Separation of isopropyl ether and acetone using ionic liquids based on quantum chemistry calculation and liquid–liquid equilibrium

Selecting green and efficient extractive solvents are the inevitable requirement of sustainable development. Ionic liquids as green solvents are widely used in the separation of organic substance. In this manuscript, ionic liquids are used as extractive solvents to separate isopropyl ether-acetone system. The selected ionic liquids are 1-ethyl-3-methylimidazole dinitrile amine [EMIM][DCA], n-butyl-3-methylimidazole trifluoromethane sulfonate [BMIM][OTF], 1-ethyl-3-methylimidazole trifluoromethane sulfonate [EMIM][OTF]. Firstly, the relation between H-bonding donor and H-bonding acceptor is description by COSMO-SAC model based on the extraction mechanism. After that the experiments of liquid–liquid equilibrium are conducted at T = 298.15 K and P = 101.325 kPa, and the liquid–liquid equilibrium data are correlated by NRTL model. The results indicate that the model has a good correlation with the experimental results. Finally, the extraction mechanism is discussed at micro scale. The H-bonding interaction between ionic liquids and acetone, including total charge density, bond length, deformation charge density and interaction energy, is determined by quantum chemistry calculation. The quantum chemical calculation and experimental process provide theoretical guidance for the highly efficient separation of acetone - isopropyl ether binary system.