화학공학소재연구정보센터
Journal of Chemical Thermodynamics, Vol.77, 63-70, 2014
Thermodynamics and activity coefficients at infinite dilution for organic solutes, water and diols in the ionic liquid choline bis(trifluoromethylsulfonyl)imide
The activity coefficients at infinite dilution, gamma(infinity)(13), for 63 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, ethers, ketones, esters, aldehyde, acetonitrile, pyridine and 1-nitropropane and 6 diols in the ionic liquid (IL) choline bis(trifluoromethylsulfonyl)imide, [N-1112OH][NTf2] were determined by (gas + liquid) chromatography at six temperatures in range of (318.15 to 368.15) K and at three temperatures for diols in the range of (388.15 to 418.15) K. The thermodynamic functions at infinite dilution as partial molar excess Gibbs free energy, Delta G(1)(E,infinity), enthalpy Delta H-1(E,infinity), and entropy term Tref Delta S1E,infinity were calculated from the experimental gamma(infinity)(13) values obtained over the temperature range. The density of [N-1112OH][NTf2] was measured within temperature range (313.15 to 353.15) K. The (gas + liquid) partition coefficient K-L was calculated for all solutes. The values of selectivity and capacity for a few separation problems as hexane/benzene, cyclohexane/benzene, heptane/thiophene at T = 328.15 K were calculated from gamma(infinity)(13) and compared to literature values for similar ionic liquids, N-methyl-2-pyrrolidinone (NMP), and sulfolane. In comparison with the former measured ammonium-based ILs and the morpholinium-based ILs, the [N-1112OH][NTf2] shows average selectivity for the separation of aromatic hydrocarbons, or sulfur compound from aliphatic hydrocarbons, and very high selectivity for pyridine/heptane separation. New data show that [N-1112OH][NTf2] IL may be proposed as an alternative solvent for the separation of sulfur or nitrogen compounds from alkanes. (C) 2014 Elsevier Ltd. All rights reserved.