The investigation of the infinite dilution activity coefficients for molecular compounds in 1-(3-hydroxypropyl)-3-methyl-imidazolium thiocyanate

Abstract

Measurements of infinite dilution activity coefficients of 46 organic solutes including alkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, ethers, ketones, pyridine, thiophene, acetonitrile, and 1-nitropropane in ionic liquids (IL), 1-(3-hydroxypropyl)-3-methyl-imidazolium thiocyanate (abbreviated as [C1C3OHIM][SCN]) are reported in the temperature range from T = (318.15 to 358.15) K. Based on the experimental data, the infinite dilution capacity and selectivity of the studied IL are presented to evaluate the effectiveness of using it as an extractant in the separation of aliphatic from aromatic hydrocarbons and sulfur compounds from alkanes. Obtained selectivity and capacity values for different separation processes are compared with the literature data for other ionic liquids. From the temperature – dependence of the infinite dilution activity coefficient, the partial molar excess Gibbs energy, ΔG1E,∞, enthalpyΔH1E,∞ and entropy term TrefΔS1E,∞ at infinite dilution were calculated and discussed.