Chemistry for Sustainable Technologies

A Foundation

Neil Winterton

• Publisher: Royal Society of Chemistry
• Year: 2021
• eBook ISBN: 9781788019330
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Environmental Science
• Index: Technology & Engineering

Following the success of the first edition, this fully updated and revised book continues to provide an interdisciplinary introduction to sustainability issues in the context of chemistry and chemical technology. Its prime objective is to equip young chemists (and others) to more fully to appreciate, defend and promote the role that chemistry and its practitioners play in moving towards a society better able to control, manage and ameliorate its impact on the ecosphere. To do this, it is necessary to set the ideas, concepts, achievements and challenges of chemistry and its application in the context of its environmental impact, past, present and future, and of the changes needed to bring about a more sustainable yet equitable world.

Progress since 2010 is reflected by the inclusion of the latest research and thinking, selected and discussed to put the advances concisely in a much wider setting – historic, scientific, technological, intellectual and societal. The treatment also examines the complexities and additional challenges arising from public and media attitudes to science and technology and associated controversies and from the difficulties in reconciling environmental protection and global development.

While the book stresses the central importance of rigour in the collection and treatment of evidence and reason in decision-making, to ensure that it meets the needs of an extensive community of students, it is broad in scope, rather than deep. It is, therefore, appropriate for a wide audience, including all practising scientists and technologists.

1

Scope of the Book

‘For every human problem, there is a neat simple solution. And it is always wrong!’
H. L. Mencken

This single-authored treatment of the contributions of chemistry to the development of sustainable technologies necessarily reflects the selections and the judgments of the author. The central role of fundamental physical principles, and of rigour and reason in the treatment and use of scientific evidence, dictates the selection of material covered, how it is presented and exemplified and the order in which it is appears.

The first edition of Chemistry for Sustainable Technologies: A Foundation was intended to be a different type of text book that considered sustainability from the perspective of the chemical sciences put in the context of basic concepts from other disciplines and domains. It was therefore broader than more specialist books though it sought not to lose sight of chemical fundamentals. The more questioning approach taken in the first edition, particularly to the substantive contributions of green chemistry, has now been more widely adopted. This edition will continue to stress the importance of an unwavering focus on rigour, reason and open-mindedness to help make sense of the avalanche of scientific publication, associated speculation, comment and polemic (and fake news). It will bring the entire treatment up-to-date (as far as this is possible for a text book) with a selection of the latest evidence, examples and ideas.

To navigate rationally the complex issues and manifold perspectives that characterise sustainability and sustainable development, a clear prior understanding is necessary of the scientific method and its development (and, as a consequence, an appreciation of the need to consciously think as scientists). Unfortunately this is something rarely taught formally or explicitly in undergraduate chemistry courses. By encouraging the use of these tools, it is hoped that the reader will be better able to get to (and to interpret) the underlying evidence behind the images and headlines seen in the media and on the internet.

The book more conventionally does the following, using up-to-date examples:

• explains the concepts and terminology of sustainability and sustainable development and their associated complexity, inter-relatedness and uncertainty;
• highlights the necessary (if sometimes contested) role of science and technology in the transition towards sustainable development;
• exemplifies new approaches to chemistry and chemical technology driven by the need for, and requirements of, more sustainable chemical and energy technologies; and
• illustrates the central role of metrics in the critical and comparative assessment of these technologies and their sustainability.

The aim is to equip the reader to:

• understand the basic terminology of sustainable development and chemistry for sustainable technologies;
• appreciate the non-rigorous nature of much of this terminology and its consequences;
• recognise the importance of universally-applicable thermodynamic principles in judgements about what may be considered sustainable (or even possible);
• evaluate the strengths and weaknesses of green chemistry;
• appreciate the importance of catalysis, process technology and the use of alternative feedstocks and energy sources in developing sustainable chemical technologies and the challenges associated with the transition from fossil-fuel dependency;
• place chemistry and chemical technology in a wider technological and societal context; and
• gauge the nature and scale of current global energy, feedstock and material needs and practical constraints on the delivery of sustainable alternatives.

