Separation of azeotropic mixture isopropyl alcohol + ethyl acetate by extractive distillation: Vapor-liquid equilibrium measurements and interaction exploration

Abstract

Isopropyl alcohol and ethyl acetate can be used to produce degradable and renewable fuel. Since isopropyl alcohol + ethyl acetate can form an azeotropic mixture, it is a tough task to separate the binary mixture by general distillation. In this work, extractive distillation process with N, N-dimethylformamide and dimethyl sulfoxide as entrainers was adopted to separate this azeotrope. The binary and ternary vapor-liquid equilibrium data for (isopropyl alcohol + N, N-dimethylformamide), (ethyl acetate + dimethyl sulfoxide), (isopropyl alcohol + ethyl acetate + N, N-dimethylformamide) and (isopropyl alcohol + ethyl acetate + dimethyl sulfoxide) were determined under 101.3 kPa. Meanwhile, the interaction energies between the molecules were calculated to provide the theoretical insight into the separation of the azeotrope of (EA + IPA) by the entrainers. In addition, the NRTL, UNIQUAC and Wilson models were used to fit the determined binary VLE data. The ternary VLE data for (isopropyl alcohol + ethyl acetate + N, N-dimethylformamide) and (isopropyl alcohol + ethyl acetate + dimethyl sulfoxide) were predicted using the NRTL, UNIQUAC and Wilson models with the parameters regressed from the experimental data.