettuce (head/iceberg)

0 / 32

VL (Continued)

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9.6 Proposed solutions

TABLE 9.4 (Continued) Perishable commodities

Temperature (C / F)

Ethylene production

Lime

12.2 / 54

VL

Lychee

1.7 /35

M

Mandarine

7.2 / 45

VL

Mango

13.3 / 56

M

Mangosteen

13.3 / 56

M

Mineola

3.3 / 38

L

Mushrooms

0 / 32

L

Nectarine

20.5 / 31

H

Okra

10.0 / 50

L

Olive

7.2 / 45

L

Onions (dry)

0 / 32

VL

Onions (green)

0 / 32

VL

Orange (CA, AZ)

7.2 / 45

VL

Orange (FL, TX)

2.2 / 36

VL

Papaya

12.2 / 54

H

Paprika

10.0 / 50

L

Parsnip

0 / 32

VL

Parsley

0 / 32

VL

Passion fruit

12.2 / 54

VH

Peach

20.5 / 31

H

Pear (Anjou, Bartlett/ Bosc)

1.1 / 30

H

Pear (prickley)

5.0 / 41

N

Peas

0 / 32

VL

Pepper (bell)

10.0 / 50

L

Pepper (Chile)

10.0 / 50

L

Persian melon

10.0 / 50

M

Persimmon (Fuyu)

10.0 / 50

L

Persimmon (Hachiya)

0.5 / 41

L

Pineapple

10.0 / 50

L

Pineapple (guava)

5.0 / 41

M

Plantain

14.4 / 58

L (Continued)

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9. Gas hydrate and its mitigation

TABLE 9.4 (Continued) Perishable commodities

Temperature (C / F)

Ethylene production

Plum/prune

20.5 / 31

M

Pomegranate

5.0 / 41

L

Potato (processing)

10.0 / 50

VL

Potato (seed)

4.4 / 40

VL

Potato (table)

7.2 / 45

VL

Pumpkin

12.2 / 54

L

Quince

20.5 / 31

L

Radishes

0 / 32

VL

Red beet

2.8 / 37

VL

Rambutan

12.2 / 54

H

Rhubard

0 / 32

VL

Rutabaga

0 / 32

VL

Sapota

12.2 / 54

VH

Spinach

0 / 32

VL

Squash (hard skin)

12.2 / 54

L

Squash (soft skin)

10.0 / 50

L

Squash (summer)

7.2 / 45

L

Squash (Zucchini)

7.2 / 45

N

Star fruit

8.9 / 48

L

Swede (Rhutabaga)

0 / 32

VL

Sweet corn

0 / 32

VL

Sweet potato

13.3 / 56

VL

Tamarillo

0 / 32

L

Tangerine

7.2 / 45

VL

Taro root

7.2 / 45

N

Tomato (mature/green)

13.3 / 56

VL

Tomato (Brkr/Lt Pink)

10.0 / 50

M

Tree-tomato

3.9 / 39

H

Turnip (roots)

0 / 32

VL

Turnip (greens)

0 / 32

VL

Watercress

0 / 32

VL (Continued)

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9.6 Proposed solutions

TABLE 9.4 (Continued) Perishable commodities

Temperature (C / F)

Ethylene production

Watermelon

10.0 / 50

L

Yam

13.3 / 56

VL

Cut flowers (carnations)

0 / 32

VL

Cut flowers (chrysanthemums)

0 / 32

VL

Cut flowers (Gladioli)

2.2 / 36

VL

Cut flowers (roses)

0 / 32

VL

Potted plants

22.8
18.3 / 27
65

VL

Nursery stock

21.1
4.4 / 30
40

VL

Christmas trees

0 / 32

N

7.2
15 / 45
59

VL

Live plants

Flowers bulbs (bulbs/ corms/ rhizomes/tubers)

N, None; H, High; L, Low; M, Medium; VH, Very High; VL, Very Low.

9.6.1.2 Monoethanolamine The reaction between ammonia and ethylene oxide yields to produce monoethanolamine, the subsequent reaction between monoethanolamine and ethylene oxide produces diethanolamine and reaction between diethanolamine and ethylene oxide results in the production of TEA. In the initial reaction, the sources of ammonia and ethylene oxide could be either synthetic or natural. It is suggested that ethylene oxide from natural sources as described in the abovementioned processes be allowed to react with aqueous ammonia (from urine, etc.) in liquid phase without catalyst at a temperature range of 50
100C and 1
2 MPa pressure. A reaction would result in the production of monoethanolamine, which if allowed to proceed further would produce diethanolamine and TEA. The ethylene oxide and ammonia from natural sources, it is hypothesized, would render the product as nontoxic, the whole process environment friendly and the by-products of the reactions unharmful and nontoxic as they are now. NH3 ðAmmoniaÞ

1

C2 H4 O - ðC2 H4 OHÞNH2 Monoethanolamine ðEthylene OxideÞ

ðC2 H4 OHÞNH2 1 ðMonoethanolamineÞ

- ðC2 H4 OHÞ2 NH C2 H4 O ðDiethanolamineÞ ðEthylene OxideÞ

ðC2 H4 OHÞ2 NH 1 ðDiethanolamineÞ

C2 H4 O - ðC2 H4 OHÞ3 N ðTriethanolamineÞ ðEthylene OxideÞ

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9.6.2 Second approach The second approach is based on the hypothesis that natural biological means could be employed by the industry in processing and transportation of natural gas. Mokhatab et al. (2004) have shown that this hypothesis could be validated. Paez (2001) reported results of bacteria, extracted and cultured from sewage water, alleviated the hydrate problem significantly. One of the reasons is that it is theorized that hydrocarbon lumps in the gas pipelines would work as a source of food for the bacteria from the sewage water, and the bacteria will act the way the LDHIs work. 9.6.2.1 Hydrate formation prevention through biological means The possibilities of completely replacing the present toxic chemicals (used by the gas processing and transportation industry) with substances that are found in nature are immense. It is already been elaborated upon that along with the chemical composition the pathways should always be considered; if the source of the substance is extracted from nature, the satisfaction with the pathway is guaranteed. The increased activity in natural gas exploration, production, processing, and transportation areas has increased the awareness of the general public regarding the environmental issues. It is believed that, in future, as the concerns about the toxicity of currently used inhibitors would grow, the environmental consciousness of the consumers would demand major changes to the presently used systems and chemicals. The industry’s approach in this regard has only been to focus on minimizing the wastage and increasing recovery and regeneration of the presently used inhibitors. However, it is feared that if the root cause of the problem, means the toxicity issue with the presently used chemicals is not addressed; the current situation is only going to last and cause further damage to the environment. It is essential that the presently used inhibitors are replaced only by the ones that conform to the first and foremost benchmark, that is, the condition that they are considered safe and would not pose any threat to the environment. The inhibitors proposed in this report conform to the above condition as these are taken from nature as they are; therefore no artificial, man-made synthetic changes have been made to them. These inhibition systems are intended to be very low-cost, environmentfriendly, nontoxic and safe. It would be appropriate to mention here that the use of the micro-organisms in natural gas industry is not new and it has been used by the industry in certain fields, for example, in the bio-remediation of the contaminated soil and water and in the enhanced oil recovery. Though, the same industry has never used the biological means for the inhibition of hydrates. The simple logic that hydrates (which contain hydrocarbons) be considered as food and the bacteria as the consumer, is the base of this theory and this logic would help devise a mechanism that would facilitate resolving the problem of the hydrates in natural gas industry. It has already been mentioned, that extensive experimental work is needed to be carried out in order to verify this theory. The experiments described in this report have been carried out in controlled environment in a lab. In order for these experiments’ results to be in concord with the intended goals, it was necessary that the bacteria would have to be able to survive the severe, inhospitable, and harsh environment associated with the

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formation of hydrates. Though, the experiments described in this report would be using common bacteria, found in the sewage water; as to confirm the positive results got by Paez (2001); the future work on these experiments will be carried out with extremophiles. Extremophiles are the bacteria that live, survive, and grow in extremely harsh conditions. The extremophiles remain active in the conditions that are described as inhospitable for other organisms and the characteristics that allow them to do so are being studied around the developed world. New extremophiles are being discovered and the already identified ones are experimented upon. Amongst the humongous number of extremophiles, the ones that are needed for the future experiments would be chosen from the category of barophilic and psycrophiles. These barophilic and psycrophilic bacteria thrive under high pressures and low temperatures and they have been identified as having an optimal growth rate in the range of 60 MPa and 15 C. This pressure range could be higher in some cases and could reach a mark of 80 MPa for the Barophile bacteria, as evident from the discovery of DB21MT-2 and DB21MT-5 by scientists in Japan. Other significant discoveries were Shewanella benthica and Moritella in the barophilic categories (Bohlke et al., 2002; Kato et al., 1998). 9.6.2.2 Reaction mechanisms of barophiles and psycrophiles Researchers have been focusing on the reaction mechanisms of these bacteria, under very high-pressure conditions. It has been hypothesized that these bacteria regulate the structure of their membranes’ fatty acids to handle these pressures. There are proteins, called Omph, that have the best possible growth environment at high pressures where they have an increased ability to take nutrients from the surrounding. The genetic studies of some of these bacteria show that all these barophiles are composed of different DNAbinding factors that vary according to the varying pressure and environment conditions. These findings led to the culturing of some of the bacteria that exist in the high-pressure zones in the vicinity of 50 MPa (Kato and Bartlett, 1997). As mentioned above, the Psycrophiles are bacteria that have the property of surviving in the very cold temperatures. This property would be needed in the bacteria that would be used in the experimental work in future. Unfortunately, Psycrophiles are the bacteria that researchers have very little knowledge of, as opposed to their cousins, thermopiles, which have a history of research carried out on them. However, it is hypothesized that these organisms regulate the fatty acid arrangement of the phospholipids of the membrane, in reaction to the changes in the temperatures. When the temperature decreases, the composition of the fatty acid in the membrane also changes from a very disordered gellike material to a very orderly form of a liquid crystal. There are also signs that the Proteins’ flexibility plays a part in the ability of these organisms to withstand these very low temperatures. These activities are the result of the biochemical reactions that involve the enzymatic catalysis (Cummings et al., 2004). The efficiency of these reactions is considerably reduced at low temperatures, as the thermodynamic forces also play a certain role in this process. Though, the enzymes found in these organisms are more efficient in their manipulations of the metabolic activity. These types of bacteria have been taken from permafrost (temperatures in the range of 5 C) and deep sea environments (depths in the range of 2000 m) (Rossi et al., 2003).

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9.6.2.3 Bacteria growth and survival requirements The types of bacteria needed to carry out the future experimental work, have been described above. Now, the growth and the survival requirements for them are described in the following paragraphs. These organisms need the nutrients to feed on, the optimal levels of the presence of or absence of oxygen, the availability of water, optimal states of temperatures, etc. Nutrients are usually the need of a specific cell in terms of food and it could be carbon, nitrogen, phosphorous, and sulphur. These needs are dependent upon various factors but usually, these organisms take upsugars, carbohydrates, hydrocarbons, carbon dioxide, and some inorganic salts. The need for the energy is evident for these systems to survive, so, these organisms either make energy by their own or by the processing the light. Sometimes they process different chemicals, present in the environment for the same purpose. As far as the need of water for the survival of these organisms is concerned, suffice it to say that almost 80% of the total mass of bacteria is water, although these organisms can tolerate the absence of water in certain conditions. The matter of presence or absence of oxygen is dealt with by different bacteria in different ways. There are bacteria that would live in the presence of oxygen only. Then there are bacteria types that would live in the absence of oxygen only. There are other bacteria types that would basically live in an environment where there is oxygen, though they have the ability to survive in the absence of it. Still, other bacteria types are there, that would live in the absence of oxygen but they could also survive in the presence of oxygen. These are called obligate aerobes, obligate anaerobes, facultative anaerobes, and facultative aerobes, respectively. 9.6.2.4 Experimental apparatus The picture of the experimental apparatus is given in the Fig. 9.18. The apparatus consisted of a hollow cylinder with openings on one ends, while a piston was located at the other. The piston was welded to the cylinder walls for this stage of the experiments. A reinforced window (made of composite material), secured by screws, was located at the hollow end. This window allowed the observation of the state of the system inside the cylinder. There

FIGURE 9.18

Cylinder for experiment.

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were three holes through the walls of the cylinder, right below the “window end,” named as “A, B, and C.” Hole “A” was attached to a one-way valve through a reinforced pipe. The one-way valve allowed the entrance of methane into the cylinder, but prevented the methane from coming out of it. This valve also had a manual shut-off knob for emergency purposes (Fig. 7.4). The other end of the valve was connected to pressure gauges, through the reinforced pipe. The pressure gauges were in turn connected to the methane tank, through a lefthanded coupler (Fig. 9.19). The main pressure gauges which were attached to the methane tank are shown in Fig. 9.20. On the combination gauges; one of the gauges showed the pressure inside the methane tank and the other showed the pressure inside the cylinder (Fig. 9.21). There was a knob on the face of the gauges plate, which, upon screwing in allowed the methane to pass into the cylinder. Hole “B” was used for introducing the bacteria samples into the cylinder. It had a screw for opening and closing of the hole. Hole “C” had another pressure gage attached to the cylinder with a ball valve, in between. The ball valve could be opened and shut instantaneously. This particular pressure gage too, showed the pressure inside the cylinder. This arrangement was necessary because when the cylinder was brought to a desired methane pressure, the ball valve could be shut and the pressure gage could be taken out for safety reasons (see Fig. 9.22 for the whole arrangement). The piston in the cylinder had a hydraulic Jack secured right behind it; for the purpose of manual application of pressure. Though, in this particular set of experiments, the pressure inside the methane tank was relied upon to pressurize the work fluid inside the cylinder (Fig. 9.23). 9.6.2.4.1 Preparation of samples

Three samples of different compositions were used in three of the four experiments. In the first experiment, only water was used with the methane system, so that the conditions of formation of hydrates could be observed. The three samples were prepared as follows: Sample 1 The sample was composed of distilled water and sewage drops in the ratio of 10:1. Distilled water was used in all these sample preparation processes. The growth of bacteria was observed for 48 hours and the bacteria count was made as in the procedure described earlier.

FIGURE 9.19 Window end of the cylinder.

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FIGURE 9.20

Main pres-

sure gauges.

FIGURE 9.21

Methane

tank assembly.

Sample 2 This sample was composed of distilled water, sewage drops, and crude oil drops in the ratio of 100:10:5. The growth of bacteria was observed for 48 hours and the bacteria count was made at the end of the period, according to the procedure described earlier.

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FIGURE

9.22

Cylinder

assembly.

FIGURE 9.23 Cylinder and hydraulic jack.

Sample 3 This sample consisted of distilled water, agar media, and the sewage drops. The agar media was added as a nutrient for bacteria. 9.6.2.4.2 Bacteria counting

The image analysis system has been one of the most promising bacteria-counting procedure (Livingston and Islam, 1999). The accuracy of this system has been evident from its matching results with those of the microscope enumeration. Besides, this system has been very user friendly and with little practice and experience, a user might make very accurate readings of bacteria count, without resorting to much sophisticated alternatives. The images thus acquired could be enhanced for manipulation and stored onto a storage media for an indefinite period of time. (Livingston and Islam, 1999) Computer image analyzer The image analysis system used in these experiments consists of 1. Ziess 459310; the image analyzer,

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Axio-Cam; a high-resolution video camera, An optical microscope; with magnification of 1000X, An image processor, A Pentium PC, with two softwares: a. Axio-Vision; high-resolution image monitor, b. KS300; a high-resolution text monitor (Chaalal and Islam, 2001)

Axio-Vision has the ability to control and contrast the brightness and color of images. It allows the correction of lighting conditions and controls white balance as well. Other features of this tool are various processes for enhancing focus and emphasizing details-noise suppression shooting contour enhancement. The main objective of this software is to obtain as clear an image as possible for the microscope so it can be later analyzed using KS300 software. KS300 is an image processing and analyzing software that permits fast and accurate measurement of morphological and densitometric parameters. It also has the ability to recognize the contrast of different colors including gray (with a very high sensitivity), which allows to study both “black and white” and colored images (Fig. 9.24). Computer image analyzer slide and cover For each experiment, 1 drop of samples was placed on the slide and the glass cover was then placed on the samples to provide a flat surface for optimum microscope observation. Bacteria-counting procedure The theoretical procedure for carrying out bacteria-counting process in these experiments is described here. One drop of each sample was placed on a slide and then covered with a glass cover slip with dimensions: 22 3 30 mm (Fig. 9.25): Acircle 5 πð2Þ2 Acircle 5 4π Area of the cover plate 5 Acs 5 22 3 30 .Acs 5 660 mm2 FIGURE 9.24

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FIGURE 9.25 Cover slide and the circle. Cover Slide Circle, d=2 mm

22 mm

30 mm

An image analyzer was employed for direct counting of the bacteria. Bacteria were counted from the image of a circle on the cover slide of diameter of 2 mm, Fig. 9.25. Counting was made for “n” circles on the cover slide and the average was used as the number of bacteria in each circle: Na 5

ðN1 1 N2 1

          1 Nn Þ n

where Na 5 Average number of bacteria in each circle, Nn 5 Number of bacteria in circle 0 n0 , and n 5 Total number of circles in which becteria have been counted. At the end of the process, the reading of total bacteria count was converted to another unit, that is, bacteria count=mL. The average number of bacteria in each circle was multiplied by the ratio of the cover slide area to the area of circle to give rise to the total number of bacteria under the cover slide:  Acs Na Ncs 5 Ap  660 Ncs 5 Na 4π Ncs 5 ð52:52ÞNa

ðwhere π 5 3:14159Þ

where Ncs 5 Number of bacteria under each cover slide, Acs 5 Area of cover slide, and Ap 5 Area of each circle. For measurement purposes, a Pasteur pipette was used in these experiments, wherein each mL of water contained 40 drops. So the total number of bacteria, under each cover slide would be multiplied by 40 to give rise to a number of bacteria count in mm. Ncs 5 Number of bacteria under each cover slide Nml 5 40 Ncs Nml 5 Number of bacteria per ml The total number of bacteria in the sample would be determined, as follows: N 5 V s 3 N ml where N 5 Total bacteria count in the entire sample and Vs 5 Total volume of the sample

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9.6.2.4.3 Experimental procedure

The experimental procedure started with the introduction of a prescribed volume of the sample into the cylinder through Hole “B” and then the screw was tightened halfway in it. The methane was then allowed inside the cylinder via the reinforced pipe from the methane tank, with the screw in Hole “B” still half open. Methane was allowed to enter into the cylinder through the one-way valve mounted on Hole “A” and would be made to leave through Hole “B.” The high-pressure entry and simultaneous high-pressure exit of methane are intended to flush all the air from inside the cylinder. The presence of air inside the cylinder under high pressure is considered extremely dangerous in terms of safety, as it has the potential to cause an explosion. The screw on Hole “B” was tightened, once it was assured that all the air was taken out of the cylinder. Then the pressure was allowed to slowly build up, as methane was allowed to enter the cylinder. The knobs on the methane tank and gage assembly connected to the tank were used for shutting off the supply of methane, once it reached the desired pressure value. After the system reached a pressure of 300 psi, the methane supply was stopped by shutting off the knobs on both the methane tank and the two-gage portal. The knob on the one-way valve and the lever on the ball valve was also shut off. The cylinder assembly was then detached from all the methane tank, one-way valve and reinforced pipe assembly. The pressure gage on the ball valve was also taken off. Then the cylinder assembly was put in the refrigerator for a period of 24 hours. After 24 hours, the cylinder assembly was taken out, observations were recorded, analysis was made, and results were reported. This procedure was repeated four times for this project. It is recommended that instead of introducing the samples to the cylinders through holes, there should be a remote supply and cut-off mechanism that could be manipulated without risking the evaporation of the sample or the production of a spark. It is recommended that this mechanism should be such that it allows the introduction of the sample into the cylinder after methane is allowed to fill in. Alternatively, a mechanism should be devised that would take all the air out of the cylinder before the entry of methane, thus eliminating the need for keeping hole “B” open for a longer duration of time so that the air trapped inside could be flushed out. Another recommendation is putting a steel box around the cylinder, shielding the highpressure equipment and thus introducing a safeguard against any accident. As mentioned before, the nonconformance of these observations with the proposed theory of these experiments did not suggest problems with the theory; rather they suggested major problems with the execution process of the experiments. This theory could bring about revolutionary changes in natural gas transportation industry. It could eliminate the need for using the lethal and hazardous chemicals that are being used by the same industry these days. Natural Gas is considered as the future energy source and the transportation of the same from the producing site to the consumer market is of great significance and importance. In the absence of smart environment-friendly and nature-compatible solutions, the industry seems to be intent on using these chemicals in the foreseeable future, and thus there is a need for conscious efforts for solving this crisis. This theory and the ensuing experiments are the right steps in the right direction.

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9.6.3 Solar irradiation for hydrate In this section, a sustainable method is proposed for keeping pipeline heated up. Khan and Islam (2012) identified a number of applications, such as refrigeration, heating, and cooling, for which the parabolic solar collector can be utilized to meet the energy requirement without resorting to very high-temperature outputs. For these applications, medium-range temperatures are sufficient. Between the above two temperature extremes, a variety of heattransfer fluids are also available, such as synthetic organic fluids and mineral oils. Synthetic organic fluids have aromatic ring structures and include the diphenyl
diphenyl oxide mixtures, biphenyls, terphenyls, and alkylated aromatics (Sahasranaman, 2005). Synthetic organic fluids are found suitable for a wide range of temperatures (260 C to 400 C). However, synthetic organic fluids are considered to be very expensive, as compared to other HTFs. In addition, Sahasranaman (2005) reported that some synthetic fluids are hazardous due to the degradative by-products that require special precautions. Some synthetic fluids and their vapors may cause skin and eye irritation after prolonged exposure, and emit pungent odors. Oyekunle and Susu (2005) reported mineral oils as heat transfer oil to be used for heat transfer systems operating in the 150 C
315 C temperature range. Mineral oils are petroleumbased and are composed of paraffinic or naphthenic hydrocarbons. Special refinery processes produce mineral oils from crude oils. Various additives are blended into the base stocks to provide the required characteristics (Oyekunle and Omotosho, 2003). However, most of the additives are synthetic in nature and thus make the mineral oil more prone to environmental pollution. They cannot, however, be pumped at low temperatures due to the high pour point and increased viscosity (Oyekunle and Susu, 2005). Bertrand and Hoang (2003) have discouraged the use of mineral/synthetic oil in spite of their excellent technical and cost benefits until their environmental performance is properly evaluated. However, most of the above fluids are toxic for long-term users. In the frame of the sustainable development principles, it is necessary to establish a set of safe and nontoxic thermal oils for using in the solar collector. In this study, the use of vegetable oil has been used to find out the performance of that oil as a thermal fluid. Vegetable oils have already been considered to be potential industrial fluids as early as the 1900s, especially to be used as lubricants, capacitors, bushings, etc. However, the interest in using this type of oil decreased due to its shortcomings in industrial applications, such as, oxidation and thermal stability (Wan Nik et al., 2005). That is why, the use of vegetable oil in closed environment, such as, in the receiver of a solar trough can be sought. Mercurio et al. (Mercurio et al., 2004) speculated that vegetable-oil might be more biodegradable than mineral oil due to the absence of high molecular weight aromatics. In addition, vegetable oils offer substantial advantages in ease of handling, shipping, and disposal as compared to the other HTFs. To enhance the operability of any solar heat-dependent appliances in the absence of daylight, it is necessary to incorporate a thermal storage system. In this process, some thermal storage materials are utilized to store the solar energy during a period of sunshine. Solar thermal energy storage can be classified into three categories (Tiwari, 2002): 1. Sensible heat storage. 2. Latent heat storage.

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3. Chemical storage. Sensible heat storage systems use the heat capacity and the change in temperature of the materials during the process of charging and discharging. Vegetable oil can be utilized as a thermal storage material too. In this study, the field data are collected as average daily radiation. However, the solar irradiation data of Halifax, collected from Environment Canada, was listed as monthly average daily radiation. Collares-Pereira and Rabl (1979) established a ratio (rt) of hourly to daily total radiation, as a function of day length and hour of interest: rt 5

IðtÞ π cosω 2 cosωs 5 ða 1 bcosωÞ sinωs 2 ð2πωs =360Þcosωs Ho 24

(9.1)

The coefficients a and b are given by the following equations: a 5 0:409 1 0:5016sinðωs 2 60Þ

(9.2)

b 5 0:6609 2 0:4767sinðωs 2 60Þ

(9.3)

where Ho is the daily total irradiation, Io is the hourly total irradiation, ω is the hour angle in degrees for time of interest, and ωs is the sunset hour angle. The above equations can be used to convert the daily total radiation to hourly total radiation. The detail of the equations can be found elsewhere (Khan and Islam, 2012).

FIGURE 9.26

Experimental solar trough. Source: Redrawn from Khan and Islam (2012).

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2.25m

1.8 m

TV 2.18m 11.5cm

90cm 50cm 2.4 m

1.9m

FV FIGURE 9.27

RHSV

The Top view (TV), Front view (FV), and Right-hand side view (RHSV) of a parabolic solar

contractor.

FIGURE 9.28 Construction solar collector assembly at Tuft Cove, Dartmouth, Canada.

Receiver Solar surface 9.6.3.1 Experimental setup and procedures In this study, a parabolic solar collector was constructed. Figs. 9.26 and 9.27 show a threedimensional (3D) view of a solar collector assembly and the projection of 3D view, respectively.

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Fig. 9.28 shows the constructed, experimental parabolic solar collector assembly with the above-mentioned dimensions, which was set up at Tuft Cove, Dartmouth, Nova Scotia, and Canada. This assembly was constructed and supplied by Veridity Env. Tech., Halifax, Nova Scotia, Canada. The main parts of the constructed solar collector assembly are as follows: (1) a parabolic solar surface and (2) a receiver. The parabolic trough consists of a parabolic surface made up of copper with a nickel plating on it placed on a wooden frame and a supporting mechanism on which the trough can be moved horizontally or vertically. The surface has a reflecting area of 4.05 m2 (2.25 3 1.8 m). The receiver of the solar collector consists of a copper tube bonded with a triangular sheet of thermally conductive material (fin). This structure is covered with transparent pyrex to reduce the conduction and convection heat loss from the receiver. Fig. 9.29 shows an assembly of the receiver. The carrier of the thermal fluid has the same configuration as the solar absorbing tube (copper tube). However, the portion exposed to the environment was well insulated with Teflon. 9.6.3.2 Solar pump and photovoltaic solar panel In this experiment a solar pump (Fig. 9.6) was used that was powered by a photovoltaic (PV) module (Fig. 9.7). The solar pump (model number: P24070) and the PV panels were supplied by Thermo Dynamics Ltd., Dartmouth, NS, Canada (Figs. 9.30 and 9.31).

FIGURE 9.29 Solar receiver in the focal line of parabolic solar

Fin

surface.

Copper Pyrex tube tube

Receiver

FIGURE 9.30

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FIGURE 9.31 Solar PV module.

TABLE 9.5 Physical properties of Unused Canola Oil [19]. Parameter

Value

Relative density (kg/m3, 20 C/water at 20 C) 

914
917

2

Viscosity (Kinematic at 20 C, mm /sec)

78.2



Smoke Point ( C)

220
230 

Flash Point, Open cup ( C)

275
290



Specific Heat (kj/kg at 20 C)

1.910
1.916 

Thermal Conductivity (W/m K)

0.179
0.188

9.6.3.3 Solar heat transfer fluid (thermal fluid) In this study, Canola vegetable oil and waste vegetable oil have been used as solar heat transfer fluid. Canola was supplied by Atlantic superstore, NS, Canada as food-grade vegetable oil. Waste vegetable was supplied by Soho Kitchen, Halifax, NS, Canada. Table 9.5 represents the physical properties of unused Canola oil. Thermal fluid storage. In this experiment, the thermal fluid was drawn from a tank made up of mild steel (14 ga steel). Thermometer. A high-temperature infrared thermometer was used to read the temperature of the fluid. It was REED ST-883 with a measuring temperature range from 250 C to 700 C. 9.6.3.4 Experimental procedure The experiments were carried out with two different modes: (A) once-through process and (B) circulation process. In the once-through process, the vegetable oil was circulated from a thermal storage tank and collected in different tanks. The inlet temperature and the outlet temperature of the vegetable oil were recorded when it was passing the copper tube of the receiver. In the recirculation process, five liters of vegetable oil were circulated from the same tank until its temperature reached 100 C. The temperature rise was recorded at regular intervals of time.

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9.6.3.5 Results and discussion Once-through process is characterized by almost stable inlet and outlet fluid temperatures of solar collector. Most of the energy transfer data were collected using once-through process. On the other hand, the recirculation process is characterized by continuously increasing inlet and outlet fluid temperatures due to the continuous circulation of fixed amount of fluid. That is why, in this process, the fluid temperature can reach a very high level. The continuous rise of fluid temperature can also be found when the fluid flows through a number of solar collectors, connected in series. The recirculation process is particularly preferred, when heat transfer at higher temperatures is required. In this study, most experimental data were collected in the month of September. The average temperature of the month of September in Halifax citadel is 15 C, recorded by the Canadian weather office [20]. However, experiments were carried out during midnoon and that is why the atmospheric temperature was more than average. Table 9.6 lists the fluid characteristics and recorded temperature of the fluid both for unused canola oil and waste vegetable oil. Data obtained from Table 9.6 were used to calculate the heat transfer rate from solar irradiation. Useful energy absorbed by the collector can be calculated from the fluid flow rate through the absorber, specific heat of the fluid, and inlet and outlet fluid temperatures. The instantaneous efficiency (ni) of the collector is given by the following equation: :

:

Qf ni 5 Ac IðtÞ

(9.4)

where Qf is the energy absorbed by the fluid in the receiver, Ac is the collector area, and I (t) is the incident radiation on the collector. Khan and Islam (2012) calculated the hourly average solar irradiation I(t) of Halifax for the month of September by using Eq. (9.1) which is 1733 kj/m2. This value was used in this experiment as hourly solar irradiation on the solar trough because the experiments were carried out in the consecutive days in the month of September and nearly at midnoon. Because of using this constant value of solar irradiation, a little error is expected in the calculation of efficiency. The efficiency of solar parabolic solar unit was calculated from the hourly solar energy absorption by the fluid and the hourly solar radiation, using Eq. (9.4). It has been stated in the experimental section that the total collector area is 4.05 m2. The performance of the solar collector with different oils is presented in Table 9.7. TABLE 9.6 Fluid characteristics and recorded temperature of the fluid in different months. Properties

Unused vegetable oil (Canola)

Waste vegetable oil

Inlet temperature



22 C

22 C

Outlet temperature (avg.)

67 C

56 C

Average velocity of oil in the receiver

19.3 mL/s

12.9 mL/s

3

Density of vegetable oil

916 kg/m

967 kg/m3

Specific heat capacity of vegetable oil

1.915 kj/kg-K

1.8 kj/kg-K (assumed)

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TABLE 9.7 Experimental data for once-through process.

Hourly solar energy absorbed by the fluid

Unused Canola oil

Waste vegetable oil

5459.86 kj

2643.179 kj 2

Hourly solar irradiation on the Collector

1733 kj/m

1733 kj/m2

Hourly solar irradiation on the total experimental collector

7018 kj

7018 kj

Efficiency of the collector

77.8%

37.67%

FIGURE 9.32 Temperature profile for absorber with clean canola oil and waste vegetable oil.

From the above table, it is found that the collector efficiencies with unused (clean) vegetable and with waste vegetable oil are 77.8% and 37.67%, respectively. Only the data of horizontal solar radiation was found in the literature. However, a parabolic solar surface is a tilted surface, which can receive solar beam normally. As a result, the actual solar radiation on to the parabolic surface is more than the reported solar radiation. This error might result in an increase of solar absorption efficiency by the solar collector understudy. In the second set of data, 5 L of clean canola oil and the same amount of waste vegetable oil were circulated in the same receiver from the same oil reservoir using a solar pump. The experiments were carried out until the temperature of the fluid reached 100 C. The solar pump that was used in these experiments had a maximum temperature limit of 100 C and that is why, the experiments were restricted to a temperature of 100 C. Fig. 9.32 shows the performance of the collectors for both oils under investigation. It is found that the collector with unused vegetable oil as thermal oil took only 32 minutes to reach 100 C whereas the collector with waste vegetable oil as thermal oil took 90 minutes to reach the same temperature. This shows the difference in the heat transfer rate between the two fluids. The higher heat transfer rate of unused vegetable oil is due to its higher heat transfer coefficient. Initially, big jump of the temperature was observed. This was followed by a nearly steady increase in temperature for a few minutes (Fig. 9.32). In fact, initially, the fluid experiences a high-temperature gradient when it passes through the solar receiver and that is why a jump of temperature is noticed. The flow rate of the fluid initially was 19.3 and 12.9 mL/s for unused and waste vegetable oil in the collector, respectively. For the first few minutes, the receiver drew very little

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hot fluid in the receiver, leading to minimal change in temperature during the initial period. However, the scenario changed very quickly as the total fluid in the oil storage became hot. Initially, the slow temperature increase was due to the low flow rate of oil due to high density and viscosity of the vegetable oil. However, once the oil was heated, the density and viscosity decreased and energy uptake was increased. The temperature and the solar irradiation fluctuated due to the change of other factors, such as temperature change, humidity change, and cloudiness, throughout the duration of the experiment. As the tracking of the sun was conducted manually, some experimental errors in the capture of solar radiation in the receiver were expected. A solar pump was used to circulate the fluid. However, the cloudiness sometimes affected the PV panel of the solar pump and the flow rate of the oil and thus influenced the energy intake by the oil. These would explain the fluctuations of absorbed solar radiation observed in the experimental data. Considering the trend of the temperature profile as depicted in Fig. 9.32, it can be speculated that the temperature would continue to increase if the oil circulation had continued. The average flash point of unused Canola oil is 283 C (Table 9.7). However, this flash point is only for open cup method and would not be the same for the closed system. Considering the flash point and the close environment, it can be speculated that the unused Canola oil can be used up to a temperature of 320 C. These results of a series of experiments performed using vegetable oils as thermal fluid, as used in a solar collector. The solar collector was placed in a place that is known for low solar radiation over the year. The experimental results show that vegetable oil can be an effective and environment-friendly alternative to synthetic or mineral oil. High viscosity is considered to be a problem for vegetable oil due to its high pumping cost. However, in this study, it was found that the fluid velocity increased from 19.3 to 30 mL/s for unused Canola oil and 12.9 to 18.6 mL/s for waste vegetable oil due to the increase in fluid temperature after absorbing solar energy. The temperature rise decreases the viscosity and the density of the fluids and thus increases the effectiveness of using the vegetable oil as a thermal fluid. The performance of waste vegetable was not as high as unused vegetable. It took a long time to reach a temperature nearly of 100 C as compared to the unused vegetable for the same type of receiver. So, it can be concluded that the unused vegetable oil can be used for low solar irradiation. However, for high solar irradiation, waste vegetable oil can provide satisfactory results. The use of waste vegetable oil can significantly decrease the cost of energy transfer oil, in addition to mitigating environmental problems, as related to the disposal of the waste vegetable oil.

9.7 Emerging technologies 9.7.1 Nonchemical approach Gas hydrates, particularly natural gas hydrates, for example, methane hydrates, may be formed and controlled within conduits and vessels by imparting energy to gas and water, for instance using agitation or vibration. The systems and methods allow for improved flow characteristics for fluids containing the gases, for example, hydrocarbon fluids being transported, and for improved overall efficiencies. The gas and water within a gas flow

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path may be perturbed or agitated to initiate the formation of relatively small hydrate particles. The hydrate particles continue to form as long as energy is imparted and water and hydrate guest molecules are available. High amplitude agitation of the gas and water will repeatedly break up agglomerated hydrate particles that form and encourage the formation of more and smaller particles. As more hydrate forms in this manner, less and less free water may be available proximate the gas and water contact. Some arrangements are known to try to clean hydrates or other matter from wellbores using acoustic energy. The vibratory transducers used in these earlier approaches are typically operated at high vibration frequencies, in one nonlimiting understanding. These highfrequency vibrations are used to shatter the matrix of an already formed hydrate plug or to remove an existing deposit of hydrates or other matter. It is believed, however, that these higher frequencies are not effective in preventing the initial deposition of hydrates and other deposits within portions of a wellbore or pipeline. Thus these prior approaches have not been effective in preventing the initial agglomeration and buildup of hydrates within the conduit. Other systems and methods for inhibiting the deposition of natural gas hydrates involve use of high-amplitude vibration. The gas and water within a gas flow path may be perturbed or agitated to initiate the formation of relatively small hydrate particles. The hydrate particles continue to form as long as energy is imparted and water and hydrate guest molecules are available. High amplitude agitation of the gas and water will repeatedly break up agglomerated hydrate particles that form and encourage the formation of more and smaller particles. As more hydrate forms in this manner, less and less free water may be available to proximate the gas and water contact (O’Malley et al., 2006). These techniques focus on inhibiting the formation and growth of a hydrate matrix that would allow a solid plug or blockage to develop within a flowbore. In described embodiments, an acoustic inhibitor may be associated with a wellbore proximate the wellhead and may be used to generate a low-frequency acoustic energy signal that is propagated axially through the wellbore. The wellbore was used as a waveguide to propagate the energy signal. In one nonlimiting embodiment, the acoustic waves are generated at a frequency in a relatively low-frequency range that may be generally from about 1000 Hz to about 2200 Hz. Particularly effective frequencies for inhibiting the growth and formation of a hydrate matrix are 1130 and 2000 Hz. In accordance with the systems and methods described herein, the gas/water interface (a hydrocarbon/water interface, in one nonlimiting embodiment) within a conduit or vessel may be agitated or perturbed to initiate the formation of small hydrate particles. The hydrate particles may continue to form as long as agitation is sustained and water and any hydrate guest molecules are available. High amplitude agitation of the gas and water may repeatedly breakup the hydrate particles that form and encourage the formation of more and smaller particles. The increased number of particles may provide an increased seed surface area upon which more hydrates can form, although the inventors do not wish to be limited to any particular theory or explanation. This conversion increases the efficiency of free water removal from the fluid being transported and may allow the resulting hydrate particles to more freely flow through the conduit along with the produced gas or hydrocarbon fluid without being deposited onto pipeline walls, valves, and other equipment. Thus, the hazards associated with hydrates may be significantly reduced or eliminated. The following major claims are made in this patent:

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1. A method for controlling the agglomeration of gas hydrates within a vessel or flowbore comprising: a. providing gas and water in a vessel or a flowbore; b. imparting relative energy to at least a portion of the gas and water to promote formation of nonagglomerating hydrate particles having an average particle size of about 0.175 inch (about 4.4 mm) in diameter or smaller. 2. The method of claim 1 where imparting relative energy comprises vibrating the portion of the gas and water by an acoustic vibrator located proximate to the gas/water interface. 3. A system for controlling gas hydrates within a vessel or flowbore, the system comprising: a. at least one vessel or flowbore containing gas and water; and at least one energizer to impart relative energy to at least one portion of the gas and water to promote formation of nongglomerating hydrate particles having an average particle size of about 0.175 inch (about 4.4 mm) in diameter or smaller. 4. The system of claim 3 where the energizer is attached to the vessel or flowbore. 5. The system of claim 3 where the energizer is an acoustic vibrator. 6. A method for controlling the agglomeration of gas hydrates within a vessel or flowbore comprising: a. providing gas and water in a vessel or a flowbore; b. imparting relative energy at least a portion of the gas and water to promote formation of hydrate particles from the gas and water within the vessel or flowbore; and c. forming nonagglomerating gas hydrate particles having an average particle size of 6400 microns or less. 7. The method of claim 6 where the nonagglomerating gas hydrate particles have an average particle size of about 4400 microns or less, and further imparting relative energy to gas hydrate particles to reduce their average particle size from about 6400 microns or greater to an average particle size of about 4400 microns or less. 8. The method of claim 6 where the hydrate particles have an average particle size of about 200 microns in diameter or smaller. 9. The method of claim 6 further comprising introducing a chemical additive that further controls hydrate particle formation. 10. The method of claim 6 where the gas hydrates are natural gas hydrates. 11. The method of claim 6 further comprises introducing gas molecules to the portion of gas and water at a temperature and pressure that forms hydrate particles. 12. A system for controlling gas hydrates within a vessel or flowbore, the system comprising: a. at least one vessel or flowbore containing gas and water; b. at least one energizer to impart relative energy to at least one portion of the gas and water to promote formation of nonagglomerating hydrate particles, where the hydrate particles have an average particle size of about 0.25 inch (about 6.4 mm) in diameter or smaller; c. at least one sensor to detect conditions favorable to hydrate formation, where the sensor is connected to a control network to activate the energizer; and d. an opening for introducing gas molecules to the gas and water to form hydrate particles at a temperature and a pressure for forming hydrates.

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13. The system of claim 12 where the energizer is an acoustic vibrator. 14. The system of claim 12 where further comprising an opening for introducing a chemical additive to the gas/water interface. 15. A method for controlling the agglomeration of gas hydrates within a vessel or flowbore comprising: a. providing gas and water in a vessel or a flowbore; b. imparting relative energy to at least a portion of the gas and water to promote formation of nonagglomerating hydrate particles, where the hydrate particles have an average particle size of about 0.25 inch (about 6.4 mm) in diameter or smaller. 16. The method of claim 15 where imparting relative energy comprises energizing the portion of the gas and water at a frequency within the range of from about 1 kHz to about 20 kHz. 17. The method of claim 15 where imparting relative energy comprises vibrating the portion of the gas and water by a vibratory source that provides a vibrational amplitude in the range of from about 1 nm to about 1 cm. 18. The method of claim 15 further comprising imparting relative energy to gas hydrate particles to reduce their average particle size from about 6400 microns or greater to an average particle size of about 4400 microns or less. 19. The method of claim 15 where the hydrate particles have an average particle size of about 200 microns in diameter or smaller. 20. The method of claim 15 further comprising introducing a chemical additive that further controls hydrate particle formation. 21. The method of claim 15 where the imparting relative energy comprises mixing. 22. The method of claim 21 where the mixing comprises rotational mixing. 23. The method of claim 15 further comprising flowing the gas and water in a flowbore. 24. The method of claim 15 further comprising storing the gas and water in a vessel. 25. The method of claim 15 where the gas hydrates are natural gas hydrates. 26. The method of claim 15 further comprising introducing gas molecules to the portion of gas and water at a temperature and pressure that forms hydrate particles. 27. The method of claim 15 where imparting relative energy comprises vibrating the portion of the gas and water by an acoustic vibrator located proximate the gas/water interface. 28. A system for controlling gas hydrates within a vessel or flowbore, the system comprising: a. at least one vessel or flowbore containing gas and water; and b. at least one energizer to impart relative energy to at least one portion of the gas and water to promote formation of nonagglomerating hydrate particles, where the hydrate particles have an average particle size of about 0.25 inch (about 6.4 mm) in diameter or smaller. 29. The system of claim 28 where the energizer comprises a rotational stirrer. 30. The system of claim 28 further comprising an opening for introducing gas molecules to the gas and water to form hydrate particles at a temperature and a pressure for forming hydrates. 31. The system of claim 28 where the energizer is attached to the vessel or flowbore. 32. The system of claim 28 where the energizer is an acoustic vibrator.

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33. The system of claim 32 where the acoustic vibrator is capable of operation at a frequency in the range from about 1 kHz to about 20 kHz. 34. The system of claim 32 where the acoustic vibrator is operated at an amplitude in the range of about 1 nm to about 1 cm. 35. The system of claim 32 where the acoustic vibrator comprises a device selected from the group consisting of a horn, a piezoelectric transducer, a fluid oscillator, a voice coil actuator, a rotating eccentric mass, and combinations thereof. 36. The system of claim 32 where further comprising an opening for introducing a chemical additive to the gas/water interface.

9.7.2 Chemical approach The most basic solution used in this approach is methanol. The addition of methanol shifts the thermodynamic limit of gas hydrate formation to lower temperatures (thermodynamic inhibition). However, the addition of methanol gives rise to greater safety problems (flash point and toxicity of the alcohols), logistic problems (greater storage tanks, recycling of these solvents) and accordingly high costs, especially in offshore production. Accordingly, a need exists for alternative additives to methanol, which either dissolve gas hydrates or inhibit gas hydrate formation in pipelines. The alternative additives described in the patent of Sayed and Saini (2021) disclosure at least partially dissolve gas hydrates, prevent the nucleation and/or the growth of gas hydrates, or modify the gas hydrate growth in such a way that smaller hydrate particles result. The gas hydrate dissolving solution generates heat that is used to dissolve the gas hydrate. Including a strong acid in the solution allows the solution to generate heat quickly and therefore accelerate reaction completion. Including an organic acid in the solution allows the solution to generate heat at a slower rate as compared to using strong acids. Therefore including organic acids in the solution allows placement of the gas hydrate dissolving solution prior to generating heat prematurely. The method includes introducing a gas hydrate dissolving solution into the pipeline, the gas hydrate dissolving solution comprising sodium nitrite, ammonium chloride, a strong acid, and a weak organic acid; and allowing the gas hydrate dissolving solution to at least partially dissolve the gas hydrate in the pipeline, where the strong acid expedites the reaction. This solution generates the heat that is used to dissolve the gas hydrate. Methods of dissolving may include introducing encapsulated sodium nitrite, encapsulated ammonium chloride, an encapsulated strong acid, and an encapsulated weak organic acid into the pipeline. In embodiments, gas hydrates may form in pipelines where hydrocarbon fluid is flowing. Specifically, in embodiments, hydrocarbon fluid may be flowing through the pipeline when introducing the gas hydrate dissolving solution. The hydrocarbon fluid may include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, carbon dioxide, hydrogen sulfide, dinitrogen, crude oil, fresh water, formation brine, or combinations of these. The principal claims are: 1. A method of dissolving a gas hydrate in a pipeline comprising:

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9.7 Emerging technologies

2. 3.

4.

5.

6. 7. 8.

9. 10. 11.

12. 13. 14.

703

a. introducing a gas hydrate dissolving solution into the pipeline, the gas hydrate dissolving solution comprising sodium nitrite, ammonium chloride, a strong acid, and a weak organic acid; and b. allowing the gas hydrate dissolving solution to at least partially dissolve the gas hydrate in the pipeline, where the strong acid expedites the reaction. The method of claim 1, in which the strong acid comprises hydrochloric acid and the weak organic acid comprises acetic acid. The method of claim 2, in which the hydrochloric acid is an aqueous solution comprising from 10 to 50 wt.% of concentrated hydrochloric acid and the acetic acid comprises glacial acetic acid with a concentration from 95 to 99.9 wt.%. The method of claim 1, in which introducing the gas hydrate dissolving solution comprises introducing from 1 to 60 vol. % gas hydrate dissolving solution, based on a total volume of water in the pipeline. The method of claim 1, in which the gas hydrate dissolving solution comprises: a. from 5 to 30 vol. % sodium nitrite solution, based on a total volume of water in the pipeline; b. from 5 to 30 vol. % ammonium chloride solution, based on the total volume of water in the pipeline; c. from 0.2 to 2 vol. % strong acid, based on the total volume of water in the pipeline; and d. from 0.5 to 5 vol. % weak organic acid, based on the total volume of water in the pipeline. The method of claim 5, in which the sodium nitrite solution comprises from 0.5 to 10 moles of sodium nitrite. The method of claim 5, in which the ammonium chloride solution comprises from 0.5 to 10 moles ammonium chloride. The method of claim 1, in which the gas hydrate dissolving solution comprises: a. from 20 to 30 vol. % sodium nitrite, based on a total volume of water in the pipeline; b. from 20 to 30 vol. % ammonium chloride, based on the total volume of water in the pipeline; c. from 0.5 to 1 vol. % strong acid, based on the total volume of water in the pipeline; and d. from 1 to 3 vol. % weak organic acid, based on the total volume of water in the pipeline. The method of claim 8, in which the strong acid comprises from 10 to 20 wt.% hydrochloric acid and the weak organic acid comprises from 5 to 15 wt.% acetic acid. The method of claim 1, in which allowing the gas hydrate dissolving solution to at least partially dissolve the gas hydrate takes less than 6 hours. The method of claim 1, in which the gas hydrate dissolving solution comprises an aqueous solution comprising the sodium nitrite, ammonium chloride, strong acid, and weak organic acid. The method of claim 1, further comprising inhibiting gas hydrate formation in the pipeline after introducing the gas hydrate dissolving solution. The method of claim 1, in which a pressure of the pipeline is greater than 500 psi and a temperature of the pipeline is less than 100 F. The method of claim 1, in which the gas hydrate comprises free water, carbon dioxide, hydrogen sulfide, methane, ethane, propane, n-butane, iso-butane or combinations thereof.

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15. The method of claim 1, further comprising allowing hydrocarbon fluid to flow through the pipeline during introducing the gas hydrate dissolving solution, where the hydrocarbon fluid comprises methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, crude oil, carbon dioxide, hydrogen sulfide, dinitrogen, or combinations of these. 16. The method of claim 1, further comprising allowing the dissolved gas hydrate to discharge from the pipeline after allowing the gas hydrate dissolving solution to at least partially dissolve the gas hydrate in the pipeline. 17. The method of claim 1, in which introducing a gas hydrate dissolving solution into the pipeline comprises introducing the gas hydrate dissolving solution at an injection rate of from 0.5 to 20 gal/min. 18. The method of claim 1, in which the gas hydrate dissolving solution further comprises a corrosion inhibitor, a scale inhibitor, a demulsifier, or combinations thereof. 19. The method of claim 1, in which the gas hydrate dissolving solution further comprises glycol, a glycol ether, dimethylformamide, cesium formate, potassium formate, or combinations thereof. 20. The method of claim 1, further comprising heating the gas hydrate dissolving solution prior to introducing the gas hydrate dissolving solution into the pipeline. 21. The method of claim 1, in which the gas hydrate dissolving solution raises the temperature inside the pipeline after mixing to 20 C
120 C. 22. The method of claim 1, in which the gas hydrate dissolution solution further comprises gas hydrate inhibitors.

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C H A P T E R

10 Corrosion and its mitigation 10.1 Introduction In 1946 the American Electrochemical Society defined corrosion as the “destruction of a metal by chemical or electrochemical reaction with its environment.” The destruction of metals by corrosion occurs as follows (Chilingar et al., 2009): 1. direct chemical attack at elevated temperatures in a dry environment; and 2. by electrochemical processes at lower temperatures in a water-wet or moist environment. Corrosion occurs because metals tend to revert to more stable forms in which they were found in nature initially, that is, oxides, sulfates, sulfides, or carbonates. A little-known fact is that corrosion is inherent to artificially processed metal. Artificial processing renders the final product (metal) harbor an unstable state. As such, it is prone to oxidation and other reactions due to natural tendency to revert to its natural state. This topic has been addressed in the past, although never in the context of corrosion. In this context, iron is an interesting example. While iron is the most abundant mineral on earth, it is mainly concentrated in the inner core. In the earth’s crust, iron is only 5%, coming after aluminum and silicon. In the earth’s crust, iron never occurs in elemental form and iron oxide minerals, such as hematite (Fe2O3), magnetite (Fe3O4), and siderite (FeCO3), are the major ores of iron. Many igneous rocks also contain the sulfide minerals pyrrhotite and pentlandite Pyrrhotite and pentlandite are the most common Fe sulfide minerals in magmatic ore deposits and meteorites. Multiple S isotopes pairing with Fe isotopes of bulk Fe sulfides have proven to be useful tracers to constrain the formation and evolution of magmatic ore deposits. However, pyrrhotite coexists with pentlandite and other sulfides as intergrowth textures in most cases. In summary, pyrrhotite and pentlandite reference materials are suitable for in situ S and Fe isotope microanalysis and are expected to be used for tracking the formation processes of Fe sulfide minerals in magmatic ore deposits and meteorites soon (Chen et al., 2021). On the other hand, ferropericlase (Mg,Fe)O, a solid solution of periclase (MgO) and wu¨stite (FeO), makes up about 20% of the volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO3; it is also the major host for iron in the lower mantle. The determination of the chemical composition of Earth’s lower mantle is a long-standing

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challenge in earth science. Accurate knowledge of sound velocities in the lower-mantle minerals under relevant high-pressure, high-temperature conditions is essential in constraining the mineralogy and chemical composition using seismological observations, but previous acoustic measurements were limited to a range of low pressures and temperatures. Murakami et al. (2012) determined the shear-wave velocities for silicate perovskite and ferropericlase under the pressure and temperature conditions of the deep lower mantle using Brillouin scattering spectroscopy. The mineralogical model that provides the best fit to a global seismic velocity profile1 indicates that perovskite constitutes more than 93% by volume of the lower mantle, which is a much higher proportion than that predicted by the conventional peridotite mantle model. It suggests that the lower mantle is enriched in silicon relative to the upper mantle, which is consistent with the chondritic Earth model. Such chemical stratification implies layered-mantle convection with limited mass transport between the upper and the lower mantle. At the bottom of the transition zone of the mantle, the reaction γ-(Mg,Fe)2[SiO4] 2 (Mg,Fe)[SiO3] 1 (Mg,Fe)O transforms γ-olivine into a mixture of silicate perovskite and ferropericlase and vice versa. Silicate perovskite may form up to 93% of the lower mantle, and the magnesium iron form, (Mg,Fe)SiO3, is considered to be the most abundant mineral on the Earth, making up 38% of its volume. These natural occurrences of iron give us a clue as to how to develop sustainable pipeline materials in the future. With the current development model, the focus has been to develop more artificial materials. One of the major concerns in the oil and gas industry is corrosion. National Association of Corrosion Engineers reports indicate that the total annual estimated direct cost of corrosion in the United States alone is a staggering approximately 3% of the nation’s gross domestic product (GDP). Although corrosion management has improved over the past several decades, the United States must find more and better ways to encourage, support, and implement optimal corrosion control practices. Corrosion is a naturally occurring phenomenon commonly defined as the deterioration of a substance (usually a metal) or its properties because of a reaction with its environment. Like other natural hazards such as earthquakes or severe weather disturbances, corrosion can cause dangerous and expensive damage to everything from automobiles, home appliances, and drinking water systems to pipelines, bridges, and public buildings. According to a US corrosion study, the direct cost of metallic corrosion is $276 billion on an annual basis. This represents 3.1% of the US GDP in 1998. Corrosion is so prevalent and takes so many forms that its occurrence and associated costs cannot be eliminated completely. However, it has been estimated that 25% to 30% of annual corrosion costs in the United States could be saved if optimum corrosion management practices were employed. Almost one-third of infrastructure damage caused by corrosion is in pipelines (Fig. 10.1). Corrosion is the primary factor affecting the longevity and reliability of pipelines that transport crucial energy sources throughout the nation. There are more than 528,000 km (328,000 miles) of natural gas transmission and gathering pipelines, 119,000 km (74,000 miles) of crude transmission and gathering pipelines, and 132,000 km (82,000 miles) of hazardous liquid transmission pipelines. The average annual corrosion-related cost is estimated at $7 billion to monitor, replace, and maintain these assets. The corrosionrelated cost of operation and maintenance makes up 80% of this cost.

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FIGURE 10.1 Infrastructure damage caused by corrosion.

