Introduction to Sustainable Development for Engineering and Built Environment Professionals 

Unit 2 - Learning the Language

Lecture 8: Green Chemistry and Engineering - Benign by Design

Chemical engineers have much to contribute in a world that is moving towards sustainability. Indeed our role is somewhat unique. We possess a detailed knowledge of process engineering coupled with an understanding of novel science and technology across a broad range of disciplines. Chemical engineers can utilise this potent mix of skills to develop new approaches to some of our most challenging global problems… We are already seeing the influence of the new forces at work on our profession. Leading educational and research institutions, such as Oxford University, have introduced sustainable development priorities in chemical engineering education, focusing on hydrogen as fuel, emissions reduction, sequestration, photo-voltaics, and life cycle analysis.

Dr Robin Batterham, President International Council of Chemical Engineering, 2005[1]
         

Educational Aim

 

To provide an overview of how chemical engineers, often working with chemists, are applying Green Chemistry and Green Engineering principles to play a key role in assisting business, the economy and society achieve sustainable development.

Textbook Readings

Collins, T. (2001) ‘Toward Sustainable Chemistry’, Science, vol 291, pp 48-49. Accessed 3 January 2007.

Hargroves, K. and Smith, M.H. (2005) The Natural Advantage of Nations: Business Opportunities, Innovation and Governance in the 21st Century, Earthscan, London:

1. Chapter 3: Asking the Right Questions Table 3.2 (1 page), p 49.
   
   
2. Chapter 3: Asking the Right Questions Table 6.6 (2 pages), pp 52-53.
   
   
3. Chapter 6: Natural Advantage and the Firm (1 page), p 97.

Learning Points

1. Advances in the science of chemistry and chemical engineering have unleashed new ways to improve people’s quality of life and improve global prosperity. The products of the global chemical industry are worth US$1500 billion annually, and account for approximately nine percent of world trade in manufactured goods.

2. While it is true that the chemical industry has contributed significantly to increased prosperity globally and improved quality of life, it has come at a cost, as Rachel Carson’s classic publication Silent Spring[2] demonstrated, with chemicals, there are risks. Estimates of the costs of cleaning up existing hazardous waste sites range in the hundreds of billions of dollars. Cleaning up chemical messes is growing ever more costly.

3. Chemical engineers are in a position to make a significant contribution to achieving sustainable development profitably in numerous ways through contributing to sustainable chemical plant design, improving process operation, eliminating the need for toxic chemical usage and dramatically reducing waste.

4. Chemical engineers, practising Green Chemistry and green chemical engineering principles, have the potential to play a significant role to help achieve sustainability. This is because chemical processes underpin all forms of industry. The key role of chemical engineers to achieve sustainable development is recognised by numerous chemical and chemical engineering organisations[3] and by many chemical companies.

5. In 2001, in Melbourne Australia 20 national chemical engineering institutional bodies committed to sustainability through the Melbourne Communiqué. This lecture seeks to overview the latest insights in how chemical engineers can truly help society achieve ecological sustainability and thus fulfil their commitment made in the Melbourne Communiqué.

6. As Terry Collins wrote in Science,[4] chemical engineers and chemists have a huge role to play in at least three significant areas:

1. First, renewable energy technologies will be the central pillar of a sustainable high-technology civilisation. Chemists can contribute to the development of the economically feasible conversion of solar into chemical energy and the improvement of solar to electrical energy conversion.[5]
   
   
2. Second, the reagents used by the chemical industry, today mostly derived from oil, must increasingly be obtained from renewable sources to reduce our dependence on fossilised carbon. This important area is beginning to flourish, but unfortunately there is not the room to cover it in detail in this portfolio.
   
   
3. Third, polluting technologies must be replaced by benign alternatives. This field is receiving considerable attention, but the dedicated research community is small and is merely scratching the surface of an immense problem.

7. As discussed in the previous lecture this field also has a key role to play in operationalising Biomimicry. But also chemical engineers, chemists and the chemical industry are realising that Biomimicry offers a remarkable strategy for innovation. The UK Chemical Industry acknowledged this in their Vision for the Sustainable Production and Use of Chemicals[6] where they stated, ‘It is very difficult to achieve step-change improvements in environmental and economic performance through incremental improvements in conventional production technologies. For a growing number of chemical companies, inspiration is coming from Biomimicry.’

