چكيده به لاتين
Due to stringent environmental regulations, deep desulfurization of fossil fuels and the achievement of global standards have become increasingly important. The main method of desulfurization of fossil fuels in the industry is Hydrogen Desulfurization (HDS). But due to operational conditions such as high temperature (300-400˚C) and the pressure (200-100 atmospheres), this method is not cost effective for deep desulfurization. Among alternative or complementary methods, oxidative desulfurization (ODS) is a promising process for deep desulfurization, which has more suitable operating conditions (less than 100˚C and atmospheric pressure) and more economical. But analyzing the catalysis and other effective parameters are needed. In this study, MoOx-VOx/Al2O3 as a bimetallic catalyst was prepared by successive-impregnation and co-impregnation methods. Subsequently, the performance of these catalysts was evaluated in the oxidative desulfurization process. Two different types of oxidizing agents, TBHP and H2O2, were used for the catalytic ODS process. To investigate the effect of extraction solvent, acetonitrile was used. Among the two methods of making the catalyst, the co-impregnation (99.33% removal in 20 minutes) showed the best result. Co-imp (MoOx-VOx/Al2O3) with TBHP oxidant, without solvent extraction at 60 ° C in 30 minutes completes removal of sulfur. In order to better evaluate the performance of Co-imp (MoOx-VOx/ Al2O3) in industrial fuel (for sulfur removal), the effect of the presence of competitive compounds in optimal reaction conditions was investigated. Indole had the most negative effect on ODS between nitrogenous compounds which increased the total removal of sulfur to 60 minutes. Among the hydrocarbon compounds, cyclohexene as the representative of the olefins group, had the most negative effect on ODS, in the presence of cyclohexene sulfur removal was not completed in 90 minutes and reached 80%. P-xylene, as an aromatic agent, had a positive effect on ODS (complete removal in 20 minutes) due to solubilization of its oxidized compounds. The simultaneous presence of acetonitrile and oxidizing agent TBHP reduced the removal rate to 48%. In the presence of hydrocarbon and sulfur compounds, with an increase in the ratio of O/S from 2/5 to 10, the removal rate increased from 30% to 90%, indicating the competition of hydrocarbon compounds in oxidant.
