Evaluation of [bmim][PF6] as an ionic solvent for the extraction of propylbenzene from aliphatic compounds

The evaluation of using 1-butyl-3-methylimidazolium hexaflurophosphate ionic liquid, [bmim][PF6], as a solvent for the extraction of propylbenzene from aliphatic compounds was studied. The (liquid + liquid) equilibrium (LLE) for two ternary systems comprising {dodecane or tetradecane + propylbenzene + [bmim][PF6]} were analysed at atmospheric pressure and two temperatures, (313 and 333) K. The consistency of the experimental tie line data was ascertained by applying the Othmer–Tobias correlation. The effect of temperature, n-alkane chain length and solvent to feed ratio upon solubility, distribution ratio, selectivity, and per cent removal of the aromatic were investigated. The experimental LLE data were correlated using the UNIQAC and NRTL models for the activity coefficient with estimation of new interaction parameters, using the simplex minimization method and a composition based objective function. The calculated results from both methods are considered satisfactory.

► [(bmim)(PF6)] was evaluated for extraction of propylbenzene from dodecane or tetradecane.
► Reliability of the experimental data was ascertained by Othmer–Tobias correlation.
► Effect of solvent to feed ratio upon separation factors were investigated.
► UNIQUAC and NRTL models correlate the experimental data satisfactorily.