A Study of the Pressure Effect on the Relative Volatility of the Components in the Distillation Process of Mixtures of Different Natures

The pressure effect on the relative volatility of binary mixtures of different natures and ternary mixtures containing potential separating agents such as dimethylsulfoxide (DMSO) and butyl propionate is studied. A wide range of information is obtained based on the data on the vapor–liquid equilibrium, and effects of the pressure on the relative volatility of various nature and cause for a fixed composition of the initial mixture are determined. In the presence of intersection points of the phase-equilibrium curves in the initial binary mixture and pseudobinary mixture (in the section with a constant concentration of the third high-boiling component), the concentration simplex is divided into regions in which the values of the relative volatility decrease (increase) upon varying pressure. This fact makes it possible to improve the procedure of separation process optimization at the stage of operating pressure selection in the columns.