Green chemistry Industrial examples

The most widely used homogeneous catalysts are simple acids and bases which catalyse well-known reactions such as ester and amide hydrolysis, and esterification. Such catalysts are inexpensive enough that they can be neutralized, easily separated fi om organic materials, and disposed of. This, of course, is not a good example of green chemistry and contributes to the huge quantity of aqueous salt waste generated by industry. 

Green chemistry aims to design the hazards out of chemical products and processes, including solvents. With ionic liquids, you do not have the same concerns as you have with, for example, volatile organic solvents, which can contribute to air pollution. Ionic liquid chemistry is a very new area that is not only extremely interesting from a fundamental chemistry point of view, but could also have a very large impact on industry. 

Similarly, the various EU directives that mandate substance bans have initiated wide scale research and development of alternative materials. Lead is a case in point. Lead has been widely used in the electronic industry in solders. Lead-free solders have existed for many years but it was the mandate in the Restriction of use of certain Flazardous Substances Directive (RoHS) to have products free of lead by July 2006 that spurred industry research, planning and adoption of the substitutes. Annex I lists examples of Green Chemistry case studies where research was stimulated in response to legislation targeting hazardous materials. 

The chemical industry is often the strongest link in the supply chain since they provide the chemical formulations to their buyers and are in control of research into alternatives. The recent emergence of Green Chemistry and its 12 criteria has spurred innovation into safer chemicals. A few examples illustrate the progress taking place and suggest a wider potential for innovation should more market demand for safer chemicals occur. 

Chemistry of the Environment focuses on the role of chemistry in environmental issues, including air and water pollution, solid wastes, and the relatively new field of green chemistry. The term pollution refers to the release of harmful or ohjectionahle substances into the environment, most commonly as the result of human activities. Some of the most obvious examples of pollution are smoke produced by industrial operations, carbon dioxide and other gases released into the atmosphere as a by-product of burning fuels, silt and sediment washed off land by rainwater, and garbage dumped on land. 

Green chemistry has developed rapidly since the early 1990s and finds increasing attention and application in industry. Its principles and examples of application are summarized in books.2,3 Green chemistry was the topic of journal special issues4,5 and various symposia,6-10 and The Royal Society of Chemistry launched a new periodical with the same title. Issues and actions with respect to the oil industry were discussed.11... 

Handbook of Green Chemistry and Technology, J. H. Clark and D. J. Macquarrie, Eds., Blackwell Publishing 2002, 540 pp., ISBN 0-632-05715-7. This collection of 22 review essays covers all the important areas of green chemistry, including environmental impact and life-cycle analysis, waste minimization, catalysts and their industrial applications, new synthesis methods, dean energy, and novel solvent systems. The chapters are well referenced and contain pertinent examples and case studies. 

First and foremost, I would like to thank all of the students and teaching assistants of Chemistry 337 and 338 at the University of Oregon for teaching me most of what I know about green chemistry. I would also like to thank Drs. Ken Doxsee, Jim Hutchison, and Julie Haack for their help with learning green chemistry. Finally, I would like to thank Drs. Peter Wuts of Pfizer Pharmaceuticals and Dr. Doug E. Frantz of the University of Texas Southwestern Medical Center for their help with some of the industrial examples. 

With the focus on green chemistry, it is actually impossible to think on an industrial chemical reaction, which involves transition metal complexes, that is not efficiently catalytic. The chemical industry demands atom economical reactions, that is, those in which substrates are transformed into products with the only aid of catalytic amounts of the rest of reactants. Although really catalytic PKR appeared only in the mid-1990s, developments from recent years allow us to be moderately enthusiastic. The literature gives a good deal of catalytic protocols that use different cobalt and other metal complexes. Still, a lack of scope is generally observed in these reports. In addition there are few examples of intermolecular reactions performed in catalytic conditions [21]. 

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