Corrosive agents may be classified into two general categories: 1. those present in feedstock or crude oil/gas; and 2. those associated with processes or control. Water is usually present in crude oils, and complete removal is difficult. Water acts as an electrolyte and causes corrosion. It also tends to hydrolyze other materials, particularly chlorides, and thus forms an acidic environment. Carbon dioxide is recognized as one of the most important corrosive agents, especially in operations where gas is the feedstock or raw material. Many gas wells produce large quantities of carbon dioxide. Saltwater is produced in most oil wells, and relatively large quantities of it get into the refinery, either in the water emulsified in the crude or in the crystalline form dispersed in the crude. The salts are calcium chloride, magnesium chloride, and sodium chloride. Desalting methods include washing and settling, and the addition of chemicals such as sulfonates to break the emulsion, centrifuging, and filtering. Salts and water are usually removed as quickly as possible, but the operations are often incomplete. If they are not removed, or only partially removed, hydrochloric acid often forms. Magnesium chloride is readily hydrolyzed. In this case, ammonia may be needed in amounts equivalent to three times the stoichiometric equivalent of sulfide and chloride ions. Hydrogen sulfides, mercaptans, and other sulfur compounds are present in many of the crudes and gases processed by refineries. These are removed by reaction with sodium hydroxide, lime, iron oxide, or sodium carbonate, but for various reasons, they are frequently not removed until the final operation is approached. Corrosion problems are associated with the refining process itself or with processes utilized to remove sulfur compounds. Nitrogen is becoming an important consideration in some of the newer processes. Nitrogen is present in some crudes, but a more important source is the nitrogen in the air. Large quantities of air are used in some of the burning

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operations associated with catalytic cracking processes. Ammonia and cyanides will form under certain conditions when nitrogen is present. The former can damage heat exchangers made of copper-bearing alloys. Cyanides are an important factor controlling the diffusion of hydrogen into steel. Oxygen (or air) is drawn into tanks and other equipment as they are emptied, or entered during shutdown periods. It could also be drawn into the system by pumps. Oxygen can also be present as a result of reactions of other compounds, such as water and carbon dioxide. The water used in the system often contains oxygen in solution. Sulfuric acid is used in large quantities in many refinery operations such as alkylation and polymerization. The acid becomes contaminated and its corrosion characteristics may change. Utilization of this acid and its recovery or concentration presents corrosion problems that are extremely important to the refinery. For example, sludges often contain large quantities of carbon or carbonaceous material which make the acid strongly reducing in nature. These may attack stainless steels, and under the same conditions, the copper-base alloys will give better performance. In addition to the “naturally occurring” carbon dioxide, some severe problems have been encountered because of CO2 injection or flooding to enhance recovery of oil. Two basic components of the mechanism are consistent with actual experiment: (1) the main cathodic reaction is the reduction of undissociated carbonic acid or hydrogen ion; (2) the expected high corrosion rates from the latter reaction are not achieved in many systems because of the inhibiting effect of ferrous carbonate scale. Various inhibitors are used in petroleum industries in various stages. There are three types of pipeline systems through which gas is transported from the source to the end users: gathering, transmission, and distribution systems. Gathering and distribution pipelines represent the beginning and end of the gas pipeline system. NTSB staff analyzed 10 years (2004
13) of both annual report mileage and incident data for all pipelines. Although onshore gas transmission pipelines constitute only about 12% of all pipeline mileage in the United States,8 they represent 15% of total incident numbers, 16% of combined fatalities and injuries (10% of fatalities and 18% of injuries), and 20% of reported property damage.9 This indicates that although there were more fatalities and injuries associated with gas distribution incidents, and injuries in gas transmission incidents (per mile) were overrepresented. Additionally, reported nominal property damages resulting from gas transmission pipeline incidents between 2004 and 2013 also far exceeded those caused by gas distribution incidents. Compared to gas distribution pipelines, transmission pipelines typically have larger diameters and operating pressures. Therefore, the potential impact of a transmission pipeline incident on its surroundings is high. This study focuses on onshore transmission pipelines. From 1984 to 2013, onshore gas transmission pipeline mileage increased from approximately 280,000 to 300,000 miles, which represents approximately 750 miles of gas transmission pipelines added each year.10 Transmission pipelines are classified as either interstate or intrastate. Interstate pipelines are subject to federal oversight, and most states assume oversight for intrastate pipelines. Fig. 10.2 shows the onshore gas transmission pipeline system for year-end 2012 by operation types. A state must adopt the minimum federal regulations and also provide for enforcement sanctions substantially the same as those authorized by the federal pipeline safety regulations. Based on mileage, 64% of all gas transmission pipelines are interstate pipelines, while 36% are intrastate pipelines. The locations of these onshore gas transmission pipelines are not evenly distributed across the United States. Fig. 10.2 shows that more than half of all transmission pipelines

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FIGURE 10.2

Map of the United States gas transmission pipeline systems by operation type (interstate and intrastate, year-end 2012).

are located in 10 states, including Texas and Louisiana, which have the most transmission pipelines (15% and 9%, respectively). Texas has 71 operators with intrastate pipelines and Louisiana has 31. Of the lower 48 United States, those with the most natural gas pipeline running through them are Texas (58,588 miles), Louisiana (18,900 miles), Oklahoma (18,539 miles), Kansas (15,386 miles), Illinois (11,900 miles), and California (11,770 miles). Seventy-five percent of all gas transmission pipelines are located in 20 states (Fig. 10.3). Many gas pipeline companies with large multistate or nationwide systems operate both interstate pipelines (subject to federal regulation) and intrastate pipelines (usually subject to state regulation). For example, the 2013 Pipeline and Hazardous Materials Safety Administration (PHMSA) annual report 13 shows that 29 gas transmission pipeline operators operate both interstate and intrastate pipelines; 11 of these operators have intrastate pipelines in more than one state. There are 743 operators with intrastate pipelines only. Of these operators, 93 operate in more than one state, and one operator has intrastate pipelines in nine states. The remaining 121 operators only have interstate pipelines.14 Thirty percent of all intrastate pipelines are located in Texas, followed by California (11%) and Oklahoma (6%).

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FIGURE 10.3 Distribution of onshore gas transmission pipeline by state (based on 2013 NPMS data, year-end 2012). NPMS, National Pipeline Mapping System.

TABLE 10.1 Common corrosion types (Popoola, 2019). Corrosion type

Mechanism

Pitting

This is localized corrosion attack due to neutralization salt’s presence on metal surface causing some parts to corrode quickly (acting as anode) but some are free from corrosion (acting as cathode). Thereby, causing deep holes.

Galvanic

Flow of electrons between two dissimilar metals resulting from potential difference exists between them when subjected to corrosive media thereby causing corrosion. The less resistant metal acted as anode while the most resistant acted as cathode.

Uniform

Uniform occurrence of corrosion on all areas of metal at the same rate.

Crevice

Occurrence of corrosive liquid capture in between metal gaps resulted in concentration cell corrosion.

Erosion

Exposure of metal surface to a high-velocity corrosive fluid thereby, exposing the stripped surface to more corrosion attack.

Stress-corrosion cracking

Mechanical tensile stress and hostile chemical corrosive medium caused formation of fracture in metal structure thereby exposing the fractured surface or point to more corrosion attack.

Intergranular

Corrosion occurrence on metal grain boundaries.

Corrosion fatigue

Corrosion due to combined effects of cyclic stress and corrosive medium.

Fretting

Advanced erosion
corrosion due to metal fretting and corrosive medium combined effects.

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10.2 Background and historical context

FIGURE 10.4 Chemical reactions of

Overall Chemical Reacon Fe + 2H + oFe2+ + H2 Oxidaon Half Reacon

Fe oFe2+ + 2e – Neutral or Basic Condions w/ Oxygen Contaminaon

O2 +2H2O + 4e –oOH – Fe2+ + 2OH – oFe(OH)2,(s)

711

corrosion process.

Reducon Half Reacon

2H+ +2e – oH2

Carbon Dioxide “Sweet” Corrosion Fe + CO2+ H2O o FeCO3,(s) + H2

Hydrogen Sulfide “Sour” Corrosion

Fe +H2S oFeS(s) + H2

A summary of common corrosion types and their respective mechanisms have been presented in Table 10.1. The impact of corrosion costs caused by both direct and indirect damage of materials on the economic status of the world is becoming alarming. Research works conducted from 1999 to 2001 on corrosion costs and preventive strategies in both the United States and the United Kingdom revealed 3.1% of their GDP as costs spent only on direct corrosion damage. The economics of corrosion can be grouped into capital costs (equipment replacement, redundant equipment, and excess capacity), control costs (maintenance, repair, and corrosion control), design costs (materials of construction, special processing, and corrosion allowance), and associated costs (technical support, product loss, insurance, and equipment inventory). However, studies have shown that corrosion cost can be reduced by 15%
20% if low-cost novel corrosion control techniques are applied. Thus, there is need to develop novel techniques and methods to tackle this dangerous phenomenon from existing prominent ones which are protective coatings and linings, cathodic/anodic protection, and corrosion inhibitors. Table 10.1 gives a summary of ways of controlling corrosion. However, results of numerous researches conducted in anticorrosion materials applications in previously mentioned engineering fields revealed using corrosion inhibitors as the most effective and simple approach to preventing deleterious degradation of metals and alloys in corrosive media. Fig. 10.4 depicts summary of chemical reactions of corrosion process.

10.2 Background and historical context 10.2.1 Summary of mining and mineral processing Fig. 10.5 shows various processes involved in mining and mineral processing operations.

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FIGURE 10.5 Various stages of mining and mineral processing operation.

Raw ore

Crushing-Grinding

Gravity Separation/ Flotation

Refining

Leaching

At present, technologies involving crushing-grinding are considered “settled,” with only research activities in automatizing the process and application of rock particle characterization tools. At present, very expensive equipment such as scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) are used. These are the areas where US companies make the most profit. Gravity separation/floatation has active research topics, all focusing on developing artificial/synthetic additives that accelerate the process but become a driver of environmental toxicity. Time saved or achieving higher efficiency cannot justify the use of such chemicals, but few, if any consider alternative solutions, mostly focusing on developing more toxic chemicals. Leaching has been using synthetic acid and other chemicals, since the industrial revolution. Although researchers are discovering natural chemicals that were used by older civilizations, no active research exists on reviving those technologies. The refining process relies on both synthetic chemicals and fossil fuel/electric heating. Similar to what is discussed regarding leaching, all research activities currently focus on progressively more toxic chemicals, including nanomaterials or so-called smart fluids. The sustainability of these products is assured only through current sustainability criterion. Historically, such criterion has been found to be inherently defective and needed

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TABLE 10.2

List of chemicals used in refining metals.

Reagent

Toxicity

Advantages

Disadvantages

Cyanide

Very high

High dissolution rate

Environmental issues

Agua Regia

High

High dissolution rate

No feasible large-scale applications

Chlorination

Medium

Bromine and Iodine

Low

Proven technology; Good efficiency High dissolution rate

No feasible large-scale applications High temperatures required; High reagent costs

Thiocyanate

Medium

Recyclable

Thiosulfate

Medium

Cheap reagent

Thiourea

Medium

Bacteria

Low

Proven technology; High dissolution rate; and speed Reduction of reagent consumption; Higher leaching yield

No feasible Large-scale applications; Limited availability Detoxification costs; High reagent consumption Dissolution of heavy metals besides gold Slow reaction; Difficult process control

From Go¨kelma et al. (2018).

continuous adjustments as new evidence of environmental impact surfaced. Table 10.2 shows some of the chemicals used at present. Note that the ranking in toxicity is based on current standard, which does not include long-term impacts. Even then, none of the processes can be considered nontoxic. This is in sharp contrast with what used to be the practice in ancient civilizations, as we will see in the latter section. In terms of energy sources and their sustainability, the question of sustainability does not even arise in electric fossil fuel energy. This is a research topic that has tremendous potential and has only been alluded to in recent works of Islam (Islam, 2020; Khan and Islam, 2016; Islam et al., 2018).

10.2.2 The history of mining and mineral processing People have practiced mining and quarrying since ancient times. Past civilizations had a sustainable approach to materials. For instance, what is known as Afghanistan today had mining practices of gold, silver, copper, and gemstones dating back to 2000 BCE and earlier. Although not formally mentioned, gold and silver extraction is likely to precede copper or iron. The exact date that humans first began to mine gold is unknown and precedes the modern timeline of historical events. Evidence from around the world indicates that gold mining could be at least 7000 years old. Also, Bronze Age gold objects are plentiful. Mining was under the control of the state but the mines may have been leased to civilian contractors sometime later. The gold served as the primary medium of exchange within the empire and was an important motive in the Roman invasion of Britain by Claudius in the 1st century CE, although there is only one known Roman gold mine at Dolaucothi in west Wales. Gold was a prime motivation for the campaign in Dacia when the Romans invaded Transylvania in what is now modern Romania in the 2nd century CE. The legions were led by the emperor Trajan, and their exploits are shown on Trajan’s Column in Rome and the several reproductions of the column elsewhere (such as the

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Victoria and Albert Museum in London) [3]. Under the Eastern Roman Empire Emperor Justinian’s rule, gold was mined in the Balkans, Anatolia, Armenia, Egypt, and Nubia [4]. The Encyclopedia of History puts the following timeline for gold. 5000 BCE: Electrum (gold and silver alloy) was used by the Egyptians in jewelry. 3000 BCE: Sumer civilization in Mesopotamia used gold in jewelry manufacture. 2500 BCE: Egyptians invented the technique of filigree in the manufacture of gold objects. 1800 BCE: Minoans on Crete used gold in jewelry manufacture. 1550 BCE: Gold death masks (including that of “Agamemnon”) were made at Mycenae. 1200 BCE: Chavin civilization in Peru manufactured goods made of gold. 609 BCE to 560 BCE: Reign of Alyattes of Lydia. Minting of first coins made from electrum. 8. 560 BCE: Croesus of Lydia first manufactured coins of solid gold. 1. 2. 3. 4. 5. 6. 7.

Some researchers suggest that the technology of those days was famous, with evidence that even Pharaohs benefited from Afghan minerals and gemstones. Materials containing finely ground iron (III) oxides or oxide-hydroxides, such as ocher, have been used as yellow, red, and brown pigments since prehistorical times. They also contributed to the color of various rocks and clays, including entire geological formations like the Painted Hills in Oregon and the Buntsandstein. Similarly, “Jurassic sandstone” in Germany, Bath stone in the UK, etc. were routinely used. These are iron-rich stones that are in stable form. Significant amounts of iron occur in the iron sulfide mineral pyrite (FeS2), but it is difficult to extract iron from it and it is therefore not exploited. In fact, iron is so common that production generally focuses only on ores with very high quantities of it. Historically, much of the iron ore utilized by industrialized societies has been mined from predominantly hematite deposits with grades of around 70% Fe. These deposits are commonly referred to as “direct shipping ores” or “natural ores.” Ocher is a clay that is colored by varying amounts of hematite, varying between 20% and 70%. Red ocher contains unhydrated hematite, whereas yellow ocher contains hydrated hematite (Fe2O3 H2O). The principal use of ocher is for tinting with a permanent color. Curiously, the scientific literature is silent in noting corrosion inhibition before the industrial revolution, although metal was extensively used for numerous applications. One possible explanation is when metal is processed organically, that is, using earth material and wood or coal fire (without synthetic chemicals or artificial energy sources), the metallic product is stable and does not undergo oxidation reactions to produce corrosion effects. Today, it is known that iron production began in Anatolia in approximately 2000 BCE, and the Iron Age was well established by 1000 BCE. All through this period, the raw materials of iron were iron ore and charcoal. The iron was produced in small shaft furnaces as solid lumps, called blooms, and these were then hot forged into bars of wrought iron, a malleable material containing bits of slag and charcoal. Although it was not explicitly mentioned nor calculated, the carbon contents of the early irons ranged from very low (0.07%) to high (0.8%), the latter constituting genuine steel, in today’s standard. When the carbon content of steel is above 0.3%, the material will become very hard and brittle if it is quenched in water from a temperature of about 850 C to 900 C (1550 F to 1650 F). The brittleness can be decreased by reheating the steel within the range of 350 C
500 C



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(660 F
930 F), in a process known as tempering. This type of heat treatment was known to Asia minor civilizations even prior to 2000 BCE and the process was used for producing gold and silver. Microstructure studies of remaining artifacts reveal that Egyptians were using the technology to manufacture knives and swords as early as 900 BCE. Islam et al. (2010) put this timeline to a much earlier period. Similarly, the manufacturing of steel is evident from Chinese civilization, dating back to the Han dynasty (200 BCE to 25 CE). The Chinese are known to use high-carbon cast iron. There is a great deal of overlap and different regions moved from one period to another at different times. The late Stone Age, also called the Neolithic Age, was followed by the Chalcolithic Age from 4500 to 3500 BCE. During the Chalcolithic Age, humans began using copper (the name chalcolithic is derived from the Greek word khalkos for copper) for both decorative and utilitarian purposes. Because copper could be found as malleable pure copper nuggets, people could shape it with available stone tools—a property that no other common minerals possessed. A rise in the consumption of copper coincided with the development of a socioeconomic hierarchy, and the wealthy citizens possessed more copper than the proletariat. With this narrative, the timeline in Table 10.3 was devised. It was believed that the use of bronze was first developed in the Mesopotamian civilization of Sumeria and became common in other places later. This was a period characterized by a rapid rise in resource consumption and increasing diversification of products made by metalworking. Perhaps the most significant advancement in metal use was the discovery of how to make bronze, an alloy created by melting and combining the metals copper and tin. Although tin melts at a relatively low temperature (232 C), copper melts at 1983 C, a temperature too great to be easily achieved at the time. However, clever metal workers discovered that a mix of one part tin and three parts copper melts at 1675 C, which was low enough to make bronze manufacturing possible in many places. The 2008 discovery by Levy and Najjar (AP, 2008) revealed a different timeline. The 2006 dig has brought up new artifacts and with them a new suite of radiocarbon dates placing the bulk of industrial-scale production at Khirbat-en-Nahas (meaning “ruins of copper” in Arabic) in the 10th century BC—in line with the biblical narrative on the legendary rule of David and Solomon. The new data pushed back the archeological chronology some three centuries earlier than the current scholarly consensus. The research also documents a spike in metallurgic activity at the site during the 9th century BCE, which may also support the history of the Edomites as related by the Bible. This narrative is also supported by Quran (21:80): “. . .And We made the iron soft for him TABLE 10.3

Chronology of metal processing.

Archeological periods Biblical chronology

Egyptian chronology

1300 BCE Late Bronze IIB

Moses

1200 BCE Iron IA
B

Period of Judges

1000 BCE Iron IC or Iron IIA

United Kingdom (David and Solomon)

925 BCE

David Monarchy (Jehoshaphat of Judah
870
848) (945
924) (Ahaz of Judah
736
716)

Iron IIA or IIB

721 BCE

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1212) Merneptah (1212
1202) Ramesses III (1182
1151) Ramesses V (1145
1141) Shishak

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(and commanded him): Make coats of mail complete in every way, and arrange the plates properly. . ..”. This shows that it was David (a Prophet) that was made an expert in the use of iron, an armor for defense purposes. Quran talks about “copper spring” in 34:12 in the context of Prophet Solomon, who was the son of David. The consensus among archeological and historical researchers is that the iron age in the world started between 1200 and 1000 BCE and this was the period of Prophet David. At first, the Hittites in Syria and Asia Minor, who flourished between 2000 and 1200 BCE, discovered a method of melting and molding iron, but they guarded it as a close secret from the world, and it could not be put to common use. Later on, the Philistines came to know of it, but they too guarded it as a secret. The incessant defeats suffered by the Israelites at the hands of the Hittites and the Philistines before King Saul were due mainly to the use of chariots of iron in their wars by the latter. After him, Prophet David (1004
965 BCE) not only annexed the whole of Palestine and Jordan to the Israeli kingdom but also a major portion of Syria. This was the time when the secret of armor making closely guarded by the Hittites and the Philistines, became well known, and cheaper articles of daily use began to be made. The recent archeological excavations conducted in Edom, to the south of Palestine, which is rich in iron ore, have brought to light furnaces for melting and molding iron. The furnace excavated near Ezion-geber, a port on the Gulf of Aqabah, in the time of Prophet Solomon, seems to have been built on the principles which are used in the modern blast furnaces. It is therefore natural that Prophet David must have first of all utilized this discovery for war purposes because a little earlier, the hostile Canaanites around his kingdom had made life really difficult for his people. When the Hittite society of ancient Anatolia (modern-day Turkey) discovered how to process iron, their technological breakthrough was to add a small amount of charcoal (carbon) to rocks that contained iron. Pure iron melts at 1538 C, but adding carbon results in a carbon
iron mixture that melts at 1170 C. The Hittites also figured out that iron
carbon alloys could not be cold-worked like bronze but had to be hammered and shaped while hot. Thus, they invented the art of modern blacksmithing. The iron and alloys produced, once cooled, were much stronger and harder than bronze. After the time of the Hittites, it took another 500 to 1000 years for the iron age to reach central and northern Europe (Fig. 10.6). The source of iron used by the Hittites was metallic meteorites. Meteorites also contained a small amount of nickel that improved metal properties. Because iron-rich meteorites were not in abundance, the Hittites carefully guarded their invention of iron metal working for several centuries. During those centuries, the Hittites exercised military

The Iron Age

ancient near East central Europe

northern Europe 1500

1000

500

0

500

1000

FIGURE 10.6

1500

2000

Today

Today The Iron Age started in near east around 1500 BCE or even before.

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superiority over much of the Middle East and Egypt, where the weaker bronze was used in battle. However, by 1200 BCE, iron metalworking technology had spread across the Middle East, North Africa, and Europe, as well as to Asia. People discovered new sources of iron, and the Hittite empire disappeared. Copper, tin, iron, and nickel were all important during the early ages of humans, and they are equally important today. Those same metals—and many others—are key parts of a seemingly infinite number of products. For example, Fig. 10.7 shows the many minerals that provide elements that are in a smartphone. Copper makes up about 10% of the weight of a smartphone, and that copper is the key to moving around the electricity that powers the phone. Tin is used to make the liquid crystal display (LCD) screen and to solder electrical connections that transmit digital information. Iron is combined with the metals neodymium and boron to make magnets that are part of the microphone and speaker. And those are not the only elements in a smartphone; there are about 75 elements in all. Without any one of

FIGURE 10.7 Minerals that go into a smartphone.

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these elements, smartphones would not exist as they do. Nearly everything that we manufacture contains mineral resources, and the sources for these resources are mineral deposits. A major development occurred in 1751 CE when Benjamin Huntsman established a steelworks at Sheffield, Eng., where the steel was made by melting blister steel in clay crucibles at a temperature of 1500
1600 C (2700 F
2900 F), using coke as a fuel. Originally, the charge in the crucible weighed about 6 kg, but by 1870 it had increased to 30 kg, which, with a crucible weight of 10 kg, was the maximum a man could be expected to lift from a hot furnace. The liquid metal was cast to give an ingot about 75 mm in square section and 500 mm long, but multiple casts were also made. Sheffield became the center of crucible steel production; in 1873, the peak year, output was 110,000 tons—about half the world’s production. The crucible process spread to Sweden and France following the end of the Napoleonic Wars and then to Germany, where it was associated with Alfred Krupp’s works in Essen. A small crucible steelworks was started in Tokyo in 1895, and crucible steel was produced in Pittsburgh, PA, United States, from 1860, using a charge of wrought iron and pig iron. The crucible process allowed alloy steels to be produced for the first time since alloying elements could be added to the molten metal in the crucible, but it went into decline from the early 20th century, as electric-arc furnaces became more widely used. It is believed that the last crucible furnace in Sheffield was operated until 1968 (Website 10). While iron has been in use for over 1000 years, stainless steel is relatively new. The first stainless steel was produced around 100 years ago. In the intervening decades, it has revolutionized the modern world and is found in applications from building to healthcare to transportation. Harry Brearley invented the first true stainless steel in 1913. He added 12.8% chromium to iron and produced a metal that he found was resistant to both corrosion and rust. Brearley discovered this metal while looking for a solution to the problem of erosion in the gun barrels of the British army. Once stainless steel was first developed, improvements came rapidly. By 1919, a patent had been filed on martensitic stainless steel, a forerunner to today’s 410 stainless steel. In 1929, William J. Kroll discovered the process of precipitation-hardening stainless. The first duplex stainless steel was produced in Sweden in 1930.

10.2.3 Pipelines coatings The first industrial pipeline in the world is known to be the 40 km wooden tunnel of 40 km length that ran between Hallstadt and Ebensee in Austria. It involved cutting down 1300 tree trunks to a hollow shape and connecting them to avoid leaks. A more recent example is the Berlin (Germany) gas distribution system in the early 20th century. During that time, DENSO invented the corrosion prevention coating of Petroleum Tape. Coal tar and bitumen coatings are still in use in some countries (such as India). Very often these coatings got brittle, resulting in the formation of crevices and cracks and a significant decrease in adhesion to the steel surface (Table 10.4). After that period, the quest for a more effective coating led to the inventions of numerous products used as rehabilitation material. Initially, practically all paints were tar and bitumen based. They are both natural materials. Later, two-ply tapes of PVC with hotmelt or bitumen, two-ply tapes made of PVC with hotmelt or bitumen adhesives o two-ply tapes made of PE with hotmelt or butyl

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TABLE 10.4

Environmental stresses and their influence on coating materials.

Loads Corrosion defects are caused by

Coating defects caused by

Requirements Water

Vapor impermeability

Oxygen

Oxygen impermeability

Electrolyte Stray electrical current

Chemical impermeability Impermeability of ions Electrical isolation

Impact on transport and application

Impact resistance

Loads at transport and application

Indentation resistance

Compacting of soil

Pipe movement in soil

Indentation resistance Peel strength Lap shear resistance Lap shear resistance

Sunlight

UV Stability

Aggressive soil, high leveled operating temperatures

Aging resistance Chemical resistance

Microorganism Unsuitable application

Microbiological resistance Easy and secure application methods

FIGURE 10.8 Structure of PVC molecules.

rubber adhesive. Liquid coatings are relatively new corrosion prevention technologies that have been applied over shorter period of time. As the world entered the plastic era, Polyvinyl chloride (PVC) was synthesized by German chemist Eugen Baumann. The process was perfected by B.F. Goodrich Company who developed a method in 1926 to plasticize PVC by blending it with various additives, including the use of di-butyl phthalate by 1933 (Semon and Stahl, 1981). PVC may be manufactured from either naphtha or ethylene feedstock, following this equation, involving polymerization of the vinyl chloride monomer (VCM) into PVC (Fig. 10.8). About 80% of production involves suspension polymerization. Emulsion polymerization accounts for about 12%, and bulk polymerization accounts for 8%. Suspension polymerization affords particles with average diameters of 100
180 μm, whereas emulsion polymerization gives much smaller particles of average size of around 0.2 μm. VCM and water are introduced into the reactor along with a polymerization initiator and other additives. The contents of the reaction vessel are pressurized and continually mixed to maintain the suspension and ensure a uniform particle size of the PVC resin. The reaction is exothermic and thus requires cooling. As the volume is reduced during the reaction (PVC is denser than VCM), water is continually added to the mixture to maintain the suspension.

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In 1926, Waldo Semon tried to dehydrohalogenate high molecular weight PVC in a high boiling solvent to get an unsaturated polymer that might bond rubber to metal. Unexpectedly, he obtained plasticized PVC, a flexible product inert both electrically and chemically. This discovery opened the door to the commercialization of PVC, a plastic with an annual United States production now exceeding 6 billion pounds (Semon and Stahl, 1981). Special PVCs and PVC products have been developed taking advantage of the many favorable properties. Rigid structural products from house siding to pipes are becoming of increasing importance. Two main types of polymers have been utilized: (1) one prepared by suspension polymerization; (2) a special variety prepared by colloidal polymerization and spray drying. This latter material has been especially useful for making plastisols. Plasticizers and stabilizers were developed to maximize useful and nontoxic properties. VCM production and copolymerization evolved as lower-cost processes, higher-quality products, and greater manufacturing safety were introduced. Recent challenges for the industry have included pollution and carcinogenic hazards which have been overcome by imaginative new technologies. The rate of growth of the industry is shown graphically. The following types of additives feature prominently include: • • • • • • • • • • • •

Flame retardants PVC stabilizers PVC plasticizers (benzene free) Optical brighteners Resins Fillers Pigments Impact modifiers Lubricants Weather resistant High plasticity High gloss

Each of these comes with an increasingly greater threat to health and ultimate sustainability. It was in 1913 that the German chemist Friedrich Heinrich August Klatte received the first patent for PVC with his process for the polymerization of vinyl chloride using sunlight. Klatte later described the use of peroxides as catalysts for polymerizations: He would add small amounts of peroxide directly to the monomer. The liquid would gradually thicken until it became very viscous at which point Klatte would expose it to sunlight until it hardened completely. Once it had hardened, Klatte would smash the glass container, break the solid into smaller pieces, then dissolve these in a mixture of ketones and gasoline. Over the last century and beyond, the process of PVC manufacturing has become more indulgent in toxic additives. In the 1920s, Waldo Semon, B.F. Goodrich company, Charlotte, North Carolina, USA, discovered that the properties of PVC could be modified with the addition of plasticizers. Thus began its modern usage: PVC is always mixed with heat stabilizers, lubricants, plasticizers such as phthalic acid derivatives, fillers, and other additives to make processing possible. Production reached 32.3 million tons in 2011 and is expected to exceed 49 million tons by 2020. Construction, packaging, and electrical applications account for 75% of the PVC produced annually. PVC (CAS No: 9002
86-2) is a synthetic resin made from the

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polymerization of VCM (CAS No: 75
01
4). Occupational exposure to VCM peaked in the US and Europe in the 1950s but lasted until the 1970s (IARC, 2012). Table 10.5 shows the introduction of toxic chemicals in order to achieve certain flexibility in the PVC product. TABLE 10.5

Major patents and invention of toxic additives.

Publication

Publication date

Assignee

Title number

US2217163A

1940-10-08

Du Pont

Plastic composition

US2360306A

1944-10-10

Monsanto Chemicals

Plastic polyvinyl acetal compositions

US2459955A

1949-01-25

Shawinigan Chem Ltd

Polyvinyl acetate emulsion adhesive

US2628207A

1953-02-10

Standard Oil Dev Co

Terephthalate esters as plasticizers for polyvinyl resins

GB851753A

1960-10-19

Union Carbide Corp

Vinyl chloride resin compositions

GB985143A

1965-03-03

Hoechst Ag

Process for modifying the properties of fibers and films made from polymeric polyesters

US3224995A

1965-12-21

Ethyl Corp

PVC plasticized with dialkoxy alkyl homoterephthalates

US3431239A

1969-03-04

Prod Res & Chem Corp

Mercaptan terminated polyethers

US3725311A

1973-04-03

Thuron Industries

Low-temperature extrudable odor-neutralizing composition

US3764374A

1973-10-09

Eastman Kodak Co

Process for placing modifiers within polyester fibers and films

US3929867A

1975-12-30

Eastman Kodak CoMixed ester plastic additive

US4015044A1.

1977-03-29

Union Carbide Corporation

Process of bonding polyurethane-sealants and caulks

US4082712A

1978-04-04

Hooker Chemicals & Plastics Corp.

Process for curing sulfhydryl-terminated thioether polymers

US4110261A

1978-08-29

W & F Mfg. Co., Inc.

Fragrance-emitting article having a polymer
petroleum wax composition

JPS53117035A

1978-10-13

Kuraray Co Ltd

Pressure sensitive

US4221688A

1980-09-09

Dow Corning Corporation

Silicone emulsion which provides an elastomeric product and methods for preparation

US4253898A

1981-03-03

The B.F. Goodrich Company Bonding composition and microwave process for bonding together plastic components

US4331579A

1982-05-25

Congoleum Corp.

Adhesive to adhere imperviously and feltbacked vinyl sheet material to damp concrete (Continued)

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TABLE 10.5 (Continued) Publication

Publication date

US4362783A

Assignee

Title number

1982-12-07

Western Electric Company, Inc.

Polymer coatings and methods of applying same

US4366307A

1982-12-28

Products Research & Chemical Corp.

Liquid poly thioethers

US4376144A

1983-03-08

Monsanto Company

Treated fibers and bonded composites of cellulose fibers in vinyl chloride polymer characterized by an isocyanate bonding agent

US4401720A

1983-08-30

Eastman Kodak Comp.

PVC plastisol compositions

US4414267A

1983-11-08

Monsanto Company

Method for treating discontinuous cellulose fibers characterized by specific polymer-toplasticizer and polymer-plasticizer-to-fiber ratios, fibers thus treated and composites made from the treated fibers

US4515909A

1985-05-07

Kiyohito Sawano

Resinous composition for the prolonged release of fragrant substances

US4562173A

1985-12-31

Toho Titanium Co., Ltd.

Catalyst component for the polymerization of olefins and catalyst therefor

US4599376A

1986-07-08

Toyoda Gosei Kabushiki Kaisha

PVCcomposition

US4605465A

1986-08-12

W. R. Grace & Co.

UV and thermally curable, thermoplasticcontaining compositions

US4654390A

1987-03-31

The Dow Chemical Company

Monomeric plasticizers for halogen-containing resins

US4666765A

1987-05-19

Caldwell James

MSilicone coated fabric

US4764449A

1988-08-16

The Chromaline Corp.

Adherent sandblast photoresist laminate

US4792464A

1988-12-20

Martenson Irvin W

Corrosion coating composition

JPS6445452A

1989-02-17

Plus Teku Kk

Thermoplastic polymer composition

US4806590A

1989-02-21

Imperial Chemical Industries Plc

Aqueous-based sealant compositions

US4900771A

1990-02-13

Aster, Inc.

Hot-applied plastisol compositions

EP0397245A2

1990-11-14

The Procter & Gamble Company

Perfume particles for use in cleaning and conditioning compositions

US4975480A

1990-12-04

Bp Chemicals Ltd.

Crosslinkable silyl polymer composition

WO1991017302A1

1991-11-14

Westhulme Developments Ltd.

Printing inks, and methods of printing

US5071690A

1991-12-10

Diafoil Company, Ltd.

Moldable biaxially stretched polyester film (Continued)

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TABLE 10.5

(Continued)

Publication

Publication date

WO1992018601A1

Assignee

Title number

1992-10-29

Minnesota Mining And Manufacturing Company

Improvements in coated perfume particles

US5179138A

1993-01-12

Chisso Corporation

Process for producing a vinyl chloride resin composition for powder molding

US5236883A

1993-08-17

Oji Paper Co., Ltd.

Heat-sensitive recording material

JPH05262942A

1993-10-12

Asahi Denka Kogyo Kk

Chlorine-containing resin composition

US5288797A

1994-02-22

Tremco Ltd.

Moisture-curable polyurethane composition

US5326845A

1994-07-05

Dap Products Inc.

Moisture-curable silicone-urethane copolymer sealants

US5338788A

1994-08-16

Sunstar Giken Kabushiki Kaisha

PVCplastisol sealer composition

JPH06258772A

1994-09-16

Fuji Photo Film Co Ltd

Splicing and splice-releasing methods for roll film

DE4415888A1

1994-11-17

Basf Ag

Quick-setting, two-component sealing or filling compounds

US5366550A

1994-11-22

Tec Incorporated

Latex-modified cement-based thin set adhesive

US5401708A

1995-03-28

Kanzaki Paper Mfg. Co., Ltd.

Heat-sensitive recording material

US5432222A

1995-07-11

Sumitomo Chemical Company, Ltd.

PVCresin composition for powder molding

US5454801A

1995-10-03

Mcneil-Ppc, Inc.

Printed polymer coatings and method for making the same

JPH07286153A

1995-10-31

Sekisui Chem Co Ltd

Adhesive composition and paper tube produced by using the same adhesive composition

US5476889A

1995-12-19

Minnesota Mining And Manufacturing Company

Curable sealer and/or adhesive composition, and a method for coating same in a dry state with automotive paint, and coated substrates formed therewith

JPH0820668A

1996-01-23

Dainippon Ink & Chem Inc

Thermoplastic resin composition, adhesive, and adhesive base material

US5489618A

1996-02-06

Osi Specialties, Inc.

Process for preparing polyurethane foam

US5492960A

1996-02-20

Eastman Kodak Comp.

Method of making polymeric particles

US5494707A

1996-02-27

Mannington Mills, Inc.

Resilient floor covering and method of making the same

US5519072A

1996-05-21

National Starch And Chemical Investment Holding Corp.

Aqueous adhesive compositions for use in binding books (Continued)

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TABLE 10.5 (Continued) Publication

Publication date

US5523344A

Assignee

Title number

1996-06-04

H. B. Fuller Licensing & Financing, Inc.

Water-based adhesive formulation having enhanced characteristics

US5534609A

1996-07-09

Osi Specialties, Inc.

Polysiloxane compositions

US5535469A

1996-07-16

Terry; Raymond

Pliable abrasive pellet for abrading fabrics

US5539011A

1996-07-23

Osi Specialties, Inc.

Use of softening additives in polyurethane foam

US5559175A

1996-09-24

Hoechst Aktiengesellschaft

Polyvinyl acetals which can form emulsifier-free aqueous dispersions and redispersible dry powders, processes for their preparation and their use

US5571860A

1996-11-05

National Starch And Chemical Investment Holding Corp.

High-performance polyvinyl alcohol stabilized ethylene vinyl acetate adhesives

US5659001A

1997-08-19

Dow Corning S. A.

Moisture-curable compositions

US5670225A

1997-09-23

Oji-Yuka Synthetic Paper Co., Ltd.

Uniaxially stretched multilayered film and air baggage tag containing the same

US5681631A

1997-10-28

Minnesota Mining And Manufacturing Comp.

Graphics transfer article

US5698621A

1997-12-16

Achilles Usa, Inc.

Printable self-clinging PVC film and methods relating thereto

US5750278A

1998-05-12

Westinghouse Electric Corp. Self-cooling mono-container fuel cell generators and power plants using an array of such generators

US5767174A

1998-06-16

Asahi Glass Company, Ltd.

Vinyl chloride resin composition

US5869589A

1999-02-09

Raynolds; Peter Webb

Self-crosslinking aqueous dispersions

US5877268A

1999-03-02

Osi Specialties, Inc

Polyethers and polysiloxane copolymers manufactured with double metal cyanide catalysts

USRE36233E

1999-06-22

Osi Specialties, Inc.

Use of softening additives in polyurethane foam

US5919716A

1999-07-06

Eastman Chemical Company

Self-crosslinking aqueous dispersions

US6034168A

2000-03-07

Ato Findley, Inc.

Hot-melt adhesive having controllable water solubility

US6127026A

2000-10-03

Nike, Inc.

Flexible membranes

DE10016086A1

2000-10-12

Toyota Motor Co Ltd

Paste composition for use, e.g., as a sealant for vehicle bodywork, has good fluidity as a sol and comprises particulate polyurethane together with a plasticizer and a filler (Continued)

Pipelines

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10.2 Background and historical context

TABLE 10.5

(Continued)

Publication

Publication date

US6136884A

Assignee

Title number

2000-10-24

Eastman Chemical Company

Hair care compositions

US6136900A

2000-10-24

Witco Vinyl Additives Gmbh

Stabilized PVC

US6187125B1

2001-02-13

Arnco

Method for producing a deflation-proof pneumatic tire and tire filling composition having high resilience

US6221991B1

2001-04-24

Fmc Corporation

Methacrylate and acrylate polymers and processes for making same

US6231849B1

2001-05-15

George A. Schiller

Simulated seminal fluid

US6235830B1

2001-05-22

Sanyo Chemical Industries, Ltd.

Polyurethane resin-type composition for slush molding

US6245437B1

2001-06-12

Kureha Kagaku Kogyo K.K.

Gas-barrier composite film

US6284077B1

2001-09-04

Dap Products Inc.

Stable, foamed caulk and sealant compounds and methods of use thereof

US6303184B1

2001-10-16

Eastman Kodak Company

Method of forming a discontinuous polymer overcoat for imaging elements

US6323275B2

2001-11-27

Toagosei Co., Ltd.

Cyanoacrylate adhesive composition

US6391405B1

2002-05-21

Nike, Inc.

Fluid barrier membranes

US6414044B2

2002-07-02

Dap Products Inc.

Foamed caulk and sealant compounds

US6414077B1

2002-07-02

Schnee-Morehead, Inc.

Moisture-curable acrylic sealants

US6433097B1

2002-08-13

International Coatings Ltd.

Curable polymer compositions and their preparation

US6437071B1

2002-08-20

Kaneka Corporation

Silane-functionalized polyether composition

JP2002234983A

2002-08-23

C I Kasei Co Ltd

Agricultural PVC film

US6479584B1

2002-11-12

Kaneka Corporation

Resin composition, polymer, and process for producing polymer

WO2003029339A1

2003-04-10

Exxonmobil

Chemical Patents Inc. Plasticised PVC

US20030074833A1

2003-04-24

Wood Mervin G.

Benzotriazole/hals molecular combinations and compositions stabilized therewith

US6582786B1

2003-06-24

Nike, Inc.

Flexible membranes

JP2003301082A

2003-10-21

Mitsubishi Chemicals Corp

Vinyl chloride-based resin composition

US6638992B1

2003-10-28

Eastman Chemical Company

Hair care compositions (Continued)

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TABLE 10.5 (Continued) Publication

Publication date

CA2485133A1

2003-11-20

National Institute Of Novel raw material composition Advanced Industrial Science And Technology

US6656998B1

2003-12-02

Air Products Polymers, L.P.

Glossy paints containing emulsion polymers of vinyl acetate

US6656988B1

2003-12-02

Basf Aktiengesellschaft

Molding substances based on poly-C2-C6— alkylene terephthalates

US6670419B2

2003-12-30

Rohm And Haas Company

Method of toughening thermoplastic polymers and thermoplastic compositions produced thereby

US6675560B2

2004-01-13

Eastman Chemical Company

PVC food wrap formed from dioctyl terphthalate plasticizer, method of forming same and method of wrapping food therewith

US6706399B1

2004-03-16

Eastman Chemical Company

Non-blocking polymeric articles

US20040097625A1

2004-05-20

Vincent Bodart

Polymer compositions comprising telomers and articles or parts using these compositions

US6749836B1

2004-06-15

Eastman Chemical Company

Hair care compositions

US6750278B2

2004-06-15

Exxonmobil Research And Eng. Comp.

PVCresins

US6749861B2

2004-06-15

Lenco Laboratories, Llc

Fragrance containing insect-repellant compositions

US6762239B1

2004-07-13

National Starch And Chemical Investment Holding Corporation

Highly functionalized ethylene-vinyl acetate emulsion copolymers

US6784240B2

2004-08-31

Kaneka Corporation

Curable composition

US6803403B2

2004-10-12

Shinto Fine Co., Ltd.

Polymer emulsion

US6809147B1

2004-10-26

Sunstar Giken Kabushiki Kaisha

Thermosetting composition

US6825278B2

2004-11-30

Resolution Specialty Materials Llc

Modified pressure-sensitive adhesive

US6833423B2

2004-12-21

Bayer Polymers Llc

Moisture-curable polyether urethanes with reactive silane groups and their use as sealants, adhesives, and coatings

US6849675B2

2005-02-01

Acushnet Company

Golf ball comprising a plasticized polyurethane

US6855765B2

2005-02-15

National University of Singapore

Heat and hot water-resistant polyurethane sealant

Assignee

Title number

(Continued)

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TABLE 10.5

(Continued)

Publication

Publication date

Assignee

Title number

US6858260B2

2005-02-22

DeNovus LLC

Curable sealant composition

US6864317B1

2005-03-08

Kaneka Corporation

Curable compositions

US6872454B2

2005-03-29

Henkel Corporation

Impregnation sealants utilizing hydrosilation chemistry

US6884840B2

2005-04-26

Tesa Ag

Preparation of acrylic hot-melt pressuresensitive adhesives from aqueous disperse systems

US6887964B2

2005-05-03

Bayer Material Science LLC. Moisture-curable polyether urethanes with reactive silane groups and their use as sealants, adhesives, and coatings

US6896736B2

2005-05-24

Samsung Electronics Co., Ltd.

Photoresist purge control of semiconductor wafer coating equipment

US6900265B2

2005-05-31

Stepan Company

Antimicrobial polymer latexes derived from unsaturated quaternary ammonium compounds and antimicrobial coatings, sealants, adhesives, and elastomers produced from such latexes

CN1651229A

2005-08-10

马兴祥

Method of producing cable or optical cable carriage component element using PVC resin

US6933350B1

2005-08-23

Kaneka Corporation

Polymers having reactive functional groups at terminus and curable compositions comprising the same

US6946509B2

2005-09-20

Resolution Specialty Materials Llc

Acrylate-functional alkyd resins have improved dry time

US6958149B2

2005-10-25

Stryker Corporation

Repair of larynx, trachea, and other fibrocartilaginous tissues

US6960619B2

2005-11-01

Acryfoam Ltd.

Foamable photo-polymerized composition

US6964999B1

2005-11-15

Kaneka Corporation

Polymer and curable composition

US20050262758A1

2005-12-01

Gerald Allison

Transparent candle and method of making

US6977277B2

2005-12-20

Exxonmobil Res. & Eng. Company

PVCresins

US6979716B1

2005-12-27

Kaneka Corporation

Process for producing branched polymer and polymer

US7005095B2

2006-02-28

Nok Corporation

Process for production of vulcanized rubberresin composites

US7012148B2

2006-03-14

Trustees Of Dartmouth College

Compositions and methods for thionation during chemical synthesis reactions (Continued)

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TABLE 10.5 (Continued) Publication

Publication date

Assignee

US20060106168A1

2006-05-18

Kyoeisha Chemical Co., Ltd. Curable urethane resin composition

JP2006193603A

2006-07-27

Kaneka Corp

Curable composition

US20060276339A1

2006-12-07

Windsor J B

Methods and compositions for increasing the efficacy of biologically active ingredients

US20070012140A1

2007-01-18

Howlett Marc K

Beverage holder

US20070037926A1

2007-02-15

Olsen David J

PVCcompositions

CA2624332A1

2007-04-12

Henkel Kgaa

High-damping expandable material

US7208464B2

2007-04-24

The Procter & Gamble Company

Fragrance compositions

US20070110791A1

2007-05-17

Medea Myhra

Cleansing lotion with moisturizing, protecting, and odor-controlling agents and cloth comprising said lotion

US20070128148A1

2007-06-07

Whitehead Kenneth R

Aroma-releasing polymeric gel matrix

DE102006001795A1 2007-07-19

Oxeno Olefinchemie Gmbh

Terephthalic acid dialkyl esters and their use

US20070172382A1

2007-07-26

The Procter & Gamble Company

Method of freshening air

US20070230189A1

2007-10-04

Gruenbacher Dana P

Decorative luminary

CA2595012A1

2008-02-08

Celanese Emulsions Gmbh

Vinyl ester copolymer dispersions, their preparation, and use

US20080058450A1

2008-03-06

Eastman Chemical Company

Terephthalates as plasticizers in vinyl acetate polymer compositions

US20080057317A1

2008-03-06

Eastman Chemical Company

Sealant compositions having a novel plasticizer

US20080054089A1

2008-03-06

Eastman Chemical Company

Fragrance fixatives

US7361779B1

2008-04-22

Eastman Chemical Company

Low-melting mixtures of di-n-butyl and diisobutyl terephthalate

US9388293B2

2016

Eastman Chemical Co.

di-butyl terephthalate (DBTP) and diisobutyl terephthalate (DIBTP)

Title number

PVC, Polyvinyl chloride.

For some time, VCM was classified by the International Agency for Research on Cancer (IARC) as a certain carcinogen, group 1: angiosarcoma of the liver and hepatocellular carcinoma are associated with exposure to VCM. Additionally, suggestive evidence was found for connective and soft tissue malignant neoplasms, but weak evidence was found for the association with other cancers (IARC, 2012). Concerning the increased risk of lung cancer, some controversial results lead to a lack of overall evidence for relations with vinyl

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729

chloride, despite some suggestions reporting, among PVC packers and baggers, an increased risk of lung cancer with cumulative exposure to VCM. PVC is classified as a possible carcinogen (class 3) by IARC. Inhaled PVC dust (in particular with an aerodynamic diameter of less than 5 mm) may remain in the pulmonary interstitium for years, gradually releasing residual VCM, which may account for the neoplastic transformation of an epithelial cell (Waxweiler et al., 1981). Due to the residual presence of VCM and other additives, the European classification, labeling, and packaging (CLP) regulation reported that the PVC is one of the plastic polymers with the highest health hazard (highest hazard score 5) (Lithner, et al., 2011) Some epidemiological data on PVC baggers suggest the role of PVC dust as a “promoting” carcinogen operating in the last stages of lung carcinogenesis (Berrino, 2001). In 2022, Girardi et al. reported a study on baggers in the Porto Marghera cohort, taking into account the information on smoking habits provided in an interview conducted on a subsample of workers, which was never considered in previous analyses. They reported that long-term exposure to high levels of PVC dust might promote pulmonary carcinogenesis through persistent alveolar inflammation, alveolar macrophage activation, and release of growth factors. The science behind all these health hazards tells us that such processes are not sustainable.

10.2.4 Iron Historically, blister steel has been in use since the ancient epoch. In this process, iron billets were heated in a sealed clay pot, which was placed within a large bottle-shaped kilns that could hold about 10 to 14 tons of metal and about 20% of charcoal weight. When the kiln was heated, carbon from the charcoal diffused into the iron. In an attempt to achieve homogeneity, the initial product was removed from the kiln, forged, and again reheated with charcoal in the kiln. During the reheating process, carbon monoxide gas was formed internally at the nonmetallic inclusions; as a result, blisters formed on the steel surface, thus prompting the term “blister steel.” To produce weapons-grade quality, the carburizing, hammering, and carburizing processes had to be repeated about 20 times before the steel was finally quenched and tempered, and made ready for service. At about the beginning of the 18th century, coke produced from coal began to replace charcoal as the fuel for the blast furnace; as a result, cast iron became cheaper and even more widely used as an engineering material. The effect of replacing charcoal with coke on the intangible qualities of steel has not been studied. During the industrial revolution, the focus turned to mass production to keep up with the sudden growth in demand for steel for construction purposes. This was solved about the end of the 18th century by the puddling process, which converted the readily available blast furnace iron into wrought iron. In Britain, by 1860, there were 3400 puddling furnaces producing a total of 1.6 million tons per year—about half the world’s production of wrought iron. Puddling is a step in the manufacture of high-grade iron in a crucible or furnace. It was invented in ancient China during the Han Dynasty by the 1st century CE, then rediscovered in Great Britain during the Industrial Revolution (Chen, 1987). The molten pig iron was stirred in a reverberatory furnace, in an oxidizing environment,

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resulting in wrought iron. It was one of the most important processes of making the first appreciable volumes of valuable and useful bar iron (malleable wrought iron) without the use of charcoal. Eventually, the furnace would be used to make small quantities of specialty steel. Although it was not the first process to produce bar iron without charcoal, puddling was by far the most successful process and replaced the earlier potting and stamping processes, as well as the much older charcoal finery and bloomery processes. This enabled a great expansion of iron production at the beginning of the Industrial Revolution so far as the iron industry is concerned. Most 19th-century applications of wrought iron, including the Eiffel Tower, bridges, and the original framework of the Statue of Liberty, used puddled iron (Tylecote, 1992) After employing coke to replace charcoal, the next big change in energy source was the use of furnace gas. Blast furnace gas (BFG) is a by-product of blast furnaces that is generated when the iron ore is reduced with coke to metallic iron. It has a very low heating value, about 93 BTU/cubic foot (3.5 MJ/m3), because it consists of about 51 vol.% nitrogen and 22 vol.% carbon dioxide, which are not flammable. The rest amounts to around 22 vol.% carbon monoxide, which has a low heating value but has 5 vol.% of hydrogen. Per ton of steel produced via the blast furnace route, 2.5
3.5 tons of BFG gas is produced. It is commonly used as a fuel within the steelworks, but it can be used in boilers and power plants equipped to burn it. It may be combined with natural gas or coke oven gas before combustion or a flame support with richer gas or oil is provided to sustain combustion. Particulate matter is removed so that it can be burned more cleanly. The CO induces the following reaction. The main chemical reaction producing the molten iron is: Fe2 O3 1 3CO-2Fe 1 3CO2 At temperatures around 850 C, further down in the furnace, the iron(II,III) is reduced further to iron(II) oxide: Fe3 O4ðsÞ 1 COðgÞ -3FeOðsÞ 1 CO2ðgÞ Hot carbon dioxide, unreacted carbon monoxide, and nitrogen from the air pass up through the furnace as fresh feed material travels down into the reaction zone. As the material travels downward, the counter-current gases both preheat the feed charge and decompose the limestone to calcium oxide and carbon dioxide: CaCO3ðsÞ -CaOðsÞ 1 CO2ðgÞ The calcium oxide formed by decomposition reacts with various acidic impurities in the iron (notably silica), to form a fayalitic slag which is essentially calcium silicate, CaSiO3: SiO2 1 CaO-CaSiO3 As the iron(II) oxide moves down to the area with higher temperatures, ranging up to 1200 C, it is reduced further to iron metal: FeOðsÞ 1 COðgÞ -FeðsÞ 1 CO2ðgÞ

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The carbon dioxide formed in this process is re-reduced to carbon monoxide by the coke: CðsÞ 1 CO2ðgÞ -2COðgÞ The temperature-dependent equilibrium controlling the gas atmosphere in the furnace is called the Boudouard reaction: 2CO"CO2 1 C

10.2.4.1 Blast furnace gas BFG is produced during the iron oxide reduction in blast furnace iron making in which iron ore, coke, and limestone are heated and melted in a blast furnace and is an indigenous process gas of the steelworks industry (Pugh et al., 2013). BFG is a dynamic byproduct gas produced in large quantities with a composition comprising typically 18%
23% CO, 1%
5% H2, and a balance of N2 and CO2. Industrial operations lead to fluctuations in gas characteristics over short time periods. This can dissuade engineers from using the gas in increasingly complex technologies with perceived efficiency improvements such as gas turbines, a trait exacerbated by the “dirty” nature synonymous with industrial process gases. This body of work used the Tata Port Talbot integrated steelworks as a case study to analyze variation in gaseous composition, as a foundation for evaluation of the combustion dynamics associated with BFG. Varying levels of compositional fluctuation were observed, with H2 providing the most significant contributing factor to fuel characteristics. Particulate contamination was also studied as the gas cools and is distributed around the works, utilizing condensate analyses at multiple distances from the source. Particulate loading analyses yielded values of 0.04
0.1 mg/Nm3 at a distance of over 1.5 km from source, with results implying BFG is thermally scrubbed of contaminant matter through a mechanism of gas cooling and the amalgamation of condensate. The work performed therefore suggests the location of any installed equipment offers a significant contributory factor to performance. BFG has a high carbon monoxide (CO) content and a low heating value, typical 3900 MJ/m3 (IEA, 2007a, 2007b). The five primary components of BFG are N2, CO, CO2, H2O, and H2. The typical BFG composition in volume is N2 5 55.19%, CO 5 20.78%, CO2 5 21.27%, and H2 5 2.76% (Grammelis et al., 2016). The water content is removed by demisters following the cleaning process. This gas is used for the furnace mills, in gas engines, and for electricity and steam generation. Often, in the steel industry, BFG is used as an accessional to natural gas. Bojic and Mourdoukountas (2000) argued that in some cases, energy-saving techniques may result in higher CO2 emissions. For instance, when natural gas is mixed with waste BFG, energy savings are associated with higher CO2 emissions. They use the example of a pusher furnace of an average size pusher furnace, 30 m long, 13 m wide, and 3.9 m high and having a maximum production capacity of 250 t/h of steel slabs (Fig. 10.9). This furnace uses steel slabs of 4.5 6 12 m long, 0.6 6 2.05 m wide, and 0.15 6 0.25 m thick. The furnace is a large natural gas fuel consumer with a maximum consumption of 12,500 Nm3/h. downstream of the burners. The combustion products exit the furnace at around 1150 C, and are used in the heat recovery device to preheat furnace combustion air to 500 C.

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FIGURE

10.9 Pusher furnace (Grammelis et al., 2016), Solid fuel types for energy generation, in Fuel Flexible Energy Generation, Woodhead Publishing.

FIGURE 10.10 The ratio of CO2 emission per unit temperature for the steel slab heated at 1250 C and at 1200 C as a function of a content of the BFG in the fuel mixture, and for oxygen content in the combustion air.

In the pusher furnace, the steel slabs are heated to 1250 C to prepare them for hot rolling. To attain 12,508 C, the combustion temperature of the fuel must be 2150 C and 1800 C. In the steel mill, the BFG is used as a fuel in a pusher furnace to substitute for natural gas. The pusher furnace uses a fuel mixture composed of two combustible gases natural gas and BFG. The natural gas with the lower heating value of Hd 5 35,760 kJ/Nm3 contains 90.9% methane. The BFG generated during the steel-making process contains 28% carbon monoxide and 72% nitrogen. The BFG has Hd 5 3954 kJ/Nm3, that is, 9 times less than the Hd of the natural gas. The fuel mixture with 60% of the BFG has Hd 5 16,677 kJ/ Nm3. The mill retains excess oxygen that can be mixed with the combustion air. Fig. 10.10 displays the direct relationship between the ratio of the CO2 emissions per unit temperature for the steel slab heated to 1250 C and the slab heated to 1200 C and the BFG content in the fuel mixture. This relationship, however, depends on the oxygen content in the combustion air, that is, at any given level of the BFG content in the fuel mixture, changes in the oxygen content result in changes to the ratio of the CO2 emissions per unit temperature for the steel slab heated at 1250 C and the slab heated at 1200 C. For example, assuming a value of 40% for the BFG content in the fuel mixture the ratio of the

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CO2 emissions per unit temperature for the steel slab heated at 1250 C and the slab heated at 1200 C rises from 1.8 to 1.7 as the oxygen content in the combustion air rises from 21% to 25%. Questioning the consistency of CO2 emissions reduction policies through energy saving, this paper demonstrates a case where energy-saving techniques do not necessarily lead to lower pollution. Specifically, they revealed that (1) an increase of BFG content in mixed gas yields higher CO2 emissions, but not necessarily lower natural gas consumption, (2) an increase of the oxygen percentage in the combustion air leads to higher CO2 emissions, and to lower natural gas consumption, (3) an increase in the temperatures of the slab yields higher CO2 emissions and to higher natural gas consumption. To date, no modeling has been performed to assess the role of fuel source as the material balance calculations do not include intangibles, such as additives used during the processing of the fuel. This is also true for many additives added during various stages of mineral processing. The mining industry makes use of a wide range of chemical products at various process stages, from inorganic products to synthetic polymers, in order to improve the rheology control of the production process (de Moraesa et al., 2013). Historically, the use of such chemicals has increased exponentially as one explores new means to increase efficiency. It starts with the comminution process (grinding), which takes place so as to obtain fine materials from the ore. Wang and Forssberger (2003) give an overview of comminution technology to produce mineral powders, whose particle size, in most cases, is P80 , 20 μm. This pulverization itself gives rise to other problems. The processing of fine particles into decreased particle sizes follows a decrease in their mechanical forces. This makes the forces related to the electrostatic phenomena and to the discontinuity of the medium (viscosity) more significant. Sivamohan (1990) reviewed the difficulties in recovering very fine particles in mineral processing. In this review, the author points out that particles with small mass lead to the following phenomena in the flotation process: (1) low particle momentum; (2) hetero-coagulation; (3) particle entrainment in concentrates; (4) low probability of collision with a bubble; (5) difficulty in overcoming the energy barrier between particle and particle and particle and bubble. Typical mineral processing involves operations of comminution, separation by size, concentration, and transport which are carried out, when possible, in aqueous medium. He et al. (2004) reviewed the rheology of slurries at the stage of wet ultrafine grinding in the mineral industry. The following factors were identified: • • • • • •

solid concentration particle size distribution particle shape temperature pH of the slurry the use of dispersants.

