Isobaric Vapor–Liquid Equilibrium for the Extractive Distillation of Acetonitrile + Water Mixtures Using Dimethyl Sulfoxide at 101.3 kPa

Vapor–liquid equilibrium (VLE) data for the system formed by acetonitrile, water, and dimethyl sulfoxide (DMSO) at 101.3 kPa are measured in this paper. The data have been correlated by the classical thermodynamic models: Wilson, universal quasichemical activity coefficient (UNIQUAC), and nonrandom two-liquid (NRTL). The results indicate that all of the models can correlate the VLE data successfully and Wilson model performances the best. The effects of DMSO with various contents on the acetonitrile + water system are explored. From the results, the azeotrope is eliminated by DMSO by the means of improving their relative volatility. Hence, DMSO is an effective solvent for separating the acetonitrile + water binary azeotropic system.