Extraction of organic compounds from Aqueous Solution Using Choline bis (trifluoromethylsulfonyl) imide

Abstract

• O-cresol, o-xylene and acetonitrile were extracted from aqueous mixtures with choline bis(trifluoromethylsulfonyl)imide. • Selectivity and distribution coefficients were calculated from LLE data. • LLE were correlated using UNIQUAC and NRTL models. • COSMO-RS thermodynamic model was applied to LLE. This work focused on the extraction of three organic compounds: o-cresol, o-xylene and acetonitrile from the aqueous solution using the ionic liquid, choline bis(trifluoromethylsulfonyl)imide. Liquid-liquid equilibria of the ternary systems: {water + organic compound + choline bis(trifluoromethylsulfonyl)imide} were measured at 298.15 K and at atmospheric pressure. The consistency and reliability of the experimental data were verified and validated by the Othmer-Tobias and Batchman correlations. The selectivity and the solute distribution ratio values calculated from experimental data indicate that [choline][Tf 2 N] is suitable for the extraction of the organic compounds from water. NRTL and UNIQUAC models were used to predict the liquid–liquid equilibrium of the investigated systems. A good agreement with the experimental data was observed with both thermodynamic models. Calculations with the COSMO-RS model show that this model is ineffective at predicting the equilibria of ternary systems containing {water + o-xylene + choline bis(trifluoromethylsulfonyl)imide}.