In several steps of mineral processing, chemical additives are used aiming to minimize the effects of particle size and rheology of slurry. The chemical additives used in each study, as well as their function in each case, are summarized in Table 10.6. Bentonite is an effective, widely used binder in the iron ore pelletizing process, and its low price is an important factor in its extensive use. However, bentonite incorporates silica and alumina, which are undesirable contaminants in pellets. Additionally, it is a natural

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TABLE 10.6 Chemical additives used and their function in the process (Moraes et al., 2013). Material/process

Additive

Function

Parameters Particle size

Iron ore-ultrafine/recovery Sodium hexametaphosphate

Dispersant

Chemical composition Stirring time Zeta potential

Coal slurry/solid
liquid separation

Polyacrylamide

Flocculant

Filtration Moisture content Zeta potential

Fe3O4 in suspension/ recovery

Sodium dodecyl sulfonate

Surfactant used as dispersant

Contact angle pH Average diameter Zeta potential

Hematite/grinding

Acetone

Grinding aid

Hardness of hematite pH

Bentonite/dispersion

Sodium dodecyl sulfonate

Surfactant used as dispersant

Viscosity pH Size distribution Viscosity

Metallic mineral/grinding

Polyacrylamide

Dispersant

Percent solids Grinding path Energy expended Pulp density

Dolomite/grinding

Polycarboxylic acid

Grinding aid

Pulp viscosity Multitorque Grinding time Percent solids Size distribution

Iron ore fines/selective dispersion

Sodium humate

Dispersant

Stirring time pH Chemical composition Viscosity (Continued)

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TABLE 10.6

(Continued)

Material/process

Additive

Function

Parameters

Hematite/dispersion

Polyacrylic acid and polymethacrylic acid

Suspension stability

Zeta potential Size distribution Chemical composition

Metallic minerals/flotation

Organic polymers

Minerals/fine grinding

Organic and inorganic dispersants

Depressant Dispersant flocculant Rheology slurry control

Review paper Percent solids Size distribution Rotation Viscosity Temperature Particle shape Size distribution Zeta potential

Iron ore pulp/dispersion

Sodium hydroxide and nitric acid

Dispersion stability

Percent solids pH Rotation Zeta potential

Quartz/flotation

Polymer and surfactant

Cationic interaction

Minerals/grinding

Organic and inorganic dispersants

Grinding aid

Iron ore/grinding

Dispersants

Grinding aid

Time Rotation Rheological parameters Sedimentation Percent solids pH Rheological parameters

material with variable composition depending on its origin. The necessary amount to obtain a suitable binder effect is very large, around 0.5% by weight, which makes handling more difficult and increases logistics costs. A number of attempts to replace bentonite as a binder for iron ore agglomeration make use of organic binders. Organic binders have advantages over bentonite, as they do not insert contaminants, are used in smaller amounts, and can be eliminated during the pellet-burning process. The following patent documents may be cited as representative of the state of the technique: • US 3,806,414—describes a method for using a polymeric binder on wet iron ore, either alone or with bentonite. The binder in this case is a graphitized copolymer of acrylic acid with a polyhydroxy compound, cellulose derivatives, starches, sugars, etc.;

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• US 3,893,847—refers to a water-soluble, high molecular weight substantially linear polymer used as a binder, for example, polyacrylamide; • US 4,767,449—refers to a binder system composed of a polymeric binder, for example, polyacrylamide, dispersed in a nonaqueous medium and clay, for example, bentonite; • US 4,802,914—refers to a process comprising the application of a polymeric binder to the mineral particles in the form of a powder or nonaqueous medium in the presence of sufficient water to bind the particles; • US 5,002,607—refers to an agglomeration process comprising mixing the mineral particles to particles larger than 100 μm of a polymeric binder based on starch, cellulose, or ethylenically unsaturated monomers; • US 5,102,455—refers to an agglomeration process comprising the mixture of ore particles with a soluble, anionic polymer binder, preferably a copolymer of acrylamide and sodium acrylate, also including bentonite optionally, in a wet environment; • US 5,306,327—refers to a binder for mineral particles, based on natural starch and a soluble polymer, for example, pectin, amide derivatives of cellulose, acrylic or vinyl polymers, and others.

10.3 The science of corrosion Chemical reactions are inherent to any corrosion of metal. Chemical reactions induce voltage difference, thus creating electrochemical cells. In general, electrochemistry deals with oxidation and reduction reactions. Corrosion occurs because of the great tendency of metals to react electrochemically with oxygen, water, and alternative substances within the atmosphere. Both water and oxygen are highly reactive. Oxygen’s high reactivity is due to its biradical electron configuration. As shown in a molecular orbital drawing of O2, the two unpaired electrons make the molecule highly susceptible to bond formation. Oxygen has two allotropes (dioxygen, O2, and ozone, O3), both excellent oxidizing agents. Water is known to be the most potent solvent. Scientifically, water is also the most reactive. However, specifically, waterreactive substances are those that spontaneously undergo a chemical reaction with water, as they are highly reducing in nature. Notable examples include alkali metals, lithium through cesium, alkaline earth metals, and magnesium through barium. In this context, the term anode is employed to explain the portion of the metal surface that is undergoing corrosion, whereas the term cathode is employed to explain the metal surface that consumes the electrons created by the corrosion reaction. An electrochemical reaction involves oxidation and reduction. On earth, oxygen is the most abundant element, oxidized form is the natural state of any ore. The following elements are the most abundant in the earth’s crust. Fig. 10.11 depicts the distribution. 1. 2. 3. 4. 5. 6. 7.

Oxygen: 46.1% Silicon: 28.2% Aluminum: 8.23% Iron: 5.63% Calcium: 4.15% Sodium: 2.36% Magnesium: 2.33%

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Others 0.1% Hydrogen 0.1%

Titanium: 0.6% Potassium 2.1% Magnesium 2.3% Sodium 4.2%

Oxygen 46.1%

Calcium 4.2% Iron 5.6% Aluminium 8.2%

Silicon 28.2% FIGURE 10.11 TABLE 10.7 Ore resource

Distribution of abundant elements in the earth crust.

Natural abundance, economical ore grade, and concentration factors for some metals.

Metal concentration in average crustal rock (wt.%)

Minimum ore grade for profitable extraction

Economical concentration factor

Aluminum 8.2

30

4

Iron

5.6

20

4

Sodium

2.4

40

17

Manganese 0.09

35

370

Chromium 0.01

30

2940

Nickel

0.008

0.5

60

Zinc

0.007

4.0

570

Lead

0.001

4.0

2900

Copper

0.006

0.5

80

Tin

0.0002

0.5

2500

8. Potassium: 2.09% 9. Titanium: 0.565% 10. Hydrogen: 0.140% As shown in Table 10.7, some important elements makeup very small percentages of Earth’s crust; nevertheless, natural processes concentrate them in particular minerals and in particular places.

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The economical concentration factor listed in the Table 10.7 is the ratio of typical minimum economical ore concentration to average crustal concentration. For example, the average crustal abundance of chromium is about 0.01 wt.%. Chromium ore can sometimes be profitable if it contains 30 wt.% chromium. The necessary concentration factor is therefore nearly 3000—chromium must be concentrated at least 3000 times to create profitable ore. The table compares economical concentration factors for a dozen different metals. They are ordered from those most abundant (top) to those that are rare (bottom). Concentration factors range from 4 for aluminum and iron, to nearly 3000 for tin, chromium, and lead. Elements that occur in high abundance do not need a high concentration factor to make mining economical. In contrast, less common chromium, lead, tin, and zinc require great concentrations to be profitably mined (see Table 10.7). We mine relatively common elements, such as iron nd aluminum, in many places worldwide; we mine rarer elements, including tin, chromium, or lead, in far fewer places. The most common forms of these ores are listed in Table 10.8. Table 10.9 shows common forms of oxides and hydroxides. They represent the natural states of these metals.

TABLE 10.8 Common ore minerals and their natural states. Metal

Mineral

Formula

Al

Gibbsite Boehmite Diaspore Magnetite Hematite Goethite Siderite Pyrite Copper Chalcopyrite Bornite Chalcocite Covellite Pentlandite Garnierite Sphalerite Wurtzite Zincite Franklinite Hausmannite Polianite Pyrolusite Cassiterite Chromite

Al(OH)3 AlO(OH) AlO(OH) Fe3O4 Fe2O3 FeO(OH) FeCO3 FeS2 Cu CuFeS2 Cu5FeS4 Cu2S CuS (Ni,Fe)9S8 (Ni,Mg)3Si2O5(OH)4 ZnS ZnS ZnO ZnFe2O4 Mn3O4 MnO2 MnO2 SnO2 FeCr2O4

Galena Cerussite Gold Calaverite

PbS PbCO3 Au AuTe2

Fe

Cu

Ni Zn

Mn

Cr Pb Ag

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TABLE 10.9

Oxides and hydroxides.

Oxide and hydroxide minerals Oxides Corundum

AlsO3

Periclase

MgO

Magnetite

Fe3O4

Hematite

Fe2O3

Pyrolusite

MnO2

Rutile

TiO2

Cassiterite

SnO2

Ilmenite

FeTiO3

Spinel

MgAl2O4

Chromite

FeCr2O4

Hydroxides Gibbsite

Al(OH)3

Diaspore

AlO(OH)

Brucite

Mg(OH)2

Goethite

FeO(OH)

Manganite

MnO(OH)

Oxides and hydroxides are often grouped together because they have similar compositions and atomic arrangements. The table to the left lists the most common of these minerals. These minerals often have similar properties, and most have relatively simple and related formulas. Oxide minerals consist of metal cations bonded to O22. Hydroxide minerals contain (OH)
anion molecules in place of all or some O22. A primary difference between oxides and hydroxides is the temperatures at which they form and are stable. Hydroxides are unstable at high temperatures; they exist in lowtemperature environments and are common products of alteration and weathering. Other oxide minerals—for example, magnetite and ilmenite—are high-temperature minerals generally associated with igneous or metamorphic rocks. In fact, most igneous and metamorphic rocks contain oxide minerals. Typically they are present in minor amounts, are easily overlooked, and may be difficult to identify. The next group is sulfides and sulfosalts, as shown in Table 10.10. Metallic ore deposits contain many different sulfides and related ore minerals. Most are quite rare. Table 10.10 shows more important minerals. Pyrite (iron sulfide) is the most common. Other relatively common sulfides include chalcopyrite (copper iron sulfide), molybdenite (molybdenum sulfide), sphalerite (zinc sulfide), galena (lead sulfide), and

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TABLE 10.10

Sulfides and sulfosalts.

Sulfide and sulfosalt ore minerals Sulfides *Pyrite

FeS2

*Chalcopyrite

CuFeS2

*Molybdenite

MoS2

Sphalerite

ZnS

*Galena

PbS

Cinnabar

HgS

*Acanthite

Ag2S

*Chalcocite

Cu2S

*Bornite

Cu5FeS4

*Pyrrhotite

Fe1-xS

*Millerite

NiS

*Pentlandite

(Fe,Ni)9S8

Covellite

CuS

Realgar

AsS

Orpiment

As2S3

*Stibnite

Sb2S3

*Marcasite

FeS2

Sulfosalts *Cobaltite

(Co,Fe)AsS

*Arsenopyrite

FeAsS

Pyrargyrite

Ag3SbS3

*Tetrahedrite

Cu12Sb4S13

Enargite

Cu3AsS4

* indicates generally metallic.

cinnabar (mercury sulfide). The others in the table are less abundant but are occasionally concentrated in particular deposits. Sulfide minerals (such as pyrite) contain one or several metallic elements and sulfur is the only nonmetallic element. Bonding is variable: generally either covalent, metallic, or a combination of both. Metallic bonding, too, is important in some species. Other very uncommon minerals grouped with the sulfides (because of similar properties) contain selenium (the selenides), tellurium (the tellurides), or bismuth (the bismuthides) instead of sulfur. A related group of minerals, the sulfosalts, contains the semimetals arsenic and

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antimony in place of some metal atoms. Because many sulfides have similar atomic arrangements, solid solutions between them are common. The same holds true for the sulfosalts. Primary sulfide minerals consist of sulfur and reduced metals. When exposed to oxygen-rich-groundwaters, or to the atmosphere at Earth’s surface, they easily oxidize or break down in other ways. Oxidation can alter the original mineral’s color or texture. It can also create new minerals. Thus, iron-bearing sulfides may turn into iron oxide (magnetite or hematite), iron hydroxide (limonite or goethite), or iron carbonate (siderite). Galena (lead sulfide) may become cerussite (lead carbonate). Copper sulfides may become azurite or malachite (both hydrated copper carbonates). Sulfide minerals often form in common associations. Pyrite, sphalerite, and pyrrhotite are frequently found together, as are chalcopyrite, pyrite, and bornite or pyrrhotite. In some carbonate-hosted deposits, sphalerite and galena occur together. We can depict sulfide associations using triangular composition diagrams. Box 9
4 presents a detailed discussion of Cu
Fe
S ore minerals and explains how we use triangular diagrams to show solid solution compositions. Unlike other mineral groups, especially the silicates, color is sometimes a good way to identify sulfide minerals, especially for those with metallic lusters (marked with * in Table 10.10). The reason is that transition metals often control color, and the color of sulfides is often due to the metals they contain. So, color is helpful. Sulfide minerals, however, show lots of variation in appearance, especially if they are tarnished. Space does not permit including photos of all the different sulfides here, but some examples are below. The most common kinds of corrosion result from electrochemical reactions. General corrosion occurs when most or all of the surface elements come in contact with air and oxidizes to form a state closer to the natural state of the mother ore. Most metals are easily oxidized: they tend to lose electrons to oxygen (and other substances) in the air or in water. As oxygen is reduced (gains electrons), it forms an oxide with the metal. Some of the governing equations come from high-temperature cases. Considering this aspect, the following stages are identified: Stage I: After an initial period of transient oxidation, steady-state growth of the protective scale occurs, in which diffusion of cations and/or anions in the scale is the rate-determining step of the scale growth process. Based on classical oxidation theory (Rapp, 1965), the scale growth exhibits a parabolic dependence of scale thickness as function of time: X2 5 2kp t

(10.1)

where X is the scale thickness, t is the time, and kp is the parabolic rate constant. Commonly, parabolic oxidation kinetics are expressed in terms of area-specific weight gain (Δm) as a result of oxygen uptake:



ðΔmÞ2 5 2kw t

(10.2)

where kw is the parabolic rate constant. In many cases, the oxidation kinetics do not obey an ideal parabolic behavior. This may be related to a significant contribution of grain boundary diffusion in combination with changing oxide grain size in the overall oxidation process. Also, void formation or time-

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dependent incorporation of minor alloying additions with high oxygen affinity (e.g., Mn, Si, Al, Ti, Nb) into the scale may result in deviations from ideal behavior for the primary protective oxide species. In the case of subparabolic oxidation, the kinetics may be described by Quadakkers et al. (2004):



Δm 5 k tn

(10.3)

in which k is the power law rate constant and n is the oxidation exponent whereby n , 0.5. Fig. 10.12 compares the range of oxidation rates at different temperatures for the major oxides. Above 1100 C, the oxide on Si has the slowest growth rate, but the establishment of a protective surface SiO2 layer is difficult; more details are presented in Section 1.10.4. The kinetics for refractory metals, such as Nb, are only parabolic at low temperatures. Linear kinetics and oxide volatilization are often observed at higher temperatures (Section 1.10.3). The rate for Co-oxidation shows two activation energies that are associated with the formation of Co3O4 above a growing CoO layer at lower temperatures. For iron, the lower temperature rate is dominated by the growth of magnetite (Fe3O4), while, at high temperatures, above $570 C, the rate is mainly dominated by the growth of the very nonstoichiometric wu¨stite (FeO); since deviation from stoichiometry decreases with increasing temperature, the activation energy is seen to diminish with temperature. Stage II: Thermally induced stresses during cooling due to the mismatch in thermal expansion coefficients between alloy and oxide and even oxide growth stresses may lead to local or widespread scale spallation. This occurs after the scale thickens and scale FIGURE 10.12 Summary of parabolic oxidation rate constants for some of the metals (Hou, 2010).

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defects with a critical size form, for example, as a result of vacancy condensation (Przybilla and Schu¨tze, 2002). Stage III: After long-term exposures, the oxidation processes may result in metal concentrations at the scale/alloy interfaces which are substantially lower than that given by Eq. (10.3). If a critical depletion level is reached, the protective chromia scale can no longer heal and nonprotective oxides form resulting in breakaway oxidation. When reduction and oxidation take place on different kinds of metal in contact with one another, the process is called galvanic corrosion. In electrolytic corrosion, which occurs most commonly in electronic equipment, water or other moisture becomes trapped between two electrical contacts that have an electrical voltage applied between them.

10.3.1 Natural protection Some metals acquire a natural passivity or corrosion resistance. This occurs when the metal reacts with, or corrodes in, the oxygen in the air. The result is a thin oxide film that blocks the metal’s tendency to undergo further reaction. The patina that forms on copper and the weathering of certain sculpture materials are examples. The protection fails if the thin film is damaged or destroyed by structural stress—for example, on a bridge—or by scraping or scratching. In such cases, the material may passivate again, but if that is not possible, only parts of the object corrode. Then the damage is often worse because it is concentrated at these sites. Corrosion reactions are frequently electrochemical in nature. Hydrogen evolution and oxygen reduction are the two most prevalent reactions that keep a corrosion process progressing in acidic media and neutral/alkaline environments, respectively. Corrosion in metals and alloys is caused by a variety of factors; some of the most important environmental causes are schematically shown in Fig. 10.13. Aside from the factors depicted in this figure, the temperature of the environment has a significant effect on corrosion. Furthermore, the presence of some bacteria species inside a biofilm on steel can speed up and promote the progress of an already existing corrosion process. It is worth adding that corrosion chemistry is rapidly evolving, and each chemical process is scrutinized from the standpoints of economics, environmental impact, and safety. FIGURE 10.13 Environmental causes of metal corrosion (Zaker et al., 2022). Zakeri, A., Bahmani, E., Aghdam, A.S.R., 2022, Plant extracts as sustainable and green corrosion inhibitors for protection of ferrous metals in corrosive media: A mini review, Corrosion Communications, Volume 5, Pages 25-38.

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Let’s examine this process of natural passivity. The concentration of the species can be very different in the bulk solution and at the corroding steel surface due to corrosion, mass transfer effects, and chemical reactions. One usually knows the bulk species concentration, however, the electrochemical corrosion process depends on the surface concentrations. Therefore, the surface concentrations need to be estimated by calculation. Commonly, two calculation “nodes” are used in the computational domain: one for the species concentrations in the bulk solution and the other for the species concentrations in the thin water layer adjacent to the corroding metal surface (Nesic and Sun, 2010. The concentrations of chemical species in the bulk solution can be calculated using a standard water chemistry equilibrium model. The concentrations of species at the corroding steel surface need to be calculated in a way that ensures that all the key physicochemical processes that affect the surface concentrations are accounted for. They are as follows: 1. Homogenous chemical reactions close to the steel surface; 2. Electrochemical reactions at the steel surface; 3. Transport of species between the steel surface and the bulk, including convection and diffusion through the boundary layer as well as electromigration due to establishment of electrical potential gradients. These three physicochemical processes are interconnected and can be expressed by writing a material balance or mass conservation equation for a thin surface water layer. Ne;j2Nw;j @csurface;j 5 Rj 1 @t Δx

(10.4)

where csurface, j is the concentration of species j, Ne, j is the flux of species j on the east boundary due to mass transfer from the bulk solution to the surface, Nw, j is the flux of species j on the east boundary due to electrochemical reactions at the metal surface, and Rj is the source/sink term due to homogeneous chemical reactions involving species j. As the surface of the metal begins to corrode the reaction rate decreases, thus making less reactant (e.g., oxygen) available. This process creates a protective layer (Fig. 10.14). Corrosion rate increases with a decrease in pH as expected since the corrosivity of the solution increases and the solubility of iron increases as well. The decrease of corrosion rate FIGURE 10.14

100

Corrosion rate, mm/y

dence on pH.

10

1

0.1 1

2

3

4

5

pH

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with time is much faster at pH 6.0 due to the formation of a denser iron sulfide layer. Within the range of about pH 4
10, the corrosion rate is independent of pH and depends only on how rapidly oxygen diffuses to the metal surface. The major diffusion barrier of hydrous ferrous oxide is continuously renewed by the corrosion process. Regardless of the observed pH of water within this range, the surface of iron is always in contact with an alkaline solution of saturated hydrous ferrous oxide, the observed pH of which is about 9.5. Above pH 10, an increase in the alkalinity of the environment raises the pH of the iron surface. The corrosion rate correspondingly decreases because iron becomes increasingly passive in the presence of alkalis and dissolved oxygen. In the region of pH 4
10, the corrosion rate depends only on the rate of diffusion of oxygen to the available cathodic surface. The extent of the cathodic surface is apparently not important. The total weight loss of these specimens compared to control specimens not plated was found to be the same. All oxygen reaching the copper surface, acting as cathode, was reduced in accord with the reaction H2 O 1 1=2O2 -2OH2 2 2e2 and an equivalent amount of Fe21 was formed at the iron surface acting as anode. In the acid range, pH , 4, oxygen is not controlled, and the corrosion reaction is established, in part, by the rate of hydrogen evolution. The latter, in turn, depends on the hydrogen overpotential of various impurities or phases present in specific steels or irons. The rate becomes sufficiently high in this pH range to make anodic polarization a possible contributing factor (i.e., mixed control). Because cementite, Fe3 C, is a phase of low hydrogen overpotential, a low-carbon steel corrodes in acids at a lower rate than does a high-carbon steel. Similarly, heat treatment affecting the presence and size of cementite particles can appreciably alter the corrosion rate. Furthermore, cold-rolled steel corrodes more rapidly in acids than does an annealed or stress-relieved steel because cold working produces finely dispersed low-overpotential areas originating largely from interstitial nitrogen and carbon. Harmful corrosion can be prevented in numerous ways. Electrical currents can produce passive films on metals that do not normally have them. Some metals are more stable in particular environments than others, and scientists have invented alloys such as stainless steel to improve performance under particular conditions. Some metals can be treated with lasers to give them a noncrystalline structure, which resists corrosion. In galvanization, iron or steel is coated with the more active zinc; this forms a galvanic cell where the zinc corrodes rather than the iron. Other metals are protected by electroplating with an inert or passivating metal. Nonmetallic coatings—plastics, paints, and oils—can also prevent corrosion. Specimens were selected with a carbon content of 0.04%, 0.13%, and 0.21% in order to estimate the effect of carbon content on the corrosion rate of pipe steel. Here, both laboratory experiment data and also actual results of measuring the pipe wall thickness after prolonged operation were used. Fig. 10.15 shows the trend of corrosion rate as a function of carbon content. The very fact that corrosion consists of a minimum of one chemical reaction and one reduction reaction isn’t entirely obvious because both reactions are usually combined in one piece of metal (e.g., zinc), as illustrated schematically below. Note that the electron sign is a matter of convention. The following electrical terms are widely used in electrochemistry and corrosion science:

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FIGURE 10.15

Effect of carbon content on pipe steel average corrosion rate. Source: Modified from Pleshivtsev et al. (2009).

Corrosion rate, mm/y

0.18 0.14 0.10 0.06 0

0.05

0.10 0.15 0.20 Carbon content, %

0.25

Electric potential (E) is defined as the capacity of an electric field to do work, and it is measured in volts (1 volt 5 1 joule/coulomb; joule 5 107 ergs [energy or work]; coulomb 5 quantity of electricity; ampere 5 1 coulomb/sec). Electric potential can be described as follows: I (10.5) R In the equation, the constant of proportionality, R, is called Resistance and has units of ohms, with the symbol Ω (volt/ampere). The same formula can be rewritten in order to calculate the current and resistance respectively as follows: V (10.6) I5 R V (10.7) R5 I E5

Ohm’s law only holds true if the provided temperature and the other physical factors remain constant. In certain components, increasing the current raises the temperature. An example of this is the filament of a light bulb, in which the temperature rises as the current is increased. In this case, Ohm’s law cannot be applied. The lightbulb filament violates Ohm’s Law. Electric current (I) is a movement of electrically charged particles and is measured in amperes. Ohm’s Law: Ohm’s law states that the voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions and temperature, remain constant. Fig. 10.16 shows a piece of zinc immersed in acid solution, undergoing corrosion. At some point on the surface, Zn is transformed into Zn ions losing electrons. These electrons go through the solid conducting metal to alternative sites on the metal surface, wherever hydrogen (H) ions are reduced to hydrogen gas consistent with the following equation: Anodic reaction: ZnðsÞ-Zn21 1 2e2 Cathodic reaction: 2H 1 -Zn21 1 H2 ðgÞ

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FIGURE 10.16 Electrochemical reactions during the corrosion of Zn in air-free HCL.

Zn2+

e– H+

H+ e– H2

H+ H+ Zinc FIGURE 10.17

Occurrence of corrosion on metal.

−

+

+ − −

+

+

Metal

These equations illustrate the character of an electrochemical reaction in zinc. Throughout such a reaction, electrons are transferred, or to view it in a different way, an oxidation reaction happens in conjunction with a reduction reaction. Overall corrosion reaction: Zn 1 2H1 -Zn21 1 H2 ðgÞ Therefore, in electrochemistry, anodic and cathodic reactions are occurring simultaneously and at equivalent rates. However, corrosion happens solely in the areas that function as anodes. Any metal surface, similar to the situation for zinc, is a composite of electrodes electrically short-circuited through the body of the metal itself (Fig. 10.17). So as long as the metal remains dry, local-action current and corrosion are not observed. But on exposure of

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the metal to water or aqueous solutions, local-action cells are able to function and are accompanied by chemical conversion of the metal to corrosion products. , A difference in rates is observed impurities now enter predominantly as electrodes of n cells. With iron or steel in aerated water, for example, the negative electrodes are commonly portions of the iron surface itself covered perhaps by porous rust (iron oxides); and positive electrodes are areas exposed to oxygen, with the positive and negative electrode areas interchanging and shifting from place to place as the corrosion reaction proceeds. Accordingly, high-purity iron in air-saturated water corrodes at essentially the same rate as impure or commercial iron. A difference in rates is observed in acids, however, because impurities now enter predominantly as electrodes of local-action cells. Although increase in oxygen concentration at first accelerates corrosion of iron, it is found that, beyond a critical concentration, the corrosion drops again to a low value. In distilled water, the critical concentration of oxygen above which corrosion decreases again is about 12 mL O2/L (Fig. 10.18). This value increases with dissolved salts and with temperature, and it decreases with an increase in velocity and pH. At pH of about 10, the critical oxygen concentration reaches the value for air-saturated water (6 mL O2/L) and is still less for more alkaline solutions. The decrease in corrosion rate is caused by the passivation of iron by oxygen, as shown by potentials of iron in air-saturated water (Table 10.11). FIGURE 10.18

8

Corrosion rate, gmd

Corresponds to air saturation 6

Effect of oxygen concentration on corrosion of mild steel in slowly moving distilled water, 48-h test, 25 C.

4

2

0 0

2

10 15 20 25 4 6 Concentration of dissolved oxygen, mL/Liter

TABLE 10.11 Effect of dissolved oxygen on corrosion of mild steel in acids. Corrosion rate (mm/y) Acid

Under 02

Under H2

Ratio

6% acetic

13.9

0.16

87

6% H2SO4

9.1

0.79

12

4% HCl

12.2

0.79

15

0.04% HCl

9.9

0.14

71

1.2% HNO3

46

40

1.2

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The doctrine of electrochemical reactions is employed in a Daniell cell, during which copper and zinc metals are immersed in solutions of their individual sulfates. A Daniell cell is an electrochemical cell that carries out chemical reactions to produce electricity. In the Daniell cell, zinc metal is made of the anode, and copper metal is the cathode. The zinc anode is dipped in Zinc salt solution and the copper cathode is dipped in the copper salt solution. In a Daniell cell, electrons are transferred from the corroding zinc to the copper through an electrically conducting path as an electric current. Zinc loses electrons more readily than copper, which means that putting zinc and copper metal in solutions of their salts will cause electrons to flow through an external wire that leads from the zinc to the copper as per the following reactions: Zinc anode: ZnðsÞ-Zn21 1 2e2 Copper cathode: Cu21 1 2e2 -CuðsÞ The difference in corrosion potential between the two metals will usually cause a scenario that’s referred to as galvanic corrosion, which was named in honor of its discoverer, Luigi Galvani. Galvanic corrosion (also called “dissimilar metal corrosion” or wrongly “electrolysis”) refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte. It occurs when two (or more) dissimilar metals are brought into electrical contact underwater (Fig. 10.19). This situation is common in natural corrosion cells wherever the setting is the electrolyte that completes the corrosion cell. The conduction of a liquid atmosphere like soil, concrete, or water has usually been associated with its corrosivity. The short-hand description within the following equation is valid for each Daniell cell configuration. 21 22 ð2ÞZn=Zn21 ; So 22 4 ðConc1 Þ ==Cu ; SO 4 ðConc2 Þ =Cuð1Þ

This equation identifies the zinc electrode as the anode because it is negative in the case of a spontaneous reaction, while the copper electrode is the cathode due to its positive charge. The anodic method applies to a scenario in which metals are connected as anode in an electrochemical cell. In this, anodic polarization takes place, which leads to the formation of a passive film directly on the metal surface. This is also due to the DC potential applied, giving FIGURE 10.19 Electrical conti-

O2

nuity between the two metals.

water

Fe2+

H 2O Rust Fe2O3 xH2O

iron

anodic site 2+

Fe(s) → Fe (aq) + 2e

O2

cathodic site

e– –

O2(g) + 4H+(aq) + 4e– → 2H2O(I)

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protection to the metal against the possible damages that can be brought on by corrosion. The anodic method is the preferred type of protection for storage vessels made from mild steel that usually contains alkaline or acidic fluids combined with sulfuric acid in concentrated solutions. An anodic protection system keeps metal surfaces in a passive state. It involves low-current DC power combined with feedback control to offer protection against corrosion. Except in rare cases, there is no homogeneity of materials, metals, or alloys in buildings or in mechanically joined structures. For example, metallic fittings in aluminum are always joined with screws in stainless steel, while accessories such as hinges, filters, lift-off hinges are in stainless steel or chrome-plated steel, or even in brass. Under appropriate conditions, there is a risk of galvanic corrosion of aluminum. Galvanic corrosion of aluminum in heterogeneous assemblies exposed to weathering obeys the rules given above. It depends on several factors (Vargel, 2021): 1. The nature of the metals and alloys; 2. The type of atmosphere or ambiance. For instance, marine atmosphere leads to the most severe galvanic corrosion because of the presence of chlorides; 3. The conductivity of the moisture film; 4. The frequency of moistening: galvanic corrosion requires an electrolyte, which means that the contact area must be wet. Its intensity, therefore, depends on the local climatic conditions: rain, relative humidity, etc. Atmospheric galvanic corrosion will always be limited to the contact area. Under appropriate conditions, it may lead to severe damage: roofing that is perforated around bolts or screws, electrical components that are corroded at contacts with components made of copper or copper alloys, etc. In practice, contacts with stainless steel and zinc or cadmium-coated steel are the most common ones in construction, especially in metallic fittings. Experience throughout the world demonstrates that even without insulation between the two metals, galvanic corrosion does not lead to problems in these assemblies, if the design is such that any retention of moisture is avoided. Areas where moisture is retained, and where rainwater or condensed water can be trapped permanently or for long periods of time. This is often observed with embeddings that form a basin that can retain water. Galvanic corrosion is observed in contact with embedded steel pins. At the assembly points of roofing sheet and cladding panels, in substantially humid and aggressive environments. As an example, in coastal areas, strong galvanic corrosion around bolts can sometimes be found, because the felt used for insulation retains water, has disappeared, or has been compressed, so that the aluminum comes into direct contact with the steel washers and bolts that are often rusty. It is preferred over cathodic protection, especially for particular metals such as stainless steel and steel alloys. Yet, it must be noted that it is only effective when the power supply of DC is closely monitored. Thus, industries should implement careful monitoring of the direct current supply within an anodic system. The anodic method is vital in industry, especially in aerospace and other crucial situations and applications where the cathodic method is considered to be not a cost-effective alternative for corrosion protection. In the case of iron, the corrosion reaction for iron (Fe), which involves the reduction of hydrogen ions to hydrogen gas, is consistent with the electrochemical reaction of zinc in hydrogen chloride (HCl). This hydrogen evolution reaction

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happens in a variety of metals and acids and may involve hydrochloric, sulfuric, perchloric, hydrofluoric, formic, and alternative acids. The individual anodic reactions for iron, nickel, and aluminum are listed as follows (Torabi and Ahmadi, 2020): Iron anodic reaction: FeðsÞ-Fe21 1 2e2 Nickel anodic reaction: NiðsÞ-Ni21 1 2e2 Aluminum anodic reaction: AlðsÞ-Al31 1 3e2 The general anodic reaction occurring throughout corrosion can be written as: General anodic reaction: MðsÞ-Mn1 1 ne2 That is, the corrosion of metal “M” leads to the chemical reaction of metal “M” to an ion with a valence charge of n 1 and therefore the release of “n” electrons. The worth of n, of course, depends totally on the character of the metal. Some metals, like silver, are univalent, whereas multivalent iron, titanium, and uranium possess positive charges as high as 16. This equation is a general one and it applies to any or all corrosion reactions. If the current generated by one of the anodic reactions expressed earlier was familiar, it’d be attainable to convert this current to a similar mass loss or corrosion penetration rate using a helpful relation discovered by Michael Faraday. Faraday’s empirical laws of electrolysis relate the current of an electrochemical reaction to the quantity of moles of the element being reacted. Faraday’s laws of electrolysis, in chemistry, are two quantitative laws used to express magnitudes of electrolytic effects, first described by the English scientist Michael Faraday in 1833. The laws state that (1) the amount of chemical change produced by current at an electrode-electrolyte boundary is proportional to the quantity of electricity used, and (2) the amounts of chemical changes produced by the same quantity of electricity in different substances are proportional to their equivalent weights (Torabi and Ahmadi, 2020). In electrolytic reactions, the equivalent weight of a substance is the formula weight in grams associated with a gain or loss of an electron. (In substances with valences of two or more, the formula weight is divided by the valence.) The quantity of electricity that will cause a chemical change of one equivalent weight unit has been designated a faraday (F). It is equal to 96,485.3321233 coulombs of electricity. Thus, in the electrolysis of fused magnesium chloride, MgCl2, one faraday of electricity will deposit 24.305/2 g of magnesium at the negative electrode (since magnesium has an atomic weight of 24.305 and a valence of 2, meaning that it can gain two electrons) and liberate 35.453 g of chlorine (since chlorine has an atomic weight of 35.453) at the positive electrode. Supposing that the charge needed for such a reaction was one electron per molecule, as is the case for the plating or the corrosion attack of silver, it can be shown as: Ag1 1 e2 -AgðsÞ AgðsÞ-Ag1 1 e2 Uniting Faraday’s main beliefs with specific electrochemical reactions of acknowledged stoichiometry give rise to the following equation:





Q 5 F ΔN n

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Q5

ðt



I dt 0

(10.9)

where N is the number of moles, ΔN is the change in that quantity, n is the number of electrons per molecule of the species being reacted, I is the total current in amperes (A), and t is the period of the electrochemical method in seconds (s). When hydrogen (H) ions are reduced to their atomic type, they typically mix, as shown earlier, to provide hydrogen gas through a reaction with electrons at a cathodic surface. This reduction of hydrogen ions at a cathodic surface can disturb the balance between the acidic hydrogen (H 1 ) ions and the base-forming hydroxyl (OH
) ions, making the solution less acidic, or more alkaline or basic in this region. In neutral water, the anodic corrosion of some metals, such as aluminum (Al), zinc (Zn), or magnesium (Mg), creates enough energy to separate water directly, as illustrated within the following equation and Fig. 10.20. Water splitting cathodic reaction: 2H2 OðlÞ 1 2e2 -H2 1 2OH2 The change in the concentration of H ions, or the increase in hydroxyl (OH) ions, may be shown by testing pH levels to find surfaces on which cathodic reactions are taking place. There can be many cathodic reactions encountered throughout the corrosion process. They include the following: ðacid solutionsÞ O2 1 4H1 1 4e2 -2H2 O ðneutral or basic solutionsÞ O2 1 2H2 O 1 4e2 -4OH2 Hydrogen evolution: 2H1 1 2e2 -H2 ðgÞ Metal ion reduction: Fe31 1 e2 -Fe21 Metal deposition: Cu21 1 2e2 -CuðsÞ Oxygen reduction is a common cathodic reaction because oxygen exists within the atmosphere and in solutions exposed to the environment. Although not frequent, metal ion reduction and metal deposition will cause severe corrosion problems, for instance: the plating of copper ions, which are created upstream in a water circuit, on the inner aluminum surface of a radiator. Therefore, the use of a copper conduit in a water-based circuit where aluminum is also present should generally be avoided. All corrosion reactions are merely combinations of one or many of the above cathodic reactions in conjunction with an anodic reaction. Thus, each case of liquid corrosion may be reduced to those equations in most cases, either on an individual basis or in combination. Take into account the corrosion of Zn (zinc) by water or wet air. By multiplying the Zn oxidization reaction by 2 and summing this with the oxygen reduction reaction, one obtains the following equation: 2ZnðsÞ-2Zn21 1 4e2 ðoxidationÞ 1 O2 1 2H2 O 1 4e2 -4OH2 ðreductionÞ   2Zn 1 2H2 O 1 O2 -2Zn21 1 4OH2 -2ZnðOHÞ2 p The products of this reaction are Zn21 and OH2, which at once react to make insoluble Zn(OH)2. Likewise, the corrosion of Zn by copper sulfate represented within the following

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FIGURE 10.20 Electrochemical reactions of Mg during corrosion in neutral water.

2+

Mg

e–

O

O

H

H H

H e–

H2 H

O

H H

Magnesium equation is simply the summation of the oxidization reaction for Zn and the metal deposition reaction involving copper (II) ions: ZnðsÞ-Zn21 1 2e2 ðoxidationÞ 1 Cu21 1 2e2 -CuðsÞðreductionÞ   Zn 1 Cu21 -Zn21 1 Cu p During corrosion, more than one oxidation and one reduction reaction might take place. In the corrosion of Zn in a concentrated HCL solution containing dissolved oxygen, for example, two cathodic reactions are possible. One is an evolution of H, while the other is the reduction of oxygen. Because there are two cathodic reactions or methods that consume electrons, the general corrosion rate of zinc is overstated. Thus, it is typically more corrosive than air-free acids, and removing oxygen from acid solutions can typically make these solutions less corrosive. This is a typical method for reducing corrosivity in many settings. Oxygen can be removed by either chemical or mechanical means. In corroding a piece of metal, the electrons created at anodic areas flow through the metal to react at cathodic areas that are equally exposed to the environment where they restore the electrical balance of the system. The very fact that there is no net accumulation of charges on a corrosion surface is vital for understanding most corrosion processes and ways to mitigate them. However, the equality between the anodic and cathodic currents expressed within the following equation doesn’t mean that the current densities for these currents are equal:

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I anodic 5 I cathodic By taking the relative anodic (Sa) and cathodic (Sc) surface areas (and their associated current densities ia and ic expressed in units of mA/cm2), this equation can be expressed in terms of current densities. I anodic 5 ia 3 Sa 5 I cathodic 5 ic 3 Sc Sc ia 5 ic Sa

(10.10)

The importance of the surface area ratio (Sc/Sa) of the above equation is notably vital when it comes to several varieties of localized corrosion, such as pitting and stresscorrosion cracking (SCC). Localized corrosion refers to the hastened attack of passive metals in corrosive environments. It is characterized by an intense attack at confined areas on surface components, while the remaining area of the surface corrodes at a much slower rate. This can be due to environmental effects or the component material’s inherent properties, like in the creation of protective film oxide.

10.4 Types of corrosion Corrosion is characterized by many types, depending on its source and nature. Following are some of the principal types: • • • • • • • •

Atmospheric corrosion Erosion corrosion Selective corrosion Uniform corrosion Pitting corrosion Fretting corrosion Stress corrosion Intergranular corrosion In the following section, some of these types are elaborated.

10.4.1 Atmospheric corrosion Atmospheric corrosion is defined as the corrosion of material exposed to ambient conditions. Such corrosion may be intensified in the presence of pollutants or moisture, along with varying temperature conditions. This type of corrosion is one of the oldest forms of corrosion identified. Note that the two most important components in nature that induce corrosion are air and water. This is because every ore had previously attained its natural state through exposure to water and air as part of the natural evolution process. Atmospheric corrosion of engineering structures such as buildings and bridges is strongly dependent upon exposure conditions. Atmospheric corrosion tests have been conducted over many years to make long-term predictions. These tests have shown that corrosion rates of engineering steels are lower in low-humidity rural environments and increase

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in high-humidity marine environments. Corrosion of steel pilings is many times faster in tidal splash zones compared to marine atmospheres (i.e., out of water and several hundred feet inland from shore) or continuously immersed conditions. The atmospheric corrosion rate of carbon steel is determined by the relative humidity (RH), pH, and pollutants in the environment. Similar to most metals, iron, and steel have been reported to have a primary critical RH of B60%, above which a liquid film formed by several monolayers of water develops on the surface. Above this threshold, corrosion governed by electrochemical laws proceeds at a slow rate. At 75%
80% RH, the corrosion rate sharply increases. This secondary critical RH has been attributed to capillary condensation of water in the pores of the iron corrosion products. The deposition of hygroscopic salts on the metal surface can decrease the critical RH and increase the corrosiveness of the electrolyte. In aerated environments, the corrosion rate of carbon steel is controlled by the reduction of oxygen. Depending on the proportions of these two components in nature, atmospheric corrosion is further categorized as: 10.4.1.1 Dry corrosion In the absence of moisture, most metals corrode very slowly at ambient temperatures, which trigger varying degree of oxidation. Note that oxidation is a continuous process, irrespective of the prevalent temperature. The reaction rate follows the Arrhenius equation: 2Ea

k 5 Ae RT

(10.11)

where k 5 rate constant, A 5 preexponential factor, Ea 5 activation energy (in the same units as R*T), R 5 universal gas constant, T 5 absolute temperature (in Kelvin). Dry corrosion at ambient temperature occurs on metals that are in an unstable state. Such an unstable state arises from many steps of denaturing involved in mineral processing. While the effects of such denaturing on the environment are studied and reported (Plant et al., 2014), they are rarely correlated with corrosion. The corrosion product (oxide of metal) is defect free, nonporous, and self-healing and acts as a protective barrier to further corrosive attack of the base metal. Among others, electric resistivity is increased drastically when oxides are formed. For instance, iron metal has much lower electrical resistivity (96.1 nΩ m) than that of Fe3O4 (0.3 mΩ m) and even lower than that of Fe2O3 (approx kΩ m) (Itai, 1971). Metals such as stainless steel, titanium, and chromium develop this type of protective film. However, when iron oxidizes, it produces a characteristic reddish-brown coating that doesn’t securely stick to the metal’s surface. Instead, it peels off and weakens the metal, leaving it vulnerable to further rust and decay. Copper oxidation, on the other hand, creates a decorative patina coat that prevents further exposure to oxygen and curbs corrosion. Table 10.12 shows some of these features of various metals. Usually, porous and nonadhering films that form spontaneously on metals such as unalloyed steel are not desirable. Tarnishing of copper and silver in dry air with traces of hydrogen sulfide (H2S) is an example of a nondesirable film formation at ambient temperatures caused by lattice diffusion. Lattice diffusion refers to atomic diffusion within a crystalline lattice. Diffusion within the crystal lattice occurs by either interstitial or substitutional mechanisms. In interstitial lattice diffusion, a diffusant (such as C in an iron alloy), will diffuse in between the lattice structure of another crystalline element (Khanna and Sahajwalla, 2014). In

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TABLE 10.12 Reaction of various metals (Website 11).

substitutional lattice diffusion (such as allotrope iron), the atom can only move by substituting place with another atom. Substitutional lattice diffusion is often contingent upon the availability of point vacancies throughout the crystal lattice. Diffusing particles migrate from point vacancy to point vacancy by the rapid, essentially random jumping about (jump diffusion). Since the prevalence of point vacancies increases in accordance with the Arrhenius equation, the rate of crystal solid state diffusion increases with temperature. Sulfur dioxide originates predominantly from the burning of coal, oil, and gasoline. In New York City in the 1950s, it was estimated that about 1.5 million tons of sulfur dioxide were produced every year from burning coal and oil. Since fuel consumption is higher in winter, sulfur dioxide contamination is also higher. Fig. 10.21 shows the variation of SO2 during various months (Fig. 10.21). It is also obvious from this cause that the average sulfur dioxide content of the air (and corresponding corrosivity) falls off with distance from the center of an industrial city, and it is clear that this effect is not as pronounced in the case of a residential city, such as Washington, D.C. (Table 10.13). The role of contaminants, such as sulfur impurities, is akin to that played by catalysts. They are essential but do not form any appreciable fraction of the overall composition. Any presence, sulfide increases the likelihood of defects in the oxide-lattice and thus destroys the protective nature of the natural film, which leads to a tarnished surface. Damp corrosion requires moisture in the atmosphere and increases aggressiveness with the moisture content. When the humidity exceeds a critical value, which is around 70%
75% relative humidity, an invisible thin film of moisture will form on the surface of the metal, providing an electrolyte for current transfer, The critical value depends on surface conditions such as cleanliness, corrosion product buildup, or the presence of salts or other

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FIGURE 10.21 Variation of average sulfur dioxide content of New York City air with time of year. Source: Modified from Revie and Uhlig (2008).

SO2 Content, ppm

0.3

0.2

0.1

0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct. Nov Dec

Month of year

TABLE 10.13

Variation of SO2 content of air with distance from center of city (Revie and Uhlig, 2008). Parts per million 0
5 0
8

5
10 8
16

10
15 16
24

15
20 24
32

20
25 32
40

25
30 40
48

Detroit

0.023

0.012

0.006

0.004

0.004

0.005

Philadelphia-Camden

0.030

0.018

0.016

0.021

0.012

0.012

Pittsburgh

0.060

0.030

0.015

0.018

0.009

0.010

St. Louis

0.111

0.048

0.029

0.020

0.018

0.014

Washington, D.C.

0.003

0.001

0.001

0.001

0.001

0.002

City

Distance miles Kilometers

contaminants that are hygroscopic and can absorb water at lower relative humidities. The precondition, however, is that a complete lubricating film develops. If dampening is not sufficient or if there is only a small amount of water, the friction can even be increased in the first instance, as shown in Fig. 10.22. Thus, even ambient humidity considerably contributes to the development of stick-slip. During one experiment, with increasing ambient humidity an adhesion peak will already develop at 30% relative humidity at 23 C (Fig. 10.22), and at 60% relative humidity stick-slip develops. At about 75% relative humidity, the developing lubricating film reduces adhesion and thus the friction force and the friction instabilities that are dominant up to that point. The resultant potential difference causes a current to flow and considerable corrosion can result. Corrosion is most severe when the resistance of the electrolyte is low, for example, in seawater. In some cases, surface moisture films resulting from aggressive atmospheres can give rise to galvanic corrosion. In practice, copper, brasses, and bronzes in marine conditions cause the most galvanic corrosion problems. The corrosion potentials for a range of metals based on measurements made according to ASTM G69
97 (2009) are shown in Table 10.14. Comparison of measured corrosion potentials in 1 M NaCl containing 9 6 1 g/L H2O2.

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2.5 constant terms rising humidity rising temperature

friction force [N]

2

adhesive force increasing

start stick-slip

1.5

stop stick-slip, adhesive force decreasing

1

0.5

23ºC / 50 %

23ºC / 50 %

23ºC / 0 %

23ºC / 80 %

0ºC / 5 %

80ºC / 5 %

0 0

FIGURE 10.22

20

40

60

80 time [min]

100

120

140

Influence of humidity and temperature on the friction behavior (Stoll and Strangfeld, 2012).

TABLE 10.14 Corrosion potential for various metals (Birbilis and Hinton, 2011). Material

Corrosion potential (VSCE)

Al (99.999)

20.75

Cu (99.999)

10.00

Fe

20.55

Mg

21.64

Zn

20.99

1100

20.74

2014-T6

20.69

2024-T3

20.60

3003

20.74

5052

20.76

5154

20.77

6061-T4

20.71

6061-T6

20.74

6063

20.74 (Continued)

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TABLE 10.14

(Continued)

Material

Corrosion potential (VSCE)

7039-T6

20.84

7055-T77

20.75

7075-T6

20.74

7075-T7

20.75

7079-T6

2 0.78

8090-T7

20.75

Where noble metals contained in intermetallic particles are present in the microstructure of aluminum alloys, they may exhibit different behavior to aluminum. The surface of copper is particularly efficient at supporting cathodic reactions (e.g., water reduction). Given that the majority of other engineering metals display potentials that are considerably more noble than those of aluminum, bimetallic corrosion of aluminum is a frequent cause of service-related corrosion failure. The rate of such attack can be rapid and corrosion can be severe. Engineering solutions are generally simple and involve providing sufficient protection using combinations of paints and physical barriers to ensure that either electrical or electrolytic continuity is broken. Contact with steel can accelerate attack on aluminum. Titanium may behave in a similar manner to steel. This is due to Volta potential (also called Volta potential difference, contact potential difference), which is the electrostatic potential difference between two metals (or one metal and one electrolyte) that are in contact and are in thermodynamic equilibrium. Stainless steel in contact with aluminum may increase attack on aluminum rather significantly in a moist environment. If passivated, the high electrical resistance of the surface oxide film on stainless steels minimizes bimetallic effects in less aggressive environments. Passivation is an acid-based chemical treatment used on stainless steel to increase the thickness and protective capability of the naturally occurring passive film. 10.4.1.2 Wet corrosion Wet corrosion occurs when water pockets or visible water layers are formed on the metal surfaces because of sea spray, rain, or drops of dew. Crevices or condensation traps also promote the pooling of water and lead to wet atmospheric corrosion even when the flat surfaces of a metal component appear to be dry. During wet corrosion, the solubility of corrosion product can affect the corrosion rate. Typically, when the corrosion product is soluble, the corrosion rate will increase. This occurs because the dissolved ions normally increase the conductivity of the electrolyte and thus decrease the internal resistance to current flow, which will lead to an increased corrosion rate. The general corrosion rates from the different probes are presented in Fig. 10.23 (Sun et al., 2021). The general corrosion rate was calculated using the average anodic current density, which is the total anodic current from all the electrodes of the probe divided by the total surface areas of all the electrodes of the probe. Because this average corrosion

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FIGURE

1E+3

General corr rate (Pm/year)

S. Steel

CP potential insufficient

Brass C. Steel 1E+1 Without CP

10.23 General corrosion rates from the three CMAS probes in drinking water before and after they were connected to their sacrificial CP anodes (Sun et al., 2021).

With CP

1E-1

CP potential sufficient 1E-3 16:26

17:13

18:00

18:46

19:33

Time (h:min)

rate is similar to the general corrosion rate obtained by weight loss methods or by other electrochemical methods using large electrodes, the use of the average corrosion rate to approximate the general corrosion rate is a reasonable approach. Compared with Fig. 10.23, the average/general corrosion rates from these three metals have similar trends with the maximum localized corrosion rates, but the values are much smaller. The maximum localized corrosion rates were 7.5
8 times higher than their general corrosion rates for the Type 260 brass and low carbon steel during the test. The ratio of the maximum localized corrosion rate to the general corrosion rate for the Type 316L stainless steel was approximately 9 at the end of the test. These ratios are also called localized corrosion rate factors. Under alternating wet and dry conditions, the formation of an insoluble corrosion product on the surface is likely to increase the corrosion rate during the dry cycle by absorbing moisture and continually wetting the surface of the metal. The role of alternative wet and dry conditions intensifies when other mitigating factors prevail. For instance, Gong et al. (2020) studied SCC behavior of X100 steel under alternating dry/wet conditions through electrochemical experiments and slow strain-rate testing. The results show that the corrosion morphology transforms from general corrosion to pitting with an increasing dry/wet ratio (D/W). The corrosion product layer becomes less protective with decreasing pH, which leads to pitting and shows that anodic dissolution is promoted. In addition, local acidification under the corrosion product layer promotes the hydrogen evolution reaction. They concluded that the SCC mechanism of X100 steel under alternating dry/wet conditions at low pH and a high D/W ratio involves anodic dissolution and hydrogen evolution. The corrosion current density of X100 steel at different solution pH and D/W ratios is shown in Fig. 10.24. The corrosion current density gradually decreases with increasing

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FIGURE 10.24 Corrosion current densities (Icorr) as functions of pH under alternating dry/wet conditions at various D/W ratios (Gong et al., 2020).

pH, and this decrease was large when the pH was increased from 4 to 6. In addition, at the same pH, different D/W ratios significantly affect the corrosion current density, which gradually increases with increasing the D/W ratio.

10.4.2 Stress corrosion SCC is a well-known for causing corrosion, leading to underground oil and gas transmission pipeline failures. SCC of cathodically protected pipelines originates on the outer pipe surface, most commonly at areas where the coating is disbonded (i.e., no longer attached to the surface of the steel pipe). Although SCC is always used in relation to corrosion, the connection is not direct. Precorrosion followed by loading in an inert environment will not result in any significant crack propagation, while simultaneous environmental exposure and application of stress will cause time-dependent subcritical crack propagation. Stress triggers the onset of corrosion while corrosion triggers propagation of cracks. The process is best described as synergy between interaction of mechanical and chemical forces resulting in crack onset and propagation, whereas neither factor acting independently or alternately would result in the same effect. The stresses required to cause SCC are small, usually below the macroscopic yield stress, and are tensile in nature. The stresses can be externally applied, but residual stresses often cause SCC failures. However, compressive residual stresses can be used to prevent this phenomenon. Static loading is usually considered to be responsible for SCC, while environmentally induced crack propagation due to cyclic loading is defined as corrosion fatigue. The boundary between these two classes of phenomena is vague, and corrosion fatigue is often considered to be a subset of SCC. However, because the environments that cause corrosion fatigue and SCC are not always the same, these two should be considered separate phenomena. Environments that cause SCC are usually aqueous and can be either condensed layers of moisture or bulk solutions. SCC is the result of a specific chemical species in the environment. For example, the SCC of copper alloys, traditionally referred to as season cracking, is usually due to the presence of ammonia in the environment, and chloride ions cause or exacerbate cracking in stainless steels and aluminum alloys. Also, an environment that causes SCC in one alloy may not cause it in another. Changing the temperature, the degree of aeration, and/or

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the concentration of ionic species may change an innocuous environment into one that causes SCC failure. Also, different heat treatments may make the same alloy either immune or susceptible. As a result, the list of possible alloy/environment combinations that cause SCC is continually expanding, and the possibilities are virtually infinite. Some of the more commonly observed alloy/environment combinations that result in SCC are listed in Table 1.1. In general, SCC is observed in alloy/environment combinations that result in the formation of a film on the metal surface. In many cases, these films reduce the rate of general or uniform corrosion, making the alloy desirable for resistance to uniform corrosion in the environment. As a result, SCC is of greatest concern in corrosion-resistant alloys exposed to aggressive aqueous environments. Table 10.15 lists several alloy/environment combinations and the films that may form at the crack tip (Table 10.16). SCC is a delayed failure process. That is, cracks initiate and propagate at stresses in the remaining ligament of metal that exceeds the fracture strength. The sequence of events involved in the SCC process is usually divided into three stages: • Stage 1 propagation and crack initiation • Stage 2 or steady-state crack propagation • Stage 3 crack propagation or final failure The characteristics of each of these stages are subsequently discussed in greater detail. First, however, the techniques used to measure SCC are reviewed briefly. Fig. 10.25 shows these phases, along with surface cracking, spalling, and eventually structural collapse either due to loss of anchorage or reinforcement rupture. Metal spalling is a process of metallic surface failure in which the metal is broken down into small flakes (spalls) from a larger solid body. This process occurs for many reasons, such as when another material impacts it at a high speed resulting in chipping the material, or due to corrosion, weathering, cavitation, or excessive rolling pressure. In the metal spalling process, spontaneous fragmentation, chipping, or separation of a surface, or surface coating occurs. The most favorable location for metal spalling to occur in industrial equipment is either at the lowest point of the equipment or at the metal joints TABLE 10.15 Alloy/environment systems exhibiting stress-corrosion cracking (Jones and Ricker, 2017). Alloy

Environment

Carbon steel

Hot nitrate, hydroxide, and carbonate/bicarbonate solutions

High-strength steels

Aqueous electrolytes, particularly when containing H2S

Austenitic stainless steels

Hot, concentrated chloride solutions; chloride-contaminated steam

High-nickel alloys α brass

High-purity steam Ammoniacal solutions

Aluminum alloys

Aqueous CI2, Br2, and I2 solutions

Titanium alloys

Aqueous Cl2, Br2, and I2 solutions; organic liquids; N2O4

Magnesium alloys

Aqueous Cl2 solutions

Zirconium alloys

Aqueous Cl2 solutions; organic liquids; I2 at 350 C (660 F)

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TABLE 10.16 Ricker, 2017).