The topic of sustainable development, the factors driving it and efforts being made to bring it about continue to change over time. To maintain currency, I update the list of websites and weblinks that may be of use as starting points to supplement the material to be found in the academic peer-reviewed literature. The extra care needed when using such web-based and increasingly open-sourced material is discussed in Chapter 13.

To keep the scope of this treatment manageable while meeting the book's prime purpose to provide a foundation to the topic of chemistry for sustainable development, there will be some matters that are not explored in the detail required to satisfy every reader. In these instances, I point to accessible and peer-reviewed sources of additional information that readers could profitably explore further.

The selection of topics addressed and the examples used to illustrate them are governed, to a large extent, by the fact that this book is aimed primarily at chemists and chemical technologists. The selection I have made is different from that which those with other specialisms and interests might have made. That this is so is a reflection of the complexity and inter-relatedness of sustainable development and sustainability (Glaze¹ called this ‘hyperdisciplinarity’), something that it is important, at the outset, to recognise. The role of chemistry, and of science itself, is shown to be critically important. While absolutely necessary, however, neither is sufficient.

The main themes covered by this book include:

• Sustainability and sustainable development: the origins and impact of climate change.
• Science and knowledge: what is it? Use and misuse.
• The Anthropocene and the age of technology; the scale of energy and material use and its implications; carrying capacity of the Earth; ‘tipping points’.
• Earth systems science; environmental chemistry.
• Waste and its minimisation; pollution and its prevention.
• Metrics, life-cycle analysis and chemical technology: the process and product chain; technological integration; industrial ecology and the circular economy.
• The central importance of the Second Law of Thermodynamics: the concept of exergy.
• Green chemistry: principles and pitfalls; contributions from new chemistry; the central importance of catalysis.
• Energy sources, transformation and storage: prospects and timescales.
• Renewable feedstocks: the transition from fossil sources; biomass; biofuels; the ‘biorefinery’.
• The chemist as citizen: a statement of the challenges.

An examination of the list of contents will show that these themes follow roughly the order in which the chapters appear, with the basic ideas necessary for an appreciation of later material coming first. For reasons of space, some examples used to illustrate these basic ideas and their relevance are not necessarily repeated when a related topic is later considered in detail. Other cases, such as that of solvents derived from biomass, which are relevant across several chapters, are discussed in detail in only one (Chapter 12). One centrally important topic, the formation, function, impact and processing of carbon dioxide, is treated in a number of chapters where, in my view, the discussion sits most comfortably. Whatever the readers’ area of expertise or interest, and whether the chapters are read sequentially or are dipped into occasionally, from the outset, topics and sections are cross-referenced at critical points in the text, to supplement the index and list of contents and to aid navigation.

The underlying theme running through the book is chemistry's central importance both to our attempts to understand the environment and the lifeforms that populate it, as well as to our efforts to develop ways to make the demands of the human population on the planet's resources (and its associated impact) more sustainable. The technological application of chemistry requires some basic understanding of process engineering and process economics and these are introduced as part of the foundation that represents the purpose of this book. Importantly, no claim that a chemical product, transformation or process is either ‘green’, sustainable, or eco- or energy efficient (or environmentally ‘friendly’) should be made or remain unchallenged (preferably, not published) without well-founded evidence of its scalability that addresses the likelihood that it could be produced or operated practically on an industrial scale. Furthermore, this foundation also encompasses the economic and social context (and associated political ramifications) of technological development, particularly relating to the challenge of climate change.

The book tries not to be polemical: it takes no position in areas of controversy, but seeks to reflect my best personal assessment of the consensus position. It is worth pointing out that a consensus view (such as that which prevailed when it was believed that the Earth was the centre of the solar system) can be wrong and those seeking to change it can appear to be outlandish, even dangerous, mavericks² who challenge established authority. My own view on the anthropogenic (i.e. man-made) contribution to climate change has moved over the last 20 years or so, in the light of the evidence, from a point where I accepted the evidence for climate change with a lack of conviction concerning the role of anthropogenic emissions to a position now where I accept that there is a significant contribution to climate change arising from our emissions of greenhouse gases that requires an urgent, sustained and global response.