8. The Green Chemistry and Green Engineering ideas and initiatives that are now prominent globally began through the pioneering work of people like Paul Anastas, known as the father of Green Chemistry and Michael Braungart, co-author of Cradle to Cradle. Globally there are now significant networks, research institutions, companies, and government agencies working on Green Chemistry and green chemical engineering.

9. In Green Chemistry and Green Engineering, an ideal chemical reaction (or set of reactions) would have the following characteristics: [7]

1. Simplicity
   
   
2. Safety
   
   
3. High yield and selectivity
   
   
4. Energy efficiency
   
   
5. Use of renewable and recyclable reagents and raw materials.

Therefore in achieving and implementing such reactions in industry, chemical engineering is set to make a profound contribution to sustainable development.

10. This lecture will provide an overview of some examples of where Green Chemistry and Green Engineering principles are being applied. Just a sample of some of the areas where such principles are being applied include:

1. Toxics in the Environment: designing chemical products that are inherently less toxic and ‘benign by design’.[8] This also includes designing chemical systems to produce consumer products that require less energy, produce less or no toxins and are then reusable or recyclable.
   
   
2. Energy Production: providing alternative means of energy production through, for example, using materials developed for photovoltaic cells and the enabling technologies to make the manufacturing of hydrogen fuel cells more feasible.[9]
   
   
3. Resource Depletion: using biowastes to develop alternatives to current natural resources experiencing rapid depletion. Nanotechnologies could help to improve our ‘materials economy’, providing the same performance with less material.[10]
   
   
4. Sustainable Food Production: using agricultural chemistry to develop pesticides that do not harm or persist in the environment, and more effective and less chemical fertilisers.[11]
   
   
5. Climate Change: using materials such as polymers and cement to absorb CO2, thereby improving performance while also acting as a ‘sink’ for carbon dioxide in the atmosphere. Infrastructure surfaces (such as roads and building walls) can also be designed at the molecular level to absorb CO2 emissions while improving performance.[12]

11. The new objective is to achieve Green Chemistry and Green Engineering that is ’benign by design’ when inventing new processes, or when addressing manufacturing problems associated with ‘end-of-pipe’ treatment.[13]

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Brief Background Information

 

In 2001, in Melbourne Australia 20 national chemical engineering institutional bodies committed to sustainable development through the Melbourne Communiqué, stating that,[14]

In meeting society’s needs we are committed to designing processes and products that are innovative, energy-efficient and cost-effective, and that make the best use of scarce resources. We are committed to the highest standards of personal and product safety. We seek to eliminate waste and adverse environmental effects in the development, manufacture, use and eventual disposal of the products of society.

The Melbourne Principles were Agreed in Melbourne at the Sixth World Congress of Chemical Engineering, September 27, 2001, and signed by: the Czech Society of Chemical Engineering; Canadian Society for Chemical Engineering; Institution of Chemical Engineers; Society of Chemical Engineers New Zealand; South African Institution of Chemical Engineers; European Federation of Chemical Engineering; Asian Pacific Confederation of Chemical Engineering; Mexican Institute of Chemical Engineers IMIQ; Chinese Institute of Chemical Engineers (Chinese Taipei); Inter-American Confederation of Chemical Engineers; TMMOB, Chemical Engineering Chamber of Turkey; American Institute of Chemical Engineers; DECHEMA Society of Chemical Engineering and Biotechnology; Institution of Chemical Engineers in Australia; Society of Chemical Engineers, Japan; Institution of Engineers (Australia); Hong Kong Institution of Engineers; Socièté de Chimie Industrielle; Chemical Industry and Engineering Society of China; and Socîèté Français de Gènie des Procèdés

In this lecture we will overview the latest insights in how chemical engineers can truly help society achieve ecological sustainability. The commitment outlined here is significant and timely. It is literally impossible to achieve ecological sustainability without the active involvement of chemical engineers.

Sustainable Chemistry – Green Chemistry
Green Chemistry can be defined as ‘the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances’.[15]

Green Chemistry practices are governed by 12 Principles:[16]

1. Prevention: It is better to prevent waste at the outset than to treat or clean it up.
   
   
2. Atom Economy: Synthetic methods require maximal use of all materials in the chemical process into the final product.
   
   
3. Less Hazardous Chemical Syntheses: Synthetic methods should be designed to contain little or no toxic materials hazardous to human health and the environment.
   
