Investigation on the feasibility of separation process for extracting benzene from hexane/heptane by ionic liquids

Abstract

UNIFAC-Lei model has been employed for the prediction of liquid-liquid equilibrium (LLE) of ternary systems of (benzene +hexane/heptane + ionic liquids IL) for the screening of ILs which can be used as potential solvents in the extraction process of benzene from stream of hydrocarbons. The capability of UNIFAC-Lei model to predict the LLE of ternary systems is evaluated, and it is shown that UNIFAC-Lei model allowed the fast appropriate descriptions of the LLE experimental data for the systems studied in this work. The conceptual extraction process for the separation of benzene and heptane/hexane using an IL is simulated via Aspen PlusV11.0. The results showed that [EMIM][NTf₂] was the best solvent for separating benzene from aliphatic hydrocarbons and the content of benzene in the extract can be achieved 83.3 wt% for the mixture with hexane and 94.7 wt% for the mixture with heptane from the feed containing 20 wt% of benzene, respectively.