Liquid-liquid equilibria for toluene plus heptane+1-ethyl-3-methylimidazolium triiodide and toluene plus heptane+1-butyl-3-methylimidazolium triiodide

This study focuses on the use of an ionic liquid for extracting an aromatic hydrocarbon from a mixture of an aromatic and an aliphatic hydrocarbon. Liquid-liquid equilibrium data were collected for the toluene + heptane + 1-ethyl-3-methylimidazolium triiodide system at 45 degrees C and for the toluene + heptane + 1-butyl-3-methylimidazolium triiodide system at 35 degrees C. The nonrandom two-liquid (NRTL) physical thermodynamic model was used to correlate the experimental data. The NRTL model was found to represent the data very well. The selectivity and capacity of the ionic liquids for extracting toluene from toluene + heptane solutions were evaluated. The separation factors were found to be above 50 for low toluene compositions and nearly unity for high toluene compositions.