Deep oxidative desulfurization of model fuels with sulfonated polystyrene as catalyst in ionic liquids

Abstract

A new, high-efficiency catalyzed oxidative desulfurization system is developed. In this system, sulfonated polystyrene spheres (SPS), which are prepared through sulfonating polystyrene resin spheres (PS) at 30 °C, ionic liquids and H2O2 are employed as catalyst, extractant and oxidant, respectively. SPS are characterized with different methods and results show that SPS have hierarchical porous structure, high specific surface area (580 m2/g) and acid content (524 mmol/g). SPS show excellent catalytic property with ionic liquids and 99.8% dibenzothiophene (DBT) in model oil can be removed at 60 °C in 1 h and O/S = 5. Besides, the possible reaction mechanism and process are inferred based on various characterizations and experiments. Peroxy species (-SO2OOH) is the important oxidant intermediate, which oxidates DBT to corresponding sulfone. Moreover, the catalyst could be reused for 6 times without evident decrease of desulfurization efficiency .