Isopropanol dehydration via extractive distillation using low transition temperature mixtures as entrainers

•Low transition temperature mixtures (LTTMs) were used for the (isopropanol+water) separation.•(Vapor+liquid) equilibrium (VLE) data of pseudo-binary and pseudo-ternary systems were measured.•The VLE data were successfully correlated using the NRTL model.•(Glycolic acid+choline chloride) (molar ratio=3:1) showed the largest azeotrope displacement. Low transition temperature mixtures (LTTMs), also known as deep eutectic solvents, show properties that make them suitable as entrainers for extractive distillation. Two different low transition temperature mixtures were considered as potential entrainers for the extractive distillation of the azeotropic mixture (isopropanol+water). (Lactic acid+choline chloride) (2:1) and (glycolic acid+choline chloride) (3:1) were selected for this work. (Vapor+liquid) equilibrium measurements of the pseudo-binary systems (isopropanol+LTTM) and (water+LTTM) were measured at different concentrations of LTTM in a pressure range of 10 to 100kPa. (Vapor+liquid) equilibrium data of the pseudo-ternary system (isopropanol+water+LTTM) were also measured at constant pressure (100kPa) and constant LTTM molar fraction of 0.05 and 0.1. It was found that these LTTMs cannot break the azeotrope at those concentrations. However, the azeotrope was displaced to a much higher isopropanol concentration. The NRTL model was successfully applied to fit the experimental data.