Interpretation of the exergy equation for steady-flow processes

We define and discuss the terms in exergy equations, with particular reference to the role of chemical terms in the exergy loss for steady-flow processes. Although there is a chemical contribution to exergy, exergy losses of steady-flow processes may be calculated by using a simple expression for the specific exergy, namely, b = h − T*s. No restrictions are found in the material flows involved. The necessity of prescribing a standard chemical reference environment is considered and rejected. Instead, a sign convention for material flows is proposed. Finally, some results of Brzustowski's calculations are reviewed and discussed.