Experimental study on liquid – liquid equilibria of ionic liquids + alkane + ethyl benzene or p-xylene at 298.15 K

• Extraction of ethyl benzene and p-xylene from alkane with ionic liquid was studied.
• The ionic liquids [Bmim][NO3] and [Omim][NO3] were used.
• The selectivities values for the systems with [Bmim][NO3] are higher than [Omim][NO3].
• The effect of alkyl chain length of ionic liquids on the aromatic selectivity is studied.
• The NRTL model was used for correlation of the experimental data.

New experimental data for the ternary systems of 1-butyl 3- methylimidazolium nitrate ([Bmim][NO3]) or 1-methyl 3-octylimidazolium nitrate ([Omim][NO3]) + alkane (hexane or heptane or octane) + aromatic (ethyl benzene or p-xylene) at 298.15 K and atmospheric pressure are reported. The aromatic selectivity and distribution coefficient are calculated from experimental data. The effect of alkyl chain length of ionic liquids as well as alkane on the aromatic selectivity is studied. The selectivity values for the studied systems with [Bmim][NO3] is more than [Omim][NO3]. The reliability of the experimental data is tested with the Othmer- Tobias and Hand equations. The NRTL thermodynamic model was successfully used to correlate the experimental data.