Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The activity coefficients at infinite dilution, c1 13, for 53 different solutes including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, ethers, ketones, thiophene, acetonitrile, pyridine, 1-nitropropane and water in the ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide, [COC2N1,2,2][NTf2] were determined using inverse gas-liquid chromatography. The experiment has been performed at five temperatures over the range of (318.15 to 358.15) K. From experimental results, the partial molar excess Gibbs energy, DGE;1 1 , enthalpy DHE;1 1 and entropy term TrefDSE;1 1 at infinite dilution were calculated. Additionally, the gas-liquid partition coefficients of the solutes, KL were calculated. The value of selectivity, S1 12 and capacity, k1 2 at infinite dilution for hexane/benzene, cyclohexane/benzene, heptane/thiophene and heptane/pyridine separation processes were calculated directly from c1 13. These parameters are compared to literature values of S1 12 and k1 2 for other ionic liquids and NMP, or sulfolane solvents commercially used on an industrial scale in separation processes. Moreover, physicochemical properties of pure ILs that is: density, viscosity and surface tension have been determined as a function of temperature and basic thermal properties of pure [COC2N1,2,2][NTf2] were measured using DSC technique.