Sy mposiurn
From the chemistry of responsible environmentalism to environmentcllly responsible chemistry
Introducing Green Chemistry in Teaching and Research Terrence J. Collins Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213 The book of science and technology has been written largely in this c e n t u q I t is a periodical in which certain subjects take shape over time in an unfortunate way. Early installments appear to contain entirely beneficial developments, but a s the full story unfolds, unfortunate long-term environmental consequences can become a significant legacy. As the century comes to a close, the public has witnessed the process often enough that concern for the environment has become a n important factor in developments in science and technology In the midst of a more vigorous concern for the environment, several terms have been put forward to capture a n important idea. The terms are "green chemistry", "primary prevention", and "environmentally benign chemistry". They represent the supposition that chemical processes that carry environmental negatives can be replaced with less polluting or nonpolluting alternatives; the hypothesis has been demonstrated to be true in several important cases. This idea is ethically and politically powerful. The term, "green chemistry" is now the most widely used. It is perhaps the strongest of the three because i t associates developments in chemistry with the pastoral longing of modern man. The idea of green chemistry has a n energy that properly belongs i n university research laboratories and classrooms where i t can be nurtured i n the most positive way. I t presents academic chemists with a n opportunity to develop a new and optimistic way of looking a t chemistry and planning to contribute to its future. The principles of green chemistry t h a t can energize our classrooms and bring long-term meaning and direction to a component of academic research await clear definition. What will this subject be like? I will suggest key elements for both the research and the teaching components. The environment calls on the entire research edifice to define long-term strategic goals for green chemistry and to be patient and persistent in achieving them. For example, achieving the efficient technological conversion of solar to chemical energy is a problem i n green chemistry a s much a s in any other field. I t merits Edisonian tenacity until it is solved. Similarly, improving the technology and marketing of solar to electrical energy conversion processes should bring large environmental benefits. The environment calls on professors in their teaching to incorporate green goals into courses without compromising the integrity of chemical knowledge. In my own case, the fear that environmental information would undermine basic chemistry has lessened a s I have discovered the nature of the superb green chemistry that already exists. Green chemistry i s real chemistry where the anecdotal component blends nonintrusively to support what might be considered the basic chemistry. Anumber of examples were described by Cusamano and Trogler in other lectures in this conference. My own interest has been stimulated further as I have begun to appreciate that green chemistry will become
a n intellectually challenging discipline with its own form. Moreover. I believe it is realistic to anticioate that meen chemist6 will lead to successful products and a largemarketplace. In this lecture summary, I will sketch our efforts a t CMU to incoroorate the environment i n a fertile manner into teaching. For lack of space, the research component of the lecture will not be included. The interested reader is referred to a recent review of a program aimed a t producing long-lived, recyclable homogeneous oxidants to minimize metal ion wastes in catalytic oxidations ( I ) . I will begin by describing a course entitled "Introduction to Green Chemistry". The course was delivered i n 1992 and 1993to upperlevel undergraduates and graduate students, in part, as self-preparation for learning how to incorporate the environment more broadly into teaching. I will then introduce CMU's Environmental Institute and its Environmental Initiative called Enuironment across the Curriculum. In this initiative, environmental modules are being prepared for inclusion in courses i n every college i n the university guided by a Steering Committee led by Cliff Davidson, Professor of Civil and Environmental Engineering. I will conclude bv sketchinz a n examole of a module for freshman chemistry classes. A Course Called "Introduction t o Green Chemistry"
The course has the following objectives: 1. To define goals far green research and to consider
evaluation criteria for green reagents. 2. To identify target technologies that realistically might be
replaced by green technologies and ta ponder the alternatives. 3. To describe the features of polluting chemical technologies that have led to their continued use after negative environmental impacts have been discovered. are developed to replace. 5. To challenge students t o think originally about what
green chemistry might become. 6. To introduce students to one or more internationally rec-
ognized scholars on the chemistry or biochemistry of environmental protection. The orincioal source materials are listed in the references (2-91, and some are annotated. The course consisted of thirty 90-minute lectures divided into curriculum tonics a s follows: 1. Current examples ofthe role of catalysis in green chemistry (7 Lectures): Catalysis in the economy; examples of
~rimarvand secandarv . mevention . 2. An overview of energy sources and associated pollution (8 Lectures):Technical description of fossil fuel, nuclear and solar components of the economy, and environmental impacts. ~ntroductionto combudtion and strategies for
