Liquid–liquid equilibrium data for the systems {LTTM + benzene + hexane} and {LTTM + ethyl acetate + hexane} at different temperatures and atmospheric pressure

Low transition temperature mixtures (LTTMs), which are ionic liquid analogues, are evaluated in this work as extractant solvents for the separation of benzene from hexane (aromatic/aliphatic mixture) and ethyl acetate from hexane, which are both azeotropic systems. Experimental data for liquid–liquid equilibria were obtained at 25, 35 and 45 °C. LTTMs showed much higher selectivities but lower distribution ratios compared to the solvent that is currently used in industry. The phase diagrams of the ternary systems composed of LTTM + benzene + hexane and LTTM + ethyl acetate + hexane are shown and the experimental data were correlated by using the UNIQUAC model. LTTMs are compared with other reported ionic liquids (ILs) and deep eutectic solvents (DES) as well as sulfolane in order to evaluate their ability to separate azeotropic mixtures through liquid–liquid extraction (LLE).

Graphical abstractThe ability of choline-based low transition temperature mixtures (LTTMs) to separate benzene/hexane and ethyl acetate/hexane is evaluated in this research. Its effect on these azeotropic mixtures is compared to the effect of sulfolane and other LTTMs reported in literature. LLE data are presented and discussed in this paper.Figure optionsDownload full-size imageDownload as PowerPoint slide