Research On The Preparation And Catalytic Performance Of Supported DUSY Catalyst For N-heptane Hydroisomerization

In recent years, the demand of the national production and life of gasoline, diesel oil and its by-products increased year by year, as their raw materials, petroleum exploitation and utilization of human production and life become more and more important, which also indirectly promote the chain of downstream products, research and development of molecular sieve catalysts. Molecular sieve catalyst from the traditional to the new type of change is the trend. The molecular sieve of different kinds of physicochemical properties and catalytic performance of the difference is large, it is also one of the reasons caused by the molecular sieve catalyst of widespread concern. Ultrastable Y zeolite molecular sieve（USY） for its good physical and chemical properties, it can be as the acidity of the catalyst, component or carrier,used in with catalytic hydrocracking, hydrotreating, in the production process. The dealumination physicochemical properties of DUSY molecular sieve prepared with USY molecular sieve is more excellent, gradually by scholars and manufacturers favor.In this paper, USY molecular sieve as carrier was dealuminated by modifying in hole（pore） more rich and appropriate isomerization acid modified molecular sieve, and in the carrier metal supported molybdenum carbide. The effects of catalyst preparation in n-heptane hydroisomerization reaction in catalytic performance. On the first of the USY molecular sieve aluminum removal, selection of citric acid and oxalic acid dealumination agent were investigated two modified conditions: acid concentration, temperature, solvents in, and through on dealuminated USY molecular sieve structure characterization and catalytic performance evaluation, selected two dealumination agent the best modified conditions. And the effects of the heteropoly acid on the acidity of the modified zeolites. The results show that the load 10%（mass fraction） heteropoly acid of preparation of catalyst crystal structure was severely damaged. Different acid modified molecular sieve found modified with citric acid results in oxalic acid modified results, citric acid instead of 0.20DUSY-90 catalyst for positive heptane isomerization selectivity reached 78.6%, conversion rate was 64.4%. Finally choose to citric acid change of molecular sieve as a carrier, the load metal molybdenum carbide of catalyst, to modified molecular sieve increased metal active sites, and the effects of the amount of the impregnation of Mo, Mo calcination temperature, carbonization conditions of catalyst, the reaction condition of n-heptane isomerization reaction of reminders of and citric acid modified catalysts prepared in Mo₂C/0.20DUSY-90 the conversion rate was 74%,the selectivity to 80.1%.