Alloy/environment combinations and the resulting films that form at the crack tip (Jones and

Metal or alloy

Environment

Initiation layer

α brass, copper
aluminum

Ammonia

Dealloyed layer (Cu)

Gold
copper

FeCl3

Dealloyed layer (Au)

Acid sulfate

Dealloyed layer (Au)

Chloride

Dealloyed layer (Au)

Hydroxide

Dealloyed layer or oxide

High-temperature water

Dealloyed layer or oxide

α brass

Nitrite

Oxide

Copper

Nitrite

Oxide

Ammonia (cupric)

Porous dissolution zone

High-temperature water

Oxide

Phosphate

Oxide (?)

Anhydrated ammonia

Nitride

CO/CO2/H2O

Carbide

CS2/H2O

Carbide

Titanium alloys

Chloride

Hydride

Aluminum alloys, steels

Various media

Near-surface hydrogen

Iron
chromium
nickel

Ferritic steel

FIGURE 10.25 Corrosion-induced cracking: service life definition after Tuutti (Fahy et al., 2017).

deterioration collapse propagation

initiation

Phase III Phase I

Phase II spalling

depassivation

surface cracks exposure time

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or crevices where the stresses are high and maximum shearing of the material occurs during the operation of the equipment. A simple form of mechanical spalling occurs when two metal plates collide with each other and produce metal shock waves (also known as compression waves) that are reflected back on the respective metal plates. These compression waves are further reflected in the regions where high tensile stresses are acting and cause further damage and failure. Metal spalling is also caused by cavitation, when fluid at a low pressure causes a formation of vapor bubbles. A localized high-pressure area is created when these vapor bubbles collapse that causes spalling on adjacent or nearby surfaces. Also, if a metallic surface is already corroded, it results in spalling as small flakes of the metal are chipped away, which further exposes the inner surface of the material to a corrosive environment. Fahy et al. (2017) reported a study focusing on the propagation phase by modeling the transport of corrosion products into the concrete and its influence on the process of corrosion-induced cracking. Corrosion in reinforced concrete involves the transformation of steel reinforcement into corrosion products, which occupy a greater volume than the original steel. The ratio of the volumes of corrosion products and steel can vary from less than two to more than six. As such the process involves continuous stress of varying magnitude, essentially arising from the volume expansion in internal pressure acting on the concrete, which is equilibrated by circumferential tensile stresses leading to cracks in and potentially spalling of the concrete. Understanding corrosion-induced cracking in concrete is difficult because of multiple interacting processes and phenomena, such as the transport of corrosion products into pores and cracks, the spatial distribution of steel areas affected by corrosion, compaction of corrosion products, the influence of the chemical environment on the rust products, and creep, shrinkage, hardening and cracking of concrete. The process of corrosion-induced cracking involves strong coupling between the electrochemical process of the generation of corrosion products (modeled as a fluid in this work) and their structural confinement by the surrounding concrete. The build-up of fluid pressure due to this coupling results in the transport of corrosion products into pores and cracks in the concrete, which must be considered when predicting corrosion-induced cracking in reinforced concrete structures, since this transport significantly delays the onset of cracking. SCC in a buried pipeline is the result of interaction between a corrosive environment and stress on the surface of line pipe to form a crack or cracks at the surface that may eventually propagate through the pipe wall. SCC requires the combination of an aggressive environment, sufficient stress, and a susceptible material. When all conditions are met, there is an onset of a crack that then propagates progressively over time and can reach lengths sufficient for catastrophic failure. Two types of SCC have been identified in pipeline steels (James and Hudgins, 2016): 1. Intergranular (high pH) SCC 2. Transgranular (near-neutral pH) SCC The first recognized SCC failure in oil and gas pipelines was in Natchitoches, Louisiana, USA, in 1965 as a result of high-pH SCC (pH 9
11) (James and Hudgins, 2016). Before that incident, SCC on buried pipelines was previously unknown; multiple agencies and organizations performed extensive examinations before the Natchitoches failure attributed to SCC.

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Another gas transmission pipeline failure was attributed to SCC in 1966. Initially, incidents identified as SCC were limited to gas transmission pipelines installed in heavy clay soils along the US Gulf Coast. Subsequent industry experience has revealed that SCC can occur in a variety of soils and climates on any continent with a significant pipeline network. Until recently, more pipeline failures involving SCC were reported for natural gas pipelines than for hazardous liquid pipelines. In 2003, three failures involving hazardous liquid pipelines were attributed to SCC. In addition, subsequent assessments of other hazardous liquid pipelines have revealed indications of SCC not previously identified. SCC of buried pipelines is one of several identified integrity threats for pipeline systems. The Pipeline and Hazardous Materials Safety Administration, formerly Research and Special Programs Administration (RSPA), Office of Pipeline Safety (OPS) commissioned a review of the pipeline industry’s experience with SCC to establish a baseline of the collective knowledge and best practices to successfully manage the SCC threat. Between 2010 and 2013, there were 375 onshore gas transmission pipeline incidents. The most common causes for onshore gas transmission pipeline incidents were corrosion, material failure of pipe or welds, and equipment failure. Incidents attributed to corrosion and material failure of pipe or weld alone resulted in 8 fatalities, 51 injuries, and more than $466 million of estimated total costs to operators (NEB, 1996). Furthermore, within the past 6 years, the National Transportation Safety Board (NTSB) has investigated three gas transmission pipeline incidents in which issues related to operators’ Integrity Management programs and PHMSA’s oversight were of concern (NTSB 2011, 2013, 2014). Much of the industry’s emphasis has been placed on the use of integrity assessment methods in detecting defects that may lead to failure causes such as corrosion and material failure. However, the general IM principle calls for the reduction of risk associated with all threats, including corrosion, manufacturing defects, equipment failures, third-party damage, and incorrect operations. The environment causing SCC typically includes a relatively small volume of fluid trapped between a disbonded coating and the pipe surface. Groundwater composition influences the environment causing SCC, but the chemical composition of the trapped fluid may be altered by the interaction of cathodic protection with the fluid and the pipe surface. Earlier examples of SCC, which is commonly called “classic” or high-pH SCC, were associated with water containing carbonates and bicarbonates at a pH of approximately 9
11. Another type of SCC, which is commonly called low pH or, more appropriately, near-neutral pH SCC, has been associated with water containing dissolved carbon dioxide (CO2) at a pH of about 6
8 (Fig. 10.26). Table 10.17 summarizes the characteristics of the two types of SCC in buried pipelines. Two known forms of SCC cause failures on pipelines: high pH or “classical” and low pH or “near-neutral pH,” each case triggering electrochemical changes in the system. Corrosive reaction is a transitional and continuous condition. As stipulated in the Arrhenius equation, two main parameters are free activation energy and temperature. Both parameters form a formula expressing the reaction constant, kcorr, otherwise known as the Arrhenius constant. Activation free-energy is a barrier-energy between the alloy

Pipelines

766

FIGURE 10.26

10. Corrosion and its mitigation

Stress-corrosion cracking colony on a large-diameter, high-pressure transmission gas pipeline

(Website 13).

TABLE 10.17 Summary of stress-corrosion cracking in buried pipelines. Factor

Near-neutral pH SCC

High-pH SCC (Classical)

Location

• Associated with specific terrain conditions, often alternate wet-dry soils, and soils that tend to disbond or damage coatings

• Typically within 20 km downstream of pump or compressor station • Number of failures falls markedly with increased distance from compressor/ pump and lower pipe temperature • Growth rate increases exponentially with temperature increase

• No apparent correlation with temperature of pipe • May occur more frequently in the colder climates where CO2 concentration in groundwater is higher Associated • Dilute bicarbonate solution with a neutral pH • Concentrated carbonate
bicarbonate electrolyte in the range of 5.5
7.5 solution with an alkaline pH greater than 9.3 • 2 600 to 2750 mV (Cu/CuSO4) Electrochemical • 2 760 to 2790 mV (Cu/CuSO4) • Cathodic protection does not reach pipe • Cathodic protection contributes to potential surface at SCC sites achieving these potentials • Primarily intergranular (between the steel Crack path and • Primarily transgranular (across the steel grains) morphology grains) • Narrow tight cracks with almost no • Wide cracks with evidence of substantial evidence of secondary corrosion of crack corrosion of crack side wall wall Temperature

From NEB (1996) and CEPA (1997).

and its corrosion product. In this system, corrosion occurs whenever free-energy is available as the potential to generate the flow of electric current between anode and cathode. Environmentally assisted cracking, such as SCC in buried pipelines, requires the presence of at least a minimum level of stress to promote cracking. This minimum stress level is labeled as the “threshold stress.” This threshold is surpassed under the combined influence of tensile stress and a corrosive environment. The impact of SCC on a material

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10.4 Types of corrosion

767

usually falls between dry cracking and the fatigue threshold of that material. The required tensile stresses may be in the form of directly applied stresses or in the form of residual stresses. The problem itself can be quite complex. The situation with buried pipelines is a good example of such complexity. The total stress that can contribute to SCC in pipelines include the stress applied by pressure, residual stresses from line pipe manufacture and installation, and stresses imposed by external forces such as soil movement. Increments of stress above the threshold stress may reduce the time to initiate first cracks and increase the rate of crack growth. SCC is most often found in clusters of parallel cracks called colonies or families. A cluster of SCC may contain relatively few to hundreds of cracks. Cracks are most often longitudinal, but circumferential cracks have occurred as a result of longitudinal or bending stresses. The most obvious identifying characteristic of SCC in pipelines, regardless of pH, is the appearance of patches or colonies of parallel cracks on the external surface of the pipe. There may be several of these colonies on a single joint of pipe and many joints of pipe may be involved. The cracks are closely spaced and of varying length and depth. These cracks frequently coalesce to form larger and longer cracks, which in some cases can lead to rupture. If the cracks are sparsely spaced, they might grow through the wall and leak, before they reach a length that is sufficient to cause a rupture. In order for SCC to occur, three conditions must be satisfied simultaneously. They are listed below and in Fig. 10.27: 1. A tensile stress higher than the threshold stress, frequently including some dynamic or cyclic component to the stress; 2. A material that is susceptible to SCC; 3. A potent cracking environment. SCC cracking is usually oriented longitudinally in response to the hoop stress of the pipe, which is usually the dominant stress component resulting from the internal pressure. However, in some cases (reported as 10%
20% in Canada), SCC also occurs in the circumferential direction (C-SCC) when the predominant stress is axial stress, such as stresses developed in response to pipe resistance of soil movement, at a field bend, or due to the residual welding stresses at a girth weld (CEPA, 1997).

FIGURE 10.27 Environment

Metallurgy

cracking.

Stress

Pipelines

Three conditions necessary for stress-corrosion

768

10. Corrosion and its mitigation

FIGURE 10.28 Example of the colony of stress-corrosion cracks on the external surface of the high-pressure gas transmission pipeline.

Individual cracks are typically semielliptical. Initiation and growth of SCC cause the concentration of stresses near the crack tips. Stresses concentrated near the crack tips can cause cracks to extend or grow both through the wall and along the surface. Growth of individual cracks in a cluster can lead to interaction of stresses at crack tips that are generally aligned and relatively close. Cracks that interact may link to form longer cracks. Typically, SCC colonies are initiated at the external surface sites where there is already pitting or general corrosion (Fig. 10.28). The solution termed NS4 was developed to simulate SCC environments and it became the favored standard environment for crack propagation testing in most laboratories. The peculiarity of our research was the use of NS4 solution (purged with CO2 only) with a lower pH (pH5.7) instead of standard NS4 solution in order to estimate the impact of acid soils on SCC of the pipeline steels (Zvirko et al., 2016). Zvirko et al. (2016) developed a procedure for the accelerated degradation, consisting in consistently subjecting the steel specimens to electrolytic hydrogen charging, axial loading up, and artificial aging. The procedure was proved to be reliable for laboratory simulation of in-service degradation of pipeline steels of different strengths. The results of the SSRT carried out on the in-laboratory degraded 17H1S and X60 pipeline steels to evaluate the SCC susceptibility demonstrated that specimens tested in the NS4 solution saturated with CO2 under open circuit potential (OCP) and room temperature presented susceptibility to SCC, reflected in the degradation of mechanical properties, whereas high resistance of the as-received pipeline steels to SCC was detected. The degraded X60 steel showed higher resistance to SCC in comparison with the degraded 17H1S steel. Fractographic observation confirmed that hydrogen embrittlement of pipeline steels was caused by permeated hydrogen inside them. They determined the susceptibility of the 17H1S and X60 pipeline steels to SCC was studied by the SSRT for the as-received and degraded specimens. Average results obtained by tensile tests carried out on studied steels specimens in NS4 test solution saturated with CO2 under OCP and in air as a reference are illustrated in Table 10.18. Mechanical properties such as ultimate stress σUTS, and yield strength σY, reduction in area RA, and elongation were calculated from the stress versus strain curves. According to the data obtained by the SSRT no susceptibility of the 17H1S pipeline steel in the as-received state to SCC in NS4 test solution, saturated CO2 was revealed.

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10.4 Types of corrosion

TABLE 10.18

Medium

Ultimate strength σUTS, MPa

Yield strength σY, MPa

Reduction in area RA, %

Elongation, %

Asreceived

air

470

301

65.9

21.2

Asreceived

NS4 saturated with CO2

473

304

66.1

21.1

Degraded NS4 saturated with CO2

467

426

46.4

10.9

Asreceived

air

592

510

81.9

23.2

Asreceived

NS4 saturated with CO2

565

489

77.6

21.9

Degraded NS4 saturated with CO2

610

551

71.3

16.4

Pipeline steel

Steel state

17HlS

X60

Mechanical properties experimentally observed for studied pipeline steels.

Concerning X60 pipeline steel with higher strength it should be noted that it was characterized by very low sensitivity to SCC in this case. Thus, the presence of the corrosive environment slightly facilitates fracture of the X60 steel specimen in comparison with the test in air: reduction in area and elongation insignificantly decrease. Fig. 10.29 shows the SEM images of the fracture surfaces of the as-received 17H1S steel specimen after SSRT in air and the degraded 17H1S steel specimen after SSRT in NS4 solution, saturated with CO2. In general, the fracture mode of the studied material revealed at macro scale is predominantly ductile. The fracture surfaces of the steel specimen tested in air observed with higher resolution of SEM photographs (Fig. 10.29A and B) shows that the fracture occurs by the classic scenario: cup and cone fracture with necking. Thus, crack initiation is most likely to occur in the middle of the steel specimen with the subsequent propagation to the surface, which results in the formation of lateral necking. Fig. 10.29B illustrates the dimpled fracture surface observed in the central part of the steel specimen due to microvoid coalescence, resulting in dimpled rupture. In ferritic grains, the large voids were mainly formed, and within pearlitic grains—small, which were linked to the laminated cementite. The fracture surface of the specimen lateral surface demonstrates the increasing role of shear processes, that cause the appearance of shallower dimples, disclosing the lower permanent strain ability of these areas along the main loading direction. The fracture surfaces of the steel specimen tested in air observed with higher resolution SEM photographs show that the fracture occurs by the classic scenario: cup and cone fracture with necking. Thus, crack initiation is most likely to occur in the middle of the steel specimen with the subsequent propagation to the surface, which results in the formation of lateral necking. Fig. 10.29B illustrates the dimpled fracture surface observed in the central part of the steel specimen due to microvoid coalescence, resulting in dimpled rupture. In ferritic grains, the large voids were mainly formed, and within pearlitic grains—small, which were linked to the laminated cementite. The fracture surface of the specimen lateral surface demonstrates the

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200 Pm

200 Pm

EHT = 15.00 kV WD = 16.5 mm

Signal A = SE1 Photo No. = 6597

Date :3 Feb 2016 Time :14:15:08

EHT = 15.00 kV

Signal A = SE1

WD = 9.5 mm

Photo No. = 6614

Date :3 Feb 2016 Time :14:52:59

FIGURE 10.29

(A)

(B)

SEM images, showing the fracture surfaces of the 17H1S steel specimens in the as-received state (A) and after the accelerated degradation (B), SSRT tested in air (A) and in NS4 solution, saturated with CO2, under open circuit potential (B).

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10.4 Types of corrosion

771

increasing role of shear processes, that cause the appearance of shallower dimples, disclosing the lower permanent strain ability of these areas along the main loading direction. Earlier incidents of classic SCC in gas transmission pipelines were generally located downstream from compressor stations and were associated with coating damage caused by the combination of excessive temperature and soil stresses. As discussed earlier, the SCC typically occurs in alloys, such as stainless steel, and not in pure metals. Corrosion also tends to occur in an environment where stress is applied to the components. As such, screws, metallic paint, etc. are vulnerable points. When the pipeline is in contact with the soil, stretch due to soil movement will lead to sagging and stretching of disbanded paint, thus triggering crack along the top of the pipeline. In addition, soil moisture can infiltrate the gap between pipe walls and the coating, creating ambient pH that is conducive to SCC. Earlier incidents identified as near-neutral pH SCC were generally located under spiralwrap tape coatings. Spiral-wrap tape coating forms “tents” where the tape overlaps the previous wrap or passes over a longitudinal or helical seam in line pipe. Spiral-wrap tape may also “wrinkle” where tape passes over a field bend or other irregular contour. Groundwater that penetrates tape coating at the overlap or damage may accumulate in nearby tents and wrinkles. Asphalt enamel coating can disbond around the circumference of a pipeline while remaining relatively intact. Groundwater accumulating under disbonded tape or asphalt coating may eventually provide an environment conducive to SCC. The circumferential stress in pipelines designed with a maximum allowable operating pressure (MAOP) of 72% of specified minimum yield strength (SMYS) typically exceeds the threshold stress for SCC in buried pipelines. Pipelines designed with an MAOP of 30% of SMYS are not likely to experience SCC unless the external stresses are significant. 10.4.2.1 Conditions that may contribute to stress-corrosion cracking SCC may occur when the environment in contact with a pipe surface promotes SCC and when the combined residual, pressure, and external stresses are above the stress threshold level. Disbonded but relatively intact external coating may also shield the pipe surface from cathodic protection, but current flow through the liquid may elevate the native pH of the groundwater into the cracking range for classic SCC. External pipeline coatings may disbond as a result of application errors, excessive temperature, soil stresses, and the nature of the coating system. The application of external coating over a contaminated pipe surface is an installation error that has contributed to disbonding. Heat from gas compression can cause premature degradation of coal tar and asphalt coatings downstream from compressor stations and can render the coatings more susceptible to soil stresses. Spiral-wrap tape coating may not adhere to the surface adjacent to contour irregularities, such as longitudinal seams and bends. SCC may occur when the environment in contact with a pipe surface promotes SCC and the combined residual pressure and external stresses are above the threshold stress. SCC may become inactive for extended periods when the environment or stresses shift outside the cracking window but can reactivate if conditions return to the cracking window. The effective rate of crack extension is a function of the active growth rate and the proportion of the time that a crack is active. Multiple variables influence the proportion of

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10. Corrosion and its mitigation

time that a crack in a pipeline is active, making estimation of the effective growth rate extremely difficult. Extensive testing of line pipe with and without SCC has attempted to identify physical, chemical, or microstructural attributes, such as manufacturer, vintage, pipe type, grade, wall thickness, actual strength, chemical composition, and rolling practice, that are correlated with susceptibility to SCC. As yet, no cost-effective method to produce line pipe immune to SCC has been identified. 10.4.2.2 Stress-corrosion cracking detection Because not all pipeline segments with disbonded coating have suffered SCC, discrimination of locations with and without SCC is critical to assessing pipeline integrity. While some SCC may be visible to the unaided eye, visual examination alone is insufficient to reliably detect SCC. Both magnetic particle testing (MT) and dye-penetrant testing (PT) will reveal SCC when the pipe surface is properly prepared, but MT may be more cost-effective when electric power to energize a magnetizing yoke is available. MT with the particles suspended in a liquid is more sensitive for the detection of SCC than MT with dry powder, but both methods can be useful. A significant portion of detected classic SCC has been located on the lower third of pipelines. Properly applying magnetic particles to the lower third of a pipeline requires training and practice to develop the necessary skills. Technicians assigned to inspection of pipelines for SCC should be trained on pipe sections containing SCC that were removed from a pipeline and should have demonstrated their ability to detect SCC in all positions. Accommodating the physical needs of inspectors, such as providing sufficient clearance, surface preparation, and pumping water from excavations, is also critical to conducting reliable inspection efforts of the lower portion of a pipeline to detect SCC. Vendors of inline inspection (ILI) services began developing tools for detection of SCC in the early 1970s in response to initial SCC failures. This development has been a challenging and costly endeavor. Reportedly, the ILI tools that use ultrasonic testing in hazardous liquid pipelines in which the transported fluid couples the transducers to the pipe wall are generally satisfactory for detecting SCC. In contrast, operators of gas transmission pipelines that have run ILI tools to detect SCC have stated that the tools do not adequately discriminate between SCC and other imperfections not injurious to pipeline integrity. Excavation of all ILI indications in a gas pipeline for direct examination—to identify a relatively few that are SCC—may be costly. Various nondestructive evaluation (NDE) techniques have been introduced to detect and locate SCC. One commonly used one is dye-penetrant testing. It is a relatively simple method that can be easily performed at remote test sites. However, besides requiring surface preparation, dye penetrant can only detect defects that are open at the sample surface, and it performs poorly on hot, dirty, and rough surfaces as well as on porous materials. Larson (2002) identified over 40 factors that can affect the performance of a penetrant inspection. These factors include variables affected by (1) the formulation of the materials, (2) the inspection methods and techniques, (3) the process control procedures, (4) human factors, and (5) the sample and flaw characteristics. Inspection sensitivity is affected most by surface tension, dye content, and the dimensional threshold of fluorescence. The

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10.4 Types of corrosion

properties of the emulsifier, if required, and the developer have also been shown to have an effect on sensitivity. The inspector is usually not involved with the formulation of the penetrant materials, but understanding the characteristics of a penetrant helps to understand the need to control process variables and not to mix chemicals between penetrant systems. Process variables, such as temperature, are known to have an effect on the surface tension, viscosity, and volatility of a penetrant that will have a somewhat obscure effect on sensitivity. Processing parameters, such as the preparation of the part and the penetrant removal process, have a much more straightforward impact. Finally, there are factors beyond the control of the inspector that can affect the inspection result. These factors include the inspector’s eyesight, the training and knowledge of the inspector, and the nature of the defect to be detected. A summary of the factors identified as having the ability to affect the sensitivity of a liquid penetrant inspection is presented in Table 10.19. TABLE 10.19

Summary of factors that can affect the sensitivity of a liquid penetrant inspection.

Materials

Penetrants

Surface wetting Viscosity Specific gravity Color and fluorescence brightness Dimensional threshold of fluorescence Ultraviolet stability Thermal stability

Emulsifiers

Removability Emulsifier contact time and wash time

Developers

Permeability, porosity, and dispersivity Surface energy Liquid carrier Whiteness

Inspection method/ technique

Preparation of the part

Part cleanliness Metal smear from machining or cleaning Use of etchant Plugging of defects with cleaning media Chemical cleaning process Dryness of parts and defects Previous penetrant inspection Penetrant type (Continued)

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TABLE 10.19 (Continued) Selection of penetrant method/ technique

Sensitivity level Application method Dwell time

Penetrant removal procedure

Emulsifier concentration Emulsifier contact time Rinse method and time

Developer

Use of a developer Type of developer used Application method

Process/quality control

Control of materials

Freshness of materials/tank life Penetrant contamination Emulsifier bath concentration Emulsifier contamination Developer contamination Storage temperature

Control of the procedure

Temperature of the materials Wash temperature and pressure Drying temperature Thickness of developer layer Inspection lighting

Inspection variables

Human factors of inspectors

Visual acuity Color vision Eyewear Training and knowledge of defects Inspectors attitude and motivation Inspection environment

Nature of part and defect

Surface condition of part Complexity of part Defect type Defect dimensions Loading condition of part (closure)

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10.4 Types of corrosion

775

Eddy current and pulsed eddy current techniques can be used for rapid inspection, and have a relatively small probe size, and there is no need to physically contact the test samples. Eddy current testing is one of several nondestructive testing methods that use the electromagnetism principle for flaw detection in conductive materials. A specially designed coil energized with an alternating current is placed in proximity to the test surface, generating a changing magnetic field that interacts with the test-part and produces eddy currents in the vicinity. Variations in the changing phases and magnitude of these eddy currents are then monitored through the use of a receiver coil or by measuring changes to the alternate current flowing in the primary excitation coil. The electrical conductivity variations, the magnetic permeability of the test-part, or the presence of any discontinuities, will cause a change in the eddy current and a corresponding change in phases and amplitude of the measured current. The changes are shown on a screen and are interpreted to identify defects. The process relies upon a material characteristic, namely, electromagnetic induction. When an alternating current is passed through a conductor—a copper coil for example— an alternating magnetic field is developed around the coil and the field expands and contracts as the alternating current rises and falls. If the coil is then brought close to another electrical conductor, the fluctuating magnetic field surrounding the coil permeates the material and, by Lenz’s Law, induces an eddy current to flow in the conductor. This eddy current, in turn, develops its own magnetic field. This “secondary” magnetic field opposes the “primary” magnetic field and thus affects the current and voltage flowing in the coil. Any changes in the conductivity of the material being examined, such as near-surface defects or differences in thickness, will affect the magnitude of the eddy current. This change is detected using either the primary coil or the secondary detector coil, forming the basis of the eddy current testing inspection technique. Permeability is the ease with which a material can be magnetized. The greater the permeability the smaller the depth of penetration. Nonmagnetic metals such as austenitic stainless steels, aluminum, and copper have very low permeability, whereas ferritic steels have a magnetic permeability several hundred times greater. Eddy current density is higher, and defect sensitivity is greatest, at the surface and this decreases with depth. The rate of the decrease depends on the “conductivity” and “permeability” of the metal. The conductivity of the material affects the depth of penetration. There is a greater flow of eddy current at the surface in high-conductivity metals and a decrease in penetration in metals such as copper and aluminum. The depth of penetration may be varied by changing the frequency of the alternation current—the lower the frequency, the greater depth of penetration. Therefore, high frequencies can be used to detect near-surface defects and low-frequencies to detect deeper defects. Unfortunately, as the frequency is decreased to give greater penetration, the defect detection sensitivity is also reduced. There is therefore, for each test, an optimum frequency to give the required depth of penetration and sensitivity. However, eddy current inspection only detects surface or near-surface defects, it is very sensitive to a wide range of parameters related to the conductivity and magnetic permeability of the test sample and is very sensitive to lift-off variations. Radiographic inspection has the advantage over many other NDE techniques in that analysis and interpretation are almost intuitive. Amongst radiographic methods, X-ray

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tomography excels where information is needed in three spatial dimensions. Babout et al. (2006) conducted a comprehensive study to observe intergranular SCC in a sensitized type 302 stainless steel wire, using high-resolution X-ray microtomography. Tomography enables the development and failure of crack-bridging ligaments to be studied in detail in three dimensions. Direct comparison of these features has been made with SEM fractography. The crack bridges failed in a ductile manner, with a morphology that is consistent with nonsensitized low-energy grain boundaries. However, despite the advantages, radiation techniques have serious safety concerns due to possible overexposure to large amounts of radiation. In addition, a closed crack will generally only be detectable in a radiograph at certain orientations, ideally when the long dimension of the crack is parallel to the direction of radiation propagation (Babout et al., 2006). Various ultrasonic techniques have been used for SCC detection, in particular, time of flight diffraction (TOFD). Time of flight diffraction and imaging (ToFDI) is a new technique utilizing a sparse array of transducers and signal processing to improve B-Scan output and create a cross-sectional image of a sample. This paper describes preliminary work demonstrating the concept, including; Finite Element Modeling (FEM), basic processing, and likely applications. The eventual aim is for fast and automated detection, identification, positioning, and sizing for all defects in a sample with known basic characteristics, such as bulk and shear elastic moduli. This technique relies on the detection of weak diffracted waves arising at the edges or tip of a crack, and can locate and size defects either within the bulk of a sample, or on the surface. Although TOFD is well understood and widely used it has some limitations, such as the assumption that there is no interference from other wavemodes. In some geometries, this will limit its applicability to cases where there is only a single defect, thus research to add new features and remove some limitations is still being performed (Petcher and Dixon, 2009). Standard ultrasonic measurements, particularly those looking for reflections of bulk waves from defects, have difficulties due to the low reflection and transmission coefficients for closed and partially closed defects. However, recent work looking at the interaction of surface waves with surface-breaking defects in the near field has shown several enhancement mechanisms which can be used for the identification of cracking (Hernandez-Valle et al., 2014). For Rayleigh wave propagation on thick samples, the signal enhancement observed when scanning the detector across the crack is due to the constructive interference of incident, reflected, and mode-converted waves (Edwards et al., 2006). Recent progress in the field of non-contact ultrasonic testing has led to the development of a practically viable system for generating and detecting wideband Rayleigh waves on electrically conducting or magnetic samples using electromagnetic acoustic transducers (EMATs). This system has been used to gauge the depth and position of surface-breaking defects and has many applications including metal billet testing and detecting and sizing gauge corner cracking in rails. Edwards et al. (2006) reported experiments calibrating the response of EMATs when a defect is present between the generator and receiver, using a calibration sample with slots machined perpendicular to the surface to simulate surfacebreaking cracks. The depth of the defect can be gauged in the time domain and frequency domain, with an accurate “fingerprint” of the position given by an enhancement of the signal when the receiver is close to the defect. The best choice of EMAT design for different

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777

applications was discussed, as is the best position for the receive EMAT to avoid areas of interference between the Rayleigh wave and bulk waves diffracted from the crack tip. For defects propagating at an angle to the surface, where the local thickness changes throughout the defect, further large enhancements are also seen in the time and frequency domains (Dutton et al., 2011). Dutton et al. (2011) investigated the interaction of Rayleigh waves with cracks which have a wide range of angles and depths relative to the surface, using a non-contact laser generation and detection system. They observed a clear variation of the reflection and transmission coefficients with both crack angle and length in both the out-ofplane and in-plane components. Their 3D finite element model was further enhanced the understanding of the reflection and transmission behavior, and helped identify angled defects. Knowledge of these effects is essential to correctly gauge the severity of surface cracking. Similar effects are seen when scanning thin samples using Lamb waves, with enhancements observed as an increase in magnitude of the signal at certain frequencies (Clough and Edwards, 2012). Clough and Edwards (2012) presented surface wave enhancements for Lamb waves propagating in plates. By tracking frequency intensities in selected regions of time
frequency representations, they observed frequency enhancement in the near field, due to constructive interference of the incident wave mode with those reflected and mode converted at the defect. This was explained using two test models; a squarebased notch and an opening crack, which are used to predict the contribution to the outof-plane displacement from the reflected and mode-converted waves. These distinctive features can be used to identify the defect and give some information about its geometry. For laser generation, further enhancement effects have been observed due to the changes in generation conditions when the generation spot is over a defect (starting with Xiao and Nagy, 1998). As the laser spot passes over the defect, the boundary conditions of generation on the surface will change, and this has been shown to give an increase in the magnitude of the signal at certain frequencies. If the defect is partially closed and the laser spot source is directly illuminating the defect, then the material will also undergo thermooptic crack closure, which has been shown to produce higher-order frequency components (Xiao and Nagy, 1998). Hernandez-Valle et al. (2014) examined the near-field interactions of laser-generated ultrasonic waves with SCC in stainless steel pipe samples removed from service, and use the ultrasonic signal enhancement to resolve the spatial extent and geometric alignment of those cracks. Ultrasonic waves generated in bounded media, such as pipes, take the form of guided waves. These travel along the pipe with different propagation and displacement behavior depending on the particular wave mode (e.g., longitudinal, torsional, or flexural modes in pipes, and higher-orders of each of these). The particular wavemodes generated depend on the pipe geometry, the material, the generation source used, and also the testing frequency. Quantification of the enhancement effect for guided waves in the time domain is complicated due to the presence in most cases of more than one wave mode, thus time
frequency analysis is performed in order to highlight which modes were generated and/or enhanced. This eliminates the presumption of a waveform as done with Rayleigh or Lamb waveforms, as discussed earlier. Fig. 10.30 depicts the experimental setup used by Hernandez-Valle et al. (2014). By using a time
frequency analysis on each A-Scan at each scan point to identify the arrival time of each frequency component, Hernandez-Valle et al. (2014) were able to

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Pipe sample Scan

3.9

step

Scan dir

= 0.5

mm

°

Generation laser

3.9

Scanned region

Detection point (Laser or EMAT)

Sam

50 mm

SCC

270 mm

Sample A

mm

ple B

Scanned regio n

(A) Set-up

(B) Pipe samples

FIGURE 10.30 Experimental setup used for inspection of stainless steel pipes containing SCC for laser or EMAT detection (A). Dimensions and scanned regions of both samples are shown in (B), with a schematic of the orientation of the measured defects relative to the pipe.

generate pictures shown in Fig. 10.10. Each wave mode has a frequency-dependent velocity which can be calculated, and hence the sonogram analysis used here is able to identify modes based on their arrival times, and allow identification of modes which show sensitivity to the presence of a surface-breaking defect. An increase in the magnitudes of these modes at a defect can then be measured through windowing the correct region of the sonogram, and used for the construction of surface plots that resolve the spatial extent and geometric alignment of SCC in the pipe surface (Fig. 10.31). 10.4.2.3 Management of the stress-corrosion cracking threat Compliance with the OPS advisory recommending pipeline owners and operators consider the SCC threat requires systematic and defensible procedures that are appropriate for the pipeline system of interest. The OPS advisory refers to Appendix A3 “Stress Corrosion Cracking Threat” of ASME B3 1.8S, Managing System Integrity of Gas Pipelines, which lists the following data elements for screening pipeline segments for the potential for SCC (Carson et al., 2005): • • • • •

Age of pipe Operating stress level Operating temperature Distance of the segment from a compressor station Coating type

Whereas procedures can and should be tailored appropriately for each pipeline system, pipeline systems could be classified into three general categories for management of SCC: • No known SCC occurrence in the pipeline system;

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10.4 Types of corrosion

Frequency (MHz)

5

50

4 40 3

30

2 20

Amplitude (nm)

1 10 0 60 0 -60 10

20

30

40

Arrival time (μs)

(A) Reference Frequency (MHz)

5

50

4

40

3 30 2 20

Amplitude (nm)

1 10 0 60 0 -60 10

15

20 25 Arrival time (μs)

30

35

40

(B) Enchanced FIGURE 10.31 Sonograms with and without defect present for the laser source passing over defect region (Hernandez-Valle et al., 2014).

• SCC detected in the pipeline system by ILI or direct examination; • Hydrostatic test or in-service failures due to SCC in pipeline system. Prudent management of SCC in a pipeline system that has experienced no known occurrences of SCC in the system might include the following actions: • Basic SCC awareness training of all staff and field employees responsible for operation and maintenance of the pipeline system.

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• MT or PT of bare pipe surfaces exposed for examination performed by a nondestructive evaluation (NDE) technician trained in detection of SCC of buried pipelines. • Documentation of each examination for SCC, including location, observations, and findings. The above actions would improve the probability of identifying the presence of SCC before a service leak or rupture. Prudent management of SCC in a pipeline system that has experienced one or more confirmed incidents of SCC might include each of the above actions, including: • Systematic identification and examination of other potential locations of SCC based upon the observation of conditions associated with the confirmed SCC incidents. • Scheduled hydrostatic testing or ILI of valve sections that have experienced multiple confirmed incidents of SCC. Prudent management of SCC in a pipeline system that has experienced one or more hydrostatic testing or in-service leaks or ruptures attributed to SCC might include each of the above actions, including: • Temporary pressure reduction followed by spike hydrotest or ILI of each valve section that experienced hydrostatic testing or in-service failure (leak or rupture) before return to service. • Periodic reexamination of valve sections that have experienced confirmed incidents of SCC at an interval selected to avoid in-service failure. Pipeline owners and operators may elect to implement additional measures to identify and mitigate SCC in their systems. These measures may depend upon a variety of conditions, such as the anticipated consequences of in-service rupture due to SCC. Likewise, OPS may elect to impose additional measures to manage SCC depending upon the specific circumstances, especially those involving leaks and ruptures associated with SCC. Based on the current understanding of SCC, the most cost-effective mitigation of SCC, as well as external corrosion, is to ensure integrity of the external coating for the life of the pipeline. This requires, at a minimum, the following aspects: • Systematic selection of coating systems for both the pipe and joints with known resistance to disbonding and other degradation in the expected service conditions; • Detailed specification of the coating material, surface preparation, and coating application parameters, ensuring the anticipated quality of the selected coating systems; • Diligent quality control during surface preparation and coating application, as well as during transportation, stringing, joining, and lowering; • Sufficient padding of the pipeline with backfill that will not damage the coating during the useful life of the pipeline; • Operation of the cathodic protection system in a manner that avoids premature degradation of the coating.

10.4.3 Localized corrosion There are several types of localized corrosion.

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10.4.3.1 Crevice corrosion The attack may occur in shielded areas and crevices, as well as on metal surfaces prone to corrosives. Crevice corrosion is a form of localized corrosion on hard-to-reach metal surfaces, such as interstices in which a solution is trapped and not renewed (Vagel, 2020). This form of corrosion most often involves confined parts of mechanical or welded assemblies. However, crevice corrosion can also develop in the meniscus at the water line, under accumulated marine dirt, and under deposits accumulated in areas of liquid stagnation. Its origin often depends on the design of structures where inaccessible gaps exist. Even very narrow gaps of only a few μm can be the origin of crevice corrosion. Crevice corrosion has the peculiarity of taking place in only a few microliters of electrolyte. In such small and very confined volumes, the corrosion resistance is different from that observed in the bulk solution. This is due to the buildup of corrosion products or by the diminution of some reactants induced by the specificity of laws of mass transport in confined aqueous media. Crevice corrosion is subjective to the specific nature of alloys. Pitting and crevice corrosion of stainless steels in chloride solutions are frequently found together, the most frequent observation being that stainless steels will fail most frequently by crevice corrosion, rather than by pitting. The prevalence of crevice corrosion, over pitting, has led to the development of a special cell, known as the Avesta cell, where pitting of stainless steels could be measured without the interference of crevice corrosion (Alvarez and Galvele, 2010). Susceptibility to crevice corrosion was found to be related to overpotential values, η, as shown in Table 10.20. This table shows that Nickel is the only metal that itself exhibits crevice corrosion in its elemental form (without an alloy).

TABLE 10.20 Overpotential values, η, versus crevice corrosion susceptibility for various metals and alloys in NaCl solutions. Metal

ηmV

Crevice corrosion

Al
3Zn

10

No

Cadmium

B20

No

Zinc

B20

No

Iron

B30

No

Al
3Cu

40

No

Al
3Mg

150

No

Aluminum

170

No

Nickel

470

Yes

Fe
18Cr

670

Yes

Fe
18Cr
1Mo

740

Yes

Fe
18Cr
2Mo

880

Yes

Fe
18Cr
5Mo

1000

Yes

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Wilde and Williams found an empirical relation that related the difference Ep
Er and the susceptibility to crevice corrosion in seawater. The anodic reaction inside the pit allows to explain the data in Table 10.20, as well as the empirical relation found by Wilde and Williams. These authors showed that the larger the difference between the pitting potential and the repassivation potential, Ep
Er, the more susceptible the alloy was to crevice corrosion. It is important to notice that the technique developed by Wilde and Williams assumes that the depth of the pits is the same in all the samples under comparison and that this condition is achieved when the current density reaches 0.2 A/cm2. Nevertheless, this condition will be true only when the number of pits in all the tested samples is similar. Crevice corrosion is a localized attack on the material, which is usually associated with a stagnant solution on the microenvironment level. For microbially influenced corrosion (MIC), the stagnant solution in a crack or small pit will have a high pH level than the surrounding environment. Crevice corrosion can be caused by biofouling deposits like iron hydroxide. APB is usually associated with crevice corrosion because of the high pH level. Typically, a microscope or other high-magnification device must be used to identify crevice corrosion. In Fig. 10.32, crevice corrosion is occurring under a shield. This shield could be a coating or a lining that allows a stagnant solution to increase pH level. 10.4.3.2 Pitting corrosion Pitting is a type of corrosion that occurs in materials that have protective films. It is an attack with localized holes on the metal’s surface. The attack can penetrate the metal very rapidly, while some parts of the metal surface remain free from corrosion. Pitting is vigorous when the solution on the metal surface contains chloride, hypochlorite, or FIGURE 10.32

Depiction of crevice corrosion (Makhlouf and Botello, 2018).

Crevice corrosion Air

O2 Na+

O2

CI– OH–

Na+

CI–

OH–

Shield

Fe(OH)3 e–

e–

Fe2+ H+

H+

CI–

CI–

Passive film Steel

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PICTURE 10.1 Postexamination should reveal the local cathode since it will remain impervious to the corrosion attack. Source: From NACE (2021). Local cathode

TABLE 10.21

The actual chemical composition for EN 1.4404. Typical composition (wt.%)

C

Cr

Ni

Mo

N

Si

Mn

Cu

0.021

17.2

10.1

2.1

0.038

0.45

1.65

0.39

bromide ions. Other harmful solutions are those that contain fluorides and iodides, while sulfides and water are known to enhance the pitting process. This form of attack results in metal holes. In such cases, the holes may be large or small in diameter. Pits can be close together or isolated and may appear as a coarse surface. In general, it can be described as cavities with surface diameter almost the same size as their depth (Picture 10.1). The main pitting corrosion mechanism involves aggressive anionic species, which is mostly caused by chloride ions (Akpanyung and Loto, 2019). The aggressiveness of pitting varies with the logarithm of the bulk chloride concentration. This results from the Arrhenius equation. Mameng et al. (2017) determined the limiting conditions for pitting corrosion using EN 1.4404 in terms of the environmental parameters such as temperature, potential, and chloride concentration. Table 10.21 shows the composition of this product. Extensive testing was done with a combination of short-term electrochemical measurements and long-term chlorination experiments. Results are discussed in light of the current understanding of the critical levels of key parameters for pitting corrosion. The results from the long-term chlorination tests can be used to construct the same type of concentration-temperature maps as for the short-term tests. The data are shown in Fig. 10.33 and represent the maximum temperatures and chloride concentrations that can be tolerated in slightly chlorinated (1 mg/L) chloride environments.

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FIGURE 10.33 Engineering diagram for EN 1.4404 based on immersion testing in chlorinated environments.

No corrosion Corrosion Long term chlorination 90

Temperature (°C)

80 70 60

Pitting corrosion

50 40 30 20

No corrosion

10 0 1

10

100

1000

10000

100000 1000000

Chloride concentration (ppm)

Chloride ion, anion of strong acid, tends to pose high level of solubility to metallic cations. This interferes with passivation of the metallic structure. This is because chloride ions have relative small anion with a high diffusivity. The pitting action on structures can be promoted by the availability of oxidizing agents in chloride environment. Most of the oxidants promote the probability of the occurrence of pitting corrosion by supplying additional cathodic reactants, hence resulting in an increased local potential. In general, the main oxidizing agent is dissolved oxygen. Anode formation is a necessity for pitting formation. This results in local corrosion cell formation. The anode formation may be through the following: 1. Heterogeneity of the interface of the corrosive metal. This absence of uniformity on the surface of the metal contributes to the availability of grain boundaries, impurities, niches, rough surfaces, etc. Also, concentration cells can be formed due to environmental differences on the surface. 2. Passive film demolition: This leads to the formation of small anodes, which leads to many anode sites while the rest of surface serves as cathode. This leads to a disadvantageous area ratio. 3. Debris/solid deposition on the metal surface which results to the formation of anodic and Cathodic sites. 4. Active passive cell formation is accompanied by high potential difference by forming small anode on the passive surface. Passive metal around the anode doesn’t promote pitting because of the cathode formed. It serves as oxygen reduction site. The corrosion products produced at the anode do not spread the cathode. This corrosion rather penetrates the metal instead of spreading thereby initiating pitting. A specific characteristic potential of the passive metal exists beyond which pitting can be initiated. This potential is called pitting potential (Ep). Pitting potential is the most determining factor in the existence of pitting. Ep is the least voltage

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or potential at which pits develop or grow on a metallic surface. The pitting potential is the potential below which pitting does not occur, but forms passivating film. The potential below which pitting does not propagate is termed passivation potential. The pitting process involves the following steps: 1. Anodic site formation is the first stage in pitting where the passive protective layer on the surface of the metal is destroyed. The destruction of the protective film may be done chemically or mechanically. M-Mn1 1 ne It is then balanced by reacting oxygen on the adjacent surface at the Cathode: O2 1 2H2 O 1 4e2 -4OH2 2. The continuous dissolution of metal results in the accumulation of outrageous positive ions (M 1 ) at the anodic zone. This is a self-stimulating and self-propagating process. Neutralization of charges is sustained by the negative ions (anions), like the chloride which comes from the electrolyte (using seawater as a sample). M1 Cl1H2 -MOH1H2 Cl2 3. The positive charges are also kept neutralized by the hydroxyl ions (OH 2 ) through hydrolysis process. 4. Repassivation is prevented by the presence of hydrogen ion and chloride content. This process produces free acid while the value of pH at the base of the pit is significantly decreased (1.5
1.0). 5. The rate of migration of chloride ions increases with dissolution rate at the anode. This makes the reaction to be time-dependent and leading to the formation of more M 1 Cl2 and the hydrolysis of H1Cl2. 6. These processes go on till the point of perforation of the metal. This is an autocatalytic process that advances with time leading to more metal dissolution. 7. The metal finally perforates and thereby causing the termination of the process. From the above processes, we have three main pitting processes: pitting initiation, pitting propagation, and pitting termination. The pit corrosion growth rate is measured by dissolution of metallic cations diffusion from the inner pit. This is independent of the electrode potential of the metals. The major pitting condition occurrence is an electrochemical potential shift in the direction of a more positive one than a certain critical value, considered as pitting potential. There are three main stages in pitting corrosion: 1. 2. 3. 1.

Pitting nucleation or passive layer breakdown Metastable pitting Steady-state pitting. Passive film breakdown and pit initiation: Mutual repulsion is formed when damaging ions are absorbed on the passive film surface thereby lowering the tension on the interfacial surface. The breaking of the passive film occurs when there is enough repulsive force. The phenomenon behind the passive film breakdown and its initiation

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details is not well understood but can be attributed to inherent inhomogeneity within a homogeneous system, for instance in the paint. The onset is also difficult to detect because of its minuscule size. The site of passive film passive films exist on stainless steel’s surface in presence of air, which triggers oxidation of the primary metal in an alloy. As discussed earlier, the formation of oxide leads to the development of a thin passive film, which acts as a corrosion-resistant layer. Pit initiation duration is as little as microseconds and it greatly relies on the nature of material surfaces. Surface defects as a result of manufacturing issues like installation challenges, procedure maintenance inadequacy, and environment changes can influence the initiation of pits materials. The parameters which contribute to pitting initiation and propagation include: a. Localized chemical or mechanical damage to the protective oxide film— Environmental parameters that can promote the breakdown of the film, such as low pH, elevated concentration of chloride, and less dissolved oxygen concentrations. These parameters have the capacity to destabilize the protective oxide film, hence initiating pits. b. Inadequate protective coating application or protective damages—Availability of irregularities in the metallic structure of the component like nonmetallic inclusions. 2. Metastable: This is the stage of pitting corrosion that is formed and latter disappears due to passive film formed on the metallic alloy. It is only those pits that survive the metastable stage that turns into growing stable pits. Metastable pits are established on the brink of stability. The metastable pit occurs at much lower potentiostatic potentials that are highly less than the potentials of occurrence of the pitting corrosion itself. It is microscopic in nature and has a short lifespan. Its low potentials described the ability of metals to resist the action of pitting. This is because lower potential of alloy repassivation corresponds to greater resistance of alloys to pitting. The passive film strength determines the ease at which a metal can resist pitting formation. The perforated cover is required for metastable growth over the pit mouth to promote extra barriers to diffusion. This keeps the aggressive pit anolyte stable. Research shows that the factors which aid the metastable pitting and its transition to stable pitting are the size and geometry of active impurities and the presence of fatigue stress (Loto, 2013). Loto (2013) studied the resistance of austenitic stainless steel type 304 to pitting corrosion in solutions of sulfuric acid (2 and 5 M) with and without sodium chloride addition by linear polarization technique. The pitting and passivation potentials, corrosion rate, and current density were analyzed with respect to the chloride ion concentration. Under anodic polarization, the stainless steels in sulfuric acid solution acquired a passive state, with breakdown at the transpassive region (pitting potential); however, this was greatly reduced with the addition of sodium chloride which led to a sharp increase in current at potentials significantly lower than the value that necessitates pitting in the acid media due to rapid breakdown of the passive film and development of local pits. Results obtained establish the dynamic relationship and interaction between the sulfate/chloride ion concentration and electrochemical potentials in the corrosion behavior of the ferrous alloy at ambient temperature. Alloying metals are very important factors to stabilize an alloy against general and localized corrosion. For instance, for stainless steel Cr plays a very important role for iron and nickel base

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Air

O2 O2 OH-

+

Na Na+ Cl Fe(OH)3 OHe-

e

O2

Cl-

Na+

Fe(OH)3

O2

ClOH-

OH-

-

Cl H+ Fe2+ H+ Cl H+ ClClH+

Fe2+

e-

e-

Passive film

Stainless steel FIGURE 10.34

Schematic of an actively growing pit in iron.

metals. It accumulates in the passive layer because of its extremely small dissolution currents even in strongly acidic electrolytes. Fig. 10.34 depicts a propagating pit in an iron or nickelbased alloy containing chromium in a chloride-containing environment. Anodic reactions inside the pit: Fe2Fe21 1 2e 2 ðdissolution of ironÞ The electrons are given up by the anode flow to the cathode (passivated surface) where they are discharged in the cathodic reaction: 1=2O2 1 H2 O 1 2e 2 22ðOH2 Þ As a result of these reactions, the electrolyte enclosed in the pit gains a positive electrical charge in contrast to the electrolyte surrounding the pit, which becomes negatively charged. The positively charged pit attracts negative ions of chlorine Cl2 increasing the acidity of the electrolyte according to the reaction. FeCl2 1 2H2 O2FeðOHÞ2 1 2HCl The pH of the electrolyte inside the pit decreases which causes further acceleration of the corrosion process. Large ratios between the anode and cathode areas favor the increase in the corrosion rate and the corrosion products (Fe(OH3)) which form around the pit resulting in further separation of its electrolyte; however, the formation of a pit does not require the complete dissolution of the inclusion. It has been proposed that the special chemistry within the pit electrolyte with the formation of sulfur-containing compounds such as sulfides, sulfur, sulfites, and even sulfates has a strong influence on localized corrosion (Fig. 10.35). 3. Stable pit: The breakdown of passive films and the initiations of pits certainly show that a stable pit will grow. Metastable pit precedes the stable pitting. The termination of the passive film leads to the formation of stable growth of pit for ongoing propagation, while the pit depth serves as a diffusion barrier. Constant mean pit stability of products beyond the critical value characterized passive stability. If the film is prematurely lost prior to the attainment of critical pit stability of the product, the anolyte pit becomes diluted and repassivation occurs. The occurrence and disappearance of metastable pits is usually within

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FIGURE 10.35

Schematic illustrations of the initiation and propagation stage. Source: From Presuel-Moreno et al. (2008).

Structure service life Cumulative Corrosion Damage

Cracks, Spalling CT

Chloride ion diffusion Time to corrosion initiation 1

Corrosion rate

Corrosion Time Propagation 2

a few seconds. The pit growth depends on the electrolytic composition and acidity (pH), composition of the alloy, and potential within the pit. The kinetic growth of pit is dependent on the electrolytic diffusion rate within the pit. Aggressive anion electrolytes, majorly the halogens, sulfates and sulfides often promote dissolution of anodic ions. The stability of the electrolyte at the critical concentration in the pit promotes the growth of the pit. These conditions at their lowest should be adequately aggressive to hinder repassivation. Pitting distribution current transients are dependent on electrode potential as against the rate of growth of the individual pits. Pit nucleation site, specifically its geometry, is accountable for potential distribution. More Shallow and open sites are activated only at both greater potential and current density, hence susceptible to attain stability. Previous studies have identified duplex stainless steel and austenitic stainless steel (with high PREN and with Ni and Mo) as alloys with a high chloride threshold. One of the methods developed to determine the chloride threshold concentration was to do an anodic potential hold (1200 mVsce) on the studied alloy while exposed to simulated pore solution with chlorides (Tellez, 2013). Tests in solution provided comparable rankings of the different alloys. In recent years, the use of corrosion-resistant alloys (e.g., duplex stainless steels) has been suggested as a way to achieve a long maintenance-free service life. Two corrosion resistance alloys (CRA) duplex stainless steel rebars, UNS32304 and UNS32101, embedded in concrete were selected by Tellez (2013) to investigate corrosion initiation and corrosion propagation stages. He developed a methodology that allows for corrosion to initiate and propagate on concrete specimens embedded with CRAs and initially chloride free. He observed that stray current might have caused an accelerated corrosion rate (due to additional electric field application once corrosion had initiated) on reinforcing bar(s) where corrosion had initiated. Pit with open (uncovered) or covered mouth can be formed by pitting corrosion via semipermeable membrane products. There are two major types of shapes. They are sometimes flat-walled, showing metallic crystal structure while some may be totally irregular in shape. Pit shapes are commonly classified into trough pits (upper) and sideway pits (lower) as shown in Fig. 10.36. The cavities of Pitting may be filled with corroded products forming caps over it and at times forming nodules or tubercles.

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Trough Pits Narrow

Deep

Shallow

Wide

Ellipcal

vercal

grain aack

Sideway Pits Subsurface

FIGURE 10.36

Undercung

Horizontal grain aack

Shape of pitting corrosion. Source: From NACE (2021).

