Preparation And Hydrodesulfurization Performance Of Aluminum Based NiMo Catalyst

The organic sulfides in gasoline can form sulfur oxides after combustion and float in the air.This has a serious negative impact on human health.Therefore,my country has implemented the?standard for fuel oil,which stipulates that the sulfur content drops to 10 mg/kg in gasoline.This makes gasoline processing requirements increasingly stringent.The hydrodesulfurization technology has always been regarded as the most effective and economical petroleum fraction refining technology in gasoline production methods.This method mainly converts organic sulfides into hydrogen sulfide to remove sulfur in gasoline.In the existing technology,the hydrodesulfurization capacity of the catalyst is the bottleneck of this method,and designing and developing a high-performance catalyst is the most important task.The first step to carry out this research is preparing three different crystalline alumina carriers.The main research was to support the Ni Mo active component on its surface.In the performance test of desulfurization and hydrogenation,Ni Mo/?-Al2O3catalyst has the best desulfurization efficiency,reaching 91.1%.By a series of characterization methods,it is proved that?-Al₂O₃is the carrier mainly because it is called a suitable pore distribution which improves the dispersion of the active components of Ni Mo and promotes the reduction and sulfidation of Mo⁶⁺and Mo⁴⁺.So The catalyst has the best activity.We also continued to explore the effect of sulfuration parameters on catalyst performance.When sulfided in the catalyst body,the vulcanization temperature is 320?,the pressure is 35bar,and the time is 2 h.After activation,the catalyst has the best hydrodesulfurization performance.The second step,we use the method of solution gelatum to get the TiO₂-Al₂O₃composite oxide support.The addition of TiO₂reduces the pore size of the catalyst,and at the same time weakens the interaction between Mo⁶⁺and alumina,and promotes the transformation of Mo⁶⁺into active phase Mo S₂ during sulfidation.In the performance test of desulfurization and hydrogenation,the Ni Mo/TiO₂-A1₂O₃(10)catalyst has the best activity.At the same time,we continued to discuss the effections of the reaction factors for the activity of the catalyst.When the temperature is 320?,the volumetric space velocity is 10 h^-1,the ratio of hydrogen to oil is 700 and the pressure is 4.0 MPa,the catalyst can exhibit good desulfurization performance,and the sulfur removal capacity can reach 96.9%.The third step of my research is using TiO2-A1₂O₃(10)composite oxide explore the effect of complexing agent on NiMo/TiO₂-A1₂O₃(10)catalyst on the performance of catalyst hydrodesulfurization.The addition of the complexing agent can effectively improve the distribution of the active component,the dispersion degree of the active component is significantly improved,More active phase Co-Mo-based sulfides can be produced by deepening the sulfiding reaction of active components.The synergism between the active component and the carrier was enhanced by adding the complexing agent.C₆H₈O₇ had the best effect on improving NiMo/TiO₂-A1₂O₃(10)catalyst and had the best desulfurization activity.When the molar ratio of nickel to C₆H₈O₇ is 2:3,the catalyst activity is the highest?When the molar ratio of citric acid and nickel is 1.5,the catalyst activity is the highest,and the removal rate of 4,6-DMDBT in the simulated oil reaches 97.5%.