Study on the separation of propylbenzene from alkanes using two methylsulfate-based ionic liquids at (313 and 333) K

• [(mmim)(CH3SO4)], [(emim)(CH3SO4)] were evaluated for extraction of propylbenzene from alkanes.
• Reliability of the experimental data was ascertained by Othmer–Tobias correlation.
• Effect of operation conditions upon separation factors were investigated.
• UNIQUAC and NRTL models correlate the experimental data satisfactorily.

The separation of propylbenzene from dodecane or tetradecane using different ionic liquids (ILs) based on the methylsulfate anion (CH3SO4−) was studied at two temperatures (313 and 333) K and atmospheric pressure. The ionic liquids, 1, 3-dimethylimidazolium methylsulfate [(mmim)(CH3SO4)] and 1-ethyl-3-methylimidazolium methylsulfate [(emim)(CH3SO4)], were evaluated as solvents for the extraction process. Four ternary systems were formed by {dodecane or tetradecane + propylbenzene + [(mmim)(CH3SO4)] or [(emim)(CH3SO4)]}. The degree of quality of the experimental data was ascertained using the Othmer–Tobias correlation. A comparison of the phase behaviour of the systems studied has allowed us to investigate the effect of ILs cation, alkane chain length, temperature and solvent-to-feed ratio upon solubility, percent aromatic removal, distribution ratio, and selectivity. Finally, the experimental LLE data was correlated using the UNIQUAC and the NRTL models.