10.4.3.2.1 Factor affecting pitting corrosion

Environmental factors, pitting potential, metallic composition, temperature, surface conditions, and among others are the diverse parameters influencing pitting corrosion. Among these factors, environmental parameter is the most critical factor. The concentration of aggressive ion, pH, and inhibitor concentration are some of the environmental factors that affect pitting. Composition and microstructure greatly influence pitting tendency of alloys (Smialowska-Szklarska, 1986). A common tool in alloy design is the pitting resistance equivalent number (PREN). It gives an impression of the relative influence of different alloying elements on the pitting resistance. It assumes that other parameters influencing the pitting resistance are kept constant, such as surface condition, heat treatment history, and inclusion levels. For nitrogen, values between 12 and 30 have been reported. The higher value is frequently given for austeno-ferritic (duplex) stainless steels. The most common form of the PREN formula is in wt.%: PRENwt 5 ½wt:% Cr 1 3:3 3 ½wt:% Mo 1 ð16-30Þ 3 ½wt:% N

(10.11)

There is no apparent influence of nickel for concentrations below 40%. Manganese has been attributed to a negative influence, but this is connected to the presence of sulfur, which contributes to the formation of manganese sulfides. Both molybdenum and nitrogen have marked positive effects on the pitting resistance but need a significant amount of chromium to have the desired effect. It is also interesting to consider the at%-version: PRENat 5 ½at:% Cr 1 6:1 3 ½at:% Mo 1 ð4:3 2 8:1Þ 3 ½at:% N

(10.12)

This variant reflects the relative strength of the elements and their role in dissolution and passivation reactions. The pitting susceptibility of alloys can be mitigated by the introduction of some alloying elements. The passivation of stainless steel is enhanced by Chromium concentration. The resistance of Fe
Cr alloy to pitting can be promoted by increasing Ni concentration, which moderately stabilizes the austenitic phase. Mo in the presence of chromium inhibits the

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pitting action of stainless steel. The addition of minute amount of nitrogen and tungsten can promote pitting resistance of stainless steel. Temperature: Some materials may not pit below certain value of temperature, which could be very sharp and reproducible. Hence, temperature is considered as one of the major pitting factors. This can be influenced by altering temperature at constant range of fixed potentials, or altering the potential at constant range of temperature experiments. Greatly high breakdown potential is noticed at low temperatures which correspond to transpassive dissolution rather than localized corrosion. Pitting corrosion is observed at a potential far below the transpassive breakdown potential just beyond the critical pitting temperature (CPT). The values of CPT are not dependent on parameters of the environment and applied potential over a wide range. This gives the estimate of the resistance to stable pit propagation. The pitting potential decreases with a corresponding increase in temperature and chloride concentration. 10.4.3.3 Intergranular Intergranular corrosion (IGC) is a form of localized corrosion, characterized by preferential corrosion at grain boundaries or areas adjacent to them, with little or negligible attack on the grains. Similarly to other forms of localized corrosion, it mainly occurs on passive alloys exposed to specific corrodents. IGC of commercial alloys is generally caused by enrichment or depletion of alloying elements in the area adjacent to the grain boundaries, by intergranular precipitation of second-phase particles or by the presence of alloy impurities segregated at the grain boundaries. Effects of grain boundaries have little or no effect in almost all metal applications. In such cases, metal corrosion results in a uniform attack, since grain boundaries are more reactive compared to the matrix. In some circumstances, grain interfaces are extremely reactive, leading to corrosion. Corrosive environments that are highly different from the regular environment usually play a role in the propagation and initiation of corrosion pits. This makes the task of prediction tremendously complicated. Hence, it requires sophisticated computational and experimental tools to gain more advanced understanding of localized corrosion. Most alloys, after being submitted to specific heat treatments or as a result of fabrication processes, experience IGC when exposed to an appropriate environment. In this regard, alloys of two more metals, already in an unstable state, make the resulting product more vulnerable to corrosion. Fig. 10.37 shows how such vulnerability is correlated with artificial processing techniques and ensuing degradation in sustainability. Vulnerability to corrosion increases as the degree of amalgamation is increased. For instance, a large number of cases involve Fe-Ni-Cr alloys, either Fe-based or Ni-based, particularly austenitic stainless steels (SS). Austenitic SSs, such as AISI 304 (UNS S30400), after being slowly cooled through the temperature range of 850 C to 550 C, might become susceptible to IGC in relatively benign environments. The phenomenon is called “sensitization” to indicate that the alloy is sensitive to grain boundary attack (Cragnolino, 2021). Sensitization may occur as a result of various situations: (1) slow cooling from the annealing temperature, which could be the case in heavy section components; (2) stress relieving in the sensitization range, which is possible when ferritic steels that require such treatment

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791 FIGURE 10.37 Corrosion, sustainability, and processing of metal.

are welded to austenitic steel parts that become sensitized; (3) welding operations, which is by far the most common cause of sensitization. The failure of AISI 304 and 316 (UNS S31600) SS components due to IGC in the heat-affected zone (HAZ) of the weld, the socalled weld decay, has been a problem in many industrial applications. Sensitization of austenitic Fe
Cr
Ni alloys is caused by precipitation of Cr-rich carbides at grain boundaries, accompanied by Cr depletion of the regions adjacent to the carbides to levels below those required for passivation. Within the temperature range of sensitization, C diffuses toward the grain boundaries quite readily, whereas the bulk diffusion of Cr from the austenitic matrix to the depleted region is too slow to allow replenishment. Since at least 12 wt.% Cr is necessary to preserve passivity in an acidic medium, depletion of Cr below such level leads to IGC. However, if a sensitized austenitic SS is held long enough at the sensitization temperature, it becomes desensitized because Cr diffusion from the bulk replenishes the Cr-depleted region, even though the carbides are still precipitated. Austenitic SSs become less susceptible to sensitization, and hence IGC, by decreasing the C content or by adding alloying elements such as Ti or Nb which are stronger carbide formers than Cr. Ferritic and duplex SSs are also subject to sensitization, but their susceptibility is quite different. Ferritic SSs are sensitized at temperatures above 925 C by Cr depletion of the matrix in the vicinity of precipitated carbides and nitrides at grain boundaries. Even though the rate of sensitization is faster than that of the austenitic SSs, ferritic SSs are easily desensitized at about 650 C because the diffusion of Cr and C is faster than that in the austenitic phase. Duplex SSs, which contain austenite and ferrite as constituent phases, are far less susceptible to sensitization because typically the C content is lower than 0.03 wt.%. These alloys are more prone to exhibit precipitation of intermetallic phases, such as σ and χ, by slow cooling through the 900 C
700 C range due to their relatively high Cr and Mo content. However, the effect of these intermetallic precipitates is more pronounced in terms of impact properties than on corrosion. If the C content is higher, preferential precipitation of carbides at ferrite/austenite boundaries makes the duplex SS less prone to IGC because the depleted zone in the austenite phase can be easily replenished.

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In terms of IGC, Ni-based alloys can be divided into two groups: Ni
Cr
Fe alloys such as Alloys 600 (UNS N06600) and 800 (UNS N08800) and Ni
Cr
Mo alloys such as C-276 (UNS N10276) and C-22 (UNS N06022). The first group is also prone to IGC as a result of sensitization. Even though the C content is usually lower (0.02
0.05 wt.%) than in the AISI 304 or 316 SS, the solubility of C is also lower in the Ni-base alloys and shorter heat treatments induce sensitization, and therefore, IGC in acidic environments. In the case of NiCr-Mo alloys such as C-22, preferential precipitation of intermetallic phases (μ and P) occurs upon heat treatment at temperatures around 600 C. These intermetallics, rich in Cr and Mo, promote the depletion of both alloying elements in the region around them and facilitate IGC in acidic environments. An example of IGC of Alloy 22 is shown in Fig. 10.38. IGC occurred in this case inside a crevice in which strongly acidic conditions prevailed. Segregation of impurities such as S or P to grain boundaries is also the cause of IGC, as they act as a trigger point. The IGC of austenitic SS in hot concentrated HNO3 has been attributed to the segregation of P to grain boundaries, whereas the segregation of S to the grain boundaries of Ni is the cause of IGC in H2SO4 solutions, in both cases at high oxidizing potentials. Aluminum alloys are also susceptible to IGC in Cl2 solutions as a result of certain thermal aging treatments that promote precipitation of intermetallic phases along grain boundaries. The associated depletion of noble alloying elements (e.g., Cu) or the enrichment of the active ones (e.g., Zn) facilitates the preferential dissolution of the depleted area or the intermetallic phases, respectively, at potentials above the Epit of each specific phase. There are many standard chemical and electrochemical tests for evaluating the susceptibility of alloys to IGC. As the number of metals increases in the amalgamation process, the vulnerability of the product to IGC increases. For instance, Wieczerzak and Bala (2019) presented the concept of hypoeutectic Fe
Cr
Ni
Mo
C alloys additionally strengthened by the Frank
Kasper

FIGURE

10.38 Micrographs showing an example of intergranular corrosion. Attack on alloy C-22 observed inside a crevice where acidified and concentrated chloride solutions exist (Cragnolino, 2021).

× 200

1 0 0P m

20kV

SwR I

# 0 01 5

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phases. Frank-Kasper (FK) phases are one of the largest groups of intermetallic compounds, known for their complex crystallographic structure and physical properties (Kattner, 2016). Applications of FK phases as high-temperature structural and superconducting materials have been studied broadly. Wieczerzak and Bala (2019) designed alloys using the CALPHAD approach (Katthner, 2016) in order to obtain a matrix with high corrosion resistance, similar to that of stainless steels, and wear resistance at room and elevated temperatures, achieved by the precipitation of eutectic carbides and the FK phases. The main design strategy is to produce alloys with a narrow solidification range and precipitations of the FK phases within the dendrites after heat treatment in order to reduce the mean free path of the matrix. The effect of molybdenum on the evolution of intermetallic phases in the Fe-25Cr-xMo-0.8C system was determined. Additionally, the influence of nickel in the Fe-25Cr-5Mo-xNi-0.8C system on phase composition of the matrix, as well as the stability and volume fraction of intermetallic phases were investigated. Lever-Rule and the modified Scheil
Gulliver solidifications were simulated for selected five alloys in order to investigate the phase precipitation sequence. The main design strategy is to produce alloys with a narrow solidification range and precipitations of the FK phases within the dendrites after heat treatment in order to reduce the mean free path of the matrix. The effect of molybdenum on the evolution of intermetallic phases in the Fe-25Cr-xMo-0.8C system was determined. Additionally, the influence of nickel in the Fe-25Cr-5Mo-xNi-0.8C system on phase composition of the matrix, as well as the stability and volume fraction of intermetallic phases were investigated. well as solidus and liquidus temperatures in the investigated systems. Fig. 10.39 sums up the work of Wieczerzak and Bala (2019).

10.5 Microbially influenced corrosion MIC can be defined as the deterioration of metals by natural processes directly or indirectly related to the activity of microorganisms. MIC affects many industries, such as petrochemical, ships and marine structures, power generation, aircraft fuel systems, wastewater facilities, cooling water systems, process industries, paper mills, and water supply and distribution systems. MIC refers to the influence of microorganisms on the kinetics of corrosion processes of metals and nonmetallic materials, caused by adhering to the interfaces (usually referred to as “biofilms”). The corrosion-relevant microbes like to attach to solids via exopolymeric substances (EPS), which give the main component of the slime and form biofilms at the solid
liquid interface (Telegdi et al., 2017). Every metal has at least one strain of bacteria that thrives in it (e.g., iron and manganese and sulfur oxidizers and reducers, slime formers, acid producers, etc.) and thereby produce biofilms around the metal. There are gradients of microorganisms, oxygen concentrations, and pH values inside the biofilm, which consists mostly of water, microbial metabolites, exopolymeric substances, organic, and inorganic molecules of the aqueous environment. Beneath this biofilm, corrosion initiates and progresses resulting in localized corrosion that can lead, if remained uncontrolled, to pinholes and leaks. Telegdi et al. (2020) discuss the different

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Design strategy Abrasive particles

Abrasive particles Crack A

A

10 5

[%]

0

300

rature

100 200

600

e Temp

400 500

900

1200

1500

1000 1100

700 800

%]

X phase 1300 1400

20 18 16 14 12 10 8 6 4 2 0

Ni [wt.

FIGURE 10.39

Temp

[°C] erature

0 100 200 300

Ni [wt. %]

600

20

900

18

700 800

16

1200

14

1100

12

1000

10

1400 1500

8

0 2 4 6 8 10 12 14 16 18 20

1300

6

FK phases

V phase

15

400 500

Ni [wt. %]

Temperature [°C]

90 80 70 60 50 40 30 20 10

[%]

4

A

A

20

n actio me fr Volu

n actio me fr Volu

100

Solidus 2

A

Frank-Kasper phases

Matrix

Liquidus

0

A A

A

Solidification range 1460 1440 1420 1400 1380 1360 1340 1320 1300 1280 1260 1240 1220

Abrasive particles

[°C]

Source of corrosion.

microbes responsible for MIC in oil and gas industry, classification of microorganisms, MIC mechanisms, and biofilm development, and factors necessary for its formation. It is well known that MIC can deteriorate metals exposed to seawater, freshwater, demineralized water, process chemicals, food stuffs, soils, aircraft fuels, human plasma, and sewage. Microorganisms can accelerate the rates of partial reactions and cause enhanced corrosion. MIC is one among the eight different types of corrosion. In many industries such as power generation, wastewater treatment plant, oil and gas production, MIC has been identified as the most dangerous (Lavanya, 2021). MIC contributes to approximately 20% of the annual losses.

10.5.1 Background Historically, corrosion has been synonymous with electrochemical processes. The very concept of stainless steel, amalgamation, use of paints, and PVC tapes revolve around chemically induced corrosion. As such, all remedies also address chemical forms of corrosion. For instance, the entire notion of the most successful corrosion prevention technique is cathodic protection. It is used to control the corrosion of a metal surface by making it the cathodic side of an electrochemical cell. The simplest method to apply this technique is by connecting the metal to be protected with another more easily corroded metal to act as

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the anode of the electrochemical cell. Curiously, both the metal to be protected and the sacrificial metal are refined metals, extracted from ores. As such they are inherently susceptible to corrosion. Although MIC is ubiquitous with direct or indirect involvement in corrosion, its role didn’t come to prominence until recently. MIC is indeed a serious and dangerous problem in the industry. The MIC corrosion was first mentioned in 1891 by Garrett, who gave an account of bacterial deterioration of lead-covered cables. MIC was known to be a key factor for numerous pipeline failures. One such incident of pipeline rupture took place in New Mexico in the year 2000. MIC was also a main suspect in the pipeline leak in Alaska on March 2, 2006, which led to a spike in oil prices worldwide (Xu and Gu, 2014). The subsequent report was published by Gaines who coupled the undesired microbial deterioration with the presence of sulfur in the corrosion products (Gaines, 1910). After the pioneering work of von Wolzoen Kuhr and van der Flugt (1934), until the 1960s, only a few publications reported practical cases. As early as in 1926, microbiologists isolated sulfate-reducing bacteria (SRB) in oil environment (Miranda et al., 2006; AlDarbi et al., 2002). This was a very significant development, as SRB forms the basis of most commonly occurring in the petroleum sector. The existence of the biofilm was first mentioned by Zobel in 1943, and then intensive research on the MIC started, which led to the acceptance of this special type of corrosion initiated and enhanced (and in some cases inhibited) by microorganisms. The development was supported by the elaboration/discovery of surface analytical, electrochemical, and microscopic techniques that promoted the clarification of the role of biotic and abiotic sulfide in the MIC. During the 1960s and the early 1970s, the research on MIC was devoted to objection or verification of the anaerobic iron corrosion provoked by SRB. The researchers focused on the explanation of MIC mechanisms by the cathodic polarization theory. The hindrance of the appropriate knowledge transfer among the different specialists explains the difficulty in reaching an adequate understanding of MIC. In the 1980s, which brought a significant progress in understanding MIC, several research groups carried out intensive work to elucidate the MIC mechanisms. An increasing intellectual and technical cross-fertilization of ideas elaborated by microbiologists, materials scientists, and electrochemists improved the understanding of MIC. The 1990s brought a breakthrough in knowledge of MIC. The tardiness was not only due to the lack of cooperation among specialists (chemists, microbiologists, and metallurgists) but to the lack of special instrumentation that could measure the destructive activity of microbes involved in a biofilm. The 21st century resulted in the further development of new analytical methods applicable either in laboratory or in industry. One of the most exciting advances in instrumentation that appeared in these years is the chemical/biochemical microsensors that can in situ analyze the changes in the oxygen level, in the pH value and in the concentration of different metabolites within the biofilm. Although the MIC is of electrochemical nature, the participation of microbes in these undesired reactions alters the metal-solution interface by the formation of biofilms.

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FIGURE 10.40

Schematic representation of microbially influenced corrosion and the environment.

10.5.2 Mechanism of microbially influenced corrosion MIC is the product of the combination of “three Ms” (Fig. 10.40): microorganisms, media (chemical composition and physical parameters, e.g., temperature and flow), and metals. Hamzah et al. (2013) investigated MIC mechanisms using a 304 stainless steel (SS) substrate in a nutrient-rich simulated seawater inoculated with Pseudomonas aeruginosa bacteria. Atomic force microscopy, SEM, and energy dispersive spectroscopy (EDS) techniques were used to analyze MIC behavior of 304 SS. Atomic force microscopy was used to observe the degree of pitting corrosion on 304 SS due to the presence of P. aeruginosa bacteria. SEM and EDS were used to analyze the biofilm layer formed on 304 SS. The considerable feature was the severe pitting corrosion of 304 SS due to the presence of P. aeruginosa in biofilm state. 10.5.2.1 Titanium Microbes can directly or indirectly disturb the integrity of practically any metal that have undergone modern refining process. As stated earlier, vulnerability to corrosion increases with the degree of refinement of a metal as well as degree of amalgamation. Most of them including copper, iron, nickel, aluminum, and their alloys, are more or less vulnerable to damage. Only titanium and its alloys are considered to be resistant (Biguetti et al., 2021). However, this is likely because bacteria that would interact with titanium are not yet identified. Biguetti et al. (2021) studied titanium surfaces exposed to critical environments (such as chronic infection and inflammation) and observed that these surfaces can undergo corrosion processes in vivo, leading to an unfavorable biological response and clinical failure. In this study, they characterized an experimental model to replicate the surface features of Ti corrosion process observed within in vivo failures, and the cellular, tissue and molecular events associated with corroded Ti surface implantation into subcutaneous and bone tissue of C57Bl/6 mice. Prior to in vivo implantation, commercially pure Ti Commercially pure titanium and Ti
6Al
4 V alloy (Ti64) specimens were exposed to electrochemical polarization in 30% citric acid, while being polarized at 9 V against a saturated calomel electrode for 20 minutes. The electrochemical attack induced accelerated corrosion on both Ti-based specimens, producing structural and chemical changes on the surface, comparable to changes observed in failed implants. Then, microscopy and molecular parameters for healing and inflammation were investigated following control and corroded Ti implantation in subcutaneous (cpTi disks) and oral osseointegration (Ti64 screws) models at 3, 7, 14, and 21 days. The host response was comparatively evaluated between control and corroded Ti groups by microCT (bone), histology (H&E, histomorphometry, immunostaining, and picrosirius red), and real-time PCR array for inflammatory and healings markers. Corroded cpTi disks and Ti64 screws induced a strong foreign body response (FBR) from 3 to 21 days post-implantation, with unremitting chronic inflammatory reaction lasting up to 21 days in both subcutaneous and osseointegration models. In the subcutaneous model, FBR was accompanied by increased amount

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of blood vessels and their molecular markers, as well as an increased TRAP 1 foreign body giant cell count. In the osseointegration model, failures were identified by an osteolytic reaction/bone loss detected by microCT and histological analyses. The corroded devices were associated with a dominant M1-type response, while controls showed transient inflammation, an M2-type response, and suitable healing and osseointegration. In conclusion, corrosion of Ti-based biomaterials induced exacerbated inflammatory response in both connective tissue and bone, linked to the upregulation of fibrosis, proinflammatory and osteoclastic markers, and resulted in unfavorable healing and osseointegration outcomes. 10.5.2.2 Carbon steel, copper, and aluminum These metals exhibit the most prolific MIC attacks. The growth cycle of SRB, Desulfovibrio caledoniensis, the influence of SRB on the corrosion activities of Q235, and the environmental parameters during a growth cycle in the presence and absence of oxygen were studied. Culture solutions with dissolved oxygen encouraged sluggish growth and rapid decay of SRB. Conductivity, pH, and sulfide anion concentration were affected by the growth process of SRB both under aerobic and anaerobic conditions. During the stationary growth phase, OCP shifted toward the positive end. Through the exponential growth phase the Rct (charge transfer resistance) increased rapidly while it decreased after the stationary phase (Wang et al., 2004). They studied the corrosion behavior of carbon steel, pure aluminum, and copper in seawater. The changes in corrosion potential (Ecorr) of metals immersed in seawater were investigated with electrochemical technology and epifluorescence microscopy. In natural seawater, changes in Ecorr were determined by the surface corrosion state of the metal. Ecorr of passive metals exposed to natural seawater shifted to noble direction for about 150 mV in one day and it didn’t change in sterile seawater. The in situ observation showed that biofilms settled on the surfaces of passive metals when Ecorr moved in noble direction. The bacteria number increased on the metal surface according to exponential law and it was in the same way with the ennoblement of Ecorr. The attachment of bacteria during the initial period played an important role in the ennoblement of Ecorr and it is believed that the carbohydrate and protein in the biofilm are reasons for this phenomenon. The double layer capacitance (Cdl) of passive metals decreased with time when immersed in natural seawater while remaining almost unchanged in sterile seawater. The increased thickness and reduced dielectric constant of Cdl may be the reason behind such behavior. 10.5.2.3 Aluminum
magnesium alloy The 2024-T31 aluminum
magnesium alloy was investigated for its susceptibility to microbial corrosion in the presence of SRB (Wan et al., 2010). The sample was immersed in various test solutions and maintained at a constant temperature of 30 C in an incubator. As time elapsed, microbial colonies and deposition of corrosion products were observed on the substrate. Biofilm and passivation film both were found to jointly control corrosion in 2024-T31 aluminum-magnesium alloy. SRB caused excessive corrosion in the alloy along with pitting on the metal surface. In the very beginning an uneven biofilm was observed on the metal surface which weakened in the mid-stage along with the growth of a protective passive film, therefore, reducing the corrosion rate. Later localized corrosion cells were formed accelerating corrosion

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(Wan et al., 2010). The growth cycle of SRB, D. caledoniensis, and the effect of SRB on the environmental parameters and corrosion behavior of Q235 steel during a growth cycle in aerobic (air- and O2-saturated culture solutions) and anaerobic (N22 saturated culture solutions) conditions were investigated. Oxygen dissolved in the culture solutions induced slow growth and fast decay of SRB. The growth process of SRB under anaerobic and aerobic conditions influenced sulfide anion concentration (Cs22), pH, and conductivity (κ). The values of Cs22 and κ under aerobic conditions were lower than those under anaerobic conditions, and the pH values increased from O2 to air to N2-saturated culture solutions. Aerobic conditions induced the OCP (EOC) to shift in the positive direction after the stationary phase of SRB growth. The charge transfer resistance (Rct) increased quickly during the exponential growth phase, almost maintained stability during the stationary phase, and decreased after the stationary phase in all three conditions, and the impedance magnitude decreased from O2 to air to N2-saturated culture solutions. The biofilms induced by SRB were observed by SEM under aerobic and anaerobic conditions, and EDS was performed in abiotic and SRB-containing systems to distinguish the corrosion products. The reasons for the effects of SRB on the environmental parameters and corrosion behavior of carbon steel are discussed (Elabbasy and Gadow, 2021). 10.5.2.4 Carbon steel The cost of carbon steel is cheaper as compared to few other metals. As such, it is commonly used. However, one of the disadvantages of using this metal is that it rusts easily resulting in environmental and economic losses (Elabbasy and Gadow, 2021). The effect of the expired tenoxicam drug as an inhibitor on the corrosion inhibition of carbon steel in 0.5 M HCl was examined at different concentrations. Besides, the effect of potassium iodide additives on inhibition was investigated. All of these are applied by three methods; electrochemical studies (electrochemical frequency modulation, potentiodynamic and electrochemical impedance spectroscopy), superficial studies (XPS, FTIR, and UV-spectroscopy), and theoretical studies (quantum chemistry calculations and molecular dynamic calculations). The presence of tenoxicam as an inhibitor in the solution gives an increase in charge transfer resistance and a decrease in the capacity of the double layer. Potentiodynamic polarization studies have demonstrated that tenoxicam is a mixed inhibitor. In this study, Elabbasy and Gadow (2021) examined the influence of temperature on the inhibition of corrosion of carbon steel and also computed the thermodynamic parameters. The potentiodynamic method designated that the inhibitor was used showed the best protection productivity of up to 81.0% for C-steel at 4 3 1024 M from tenoxicam in 0.5 M HCl solutions at 30 C. On the other hand, the inhibition efficiency (I%) increased synergistically with the addition of potassium iodide to 90.3%. Tenoxicam adsorption was found on the C-steel surface for Temkin’s isothermal obedience. The mechanism of the inhibition process was discussed in light of the chemical composition and theoretical study of the inhibitor probe. Expired Tenoxicam was first studied as a carbon steel corrosion inhibitor in a solution of hydrochloric acid. It provides a way to deal with expired medications, thus reducing environmental pollution. The study explored the inhibition mechanism affecting expired tenoxicam, and provided theoretical support for the results obtained from experimental studies. The expired tenoxicam drug can be used as a cheap and safe corrosion inhibitor for the studied system. CS and its alloys are used all over the world in boilers, pipelines, bridges, and so on. With relatively good corrosion resistance

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CS is also applied in marine environments (Stipaniˇcev et al., 2013). The influence of SRB on the corrosion behavior of carbon steel was studied in a laboratory test loop, continuously fed with nutrient-supplemented North Sea seawater. The main parts of the test loop, represented by two separated flow cells, were fitted with steel specimens. The test loop was operating anoxically for 2200 hours and each flow cell was three times inoculated with Desulfovıˆbrio alaskensıˆs or Desulfovıˆbrio desulfuricans species. Additionally, each flow cell was two times perturbed with antimicrobial treatments. Steel specimens exposed in flow cells exhibited comparable appearance and systems responding similarly to inoculations and antimicrobial treatments. The effect of the inoculations in both flow cells on the steel coupons’ electrochemical behavior was materialized as lower resistance to corrosion and higher surface activity or occurrence of localized pitting events. The localized surface attacks recognized in both flow cells after inoculations continued to progress with time, although bacterial activity was temporarily suppressed by antimicrobial treatment. Post-exposure sample evaluations might suggest that some particular steel surface areas have been subjected to a dramatic change in the corrosion mechanism from initial localized attack to general corrosion. The long-term exposure of the carbon steel specimens resulted in identifiable formation of biofilms and corrosion products. Corrosion deposits were characterized by a specific structure built of iron sulfides (FeS), sulfated green rust ¨ 4), Fe(III) oxyhydroxides (FeOOH), chukanovite (Fe2 (OH)2 (GR(S0422)), magnetite (Fe3U CO3). carbonated green rust (GR(C0322)) and some calcareous deposits. Presented factual evidence reinforced the idea that sulfidogenic species in natural seawater environment may cause localized damage with a specific surface pattern; however, this does not necessarily lead toward significantly elevated corrosion rates. Dissolved oxygen concentration and pH evolution were monitored during the 2200 hours of the test are shown in Fig. 10.41. During the first test stage, pH around 8.1, low cell density (,103 cells m/L), corresponding to indigene population naturally present in seawater, high sulfate (  3.5 3 103 ppm, i.e., 2.7 g/L), and low sulfide (not detectable) concentrations were detected in the bulk medium flowing through both flow cells. It is then possible to conclude that the bulk medium conditions, exhibited in the two different flow cells, are very similar as expected (identical medium was flowing through both flow cells) proving that the further differences found could be attributed to the nature of the inoculations. The first inoculation at the beginning of the second test stage (te 5 792 hours) led to an increase of cell density, a decrease in sulfate concentration linked to an increase in sulfide concentration due to the enhanced sulfidogenic metabolic processes. However, no significant modifications were observed in the electrochemical response after this first inoculation: 1/(Rp/“Ω) remained stable with low values (Fig. 10.42). This stable trend in corrosion currents could be attributed to the corrosion product layer that remained stable even with the perturbation of the medium. In addition, sulfidogenic bacteria could enhance protective layer properties by promoting the formation of protective iron sulfide.

10.6 Remedy of microbially influenced corrosion An inhibitor is a substance that is added in a small quantity in a corrosive environment with the purpose to retard corrosion reaction by forming a protective film. The inhibitors

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FIGURE 10.41

Oxygen concentration in parts per million (c(O2)/ppm) and pH evolution of bulk media in flow cell A (inoculation with Desulfovibrio alaskensis) and flow cell D (inoculation with Desulfovibrio desulfuricans) during the whole test (Stipaniˇcev et al., 2013).

have found numerous applications. These serve as effective agents to protect in-service (Fig. 10.43). Because of the increased environmental consciousness and strict legislation over the past years, there has been a rising trend to use alternate green approaches characterized by minimum environmental burden. These work on the principles of green chemistry, which include waste prevention, atomic economy, reduced hazardous chemical synthesis, designing safer chemicals, safer solvents and auxiliaries, design for energy efficiency, use of renewable feedstocks, reduce derivatives, use catalysts rather than stoichiometric reagents, design for degradation, real-time pollution prevention, and safer chemistry for accident prevention. Green corrosion inhibitors as an effective environmentally friendly technique have attracted more attention in recent years. Several common sources of green inhibitors include plant extracts, pharmaceutical drugs, ionic liquids, and synthetic inhibitors are the common sources of eco-friendly corrosion inhibitors. Plants (i.e., extract and oils) are the essential source of the extensive range of green corrosion inhibitors in different acidic media due to their versatile physical, chemical, and biological properties. Other advantages of plants as the sources of corrosion inhibitors include low-cost, plentiful availability, and their biodegradability. Plants are well known as a rich source of natural chemical compounds that can be readily extracted with low-cost and minimum environmental

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FIGURE 10.42 Average instantaneous corrosion rate (1/(Rp/”)) and OCP (E(OCP)/V (vs SCE)) values with standard deviation error bars for 12 o’clock positioned steel specimens (WE) exposed in flow cell A (inoculation with Desulfovibrio alaskensis) and flow cell D (inoculation with Desulfovibrio desulfuricans) during the 2200 h of test (Stipaniˇcev et al., 2013).

FIGURE 10.43

Available corrosion protection methods in the industry.

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10. Corrosion and its mitigation

pollution. Ionic liquids are also green solvents composed of ions that can dissolve different types of inorganic and organic compounds. The ever-increasing application of ionic liquids in almost all fields of chemical engineering results from their attractive properties which have nominated them as eco-friendly chemicals. Concerning the use of drugs as a source of green corrosion inhibitors, they are substances with relatively complex structures composed of natural or synthesized constituents. Drugs derived from natural sources have attracted more attention in recent years to be used as corrosion inhibitors. In addition, the tendency to use expired drugs as corrosion inhibitors increasing because it can diminish their disposal cost and environmental pollution. Numerous environment-friendly inhibitors have been explored over the past decades, and from time to time these have been reviewed. In 2011, Gece (2020) reviewed drugs as corrosion inhibitors with a focus on efficiency. Two more reviews highlighting the importance of biopolymers and surfactants in various corrosive media were published in 2011. In 2012, Rani and Basu presented progress on the application of natural materials as green corrosion inhibitors in different corrosive environments. Verma et al. in 2017 reviewed the corrosion inhibition performance of ionic liquids. Over the past five years, substantial progress has been made in various classes of green inhibitors. The present article puts together the latest developments in all these areas followed by a short discussion on this rapidly emerging multidisciplinary field. This review focuses on several classes of natural and synthetic substances as green corrosion inhibitors specifically for steels in acidic media. These include plant extracts, ionic liquids, amino acids, drugs, polymers, and rare-earth elements. These follow most of the principles of green chemistry as mapped in Table 10.22. TABLE 10.22 Evaluation of inhibitors in accordance with 12 principles of green chemistry. Plant extracts Waste prevention

Ionic liquids

Amino acids

ü

Natural polymers

Lanthanide Drugs salts

ü

ü

ü

Atom economy

ü

Less hazardous chemical synthesis

ü

ü

ü

ü

Designing safer chemicals

ü

ü

ü

ü

Safer solvents and auxiliaries

ü

ü ü

Design for energy efficiency Use of renewable Feedstocks

ü

ü

ü ü

ü

Reduce derivatives

ü

ü

ü

ü

ü

Catalysis Design for degradation

ü

Real-time pollution prevention

ü

Safer chemistry for accident prevention

ü

ü

ü

ü

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FIGURE 10.44 Distribution of the research works performed from 2014 to 2019 on Green Inhibitors for steels in acidic media.

Wei et al.’s (2020) review mainly covers important corrosion inhibitors of each class, inhibition mechanisms along with governing isotherms, and the influence of various factors on inhibition efficiency. The presented information is derived from 154 articles published in the past 5 years accessed from all important databases. The effort spent on various classes of inhibitors is shown in Fig. 10.44. Judged by the publication volume, the efforts can be ranked as plants followed by natural polymers and ionic liquids. This review aims to provide a comprehensive understanding of green inhibitors and a comparison basis to guide a suitable and economical inhibitor’s selection for a particular situation. Applying corrosion inhibitors into the corrosive media results in their adsorption on the active sites (higher energy regions) of the metal surface followed by the formation of a protective film. This layer isolates the metal surface from the aggressive environment thereby preventing it from corrosion. In comparison with inorganic inhibitors, metal surface passivation through organic inhibitors possesses several advantages. For instance, organic green inhibitors can passivate the surface uniformly resulting in the highest possible protection, whereas passive layers from inorganic inhibitors are very brittle, making the metal surface susceptible to local corrosion attack (pitting, crevice). The adsorption of inhibitors may take place either through physical adsorption or chemical adsorption or synergic action of the two (i.e., mixed mode). The interaction between inhibitors molecules and metal surface in either of these two modes depends on the surface charge of the substrate. The electrostatic interaction of charged inhibitors with the oppositely charged metal surface results in the adsorption of inhibitors on the metal surface regarded as direct physical adsorption. However, electrostatic interaction of pre-adsorbed ions (e.g., halide ions in amino acids) and negatively charged surfaces will result in indirect adsorption. Adsorbed anions on the metal surface lead it to be negatively charged thereby increasing its capability to adsorb protonated inhibitors. This phenomenon may specifically occur in acidic media. However, in the case of zero-charged metal surfaces (ZPC), none of the cations or anions could be adsorbed on the surface. Therefore, the adsorption of inhibitors will take place through a chemical reaction between inhibitor molecules and metal surfaces. Inhibitors are generally electron donators establishing donor
acceptor interaction such that the unshared electron pairs of heteroatoms (e.g., O, N, and S) or p-electrons of the aromatic ring of inhibitors interact with d-orbitals of the atomic surface of the metal steel structures such as boilers, heat exchangers, and oil, gas, containers from corrosion. Metals and steels, in particular, are commonly exposed to acidic media before

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carrying out a process (e.g., welding or coating). Similarly, acidification of corroded structures (e.g., oil wells, oil tankers, heat exchangers, pipelines) is performed to remove corrosion products. The use of inhibitors during these necessary treatments has demonstrated promising results in inhibiting the corrosion reactions and the associated metal damage. Several essential considerations determine the selection of inhibitors. One of the key factors is the toxicity of the inhibitor. In general, the high volatility of toxic traditional inhibitors, such as chromates, phosphates, and nitrates results in the release of toxic gases thereby adversely affecting the environment. Table 10.23 lists plant extracts for various applications of MIC prevention (Table 10.24). TABLE 10.23 Plants extracts as corrosion inhibitors for steels in acidic media: starting from the latest discovery. Plant extract

Type of inhibitor

Type of solution

Type of steel

Efficiency (%)

Adsorption mechanism

Rosa canina fruit extract

Mixed

HCl

Mild steel

86

Chemical adsorption

Citrullus lanatus fruit extract

Mixed

HCl

Mild steel

91

Chemical adsorption

Chinese gooseberry fruit shell extract

Mixed

HCl

Mild steel

92

Physical adsorption

Cissus quadrangularis plant extract

Mixed

HCl

Mild steel

NG

Both physical and chemical adsorption

Borage flower aqueous extract

Mixed

HCl

Mild steel

91

Chemical adsorption

Pineapple stem extract

Mixed

HCl

Carbon steel

97.6

Chemical adsorption

Tamarindus indica aqueous extract

Mixed

HCl

Mild steel

93

Both physical and chemical adsorption

Lagerstroemia speciosa leaf extract

Mixed

HCl

Mild steel

94

Both physical and chemical adsorption

Eriobotrya japonica lindl leaves extract

Mixed

H2SO4

Mild steel

92.7

Both physical and chemical adsorption

Pigeon pea leaf extract

Mixed

HCl

Mild steel

91

Physical adsorption

Tragia involucrate L (T. involucrate L)

Mixed

HCl

Low carbon steel

87.54

Both physical and chemical adsorption

Ircinia Strobilina crude extract

Mixed

H2SO4/HCl

Mild steel

92.0

Both physical and chemical adsorption

Parsley (Petroselinum sativum) extract

Mixed

HCl

Mild steel

92.39

Physical adsorption

Aqueous peganum harmala seed extract

Mixed

HCl

Mild steel

95

Both physical and chemical adsorption

Elaeis guineensis leaves extract

Mixed

HCl

Mild steel

73.81

Physical adsorption

Loquat leaves extract

Cathodic

H2SO4

Mild steel

89.06

Chemical adsorption (Continued)

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TABLE 10.23

(Continued)

Plant extract

Type of inhibitor

Type of solution

Type of steel

Efficiency (%)

Adsorption mechanism

Groundout leaves extract

Mixed

H2SO4

Mild steel

86.03

Physical adsorption

Costus afer, Uvaria chamae, and Mixed Xvlopia Ethiopia

HCl

Mild steel

83.7/84.6/ Physical adsorption 87.0

Lemon balm extract

Mixed

HCl

Mild steel

95

Chemical adsorption

Ficus religiosa

Cathodic

H2SO4

Mild Steel

92.26

Both physical and chemical adsorption

Glycolipid biosurfactant

Mixed

CH3COOH

Carbon steel

87

Physical adsorption

Cuscuta reflexa extract

Mixed

H2SO4

Mild steel

95.47

Both physical and chemical adsorption

Myristica fragrans extract

Mixed

H2SO4

Mild steel

87.81

Both physical and chemical adsorption

Sida cordifolia extract

Mixed

H2SO4

Mild Steel

80.17

Physical adsorption

Armoracia rusticana

Mixed

H2SO4

Mild steel

95.74

Both physical and chemical adsorption

Tilia cordata extract

Mixed

HCl

Carbon steel

84.34

Physical adsorption

Fenugreek leaves extract

Mixed

H2SO4

Mild steel

89.06

Physical adsorption

Gorse aqueous extracts

Mixed

HCl

Mild steel

96.6

Chemical adsorption

Aquilaria subintegra leaves extracts

Mixed

HCl

Mild steel

93

Physical adsorption

Lannea coromandelica leaf extract

Mixed

H2SO4

Mild steel

93.8

Physical adsorption

Iota-carrageenan and inulin biopolymers

Mixed

H2SO4

Mild steel

97.37

Chemical adsorption

Morus alba pendula leaves extract

Mixed

HCl

Carbon steel

96

Chemical adsorption

Papaya seed

Mixed

H2SO4

Carbon steel

90

Physical adsorption

Funtumia elastic

Mixed

H2SO4

Mild steel

97.8

Physical adsorption

Citrus aurantium leaves extracts Mixed

H2SO4

Mild steel

89

physical adsorption

Diospyros kaki (Persimmon) Leaves

Mixed

HCl

St37 steel

91

Both physical and chemical adsorption

Green leafy vegetable extracts

Mixed

HCl

Carbon steel

86

Physical adsorption (Continued)

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TABLE 10.23 (Continued) Type of inhibitor

Type of solution

Type of steel

Efficiency (%)

Extract of Eucalyptus globulus leaves

Mixed

H2SO4

Carbon steel

84

Both physical and chemical adsorption

Nicotiana tabacum leaves extract

Mixed

H2SO4

Mild steel

94.13

Chemical adsorption

Extract of Tagetes erecta (Marigold Flower)

Mixed

H2SO4

Mild steel

96

Physical adsorption

Extracts Chenopodium Ambrosioides

Cathodic

H2SO4

Carbon steel

94

Chemical adsorption

Plant extract

Adsorption mechanism

TABLE 10.24 Essential oils as corrosion inhibitors for mild steel in acidic media. Type of steel

Type of inhibitor

Inhibitor concentration

Acidic media

Efficiency (%)

Carbon steel

Clove seed aqueous extract

1M

HCl

93

EIS, PP, SEM, AFM, MD, DFT

25

Mild steel

Artemisia herba-alba oil

0.5 M

H2SO4

88

GC, GC/MS

30, 40, 50, 60,

Mild steel

Ultrafiltrated alkaline organosolv oil palm fronds lignin Artemisia Mesatlantica essential oil

0.5 M

HCl

EIS, PDP, WLM

30

1M

HCl

87 83 81 92

PDP, EIS, SEM, XPS

30

304 Stainless steel

Red pepper seed oil

1M

HCl

92.32

FTIR, PDP, EIS

25, 35, 45, 55, 65

Mild steel

Adenopus breviflorus seed oil

0.5 M

HCl

94.22

SEM, FTIR, NMR

25, 35, 45

Mild steel

The essential oil of Salvia aucheri mesatlantica

0.5 M

H2SO4

86.12

GC, GC/MS, EIS, PDP, WLM

25

Carbon steel

Test methods

Conditions ( C)

AFM, Atomic force microscopy; DFT, dynamic functional theory; EIS, electrochemical impedance spectroscopy; FTIR, Fouriertransform infrared spectroscopy; GS, gas chromatography; MD, molecular dynamic; MS, mass spectrometry; NMR, nuclear magnetic resonance spectroscopy; PDP, potentiondynamic polarization; SEM, scanning electron microscope.

Oils as plant extracts have drawn substantial attention from researchers. Essential oils, also known as volatile or ethereal oils, are concentrated hydrophobic liquids that contain monoterpene, sesquiterpene hydrocarbons, and oxygen-doped groups such as alcohols, aldehydes, ketones, acids, phenols, oxides, lactones, ethers, and esters. Over the past decades, many research works have been performed to assess the corrosion inhibition performance of natural oils for several metallic alloys in neutral, acidic, and alkaline media. The

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TABLE 10.25 Bacteria

807

Microbes involved in corrosion and its classification. Sulfur oxidizing bacteria APB (inorganic Sulfur acid by Acidothiobacillus, organic by Bacillus sp.) Sulphate reducing bacteria Slime producing bacteria Iron reducing bacteria

Fungi

Aspergillus Niger Penicillium cyclopium

Algae

Blue-green algae

first attempt to use oil as an inhibitor was made the 1960s (Wei et al., 2020). Initially used was vegetable oil together with molasses to inhibit steel corrosion in the acid pickling process. Later, the trend of using natural oils as inhibitors became popular leading to several successful discoveries such as Ginger, Henna, Jojoba, and Artemisia oil The main bacteria involved in the corrosion of mild steel, cast iron, and stainless steel are sulfur-oxidizing bacteria, SRB, manganese-oxidizing bacteria, iron-oxidizing/reducing bacteria, etc. These microbes stimulate corrosion in several ways. These microbes coexist in naturally arising biofilms, frequently developing synergistic consortia. During microbial corrosion, the microbes initiate, facilitate and aggravate corrosion through cooperative metabolism and then develop a biofilm on the metal surface. Material and microbe interactions cause the bacteria to adhere and form a biofilm. Biofilm consists of 95% water with Extracellular Polymeric Substance (EPS) and inorganic matter/cell suspension. The environmental factors strongly affect the development of microbial community within the biofilm. Biofilm is also responsible for transforming the properties at the metal/solution interface. The microbes involved in the corrosion process are listed in Table 10.25. Microbial Corrosion in MetalsMicrobes can directly or indirectly disturb the integrity of many metals used in industrial applications. Most of them including copper, iron, nickel, aluminum, and their alloys, are more or less vulnerable to damage. Only titanium and its alloys appear to be usually resistant [19]. SRB are a major bacterial group involved in MIC. The role of SRB in iron corrosion can be divided into direct corrosion and indirect corrosion. Indirect corrosion is the chemical attack by hydrogen sulfide or other acidic organisms. Direct corrosion uses the consumption of cathodic hydrogen and iron-derived electron transfers. However, when outer polarization is applied, the interaction between polarized electrode and SRB metabolic activity should not be ignored. The electron transfer pathways between SRB and polarized electrodes can be viewed from two categories: mediated electron transport (MET) that utilizes redox-active chemical mediators and direct electron transfer (DET) that relies on specific protein-based structures or nanowires of bacteria (Fig. 10.45). Dissolved hydrogen is an electron mediator used by SRB as an electron carrier. Studies found that cathodically produced hydrogen at proper potential values facilitated the growth of hydrogenase-positive bacteria (Table 10.26).

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ee- e

H

H+

H

Sulfate reduction under biocatalysis

Enzyme

H2

H

e-

Periplasm Cytoplasm SO42-

MET

HS-

H2/H

Energy release

H

eee-

Periplasm Cytoplasm SO42-

Med(ox)

e-

Med(red)

HSEnergy release

eFe

e- ee-

Sulfate reduction under biocatalysis

Enzyme

e-

Periplasm Cytoplasm SO42-

Pilus

Pt

Sulfate reduction under biocatalysis

DET

HS-

e-

Energy release

e-

Periplasm Cytoplasm SO42-

eee-

Cyt

Sulfate reduction under biocatalysis

HSEnergy release

eFIGURE 10.45 Schematic representation of the interaction between cathodic protection and activity of sulfatereducing bacteria (Guan et al., 2016).

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TABLE 10.26

Factors correlating with sulfate-reducing bacteria (SRB) numbers for buried pipeline sites.

Factor

Correlation coefficient

Range

Bacterial numbers (acid-producing bacteria)

0.829

103
108 cells/g wet soil

Total organic carbon in groundwater

0.645

0.05%
1.2%

Soil resistivity

20.642

500
30,000 Ω cm

Soil water content

0.626

5%
36%

Soil oxidation/reduction potential

20.545

2316 to 384 mV (CSE)

Sulfate in groundwater

0.455

0.3
200 mg/g wet soil

Clay

0.407

N/A



CSE, Copper
copper sulfate electrode. From Jack (2002).

TABLE 10.27 Indicator minerals found as corrosion products in various corrosion scenarios seen in pipeline excavations and laboratory soil box tests.

Corrosion scenario

Corrosion products (color, chemistry, mineral form)

Corrosion rate, mm/ year

Simple corrosion processes Abiotic aerobic corrosion (O2 is the electron Yellow/orange/brown/black iron (III) oxides, acceptor, X, in cathodic reaction, Eq. 2) including lepidocrocite, goethite, magnetite, maghemite, hematite

0.04
0.2

Abiotic anaerobic corrosion (H1 as X in cathodic reaction, Eq. 2)

Pasty or dispersed white iron (II) carbonate (siderite)

0.002
0.01

Anaerobic MIC (SRB with biotic iron sulfide as X, Eq. 2)

Black, finely divided iron (II) sulfides, including amorphous iron sulfide, mackinawite, greigite

0.2 general

Aerobic - anaerobic MIC (SRB/“FeS”)

Iron (II) sulfides, including marcasite and pyrite

...

Anaerobic MIC (SRB/“FeS”) - aerobic

Elemental sulfur, iron (III) oxides 1 residual anaerobic corrosion products

2
5a

0.7 pitting

Secondary transformations involving MIC

a

This very high corrosion rate may not be sustained beyond the period of secondary oxidation of the anaerobic site. From Jack (2002).

Table 10.27 summarizes conditions that correlate with elevated SRB populations. Based on correlations of this sort, predictive models have been developed to prioritize maintenance activities in particular areas. A summary of corrosion products indicating different corrosion scenarios is given in Table 10.2.

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TABLE 10.28 Factors for the diagnosis of microbially influenced corrosion scenarios in cooling water systems. Microorganism (metabolite) Corrosion morphology

Specific corrosion products and deposits

Active MIC Sulfate-reducing bacteria (sulfide)

Clustered hemispherical pits on stainless steel, Carpenter 20, aluminum, and carbon steel. Rare on titanium. Copper poorly defined Very irregular pit surface in less noble metals

Acid producers (lower-pH organic acids for acidproducing bacteria)a

Corrosion is localized, moderate Striations in None stated steel under tubercles, as for preferential acid dissolution of microstructure in rolling direction

Metal sulfides present Voluminous, brown, friable tubercles of iron (III) oxides over pit

Passive MIC Slimers (gelatinous mass with high microbial numbers)

General corrosive attack under slime Pitting if SRB present

Rusting may color surfaces brown

a Acid producers are often associated with SRB but outnumber them in this case. Organisms such as Clostridia, Thiobacillus, and Nitrobacter are cited as potential acid producers.

The following four factors in the identification of corrosion as MIC were looked for the following factors: • • • •

Presence of microorganisms or their byproducts Microbiologically unique corrosion morphology Specific corrosion products and deposits Compatible environmental conditions

The use of these factors for diagnosis of MIC scenarios in cooling water systems is addressed in Table 10.3 (Table 10.28). Literature reports identify several possible MIC scenarios on stainless steel weldments. Table 10.29 summarizes the organisms and features that may be useful in failure analysis. Biocorrosion may be prevented by reducing biofilm formation on the surface of the metal. Biocides and a few dispersive agents are applied to the metal surface to reduce the formation of biofilm as a part of chemical treatment. Nevertheless, these treatments have lost their applications due to the environmental concerns. Therefore, development of ecofriendly inhibitors is drawing attention in recent years [12]. During the 1960s and the early 1970s, the research on MIC was devoted to objection or verification of the anaerobic iron corrosion provoked by SRB. The researchers focused on the explanation of MIC mechanisms by the cathodic polarization theory. The hindrance of the appropriate knowledge transfer among the different specialists explains the difficulty in reaching an adequate understanding of MIC. In the 1980s, which brought significant progress in understanding MIC, several research groups carried out intensive work to elucidate the MIC mechanisms. An increasing intellectual and technical cross-fertilization of ideas elaborated by microbiologists, materials

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TABLE 10.29 Microbially influenced corrosion scenarios that may play a role in the corrosion of weldments in stainless steel. MIC by

Mechanism

Indicators

Manganese oxidizers

Ennoblement of stainless steel potential due to MnO2

Elevated manganese-oxidizing organisms, manganese, and possibly chloride in deposits

SRB primary

Sulfides, SRB facilitate chloride attack in anaerobic systems

Dark-colored corrosion products, with iron sulfide, chloride, and a high ratio of Fe21/Fe31; near-neutral pH

SRB secondary oxidation

Pitting stabilized by thiosulfate formed by oxidation of sulfides

Cyclic anaerobic, aerobic conditions; surface of corrosion products in pit oxidized red, orange, or brown

Ironoxidizing bacteria

Decrease of pH by oxidation of Fe21 to Fe31 in pits

Red/orange corrosion products rich in Fe31; iron-oxidizing organisms such as Gallionella; pH acidic

scientists, electrochemists improved the understanding of MIC. The 1990s brought a breakthrough in knowledge of MIC. The tardiness was not only due to the lack of cooperation among specialists (chemists, microbiologists, and metallurgists) but to the lack of special instrumentation that could measure the destructive activity of microbes involved in a biofilm. The 21st century resulted in the further development of new analytical methods applicable either in laboratory or in industry. One of the most exciting advances in instrumentation that appeared in these years is the chemical/biochemical microsensors that can analyze the changes in the oxygen level, in the pH value and in the concentration of different metabolites within the biofilm. Although the MIC is of electrochemical nature, the participation of microbes in these undesired reactions alters the metal-solution interface by the formation of biofilms. A substance that when added to a corrosive solution in a small concentration causes a reduction in the corrosion rate is known as an inhibitor. Such inhibitors are more common for preventing MIC. They target the bacteria and destroy the microorganisms involved. Just like antibiotics used in the pharmaceutical industry, most frequently used corrosion inhibitors include synthetic chemicals such as inorganic and organic compounds. These synthetic chemicals are costly and harmful to the environment. As such, none of these products passes the sustainability test. This fact has been recognized for sometime and efforts have been made to introduce natural products (Al-Darbi et al., 2002). The first eco-friendly green inhibitor (Chelidoniummajus) was applied in the 1930s and it showed better performance than chemical inhibitors (Miralrio and Espinoza Va´zquez, 2020). The plant extracts compiled by Miralrio and Espinoza Va´zquez (2020) show corrosion inhibition efficiencies above 60%, most of them around 80%
90%. The effect of concentration, extraction solvent, temperature, and immersion time was studied as well. Additional studies regarding plant extracts as corrosion inhibitors on metals are needed to produce solutions for industrial purposes. Here, note that extracted materials is not necessarily natural as the extraction process would render them unnatural (Fig. 10.46). All plant parts—leaves, flowers, seeds, fruits, roots, and stems—are used to obtain the extracts. In brief, extraction methods are based on heating, cooling, and separating the active compounds in the presence of the solvent. Secondly, traditional extraction methods

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Leaf

Anthocyanins Flavones Sinapyl esters Isoflavonoids Psoralens

FIGURE 10.46

Various chemicals can be extracted from natural sources, but the extraction process dictates the eventual natural status of the material.

Flower - Coumarin

Fruit Flavonoids Saponins Alcaloids Sterolds Flavonoids Saponins Alcaloids Sterolds

Tricarboxylic acid Terpenoids Tannins Flavonols Aromatic acids

Stem

Roots

can be summarized in maceration, infusion decoction, digestion, and percolation (Fig. 10.47). In general, the form of the extract method is applicable on the basis of what is desired to be obtained. In maceration, crushed, smashed, or cut materials, sometimes previously dried, are immersed in the extraction solvent for periods of at least 3 days in constant agitation (Fig. 10.47A). The diffusion of the solvent in the targeted material solubilizes the active compounds, leading to their possible extraction. The solids suspended in the resulting mixture can be separated by filtering. For this method, the advantage is that all the essence is extracted without altering it, and the active ingredients are easily soluble. The infusion method yields the extract by means of maceration for a short period of time in the presence of boiling water. Thus, the most soluble constituents are solubilized, passing to the extract. Similarly, in the decoction process, the crude drug is boiled in a specific volume of water for a defined time (Fig. 10.47C). The digestion method proposes the maceration of the raw materials in the presence of a slightly warm solvent, improving the solubility of the extraction solvent and preserving the active compounds from decomposition (Fig. 10.47). Percolation is a filtration method, at room temperature, in which the moistened raw material is placed in a conical vessel, the percolator, with an adjustable closure (Fig. 10.47B). Then, the percolator must be filled with solvent and covered up, obtaining the extract drop by drop. The advantages of percolation lie in the high performance of active substances, in the short time required for their manufacture, and in the economy of the materials used. More sophisticated methods are hot continuous extraction and ultrasound extraction or sonication The first one uses the Soxhlet apparatus, formed by a glass body with boiling

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(A)

813

(B)

stirrer vessel

Vessel

Solvent

Solvent

Crushed or cut raw material

Crushed or cut raw material Drain valve Perforated plate

(C)

Stirrer Vessel

Extraction solvent & raw material mixture Drain valve Heater plate (D)

Condenser

(E)

Transducer

Siphon

Porous thimble Sample

Ultrasonic probe

Stirrer

Extraction mixture Solvent & Extract Heater plate

Heater plate

FIGURE 10.47 Diagrams of common extraction methods: (A) maceration, (B) percolation, (C) decoction, (D) Soxhlet, and (E) sonication Modified from Miralrio and Espinoza Va´zquez, 2016. Pipelines

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flask, a siphon arm, thimble, extraction chamber, and condenser (Fig. 10.47D). In brief, the boiling flask containing the solvent is heated and the vapor produced is condensed. The resultant liquid falls into the thimble containing the raw material, and the extract fills the extraction chamber up in order to put into function the siphon arm to return the liquid into the boiling flask. The reflux process must be stopped to obtain the degree of extraction desired. Finally, sonication is a technique that uses high-energy ultrasounds to improve the permeability of cell walls, producing cavitation to disrupt cellular membranes (Fig. 10.47E). Consequently, sonication breaks the cells, releasing their content for further extraction. Liquids obtained by the methods introduced above are then clarified by filtration or decantation. The solvent has a key role in the extraction methods since it is responsible for solubilizing the active compounds when it diffuses through plant tissues, making their extraction possible. Extraction solvents have been shown to affect the physical, chemical, and antioxidant properties of the extracts obtained, as the concentration of flavonoids, saponins, phenolic compounds, and others present in plant extracts vary according to the extraction solvent. Consequently, various solvents have been used to obtain the desired concentration of active compounds from plant extracts. Then, the efficient extraction of active compounds depends on the solvent used, among which the most common are water, methanol, ethyl acetate, dichloromethane, and hexane [54,55,56]. Water could be the most convenient extraction solvent, since it is highly available, nontoxic, nonflammable, and inexpensive. Not all plant extracts can be obtained as aqueous extracts, giving the chance to test other solvents. Thus, solvents are selective and, in order to obtain the optimal yield, several options must be tested. Other important parameters for the extraction process are drying and extraction temperatures. The first one marks the temperature to get the plant dry, although room temperature is commonly used since plants are usually dried in the shade. The use of dried plants has benefits, being suitable for long storage and with reduced weight. In contrast, the drying process has been shown to affect the stability of bioactive compounds and the antioxidant capacity. Fresh plants can be used instead of dried ones, although their use could produce some drawbacks as well. Fresh plants could be subject to degradation by solar radiation, and some of their constituents could be easily evaporated or oxidized. However, in some cases, phytochemicals could be extracted in higher concentrations from fresh samples instead of dried ones. The extraction temperature is another important parameter since a high temperature promotes the decomposition of phytochemicals and a lower one reduces the solubility of active compounds and hinders its extraction. Achieving the optimal concentration of phytochemicals requires the correct choice of extraction temperatures, extraction cost, solvent, and others (Table 10.30). Oblivious to the lack of long-term sustainability, authors conclude that the most important challenge is to have an extract or to isolate the main component that has an inhibition efficiency greater than 90% according to the norm NRF-005-PEMEX-2009. It is very likely that these products will not be sustainable, having lost their innate properties during the extraction and refining process. A variety of green organic compounds are known to show excellent properties in shielding metal surfaces against corrosion.

