Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Deep eutectic solvents (DESs) are considered as the new ionic liquids (ILs) analogues that have emerged as potential alternative 'green' solvents, for a diversity applications. In this study, a type III DES based on ammonium salt was investigated as an alternative solvent to currently employed conventional organic solvents in separation processes. The activity coefficients at infinite dilution, (gamma^inf) for 19 organic solutes in the tetramethylammonium chloride + ethylene glycol DES were measured by the gas-liquid chromatography (GLC) method at four temperatures in the range from (313.15 to 343.15) K. The experimental measurements were undertaken with an overall uncertainty of +- 5.40 %. The effect of the structure of the solutes on (gamma^inf) was also investigated. For all investigated solutes, Gibbs Helmholtz relationship was utilised to derive partial molar excess enthalpy values at infinite dilution (deltaH^(E,inf)) from experimental limiting activity coefficient data . From selectivity (S^inf_ij) and capacity (k^inf_j) values at infinte dilution, it was concluded that the investigated DES has the potential to replace a number of industrial solvents for the separation of various industrial mixtures.