While there may be a developing general acceptance that action needs to be taken to ameliorate the situation, it is less likely that there will be a consensus on what form (or forms) this action might take. However, my hope is that readers will be assisted in arriving at a rational view for themselves based on the scientific evidence as to what the current position is that may help to inform their judgements about how to proceed.

We are, in historical terms, beginning the journey to sustainability, so it is, at present, possible only to frame the very hard questions we need to ask, providing tentative answers to some and not necessarily providing definitive answers to them all. However, because it is possible that we are close to a point of no return (and in no position to judge whether or not, or how close we are), there is a sense of urgency in our search for answers to these questions. I hope that this book will enable those of the new generation who must exercise judgement to develop ‘a deeper kind of prudence’³ and a ‘capacity to worry intelligently’.⁴

References

1. W. H. Glaze, Environ. Sci. Technol., 2001, 35, 471A.

2. N. Winterton, Clean Technol. Environ. Policy, 2007, 9, 153.

3. W. R. Freudenburg, Science, 1988, 242, 44.

4. R. W. Kates, Ambio, 1977, 6, 247.

2

Setting the Scene

‘… out of this nettle, danger, we pluck this flower, safety.’
William Shakespeare (Henry IV Part 1, Act 2, Scene 3).

The practical contribution of chemistry and chemical technology to sustainable development requires an appreciation of the origins, nature, history, scale and timescale of the impact of human kind on the Earth and of the part that scientists and technologists, with those from other disciplines, might play.

2.1 The State of the Planet

Our immediate perceptions of the world about us are governed by what we see directly with our own eyes and the images that the media select for us to see. Both, in their different ways, are incomplete pictures. We attempt to fill in the gaps by seeking out more information and by exercising judgement based on our experience, knowledge and attitudes. This will be supplemented by additional information and insights from other sources, often of varying reliability. However this may be done, it is true to say that many of us, while living longer and more comfortably largely as a result of improvements to our health and well-being arising from the benefits of technology, are increasingly concerned about the Earth's continuing ability to support us all. More recently, we have been exposed to more apocalyptic visions for the future of humankind relating to the consequences of the human contribution to climate change associated with increased emissions of greenhouse gases such as carbon dioxide. This has stimulated debate about the need for action (whether individual or collective; local, national or global) and what form this should take. Further questions have arisen about the nature of society, the economy and the environment, and their future. These components of our world are interconnected and overlapping, complex and dynamic, reflecting the diversity of the ways people have come to live with one another and with the natural world.¹ Any approach to solving the problems of sustainable development needs to reflect on this reality. The broader aspects of this issue have been captured well by Mike Hulme in his book, Why We Disagree About Climate Change,^2a and supplemented in a later article.^2b See ref. ²(c) for a contrary perspective.

Because of the impact that technological development has had on the environment in seeking to meet the needs of a growing population (as illustrated in Figures 2.1–2.3), there is perhaps an understandable view in some quarters that we sho...

Table of contents

• Cover
• Title
• Copyright
• Contents
• 1 Scope of the Book
• 2 Setting the Scene
• 3 Sustainability and Sustainable Development
• 4 Science and Its Importance
• 5 Chemistry of the Environment
• 6 Waste, Energy and the Laws of Thermodynamics
• 7 Measuring Reaction and Process Efficiency
• 8 Chemistry: Necessary for Sustainable Technology, but Not Sufficient
• 9 Processing of Chemicals at Scale
• 10 Catalysis
• 11 Sustainable Energy,1 Fuel and Chemicals
• 12 Biomass as a Source of Energy, Fuels and Chemicals
• 13 The Chemist as Citizen
• 14 Conclusions
• Appendix 1 Units and Abbreviations
• Subject Index