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TABLE 10.30 Theoretical characterization performed for several plant extracts: plant, main extract constituents, and theoretical framework used for their evaluation. Plant

Extract constituents

Dioscorea septemloba

Dioscin, β-sitosterol, dioscorone A, and palmitic acid

Eucalyptus

Macrocarpal E, macrocarpal A, eucalyptome, and ellagic acid

Eucalyptus globulus Eucalyptol, globulusin-A, and globulusin-B Ficus tikoua

Allantoin, 5-methoxypsoralen, methyl caffeate, and methyl 4-hydroxycinnamate

Juglans regia

Coumaric acid, ferulic acid, syringic acid, vanillic acid, juglone, and myricetin

Glycyrrhiza glabra

Licochalcone A, licochalcone E, liquiritigenin, 18β-glycyrrhetinic acid, glycyrrhizin, and glabridin

Rosa canina

Ascorbic acid, marein, pectin, and tannin

Saraca ashoka

Epicatechin

Tamarindus indica

Apigenin, naringenin, eriodyctoyl, and taxifolin

Tamarindus indica

Naringenin, apigenin, eriodictyol, and taxifolin

Ziziphora

Acacetin, chrysin, and thymonin

In general, Green Chemistry Initiatives (GCIs) include various biodegradable and natural materials such as plant extracts, natural honey, herbs, oil, and drugs. A number of synthetic GCIs have also been reported in the literature, like surfactants and ionic liquids, which are out of the scope of this review. Fig. 10.48 presents some of the natural materials used as GCIs in corrosion studies (Verma et al., 2018). It is worth adding that the amounts of phytochemicals present in the extract are also affected by a number of factors, including the plant’s age, vegetative cycle, geographic region, and the impact of weather conditions. Besides, there are extract powders that are commercially available and can be used in the preparation of inhibitor stock solutions. Some of the commonly used extraction processes along with their advantages are presented in Table 10.31. Besides, a typical experimental procedure for yielding the Chamomile extract in powder form is shown schematically in Fig. 10.49 (Tables 10.32 and 10.33). The effectiveness of GCIs in preventing corrosion is determined by their adsorption properties on metal surfaces. Previous studies have found that factors impacting GCI inhibition efficacy are mostly defined by their concentration, structure, exposure time, and testing temperature. An increase in GCI concentration leads to a concurrent reduction in corrosion rate and an improvement in inhibition efficiency until it reaches a specific concentration (optimum level). Classification of the eco-friendly green corrosion inhibitor is shown in Fig. 10.50. Lavanya makes several interesting comments about natural means of corrosion inhibition. Each of these comments emerges from an inherent false premise, which is listed below.

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FIGURE 10.48 Natural materials used as green corrosion inhibitors (Verma et al., 2018).

Plant Extracts

Oleochemicals

Drugs

Natural Gums

Carbohydrates

Amino Acids

Bio-Surfactants

Bio-Polymers

TABLE 10.31 Some extraction processes for plant extracts (phytochemicals) and their benefits. Method

Advantage

Note

Solvent extraction

Improved energy efficiency, high production output, and fast and easy operation

The most commonly used technique among others. Operation factors affecting the properties of extract include type of solvents, solvent-to-solid ratio, extraction time, and temperature

Microwaveassisted extraction

Enhanced reaction efficiency, reduced reaction durations, and minimized active component damage

Irradiation with microwaves has a synergistic impact of both breaking and heating, while other methods do not have such capability

Enzymeassisted extraction

Suitable method for releasing bounded substances, Allowing for the utilization of practically the increased overall yield entire plant matrix

Ultrasoundassisted extraction

Higher extraction yield, reaching almost 99.99% in some studies. Without posing any damaging effects on the structure of phytochemicals

Ultrasonic energy-assisted extraction aids the leaching of organic and inorganic components. Ultrasound energy causes severe bubble collapse, assisting diffusion into the plant matrix, which in turn enhances efficiency

Chemical inhibitors play an important role in the protection and mitigation strategies for retarding corrosion (Gece, 2011). The most effective and efficient inhibitors are the organic compounds that have p bonds, heteroatoms (P, S, N, and O), and inorganic compounds, such as chromate, dichromate, nitrite, and so on. However, the use of these

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Filtration 3 h, 70 °C OH OH

Added to water

O

OH

OH

H3CO

Centrifusion

O

O

O

Quercetin

Herniarin OH H

powder

α-farnesene Drying

α-bisabolol

Start

Heating

Chamomile extract

Chamomile FIGURE 10.49 Sequence of experimental steps for the preparation of Chamomile extract together with its major constituents and corresponding molecular structures. (From Zakeri et al., 2022).

compounds has been questioned lately, due to the several negative effects they have caused on the environment. Thus, the development of the novel corrosion inhibitors of natural source and nontoxic type, has been considered to be more important and desirable. Because of their natural origin, as well as their nontoxic characteristics and negligible negative impacts on the aquatic environment, drugs (chemical medicines) seem to be ideal candidates to replace traditional toxic corrosion inhibitors. The inclination toward eco-friendly corrosion inhibitors development intersects across several goals of pharmaceutical research, one of which is to discover or develop molecules

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TABLE 10.32 Some functional groups found in the GCIs. Functional Group

Name

Functional Group

Name


OH

Hydroxy


S


Sulfide


COOH

Carboxy


NH

Imino


C
N
C


Amine


C
O
C


Epoxy


CONH2

Amide


P


Phospho


N 5 N
N


Triazole


NO2

Nitro


NH2

Amino


SH

Thiol

TABLE 10.33 Contemporary narrative and its deconstruction. Statement

Discussion of underlying premise

Correct premise

Implication

Plant extracts are of low protection efficiencies at relatively higher concentration

This observation is false. Also, there is no basis for comparing efficiency of natural vs. unnatural inhibitors as they are on the opposite side of the sustainability spectrum. There is no equivalence in concentration values of natural and artificial

Concentration should not be a factor if only one of them is sustainable

Comparison should not be made based on concentration of “active ingredient,” a natural substance has a different level of effective concentration

One of the greatest challenges of using organic extracts as corrosion inhibitors is their limited solubilities, especially at their higher concentration

It assumes that natural materials behave the same way as synthetic materials. This is not true

Natural materials, in their innate form, do not require high concentration to be effective

A different standard is warranted for natural inhibitors

Difficulty of plant extracts for mitigating corrosion is that extract preparation is highly tedious as it involves several steps

Extraction process is assumed to be necessary

Extraction of “active Natural materials should be ingredients” makes the used directly and if they are process unsustainable refined, the process must be wholly sustainable

Using organic solvents for extraction may harm the environment

False premise

Organic solvents are not sufficient if they are obtained following an unsustainable process.

Standards must be revised for organic/natural materials

Application of complex organic molecules, such as ionic liquids and drugs as corrosion alleviating agents is restricted because its synthesis is extremely expensive

Assumes that organic and synthetic materials are interchangeable

There is no need for using synthetic chemicals. They are not sustainable

Natural products should be used in their natural state

(Continued)

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TABLE 10.33

(Continued) Discussion of underlying premise

Correct premise

Implication

Application of rare-earth elements for protection of metals against corrosion is limited by some shortcomings. It is very difficult to separate rareearth element one from another. This discloses the limitation of applied technology.

Assumes that refined rareearth materials are necessary and useful

Rare-earth metals are useful only in innate form

Rare elements have great potentials in inhibiting bacteria growth. However, they have to be used in their native form, rather than refined form

The extraction procedure includes the production of a lot of waste such as ammonia, acids and some radioactive elements, which can possibly disturb the environment if not treated properly.

Assumes that the extraction process must involve synthetic (hence unsustainable) chemicals

Products out of natural extraction process are not harmful to the environment

Further, rare-earth metals are unstable which may arise as a considerable problem in using those elements as corrosion inhibitors.

Rare-earth matters are not unstable in their native form.

Few of the extracts have the capacity to hinder microbial growth as they are very efficient reactive oxygen scavengers.

False premise

Statement

OGCIs reveal their These are valid protective action via assumptions only for chemisorption or synthetic materials physisorption onto metal/ solution interface by eliminating molecules of water on the metal surface for barrier film formation. Even though, plant extracts are of biological origin regardless of the aqueous and organic nature, are treated as environmentally benevolent however usually they are accompanied by low protection efficiencies at relatively higher concentration

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FIGURE

Polymers

10.50

Classification

of

green inhibitors.

Natural gums

Plant extracts

Green inhibitors Carbohydrate

Amino acid

Biosurfactant

Oleochemicals

with desired biological activity. Efforts to attain this goal are strongly driven by the notion of molecular similarity because in general similar molecules tend to behave similarly. Assigning an unknown molecule to the class of active or inactive molecules using an intermolecular similarity measure is known as virtual screening, and has already been emerged as a method to accelerate the discovery process of potential corrosion inhibitors. A table listing the 17 rare-earth elements, their atomic number and symbol, the etymology of their names, and their main uses is provided in Table 10.34. Some of the rare-earth elements are named after the scientists who discovered them or elucidated their elemental properties, and some after the geographical locations where they were discovered (Table 10.35). Few microbially induced corrosion studies carried out with various inhibitors are listed in Table 10.36. Al-Darbi et al. (2002) were the first ones to suggest entirely natural materials for preventing MIC, particularly caused by SRB. In that study, the influence of SRB, grown in a lactate/sulfate culture medium, on the corrosion of both uncoated and coated mild steel was evaluated in the presence and absence of natural additives. To achieve this, an oilbased coating (alkyd) was used with and without the addition of natural additives to protect mild steel in an SRB environment. Another objective of this study was to investigate the effects of SRB and/or their metabolites on the used coatings and the adverse effects of those coatings and additives on biofilm formation and bacteria growth rate. Two natural additives were identified for effective MIC protection. Natural products were selected based on the environmental appeal of the products. Two additives, derived from olive oil and Manhaden fish oil, were found to be effective in reducing MIC. In general, 2%
3% of a natural additive was deemed adequate for effective MIC protection. Bacteria populations were counted at the beginning and at the end of the tests using the plate count method. After immersing the different coupons for 3 months in the SRB medium, it was noticed that the number of bacteria and their colonies were highly affected by both the environment and the used coating systems.

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TABLE 10.34

Corrosion control ways (Poopla, 2019).

Control method

Description

Material selection

The sequential steps required in picking appropriate material include: preliminary selection, laboratory testing, laboratory result interpretation, economic analysis of apparently suitable materials and final selection. The finally selected material should have high mechanical strength, high corrosion resistance, and low cost.

Surface coating

This involves the use of anticorrosive protective coating to form a physical barrier between corrosive environments and material. It can be subdivided into metallic (a more noble layer of other metal used to coat the material) and nonmetallic (organic coatings such as paints, lacquers, and coal tar; and inorganic coatings such as porcelain enamels, chemical-setting silicate cement linings, glass coatings, and linings are being used to isolate the material from corrosive environment).

Excellent Equipment Design (EED)

EED enables application of novel design principles which put cost reduction, time, and future corrosion maintenance and repair into consideration. Typical examples of how EED can minimize corrosion include: avoiding dissimilar metal contact when electrolyte is present, avoiding crevice corrosion by joining different sections using welding rather than riveting, doubling section of the material under extreme degree of turbulence flow regime to avoid erosion
corrosion, avoiding equipment vibration, designing storage tanks for easy drainage, and so on.

Electrical protection

This could be classified as either cathodic protection (minimizes metal surface corrosion by making it the cathode of an electrochemical cell such that potential difference between anode and cathode is minimized simultaneously) or anodic protection (which is based on the principle of passivity executed by connecting material to be protected to an external d.c power supply positive pole).

Corrosion inhibitors

These are substances added in small concentrations/amount to a corrosive environment to reduce or stop electrochemical corrosion reactions occurring on a metal surface. They could be organic or inorganic based on their sources and areas of application.

TABLE 10.35

Z

Rare-earth elements and their usefulness.

Symbol Name

Abundance (Keith et al., n.d.; Hammond, 2009) (ppma)

Selected applications

21 Sc

Scandium

Light aluminum-scandium alloys for aerospace components, additive in metal-halide lamps and mercury-vapor lamps, (Hammond, 2009) radioactive tracing agent in oil refineries

22

39 Y

Yttrium

Yttrium aluminum garnet (YAG) laser, yttrium 33 vanadate (YVO4) as host for europium in television red phosphor, YBCO high-temperature superconductors, yttria-stabilized zirconia (YSZ) (used in tooth crowns; as refractory material—in metal alloys used in jet engines, and coatings of engines and industrial gas turbines; electroceramics—for measuring oxygen and pH of hot water solutions, that is, in fuel cells; ceramic electrolyte—used in solid (Continued)

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TABLE 10.35 (Continued)

Z

Symbol Name

Abundance (Keith et al., n.d.; Hammond, 2009) (ppma)

Selected applications oxide fuel cell; jewelry—for its hardness and optical properties; do-it-yourself high temperature ceramics and cements based on water), yttrium iron garnet (YIG) microwave filters, (Hammond, 2009) energy-efficient light bulbs (part of triphosphor white phosphor coating in fluorescent tubes, CFLs and CCFLs, and yellow phosphor coating in white LEDs), spark plugs, gas mantles, additive to steel, aluminum and magnesium alloys, cancer treatments, camera and refractive telescope lenses (due to high refractive index and very low thermal expansion), battery cathodes (LYP)

57 La

Lanthanum

High refractive index and alkali-resistant glass, flint, hydrogen storage, battery-electrodes, camera and refractive telescope lenses, fluid catalytic cracking catalyst for oil refineries

39

58 Ce

Cerium

Chemical oxidizing agent, polishing powder, yellow colors in glass and ceramics, catalyst for self-cleaning ovens, fluid catalytic cracking catalyst for oil refineries, ferrocerium flints for lighters, robust intrinsically hydrophobic coatings for turbine blades (Fronzi, 2019).

66.5

59 Pr

Praseodymium Rare-earth magnets, lasers, core material for carbon arc lighting, colorant in glasses and enamels, additive in didymium glass used in welding goggles (Hammond, 2009), ferrocerium fire steel (flint) products, single mode fiber optical amplifiers (as a dopant of fluoride glass)

9.2

60 Nd

Neodymium

Rare-earth magnets, lasers, violet colors in glass and ceramics, didymium glass, ceramic capacitors, electric motors of electric automobiles

41.5

61 Pm

Promethium

Nuclear batteries, luminous paint

1 3 10215 [12]b

62 Sm

Samarium

Rare-earth magnets, lasers, neutron capture, masers, control rods of nuclear reactors

7.05

63 Eu

Europium

Red and blue phosphors, lasers, mercury-vapor lamps, 2 fluorescent lamps, NMR relaxation agent

64 Gd

Gadolinium

High refractive index glass or garnets, lasers, X-ray 6.2 tubes, Bubble (computer) memories, neutron capture, MRI contrast agent, NMR relaxation agent, steel and chromium alloys additive, magnetic refrigeration (using significant magnetocaloric effect), positron emission tomography scintillator detectors, substrate for magneto-optical films, high-performance hightemperature superconductors, ceramic electrolyte used (Continued)

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TABLE 10.35

Z

(Continued)

Symbol Name

Abundance (Keith et al., n.d.; Hammond, 2009) (ppma)

Selected applications in solid oxide fuel cells, oxygen detectors, possibly in catalytic conversion of automobile fumes.

65 Tb

Terbium

Additive in Neodymium based magnets, green phosphors, lasers, fluorescent lamps (as part of the white triband phosphor coating), magnetostrictive alloys such as terfenol-D, naval sonar systems, stabilizer of fuel cells

1.2

66 Dy

Dysprosium

Additive in Neodymium based magnets, lasers, magnetostrictive alloys such as terfenol-D, hard disk drives

5.2

67 Ho

Holmium

Lasers, wavelength calibration standards for optical spectrophotometers, magnets

1.3

68 Er

Erbium

Infrared lasers, vanadium steel, fiber-optic technology

3.5

69 Tm

Thulium

Portable X-ray machines, metal-halide lamps, lasers

0.52

70 Yb

Ytterbium

Infrared lasers, chemical reducing agents, decoy flares, 3.2 stainless steel, stress gauges, nuclear medicine, monitoring earthquakes

71 Lu

Lutetium

Positron emission tomography—PET scan detectors, 0.8 high-refractive-index glass, lutetium tantalate hosts for phosphors, catalyst used in refineries, LED light bulb

Parts per million in earth’s crust, for example, Pb 5 13 ppm. No stable isotopes occurring in nature.

a

b

A series of corrosion tests were performed to study the effectiveness of various natural additives. Visual observations, SEM analyses, and computer image analyzer techniques were used to study the effects of SRB on the different coupon surfaces. It was observed that the presence of coatings inhibited both the biofilm growth and biocorrosion effects. The SRB Desulfovibrio desulfuricans culture medium was prepared with the following composition: KH2PO4 (0.5 g/L), NH4Cl (1.0 g/L), Na2SO4 (1.0 g/L), CaCl2
2H2O (0.1 g/L), MgSO4.7H2O (2.0 g/L), sodium lactate (3.5 g/L), yeast extract (1.0 g/L), cysteine solution (1.0 mL/l), and ferrous ammonium sulfate (5.0 mL/l). Preparation of this media was performed by sequential addition of the compounds to deionized water. The pH of the culture was adjusted to 7.6, and the medium was sterilized at 130 C for 25 minutes. The medium was kept in an incubator at 33 C under anaerobic conditions (sealed containers). After 30 hours of inoculation, the population of SRB was counted using the plate count method and was found to be 6106 cells/mL. The oil-based coating was used to protect the mild steel surfaces from MIC effects. The oil-based coatings include materials that are based entirely on oil, such as linseed oilbased products, alkyds, alkyd enamels, oil-based varnishes, and similar materials. One of the principal characteristics of these types of coatings is that they are generally applied in

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TABLE 10.36 List of microbially induced corrosion studies carried out with various inhibitors. Metal

Medium

Inhibitor

References

Carbon steel

Hypersaline

Neem extract

El Mouaden et al. (2018)

Copper

Synthetic seawater

Chitosan polymer

Deng et al. (2020)

Aluminum

Phosphoric acid

Cassava starch

Umoren et al. (2009)

Aluminum

HCl

Exudate gum

Anaee et al. (2019)

Carbon steel

Phosphoric acid

Etoricoxib (drug)

Singh et al. (2020)

Copper and zinc

Artificial seawater

Tobacco

Ituen et al. (2020)

X80 steel

HCl

Allium cepa extract

Anadebe et al. (2020)

Moringa leaf

Yassir et al. (2018)

API 5LX

Carbon steel acid and alkaline 304L stainless steel

Medium based on artificial seawater consisting of Pseudomonas aeruginosa

Cistus ladanifer leaf

Agwa et al. (2017)

Steel

Winogradsky medium

Aloe vera extract

Narenkumar et al. (2017)

Mild steel

Cooling water

Ginger extract

Zadeh et al. (2020)

st37 steel

Cooling tower water

Myrtus communis extract Kokilaramani et al. (2020)

Mild steel

1.5% NaCl

Artemisia pallens

Agarry et al. (2019)

Moringa oleifera leaves, and Carica papaya peels

Nwigwe et al. (2019)

Carica papaya

Rasheed et al. (2020)

Chitosan-based nanocomposite

AlAbbas et al. (2013)

Mild steel crude oil
water environment Mild steel

Marine environment

Carbon steel sulfatereducing bacteria media

thin films. Another characteristic is their ability to spread over most solid surfaces. On the other hand, one of the oil coating disadvantages is that they are not highly corrosion resistant. This is due to the relatively high moisture vapor transfer rate and the transfer of ions through the coating. In that study, an alkyd coating was used because it has the broadest usage. Alkyds also can be modified to improve their properties, mainly their corrosion resistance. The alkyd coating was applied on 800-grid hand-polished mild steel surfaces using a brush. The average coating thickness was measured and found to be in the range of 4
5 mm. Natural products were added to both the media and the alkyd coating to study their effects on the modified coating protective properties compared to the basic

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FIGURE 10.51

H

Stereochemical structure and configuration of triacylglycerols.

H C OOCR’ R′′COO C

H

H C OOCR′′′ H

FIGURE 10.52

SEM photomicrograph

of the SRB.

ones. Nearly all the natural oils of both the animal origin, Manhaden fish oil, and the plant origin, olive oil, consist almost exclusively of the simple lipid class—triacylglycerols with the stereochemical configuration shown in Fig. 10.51. The different metal coupons were then immersed in the SRB medium and kept in sealed containers for 3 months. The studied coupons were uncoated mild steel, mild steel coated with alkyd, mild steel coated with alkyd mixed with Manhaden fish oil, and mild steel coated with alkyd mixed with olive oil. After the 3 months of incubation period, the samples were investigated using different microscopic and analytical techniques. It was found that the SRB, as shown in Fig. 10.52, grew at different rates in the medium and on the different studied mild steel surfaces. This growth led to the formation of continuous and discrete biofilms and bacterial colonies attached to the coupon surfaces, as shown in Fig. 10.52. Within each biofilm, the local physical and chemical conditions created an environment that helped in the microorganism’s attack. These biofilms caused profound MIC on the surfaces on which they grew at different rates. SEMs of mild steel surfaces showed heavy microbial colonization after exposure to the SRB culture for 3 months. Fig. 10.53 shows an SEM of an uncoated mild steel coupon. Bacteria colonies and biofilm matrices were observed to be attached to the surface and between the layers of the

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FIGURE 10.53 SEM photomicrograph of the bacterial colonies attached to the coupon surfaces.

FIGURE 10.54 SEM photomicrograph of uncoated mild steel shows the corrosion products and the SRB attack on the surface.

heavy and dense corrosion products. Small holes under the corrosion product deposits were observed, and this can be attributed to both the SRB and chloride attacks. Most MIC, however, manifests as localized corrosion because most of the organisms do not form in a continuous film on the metal surface. Microscopic organisms tend to settle on metal surfaces in the form of discrete colonies or at least in a spotty manner rather than in continuous films, and this explains the localized (intergranular or pitting) corrosion on the metal coupons shown in Fig. 10.54. Fig. 10.55 shows an SEM of a mild steel coupon coated with alkyd without any additives. Bacterial colonies and biofilm matrixes can be seen attached to the coated surface. Breaching of the coating was detected on the surface, which led to severe localized

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FIGURE 10.55

SEM photomicrograph shows the localized attack (pitting) on an uncoated mild steel coupon surface.

FIGURE 10.56

SEM photomicrograph shows heavy bacteria colonization and biofilms attached to the surface of a mild steel coupon coated with alkyd.

corrosion (Fig. 10.56). Biodegradation of the coating was also detected as holes with bacteria in and around the pits, as can be seen in Fig. 10.57. Black ferrous sulfide deposits were also detected underneath the breaches in the coating layer. These effects were highly pronounced at the corners, edges, and around the suspension hole. Microbial Corrosion Prevention Using Natural Additives 1015 Fig. 10.58 shows an SEM of a mild steel coupon coated with alkyd mixed with olive oil. No biofilm was detected on the surface, but a few spots were observed at different locations on the surface. Blistering with and without rupturing of the coating was observed on the coated surface, as shown in Fig. 10.10, which is an indication of some microbial processes occurring beneath the coating.

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FIGURE 10.57 SEM photomicrograph of an alkyd-coated mild steel surface shows breaching, cracks, and failure of the coating.

FIGURE 10.58 SEM photomicrograph of a mild steel surface coated with alkyd shows the bacteria in and around the holidays and cracks in the surface.

It is worth mentioning here that the SRB existing in the slim layer (biofilm) converts sulfates in the sample into H2S. The hydrogen sulfide and carbon dioxide (CO2) react with water to produce a mild acidic condition that affects the metal surface. This process lowers the pH of the substrate surface to levels favorable for the growth of bacteria, which in the end creates a very acidic environment, thereby encouraging rapid corrosion. Fig. 10.59 shows an SEM of a mild steel coupon coated with an alkyd coating mixed with Manhaden fish oil. Few bacterial colonies and a very thin biofilm can be observed on the surface. No breaches, blistering, or deterioration were detected on the surface. The coated surface was found to be well protected. The black ferrous sulfide detected on some of the tested coupons confirmed the activity of SRB on the surfaces, and, as a result, a MIC attack The presence of SRB reduced sulfate to sulfide, which reacted with iron and produced the black ferrous sulfide (Figs. 10.60 and 10.61). Bacteria and biofilms were heavily attached to the uncoated and coated surfaces without natural additives as discrete colonies rather than continuous films. This explains the fast propagation rate of localized (intergranular or pitting) corrosion on those surfaces. The MIC attack appeared to proceed at a lower rate on the surfaces coated with alkyd mixed with the natural additives; there was a marked inhibition of bacterial adhesion on

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FIGURE 10.59

SEM photomicrograph shows some pinholes, spots, and localized attacks on the surface of a mild steel coupon coated with alkyd mixed with olive oil.

FIGURE 10.60

SEM photomicrograph shows blistering on the surface of a mild steel coupon coated with alkyd mixed with olive oil.

FIGURE 10.61

SEM photomicrograph shows the surface of a well-protected mild steel coupon coated with alkyd mixed with fish oil.

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these surfaces. It is believed that some of the additives increased the corrosion resistance properties of the modified alkyd. Mixing natural products, mainly fish oils with oil-based coatings like alkyd, showed a positive result toward inhibiting both the biofilm formation and the MIC effects on mild steel surfaces.

10.7 Modeling of microbially influenced corrosion The aim of this work is to develop a model capable of estimating the substrate concentration profiles in a biofilm containing industrial systems. The model derivation extended previous modeling work by including diffusional transport and a generalized bulk reaction mechanism, and by solving the resulting transport equation for unsteady flow patterns. The model is based on the principle of mass transport and can simulate a species disappearance mechanism under different flow conditions. The model accounts for the axial convection and radial diffusion in a pipe under different flow regimes. The transport of a given species in a liquid can be described quantitatively by the spatial and temporal evolution of its concentration; in other words, a differential equation for the concentration C(x, y, z, t). The differential equation must account for the reactions (sources or sinks of the species). The principle of conservation of mass requires that the chemical flux F 5 (Fx, Fy, Fz) and the concentration C satisfy the following mass balance equation (Perry and Green, 1997):  2

@Fy @Fx @Fz @C 1 1 1R2S5 @x @y @z @t

(10.13)

The term inside the brackets on the left-hand side of Eq. (10.13) represents the chemical influx minus efflux. The right-hand side of Eq. (10.13) represents the temporal change of solute in the bulk fluid. R and S represent the source and sink terms, respectively. In this investigation, a two-dimensional modeling was considered, and due to the nature of the systems involved a cylindrical coordinate system was chosen. Therefore, the mass balance equation shown in Eq. (10.1) can be rewritten in the following form:  2

@Fx 1 @ðrFr Þ @C 1 1R2S5 @x r @r @t

ð 2Þ

(10.14)

For a two-dimensional cylindrical transport, the axial (Fx) and radial (Fr) solute flux can be derived solely from advection and dispersion. For that, Fx and Fr can be described as: F x 5 ux C 2 D x

@C @x

ð2aÞ

(10.14a)

Fr 5 ur C 2 Dr

@C @r

ð2bÞ

(10.14b)

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where u x and u r are the velocity components in the x and r directions. In this investigation, the radial velocity was neglected due to the assumption of symmetry. Therefore Eq. (10.14) can be rewritten as (Bird et al., 2001):    @ @C 1@ @C @C ux C 2 Dx 2 2rDr 1R2S5 ð3Þ (10.15) 2 @x @x r @r @r @t Eq. (10.15) represents a very general differential equation that can be applied in different applications, like a fluid flow in cylindrical devices such as pipes. In this investigation, the differential equation shown by Eq. (10.3) will be used to study the concentration profiles of a given substrate in a pipeline system. The solution of the convective-diffusive mass balance equation given depends on the system under investigation. In other words, the solution of Eq. (10.15) has to be subjected to a prescribed boundary and initial conditions, which are characteristics of each system. The system in our investigation is a pipeline containing biofilm at its inner surface, and a fluid-containing substrate flowing through it. The substrate concentrations model in cylindrical coordinates can be derived using the principle of mass conservation in a pipe. A mass balance over a fluid element in a single pipe was developed, accounting for the transport by convection and radial diffusion, and for the substrate consumption in the bulk fluid according to a first-order reaction term. For unsteady transport of a substrate in a pipe of length L* and a radius r 0*, the material conservation equation accounting for the aforementioned mechanisms can be written as:     @ UTf ðrTÞCT @CT @ @CT 1 @ @CT 1 52 D 1 rTD 1 RT ð4Þ (10.16) @xT @tT @xT @xT rT @rT @rT The term on the left-hand side of Eq. (10.16) accounts for changes in the substrate concentration with time. The first term on the right-hand side of Eq. (10.16) describes advective transport, whereas the second term represents diffusion in both the axial and radial directions, respectively. The third and last term on the right-hand side of Eq. (10.16), R*, can be either a general sink term or the sulfate consumption rate by bacteria at any point in the system. The f(r*) is a term that accounts for the flow profile present in the pipe. U* is the average or hydraulic velocity of the liquid flowing in the pipe under consideration. D is the diffusion coefficient of the substrate in the bulk flow. The system can be described using cylindrical coordinates and having the center of the pipe at the inlet as the origin, as shown in Fig. 10.62. The boundary and initial conditions for the model shown in Fig. 10.62 are: xT 5 0;

CT 5 C0

ð5aÞ

(10.17a)

FIGURE 10.62 The pipeline system under modeling.

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xT 5 L;

@2 CT 50 @x2

ð5bÞ

(10.17b)

rT 5 0;

@CT 50 @rT

ð5cÞ

(10.17c)

rT 5 r0 ;

D

@CT 5 2 RB @rT

ð5dÞ

(10.17d)

where R* B is the substrate consumption rate on the biofilm surface, and inside the biofilm: tT 5 0; CTðxT;rTÞ 5 CTinitial ðxT;rTÞ 5 0 ð5eÞ The function f(rT) describes the radial velocity distribution in the pipe depending on the flow range. For a laminar flow (Re , 2300) in a pipe, f(rT) has a parabolic shape which is described by the Poiseuille formulation: For turbulent flow, a uniform velocity profile can be  2 ! rT ð6Þ (10.18) f ðrTÞ 5 2 1 2 T r0 Assumed: f ðrTÞ 5 1 ð7Þ. For transport and reaction under stagnant conditions: f ðrTÞ 5 0 ð8Þ. As was mentioned previously, D is the diffusion coefficient of the substrate in the liquid under investigation. In the laminar flow range, D is equal to the molecular diffusion coefficient Dm. For the turbulent case, D represents the turbulent diffusivity which is the sum of the molecular diffusion coefficient (Dm) and the eddy diffusivity (E), which is dependent on the distance from the wall. Based on Reichardt’s law for a pipe, E can be rT rT 2 T pαffiffiffi ð1 1 rT0 Þ  ð1 1 2ðrT0 Þ Þ calculated as follows: ε 5 0:4UT r0 2 rT 8 where α is given as follows: 6





1:32547 α5 h  i2 5:74 ln 3:7ðe2rTÞ 1 ðRe 0:9 Þ

ð10Þ

(10.19)

Concerning the term RT in Eq. (10.19), which is the rate of substrate consumption in the pipe, it can be calculated using the Monod equation. This is because microbial growth is usually represented with Monod kinetics and the rate of substrate utilization is assumed proportional to the rate of microbial growth (Grady et al., 1999). From that, the substrate utilization rate can be calculated as: RT 5

qxc CT Km 1 CT

ð11Þ

where RT

substrate consumption rate, mol/m3-h

q

maximum substrate utilization rate, mol/g-h

Xc

bacteria concentration, g/m3

Km

Monod half velocity coefficient, mol/m3

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The Monod equation can also be written as: RT 5 RT 5 1 1k1kCT where k1 and k2 are con2 CT stants with the units of s21 and L/mg, respectively. The local average concentration (based on cross-sectional area) was calculated from the detailed substrate concentration profile C(X, r, t) by the following integral: where X is the nondimensional x position along the pipe. Ð r0 Cðx;r;tÞ r dr ð12Þ (10.21) CðX; tÞ 5 0 Ð r0 0 r dr



 

The resulting governing equation with its initial and boundary conditions that describe the substrate concentration in the pipe system was solved numerically under different conditions. In order to solve these model equations numerically for different combinations of parameters, the governing equation with its initial and boundary conditions was first transformed to the nondimensional form then discretized by an alternating difference implicit (ADI) scheme. The ADI scheme is superior when compared to many other numerical approaches, such as Barakat Clark and Crank-Nicholson methods, for several reasons (Carnahan et al., 1969; Ozdemir and Ger, 1999). First, the ADI scheme produces a stable solution regardless of the choice of the time step and the discretization grid size, and for that, the model results will always be reasonable. Second, the ADI method creates an unsteady solution, using the finite differences in the spatial directions x and r to find a solution at the next time level, while the Crank-Nicholson scheme uses finite differences in one spatial dimension to obtain the steady-state solution throughout the grid. Furthermore, the Crank-Nicholson scheme is not capable of accounting for the axial spreading of species by diffusion. The ADI scheme which is being used in this study to find the solution of the general model of substrate transport and consumption in a pipe belongs to a class of numerical methods that are unconditionally stable and are second-order accurate with a total error on the order of Ob(Δ t)2, (Δ x)2, (Δ r)2c. Regardless of the choice of the step sizes in both the time and the spatial dimensions, the method produces stable results. In applying the ADI scheme, finite difference techniques are used to advance the solution in time at each location in the grid. In the ADI scheme, each time step is split into two half steps. During the first time step, the solution at the time level (n11/2) is created by using finite differences at the new time level (n11/2) for all partial derivatives in r, and finite differences at the old time level n for all partial differences in x. After that, and following the same procedure, the solution at the end of the time step (n11) will be considered with respect to x. It should be noted that Eq. (10.12) was converted to a programmable form by employing the discrete values of C in a computational grid as follows:  Pj max  C i; j; t rj Δrj j51 ð13Þ (10.22) Cðx;tÞ 5 Pj max rj Δrj j51



 

In this investigation, the model was solved for water-containing substrate (glucose) and bacteria flowing in a pipe containing biofilm. The inlet substrate concentration (Co) was taken to be 100 mg/L. The pipe length (L) and radius (r) were taken to be 10 m and 1 cm, respectively. The diffusion coefficient of the substrate in water was taken to be 6 3 1026 cm2/s (Baillod and Boyle, 1970).

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The Monod equation was used to calculate the substrate consumption rate in the bulk flow. The kinetic parameters in Monod equations k1 and k2 were taken to be 0.06 s21 and 0.0083 l/mg (Kirkpatrick et al., 1980). In the model solution, it was assumed that the total amount of substrate that reaches the biofilm surface will be consumed. The model was then solved for different flow regimes with different Reynolds numbers. As was mentioned previously, the main objective of solving our model is to estimate the substrate concentration profiles on the biofilm surface and at any other point in the system under investigation (pipeline). Fig. 10.2 shows the substrate concentration profiles’ development along the pipeline under laminar flow conditions. It is clear from Fig. 10.63 that the model was successful in calculating the transient substrate concentration values at any point in the pipe (at each point of the numerical grid). The steady-state conditions were achieved after 1 hour. As shown in Fig. 10.63, the concentration values were calculated at the biofilm surface, and as area average values. The importance of calculating the substrate concentration values at the biofilm surface is that these values determine the rate of consumption of the substrate on the biofilm surface, which in turn affects the associated processes resulting from the presence and growth of those biofilms, like degradation and corrosion. It can also be observed from Fig. 10.63 that the curvature of the area average concentration profile curve is less steep than the curvature of the concentration profile curve on the biofilm surface. This is due to the fact that as we move from the biofilm surface, the rate of substrate consumption decreases. Fig. 10.64 shows the steady-state concentration profiles at the biofilm surface and along the center of the pipe under laminar flow conditions. The area average concentration profiles are also shown in Fig. 10.64. It is clear that the area average substrate concentration values are closer to the substrate concentration values in the pipe center line than the substrate concentration values on the biofilm surface. This is because the localized

1 Area average Concentration

C (Dimensionless)

0.8

1 hour

0.6

6 1 hour

4 Minutes

6

0.4 4

Substrate concentration profiles on the biofilm Surface

2 Minutes

0.2

0 0

0.2

0.4

0.6

0.8

1

X (Dimensionless)

FIGURE 10.63 Substrate concentration profiles development along the pipeline under laminar flow conditions (Re 5 1000).

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1 C(Center) C(Biofilm) C(Area Average)

C (Dimensionless)

0.8

0.6

0.4

0.2

0 0

0.2

0.4

0.6

0.8

1

X (Dimensionless)

FIGURE 10.64

Steady-state substrate concentration profiles at the biofilm surface and along the center of the pipe, as well as the area average concentration, under laminar flow conditions (Re 5 1000).

concentration profile values used in the calculation of the area average concentrations [refer to Eq. (10.12)] were of a parabola shape, as will be explained in the next paragraph. It can also be observed from Fig. 10.64 that the curvature of the concentration profile curves is least in the center and highest on the biofilm surface. This is because the center line represents the farthest point from the biofilm and, therefore, it is the least affected by the biofilm consumption of the substrate. It can be clearly seen from Fig. 10.64 that the rate of change in the substrate concentration is decreasing along the pipe length. Fig. 10.65 shows the steady-state concentration profiles at the biofilm surface and along the center of the pipe under turbulent flow conditions. The area average concentration profiles are also shown in Fig. 10.65. As was the case for the laminar flow, it is clear that the area average substrate concentration values are closer to the substrate concentration values in the pipe center line than the substrate concentration values on the biofilm surface, for the same reason given previously. At Re 5 5000, which is the case shown in Fig. 10.65, the turbulent eddies were very high, to the point that they contributed to more than 95% of the diffusion parameter at the center line of the pipe. This fact, along with the constant velocity profile (Eq. (10.7)), has made the concentration at the center line to be the dominant factor in the cross-sectional area average concentration. As a result, the relationship between the area average concentration and X was almost a straight line, as shown in Fig. 10.65. Fig. 10.66 shows the dependence of the substrate concentration profiles on the biofilm surface on Reynolds number values within the laminar flow range. It can be seen from Fig. 10.66 that the steady-state concentration values on the biofilm surface increase by increasing Reynolds number. This is due to the fact that increasing the flow velocity decreases the exposure time of substrate to the bacteria and the biofilm and, therefore, less amount of substrate will be consumed.

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1 C(Center) C(Biofilm) C(Area Average)

C (Dimensionless)

0.9

0.8

0.7

0.6 0.6

0.2

0.4

0.6

0.8

1

X (Dimensionless)

FIGURE 10.65

Steady-state substrate concentration profiles at the biofilm surface and along the center of the pipe, as well as the area average concentration profiles, under turbulent flow conditions (Re 5 5000).

1 C(Biofilm) Re= 1000 C(Biofilm) Re= 500

0.8 C (Dimensionless)

C(Biofilm) Re=100 C(Biofilm) Re=1500

0.6 C(Biofilm) Re= 2000

0.4

0.2

0 0

0.2

0.6 0.4 X (Dimensionless)

FIGURE 10.66

0.8

1

Effect of Reynolds number values in the laminar range on the steady-state substrate concentration profiles on the biofilm surface along the pipeline.

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The biofilm process rates may be controlled by mass transfer limitations in the bulk fluid phase. The substrate removal rate is dependent on the fluid velocity passing the biofilm. At low fluid velocities, a relatively thick mass transfer boundary layer can cause a fluid phase mass transfer resistance that decreases the substrate concentration at the fluid-biofilm interface, thereby decreasing the substrate removal rate. Two factors may result in low mass transfer rates from the bulk fluid to the biofilm: low fluid velocities and the transport of dilute liquid phase concentrations of the material (Characklis and Cooksey, 1983). Fig. 10.67 shows the substrate concentration profiles in the radial direction under laminar flow conditions. From Fig. 10.67, it can be observed that the concentration profiles in the radial direction have a parabolic shape (low at the surface of the pipe, max at the center). These results and observations are in agreement with our model and with the fact that the rate of substrate consumption at the biofilm surface is the highest compared to the consumption at any other point in the pipe. Fig. 10.68 shows the substrate concentration profiles in the radial direction under turbulent flow conditions. These concentration profiles are less steep than those under laminar flow conditions. This observation is the result of the velocity profiles that were used for the turbulent flow conditions. The effect of the eddy diffusivity is clear from the chaotic behavior of the concentration profiles in the radial direction. The turbulent flow behavior has resulted in a better mixing phenomenon (as compared to laminar flow) and, therefore, higher concentration values were obtained at the biofilm. Kirkpatrick et al. (1980) reported that for laminar flow, utilization of the substrate is diffusion limited in the fluid since radial mass transport is solely by molecular diffusion. They also found that in turbulent flow system, radial velocity fluctuations yielded a much higher effective diffusivity, which results in a well-mixed fluid phase.

1 X=0.5, 60 min

0.75

X=1.0, 60 min

r (Dimensionless)

0.5 0.25 0 0

0.2

0.4

0.6

0.8

1

-0.25 -0.5 -0.75 -1 C (Dimensionless)

FIGURE 10.67

Steady-state substrate concentration profiles in the radial direction at the middle and the end of the pipe under laminar flow conditions (Re 5 1000).

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10. Corrosion and its mitigation

FIGURE 10.68 Development of the substrate concentration profiles in the radial direction in the middle of the pipe under turbulent flow conditions (Re 5 5000).

FIGURE 10.69 Effect of Reynolds number on the outlet area average substrate concentration values under both laminar and turbulent flow conditions.

The effect of the Reynolds number on the outlet substrate concentration values under both laminar and turbulent flow conditions is shown in Fig. 10.69. It is clear that increasing Reynolds number (which in this investigation means increasing the velocity in the

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10.7 Modeling of microbially influenced corrosion

839

pipe) increases the value of the outlet substrate concentration. As was discussed previously, increasing the flow velocity decreases the residence time of the flowing fluid that contains the substrate and that, in turn, reduces the consumed amounts of the substrate. Fig. 10.69 also shows a sharp drop in the transition from laminar to turbulent flow. This sharp drop in the substrate concentration values is attributed to the eddy effects associated with turbulent flow. These eddies increase the rate of mixing and lead to higher mass transfer in the pipe and toward the biofilm surface which, in turn, results in higher substrate removal rates and, thus, lower outlet substrate concentrations.

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C H A P T E R

11 Conclusions Based on the discussion carried out in different chapters of this book, the following conclusions can be made.

11.1 Chapter 1: Introduction 1. True sustainability is about zero waste in the entire technology process. 2. A true paradigm involves zero-waste engineering in all aspects of petroleum resource development. 3. Historically, the knowledge and practices of true sustainability were available in every epoch, except for the current “plastic era,” in which artificial products are ubiquitous (Fig. 11.1). 4. During the plastic era, the technology development mode, with progressively more unsustainable technologies, as denoted by the Honey-Sugar-Saccharine-Aspartame (HSSA) allegorical transition. 5. The sustainability in the petroleum technology arises from the refining technologies that have employed progressively more toxic additives during the refining process. Though these additives are being used in small concentrations, their impact is vastly ignored in the sustainability analysis. FIGURE 11.1 The progression of knowledge in various epochs. Source: Redrawn from Islam et al., (2017).

Pipelines DOI: https://doi.org/10.1016/B978-0-12-820600-3.00001-9

841

© 2023 Elsevier Inc. All rights reserved.

842

11. Conclusions

6. Both mass and energy sources are culpable in rending the overall process unsustainable. 7. The chemicals used during pipeline transportation in order to facilitate flow or clear obstruction due to hydrate formation, corrosion, etc. are not artificial chemicals that are both unsustainable and toxic to the environment. 8. The solutions to the sustainability problem lie within introducing natural products and ultimately natural energy sources.

11.2 Chapter 2: Petroleum in the big picture 1. The petroleum era is a natural progression from other natural form of energy. 2. Today’s most accepted narrative of “green technology” is wrong headed and the demonization of fossil fuel is unscientific. 3. Petroleum resources are natural and would be wholly sustainable if sustainable systems are employed at each level of processing, transportation, and utilization. 4. Petroleum commodities are the most politicized among all resources in use today. Political events affect technological developments and strategic priorities. The demonization of petroleum resources or so-called carbon hysteria comes from a mindset, deeply rooted in Eurocentric bias (Fig. 11.2) and accounts for today’s economic extremism and technological disaster (Fig. 11.3). FIGURE 11.2 Both scientific and social theories have invoked phenomenal premises that have become increasingly illogical.

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11.2 Chapter 2: Petroleum in the big picture

843 FIGURE 11.3 Illogical premises have been either adopted without questioning its legitimacy or worse have been replaced with more illogical premises. In this process, there have been two different tracks. On the one side, we have the pro-morality scholars while on the other side, we have more “secular” scholars, both sides promoting the same model that was once touted by Thomas Aquinas.

PICTURE 11.1 The fuel for electric car. The biggest blunder of New science is to replace natural material and process with artificial alternatives, then call the artificial ones sustainable.

5. None of the strategic focus of the USA (and UN) in the post-US President Clinton era has been science based, with the exception of the 4 years of President Trump presidency. 6. Technologies related to so-called renewable energy are disastrous, both economically and environment wise (Picture 11.1).

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11. Conclusions

7. The Agenda-21 and the New World Order, as promoted by the United Nations, are entirely counterproductive and will most definitely lead to unprecedented energy crisis and disastrous inequity and economic extremism. 8. Data suggest that the energy policies executed by President Trump were closest to true sustainability. 9. Only natural resources such as fossil fuel and biomass are sustainable and have the potential of reaching true sustainability. 10. Each level of sustainability measure has introduced a lower level of true sustainability and lower global efficiency but higher profit margin for the developers. 11. For petroleum operations, it meant crude oil has been made progressively less sustainable by introducing refined.

11.3 Chapter 3: Fundamentals of processing 1. Modern era is the only known era, in which denaturing of natural materials is used as the first step of material process. This is valid for both crude oil and natural gas. As such, modern-day processing techniques are inherently unsustainable. 2. Modern refining and gas processing technologies are used to custom design a product to particular application, thus losing versality. The applications and involved machineries are also designed for the designated refined product. As a result, the whole engineering process is inefficient and user hostile. 3. Post-Newtonian New Science bases all calculations on the assumption of Newtonian mechanics, atomism, and their derivatives (e.g., quantum mechanics). This process introduces inherent bias and makes it impossible to investigate the environmental impact of a technology. 4. In order to evaluate true sustainability, the mathematical description should eliminate New Science biases and their false premises. Correct formulation forms the basis for both sustainable criteria and sustainable technologies. 5. The new formulation remediates the most consequential false premise of New Science, that is, mass and energy are describable discretely with no means of including interaction between them (i.e., Bose
Einstein condensate theory and Einstein light theory). 6. The correct formulation distinguishes between natural energy and artificial energy, which then creates a. protocol for developing sustainable energy development (Fig. 11.4). 7. Only natural processes can be beneficial (Fig. 11.5).

11.4 Chapter 4: Fundamentals of separation of oil and gas 1. The separation process is the closest to truly sustainable process. 2. The Haber process marked the beginning of plastic culture that would see replacement of natural processes with artificial ones, leading to the subsequent focus in synthesizing artificial materials.

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11.4 Chapter 4: Fundamentals of separation of oil and gas

845

FIGURE 11.4 Sunlight and artificial light cannot be conflated as one and must be distinguished.

FIGURE 11.5 Only natural processing can be beneficial and sustainable.

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11. Conclusions

3. Langmuir’s kinetic studies were useful surface chemistry tools. However, their application to first electrochemistry and then quantum chemistry has created a quagmire, leading to numerous contradictions. 4. A single governing equation that is valid in all scales is effective in describing surface phenomena while retaining mass conservation of all matter. 5. By keeping the source information of any matter, protocols for sustainability can be developed. 6. Currently used catalysts and performance agents, including surfactants, are either synthetic or artificially refined. 7. Zeolite and other natural materials offer a sustainable alternative to currently used catalysts. 8. The comprehensive mass
energy model can track the effect of artificial chemicals or energy source in any process.

11.5 Chapter 5: Transportation of oil and gas 1. Pipeline network is synonymous with oil and gas energy revolution. 2. Progress in pipeline technology is in lockstep with gas and oil processing technology. 3. The most important innovations in pipeline technologies involve materials and monitoring technology. 4. Heavy oil transportation offers challenge and creates hydrodynamic quagmire. Most existing solutions rely on adding chemicals or heat. These processes can be rendered sustainable if natural chemicals and heating processes are used to replace the currently used means. 5. Tremendous progress has been made in monitoring of pipelines. However, little progress has been made to fine-tune the governing equations that describe fluid and energy transport, particularly under predominantly non-Newtonian regime.

11.6 Chapter 6: Advances in pipeline designs 1. The surge in satellite technology created an opportunity for real-time monitoring. 2. The emergence of CO2 capture as a means of combating climate change issues has opened up opportunities for networking with pipelines. 3. Pipeline network design should include the role of CO2. 4. Sustainability of CO2 capture and storage hinges upon minimizing artificial chemicals and maximizing use of local resources, both in mass and energy. 5. Total sustainability can assure a closed loop in carbon cycle, thus assuring perpetual supply of fossil fuel. 6. Unlike what has become a “settled science” narrative, sustainability is not affected by the quality of original petroleum resource, they are all sustainable if the natural CO2 cycle is not broken (Fig. 11.6).

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11.8 Chapter 8: Fundamental considerations of oil and gas separation

FIGURE 11.6

The sustainability is in retaining natural traits of matter.

7. Under sustainable conditions, the economics becomes much better than conventional approaches, debunking the common myth that sustainable development is more pricey than conventional techniques. 8. Many monitoring technologies are emerging with increasingly higher level of accuracy, but data gap exists, for which more research must be conducted.

11.7 Chapter 7: Storage of petroleum fluids 1. Global oil inventory has suffered significantly after the post-COVID-19 crisis, accentuated by global instability as well as push for renewable energy. 2. Underground gas storage facilities are typically undervalued. 3. At present, abandoned oil/gas fields offer the most promising storage site for oil and gas. However, many of these sites can be refurbished for depleting further with sustainable enhanced oil/gas recovery schemes.

11.8 Chapter 8: Fundamental considerations of oil and gas separation 1. Many novel materials have been developed that enhance oil
water separation. These are, however, not sustainable.

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11. Conclusions

2. The key to sustainability is to use natural materials. Certain desert sands exhibit unique properties that are more effective in separating different phases than artificial materials. 3. Gas
oil separation can be greatly enhanced with jet motion, which increases the interfacial area by several orders of magnitude. This leads to the alteration of viscosity, interfacial tension, and others. 4. Natural materials exist that would enhance the oil/gas separation process. 5. Ideal gas laws are grossly inadequate to describe physical phenomena within a separation unit. 6. The underlying premises of Planck’s law, Bose
Einstein light theory, and other physical laws, describing mass to energy transition, are devoid of logic and explain why dogmatic assertions were needed in name of quantum mechanics. 7. If the above false premises are replaced with phenomenal premises, a new theory emerges that can explain the difference between natural light and artificial light.

11.9 Chapter 9: Gas hydrate and its mitigation 1. Natural gas processing is unlike oil refining as the purposes of these processes are radically different. 2. Gas hydrates are considered to be a major obstacle to gas flow and most technological advances target mitigation, rather than using gas hydrates as a source of energy. 3. Currently used solvents and additives, used for the prevention of natural gas, are either synthetic or processed through unsustainable means. 4. Sustainable processes that can mitigate hydrate formation are chemicals of natural origin, bacteriogenic, or direct solar energy.

11.10 Chapter 10: Corrosion and its mitigation 1. The origin of corrosion is in the metal processing technology that denatures metal. 2. Material processing in pre-Industrial era used to be different from today’s technology and used to be sustainable. 3. Vulnerability to environmental degradation has increased from cast iron to steel. 4. Stainless steel although prevents corrosion in the short term, long-term vulnerability and environmental damage are monumental. 5. Significant progress has been made in introducing natural materials for corrosion protection, but only few of these materials are entirely sustainable. 6. Organic processing of metal is scientifically sustainable. However, no application has been reported in modern era, thus keeping this research topic wide open.

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Index Note: Page numbers followed by “f” and “t” refer to figures and tables, respectively.