   
4. Designing Safer Chemicals: Chemical products should be designed for safety as well as performing their intended function.
   
   
5. Safer Solvents and Auxiliaries: The use of auxiliary substances (e.g. solvents, separation agents) should be kept at a minimum.
   
   
6. Design for Energy Efficiency: The economic and environmental impacts associated with the energy requirements for chemical processes should be recognised and minimised; where permissible chemical processes should be conducted in ambient pressure and temperature.
   
   
7. Use of Renewable Feedstocks: Raw materials sourced from renewable feedstocks should be used wherever technically and economically practicable.
   
   
8. Reduce Derivatives: Unnecessary derivisation (eg. temporary modification of physical/chemical processes) should be minimised or avoided if possible, as such steps can generate waste through the use of additional reagents.
   
   
9. Catalysis: Catalytic reagents are superior to stoichiometric reagents.
   
   
10. Design for Degradation: Chemical products should be designed for decomposition into benign substances at the end of their functional life, to prevent their persistence in the environment.
    
    
11. Real-time analysis for Pollution Prevention: Analytical methodologies that allow for real-time, in-process monitoring and control should be used in order to avoid the formation of hazardous substances.
    
    
12. Inherently Safer Chemistry for Accident Prevention: Substances and the form of a substance used in a chemical process should be chosen to minimise the potential for chemical accidents, including releases, explosions, and fires.

The Global Green Chemistry Network
There are currently over 25 research institutions across Europe, the UK, North America, South America, West Africa and India who are focused on the development of sustainable chemistry. The Centre for Green Chemistry[17] in the School of Chemistry at Monash University (Australia) is in the forefront of innovation in Green Chemistry. Established in January 2000, with the goal of providing a fundamental scientific base for future green chemical technology, the Centre has a primary focus on Australian industry and Australian environmental problems. Among emerging Green Chemistry centres worldwide, the Australian Centre is noteworthy for its broad spectrum of research interests, including benign technologies for corrosion inhibitors, gold processing, and greener reaction media for chemical synthesis, to name a few.

The 12 Green Chemistry Principles, and the field of knowledge that is growing based upon them, are helping to guide chemists and chemical engineers in their efforts to assist industry in its drive towards sustainability. The Green Chemistry principles and this new field of knowledge are helping to guide efforts in the following areas:

• Green Chemistry seeks to achieve waste reduction through improved atom economy[18] (that is, reacting as few reagent atoms as possible in order to reduce waste) and reduced use of toxic reagents for the production of environmentally benign products.
  
  
• Green Chemistry and Green Chemical Engineering seeks to utilise catalysts to develop more efficient synthetic routes and reduce waste by avoiding processing steps.[19] Synthetic strategies now employ benign solvent systems, such as ionic water,[20] and supercritical fluids, such as carbon dioxide.[21]
  
  
• Solvent free methods for many reactions are also being tested, as have biphasic systems, to integrate preparation and product recovery. For example, phases of liquids that separate are going to be much easier to recover without needing an additional extractive processing step.
  
  
• In addition, there has been significant research into utilising high-temperature water and microwave heating, sono-chemistry (chemical reactions activated by sonic waves) and combinations of these and other enabling technologies.[22]
  
  
• Much work is also being done to harness chemicals for common reactions from renewable biomass feedstocks. For instance in 1989, Harry Szmant[23] reported that 98 percent of organic chemicals used in the lab and by industry are derived from petroleum. The Netherlands Sustainable Technology Development[24] project has found that, in principle, there is sufficient biomass production potential to meet the demands for raw organic chemicals from these renewable chemical feedstocks.[25]

Case Study: Argonne National Lab
An excellent example of Green Chemistry is the technology developed by Argonne National Lab, a winner of the 1998 USA President’s Awards for Green Chemistry.[26] Every year in the United States alone, an estimated 3.5 million tons of highly toxic, petroleum-based solvents are used as cleaners, degreasers, and ingredients in adhesives, paints, inks, and many other applications. More environmentally friendly solvents have existed for years, but their higher costs have kept them from wide use.

