Salt-Containing Extractive Distillation of 1-Propanol/Water System 1. Prediction of Salt Effect on Vapor Liquid Equilibrium

摘要

This paper has studied the vapor-liquid equilibrium (VLE) for the salt-containing extractive distillation of the 1-propanol/water system. Binary VLE data were measured for the systems of 1-propanol (1)/KAc (4), ethanediol (3)/KAc (4), and 1-propanol (1)/ethanediol (3), with the VLE data correlated with the NRTL model in order to obtain the model parameters of these binary systems. The binary VLE data cited in technical literature were correlated to obtain the model parameters for other binary systems. VLE data of ternary and quaternary systems predicted by the NRTL model agreed well with the literature data. The influence of KAc, ethanediol, and the KAc/ethanediol mixture on volatility between 1-propanol and water was investigated respectively. Test results showed that the above-mentioned materials (KAc, ethanediol) and their mixture (KAc and ethanediol) have different influence on the volatility. When x3=0.5, and x4=0.05, the azeotropic point can be eliminated. The NRTL model method of salt-containing VLE is simple and effective for the prediction of the system's VLE data.