Oxidative desulfurization of diesel oil over Ti-MWW catalyst with TBHP as oxidant

Oxidative desulfurization (ODS) of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (DMDBT) in model light oil was investigated with different oxidants over Ti-MWW catalyst. The results indicated that tert-butyl hydroperoxide (TBHP) exhibits higher reactivity with these organic sulfur-containing compounds than hydogen peroxide. In the presence of TBHP, the reactivity of these sulfur-containing compounds over Ti-MWW catalyst is in the order of DBT > DMDBT > BT, which is determined by the electron density of sulfur atom in thiophene ring as well as the steric hindrance of sulfur compounds. ODS of a commercial diesel oil was also investigated over the Ti-MWW/TBHP system. The sulfur compounds in the commercial diesel oil can be efficiently oxidized to corresponding sulfone under mild reaction conditions; by oxidation and extraction twice, the sulfur content in the commercial diesel oil is decreased from 1 015 μg/mL to 11 μg/mL and the sulfur removal reaches 99%.