Direct extractive desulfurization of sulfur compounds by [EMIM]Br-FeCl_2

Ionic liquid [EMIM]Br-FeCl2 is used in extraction desulfurization.The desulfurization efficiency on thiophene(TS),benzothiophene(BT),dibenzothiophene(DBT) in model oil and gasoline is investigated.The experimental results show that when the extraction temperature and time are 40℃ and 4 h,respectively,the removal rate of TS at 2∶ 1 mass ratio of [EMIM]Br-FeCl2 to oil is 25.6%.When the mass ratio of [EMIM]Br-FeCl2 to oil is 2∶ 5,the desulfurization efficiencies of BT and DBT reached to 72.4% and 79.9% respectively.As the optimum conditions of extracting TS are used on FCC gasoline,the single-pass desulfurization rate ranges from 50.3% to 54.5%,and the rate ranges from 89.3% to 91.3% after five times of extraction.The ionic liquid can be recycled more than ten times without significant decrease in activity.