Separation of isopropyl acetate + isopropanol azeotropic mixture using ionic liquids with acetate anion as entrainers

Abstract Vapor-liquid equilibrium (VLE) data of isopropyl acetate + isopropanol, isopropyl acetate + isopropanol + 1-hexyl-3-methylimidazolium acetate ([HMIM][Ac]), isopropyl acetate + isopropanol + 1-octyl-3-methylimidazolium acetate ([OMIM][Ac]), isopropyl acetate + isopropanol +1-decyl-3-methylimidazolium acetate ([DMIM][Ac]) were obtained at 101.3 kPa with a modified Othmer still. It was found that the addition of ionic liquid produced an obvious salting-out influence on isopropyl acetate, which leads to a remarkable increase in the relative volatility of isopropyl acetate to isopropanol. The separation performance of the three ionic liquids investigated in this study decreases in the following order: [HMIM][Ac] > [OMIM][Ac] > [DMIM][Ac]. Furthermore, the VLE data could be well correlated with the nonrandom two-liquid (NRTL) model.