A AA. See Antiagglomerants (AA) Absorption, 201 Abu Dhabi National Oil Company (ADNOC), 24
25 Abundant micropipes, 580
581 Accelerometers, 460f, 463
464 Accuracy, 492
493 Acetic acid, 703 Acid, 671 acid-function catalysts, 224
226 gases, 644 pickling process, 806
807 Acoustic correlation techniques, 453 Acoustic emission sensors (AE sensors), 450
458, 475t, 491
492 AF versus RA, comparison between conditions NL and Lk-3, 452f fault detection methods, 459f percentage variation of AE parameters, 452f schematics and characteristics of test bed with unburied pipe, 451f Acoustic reflectometry, 458, 461 blockage in pipe, 462f matched filtering analysis of 800 Hz waves, 462f reflections of 800 Hz f0180 waves, 461f Acoustic sensors, 445 Active methods, for leak detection, 453 Active thermography, 470
471 ACTL. See Alberta Carbon Trunk Line (ACTL) Acute fluoride toxicity, 242 AD. See Alzheimer disease (AD) Adaptability, 492
493 Adaptive noise reduction method based on variational mode decomposition (ANR-VMD), 482 Additives, 720 cadmium, 231
235 drag reducing additives, 382
387 functions, 229
239 lead, 236
239 platinum, 229
231 toxic, 721t Adenosine triphosphate (ATP), 286 ADI. See Alternating difference implicit (ADI)

Adiabatic processes, 123
124 Adjustable phase transition theory, 154 ADNOC. See Abu Dhabi National Oil Company (ADNOC) Adsorption, 203, 595 of hydrogenocarbonate, 237
239 process of physisorption, 200 thermodynamics, 595 Adsorption
desorption equilibria, 194
195 Aerosols, 592
597 droplet size distributions after atomization of pure water, 593f spray combustion process, 592f viscosity, droplet size, and atomization, 596f Aerosols, 592
597 droplet size distributions after atomization of pure water, 593f spray combustion process, 592f After lightening (AL), 293
294 Agar media, 687 Agenda-21, 50
51, 844 Agricultural products, 241
242 AI. See Artificial intelligence (AI) Air evaporative liquid nitrogen jet in, 588f in scientific characterization, 116
121 Airbus intelligence, 403 Aircraft fuel systems, 793 Airplanes, 446 Alberta Carbon Trunk Line (ACTL), 405
406, 410 Alcohols, 647 Alfalfa, 312 Aligned nanotube membranes, 219
220 Aliphatic alcohol, 674 Alkaline resistance, 573 Alkaline solutions, 748 Alkyl-substituted benzenes, 224
226 Alkylated aromatics, 691 Alkylation, 223t Alternating difference implicit (ADI), 833 Alumina, 224
226 nanoparticles, 358
360 Aluminium, 797

881

882 Aluminium
magnesium alloy, 797
798 Aluminum (Al), 191, 240
241, 241f, 750, 752 alloys, 759, 792 dome roof, 514
515 Aluminum oxides, 200, 338 Alveolar macrophage, 729 Alzheimer disease (AD), 632 Amalgamation process, 792
793 American Petroleum Institute (API), 3, 320, 492
493, 511 separators, 558
559, 558f American Society of Mechanical Engineering (ASME), 335, 450, 515 Amide, 200 Amines, 183, 674, 676 pathways of, 181
183 Amino acids, 312 Ammonia (NH3), 111, 156, 226, 515
516, 675, 681, 707
708 synthesis catalysts, 200 synthesis plants, 200 Ammonium (NH4), 312 Ammonium chloride, 702 Ammonium hydroxide, 111 Amorphous silica
alumina, 261
262 Amplified effect, 573 Amplitude of measured pressure signal, 453 Amsterdam-Rotterdam-Antwerp (ARA), 23 Amyloid peptides, 240
241 Anaerobic iron corrosion, 795 Analcime, 249 Angiosarcoma, 728
729 Angular moments, 208 Anionic species, 783 ANN. See Artificial neural network (ANN) Anodic method, 749
750 Anodic protection system, 749
750 ANR-VMD. See Adaptive noise reduction method based on variational mode decomposition (ANR-VMD) Anthracene, 226 Anti-Stokes components, 465
466 Antiagglomerants (AA), 667
670 ANWR. See Arctic National Wildlife Refuge (ANWR) AO. See Atomic orbital (AO) API. See American Petroleum Institute (API) Applet signal filtering algorithm, 496 Aquaphones, 453, 455
456 Aqueous ammonia, 681 ARA. See Amsterdam-Rotterdam-Antwerp (ARA) Arctic National Wildlife Refuge (ANWR), 349 Area coverage, 491
492 Area ratio, 460
461

Index

Aromatics (A), 351 hydrocarbons, 224
226 Arrhenius constant, 765
766 Arrhenius equation, 755 Arsenic, 112
114 Artificial energy, 844 sources, 714 Artificial intelligence (AI), 354 artificial intelligence-based observers, 486
487 Artificial neural network (ANN), 456 Artificial process, 217 ARX. See Autoregressive with exogenous input (ARX) ASME. See American Society of Mechanical Engineering (ASME) Asphalt enamel coating, 771 Asphaltenes (A), 351
352 Asphaltenic crude oil, 384 Astronomers, 616 Astronomical unit (AU), 267
268, 296
297 Atmosphere, 673
674 Atmospheric corrosion, 754
761 dry corrosion, 755
759 reaction of various metals, 756t wet corrosion, 759
761 corrosion potential for various metals, 758t Atmospheric distillation, 150
174, 192 conventional phase diagram, 151f improving distillation, 151
164, 162f, 163f 4-component basic configuration, 152f 6-component basic configuration, 152f Brugma configuration, 152f derived HMP configuration, 152f DWC of Brugma configuration, 152f enumeration of HMP configurations, 153t heat and mass integrated configuration, 152f manipulated variables of optimization, 159f simple adiabatic column with total condenser, 161f US-ERD process, 158f optimization, 164
174 identification of “d” submixtures in matrix, 166f matrix for five-component feed mixture, 166f matrix for three-component feed mixture, 171f steps, 165
173 Atmospheric tides, 301 Atomic orbital (AO), 208 Atomic oxygen, 282 Atomic theory, 208
209 Atomism, 620, 844 Atomization process, 592 Atoms, photoemission from, 609
610 ATP. See Adenosine triphosphate (ATP) AU. See Astronomical unit (AU) Auger effect, 609

Index

Automated detection, 447 Automotive industry, 252
253 Autonomous underwater vehicles (AUVs), 449
450, 476 Autoregressive with exogenous input (ARX), 484
485 AUVs. See Autonomous underwater vehicles (AUVs) Auxiliary emissions, 180 Avalanche model, 206 Avalanche theory, 126
129 Aviation gasoline, 395 Avogadro’s law, 600
601

B Backpropagation (BP), 457 Bacteria, 309, 682, 689, 820, 828 growth and survival requirements, 684 species, 743 Bacteria counts, 687
689 computer image analyzer, 688f cover slide and circle, 689f Bactericides, 227 Balneophototherapy, 632 Band gap concept, 209
210 Barium, 616 Barophiles, reaction mechanisms of, 683 Base gas, 526 Basic solids, 256
257 Battery electric vehicles worldwide, 57f Bayesian estimators, 486
487 BCM. See Billion cubic meters (BCM) Beans, 312 BEC. See Bose
Einstein condensation (BEC) Before lightening (BL), 293
294 BEM. See Boundary element method (BEM) Benfield process, 201
202 Bentonite, 733
736 Benzene, 226 Beta-decay process, 628 BFG. See Blast furnace gas (BFG) BHT. See Butylated hydroxytoluene (BHT) Billion cubic meters (BCM), 328
329, 550, 652 Bilton Welding and Manufacturing, 410 Binding energy, 609 Bioactive compounds, 814 Biochemical microsensors, 795, 811 Biocorrosion, 810 Biodegradation, 826
827 Biofilm, 743 matrixes, 826
827 process, 837 Bioinspired membranes, 219
220 Biological methods, 448 Biological treatments, 561 Biomass (BM), 74, 130, 416

883

Biomedical industries, 245
246 Biphenyls, 691 Bitumen coatings, 718 Black body, 136 Black ferrous sulfide, 827
828 Black shales, 307
309 Black-box approach, 122 BlackBridge, 403 Blast furnace gas (BFG), 730
736 chemical additives and function in process, 734t pusher furnace, 732f Blockage, 458 detection, 461
462 length, 461 Blood coagulation glycoproteins, 240
241 Bloomery process, 730 BLT. See Bright light therapy (BLT) Bolt looseness, 477 Bolted connections, 477 Bolted joint model, 477
480 Boltzmann constant, 610 Bonding pair, 204 Bose
Einstein condensation (BEC), 133
134 Bose
Einstein theory, 600, 604 of condensate, 138 BOSS Environmental, 410 Boudouard reaction, 156 Boundary element method (BEM), 484 Boyle’s law, depiction of, 601f BP. See Backpropagation (BP) Bremsstrahlung γ-rays, 292 Bright light therapy (BLT), 631 Brillouin scattering, 464
467 British Thermal Unit (BTU), 340 Brooge Energy, 24
25 BTU. See British Thermal Unit (BTU) Bulk materials, 191 1,3-butadiene, 226 Butane, 11, 364, 515
516, 644, 651, 702 Butylated hydroxytoluene (BHT), 111

C Cadmium, 114, 231
235, 241
242 cadmium-coated steel, 750 coordination environment of Cd in complex 1, 233f detoxification, 231
232 fume fever, 241
242 Cadmium telluride, 83
84 CAF. See Core annular flow (CAF) CAFE. See Corporate Average Fuel Economy (CAFE) Cage-shaped crystal, 657 CalB. See Lipase B from yeast Candida antarctica (CalB) Calcination, 106
107

884

Index

Calcium, 361 Calcium chloride, 361
362 Calcium oxide, 730 Calvin
Benson photosynthetic cycle, 269 Canada Pension Plan Investment Board (CPPIB), 409 Canadian Energy Regulator (CER), 319 Canadian Environmental Assessment Agency (CEAA), 405 Canola oil, 697 physical properties of unused, 695t Capacitive sensing, 475t Carbohydrates, 284, 684 Carbon, 46, 54, 284
285, 674, 684 atoms, 26, 363 backbone, 411
420 Alberta government strategy, 413f Alberta’s plan to implement comprehensive carbon management scheme, 417f CO2 EOR recovery in United States throughout history, 413f CO2 sequestration demonstration projects around world, 418f CO2 supply and demand in Alberta, 411
412 distribution of world’s proven reserve, 419f evolution of CO2 projects and oil prices in United States, 412f key to sustainability in energy management, 419f natural gas production with CO2 injection schemes, 414f oil production rate history for top oil producers, 418f screening criteria for CO2 projects as used in United States, 414t viscosity change invoked by temperature, 419f capture, 404
410 Alberta carbon trunk line, 409f CO2 EOR in oil production, 407f comparison of results, 422t recovery in light oil reservoir, 406f and storage for enhanced oil recovery, 420
423 US experience, 408f contents, 714
715 contrasting and unifying features of, 288t cycle, 846 emissions, 43, 56
57 fixation, 269 hysteria, 842 steel, 797
799 Carbon capture utilization and storage (CCUS), 404 Carbon dioxide (CO2), 4, 33, 92, 112, 155
156, 236
237, 269, 273, 376, 396, 404, 643
644, 674
675, 684, 702, 707, 828 backbone, 416

emissions, 58
59 emissions reduction, 732
733 intensive methane-fed process, 201 reduction routes for acid system, 238f Carbon monoxide (CO), 155
156, 519, 675, 730
731 Carbon nanotubes (CNTs), 215 Carbon
iron mixture, 716 Carbon
oxygen duality, 284
290 characteristic properties of carbon, 285t contrast in reservoir in oxygen and carbon reservoirs, 291t contrasting and unifying features of oxygen and carbon, 288t linked to fire water duality, 291f major organic compounds and functions, 286t natural polymers and bonds, 286t water
food
energy nexus, 284f Carbonyl sulfide (COS), 156 Carboxylic acid, 674 Carnot cycle, 123
124 Cassie’s law, 584
585 Cassie
Baxter equation, 585 Cast iron, 848 Cat crackers, 362 Catalysis development, 201 Catalysts, 112, 199
200, 221
222, 229, 800 zeolite as refining, 249
262 Catalytic cracking process, 185, 223t Catalytic cyclic distillation (CCD), 162, 164 Catalytic nanoparticle-coated ceramic membranes, 219
220 Catalytic reactions, 194
195 Catalytic reforming process, 223t Catalytic synthesis of ammonia, 200 Cathodic polarization theory, 810
811 Cathodic protection, 509, 515, 780 Cathodic reaction, 708 Cathodic surface, 752 Cavitation corrosion, 396 CBM. See Coal bed methane (CBM) CC. See Cloud-to-cloud (CC) CCD. See Catalytic cyclic distillation (CCD) CCTV. See Closed-circuit television (CCTV) CCUS. See Carbon capture utilization and storage (CCUS) CEAA. See Canadian Environmental Assessment Agency (CEAA) Cell cyto-structural neurofilaments, 240
241 Cell elongation, 231
232 Cement, 55
56, 191 Central Intelligence Agency (CIA), 400 Central nervous system (CNS), 632 CER. See Canadian Energy Regulator (CER)

Index

Cesium formate, 704 Cetyl trimethyl ammonium bromide (CTAB), 387 CFD. See Computational fluid dynamics (CFD) CG. See Cloud-to-ground (CG) CGD. See City Gas Distribution (CGD) Chabazite, 249 Charcoal, 729 Charge transfer resistance (Rct), 797
798 Charles law, depiction of, 600f Chaˆtelier’s principle, 197
199 Chemicals, 442
444 catalysts, 519 inhibitors, 816
817 methods, 574, 702
704 reactions, 215
216, 296
297, 736 transformation dehydrogenation, 258
259 China National Petroleum Corporation (CNPC), 24 China Siwei, 404 Chloride ion, 784 Chloride salts, 363 Chloride solutions, 781 Chlorine, 204, 515
516 Chloroform, 574
576 Chloromethane (CHCl3), 111 Chromium, 70
71, 114, 229, 242 concentration, 789
790 ore, 738 Chronic cadmium exposure, 241
242 Chronic methyl mercury exposure, 243 CIA. See Central Intelligence Agency (CIA) CIE chromaticity, 234
235 CIS. See Commonwealth of Independent States (CIS) City Gas Distribution (CGD), 329 Clapeyron equation, 639 “Class II” wells, 436 “Class VI” wells, 436 Classical alkylation processes, 254
255 Clathrate hydrates, 645 Clausius
Clapeyron relation, 150 Clay, 224, 271 minerals, 309 in scientific characterization, 116
121 Climate change, 45
46, 83
84, 348 hysteria, 1 Clinoptilolite, 249 Clive Nisku reservoirs, 409 Closed-circuit television (CCTV), 396
397 Cloud-to-cloud (CC), 307 Cloud-to-ground (CG), 307 lightning flash, 306 CNB. See Convertible nonbiomass (CNB) CNC. See Computer numerical control (CNC)

885

CNG. See Compressed natural gas (CNG) CNPC. See China National Petroleum Corporation (CNPC) CNS. See Central nervous system (CNS) CNTs. See Carbon nanotubes (CNTs) Coal, 62, 79, 92, 200, 529 production, 79 reserve, 42t resources in United States, 42f Coal bed methane (CBM), 528 Coalescence, 369 Coalescing oil/water separators, 559, 559f Coated microscale porous stainless steel mesh, 573 Coating materials, environmental stresses and influence on, 719t Coating systems, 771, 780 Cobalt, 55, 70
71, 246
247 Coking and thermal process, 223t Cold spray coating method, 562 Colloidal CdSe quantum dots, size dependence of energy gap for, 213f Colloidal polymerization, 720 Combined signal-processing method, 485
486 Combustion emissions, 179 Combustion reactions, 156 Commercial Brillouin-based DTS systems, 467 Commercially traded energy sources, 651 Commonwealth of Independent States (CIS), 77
78 Compartmentalization process, 231
232 Compressed natural gas (CNG), 651 Compressibility factor (Z), 433
434 Compression ratio (CR), 426 Compression waves. See Metal shock waves Compressor calculation of, 426
428 power requirements, 427, 428f stations, 321 Computational fluid dynamics (CFD), 496 Computer image analyzer, 687, 688f Computer numerical control (CNC), 473
474 Condensation reactions, 286 Construction solar collector assembly, 693f Contact potential difference. See Volta potential Contamination, 519 Conventional catalysts, 183
185 Conventional Haber
Bosch process, 200 Conventional refining process, 220
221 Conversion method, 176 Convertible nonbiomass (CNB), 130 Cooling process, 267, 296
297 Cooling water systems, 810 Coordinate covalent bond, 204

886

Index

Copper, 11, 70
71, 115, 226, 244, 694, 797 indium, 83
84 metal, 749 reserves, 74t Coprocessing of benzene in naphtha isomerization, 259f Core annular flow (CAF), 357, 384 CORONA program, 400 Coronado Gas Coop, 410 Coronavirus disease, 349 Corporate Average Fuel Economy (CAFE), 348 Correctors, 481
482 Corrosion, 706, 711
736 chemical reactions of, 711f control techniques, 711 corrosion-relevant microbes, 793
794 corrosion-resistant alloys, 762 infrastructure damage caused by, 707f inhibitors, 227 iron, 729
736 blast furnace gas, 731
736 issues, 365 localized corrosion, 780
793 crevice corrosion, 781
782 intergranular, 790
793 pitting corrosion, 782
790 map of United States gas transmission pipeline systems, 709f mechanisms, 361 on metal, 747f microbially influenced corrosion, 793
799 mechanism of microbially influenced corrosion, 796
799 mining and mineral processing, 711
718, 712f chemicals in refining metals, 713t chronology of metal processing, 715t minerals into smartphone, 717f and mitigation, 848 modeling of microbially influenced corrosion, 830
839 pipeline system under modeling, 831f steady-state substrate concentration profiles in the radial direction, 837f pipelines coatings, 718
729 environmental stresses and their influence on coating materials, 719t patents and invention of toxic additives, 721t structure of PVC molecules, 719f potential for metals, 758t protection methods in industry, 801f remedy of microbially influenced corrosion, 799
830 chemicals extracted from natural sources, 812f contemporary narrative and its deconstruction, 818t

corrosion protection methods in industry, 801f extraction processes for plant extracts, 816t microbes involved in corrosion and classification, 807t natural materials as green corrosion inhibitors, 816f plants extracts as corrosion inhibitors for steels in acidic media, 804t rare-earth elements and usefulness, 821t SEM photomicrograph of SRB, 825f science of corrosion, 736
754 distribution of abundant elements in earth crust, 737f natural protection, 743
754 ore minerals and their natural states, 738t sulfides and sulfosalts, 740t types, 710t, 754
793 atmospheric corrosion, 754
761 stress corrosion, 761
780 Corrosion resistance alloys (CRA), 788 COS. See Carbonyl sulfide (COS) Cost of CH4/CO2 mixture separation, 435
436 Couette viscometer, 354 COVID
19, 41
50 effect, 59 CPPIB. See Canada Pension Plan Investment Board (CPPIB) CPT. See Critical pitting temperature (CPT) CR. See Compression ratio (CR) CRA. See Corrosion resistance alloys (CRA) Crack growth, 450 Cracking process, 224 Crassulacean acid metabolism, 269 Cretinism, 242
243 Crevice corrosion, 781
782, 782f Critical pitting temperature (CPT), 790 Critical pressure ratio, 454
455 Critical Reynolds number, 355 Cross-correlation, 457 Cross-flow filtration systems, 562 Crude oils, 13
14, 17, 26, 317
318, 357, 394, 497, 553, 686, 844 broken down into useful and value-added products, 106f composition and properties, 352t formation pathway, 26f, 27f, 176, 177f inherently complex thousands of components in, 3f inventory by site, 503 optical microstructures of crude oil tube two different magnifications, 4f pipeline systems, 319f, 320 refining process, 105, 220
221, 229 Cryogenic storage tanks, 375
376

Index

Crystalline solids, 609, 643
644, 658
659 Crystallization, 579 mechanisms, 360 Crystals, 643
644 CTAB. See Cetyl trimethyl ammonium bromide (CTAB) Cumene, 226 Cumulative counts parameter, 451
453 Cumulonimbus, 303 Cumulus clouds, 303 Current technologies, sustainability status of, 25
38, 27f central role of drilling technology, 31f challenges in waste management, 32
33 crude oil formation pathway, 26f novel desalination technique, 33
38 sustainability analysis of drilling technology, 29f sustainable and unsustainable technology, 28f Cushion gas, 548 Cyanides, 707
708 Cyclic distillation, 164, 164f Cyclization of acyclic compounds, 258
259 Cyclohexane, 226, 564
565 Cylinder, 684
685 assembly, 687f jack, 687f Cylindrical boilers, 335 Cylindrical steel shell, 512 Cylindrical vessels, 516

D D/F. See Distillate-to-feed-ratio (D/F) Dakota Access Pipeline (DAPL), 331 Dakota Gasification Company facility, 404
405 Dalton’s atomic model, 601 Dalton’s law, 601, 634
635 Dalton’s law of partial pressures. See Dalton’s law Daniell cell, 749 DAPL. See Dakota Access Pipeline (DAPL) DAS. See Distributed acoustic sensing (DAS) DCS. See Distributed control systems (DCS) DDI. See Depletion-drive index (DDI) De Broglie wavelength, 624 DEA. See Diethanolamine (DEA) Deadweight tonnes (DWT), 519
520 Deasphalting process, 192 Debris deposition, 784 Decarbonization, 75
76 Decision tree (DT), 463
464 Decoction process, 811
812 DEG. See Diethylene glycol (DEG) “Degenerated” gas, 134
136 Dehydration, 361

887

Dehydrohalogenate, 720 Democritus’ model, 217 Demonstrated reserve base (DRB), 40 Denaturing, 106
107 Denver Unit, 408 Deparaffinization, 192 Depleted gas reservoir, 546
549 gas capacity by storage facility type, 547f location of gas storage operations, 548t Depletion-drive index (DDI), 531 Deposit corrosion, 396 Desulfovıˆbrio alaskensıˆs, 798
799 Desulfovibrio caledoniensis, 797 Desulfovıˆbrio desulfuricans, 798
799, 823 DET. See Direct electron transfer (DET) Detection system, 777 Diatoms, 309 1,2-dichloroethane, 571
572 Dichloromethane (CHCl2Cl), 111 Diesel, 6
7, 323, 395 Diethanol amine, 675 Diethanolamine (DEA), 180
182, 226, 435
436, 672 Diethylene glycol (DEG), 181
182, 361 Digital networking technologies, 392
394, 393f Digital signal processing, 483
486, 484f Dilute pneumatic convey system, 588 Dilution of heavy and extra-heavy crude oils, 361
365 Dimethyl ether (DME), 163, 364 Dimethylformamide, 704 Dinitrogen, crude oil, 702 Diphenyl
diphenyl oxide, 691 Direct detection methods, 468 Direct electron transfer (DET), 807 Direct numerical simulation (DNS), 597
598 Discrete wavelet transform (DWT), 397, 482
483 Dissimilar metal corrosion. See Galvanic corrosion Dissolved formation minerals, 193 Distillate-to-feed-ratio (D/F), 159 Distillation, 106
107, 150, 223t, 635 Distributed acoustic sensing (DAS), 464 Distributed control systems (DCS), 488
489 Distributed temperature sensing (DTS), 464 Disturbances, 486
487 Divided wall columns (DWC), 151
152, 162 DME. See Dimethyl ether (DME) DNA alterations, 229
230 DNS. See Direct numerical simulation (DNS) Dogma “science”, 208
209 Domed external floating roof tank, 514
515 Domestic oil production, 350 Double layer capacitance (Cdl), 797 Downhole cameras, 509 Drag minimization, 358

888

Index

Drag reducing additives, 382
387, 388f Drag reducing agents (DRAs), 383
384 DRAs. See Drag reducing agents (DRAs) Drawdown capability, 504 DRB. See Demonstrated reserve base (DRB) Drilling process, 582
583 technology central role of, 31f sustainability analysis of, 29f Drinking water systems, 706 Droplet size distribution (DSD), 569 Drugs, 800
802 Dry corrosion, 755
759, 756t Dry/wet ratio (D/W), 760 DSD. See Droplet size distribution (DSD) DT. See Decision tree (DT) DTS. See Distributed temperature sensing (DTS) Durbin algorithm, 456 DWC. See Divided wall columns (DWC) DWT. See Deadweight tonnes (DWT); Discrete wavelet transform (DWT) Dye-penetrant testing (PT), 772 Dynamic modeling, 486

E Earth metals, 70
71 Earth Observing System (EOS), 401 Earth Resource Observation Satellites (EROS satellites), 403 EROS A, 404 EROS B, 404 Earthquakes, 706 Eastern Siberia
Pacific Ocean (ESPO), 327 Easy oil, 419
420 EC. See Eddy current (EC) Economic growth, 67
68, 77 Economical liquid desiccant, 361 Eddy current (EC), 396
397, 775 density, 775 testing, 775 EDI. See Expansion drive index (EDI) Edison effect, 206 EDS technique. See Energy dispersive spectroscopy technique (EDS technique) EFAL. See Extra framework aluminum (EFAL) EGR. See Enhanced gas recovery (EGR) EI. See Elongation (EI) EIA. See Energy Information Administration (EIA) EII. See Energy Innovation Index (EII) Einstein’s formula, 264 EKF. See Extended Kalman filter (EKF) Elastic collisions, 603

Electric charge, 624 Electric current, 746 Electric energy, 77 Electric field, 788 Electric fossil fuel energy, 713 Electric load, 543 Electric metal, 339 Electric potential, 746 Electric power, 77 Electric resistance welded carbon steel (ERW carbon steel), 408 Electric resistivity, 755 Electric vehicles (EVs), 52, 56f, 350 Electric-generating capacity, 84 Electrical continuity between two metals, 749f Electrical currents, 745 Electrical force, 618
619 Electrical sensing cables, 446 Electrically heated subsea pipelines, 379
380 Electrically powered alternative, schematic diagram of, 203f Electricity sector, 54 Electride, 200 Electrochemical cell, 794
795 Electrochemical corrosion process, 744 Electrochemical impedance spectroscopy, 475t, 798
799 Electrochemical methods, 759
760 Electrochemical reaction, 705, 736
737, 741 Electrodes, 747
748 surface chemistry, 194
195 Electrolytic corrosion, 743 Electrolytic hydrogen, 768 Electrolytic reactions, 751 Electromagnetic acoustic transducers (EMATs), 396
397, 776
777 Electromagnetic fields, 606 Electromagnetic induction, 775 Electromagnetic radiation, 606 Electromagnetic reflection method, 473
474, 475t Electromagnetic spectrum, 606 Electromagnetic waves, 606 sensor, 473
474 theory of radiation, 137
138 Electron, 208
209, 211, 787 binding energy, 609 in three-dimensional bulk solid, 212f Electron-volt (eV), 608, 626
627 Electron
electron repulsive interactions, 204 Electronic energy levels depending on number of bound atoms, 209f Electrostatic forces, 213
214 Electrum, 714

Index

Elementary processes taking place in fluid catalytic cracking, 255f ELMD. See Ensemble local mean decomposition (ELMD) Elongation (EI), 580 EMATs. See Electromagnetic acoustic transducers (EMATs) Emerging methods, 473
481 examples of operational UAV systems for monitoring oil and gas pipelines, 480t exterior pipeline leak detection methods, 475t visual/biological leak detection methods, 474
481 Eminent domain, 321 Emissions from refinery, 178t, 227t Emulgen, 372 Emulsification, 570 Emulsion polymerization, 719 Energy, 38, 75, 122
125, 264, 588
589 balance equation, 124 bands concept, 209
210 consumption, 44f, 79 change in energy consumption over years, 651f crisis, 48, 65
67 data, 79
80 energy-intensive water splitting process, 201 energy-saving techniques, 732
733 energy-to-mass conversion process, 269 growth of energy sources, 76f per capita, distribution across countries, 85f, 86f policies, 844 prices of different energy commodities, 654t pricing, 50 public perception toward, 68f, 69f redefining, 264
268 sources, 3, 648, 713, 842 comparison of, 78f, 78t system, 650 transfer data, 695
696 usage since industrial revolution, 649f Energy dispersive spectroscopy technique (EDS technique), 796 Energy Information Administration (EIA), 24, 39, 412, 525 Energy Innovation Index (EII), 31
32 Energy Policy and Conservation Act (EPCA), 502
503 Energy Saving Trust, 70 Energy spectrum, 631 modeling, 133
140 artificial and natural lights affect natural material, 140f colors and wavelengths of visible light, 139f frequency
response function, 141f number of particles versus particle size, 139f

889

spectrum of radiation, 137f visible natural colors, 141f wavelength spectrum of visible part of sunlight, 140f Yin
yang in colloquial and scientific terms, 134, 135t Yin
yang representation of matter and energy, 134, 135f reconstituting mass and, 620
634 conventional classification, 620
624 discoveries of subatomic particles, 621t galaxy model, 624
630 Rutherford’s atomic model, 625f scientists and assumptions, 626t useful energy vs. harmful energy, 631
634 Engineered materials, 213 Enhanced gas recovery (EGR), 421 Enhanced oil recovery (EOR), 38, 404, 420
421 Ensemble local mean decomposition (ELMD), 485 Ensemble signal filtering algorithm, 496 Entropy, 604
605 Environmental health, 320
326 compressor stations, 321 eminent domain, 321 erosion and sedimentation, 321 explosions, 322
326 distribution of pipeline products, 325f sequence of petroleum products in a pipeline, 323f land use and forest fragmentation, 321 spills and leaks, 322 Environmental Protection Agency (EPA), 90, 326 Enzymatic reactive distillation (ERD), 157
158 Enzymes, 157
158, 227 EOR. See Enhanced oil recovery (EOR) EOS. See Earth Observing System (EOS) EPA. See Environmental Protection Agency (EPA) EPCA. See Energy Policy and Conservation Act (EPCA) EPS. See Exopolymeric substances (EPS); Extracellular polysaccharides (EPS) ERD. See Enzymatic reactive distillation (ERD) EROS satellites. See Earth Resource Observation Satellites (EROS satellites) Erosion, 321 ERW carbon steel. See Electric resistance welded carbon steel (ERW carbon steel) ESA. See European Space Agency (ESA) ESPO. See Eastern Siberia
Pacific Ocean (ESPO) Essential hydrocarbon fluids, 442
444 Essential oils, 806
807 Ester hydrolysis method, 586 ET. See Evolving Transition (ET) ETBE. See Ethyl tertiary butyl ether (ETBE)

890 Ethane (C2H6), 11, 636, 644, 658
659, 702 Ethanol (EtOH), 157
158 Ethereal oils. See Essential oils Ethoxylated alcohols, 373 Ethoxylated alkyl phenols, 373 Ethyl butyrate (EtBu), 157
158 Ethyl tertiary butyl ether (ETBE), 228t Ethylbenzene, 226 Ethylene, 8
9, 226, 667, 676 sensitivity chart, 677t Ethylene glycol, 670
671, 674, 676
680 ethylene sensitivity chart, 677t oxidation pathway, 182f in alkaline solution, 673f Ethylene oxide, 675
676 Ethylene-vinyl acetate (EVA), 381
382, 382f EU. See European Union (EU) EU Renewable Energy Directive, 75 EUMETSAT, 402 European gas demand, 53 European Space Agency (ESA), 400
401 European Union (EU), 46 eV. See Electron-volt (eV) EVA. See Ethylene-vinyl acetate (EVA) Evolving Transition (ET), 68 EVs. See Electric vehicles (EVs) Exopolymeric substances (EPS), 793
794 Exosphere, 268 Expansion drive index (EDI), 531 Experimental solar trough, 692f solar receiver in focal line of parabolic solar surface, 694f Explosions, 322
326 distribution of pipeline products, 325f sequence of petroleum products in a pipeline, 323f Extended Kalman filter (EKF), 485 Exterior pipeline leak detection methods, 475t Exterior-based leak detection methods, 450
458 acoustic emission sensors, 450
458 leak detection systems, 445f pipeline leakage detection approaches, 449f vibration analysis, 458 External floating roof tank, 514 External methods, 445 Extra framework aluminum (EFAL), 250 Extra-heavy crude oil, 376
379 Extra-heavy crude oil-in-water, 365
374 Extracellular polysaccharides (EPS), 309
311 Extraction methods, 814 process, 192 for plant extracts, 816t solvent, 811

Index

F Fabricated superhydrophilic surfaces, 563 Fabrication, 573 Fabrics, 584
585 Facultative aerobes, 684 Facultative anaerobes, 684 FAME. See Fatty acid methyl esters (FAME) Fanning friction factor (ff), 430 Faraday’s empirical laws of electrolysis, 751 Fast Fourier transform (FFT), 458 Fatty acid methyl esters (FAME), 163 Fatty acids, 367, 683 Faujasites X and Y, 251 Fault detection methods, 459f Fault detection observers, 486
487 Fayalitic slag, 730 FBG. See Fiber Bragg grating (FBG) FBR. See Foreign body response (FBR) FCC. See Fluid catalytic cracking (FCC) FDM. See Filter diagonalization method (FDM) Federal Clean Energy Fund program, 409 Federal EcoETI program, 409 Federal Energy Regulatory Commission (FERC), 320, 508 Federal Reserve system, 50
51 FEM. See Finite Element Modeling (FEM) FERC. See Federal Energy Regulatory Commission (FERC) Fermi energy, 206 Fermi factor expression, 206
207 Fermi gas, 206 Fermi Level, 206 Fermi
Dirac statistics concept, 206 Fermions, 206 Ferritic grains, 769 Fertilizers, 312 FFT. See Fast Fourier transform (FFT) Fiber, 383 Fiber Bragg grating (FBG), 456, 468
469 hoop strain sensors, 444 Fiber optic method, 464
469 electromagnetic spectrum, 465f Fiber optic sensing cable method, 445
446 Fiber optics sensing, 475t Filter diagonalization method (FDM), 458 Filtration, 559 Fine-grained sedimentary rocks, 307
309 Finite Element Modeling (FEM), 137
138, 776 Finite-dimensional system observers, 486
487 Fire in scientific characterization, 116
121 Fixation process, 311 Fixed-roof tank, 512
513 Float gauges, 513

Index

Floating roof tank, 514 Flow assurances, 17
21 analysis, 18
19 flow assurance strategies, 19 optimization strategies, 20
21 prevention strategies, 19 remediation strategies, 19 sampling, 18 scenario modeling, 19 Fluctuations, 332 in API gravity in US refineries, 15f, 16f Fluid catalytic cracking (FCC), 8
9, 255
258, 256f catalysts, 112, 256
257 desulfuration posttreatments, 257
258 elementary processes taking place in, 255f elementary steps assumed to take place in catalytic cracking on zeolites, 256f main parameters that influence catalytic activity of zeolites in fluid catalytic cracking formulations, 257f Fluidized liquid phase, 364 Fluidizing gas, 588
589 Fluids, 668, 670, 846 characteristics and recorded temperature of fluid in different months, 696t density, 355 flow, 332 oscillator, 701 Fluorescence, 475t Fluoride, 242 Fluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS), 562 Food sector, 56 Force, 264 analytical solutions, 208 redefining, 264
268 Foreign body response (FBR), 796
797 Forest fragmentation, 321 Formaldehyde, 321, 674
675 Formate, 182 Formic acid, 674
675 Fortis Alberta, 410 Fossil fuels, 1, 25, 39, 75
77, 84, 176
177, 200, 442
444, 653, 842, 844 consumption, 79 energy, 61 utilization, 25
26 FPC. See Freight Pipeline Company (FPC) Fractional column, pictorial view of, 222f Fractional distillation, 220
221 Fractions, 175
176 Free-electron gas, 210 Freight Pipeline Company (FPC), 345

891

Frequency response at three accelerometer location, 460f Frequency segment power, 457 Frequency-based devices, 263 Fresh plants, 814 Freshwater resources, 278 Friction, 757 Friction reduction, 382
387 annular and core flow for heavy oil pipelining, 387
392 drag reducing additives, 382
387 Fuel consumption, 62, 756 Fuel for electric car, 843f Fuel gases, 4
5 Fugitive emissions, 179 Fused-iron catalysts, 199
200

G Gage hatches, 513 Galactic nuclei, 625
626 Galaxy model, 206
208, 267, 296
297, 304
305, 624
630 configuration of atomic structure in, 629f difference between Planck model and, 629f photoelectric effects with, 630f Rutherford’s atomic model, 625f scientists and assumptions, 626t Galaxy theory of matter, 312 Gallium arsenide, 83
84 Galvanic cell, 745 Galvanic corrosion, 743, 749 Gamma Knife radiosurgery, 632
633 GaoJing-1, 404 Gas, 1
2, 43, 62, 93
103 capacity by storage facility type, 547f China’s economic slowdown, 95
97 natural gas production, consumption, and net import, 96f net oil imports of United States, 96f compression, 771 distribution system, 718 droplet, 554 fundamental considerations of gas separation, 847
848 implosion of Venezuela and Brazil, 98
103 discounts and correlation with political events, 99f gas price, 100f short-term energy, 99f US energy, 102f leak detection techniques, 448, 448f Middle East crisis, 97 particles, 601, 603 pricing, 651
652

892 Gas (Continued) role of, 79
93 energy per capita, distribution across countries, 85f, 86f environmental impact, 92
93 gold price since 1970, 91f historical world energy balances, 80f oil price in recent years, 91f oil prices in history since Second World War until 2018, 88f politics and oil price, 87f useful definitions of sustainability factors, 81t Russia’s expansionism and sanctions, 97
98 oil price in recent years, 98f trade movements, 661f transmission pipelines, 708 transportation of oil and, 846 US energy, 93
95 dry natural gas production, 95f dry shale gas production since 2006, 94f yearly change in unconventional oil and gas, 94f volume of gas from hydrate dissociation in standard condition, 663f war, 100
101, 196 Gas de France Production Netherland, 414
415 Gas hydrates, 643, 646, 657, 698, 700, 848 emerging technologies, 698
704 chemical approach, 702
704 nonchemical approach, 698
702 importance of natural gas, 648
657 change in energy consumption over years, 651f consumption of various natural resources, 656f energy usage since industrial revolution, 649f evolution in global gas reserve in regions, 657f natural gas consumption per capita, 653f per capita energy consumption in world, 652f prices of different energy commodities, 654t review by fuel type, 649t and mitigation, 848 natural gas hydrates, 657
665 natural gas processing, 645f prevention of hydrate formation, 665
670 problems with synthetic chemicals, 670
676 solutions, 676
698 Gas pipelines, 394 systems, 328
331 market concentration, 330f natural gas consumption in recent years, 329f oil and gas pipeline market, 330f types, 394
398 Gas processing, 4
5, 105, 644, 844 background, 105
110 classification of the procedures use by Al-Razi in book of secrets, 106t

Index

refining in 19th century, 111f chemicals used during refining, 111
116 comprehensive mass and energy balance, 122
149 Avalanche theory, 126
129 conventional mass-balance equation incorporating only tangibles, 122f disconnection of origins from process, 147
149 energy, 123
125 energy spectrum modeling, 133
140 law of conservation of mass and energy, 125
126 mass-balance equation incorporating tangibles and intangibles, 123f natural frequency of body parts, 141
147 rebalancing mass and energy, 122
123 simultaneous characterization of matter and energy, 130
133 tangible/intangible conundrum or yin
yang cycle, 149 pathways, 180
183 of glycol and amines, 181
183 natural gas “well-to-wheel” pathway, 181f natural gas processing methods, 181f refining and, 175
183 sustainable development, 183
189 technology, 846 water, air, clay, and fire in scientific characterization, 116
121 Gas storage, 509, 523
551 history of “open access” to storage capacity, 523
525, 534
535 owners and operators of storage facilities, 532
534 storage measures, 526
532, 530f underground natural gas storage data, 525, 535
539 pipeline capacity, 549
551 regional prices, 544
545, 545f storage measures, 535 total natural gas storage capacity, 535
539, 537f, 538f US demand and supply balance, 540
544, 540f, 541f value of storage and storage capacity additions, 545
549 Gaseous hydrocarbons, 505, 700 Gas
gas mixing, 415 Gas
gas separation, 219
220 Gasholders, 549
550 Gasification, 154
155, 155f hydrogen supply unit, 408 Gas
oil interface, 555
556 Gas
oil ratio (GOR), 554 Gas
oil separation, 848 Gasoline, 6
7, 11
12, 15, 94, 100, 323, 395, 720 pool, 252
253 streams contributing to gasoline pools, 253f

Index

Gathering pipelines, 394 Gauge bosons, 622 Gauges plate, 685 Gay-Lussac’s Law, 601
602 Gay-Lussac’s observations, 601 GDP. See Gross domestic product (GDP) GeoEye, 402 GeoEye-1 satellite, 402 Geographical information system (GIS), 394 Geohazards, 400, 410 Geologic diversity, 509 Geologic site characterization, 434 Geophones, 453, 455
456 GHGs. See Greenhouse gases (GHGs) GIS. See Geographical information system (GIS) Glacial acetic acid, 703 Glass fibers, 54 Global carbon cycle, 646 Global consumption, fractions of different energy sources on, 64f Global energy, 58
59, 73
74 consumption, 63f Global gas reserve in regions, Evolution in, 657f Global gas storage capacity, 551f Global natural gas, 101 Global oil, 497, 847 inventory, 847 production, 84 Global petroleum, 85
86, 317 Global Positioning System (GPS), 495 Global power generation, 65f, 66f Global storage capacity, 550
551, 551f Global warming, 46, 67, 83
84 Glycolate, 182, 673 Glycols, 361, 647, 667 aldehyde, 673 dehydration, 180
181 ethers, 182, 704 pathways of, 181
183 Goethite (FeO(OH)), 199
200 GoldSim environment, 423 GOR. See Gas
oil ratio (GOR) GPS. See Global Positioning System (GPS) Grand Unified Theories (GUTs), 623 Grand Unified Theory model (GUT model), 624 Graphite, 70
71 Gravity oil/water separator, 558
559, 558f Gravity separation, 554
560, 712 benefits of oil/water separator, 559
560 difference between horizontal and vertical separators, 560t Stoke’s law configuration, 568f typical crude oil characteristics, 569t

893

horizontal well separator, 556f separation in horizontal separator, 554f types of oil/water separators, 558
559 coalescing oil/water separators, 559 gravity oil/water separators or API separators, 558
559 vertical separator, 557f Gravity-driven filtration, 562 Green algae, 309
311 Green corrosion inhibitors, 800
802 Green energy, 70
71, 92
93 Green organic compounds, 814 Green revolution, 195
196 Green technology, 842 Greenhouse gases (GHGs), 58
59, 321, 643 emissions, 58
59, 75
76, 90 Gross domestic product (GDP), 706 Ground flashes, 300
301 Ground penetration radar, 475t Groundwater composition, 765 GUT model. See Grand Unified Theory model (GUT model) GUTs. See Grand Unified Theories (GUTs)

H Haber process, 195
203, 844
845 basic flow diagram of Haber
Bosch process, 199f graphical overview of strategies to improve Haber
Bosch ammonia synthesis, 202f schematic diagram of typical conventional methanefed Haber
Bosch process and electrically powered alternative, 203f world fertilizer use, projected until 2030, 198f world rise in millions of metric tons of N in fertilizer, 196f, 197f Haber
Bosch ammonia synthesis, graphical overview of strategies to improve, 202f Haber
Bosch loop, 202
203 Haber
Bosch process, 313
314 basic flow diagram of, 199f Halogenated hydrocarbons, 111 Hardware-based methods, 445, 447
448 Harmful energy, useful energy vs., 631
634 Hatch
Slack photosynthetic cycle, 269 HAZ. See Heat-affected zone (HAZ) Hazardous liquid pipelines, 765 Hazardous waste, 519 HD. See Huntington disease (HD) HDPE. See High-density polyethylene (HDPE) HDS. See High-fidelity dynamic sensing (HDS) Heat, 266 Heat capacity, 604 “Heat death” of universe, 125

894

Index

Heat mass integration (HMI), 151
152 Heat storage systems, 692 Heat-affected zone (HAZ), 790
791 Heated pipelines, 376
379 Heating heavy pipelines, 376
379 kerosene on crude oil viscosity, 378f viscosity behavior for W/O emulsions, 377f Heating processes, 226
227, 846 Heaviside function, 599 Heavy aromatic naphtha, 224
226 Heavy metals, 25
26, 229, 360 Heavy microbial colonization, 825 Heavy oil, 846 emulsions for transport in cold environments, 375
376 transportation, 846 Helical pipe viscometer, 355 Helium fraction, 5
6 Hematite (Fe2O3), 199
200 Henry’s law, 635 Heptane, 364, 702 Heteroatoms, 352 Heterogeneous atoms, 11 Heterogeneous surfaces, 585 Heulandite, 249 Hexadecane, 564
565 Hexane, 702 Hexavalent chromium, 242 HF. See Hydrofluoric acid (HF) Hidden Markov model (HMM), 456 Higgs particle, 264
265 High altitude clouds, 300
301 High boiling point hydrocarbons, 262 High-density polyethylene (HDPE), 450
451 High-fidelity dynamic sensing (HDS), 399 High-pressure steam, 202
203 High-resolution inductively coupled plasma mass spectrometry (HRICPMS), 309
311 Hilbert transform, 485 HLB. See Hydrophilic
lipophilic balance (HLB) HMI. See Heat mass integration (HMI) HMM. See Hidden Markov model (HMM) Homo sapiens, 265 Homogeneous system, 352
354, 785
786 Homogenization, 366, 570 Honey-Sugar-Saccharine-Aspartame (HSSA), 2, 841 Horizontal pipes, 385
386 Horizontal tanks, 512, 515 Hot fluid, 697 Hot tap connection, 411 Hough transform, 477
480 HRICPMS. See High-resolution inductively coupled plasma mass spectrometry (HRICPMS)

HSSA. See Honey-Sugar-Saccharine-Aspartame (HSSA) Human enzymes, 243 Huntington disease (HD), 632 Hurricanes, 532 Huygens, 605 Hybrid inorganic
organic nanocomposite membranes, 219
220 Hybrid observers, 486
487 Hybrid protein
polymer biomimetic membranes, 219
220 Hydrates, 643, 657 blockage removal process, 662 crystal, 669 formation, 669, 842 low-dosage hydrate inhibitors, 667
670 prevention of, 665
670, 666f prevention through biological means, 682
683 thermodynamic inhibitors, 667 grains, 670 inhibition system, 666 inhibitors, 666
667 particles, 701 phase boundary for natural gas system, 662f plugs, 661, 667 problems related to formation of, 661
665 details of thermodynamic inhibitor injection into long windowed rig, 663t hydrate phase boundary for natural gas system, 662f temperature profile for different sections, 664f volume of gas from hydrate dissociation, 663f sediments, 646 solar irradiation for, 691
698, 693f solids, 643 Hydraulic jack, 687f Hydraulic velocity, 831 Hydrides, 200, 278
281 Hydro processing, 223t Hydrocarbons, 3, 97, 351
352, 364, 519, 643, 658
659, 684 components, 351 crude, 370
371 diluents, 367 droplets, 373 fluids, 698
703 hydrates, 643
644 liquids, 340 lumps, 682 molecules, 643
644 phase behaviour, 636 stream, 385
386 Hydrochloric acid (HCl), 111
112, 361
362, 702

Index

Hydrocracking, 259
262 catalysts, 112 diagram of single-stage and two-stage hydrocracking process, 260f elementary steps occurring simultaneously during hydrocracking, 260f molecular traffic of gas oil through 18 membered ring channels, 262f Hydrodynamic radius, 381 Hydrodynamic trapping, 415 Hydrofluoric acid (HF), 226
227 Hydrogel-coated mesh, 573 Hydrogen (H2), 155
156, 201
202, 278
281, 674, 730 bond, 364 contrasting properties of, 278
283 opposing properties of, 280t phase diagram of hydrogen, 281f similar and contrasting properties of, 282t gas, 603 Hydrogen chloride (HCl), 156, 750
751 Hydrogen cyanide (HCN), 156 Hydrogen fluoride. See Hydrofluoric acid (HF) Hydrogen sulfide (H2S), 33, 156, 519, 643
644, 702 Hydrogenation, 239 Hydrolysis process, 785 Hydrolyzed surface, 586 Hydrophilicity, 565 Hydrophilic
lipophilic balance (HLB), 374 Hydrophobic
oleophilic materials, 561 Hydrostatic pressure, 566 Hydrostatic test, 779 Hydrothermal treatments, 562 Hydrotreaters, 362 Hydrotreating catalysts, 112 Hydrotreating process, 9 Hydrous ferrous oxide, 744
745 Hydroxide minerals, 739 Hydroxyl groups, 574 Hypothetical graviton, 622

I IARC. See International Agency for Research on Cancer (IARC) IC. See Intra-cloud (IC) ICA. See Independent component analysis (ICA) ICEs. See Internal combustion engines (ICEs) Ideal gases, 123
124 law, 600
605 depiction of Boyle’s law, 601f depiction of Charles law, 600f internal energy, 604
605 in microscopic scale, 610
620 IEA. See International Energy Agency (IEA)

895

IEO2021. See International Energy Outlook 2021 (IEO2021) IGC. See Intergranular corrosion (IGC) ILI. See In-line inspection (ILI) ImageSat international, 403
404 Imaging technology, 215 IMF. See International Monetary Fund (IMF) Impedance method, 463 In-line inspection (ILI), 396
397, 772 Independent component analysis (ICA), 483 Independent storage service providers, 550 Indirect detection methods, 468 Industrial revolution, energy usage since, 649f Inflection point, 481
482 Infrared radiation (IR), 606 Infrared therapy, 632 Infrared thermography (IRT), 469
473, 475t basic functions, 471f experimental setup, 471f Injection costs, 434
435 Inorganic contaminants found in groundwater, 117t Intangible conundrum, 149 Intangible mass, 122 Integer programming (IP), 170 Intellectual approach, 106
107 Interface tracking approach, 598
599 Interface-resolved modeling, 596
597 Intergranular corrosion (IGC), 790
793 corrosion, sustainability, and processing of metal, 791f source of corrosion, 794f Interior pipeline leak detection methods, 488t Interior/computational methods, 481
486 digital signal processing, 483
486 mass-volume balance, 481
482 NPWs, 482
483 PPA, 483 Intermediate species, 237 Internal combustion engines (ICEs), 55 Internal energy, 604
605 Internal floating roof tank, 514 International Agency for Research on Cancer (IARC), 728
729 International Energy Agency (IEA), 24, 98, 329 International Energy Outlook 2021 (IEO2021), 64 International Monetary Fund (IMF), 41
42 International Organization for Standardization (ISO), 320 International System of units (SI), 211 Internet protocol (IP), 392 Internuclear distance for interaction between two gaseous hydrogen atoms, plot of, 205f Interrogation methods, 457

896

Index

Intra-cloud (IC), 307 Intrinsic nanopores, 573 Iodine, 242
243 Ionic species, 761
762 Ionization energy, 281 IP. See Integer programming (IP); Internet protocol (IP) IR. See Infrared radiation (IR) Iron (Fe), 11, 115
116, 246
247, 717
718, 729
736, 750
751 blast furnace gas, 731
736 iron-rich meteorites, 716
717 iron
carbon alloys, 716 metalworking technology, 716
717 ore, 70
71 Iron oxides, 199 minerals, 705
706 reduction, 731 IRT. See Infrared thermography (IRT) Isentropic flow relation, 454
455 ISO. See International Organization for Standardization (ISO) Isobutane solubility, 254
255 Isobutane
butene alkylation, 254
255, 254f Isomerization, 186 of linear alkanes, 253
254 process, 9, 258
259 Isoporous block copolymer membranes, 219
220 Itai-itai, 241
242 Iterative method, 430

J J-space systems. See Japan Space Systems (J-space systems) Japan Space Systems (J-space systems), 401 JIP. See Joint Industry and Project (JIP) Joint Industry and Project (JIP), 491
492 Joule’s second law, 604 Jurassic sandstone, 714

K Kalman filter (KF), 482
483 Kantorovich distance concept, 444 Kaolinite, 309
311 Kazakhstan
China pipeline, 327 Kerosene, 6
7 concentration, 378 on crude oil viscosity, 378f Keshan disease, 244 Ketones, 720 Keystone XL, 327 KF. See Kalman filter (KF) KHIs. See Kinetic hydrate inhibitors (KHIs) Kinetic energy, 601
602, 608
609

Kinetic hydrate inhibitors (KHIs), 667
669 Kolmogorov length scale, 598 KTI, 410 Kyoto Protocol, 92

L Labor, 435 Laboratory tests, 561 Land use fragmentation, 321 Landsat, 400 Landslides, 400, 410 Langmuir adsorption, 195, 203
207, 204f, 205f, 207f Langmuir kinetic studies, 846 Langmuir’s kinetic studies, 204 Large pipeline projects, 326
328 Eastern Siberia
Pacific Ocean pipeline, 327 Kazakhstan
China pipeline, 327 Keystone XL, 327 Rockies Express pipeline, 327
328 Trans-Mediterranean natural gas pipeline, 328 West-East pipeline project, 326 Wloclawek gas compressor station, 326 Large pore acid zeolites, 262 Lauryl ether, 372 Law of conservation of energy, 125
126 Law of Conservation of Mass, 123, 125
126 Law of Conservation of Matter, 122 Layer-by-layer coating, 562 LCD. See Liquid crystal display (LCD) LDCs. See Local distribution companies (LDCs) LDHIs. See Low dosage hydrate inhibitors (LDHIs) LDRs. See Light dependent resistors (LDRs) LEACH. See Low energy adaptive clustering hierarchy (LEACH) Lead, 114, 229, 236
239, 243 CO2 reduction routes commonly proposed for acid system, 238f equilibrium potentials for various CO2 electroreduction reactions, 238t SPAIR spectra on Pb electrode after bubbling CO2, 239f, 240f Lead-acid batteries, 54 Leak detection index, 463 performance comparison of leak detection technologies, 488
490 interior pipeline leak detection methods, 488t three level performance analysis comparison, 489f two-level performance analysis comparison, 491t Leak noise signals, 484 Leakage, 458 detection of heat pipe network, 468 Leaks, 322

Index

LEDs. See Light emitting diodes (LEDs) Leduc field reservoirs, 409 Legumes, 312 Leptons, 622, 628 Lewis dot symbols, 205 Lewis electron structure, for H2O, 205 Lewis structure, for H2O, 205 Lie´nard-type model, 487 Light dependent resistors (LDRs), 397 Light detection and ranging (Lidar), 473, 475t LiDAR-based 3D point cloud measuring system, 473 Light emitting diodes (LEDs), 397 Light therapy (LT), 604, 632 Lightening, 300
301 science of, 291
307 Lighter petroleum, 357 Limestone, 730 Limonite (FeO(OH). n(H2O)), 199
200 Linear paraffin isomerization, 253
254 Linear prediction cepstrum coefficient (LPCC), 456 Lipase B from yeast Candida antarctica (CalB), 158
159 Lipids, 284 Lipopolysaccharides, 374 Liposomes, 245
246 Liquefied natural gas (LNG), 46, 506, 651 storage tank, 519 tankers, 318 Liquefied petroleum gas (LPG), 487
488, 651 Liquid, 505 coatings, 718 component concentrations, 634 contaminants, 519 crystal microstructure, 384 droplets, 557
558 flow, 555
556 period, 164 fuels, 317
318, 497
498 monthly history of liquid fuel consumption, 498f hydrocarbons, 33, 361, 379, 385, 670 metal, 718 petroleum, 350 pipelines, 319 sensing cables, 446 spills, 322 surface, 514 tension, 594 Liquid crystal display (LCD), 717
718 Liquid
gas separation, 555
556 Liquid
liquid interface, 557
558 Lithium, 55, 70
71 Lithium-ion batteries, 54 LNG. See Liquefied natural gas (LNG) Local coverage, 491
492

897

Local distribution companies (LDCs), 508 Logical absurdities, 209
210 Lone pairs, 204 Low dosage hydrate inhibitors (LDHIs), 667
668 Low energy adaptive clustering hierarchy (LEACH), 494 Low-carbon energy, 77 Low-dosage hydrate inhibitors, 667
670 antiagglomerants, 670 kinetic hydrate inhibitors, 668
669 Low-level clouds, 303 LPCC. See Linear prediction cepstrum coefficient (LPCC) LPG. See Liquefied petroleum gas (LPG) LT. See Light therapy (LT) Lubricants, 720 Lubricity of various artificial fluids as function of viscosity, 219f Luenberger-based observers, 486
487 Lung cancer, 728
729 Lung carcinogenesis, 729

M Macronutrients, 287
290 Magnesium (Mg), 361, 752 Magnesium chloride (MgCl2), 707, 751 Magnetic elements, 246
247 Magnetic field (MF), 633, 775 Magnetic flux leakage (MFL), 396
397, 509 Magnetic particle imaging, 246
247 Magnetic particle testing (MT), 772 Magnetic permeability, 775 Magnetic resonance imaging (MRI), 246
247, 633 Magnetic sensing, 246
247 Magnetism, 213
214 Magnetite (Fe3O4), 199
200, 742 Magnitude, 775 Malthusian theory, 50
51 Management information system (MIS), 394 Manganese, 116, 243 Manual detection, 447 Manure, 312 MAOP. See Maximum allowable operating pressure (MAOP) Marathon oil, 504 Marcellus Shale formations, 421 Maskless laser nano-lithographic technique, 580 Mass, 122
123 conservation equations, 591, 744 conservation theory, 122 Mass-volume balance, 481
482 Material balance equation (MBE), 531 Material process, 844

898 Material processing in pre-industrial era, 848 Material resources characteristic speed act as function physical state of matter, 270f nature of, 270
271 Matter-wave duality, 211
212 Maxar, 402
403 Maximum allowable operating pressure (MAOP), 771 Maxwell’s equation, 303 Maxwell’s formula, 264 Maxwell’s speed distribution, 611 MBE. See Material balance equation (MBE) MCP. See Mechanical contact probe (MCP) MCSs. See Mesoscale convective systems (MCSs) MD simulations. See Molecular dynamics simulations (MD simulations) MDGs. See Millennium Development Goals (MDGs) MEA. See Methanolamines (MEA) Mean square error (MSE), 444 Mechanical calipers, 509 Mechanical contact probe (MCP), 396
397 Mechanical integrity tests, well operating and, 434 Mediated electron transport (MET), 807 Medina production, 109
110 Medium pore zeolites, 251 Medium range (MR), 521 MEG. See Monoethylene glycol (MEG) Megaelectron volts (MeV), 627 MEK. See Methyl ethyl ketone (MEK) Melt hydrates, 663
664 Membrane filtering techniques, 562 Membrane technologies, 561 Mercury, 107, 115, 226, 229, 243 Mesoscale convective systems (MCSs), 302 MET. See Mediated electron transport (MET) Metal corrosion, environmental causes of, 743f Metal electrodes, 236 Metal processing technology, 848 Metal shock waves, 764 Metal spalling process, 762
764 Metal sulfides, 261 Metal surface, 361, 382, 736
737 Metal-organic framework (MOF), 232 Metallic cations, 785
786 Metallic crystal, 788 Metals, 226, 352, 848 Meteosat, 402 Meteosat visible and infrared imager (MVIRI), 402 Methanation reaction, 156 Methane (CH4), 11, 155
156, 208
209, 636, 643, 658
659, 666, 690, 702 bubble formation, 642 methane-fed process, 201

Index

molecule forms, 657 system, 685 tank, 690 assembly, 686f Methane hydrates, 646, 698 Methanol, 226, 667
669, 674, 676 combustion of, 674 oxidation of, 673
674 Methanol, oxidation of, 674 Methanolamines (MEA), 180
181 Methyl ethyl ketone (MEK), 228t, 360 Methyl tertiary butyl ether (MTBE), 228t METI. See Ministry of Economy, Trade and Industry (METI) MeV. See Megaelectron volts (MeV) MF. See Magnetic field (MF) MFL. See Magnetic flux leakage (MFL) MHWS. See Microholes-through wood sheet (MHWS) MI. See Monitoring index (MI) MIC. See Microbially influenced corrosion (MIC) Micro-organisms, 682 Microbes, 796
797, 807, 807t Microbially influenced corrosion (MIC), 782, 793
799 mechanism of, 796
799 aluminium
magnesium alloy, 797
798 carbon steel, 798
799 carbon steel, copper, and aluminium, 797 titanium, 796
797 modeling of, 830
839 pipeline system under modeling, 831f steady-state substrate concentration profiles in radial direction, 837f remedy of, 799
830 chemicals extracted from natural sources, 812f contemporary narrative and its deconstruction, 818t corrosion protection methods in industry, 801f extraction processes for plant extracts, 816t microbes involved in corrosion and classification, 807t natural materials as green corrosion inhibitors, 816f plants extracts as corrosion inhibitors for steels in acidic media, 804t rare-earth elements and usefulness, 821t SEM photomicrograph of SRB, 825f Microholes-through wood sheet (MHWS), 583
584 Microorganisms, 794 Micropapillae, 571
572 Micropores, 249 Microscopic scale correlation between frequency and color, 616f firework, 615f

