Oxidative Desulfurisation of Model Oil and Real Sample Using MoO3/g-C3N4 Catalyst and Optimization of Operating Conditions by Box-Benken Method

In this paper, the oxidative desulfurization process has been studied using MoO3/g-C3N4 mechanically synthesized catalyst. At first, Dibenzothiophene (DBT) was selected as the target compound for synthesis of the model oil, and this model was used to optimize operating conditions. Also, H2O2 and acetonitrile were used as oxidant and extract solvents respectively. The effect of molybdenum loading on g-C3N4 and the operating conditions related to the ODS process including temperature, amount of catalyst, H2O2/DBT molar ratio, and time of reaction was investigated using the Box-Behnken (BB) method in experimental design. The maximum efficiency of DBT removal was obtained about 97.7%, at optimum conditions of 70 °C, catalyst content of 0.04 g, H2O2/DBT=8.44, and within 55 min reaction time. Also, the regeneration of the catalyst was evaluated four times, showing yield decreasing 6% for 10% MoO3/g-C3N4. Finally, at optimum conditions, performance of the catalysts in the removal of sulfur compounds of gasoline and gas oil from Oil Refining & and Distribution Company was investigated, and the obtained efficiencies of sulfur removal were 58.35% and 41% respectively. The MoO3/g-C3N4 catalyst was characterized by XRD, FTIR, EDX, FE-SEM, and BET analyses.