Chemical exergy of ideal and non-ideal gas mixtures and liquid solutions with applications

Abstract

Exergy or availability, although not a recent concept, is receiving extensive coverage in scientific publications due to its vast applications in different scientific and engineering fields. Exergy of a system consists of two parts: thermo-mechanical exergy and chemical exergy. While thermo-mechanical exergy of systems is covered to a certain extent in modern undergraduate textbooks on engineering thermodynamics, chemical exergy is mentioned only briefly. In particular, the theoretical and conceptual developments related to chemical exergy are not covered in any detail. The focus of this article is the chemical exergy of materials. Special attention is given to the theoretical treatment of non-ideal gas mixtures and liquid solutions. The equations necessary to estimate the chemical exergy of ideal and non-ideal mixtures and solutions are developed from the fundamental concepts. Where necessary, numerical examples are given to illustrate the concepts for the benefit of the students. Finally, a practical problem dealing with the furnace/boiler unit of a practical steam power plant is solved using the concepts of chemical exergy and exergy analysis. As the material presented in this article involves advanced level concepts in thermodynamics, it is most suitable for the second, advanced level, course in engineering thermodynamics in third year, after the students have completed a full one-term course on introductory thermodynamics in their second year.