ABSTRACT
Some years ago, we were teaching an advanced course in thermodynamics to process engineers of a multinational industry. Subjects included phase equilibria, the thermodynamics of mixtures, and models from molecular thermodynamics applied to industrial situations. Some participants raised the question whether some time could be spent on the subject of “the exergy analysis of processes.” At that time this was a subject with which we were less familiar because energy-related issues fell less within the scope of our activities. We fell back on a small monograph by Seader [1] and the excellent textbook by Smith et al. [2], who dedicated the last chapter of their book not so much to exergy but to the thermodynamic analysis of processes. Concepts such as ideal work, entropy production, and lost work were clearly related to the efficient use of energy in industrial processes. The two industrial examples given—one on the liquefaction of natural gas, the other on the generation of electricity in a natural gas-fired power station—lent themselves very well not only for illustrative purposes but also for applying the exergy concept and exergy flow diagrams [3,4]. The latter concepts appealed to us because of their instrumental and visual power in illustrating the fate of energy in the processes (Figure 1.1).