Index

ideal gas law in, 610
620 molecule numbers vs. associated speed, 611f quark-gluon plasma of early universe, 619f scale considerations in subatomic to mega scale, 613f solar radiation spectrum, 617f Microvoid coalescence, 769
771 Microwave
assisted reactive distillation (MRD), 157 Milk casein phosphoproteins, 240
241 Millennium Development Goals (MDGs), 95
97 Million British thermal units (MMBtu), 101
102 Million cubic feet per day (MMcf/d), 526, 536 Mineral nutrition, 231
232 Mineral particles, 736 Mineral processing, 711
718, 712f, 733 chemicals in refining metals, 713t chronology of metal processing, 715t minerals into smartphone, 717f Mineral resources, 717
718 Mineral zeolites, 249 Mineralized tissues, 242 Mining processing, 711
718 chemicals in refining metals, 713t chronology of metal processing, 715t minerals into smartphone, 717f Ministry of Economy, Trade and Industry (METI), 401 MINLP. See Mixed integer nonlinear programming problem (MINLP) MIS. See Management information system (MIS) Miscroscopic observation of droplet size evolution, 370f Mitigation, corrosion and, 848 Mitigation, gas hydrate and, 848 Mixed integer nonlinear programming problem (MINLP), 170 MMBtu. See Million British thermal units (MMBtu) MO. See Molecular orbitals (MO) Modal analysis, 146 MODIS, 400 MOF. See Metal-organic framework (MOF) Molecular dynamics simulations (MD simulations), 642 Molecular orbitals (MO), 208
209 Molecules, photoemission from, 609
610 Molybdenum, 243, 789 Monitoring during CO2 injection, 434 Monitoring index (MI), 463
464 Monod equation, 832
833 Monodirectional zeolites, 251 Monoethanolamine (MEA), 181
182, 670
671, 674
675, 681 degradation of, 675f Monoethylene glycol (MEG), 361 Monthly history of liquid fuel consumption, 498f Montmorillonite, 309
311

899

Moon shot, 31
32 Moratorium, 346 Mordenite, 251 Motion of phase interface, 598
600 MR. See Medium range (MR) MRD. See Microwave
assisted reactive distillation (MRD) MRI. See Magnetic resonance imaging (MRI) MSE. See Mean square error (MSE) MTBE. See Methyl tertiary butyl ether (MTBE) Multiregression analysis, 444 MVIRI. See Meteosat visible and infrared imager (MVIRI)

N Naı¨ve Bayes (NB), 463
464 Nanocapsules, 245
246 Nanocrystals, 209
210 Nanomaterials, 219
220, 595 Nanoparticles, 213, 219
220, 595 Nanoscale, 565
566 phenomenon, 215, 246 pores, 573 science of, 244
249 estimates of revenues from nanotechnology applications in United States, 247f Nanoscience, 215 Nanostructured copper substrates, 573 Nanostructured hydrogel, 573 Nanotechnology, 214
215, 246 Nanotubes, 245 Nanowire copper mesh, mechanism involved in, 573f Nanowire-hair microstructure, 573 Nanowires, 245 Naphtenic acids, 369 Naphtha, 15 Naphthalene, 226 Naphthenic acids, 357 National Nanotechnology Initiative, 246 National Transportation Safety Board (NTSB), 765 Natrolite, 249 Natural chemicals, 187f aluminum, 241f benefits of, 240
244 Natural CO2 cycle, 846 Natural disasters, 320 Natural frequency of body parts, 141
147 absorption coefficient for water from microwaves to UV, 144f decreased survival of HL60 cells after fractionated irradiation, 147f dielectric constants of kinds of food, 145f effects of microwave treatments on organoleptic quality of yak meat, 143f

900

Index

Natural frequency of body parts (Continued) mean natural frequencies for normal and breast cancer cells, 145t mean natural frequencies for normal and prostate cancer cells, 145t Natural gas, 3
4, 43, 78
79, 84
85, 92, 102
103, 109, 196, 200, 317, 499
500, 643, 666, 682, 706 condensates, 365 consumption per capita, 653f in recent years, 329f fields, 505 hydrate phase boundary for natural gas system, 662f importance of, 648
657 pipelines, 319
320, 657 processing, 229, 848 chemicals and natural gas relationship, 673
676 methods, 181f source, 645f production, 415 consumption, and net import, 96f reservoirs, 415 storage, 505
511, 548 schematic of natural gas storage sites, 507f storage and withdrawal of natural gas during year, 506f underground natural gas storage data, 525 underground storage and withdrawal in United States, 507f transmission systems, 646 “well-to-wheel” pathway, 181f during year, storage and withdrawal of, 506f Natural gas hydrates, 643, 645, 657
665, 658f, 669, 699 formation, 658
661 consumption of, 659f major gas trade movements, 661f oil trade movement, 660f problems related to formation of hydrates, 661
665 Natural gas liquids (NGL), 6f, 45, 320 Natural Gas Policy Act (NGPA), 100
101, 346 Natural hazards, 706 Natural light, 266 Natural materials, 224, 579, 815, 844, 848 as green corrosion inhibitors, 816f Natural polymers, 286, 286t Natural processes, 217, 224, 604
605, 844, 845f Natural products, 820 Natural protection, 743
754 corrosion on metal, 747f dissolved oxygen on corrosion of mild steel in acids, 748t electrical continuity between two metals, 749f environmental causes of metal corrosion, 743f

Natural resources, consumption of, 656f Natural units of clay materials, 309
311 Natural water-borne nanoparticles, 249 Natural zeolites, 252 Navier
Stokes equations, 597 NB. See Naı¨ve Bayes (NB) NCNB. See Nonconvertible nonbiomass (NCNB) NDE techniques. See Nondestructive evaluation techniques (NDE techniques) NDs. See Neurodegenerative diseases (NDs) Negative pressure waves (NPWs), 482
483 Neodymium, 70
71 Neurodegenerative diseases (NDs), 632 Neutral water, 752 Neutralization, 785 Neutrinos, 264
265, 628 New Science, 208, 217, 245, 265, 270
271 New world order for petroleum, 50
68 battery electric vehicles worldwide, 57f EIA, 68f electric vehicle manufacturing, 56f fractions of different energy sources on global consumption, 64f fuel shares of primary energy and contributions to growth, 65t global energy consumption, 63f global power generation, 65f, 66f growth in oil demand, 58f public perception toward energy sources, 68f, 69f supply and demand in 2020, 60f world fossil fuel consumption, 62f Newton’s law of viscosity, 569 Newton’s Laws, 264 Newton’s Laws of Motion, 126 NGL. See Natural gas liquids (NGL) NGPA. See Natural Gas Policy Act (NGPA) Nickel, 11, 55, 70
71, 115, 226, 243
244, 246
247, 694, 781 nickel-based batteries, 54 Ni
Cr
Fe alloys, 792 Nikuradse friction factor correlation, 433 Nitrate (NO3), 287
290, 312 mineral, 312 Nitric acid (HNO3), 312 Nitric oxide (NO), 312 Nitride, 200 Nitrogen (N), 5
7, 156, 257, 360, 643
644, 684, 707
708 compounds, 111, 644 cycle, 307
316, 311f contrasting and unifying characters of oxygen and nitrogen, 308t

Index

long term variation of amount of N internationally traded throughout world, 315f production of sustainable and unsustainable ammonia, 310f Yin
Yang behavior in natural elemental “particles”, 310f fertilizer, 56 fixation, 311
312 metabolism, 231
232 nitrogen-fixing crops, 312 part of nitrogen duality, 307
316 Nitrogen dioxide (NO2), 312 Nitrogen oxides (NOX), 321, 519, 675 Nitrogen rejection unit (NRU), 5, 6f Nitrogenous zeolites, 252 Nitrous oxide (NO), 112 NMR. See Nuclear magnetic resonance (NMR) No-flaring method, 189 Noble metals, 261 nanoparticles, 220 Noctilucent clouds, 300
301 Nonamyloid components, 240
241 Nonane, 702 Nonchemical approach, 698
702 Nonconvertible nonbiomass (NCNB), 130 Nondestructive evaluation techniques (NDE techniques), 772
773, 780 Nonfossil fuel energy, 67
68 Nongglomerating hydrate particles, 700 Nonhydrocarbons, 643
644 Nonhydrocarbons process, treating, 223t Nonluminous flame, 674 Nonorganic ethyl alcohol, 35 Nonorganic liquids, 511 Nontechnical leak detection methods, 448 Nontechnical methods, 444
445 Nontoxic thermal oils, 691 North West Redwater (NWR), 406 North West Redwater Partnership Sturgeon Refinery (NWRPSR), 406 Novel desalination technique, 33
38, 36f, 37f NP-complete, 494 NPWs. See Negative pressure waves (NPWs) NRU. See Nitrogen rejection unit (NRU) NTSB. See National Transportation Safety Board (NTSB) Nuclear, 648
649 Nuclear energy, 61, 69, 79, 83
84 Nuclear Industry Association, 69 Nuclear magnetic resonance (NMR), 570, 712 Nuclear reactor vessels, 515
516 Nucleic acids, 284 Nucleons, 626

901

Nucleus, 612
613 Nutrients, 684 NWR. See North West Redwater (NWR) NWRPSR. See North West Redwater Partnership Sturgeon Refinery (NWRPSR)

O O/W. See Oil in water (O/W) O/W/O. See Oil-in-water-in-oil (O/W/O) Obligate aerobes, 684 Obligate anaerobes, 684 OBMs. See Oil-based muds (OBMs) OCA. See Oil contact angle (OCA) OCP. See Open circuit potential (OCP) Octane, 702 Octylphenol ethoxylates, 366 OD. See Outer diameter (OD) Odorless, 505 OECD. See Organisation for Economic Co-operation and Development (OECD) Office of Pipeline Safety (OPS), 765 OFS. See Optical fiber sensor (OFS) Ohm’s law, 746 Oil, 1
2, 17, 43, 77, 84, 92
103, 554 China’s economic slowdown, 95
97 energy per capita, distribution across countries, 85f, 86f environmental impact, 92
93 gold price since 1970, 91f historical world energy balances, 80f implosion of Venezuela and Brazil, 98
103 Middle East crisis, 97 oil price in recent years, 91f oil prices in history since Second World War until 2018, 88f politics and oil price, 87f role of, 79
93 Russia’s expansionism and sanctions, 97
98 some useful definitions of sustainability factors, 81t transportation of, 846 US energy, 93
95 dry natural gas production, 95f dry shale gas production since 2006, 94f yearly change in unconventional oil and gas, 94f Oil and gas pipeline market, 330f yearly change in unconventional, 94f Oil and gas separation gravity separation, 554
560 benefits of oil/water separator, 559
560 types of oil/water separators, 558
559 ideal gas law, 600
605 depiction of Boyle’s law, 601f

902 Oil and gas separation (Continued) depiction of Charles law, 600f internal energy, 604
605 oil
water separation, 561
587 RD requires overlap of operating windows for reaction and separation, 554f reconstituting mass and energy spectrum, 620
634 conventional classification, 620
624 “discoveries” of subatomic particles, 621t galaxy model, 624
630 useful energy vs. harmful energy, 631
634 sand jets and drains, 587
591 determination of jet boundary via thermocouples, 589f evaporative liquid nitrogen jet in air, 588f horizontal separator fitted with sand jets, 587f solids concentration on spray jet evaporation, 589f subatomic representation, 605
620 electromagnetic field, 605f electromagnetic spectrum, 607f ideal gas law in microscopic scale, 610
620 photoelectric effect, 607f photoemission from atoms, molecules, and solids, 609
610 vapor/liquid separation, 591
600 aerosols, 592
597 direct numerical simulation of primary atomization, 597
598 length and time scales, 598 motion of phase interface, 598
600 vapour
liquid equilibria, 634
642 Oil compounds, 193 Oil consumption, 84, 346 Oil contact angle (OCA), 571
572 and oil sliding angles for droplet, 577f Oil dehydration, 571 Oil gas, 317 Oil glut, 519 Oil in water (O/W), 366 Oil mergers, 347 Oil pipelines crude oil composition and their properties, 352t electrically heated subsea pipelines, 379
380, 380f flow rate vs. diameter, 353f heavy crude, 350
392 pour point depressants, 380
382, 381f, 382f reducing friction, 382
387 annular and core flow for heavy oil pipelining, 387
392 drag reducing additives, 382
387 stress
strain relationship for various fluids, 353f types, 394
398 viscosity reduction, 361
379

Index

dilution of heavy and extra-heavy crude oils, 361
365 formation of heavy and extra-heavy crude oil-inwater, 365
374, 365f, 368f heating heavy and extra-heavy crude oil and heated pipelines, 376
379 heavy oil emulsions for transport in cold environments, 375
376 Oil pipelining, annular and core flow for heavy, 387
392 Oil processing, 105 atmospheric and vacuum distillation, 150
174 background, 105
110 classification of the procedures use by Al-Razi in book of secrets, 106t refining in 19th century, 111f chemicals used during refining, 111
116 comprehensive mass and energy balance, 122
149 Avalanche theory, 126
129 conventional mass-balance equation incorporating only tangibles, 122f disconnection of origins from process, 147
149 energy, 123
125 energy spectrum modeling, 133
140 law of conservation of mass and energy, 125
126 mass-balance equation incorporating tangibles and intangibles, 123f natural frequency of body parts, 141
147 rebalancing mass and energy, 122
123 simultaneous characterization of matter and energy, 130
133 tangible/intangible conundrum or yin
yang cycle, 149 sustainable development, 183
189 technology, 846 water, air, clay, and fire in scientific characterization, 116
121 Oil production and consumption history, 317f Oil refineries, 220, 515
516 Oil refining, 177
178, 177f, 178f pathways, 176
180 auxiliary emissions, 180 combustion emissions, 179 fugitive emissions, 179 process emissions, 179 storage and handling emissions, 179 pathways of, 176
180 process and various types of catalyst used, 223t processing, 229 Oil separation, fundamental considerations of, 847
848 Oil sliding angle (OSA), 574
576

Index

Oil spills, 519 Oil storage, 500
502, 511
519 contamination, 519 domed external floating roof tank, 514
515 external floating roof tank, 514 fixed-roof tank, 512
513 horizontal tank, 515 internal floating roof tank, 514 liquefied natural gas storage tank, 519 pressure tank, 515
518 tanks, 511 variable vapor pace tank, 518 Oil surplus ensues, 346 Oil tankers, 520, 522t Oil three-phase systems, 571
572 Oil trade movement, 660f Oil transportation, 391 Oil viscosity, 568 Oil water separation, 365 Oil-based coatings, 823
825 Oil-based muds (OBMs), 32
33 Oil-in-water-in-oil (O/W/O), 365
366 Oil/water separator, benefits of, 559
560, 560t Oil/water separators, types of, 558
559 coalescing oil/water separators, 559, 559f gravity oil/water separators or API separators, 558
559 Oil
water emulsions, 193 Oil
water separation, 560
587 contact angle measurement of oil drops immersed in water environment, 563f droplet size distribution for water-in-crude oil emulsion measured by NMR, 570f measurement of separation efficiency, 565f mechanism involved in nanowire copper mesh, 573f methods, 561 oil contact angles and oil sliding angles for droplet, 577f oil
water separation setup facility developed in our laboratory, 564f oil
water separation study using prewetted sand layer, 578f sands for separation of oil and water, 571f setup facility developed in our laboratory, 564f Stoke’s law configuration, 568f study using prewetted sand layer, 578f typical crude oil characteristics, 569t Oil
water
sand three-phase system, 586
587 Oily industrial wastewater, 586
587 Oily materials, 273
274 Oily process, 559
560 Onondaga reef fields, 110 OOIP. See Original oil in place (OOIP) OPEC. See Organisation of Petroleum Exporting Countries (OPEC)

903

Open circuit potential (OCP), 768 Open tridirectional zeolites, 251 OPS. See Office of Pipeline Safety (OPS) Opsco Manufacturing, 410 Optical fiber sensor (OFS), 494 Optical microscopy, 570, 583
584 Orbital shapes, 208 Ore minerals, 738t Organic acids, 227, 702 Organic body, 286 Organic compounds, 285 and functions, 286t Organic green inhibitors, 803 Organic liquids, 511 Organic mixture, 351 Organic nitrogen compounds, 312 Organic processing of metal, 848 Organic solvents, 674 Organic-based membranes, 573 Organic-rich shale basins, 421 Organisation for Economic Co-operation and Development (OECD), 64
65 Organisation of Petroleum Exporting Countries (OPEC), 24, 317
318 Original oil in place (OOIP), 406
408 Oriskany fields, 110 OSA. See Oil sliding angle (OSA) Oscillation sensor, 355 Osmium, 231 “Ouch-ouch” disease, 241
242 Outer diameter (OD), 394 Oval gasholders, 549
550 Owners and operators of storage facilities, 532
534 Ownership of types of pipelines, 550t Oxalate, 182, 673 Oxalic acid, 674 Oxidation, 741
743 Oxide minerals, 739 Oxide promoted metals, 200 Oxy-acetylene, 339 Oxygen (O), 6
7, 112, 360, 604, 643
644, 674, 707
708, 732
733 compounds, 112 contrasting and unifying features of, 288t contrasting properties of, 278
283 opposing properties of, 280t phase diagram of hydrogen, 281f similar and contrasting properties of, 282t electronegativity, 281 gas, 282 oxygen-rich-groundwaters, 741 reduction, 752 Oxynitride hydride, 200 Ozone (O3), 282 molecules, 295
296

904 P p-NC membranes. See Porous nitrocellulose membranes (p-NC membranes) PAH. See Polycyclic aromatic hydrocarbon (PAH) Parabolic solar collector, 691, 693 Parabolic solar contractor, TV, FV and RHSV of, 693f Paradox of value, 271
272 Paraffin crystallization, 365 liquid, 574
576, 581
582 Paraffinic waxes, 351
352 Parkinson disease (PD), 632 Particle, 264 Partner countries alliance, 24 Passive methods, for leak detection, 453 Passive thermography, 470
471 Pauli’s exclusion principle, 206, 211 PCB. See Printed circuit board (PCB) PD. See Parkinson disease (PD) Peas, 312 PEGDA. See Poly(ethylene glycol)diacrylate (PEGDA) Pellet-burning process, 733
736 Pentane, 364, 702 Pentium, 688 PEO. See Poly ethylene oxide (PEO) Per capita energy consumption in world, 652f Percent drag reduction (%DR), 385
386 Permeability, 437 Perovskite oxide hydride, 200 Pervaporation membranes for methanol
methyl acetate separation, 160t PES. See Philadelphia Energy Solutions (PES) Petrochemicals, 191
192, 194 growth in, 192f plants, 515
516 products, 191 Petroleum, 30, 841 in big picture, 842
844 illogical premises, 843f scientific and social theories invoked phenomenal premises, 842f commodities, 842 comparison between water and, 275
278, 277t, 279t cracking process, 224 energy in 2020, 41
50, 47f coal reserve, 42t coal resources in United States, 42f energy consumption, 44f global coal production, 43f gold prices in Russian ruble, 49f gold prices in US dollar, 49f ether, 577 green, 69
79

Index

China has surpassed 2020 solar PV target Image, 71f comparison of energy sources, 78f copper reserves, 74t Denmark is expected to world leader, 71f energy growth of energy sources, 76f fast-tracking renewables, 76
79 fuel shares of primary energy and contributions to growth, 78t global shares of selected minerals, 72t growth in renewables, 70f new world order, 50
68 battery electric vehicles worldwide, 57f EIA, 68f electric vehicle manufacturing, 56f fractions of different energy sources on global consumption, 64f fuel shares of primary energy and contributions to growth, 65t global energy consumption, 63f global power generation, 65f, 66f growth in oil demand, 58f public perception toward energy sources, 68f, 69f supply and demand in 2020, 60f world fossil fuel consumption, 62f oil and gas, 93
103 operations, 497 pipelines, 320 processing and separation, 3
17, 8f crude oil inherently complex thousands of components, 3f fluctuations in API gravity in US refineries, 15f important process developments in petroleum refining, 10t molecular structure of refined petroleum products, 5f optical microstructures of crude oil tube two different magnifications, 4f per calendar day production for refineries in various regions, 13f poison by selective catalyst, 11t poison by structure, 11t simplified refinery flow diagram, 8f steam cracking yields obtained several heavy feedstocks, 9t US atmospheric crude distillation capacity, 12f US refinery inputs, capacity, and utilization, 14f products, 191, 285, 319
320, 323f refining, 177, 183
185, 188t, 220
222 important process developments in, 10t reservoirs, 193
194, 219, 636 resources, 3, 193
194, 841
842 role of oil and gas, 79
93 science of, 271
275 world energy, 39
41, 40f

Index

Petroleum fluids, 1, 220, 497
511, 499f, 500f annual change history in various geographical areas, 499f conventional classification of, 636
642 current world storage capacity, 502t existence of eutectic point, 637f gas storage, 523
551 history of “open access” to storage capacity, 523
525, 534
535 owners and operators of storage facilities, 532
534 storage measures, 526
532 underground natural gas storage data, 525, 535
539 monthly history of liquid fuel consumption, 498f natural gas storage, 505
511 schematic of natural gas storage sites, 507f storage and withdrawal of natural gas during year, 506f underground storage and withdrawal in United States, 507f oil storage, 511
519 contamination, 519 domed external floating roof tank, 514
515 external floating roof tank, 514 fixed-roof tank, 512
513 horizontal tank, 515 internal floating roof tank, 514 liquefied natural gas storage tank, 519 pressure tank, 515
518 variable vapor pace tank, 518 storage of, 847 tankers for oil storage, 519
523 US strategic petroleum reserve, 502
505 crude oil inventory by site, 503 current authorized storage capacity, 503
504 drawdown capability, 504 highest inventory, 503 past exchanges, 504
505 past sales, 504 previous inventory milestones, 503 world liquid fuel balance in recent years, 498f world oil demand and supply, 501t PF. See Product function (PF) PGMs. See Platinum group metals (PGMs) Pharmaceutical industries, 245
246 Phase difference, 460 Phenol, 226 Philadelphia Energy Solutions (PES), 12 Phillipsite, 249 Phosphate, 287
290 Phosphenol-pyruvate carboxylase, 269 Phospholipids, 683 Phosphorous, 338, 684

905

Photoconductive effect, 608 Photoelectric effect, 606 Photoelectrochemical effect, 608 Photoelectrons, 606 Photoemission from atoms, molecules, and solids, 609
610 Photons, 292
293, 605
608 Photophobia, 671
672 Photosynthesis, 231
232, 269, 631 Photosynthesizing organisms, 287 Photosynthetic cycle, 269 Photovoltaic (PV), 694 effect, 608 module, 694 solar panel, 694 Physical separation process, 192 Phytochelatin-based sequestration, 231
232 PID. See Proportional-integral-derivative (PID) PIGs. See Pipeline inspection gauges (PIGs) Pipe viscometer, 354 Pipeline capacity, 549
551 gasholders, 549
550 global storage capacity, 550
551, 551f independent storage service providers, 550, 550t Pipeline designs advances in, 399, 846
847 sensory technologies, 442
488 carbon capture, 404
410 guideline for pipeline leakage detection method selection, 490
492 guidelines for method selection, 492t HDS, 399 performance comparison of leak detection technologies, 488
490 research gaps and open issues, 492
496 satellites and pipeline safety, 400
404 airbus intelligence, 403 China Siwei, 404 CORONA program, 400 GeoEye, 402 ImageSat international, 403
404 Landsat, 400 Maxar, 402
403 Meteosat, 402 MODIS, 400 Planet’s RapidEye, 403 Sentinel, 400
401 spot image, 403 sustainability in retaining natural traits of matter, 847f sustainability of CO2 sequestration and storage, 411
442 Pipeline inspection gauges (PIGs), 396
397

906 Pipelines, 17, 761, 842 coatings, 718
729 environmental stresses and influence on coating materials, 719t patents and invention of toxic additives, 721t structure of PVC molecules, 719f cost calculations, 431
432 diameter calculations, 430
431, 430t distribution of pipeline products, 325f failure, 446, 447f faults, 458 leakage detection guideline for pipeline leakage detection method selection, 490
492 systems, 470 lubrication, 387 material, 320 monitoring system, 394
398 oil and gas pipeline types, 394
398 monitoring, 399 network, 846 systems, 20, 319, 508, 549, 644, 665
666, 778
779 under modeling, 831f PISC. See Postinjection site care (PISC) Pitting corrosion, 396, 782
790 actively growing pit in iron, 787f Pitting process, 782
783 Pitting resistance equivalent number (PREN), 789 Planck’s constant, 123
124, 606 Planck’s Law, 613 Planet’s Rapid Eye, 403 Plantation Pipeline, 341 Plant growth in solar aquarium, 34 Plant
water relationships, 231
232 Plasmas, 206, 303 Plastic, 191, 394 crystalline, 637
638 culture, 844
845 deformation, 450 Plasticizers, 720 Platinum, 116, 229
231 compounds, 229
230 Platinum group metals (PGMs), 230 PLC. See Programmable logic controller (PLC) Ple´iades constellation, 403 Ple´iades-HR 1A, 403 Ple´iades-HR 1B, 403 Ple´iadesNeo, 403 Polar mesospheric clouds, 300
301 Polar water molecule, 581
582 Poly ethylene oxide (PEO), 387 Poly(ethylene glycol)diacrylate (PEGDA), 562 Polyalpha-olefin, 385
386

Index

Polycyclic aromatic hydrocarbon (PAH), 351
352 Polyhydroxy compound, 735 Polymer surfaces, 194
195 Polymeric compounds, 381 Polymerization, 562, 719 Polymers, 286, 383, 803 Polyoxyethylene, 372 Polyurethane, 360
361 Polyvinyl chloride (PVC), 450
451, 718 Pore space acquisition, 435, 442 Porous nitrocellulose membranes (p-NC membranes), 573 Porous polymers, 574 Post-COVID-19 crisis, 847 Postinjection site care (PISC), 436, 442 Potassium, 200 formate, 704 iodide, 798
799 Potential energy for interaction between two gaseous hydrogen atoms, plot of, 205f Pour point depressants (PPDs), 357, 380
382 chemical structure of ethylene-vinyl acetate copolymer, 382f molecule, 381 Power reflection ratio, 458
460 PPA. See Pressure point analysis detection (PPA) PPDs. See Pour point depressants (PPDs) Pragmatic approach, 208 PREN. See Pitting resistance equivalent number (PREN) Pressure drop, 431 Pressure gauges, 686f Pressure point analysis detection (PPA), 483 Pressure tank, 512, 515
518 cylindrical pressure vessel, 517 lifting and handling of a pressure vessel, 517 pressure vessel heads, 517
518, 518f spherical pressure vessel, 516, 516f Pressure-Volume Temperature property (PVT property), 531 PRFE therapy. See Pulsed radio frequency energy therapy (PRFE therapy) Primary hazardous/solid wastes, 226 Primary recovery techniques, 416 Primary wasters from oil refinery, 227t Primary wastes from oil refinery, 179t Printed circuit board (PCB), 473
474 Process emissions, 179 Processing chemicals and natural gas relationship, 673
676 fundamentals of, 844, 845f Product function (PF), 485

Index

Production chemical compounds, 193 solids, 193 Programmable logic controller (PLC), 392
393 Promoter materials, 200 Propane, 11, 94, 515
516, 644, 658
659, 702 Propene, 8
9 Proportional-integral-derivative (PID), 484
485 Propylene, 226 Proteins, 284, 683 Protocols, 846 Proton
proton repulsive interactions, 204 Pseudomonas aeruginosa, 796 Psoralen plus ultraviolet A therapy (PUVA therapy), 632 Psycrophiles, reaction mechanisms of, 683 Psycrophilic bacteria, 682
683 Puddling process, 729 Pulse echo methodology, 458
464 accelerometers, 463
464 acoustic reflectometry, 461 stochastic successive linear estimator, 462
463 transient wave blockage interaction and blockage detection, 461
462 Pulsed eddy current techniques, 775 Pulsed radio frequency energy therapy (PRFE therapy), 632 Pump power requirements, calculation of, 426
428 Pure water, droplet size distributions after atomization of, 593f Purge gas, 197 Purging process, 197 Purified water, 121 PUVA therapy. See Psoralen plus ultraviolet A therapy (PUVA therapy) PV. See Photovoltaic (PV) PVC. See Polyvinyl chloride (PVC) “Pyramidal” model, 231
232 Pyrite, 739
740

Q Quantum, 211 dots, 209
210, 245 mechanics, 208 Quark-gluon plasma, 619f Quasi-underwater superoleophobicity, 574

R Radial basis kernel function (RBF), 444 Radiation, 266, 296, 300, 631 Radiation therapy (RT), 633 Radioactive highly unstable isotopes, 312 Radiographic inspection, 342 Radiotherapy (RT), 633

907

Radius (R), 518 Rain water, 278 Raman scattering, 464, 466
467 Raman spectroscopy, 637 Raoult’s law, 634 RapidEye, 403 Raw materials, 73
74 Rayleigh scattering, 464 Rays, 293
294, 312 RBF. See Radial basis kernel function (RBF) RD. See Reactive distillation (RD) Reaction, 266 mechanisms, 200
201 of barophiles and psycrophiles, 683 Reactive distillation (RD), 157, 553 Reactive dividing-wall column, 163f Recommended practices (RPs), 509 Rectisol acid gas removal technology, 408 Recycled gas, 197 Reduction process, 278
281 reactions, 269 Refined level set grid method (RLSG), 599
600 Refined oil, 511 Refined products pipeline systems, 320 Refinery Capacity Report, 12
13, 16 Refining process, 175
183, 220
228, 707
708, 712
713 in 19th century, 111f catalysts and materials used to produce catalysts base metals and compounds, 229t chemicals used during, 111
116 arsenic, 112
114 cadmium, 114 chromium, 114 copper, 115 iron, 115
116 layout of high-conversion oil refinery, 113f lead, 114 manganese, 116 mercury, 115 nickel, 115 platinum, 116 properties of petroleum refinery catalysts, 113t silver, 114 tin, 115 zinc, 116 chemicals used in refining, 228t details of oil refining process and various types of catalyst used, 223t emissions from refinery, 227t industry, 6
7 major steps involved in refining process, 221f pathway followed by refining process, 221f pathways of crude oil formation, 176

908

Index

Refining process (Continued) pathways of gas processing, 180
183 pathways of oil refining, 176
180 pictorial view of fractional column, 222f pollution prevention options for different activities in material transfer and storages, 228t primary wasters from oil refinery, 227t refinery distillation column and major products, 175f various processes and products in oil refining process, 225t Reflux process, 812
814 Reflux ratio (RR), 159 Reforming, 186
189, 258
259 coprocessing of benzene in naphtha isomerization, 259f elementary reactions occurring simultaneously in reforming of naphtha, 258f Refraction of light, 605 Regional prices, 544
545, 544f Reheating process, 729 Relative humidity (RH), 754
755 Reliability, 492
493 Remote terminal units (RTU), 392
393 Remotely operated vehicles (ROVs), 476 Renewable energy, 79, 200, 843 “Renewable” electricity, 201 Representative regional prices, 544f Research and Special Programs Administration (RSPA), 765 Residuals, 487 stresses, 761 Resins (R), 351
352 Resistance temperature detectors (RTDs), 470
471 Respiration, 231
232 Reversible processes, 123
124 Reversible reaction, 196
197 Reynolds number (Re), 430, 433 RH. See Relative humidity (RH) Ribulose 1,5-bisphosphate (RuBP), 269 Richardson equation, 207 River erosion, 400, 410 RLSG. See Refined level set grid method (RLSG) Robotics, 476 Rockies Express pipeline, 327
328 Roof manholes, 513 ROVs. See Remotely operated vehicles (ROVs) Royal Society of Canada, The, 236 Royal Vopak, 24 RPs. See Recommended practices (RPs) RR. See Reflux ratio (RR) RSPA. See Research and Special Programs Administration (RSPA) RT. See Radiation therapy (RT); Radiotherapy (RT)

RTDs. See Resistance temperature detectors (RTDs) RTU. See Remote terminal units (RTU) RuBP. See Ribulose 1,5-bisphosphate (RuBP) Russian energy sector, 97
98 Rutherford’s atomic model, 625f

S SAD. See Seasonal affective disorder (SAD) Safety risks, 320
326 Salinity, 569 Saltwater, 707 Sand, 574 jets and drains, 587
591 determination of jet boundary via thermocouples, 589f evaporative liquid nitrogen jet in air, 588f horizontal separator fitted with sand jets, 587f solids concentration on spray jet evaporation, 589f for separation of oil and water, 571f Satellite technology, 846 Saturated CO2, 768
769 Saturates (S), 351 Savitzky-Golay signal filtering algorithm, 496 SAW Engineering, 410 SBU. See Secondary building unit (SBU) SCADA. See Supervisory control and data acquisition (SCADA) SCADA system, simplified schematic of, 393f Scanning electron microscopy (SEM), 712 images, 574, 769 photomicrograph of SRB, 825f Scattering, 464 SCC. See Stress corrosion cracking (SCC) Science of corrosion, 736
754 distribution of abundant elements in earth crust, 737f natural protection, 743
754 ore minerals and their natural states, 738t sulfides and sulfosalts, 740t of lightening, 291
307 conceptual model of electrical structure in mature, mid-latitude convection, 302f depiction of thermonuclear reactions, 293f spectrum of greenhouse radiation measured at surface, 300f sun composition, 298t temperature profile of atmospheric layer, 294f time-height plot of kinematic, electrical, and cloud microphysical parameters, 305f wavelengths of known waves, 299t wavelengths of various visible colors, 298t World map of frequency of lightening, 307f

Index

SCL process, 197 SDH. See Synchronous digital hierarchy (SDH) SDI. See Segregation drive index (SDI) Sea floor sediment, 643 Seasonal affective disorder (SAD), 631 Second SMR reactor, 201
202 Secondary building unit (SBU), 232
234 Sedimentation, 321 Segregation drive index (SDI), 531 Seismicity, 400, 410 Selenium, 229
230, 244 Selenocysteine, 244 Selenomethionine, 244 Selenoproteins, 244 Selexol process, 201
202 SEM. See Scanning electron microscopy (SEM) Semi-automated detection, 447 Sensing, 468 Sensitivity, 492
493 Sensor hose system for pipeline leakage detection, 470f Sensory technologies, advances in, 442
488 dynamic modeling, 486 emerging methods, 473
481 exterior-based leak detection methods, 450
458 fiber optic method, 464
469 infrared thermography, 469
473 interior/computational methods, 481
486 pulse echo methodology, 458
464 state estimators/observers method, 486
488 vapor sampling method, 469 Sentinel, 400
401 Sentinel-1, 400
401 Sentinel-2, 400
401 Sentinel-3, 400
401 Separate phase movement (SPM), 164 Separation of oil and gas additives and functions, 229
239 benefits of natural chemicals, 240
244 demand for plastic resin in various countries, 193f fundamental of surface chemistry, 194
220 fundamentals of, 844
846 growth in petrochemicals, 192f nitrogen cycle, 307
316 restoring science of nature, 263
290 carbon
oxygen duality, 284
290 comparison between water and petroleum, 275
278 contrasting properties of hydrogen and oxygen, 278
283 nature of material resources, 270
271 redefining force and energy, 264
268 science of water and petroleum, 271
275, 272f, 274f

909

transition of matter from sun to earth, 268
270 science of lightening, 291
307 science of nanoscale, 244
249 separation and refining process, 220
228 typical wastewater composition from petrochemical and gas production, 194t zeolite as refining catalyst, 249
262 Separation process, 175
176, 220
228, 553, 844 details of oil refining process and various types of catalyst used, 223t pictorial view of fractional column, 222f Sewage water, 34 Shale, 529 gas resources, 421 Shape selectivity, 252 Shell Oil’s Denver Unit, 407 SHIP. See Single heated electrically insulated pipeline (SHIP) SI. See International System of units (SI) Siderite (FeCO3), 199
200 Signal transmission, 468 Silica, 224
226 nanoparticles, 358
360 Silicic acid, 287
290 Silicon, 70
71, 244, 338 Silicon dioxide, 574 Silver, 114 Simulation scenarios by sensitivity type, 439t Simultaneous characterization of matter and energy, 130
133 results from carbon combustion, 133f sustainable pathway for material substance in environment, 132f synthetic nonbiomass, 132f Single crystal X-ray diffraction analysis, 232
234 Single heated electrically insulated pipeline (SHIP), 380 Single injector/producer well pairing, 442 Single Shot MultiBox Detector (SSD), 477 Single-crystalline, 83
84 Single-molecule magnet (SMM), 232 Single-stage hydrocracking process, 260f, 261 Single-walled carbon nanotube composite coatings, 562 Singlet oxygen, 282 Sludge, 519 “Small pore” zeolites, 251 SmartBall, 455
456 SMM. See Single-molecule magnet (SMM) SMR reactors. See Steam methane reforming reactors (SMR reactors) SMYS. See Specified minimum yield strength (SMYS) Sodium acrylate, 736 Sodium atoms, 616 Sodium chloride, 361

910 Sodium hexametaphosphate, 390 Sodium nitrite, 702
703 Software-based methods, 447
448 Soil contamination, 519 disruption, 321 moisture, 771 Solar energy, 35, 74, 83
84 Solar heat transfer fluid, 694
695, 695t Solar irradiation for hydrate, 691
698 experimental procedure, 695 experimental setup and procedures, 692
694 construction solar collector assembly, 693f experimental solar trough, 692f TV, FV and RHSV of parabolic solar contractor, 693f results, 695
698 experimental data for once-through process, 697t fluid characteristics and recorded temperature of fluid in different months, 696t temperature profile for absorber clean canola oil and waste vegetable oil, 697f solar heat transfer fluid, 694
695 solar pump and photovoltaic solar panel, 694 Solar parabolic solar unit, 696 Solar pump, 694, 694f, 698 Solar PV module, 695f Solar radiation spectrum, 617f Solar receiver in focal line of parabolic solar surface, 694f Sol
gel method, 562 Solid wastes, 226 Solid(s), 268, 355, 554 acids, 250 concentration on spray jet evaporation, 589f entity, 212 particles, 591 photoemission from, 609
610 surface, 565
566, 571
572 three-phase systems, 571
572 Solutions, 676
698 experimental apparatus, 684
690 bacteria counting, 687
689 cylinder and hydraulic jack, 687f cylinder assembly, 687f cylinder for experiment, 684f experimental procedure, 690 main pressure gauges, 686f methane tank assembly, 686f preparation of samples, 685
687 window end of cylinder, 685f first approach, 676
681 ethylene glycol, 676
680

Index

monoethanolamine, 681 second approach, 682
690 bacteria growth and survival requirements, 684 hydrate formation prevention through biological means, 682
683 reaction mechanisms of barophiles and psycrophiles, 683 solar irradiation for hydrate, 691
698 Sound pressure level (SPL), 453 SPAIR spectra on Pb electrode after bubbling CO2, 239f, 240f Specified minimum yield strength (SMYS), 344, 771 Spectral scanners, 473, 475t Spectrum of greenhouse radiation measured at surface, 300f Speed of propagation, 453 Spills, 322 Spiral-guided gasholders, 549 SPL. See Sound pressure level (SPL) SPM. See Separate phase movement (SPM) Sports utility vehicles (SUVs), 347 Spot image, 403 SPR. See Strategic Petroleum Reserve (SPR) Spray combustion, 592 process, 592f Sprites, 300
301 SRB. See Sulfate-reducing bacteria (SRB) SRM. See Surrogate reservoir model (SRM) SS. See Stainless steels (SS) SSD. See Single Shot MultiBox Detector (SSD) Stainless steels (SS), 563
564, 718, 750, 790
791, 796 Startec, 410 State estimators/observers method, 486
488 Steam engines, 337 methane reforming reactions, 202
203 steam
methane
reforming reaction, 156 treatment, 256 Steam methane reforming reactors (SMR reactors), 201
202 Steel, 191 steel-making process, 732 Stephen Boltzmann law, 137 Stephen’s constant, 137 Stilbite, 249 Stochastic successive linear estimator, 462
463 Stoke’s law, 558 configuration, 568f Stokes components, 465
466 Storage, 21
25 capacity additions, 545
549 different types of terminals, 22
24 global players on storage terminals market, 24
25

Index

and handling emissions, 179 history of “open access” to storage capacity, 523
525 measures, 526
532, 535 of petroleum fluids, 847 Storms, 321 Strategic Petroleum Reserve (SPR), 502
503 Stratigraphic trapping, 415 Stratosphere, 268 Stratus clouds, 303 Stress corrosion, 761
780 conditions contribute to stress-corrosion cracking, 771
772 management of stress-corrosion cracking threat, 778
780 stress-corrosion cracking detection, 772
778 stress-corrosion cracking in buried pipelines, 766t Stress corrosion cracking (SCC), 754 in buried pipelines, 766t conditions contribute to stress-corrosion cracking, 771
772 detection, 772
778 management of stress-corrosion cracking threat, 778
780 Stress wave, 450 Stress
strain relationship for various fluids, 353f Subatomic particles, 207
208, 215
216 Subatomic physics, 215 Sublimation, 106
107 Subsurface maintenance, 434 Sulfate-reducing bacteria (SRB), 398, 795 Sulfides, 740t minerals, 705
706, 740
741 Sulfite oxidases, 243 Sulfosalts, 740t Sulfur (S), 6
7, 338, 360, 795 compounds, 4, 111 diesel, 326 sulfur-containing compounds, 787
788 Sulfur dioxide (SO2), 519 Sulfuric acid (H2SO4), 112, 707
708 aerosols, 226 Sulphur, 684 Superhydrophilic material, 571
572 Superlubricity, 214
215 Superoleophobic materials, 571
572 Superoleophobicity, 565 Supervisory control and data acquisition (SCADA), 322, 488
489 Support vector machine (SVM), 458, 463
464 Support vector regression (SVR), 444 Surface chemistry, fundamental of, 194
220 connection between subatomic and bulk properties, 207
213

911

electronic energy levels depending on number of bound atoms, 209f electrons in three-dimensional bulk solid, 212f size dependence of energy gap for colloidal CdSe quantum dots with diameter, 213f correct formulation, 213
220, 214f, 216f, 217f, 218f, 219f Haber process, 195
203 Langmuir adsorption, 203
207 Surface diffusion, 220 Surface maintenance, 434 Surface reaction, 200 Surface rheology, 367 Surface Search, 410 Surface tension, 595 Surfactants, 383 Surrogate reservoir model (SRM), 423
424 linking surrogate reservoir models to technoeconomic analysis, 428
429 Sustainability, 192, 273, 841 of CO2 sequestration and storage, 411
442 carbon backbone, 411
420 carbon capture and storage for enhanced oil recovery, 420
423 technoeconomic model, 423
442 in retaining natural traits of matter, 847f status of current technologies, 25
38 Sustainable development, 30, 183
189 catalytic cracking, 185 isomerization, 186 petroleum refining and conventional catalysts, 183
185 reforming, 186
189 scenario, 24 Sustainable petroleum technology, 83
84 Sustainable process, 28f, 848 Sustainable solutions, 646 Sustainable technology, 27
28, 191, 419
420 SUVs. See Sports utility vehicles (SUVs) SVM. See Support vector machine (SVM) SVR. See Support vector regression (SVR) Synchronous digital hierarchy (SDH), 393 Synthetic catalysts, 224 Synthetic chemicals, problems with, 670
676 pathways, 216f, 673 processing chemicals and natural gas relationship, 673
676 diethanol amine, 675 ethylene glycol, 674 methanol, 674 monoethanolamine, 674
675 TEA, 675
676 Synthetic organic fluids, 691 Synthetic polymers, 181
182

912

Index

T TAME. See Tertiary amyl methyl ether (TAME) TAN. See Total acid number (TAN) Tangible mass, 122 Tangible/intangible conundrum, 149 Tanker fleet, 521t for oil storage, 519
523 breakdown of various classifications of oil tankers, 522t tanker fleet, 521t tanker types and capacities, 520f types and capacities, 520f TAPS. See Trans Alaska Pipeline System (TAPS) Technoeconomic model, 423
442 calculation of compressor and pump power requirements, 426
428 categorization of simulation scenarios by sensitivity type, 439t comparison of results with prior research, 443t contribution of cost components to total unit technical cost, 441f cost of CH4/CO2 mixture separation, 435
436 detailed assumptions for scenario simulation, 438t framework, 423f injection characterization, 432
434 pumping cost calculations, 434 wellhead pressure calculations, 432
434 injection costs, 434
435 inputs, and outputs, 425t pipeline cost calculations, 431
432 PISC, 436 production characterization, 435 representative CO2 capture cost estimates, 424t structure, 429
431 technoeconomic analysis scenarios, 440f unit cost analysis, 436
441 TEG. See Triethylene glycol (TEG) TEL. See Tetraethyl lead (TEL) Temperature, 355, 469
470 profile for absorber clean canola oil and waste vegetable oil, 697f variation, 495
496 Tensile stress, 766
767 Terminal logistics, 325 Terphenyls, 691 Tertiary amine, 675 Tertiary amyl methyl ether (TAME), 228t Tetraethyl lead (TEL), 228t Tetramethyl lead (TML), 228t TFA. See Titas Franchise Area (TFA) Thermal cameras, 470
471 Thermal capacity, 604

Thermal cracking process, 223t units, 15 Thermal fluid, 694
695, 698 Thermal storage materials, 691
692 Thermal voltage, 612 Thermal-hydraulic testing process, 18
19 Thermally coupled reactive distillation with pervaporation, 160f Thermionic emission, 206 Thermions, 206 Thermocouples, 470
471 Thermodynamic inhibitors, 661
662, 663t, 667 Thermodynamic solid-liquid equilibrium model, 463 Thermodynamic wax, 381 Thermoelectrical plants, 367 Thermogram(s), 470, 570 Thermography, 470
471 Thermosphere, 268, 301 THIs. See Threshold hydrate inhibitors (THIs) Three-dimensional bulk solid, electrons in, 212f Three-dimensional seismic imaging (3D seismic imaging), 110 3-carbon compound, 269 Threshold hydrate inhibitors (THIs), 667
668 Threshold stress, 767 Thromobocytes, 240
241 Thundersnow, 304
305 Time function, 216
217 Time of flight diffraction (TOFD), 776 Time of flight diffraction and imaging (ToFDI), 776 Time-frequency technique, 484 Timely pipeline leak detection, 442
444, 488
489 Tin, 115, 244 TiO2 coated stainless steel mesh, 563
564 TiO2 nanoparticles, 562 Titanic tumult, 267 Titanium, 796
797 corrosion process, 796
797 Titas Franchise Area (TFA), 474 TML. See Tetramethyl lead (TML) TMS. See Transcranial magnetic stimulation (TMS) TOFD. See Time of flight diffraction (TOFD) ToFDI. See Time of flight diffraction and imaging (ToFDI) Tolman length, 595 Toluene, 224
226, 360 Torques, 264 Total acid number (TAN), 357 Total fixed nitrogen, 314 Toxic catalysts, 519 Toxic chemicals, 227, 720
721 Trace elements, 222, 244 Trans Alaska Pipeline System (TAPS), 345

Index

Trans-Mediterranean natural gas pipeline, 328 Transcranial magnetic stimulation (TMS), 632 Transient wave blockage interaction, 461
462 Transient-based leak detection approaches, 486 Transition metals, 220 Transition of matter from sun to earth, 268
270 Transmission of gamma-rays, 463 Transportation analysis, 18
19 flow assurance strategies, 19 module, 430 of oil and gas, 317
328, 846 1850
75
pipelines, 332
337, 333f 1876
1900, 337
338, 338t 1901
25, 339
341 1926
50, 341
343, 344t 1951
75, 343
345 1975
2000, 345
347 2000-present, 347
350 compressor stations, 321 crude oil composition and their properties, 352t crude oil pipeline system overview, 319f digital networking technologies, 392
394 Eastern Siberia
Pacific Ocean pipeline, 327 electrically heated subsea pipelines, 379
380, 380f eminent domain, 321 environmental health and safety risks, 320
326 erosion and sedimentation, 321 explosions, 322
326 flow rate vs. diameter, 353f gas pipeline systems, 328
331 heavy crude oil pipelines, 350
392, 351t historical perspective, 331
350 Kazakhstan
China pipeline, 327 Keystone XL, 327 land use and forest fragmentation, 321 large pipeline projects, 326
328 oil and gas pipeline types, 394
398 oil production and consumption history, 317f pipeline monitoring system, 394
398 pour point depressants, 380
382, 381f recent history of US and China import scenario, 318f reducing friction, 382
387 Rockies Express pipeline, 327
328 simplified schematic of SCADA system, 393f spills and leaks, 322 stress
strain relationship for various fluids, 353f Trans-Mediterranean natural gas pipeline, 328 viscosity reduction, 361
379 West-East pipeline project, 326 Wloclawek gas compressor station, 326 optimization strategies, 20
21

913

prevention strategies, 19 remediation strategies, 19 sampling, 18 scenario modeling, 19 Trenton limestone, 110 Trenton-Black River gas, 110 Tri-alcohol, 675 Trichloromethane, 111 Triethanolamine (TEA), 181
182, 675
676 Triethylene glycol (TEG), 181
182, 361, 667 1,2,4-trimethylbenzene, 226 Trivalent chromium, 242 Turbulent flow system, 837 Two-stage hydrocracking process, 260f, 261

U UIC. See Underground injection control (UIC) ULCC. See Ultra-large crude carrier (ULCC) Ultra-large crude carrier (ULCC), 520
521 Ultrasonic gas leak detectors, 454
455 Ultrasonic methods, 509 Ultrasonic transducer (UT), 396
397 Ultrasonic waves, 777 Ultrasound, 157
158, 453 Ultrasound-assisted enzymatic reactive distillation (US-ERD), 157
158, 158f Ultraviolet (UV) irradiation, 562 radiation, 606 UV-spectroscopy, 798
799 Underground injection control (UIC), 441
442 Uniform corrosion, 396 Unit cost analysis, 436
441 Unit Technical Cost (UTC), 436
437 United States Geological Survey (USGS), 39, 321 United States Shipping Board (USSB), 521
522 Unsustainable technology, 28f US petroleum, 503
504 US strategic petroleum reserve, 502
505 crude oil inventory by site, 503 current authorized storage capacity, 503
504 drawdown capability, 504 highest inventory, 503 past exchanges, 504
505 past sales, 504 previous inventory milestones, 503 US-ERD. See Ultrasound-assisted enzymatic reactive distillation (US-ERD) USGS. See United States Geological Survey (USGS) USSB. See United States Shipping Board (USSB) UT. See Ultrasonic transducer (UT) UTC. See Unit Technical Cost (UTC) UVB phototherapy, 632

914

Index

V Vacuum distillation, 150
174, 192 conventional phase diagram, 151f improving distillation, 151
164 4-component basic configuration, 152f 6-component basic configuration, 152f Brugma configuration, 152f derived HMP configuration, 152f DWC of Brugma configuration, 152f enumeration of HMP configurations, 153t heat and mass integrated configuration, 152f manipulated variables of optimization, 159f simple adiabatic column with total condenser, 161f US-ERD process, 158f optimization, 164
174 identification of “d” submixtures in matrix, 166f matrix for five-component feed mixture, 166f matrix for three-component feed mixture, 171f steps, 165
173 Valence electron configurations, 204 Valence shell, 204 van der Waal’s forces, 213
214 Vanadium, 11, 226, 244 Vane technology, 555 Vapor(s), 511 sampling method, 469, 475t VAPOR sensing cables, 446 vapor/liquid separation, 591
600 aerosols, 592
597 direct numerical simulation of primary atomization, 597
598 length and time scales, 598 motion of phase interface, 598
600 Vapour
liquid equilibrium (VLE), 634
642 conventional classification of petroleum fluids, 636
642 difference between Henry’s law and Raoult’s law, 635t Variable vapor pace tank, 518 VCAP. See Vinylcaprolactam (VCAP) VCM. See Vinyl chloride monomer (VCM) Velocity distribution, 591 Vertical separator, 556 Very large crude carriers (VLCCs), 521 VESD. See Volume equivalent spherical diameter (VESD) Vibration analysis, 458 accelerometers mounted on pipe surface, 460f frequency response at three accelerometer location, 460f Vinyl chloride monomer (VCM), 719 Vinylcaprolactam (VCAP), 668
669 Vinylmethylacetamide (VIMA), 668
669

Viscosity, 418
419, 433
434, 596f Viscosity implication, 365 Viscosity reduction, 361
379 dilution of heavy and extra-heavy crude oils, 361
365 formation of heavy and extra-heavy crude oil-inwater, 365
374, 365f, 368f emulsions found in petroleum production and transport, 366f miscroscopic observation of droplet size evolution, 370f heating heavy and extra-heavy crude oil and heated pipelines, 376
379, 377f kerosene on crude oil viscosity, 378f viscosity behavior for W/O emulsions, 377f heavy oil emulsions for transport in cold environments, 375
376 Viscous fluids, 371 Visual/biological leak detection methods, 474
481 Viterbi decoding algorithm, 456 VLCCs. See Very large crude carriers (VLCCs) VLE. See Vapour
liquid equilibrium (VLE) Volatile fuels, 519 Volatile oils. See Essential oils Volatile organic compounds, 321 Volta potential, 759 Volta potential difference. See Volta potential Volume equivalent spherical diameter (VESD), 580

W W/O. See Water-in-oil (W/O) Wasson Field Denver Unit, 406
407 Waste management, challenges in, 32
33 breakdown of no-flaring method, 34f Waste vegetable oil, temperature profile for absorber clean canola oil and, 697f Wastewater, 193, 559 Water (H2O), 4, 17, 46, 155
156, 273, 554 absorption, 574 comparison between petroleum and, 275
278, 277t, 279t droplets, 555
556, 561 film, 566 flux, 577
579, 584
585 molecules, 576
577 part of, 307
316 quality, 569 science of, 271
275 in scientific characterization, 116
121, 120f separator, 558f solution, 387 splitting, 201 three-phase systems, 571
572

Index

turbulence, 559 water-soluble polymers, 668
669 water
gas reaction, 156 Water distribution networks (WDNs), 489
491 Water drive index (WDI), 531 Water-based muds (WBMs), 32
33 Water-in-oil (W/O), 356
357 Water-in-oil emulsions, 569 Water
diamond paradox, 271
272 Water
gas shift reactor (WGS reactor), 201
202 Water
gas-shift reaction, 156 Water
oil emulsion, 560 Wavelength of known waves, 299t of sound, 453 Waves, 67
68 Waxes, 352 crystal morphology, 381 WBMs. See Water-based muds (WBMs) WDI. See Water drive index (WDI) WDNs. See Water distribution networks (WDNs) WEPP. See West-East Gas Pipeline Project (WEPP) West Texas Intermediate (WTI), 15, 90 West-East Gas Pipeline Project (WEPP), 326 West-East pipeline project, 326 Wet corrosion, 759
761 corrosion potential for various metals, 758t Weyburn CO2 Miscible FloodProject, 404 WGS reactor. See Water
gas shift reactor (WGS reactor) WHO. See World Health Organization (WHO) Wind energy, 35, 84 Wind turbine tower (WTT), 480
481 Wireless sensor networks (WSNs), 493 Wloclawek gas compressor station, 326 Wolf Midstream, 410 Wood, 582
583 sheet, 581
582 World Energy Outlook report, 58
59 World Health Organization (WHO), 121 World liquid fuel balance in recent years, 498f

915

World oil demand and supply, 501t WorldView-3 (WV 3), 402
403 WSNs. See Wireless sensor networks (WSNs) WTI. See West Texas Intermediate (WTI) WTT. See Wind turbine tower (WTT) Wu¨stite (Fe1-xO), 199
200 WV 3. See WorldView-3 (WV 3)

X X-ray microtomography, 775
776 Xanthine, 243 Xylene, 224
226

Y Yin
Yang cycle, 149 in colloquial and scientific terms, 134, 135t representation of matter and energy, 134, 135f Young
Dupre´ equation, 565

Z Zeolite(s), 224
226, 579, 846 as refining catalyst, 249
262 chemical composition of zeolites and possibilities for control, 250f FCC, 255
258 gasoline pool, 252
253 hydrocracking, 259
262 isobutane
butene alkylation, 254
255 linear paraffin isomerization, 253
254 reforming, 258
259 schematic of shape selectivity for formation of pxylene in toluene disproportionation, 253f Zeolitic nanoparticle-coated ceramic membranes, 219
220 Zero waste, 841 condition, 124 Zero-valent iron (ZVI), 219
220 Zinc (Zn), 70
71, 116, 244, 752 metal, 749 ZVI. See Zero-valent iron (ZVI)