A comparative study of pure ionic liquids and their mixtures as potential mass agents in the separation of hydrocarbons

Abstract

In this work, a study about the use of pure ionic liquids (ILs) and mixtures thereof as mass agents in the selective separation of n-heptane and toluene was carried out in order to compare the behavior of the ILs mixtures and the corresponding pure ILs. For that, the isothermal vapor-liquid equilibrium (VLE) data for {n-heptane+toluene+1-ethyl-3-methylimidazolium tricyanomethanide ([EMim][TCM])+1-ethyl-3-methylimidazolium dicyanamide ([EMim][DCA])} and {n-heptane+toluene+[EMim][TCM]} mixtures were experimentally determined at several temperatures over the whole composition range within miscibility region. The experimental VLE data obtained in this work were compared with those previously published for {n-heptane+toluene+[EMim][DCA]}. Finally, the experimental VLE data, which were obtained using a static headspace gas chromatograph (HS-GC), were adequately correlated using the non-random two liquids (NRTL) thermodynamic model.The obtained results confirm that ILs have an important effect on the VLE of systems containing n-heptane and toluene, which shows that these ionic solvents could be a promising alternative to carry out a selective separation of these hydrocarbons.