The Separation of Aromatic Hydrocarbons Through a Supported Ionic Liquid Membrane

Ionic liquids can be considered as environmentally friendly solvents because of their low vapor pressures. Room-temperature ionic liquids are used as a supported liquid membrane for separation of aromatic from aliphatic. Aromatic hydrocarbons, benzene, toluene, ethylbenzene, and p-xylene are successfully transported through the polypropylene supported ionic liquid membrane based on 1-methyl-3-octyl imidazolium chloride. The separation performances, represented by the percentage extraction and separation factor, are analyzed systematically by varying the operating parameters: the contact time, membrane phase composition, and initial feed phase concentration. The mathematical models that have been used to simulate experimental data have been discussed. The scanning electron microscope combined with energy-dispersive X-ray analysis of membranes after continuous operation shows that the membrane phases are still retained within the membrane pores and only small losses of the membrane phase initially located on the surface are observed.