Study of extraction-oxidation desulfurization of model oil by acidic ionic liquid

Acidic ionic liquid N-carboxymethylpyridine hydrosulphate ([CH2COOHPy]HSO4) as the extractant and catalyst and hydrogen peroxide as the oxidant were used for the extraction-oxidation desulphurization of model oil (dibenzothiophene dissolved in n-octane). The effects of the amounts of hydrogen peroxide and ionic liquid, reaction temperature, and reaction time on the sulfur removal were investigated. The results show that when the molar ratio of sulfur to H2O2 is 1: 6, volume ratio of ionic liquid to model oil is 0.6:10, and reaction time is 40 min at 50°C, the sulfur removal of model oil can reach 99.7%. The ionic liquid can be recycled 5 times without obvious decrease in the sulfur removal.