Chapter 1 - Thermodynamic fundamentals

Abstract

This chapter provides the thermodynamic fundamentals closely related with special distillation processes. Vapor–liquid phase equilibrium as the most applied and calculable form of phase equilibrium plays a major role in special distillation processes. Salt effect is commonly utilized in special distillation process. There are many theories about salt effect such as the electrostatic theory of Debye–McAulay in dilute electrolyte solutions, internal pressure theory of McDevit–Long, salt effect nature of Huangziqing, electrolyte solutions theory of Pitzer, and scaled particle theory. The aim of non-equilibrium thermodynamics analysis for special distillation processes is to interpret in what condition and/or why the process can take place, so as to substantially understand the essence and find the theoretical judging rule. The most difference between equilibrium thermodynamics and non-equilibrium thermodynamics is that mass transfer should be considered in the latter. Heat transfer is indispensable to establish the energy balance equation in a non-equilibrium thermodynamics. To determine the component heat transfer coefficient, the simplest way is to use the analogous expressions among momentum, heat and mass transfer, such as Reynolds analogy, Chilton–Colbum analogy, and Prandtl analogy.