Performance And Mechanism Of Mo/Ti-PILC Catalyst For Oxidative Removal Of Dibenzothiophene From Oil

The existence of sulfur-containing substances in oil has brought a great threat to the environment and life.The realization of deep desulfurization of oil has always been a hot spot in the field of desulfurization.Compared with traditional hydrodesulfurization?HDS?,oxidation desulfurization?ODS?with mild reaction conditions has higher removal efficiency for stubborn sulfur-containing compounds and has broad application prospects in industry.In this study,the sulfur-containing compound dibenzothiophene?DBT?in model oil was oxidized to dibenzothiophene sulfone?DBTO₂?with large polarity by oxidation desulfurization method,and then the product was removed by filtration.In this study,molybdenum was loaded on titanium modified montmorilloni te by adsorption as catalyst?Mo/Ti-PILC?.The structure of Mo/Ti-PILC was characterized by SEM,TEM,N₂-physisorption,FTIR,XRD and XPS.The results showed that montmorillonite?MMT?was an interlayer mesoporous structure.After being modified by titanium crosslinker,the large and thick laminates were stripped into fine fragments.Titanium crosslinker was retained in the interlayer with TiO₂ particles,which played the role of supporting the montmorillonite layer.Molybdenum was successfully loaded on titanium-crosslinked montmorillonite,and the titanium and molybdenum on montmorillonite were independent,and there was no chemical bond between them.The single factor variable experiments were carried out with the method of controlling variables,including the reaction time,the reaction temperature,the amount of catalyst and the molar ratio of cyclohexanone peroxide to dibenzothiophene?O/S?.The results showed that the effects of reaction time,temperature and O/S on the conversion of DBT were slightly greater.When the catalyst dosage was 0.100 g,the O/S was 2.0,and the temperature was 100^oC,the DBT could be completely oxidized in half an hour.According to the results of single factor experiment,the optimal design of response surface was carried ou t by Box-Behnken.The interaction effects of reaction time,temperature and O/S on the conversion of DBT and the optimal reaction conditions were investigated.The results showed that the maximum oxidation rate of DBT was 100%when the reaction time was 40 minutes,the reaction temperature was 93^oC and the O/S was 3.10.The effects of three independent factors on the conversion of DBT were as follows:O/S>reaction temperature>reaction time.In addition,the oxidation product was removed by filtration,which was compared with the traditional extraction method for removing oxidation products.The results showed that there was no significant difference between the two methods,the sulfur concentration in the oil was reduced to less than10 mg/L in this study.However,compared with the extraction operation,filtration was simpler and more economical.The catalytic properties of Mo/Ti-PILC were tested by comparison experiments of different desulfurization systems.The results showed that the existence of Mo/Ti-PILC could greatly improve the conversion of DBT,and compared with Mo/Na-MMT,Ti-PILC and Na-MMT,Mo/Ti-PILC exhibited better catalytic performance.At the same time,the cyclic experiment and leaching experiment of Mo/Ti-PILC showed that the catalyst had excellent stability.All of these indicated that the catalyst had potential industrial application value.