Separation of methanol + dimethyl carbonate azeotropic mixture using ionic liquids as entrainers

Abstract

Isobaric vapor-liquid equilibrium (VLE) data of methanol + dimethyl carbonate, methanol + dimethyl carbonate + 1-Ethyl-3-Methylimidazolium Bromide ([EMIM][Br]) and methanol + dimethyl carbonate + 1-Butyl-3-Methylimidazolium Chloride ([BMIM][Cl]) were measured by a modified Othmer still at 101.3 kPa. The two investigated ionic liquids produced significant effects on the separation of the methanol and dimethyl carbonate azeotropic system. The relative volatility of dimethyl carbonate to methanol was enhanced with the addition of ionic liquid. The two ionic liquids could both eliminate the azeotropic point as their concentration increased to a certain value, but [BMIM][Cl] showed a greater separation effect on methanol and dimethyl carbonate azeotropic system than [EMIM][Br]. Furthermore, the measured data were well correlated with the nonrandom two-liquid (NRTL) model.