Environmentally benign process for removal of sulfur from liquid fuel using imidazolium based ionic liquids

A new class of green solvent, known as ionic liquids, has recently been the subject of intensive research on the extractive desulfurization of liquid fuels because of the limitation of the traditional hydrodesulfurization method in catalytically removing thiophenic sulfur compounds. The aim of study is to investigate the possible application of ionic liquids as green solvent because of their unique physical and chemical properties. In this work, four imidazolium ionic liquids, such as 1-butyl-3-methylimidazolium chloride [BMIM] Cl, 1-butyl-3-methylimidazolium bromide [BMIM] Br, 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM] BF₄ and 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM]PF₆ were commercially purchased and employed as energy efficient extractant for the desulfurization of liquid fuel. The extractive capabilities of these ILs in removing thiophene, benzothiophene, dibenzothiophene and 3- methylthiophene from model liquid fuel were investigated. The results of this work can provide meaningful insights in the understanding of the use of imidazoled ILs as green solvent for deep desulfurization of liquid fuels as it can be reused without regeneration with considerable extraction efficiency.