Preparation Of Cerium-vanadium Bimetallic Catalyst And Its Application In Oxidation Desulfurization Of Diesel Oil

Fuel is one of the main energy sources used in today’s society.The sulfur-containing compounds in the fuel will cause environmental problems such as smog after burning,and also endanger human health.In order to avoid the harm caused by sulfur-containing compounds,countries around the world have formulated strict Laws and regulations restrict the sulfur content in fuel oil,and my country stipulates that the sulfur content in fuel oil is less than 10 ppm.The current desulfurization method used in the industry is hydrodesulfurization.This technology requires harsh operating conditions such as high temperature and high pressure,and has a mediocre removal effect on thiophene sulfides.Therefore,it is urgent to develop new technical means to solve the problem of ultra-deep fuel desulfurization.Supported metal salt catalysts have the advantages of adjustable structure,excellent catalytic activity,and good reusability.In this paper,cerium and vanadium bimetal salt supported on different supports are used as heterogeneous catalysts to activate oxygen in the air.Catalytic oxidation desulfurization reaction has achieved good results.First,the CeVO₄/SiO₂ catalyst with silica as the carrier was prepared by the hydrothermal-calcination method,and the successful preparation of the catalyst was verified by a series of characterizations.The study investigated the influence of the catalyst active component loading,calcination temperature,calcination time and other factors on the catalytic activity of the catalyst,and determined the optimal preparation with an active component loading of 5%,a calcination temperature of 700 degrees Celsius,and a calcination time of 3 hours.Under the optimal preparation conditions,the desulfurization experimental conditions have been investigated for the influencing factors of the desulfurization rate.The optimal desulfurization experimental conditions are reaction temperature 130 degrees Celsius,catalyst addition amount 0.06 g/20 g simulated oil,air inlet rate 150 mL/min,The stirring rate is 600 rpm.Under this reaction condition,the removal rate of DBT,4,6-DMDBT and BT can reach 98.59%,99.24%and 70.09%respectively after 3 hours of reaction.After adding cycloalkanes,olefins,aromatics and other substances to the simulated oil at the same time,the desulfurization rate decreased to 79.76%,which is due to the reaction of olefins in the system.The desulfurization rate of the catalyst is 90.08%after being recycled for 6 times,and it has good reusability.Through free radical quenching experiment and infrared characterization of oxidation products,the mechanism of oxidation process was explored.In order to enhance the interaction between the support and the active components,nano-flaky boron nitride was selected as the support to prepare the catalyst,and the active components remained unchanged.The catalyst was characterized by XRD,XPS and other means,and the optimal preparation conditions of the catalyst were determined.The active component loading is 10%,the calcination temperature is 500 degrees Celsius,and the calcination time is 3 hours.The catalyst prepared under these conditions has good catalytic performance.Under the optimal desulfurization conditions,4,6-DMDBT can be After complete removal,the removal rates of DBT and BT are 99.62%and 71.29%,respectively,and the catalyst has good reusability.The desulfurization rate for the first three times of recycling is basically unchanged,and the desulfurization rate is 91.12%for the sixth time.In this study,two heterogeneous catalysts were prepared for oxidative desulfurization of fuel oil,which provides a new possibility for ultra-deep fuel desulfurization in the future.