Isobaric vapor–liquid equilibrium for methyl acetate + methanol with double salt ionic liquid [EMIM][Cl]0.5[DCA]0.5 as entrainer at 101.3kPa

Abstract The double salt ionic liquid (DSIL) [EMIM][Cl]0.5[DCA]0.5, which was made by mixing 1-ethyl-3-methylimidazolium chloride ([EMIM][Cl]) and 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]), was used for the separation of the methyl acetate + methanol azeotropic mixture. Isobaric vapor−liquid equilibrium (VLE) data for the ternary system of methyl acetate (1) + methanol (2) + [EMIM][Cl]0.5[DCA]0.5 (3) were measured at 101.3 kPa. The DSIL [EMIM][Cl]0.5[DCA]0.5 produced significant salting-out effect to methyl acetate and was able to break the azeotropic point of methyl acetate + methanol at low concentration of DSIL. The Non-Random Two-Liquid (NRTL) activity coefficient model was adopted to correlate the vapor−liquid equilibrium (VLE) data using three different objective functions, and the parameters of NRTL model were obtained based on the best objective function. Isobaric vapor−liquid equilibrium (VLE) data for the ternary systems of methyl acetate (1) + methanol (2) + [EMIM][Cl] (3) and methyl acetate (1) + methanol (2) + [EMIM][DCA] (3) were also measured at 101.3 kPa. The separation effects of DSIL [EMIM][Cl]0.5[DCA]0.5 were compared with the single ionic liquids [EMIM][Cl] and [EMIM][DCA].