Since the environment was a popular cause in Catnip’s recent diary What’s Your Main Political Concern, and I was encouraged by fellow frogponders (What do we call ourselves, anyway?) to post on the subject, here it comes… I look forward to your thoughts.
Cross-posted at Greenstate.
Green Chemistry – From Oxymoron to the Future of Industry?
A generation ago, the phrase “green chemistry” might justifiably have been taken as an oxymoron. But today, a new generation of chemists and chemical engineers is working to mold their industry into a more environmentally benign force while still meeting society’s demands for effective products. This week, the researchers, government officials, and industry figures on the frontiers of this movement met in Washington, DC for the 2nd International Conference on Green and Sustainable Chemistry and the 9th Annual Green Chemistry and Engineering Conference. As environmentally-concerned citizens who both use the products from industry yet want industry to “clean up its act,” it’s worth taking a closer look at what these folks are up to.A generation ago, the phrase “green chemistry” might justifiably have been taken as an oxymoron. But today, a new generation of chemists and chemical engineers is working to mold their industry into a more environmentally benign force while still meeting society’s demands for effective products. This week, the researchers, government officials, and industry figures on the frontiers of this movement met in Washington, DC for the 2nd International Conference on Green and Sustainable Chemistry and the 9th Annual Green Chemistry and Engineering Conference. As environmentally-concerned citizens who both use the products from industry yet want industry to clean up its act, it’s worth taking a closer look at what these folks are up to.
What is green chemistry?
The American Chemical Society has posted “Twelve Principles of Green Chemistry” on their website; these principles serve as a summary of what the movement is attempting to accomplish:
1. Prevention
It is better to design an industrial process to prevent waste from being created at all than to treat it or to clean it up after it has been created. (This process is discussed well in the recent book Cradle to Cradle, which advocates designing industrial processes after natural systems, where there is no toxic waste – unused materials become food for something else in the ecosystem.)
2. Atom Economy
Kind of a geeky sounding goal; this principle states that processes should be designed to incorporate as much of the raw materials used in the process into the final product as possible.
3. Less Hazardous Chemical Syntheses
Processes should be designed to use and generate compounds of little or no toxicity to human health and the environment, wherever possible.
4. Designing Safer Chemicals
Chemical products should be designed to perform their desired task while minimizing their toxicity.
5. Safer Solvents and Auxiliaries
Processes should be designed to minimize the use of solvents, separation agents, etc. wherever possible, and to use non-harmful materials where essential.
6. Design for Energy Efficiency
Processes should be designed to minimize energy use, as this will reduce environmental and economic impacts. This would include designing processes to operate without heating, cooling, or changes in pressure.
7. Use of Renewable Feedstocks
Processes should be designed to use renewable materials as feedstocks, rather than depleting resources, wherever technically and economically possible.
8. Reduce Derivatives
Processes should be streamlined to minimize use of steps that require additional reagents that do not contribute directly to the final product but end up as waste.
9. Catalysis
Catalysts are preferable to use wherever possible, as a catalyst molecule reacts over and over thousands of times generating a product, thus minimizing waste.
10. Design for Degradation
Products should be designed so that at the end of their function they break down into harmless materials that do not persist in the environment.
11. Real-time analysis for Pollution Prevention
Analytical methods need to be further developed to allow real-time, in-process monitoring and control to prevent 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 minimize the potential for chemical accidents, including releases, explosions, and fires.
Some might say this is merely tweaking the status quo, when a revolution is needed to an all-organic, totally environmentally benign society. The questions remain however, of whether that is feasible in one fell swoop, and is society as a whole ready to go to there. And in the meantime we’ve had how many hazardous chemical tank truck wrecks? How many rail cars of chlorine derail? How many poor communities with elevated cancer rates?
When mosquitoes carrying West Nile virus arrive, the majority of folks are going to want their neighborhood sprayed for mosquitoes. Might it not be a good thing to have as environmentally benign a pesticide as possible available, since when that day arrives it will be too late for a public education campaign on the benefits of purple martins? (Not that this is an either-or choice by any means.) It seems that the principles above, if put into practice and not mere “greenwashing” would be an important step in the direction of increasing society’s options for meeting our needs and challenges in an environmentally benign way. Perhaps it is the coming of age and into leadership positions of the generation of chemists and chemical engineers whose education included Bhopal and Love Canal that is moving this viewpoint into the mainstream.