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greening of combustion. Approaches t o green energy soul%es 3. Anthropogenruatmu*pl~rr~c pollution 5 lrrrures,. Atmosp h m c chrmlstr) of the CFCb Nitrogen Oxides INO,I tn the Atmosphere 4. Biocatalysis as a route to new chemicals, including perhaps, commodity chemicals (2 Lectures) 5. Introduction to bioremediation (3Lectures) Grading for the course was centered around a n original proposal in green chemistry. Students presented a threepage midterm preproposal that was followed by one-on-one advice sessions with the instructor. Their 40-min class presentations a t the end of the semester were videotaped for one-on-one feedback, and their written 10-15 page proposals were graded. The following were the topics that resulted i n c 0 6 ~ l e t e dproposals: 1. Reducing Ozone Depletion by Replacing CFC's as Refrigerants 2. An Analysis ofAdipic Acid Preparation 3. The Minimization of Sludge Waste fram Wet Pre-formed Sprnv Srruhhing S! s t m i hy llir i,f Chem~calAddmvrs 4. Catalytlr Anubodtes for Toxtc Chemical i)egradot~on 5. Ilwlaormrnt Trchnolom fur Accelerated Rubber Swems 6. ~ i i r o ~ Oxide e n ~ m i s s L nControl with Organic Tertiary Hydroperoxides 7. Recycling of Vulcanized Rubber 8. Plastics Recycling by Selective Dissolution 9. Synthetic Pathways to Tax01 10. Lessons in Environmental Law 11. Biological Degradation of Organic Waste in Emuent from the Brewing Industry
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Environmental Education at CMU While the above course has been developed recently, Carnegie Mellon University has been a center for environmental research and education for decades. Existing environmental education programs a t CMU include a n environmental minor in the engineering, humanities, and MS Droeram social sciences colleges: u , a n interdisci~linarv " in Environmental Science and in Environmental Management: and a ioint-deeree MS Droeram i n Civil Eneineering and in Industrial Administration with a n environmental management soecialization. There are numerous environm e n t z researih topics i n PhD programs throughout the universitv. The facultv h a s been extending this basis throunh t h ~initiiitive : c;;lled .'Environment ~ c r o s the a Curriculum". The specific objectives are the following:
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1. To identify key environmental issues that are important to careers of our undergraduates. The identification procedure is based on oriar exoerienee. on facultv and stuGreen Design Initiative. 2. To integrate these issues into selected courses through modules where there is a "natural fit" with the course material and where the instruetar works closely with faculty from the Environmental Institute. Examoles of courses identifird for modulri m e : freshman intrnductmy en@nerrtny coursei, freshman srwnce courses erpermlly rhrmlirry,, thrrmodynamsr, rransport, flud mrohamcs. electronic devices, semiconductor devices, engineering design and manufacturing, pmbability and statistics, economics, and history 3. To develoo material about these issues far dissemination experiments.
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Journal of Chemical Education
The Greening of Refrigeration: A Module The following is a n outline of a three-lecture module for freshman chemistrv entitled. "The Greening of Refrieeration". The module starts with a n historicalperspect&e of the chemistrv of refrigeration. Refriceration. a technoloeical wonder, has been modified repeatedly over its 150-~&r historv to r e ~ l a c the e refrigerant because of environmental conce&. ~ i f f e r e n trefrigerants have corroded seals and the machinery, cooled inefficiently, decomposed, gagged or killed people, caused explosions, and contributed to stratospheric ozone depletion. Refrigerant molecules are simple entities like NH3, S02, or CFC's such that the green module fits well into structure, bonding, and properties sections of freshman chemistry Moreover, students appreciate the benefits of refrigeration and want to understand the environmental story of the CFC's. The original CFC's were prepared i n a search for the ideal refrigerant. I n general, students are aware of the seriousness of the environmental problems created by CFC's. Here, t h e environm e n t a l story c a n improve f r e s h m a n chemistry. T h e important lesson of the greening of refrigeration for professors is that radicals are vastly more important than we imply from our classical course content. The CFC-refrigeration story best illustrates how nondeliberate negative environmental consequences can he discovered after the use of a chemicallv based technolorn is well established. The topic can be used to show howresearch i n chemistry can lead to effective change to a safer universal technolow. Our research programfits into green chemistry i n the following way. For 15 years, we have been working to produce ligand systems that are stable toward oxidative decomposition in oxidizing environments ( I ) . The approach has led to unprecedented stable high oxidation state transition metal complexes that are models for proposed reactive intermediates i n hioloeical and chemical oxidation processes. This work also is leading to novel homogeneous catalysts for oxidation processes, including C-H bond oxidations. Many oxidation processes are environmentally unfriendlv. We a n t i c i ~ a t ethat bv having verv lone-lived catalytic-and recyclable oxidant"^, we Gill contrihke to minimizing metal ion contamination of the environment, and we will provide more effective processes for utilizing molecular oxygen a s a primary oxidant.
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Literature Cited 1. Collins, T. JAce Chem. Re% I W . 27,279. and refemces therein. 2. CHEMTECH 1992.22.48249. Cusamano, J.A. "New Technologysnd the Envimnmeat". Catalysis is the key to mst.effeetiue envimnmentally compstihle technologies Curamsno kindly provided copier ofslidea for the seminars he had developed in the area. His work and insieht omvided the backemnd for one third of the
6. Greenwood, N. N.; Eamhaw,A. Chemktq oflheEhmmls; Pergamon
Press:Oxiord.
1984. 7. Manahan. S. E. Enuimnmntol Chemisfq, 5th ed.; Lewis Publishers: Chelsea, MI, 1991.
8.Zahnewski. F S.Prineipl~~ofEnvironmrntcr1 Tarico1opv:ACS:Washington, DC, 1991. 9. Frallsto da Silva, J. J. R.:Williams. R.J. P The Biological Cl~amislqof the Elemenb: TheInorgonic Chemistry ofLife:Clarendon Press: Oxford, 1991.
