Isobaric vapor-liquid equilibria for extractive distillation of 1-propanol + water mixture using thiocyanate-based ionic liquids

•Thiocyanate-based ionic liquids are proposed to dehydrate 1-propanol by an extractive distillation.•Binary VLE data of [emim][SCN] and [bmim][SCN] with 1-propanol or water are obtained at 101 kPa.•Ternary VLE data of 1-propanol + water + [emim][SCN] or + [bmim][SCN] are obtained at 101 kPa.•NRTL, electrolyte NRTL and UNIQUAC model parameters are obtained after data correlation.

This paper presents vapor-liquid equilibrium (VLE) data at 101.3 kPa for the ternary systems 1-propanol + water + 1-ethyl-3-methylimidazolium thiocyanate [emim][SCN] and 1-propanol + water + 1-butyl-3-methylimidazolium thiocyanate [bmim][SCN] and their constituents binary systems. The experimental data obtained were correlated using the NRTL, eNRTL and UNIQUAC models. It was found that the addition of these ionic liquids enhance the relative volatility of 1-propanol to water, and the separation ability follows the order of [emim][SCN] > [bmim][SCN]. The results obtained were compared with the VLE data of the system containing this azeotropic mixtures with different imidazolium-based ionic liquids reported in the literature.