Separation of isopropyl alcohol + isopropyl acetate azeotropic mixture: Selection of ionic liquids as entrainers and vapor–liquid equilibrium validation

Abstract

Based on the COSMO-SAC model, 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium p -toluenesulfonate were selected from 30 ILs as entrainers to investigate the separation of the isopropyl alcohol + isopropyl acetate azeotrope. Two screening indicators, σ -profile and infinite dilution selectivity ( S ∞ ), were adopted as the basis. The isobaric vapor–liquid equilibrium experiments for isopropyl alcohol + isopropyl acetate binary system and isopropyl alcohol + isopropyl acetate + confirmed ILs ternary systems were performed at the pressure of atmospheric pressure. The experimental measurement demonstrated that the adopt ILs enhanced the relative volatility of the above alcohol-ester azeotrope, leading to the elimination of the azeotropic point with a certain amount ILs. Meanwhile, the thermodynamic correlation for two systems containing ILs was explored with the NRTL model, which also reflects the extensive applicability of that by comparing the deviation between experimental and calculated data. And its binary interaction parameters were regressed, which can provide a basis for its simulation process.