Deep eutectic solvent as a possible entrainer for industrial separation problems: Pre-screening tool for solvent selection

Abstract

Deep eutectic solvents, as a new type of nature-welcoming solvents, have shown a great interest in different areas of science and in solvent extraction for industrial separation processes. In this present study, the infinite dilution activity coefficients γ13∞, have been measured for 31 volatile organic solvents (alkanes, alkenes, alkynes, aromatics, cycloalkanes, cycloalkenes, alcohols, ketones, and thiophene) in the deep eutectic solvent (1-ethyl-1-methylpyrrolidinium bromide + glycerol) prepared at (1:2 molar ratio) measured at temperature ranging from T = (313.15 to 343.15) K and at atmospheric pressure using gas liquid chromatography coupled with thermal conductivity detector (GC-TCD). The values of the partial molar excess enthalpies (ΔH1E,∞), entropies (TrefΔS1E,∞), and Gibbs free energy (ΔG1E,∞) at infinite dilution were calculated from the experimental data of γ13∞ attained over the temperature range mentioned above. Selectivities and capacities for two separation problems (cyclohexane/benzene and acetone/ethanol) were calculated fromγ13∞ and compared to the other investigated DESs, ILs as well as the currently used traditional solvents found from the literature. Furthermore, the selectivity and capacity results proved that the examined DES cannot be utilized in separation of (acetone/ethanol) but can be utilized for cyclohexane/benzene separation.