A technology developed by Argonne National Labs produces non-toxic, environmentally friendly ’green solvents’ from renewable carbohydrate feedstocks, such as corn starch. This discovery has the potential to replace about 80 percent of petroleum-derived cleaners, degreasers and other toxic and hazardous solvents. The process makes low-cost, high-purity ester-based solvents, such as ethyl lactate, using advanced fermentation, membrane separation, and chemical conversion technologies. These processes require very little energy and eliminate the large volumes of waste salts produced by conventional methods. This method of producing biodegradable ethyl lactate solvents can also cut the price by up to 50 percent, from US$1.60-$2.00 per pound to less than US $1.00 per pound. Overall, the process uses as much as 90 percent less energy and produces ester lactates at about 50 percent of the cost of conventional methods.

The lactate esters from this process can also be used as ’platform’ building blocks to produce polymers and large-volume biodegradable oxy-chemicals, such as propylene glycol and acrylic acid. Markets for these biodegradable polymers and oxy-chemicals might soon surpass those of green solvents.

Industry Take Up
Costs of environmental remediation activities are in the range of US$100 billions. Many individual chemical companies have budgets for environmental compliance programs that are as large as their budgets for research and development. A high priority is now placed on developing solutions to avoid waste remediation costs, through waste prevention. Many chemical and related industries realise that re-designing waste out of the initial process will not only save significant costs but can also result in greater profits. The chemical industry has turned to research institutions for guidance, utilising insights from the new fields of Green Chemistry[27] and Green Engineering[28]. These are new approaches to industrial chemistry and engineering that seek to reduce or eliminate the use or generation of hazardous substances in the design, manufacture and application of chemical products.

The objective is to be ’benign by design’ when inventing new processes, or when addressing manufacturing problems associated with ‘end-of-pipe’ treatment.[29] US Presidential Green Chemistry award winner Barry Trost, writes,[30]

In focusing on immediate problems, the implemented solution sometimes ignores the question of what new problems arise as a result of the solution. In short, solving one problem frequently creates another… Establishing the safety of the final end use compounds has been a key part of the process of developing new products for some time. On the other hand, developing the chemical processes by which the end use products are made, has not been a generally recognized part. As we understand more about the broad implications of potential solutions, the real cost becomes more apparent and a new driver for innovation… Making chemical manufacturing more environmentally benign by design must now become an integral part of the product development process.

Green Chemistry and Green Engineering offer chemical engineers a field of expertise and knowledge of how to do this. Since the inception of Green Chemistry[31] in the 1990’s, its philosophies have had a significant impact, assisting the chemical industries to leap toward a more sustainable future. As we will show, such exciting results and progress gives government, industry and academia much to work together on this century to create truly sustainable solutions.

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Key References

- Green Chemistry Institute (n.d.) Introductory Green Chemistry Articles, comprehensive online papers that provide an overview of the field. Accessed 3 January 2007.

- Anastas, P.T. and Warner, J.C. (1998) Green Chemistry: Theory and Practice, Oxford University Press, New York.

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Key Words for Searching Online

Green Chemistry Institute, Anastas, Green Chemistry Principles.

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[1] Dr Robin Batterham (2006) Embracing the challenges of chemical industry sustainability, November 26 (accessed January 2007). (Back)

[2] Carson, R. (1962) Silent Spring, Houghton Mifflin, Boston. (Back)

[3] As the Johannesburg summit approaches, chemical industry associations including the American Chemistry Council (ACC), the Canadian Chemical Producers Association (CCPA), the Chemical Industries Association of the U.K. (UKCIA), and the European Chemical Industry Council (CEFIC) are planning their reports to delegates. (Back)

[4] Collins, T. (2001) ‘Toward Sustainable Chemistry’, Science, vol 291, pp 48-49. (Back)

[5] Jones, D. (2000) ‘Hydrogen Fuel Cells for Future Cars’, ChemMatters, December 2000, pp 4-6. Accessed 26 November 2006. (Back)

[6] Forum for the Future & Chemistry Leadership Council (2005) A vision for the sustainable production & use of chemicals, on behalf of the Chemistry Leadership Council. Available at http://www.chemistry.org.uk/pages/8/press/9308_chemistry.pdf. Accessed 26 November 2006. (Back)

[7] Allen, D.T. and Shonnard, D.R (2002) Green Engineering: Environmentally Conscious Design of Chemical Processes, Prentice Hall, New Jersey, Chapter 7: Green Chemistry. (Back)

[8] Ibid. (Back)

[9] Lankey, R.L. and Anastas, P.T. (2002) Advancing Sustainability through Green Chemistry and Engineering, Oxford University Press, Oxford, pp 4-6. (Back)

[10] Ibid. (Back)

[11] Ibid. (Back)

