Criteria for Selection and/or Design of Green Solvents

Abstract

Abstract Converting waste into products, as Holtapple does, is one way to enhance “greenness.” Another approach is “source prevention,” which Roger L. Garrett believes is the ultimate goal in the field of green chemistry. If you want to avoid the toxic effects of a substance, he said, “don’t generate it in the first place” (Wilkinson, 1997). The use of solvents in the chemical industry and in the chemical-related industries is ubiquitous. Beyond “chemical industries,” solvent use has become an integral part of life in the twenty-first century. In 1991, the production of the 25 most commonly used solvents was more than 26 million tons per year. According to EPCRA section 313 data, of the chemicals and chemical categories tracked by the program in 1994, five of the top 10 chemicals released or disposed of were solvents, and included methanol, toluene, xylene, methyl ethyl ketone, and dichloromethane. The total quantity of these chemicals released or disposed of was over 687 million pounds, which accounts for 27% of the total quantity of TRI-listed chemicals released and disposed of in that year (Sullivan, 1997). Because solvents are required in such high volumes compared to all other materials used in a synthetic transformation, hazards associated with solvents and safety issues associated with their use have always been a consideration in the development and selection of solvents. Some of the earliest and most obvious hazards, that if solvents were found to possess would cause them to be selected against, include properties such as high flammability or explosivity.