Preparation And Oxidative Desulfurization Performance Evaluation Of Supported Tungsten Catalysts

Tungsten-based catalysts had been proved that it have hight catalytic activity in oxidative desulfurization. Therefore, this kinds of catalysts become important in oxidative desulfurization and used everywhere. We prepared some catalysts base on works of previous researches and our group. Two kinds of WO3/SBA-15 catalyst were synthesized by the wetness impregnation method from two alternative tungsten precursors with SBA-15 mesoporous sieve as carrier. Two samples were characterized by XRD, and FT-IR, and two catalyst was applied in the oxidative desulfurization of simulated oil (sulfur concentration of 500μg/g), after reaction oil phase was extracted by 1-methyl-2-Pyrrolidinone, Effect of the extractant dosage, extraction time, catalyst amount, reaction temperature, reaction time on desulfurization rate were investigated. Characterization results show that WO3/SBA-15 molecular sieve still had highly ordered two-diemensional hexagonal mesoporous structure, and WO3 species is highly dispersed in the SBA-15. The experimental results show that oxidation-extraction desulfurization effect is very good with the catalyst prepared through tungstic acid with oxalic acid as tungsten source under optimizing condition: reaction temperature was 320K, the reaction time was 3h, extractant to oil ratio of 0.5, extraction time 5min, the amount of catalyst conditions 0.12g,60ml oil, and 0.57mL 30% H2O2, desulfurization rate can reach 94.05% under optimizing condition.ODS activities of Catalysts were evaluated in gasoline(sulfur concentration of 4632.03μg/g) and diesel(sulfur concentration of 8898.69μg/g). One method is:before ODS of gasoline and diesel, gasoline and diesel had been adsorbed by NaY for 180min, The WO3/SBA-15 catalyst had the high desulfurization performance under optimizing condition:reaction temperature was 323K, the reaction time was 90min, extractant to oil ratio of 1, the amount of catalyst conditions 0.1g,10ml oil, and 0.3mL 30% H2O2, sulfur concentration of gasoline was removed from 4632.03μg/g to 465.05μg/g and sulfur concentration of diesel was removed from 8898.69μg/g to 1881.90μg/g. Another method is:Direct ODS of gasoline and diesel without adsorption under the following reaction conditions:reaction temperature was 333K, the reaction time was 90min, extractant to oil ratio of 1, the amount of catalyst conditions 0.2g,10ml gasoline,1.3mL 30% H2O2 lOmL, and two extraction cycles, After reaction sulfur concentrateion of gasoline was removed from 4632.03μg/g to 385.91μg/g.