It may be time to face reality and admit that getting to the post-industrial utopian ideal (however defined) is a process that is going to take decades of public education, reworking economic incentives, and legislation. In the meantime we are in the society we are in, and we might as well try and conduct business in this society in as environmentally benign a manner as possible, to buy us the time we need for continued societal evolution on the good green path. In fact, this evolution may become the more sustainable, less controversial path to attain the same goal.
What are some specific examples of this worldview in practice? How are the more-forward thinking elements of the chemical industry making a real-world difference? Since 1996, EPA’s Office of Pollution Prevention and Toxics has presented annual awards in the “Presidential Green Chemistry Challenge.” Winners include the following:
* Rohm and Haas Company won a 1996 award for the development of an environmentally safe marine antifoulant. The compound tributyltin oxide (TBTO) has long been used to prevent fouling, the growth of plants and animals on the hull of a ship below the waterline. Fouling results in drag, leading to increased fuel use, and thus contributing to global warming and acid rain. Unfortunately TBTO, while effective, is also acutely and chronically toxic in the environment, bioaccumulative, and persistent. For this reason, legislation was passed in the US to restrict use of tin antifoulants in 1988. The alternative developed by Rohm and Haas, marketed as Sea-Ninetm antifoulant, is still acutely toxic (that is its purpose), but degrades very rapidly with a half-life of one day in seawater and one hour in sediment. It is essentially free of bioaccumulation and chronic toxicity effects.
* A small business, SC Fluids, Inc., won a 2002 award for development of a process to use supercritical (a high pressure state combining properties of liquid and gas phases) CO2 for cleaning integrated circuits during manufacture, replacing a process which used large amounts of purified water, hazardous solvents and corrosive chemicals while also resulting in a streamlined, faster process.
* Chemical Specialties, Inc. won a 2002 award for development of a more environmentally benign substitute to CCA (chromated copper arsenate) for treating lumber for outdoor use. Since over 90% of the arsenic used in the US is used in preserving lumber, an alternative process allows significant reductions in the amount of this toxin reaching the environment, as well as of hexavalent chromium, another toxic and carcinogenic component of the traditional CCA formulation.
* Bristol-Meyers Squibb won a 2004 award for developing a way to culture cells of the pacific yew tree, from which the anti-cancer drug Taxol is derived, in large fermentation tanks. Previously, this chemical had to be obtained by stripping the bark from yew trees, killing them. Yews take 200 years to mature and are part of a sensitive ecosystem.
The point is that traditional pollution prevention efforts, while laudable, merely fine-tune the existing system without examining the design flaws at their source – the design of the overall process of creation, use, and final status of a product. Reforms that assume an inherent antagonism between nature and industry end up as commercial and environmental dead ends. A brighter future may be possible: Do we know enough to say with certainty that we cannot transcend our self-image as a curse upon the earth – if we accept our place within the overall ecology in conducting our activities and learn from nature in designing our products?
At its best, the green chemistry effort strives to live up to the goal described by William McDonough and Michael Braungart (authors of Cradle to Cradle) in the book Environmentalism and the Technologies of Tomorrow:
“What if our designs were so inherently productive and healthful they allowed us to celebrate the things we make? A strategy we call ‘cradle to cradle design’ allows us to do so. It rejects the assumption that the natural world is inevitably destroyed by human industry… Conventional industrial design is flawed because it developed in a time when few understood the dynamic relationship between economy and ecology, or the principles of the earth’s natural systems.”
Could this philosophy be misused by technical triumphalists? Of course, and I’m not at all advocating that the folks at the various environmental organizations all pack it in and call it a day. On the other hand, I think it is a hopeful sign that the goals and beliefs of the same environmentalists are working their way even into the least expected parts of the wider culture. Those of us who are not ashamed to wear the label “environmentalist” should welcome allies wherever we can find them, and make common cause wherever we can.
Any major change in society takes decades to implement if it is to be permanent, and will result in changes to all aspects of our world. Green chemistry just might be another step forward in that long march.
