Oxidative desulfurization of model oil and oil cuts with MoO3/SBA-15: experimental design and optimization by Box–Behnken method

Abstract

Using wet impregnation method, MoO3 particles were loaded on hierarchical silica support, SBA-15, and applied for oxidative desulfurization (ODS) process from a model oil containing dibenzothiophene (DBT). The experiments were carried out by the use of H2O2 and acetonitrile as oxidant and extractant. The MoO3/SBA-15 catalyst was characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FE-SEM) and Brunauer–Emmett–Teller (BET) analyses. At first, the effect of molybdenum loading was examined. Then, the effect of operating parameters on ODS including temperature, catalyst dosage, the molar ratio of H2O2/DBT and reaction time were investigated using Box–Behnken experimental design. The complete efficiency, ~ 100% S removal, was achieved by 0.004 g mL−1 catalyst at 55 oC within 49 min reaction time and H2O2/DBT = 9. At the optimized operating conditions, real oil cuts of gasoline and gas oil were tested and the S removal efficiency of 69.73% and 49% was achieved. The desulfurization activity of the catalyst from DBT model oil after 5 times regeneration was above 93%.