Oxidative desulfurization of model fuel using a NiO-MoO3 catalyst supported by activated carbon: Optimization study

In this study, oxidative desulfurization of dibenzothiophene (DBT) with an H2O2-acetic acid system whereas the catalyst used is molybdenum oxide supported on activated carbon (AC). The effect of loading nickel oxide as a promoter as well as the impact of catalyst dosage and the initial sulfur concentration were investigated. The ranges for these parameters are catalyst dosage (0.5-1.5) g, nickel loading (2-6) wt.% and initial sulfur concentration (400-800) ppm. A Response Surface Methodology (RSM) combined with Box-Behnken design (BBD) was utilized to evaluate the impacts of studied variables; the evaluation consists of the level of order significance of each factor, the interaction effects of parameters was analyzed with Analysis of variance (ANOVA) and determine the optimum conditions for oxidative desulfurization (ODS). Results showed that sulfur removal efficiency from model fuel ranged between 23 and 71%, and these results were fitted with a second-order polynomial model with a high correlation coefficient R2 (0.9719). The optimal condition for DBT oxidation is 0.5 g. Ni wt. 6% and 700 ppm for catalyst dosage, nickel loading, and initial sulfur concentration respectively.