Radiation chemistry: The basis for an inherently green process technology

In using ionizing radiation generated from electron beam accelerators or in using photoinitiated reactions started by high intensity ultraviolet light, industry has eliminated the need for volatile organic compounds from coatings, inks, and adhesives. Such processes have also been found to be energy efficient and to minimize wastes, conserving both energy and materials. Large-scale process studies have indicated that ionizing radiation can also be used to precipitate sulfur dioxide and nitrous oxides from stack gases and to dehydrohalogenate toxic halocarbons found in wastewater and in soils. While recognized for its environmental benefits by organizations such as the International Atomic Energy Agency, the United States Environmental Protection Agency, and the National Science Foundation, industrial acceptance of such inherently green processes based on radiation chemistry has been slowed by a tendency in U.S. industry to conserve capital in plants and equipment rather than to make fundamental changes in process technology. Case studies are presented to illustrate the mechanisms involved and the resultant environmental and economic benefits.