| Abstract: | Recently, significant attention has been directed towards the use of exergy analysis in the assessment of thermal and other industrial processes and their environmental impacts since exergy analysis is an effective tool both for achieving efficient energy utilization with minimum (or zero) environmental impact and for understanding environmental issues. In this study, the concepts of exergy analysis and the linkages between exergy and environmental impact are discussed, and several issues regarding the exergies of waste emissions are addressed. Exergy is a measure of the degree of disequilibrium between a substance and its environment. The relations between several measures of environmental impact potential and exergy are investigated by comparing current methods used to assess the environmental impact potential of waste emissions and the exergy associated with those emissions. A case study is presented, to highlight the information revealed using exergy, in which the measures of environmental impact potential considered are the Ontario Ministry of Environment's schedule of industrial air emission limits, and two methods of assessing the environmental costs for air emissions resulting from the combustion of three common fossil fuels: coal, oil and natural gas. Copyright © 1999 John Wiley & Sons, Ltd. |
