Extraction of benzene from heptane with pyridinium based ionic liquid at (298.15, 308.15 and 318.15) K

• Extraction of benzene from heptane with pyridinium based ionic liquid was studied.
• The ionic liquids [BPy][NO3] and [HPy][NO3] were used.
• The effect of temperature on extraction of benzene from heptane is investigated.
• The effect of alkyl chain length of ionic liquids on the benzene selectivity is studied.
• The experimental data are correlated with the NRTL model.

In this research, the liquid–liquid equilibrium data (LLE) for the ternary systems of {N-butylpyridinium nitrate, [BPy][NO3] + heptane + benzene} and {N-hexylpyridinium nitrate, [HPy][NO3] + heptane + benzene} at the temperatures (298.15, 308.15 and 318.15) K and atmospheric pressure were determined. The solute distribution ratio and selectivity from the LLE data were calculated. The benzene selectivity for systems with [BPy][NO3] is higher than [HPy][NO3] and [BPy][NO3] is an appropriate solvent for benzene extraction. Besides, the influence of the temperature on benzene distribution ratio and selectivity of benzene was also investigated. Finally, the experimental data were correlated with the NRTL thermodynamic model.