Oxidative Desulfurization of Dibenzothiophene Catalyzed by VO(acac)2 in Ionic Liquids at Room Temperature

A simple extraction and catalytic oxidative desulfurization (ECODS) system composed of VO(acac)(2), 30% H2O2, and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) has been found to be suitable for the deep removal of dibenzothiophene (DBT) in model oil at room temperature. The optimal conditions were as follows: [n(H2O2)/n(DBT)/n(catalyst) = 100:20:1], model oil = 5 mL, ionic liquid [IL] = 1 mL, T = 30 degrees C, t = 2 hr. With the ECODS system, the sulfur removal of DBT could reach 99.6%, which was superior to that of the simple extraction with IL (15.6%) or oxidation without catalyst (17.1%). The IL could be recycled five times without a significant decrease in activity.