Phase equilibria study of the binary systems ( N-butyl-3-methylpyridinium tosylate ionic liquid + an alcohol)

Abstract

Isothermal (vapour + liquid) equilibrium data, (VLE) have been measured by an ebulliometric method for the binary mixtures of ionic liquid (IL) { N-butyl-4-methylpyridinium tosylate ( p-toluenesulfonate) [BMPy][TOS] + ethanol, 1-propanol, and 1-butanol} at T = 373.15 K over the pressure range from p = 0 kPa to p = 110 kPa. (Solid + liquid) phase equilibria (SLE) for the binary systems: ionic liquid (IL) { N-butyl-4-methylpyridinium tosylate ( p-toluenesulfonate) [BMPy][TOS] + ethanol and 1-propanol} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (320 to 390) K. For the binary systems containing alcohol, it was noticed that with increasing chain length of alcohol vapour pressure of the mixture and the solubility of the IL decreases. Well-known Wilson, NRTL, and UNIQUAC equations have been used to correlate simultaneously the experimental VLE and SLE data sets with the same parameters. The excess molar Gibbs free energy, G E function in general was negative in all systems at high temperature (VLE) and positive at low temperatures (SLE).