Measurement and correlation of vapor–liquid equilibria and excess enthalpies of binary systems containing ionic liquids and hydrocarbons

Vapor–liquid equilibria (VLE) and excess enthalpies (HE) have been measured for the hydrocarbons hexane, 1-hexene, cyclohexane, cyclohexene, benzene and toluene with the ionic liquids 1-metyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [MMIM]+ [(CF3SO2)2N]−, 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [EMIM]+ [(CF3SO2)2N]−, 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [BMIM]+ [(CF3SO2)2N]−, 1-metyl-3-methyl-imidazolium ethylsulfate [EMIM]+ [C2H5OSO3]− and pyridiniumethoxyethylsulfate [C5H5NH]+ [C2H5OC2H4OSO3]− at 353.15 K, 303.15 K and 333.15 K, respectively. The experimental VLE and HE data were correlated together with available activity coefficients at infinite dilution γi∞ using the NRTL and UNIQUAC models and the relative van der Waals volume and surface area parameters r and q estimated by the Bondi method. The overall average errors using NRTL and UNIQUAC model are 4.6% and 4.8% for VLE, 1.7% and 1.9% for γi∞ and 3.6% and 3.2% for HE.