FeCl3 Based Imidazolium Ionic Liquids as Novel Solvents for Extractive-Oxidative Desulfurization of Liquid Fuels

摘要

FeCl3 based imidazolium ionic liquids were synthesized and employed as novel solvents in extractive desulfurization for removal of dibenzothiophene, thiophene, benzothiophene, 3-methylthiophene, and 4,6-dimethyldibenzothiophene in model fuel. FeCl3 based ionic liquids such as 1-butyl-3-methylimidazolium chloride iron chloride [C4MIM]Cl/FeCl3, 1-octyl-3-methylimidazolium chloride iron chloride, didecyldimethyl ammonium chloride iron chloride, ammonium tributyl-methyl chloride iron chloride, and trioctyl-methyl ammonium chloride iron chloride were synthesized and screened for extractive desulfurization of liquid fuel. Due to the redox properties of [C4MIM]Cl/FeCl3 with addition of hydrogen peroxide, dibenzothiophene removal can reach 92 % under mild reaction conditions, which is not only higher than simple extraction with ionic liquids, but better than other FeCl3 based ionic liquids under the same reaction conditions. The spent [C4MIM]Cl/FeCl3 can be recycled without regeneration for five times with only a slight decrease in activity. Also, desulfurization and multistage extraction of real fuels with [C4MIM]Cl/FeCl3 were studied. The data and results provided in the present paper provide significant insights into FeCl3 based imidazolium ionic liquids as novel solvents for desulfurization of liquid fuels.