[12] Ibid. (Back)

[13] Anastas, P. and Williamson, T. (1998) Green Chemistry, Frontiers in Design Chemical Synthesis and Processes, Oxford University Press. (Back)

[14] World Congress of Chemical Engineering (2001) Melbourne Communiqué at the 6th World Congress of Chemical Engineering, September 27, Melbourne. Accessed 3 January 2007. (Back)

[15] Anastas, P., Heine, L., Williamson, T. and Bartlett, L. (2000) Green Engineering, American Chemical Society, November. (Back)

[16] Anastas, P. T. and Warner, J. C. (1998) Green Chemistry: Theory and Practice, Oxford University Press, New York, p 30. (Back)

[17] See The Centre for Green Chemistry in the School of Chemistry, Monash University at http://www.chem.monash.edu.au/green-chem/. Accessed 3 January 2007. (Back)

[18] Trost, B. (1995) ‘Atom economy - A challenge for organic synthesis: Homogeneous catalysis leads the way’, Angewandte Chemie International Edition, vol 34, p 259. (Back)

[19] Strauss, C. (1999) ‘Invited Review. A Combinatorial Approach to the Development of Environmentally Benign Organic Chemical Preparations’, Australian Journal of Chemistry, vol 52, p 83. (Back)

[20] Breslow, R. (1998) ‘Water as a solvent for chemical reactions’, in Anastas, P. and Williamson, T. (2000) Green Chemistry, Frontiers in Design Chemical Synthesis and Processes, Oxford University Press, Chapter 13; Li, C. (2000) ‘Water as Solvent for Organic and Material Synthesis’, in Anastas, P., Heine, L., Williamson, T. and Bartlett, L. (2000) Green Engineering, American Chemical Society, November, Chapter 6. (Back)

[21] Hancu, D., Powell, C. and Beckma, E. (2000) ‘Combined Reaction-Separation Processes in CO2’, in Anastas, P. Heine, L. Williamson, T. and Bartlett, L. (2000) Green Engineering, American Chemical Society, November, Chapter 7. (Back)

[22] Strauss, C. (1999) 'Invited Review. A Combinatorial Approach to the Development of Environmentally Benign Organic Chemical Preparations', Australian Journal of Chemistry, vol 52, p 83. (Back)

[23] Szmant, H. (1989) Organic Building Clocks of the Chemical Industry, Wiley, New York, p 4. (Back)

[24] Weaver, P., Jansen, J., van Grootveld, G., van Spiegel, E. and Vergragt, P. (2000) Sustainable Technology Development, Greenleaf Publishers, Sheffield, UK. (Back)

[25] Okkerse, C. and van Bekkum, H. (1997) ‘Towards a plant-based economy?’ In: Van Doren H.A. and van Swaaij A.C. (eds) Starch 96 – the book, The Carbohydrate Research Foundation, Zestec. (Back)

[26] U.S. EPA Presidential Green Chemistry Awards (1998) 1998 Greener Reaction Conditions Award. Available at http://epa.gov/greenchemistry/pubs/pgcc/winners/grca98.html. Accessed 3 January 2007; Argonne National Laboratory (n.d.) Ethyl Lactate Solvents. Accessed 3 January 2007. (Back)

[27] See The Green Chemistry Institute at http://acswebcontent.acs.org/home.html. Accessed 3 January 2007. (Back)

[28] Anastas, P., Heine, L., Williamson, T. and Bartlett, L. (2000) Green Engineering, American Chemical Society, November. (Back)

[29] Anastas, P. and Williamson, T. (1998) Green Chemistry, Frontiers in Design Chemical Synthesis and Processes, Oxford University Press, NY. (Back)

[30] Quoted from the foreword to Anastas, P.T. and Williamson, T.C. (1998) Green Chemistry, Frontiers in Design Chemical Synthesis and Processes, Oxford University Press, NY. (Back)

[31] Anastas, P.T and Kirchhoff, M.M. (2002) ‘Origins, Current Status, and Future Challenges of Green Chemistry’, Accounts of Chemical Research, vol 35, pp 686-694, American Chemical Society. This is one of the most recent and up to date summaries of key developments in the field of green chemistry. (Back)

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The Natural Edge Project Engineering Sustainable Solutions
Program is supported by the Australian National Commission
for UNESCO through the International Relations Grants
Program of the Department of Foreign Affairs and Trade.