Environmental impact reduction using exergy-based methods

An exergoenvironmental analysis is conducted at the component level of a system and identifies (a) the relative contribution of each component to the environmental impact associated with the entire system, and (b) options for reducing the environmental impact associated with the overall system. In an exergoenvironmental analysis a one-dimensional characterization indicator is obtained using a Life Cycle Assessment (LCA). An index (a single number) describes the overall environmental impact associated with system components and exergy carriers. It should be mentioned that the evaluation of environmental impacts would always be subjective to some degree. The paper discusses the effect of the indicator used in an exergoenvironmental analysis on the conclusions obtained from the analysis using a compression refrigeration machine as an example. The results demonstrate that the contribution of the component-related environmental impact can be neglected in the exergoenvironmental evaluation, and that only the environmental impact associated with the exergy destruction should be considered in the analysis. For the case study reported here, the conclusions extracted from the exergoenvironmental evaluation are independent of the employed environmental indicator.