Deep extractive desulfurization of diesel fuels by FeCl3/ionic liquids

The extractive desulfurization of dibenzothiophene (DBT), benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in model oil was carried out using anhydrous FeCl3 and 1-methyl-3-octylimidazolium chloride system ([Omim]Cl·2FeCl3). This new system exhibited high extractive efficiency and the sulfur removal of DBT in model oil (VIL/Voil = 1/20) could reach 99.4% at room temperature for 30 min, which was obviously superior to single [Omim]Cl as extractant (22.9%). When the [Omim]Cl·2FeCl3 was used, the S-removal of 4,6-DMDBT and BT could also be up to 99.3% and 96.2%, respectively. Moreover, the ionic liquid could be recycled five times without a significant decrease in extractive ability.