Wiley Kirk-Othmer Encyclopedia of Chemical Technology, Volume 9: 19 (Kirk 5e Print Continuation Series)

The Kirk-Othmer Encyclopedia of Chemical Technology presents a wide scope of articles on chemical substances, their manufacturing and uses, industrial processes, unit operations in chemical engineering, and on fundamentals and scientific subjects related to the field. The Fifth Edition of the encyclopedia is built on the solid foundation of the previous editions and also reflects advances of the 21st century. About the Author Kirk-Othmer is the editor of Kirk-Othmer Encyclopedia of Chemical Technology, Volume 9, 5th Edition, published by Wiley. Excerpt. © Reprinted by permission. All rights reserved. Kirk-Othmer Encyclopedia of Chemical Technology By Arza Seidel Wiley-Interscience Copyright © 2004 Arza SeidelAll right reserved. ISBN: 9780471485148 Chapter One GREEN CHEMISTRY 1. Introduction Green chemistry and green engineering describe the efforts of chemists and engineers to develop processes and products that prevent pollution and are inherently safe for humans and the environment. Implementing green chemistry and engineering will improve the quality of the environment for present and future generations. Manufacturing a chemical product requires a synthetic pathway as well as a safe and efficient chemical manufacturing strategy. Thus, both chemistry and engineering are required to achieve true source reduction. Green chemistry is a term first proposed by Paul Anastas, formerly of the U.S. Environmental Protection Agency (EPA). Definitions of green chemistry typically include aspects of basic chemistry and applied engineering practice. For example, Anastas and Warner define green chemistry as follows: "Green chemistry is the use of chemical principles and methodologies for source reduction. Green chemistry incorporates pollution prevention in the manufacture of chemicals, and promotes pollution prevention and industrial ecology." A slightly more succinct definition is: "The invention, design, and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances." Another description of green chemistry is by Sheldon: "Green chemistry efficiently utilizes (preferably renewable) raw materials, eliminates waste, and avoids the use of toxic and/or hazardous reagents and solvents in the manufacture and application of chemical products." The chemical engineering profession also promotes the concept of source reduction. "Green Engineering" has been defined as follows: "Green Engineering is the design, commercialization, and use of processes and products that are feasible and economical, while minimizing both risk to human health and the environment, and generation of pollution at the source." Green chemistry, by definition, addresses source reduction, which is the highest priority activity in the listings of pollution prevention priorities given by Mulholland and Dyer and Allen and Rosselot. Green chemistry is the science and technology of preventing wastes before they are generated, and includes every consideration from feedstock origins to end of product life. The term "sustainable chemistry" is sometimes used with essentially the same meaning. Subsequent sections of this article will provide additional focus to the scope of green chemistry and engineering. First, a historical context is presented. Chemical manufacturers have invested substantial capital and effort on environmental matters for at least the past 30 years. Initially, the driving forces were government and community demand to control emissions of pollutants to the air, water, and land, and to clean up contaminated sites. The U.S. EPA has long practiced a command-and-control approach, assuming that pollution is inevitable and that the main effort of industry is to control and treat pollutants. This has led to the development of many downstream or end of pipe processes for pollution treatment, abatement, and control. To understand the historical r