| In recent years, as the demand of low carbon olefins especially propylene increased,the production of low carbon olefins has become the new trendency in oil refining industry. DCC(Deep Catalytic Cracking) technology in place of the thermal cracking technology producing ethylene and propylene, which could largely decrease energy consumption and optimize product composition, obtaining great profits. Presently, the delayed coking productive capacity of China oil refinery increases continuously, and the yield of the coker gasoline also increases quickly, but coker gasoline has not extensive application.Producing propylene by coker gasoline deep catalytic cracking not only improves the quality of coker gasoline, but also produces low carbon olefins. With coker gasoline as raw material, the reaction rules of catalytic pyrolysis on coker gasoline were studied in a small confined fluid bed reactor and riser reactor. The results showed that in a small confined fluid bed reactor, the different hydrocarbon composition had major effect on propylene production, and the yields of propylene were mainly influenced by temperature, catalyst-to-oil ratio and space velocity. The high reaction temperature, appropriate ratio of catalyst to oil and low space velocity could promote gasoline catalytic cracking, and increase yield of propylene. The effect of different catalysts on coker gasoline deep catalytic cracking showed that the LTB-2 catalyst was best for production of propylene. Under the same reaction conditions, compared to the other two catalysts, LCC-200 and MMC-2, using LTB-2 catalyst, the yield of propylene increased by 3.5% and 1.1% respectively. The results showed that in riser reactor at the temperature of 560℃, the yield of LPG was 34.08%, the yield of propylene was 14.69%, and the olefin content in gasoline reduced from 32.17% to 14.99%, the aromatic content increased from 13.82% to 37.52%, the content of sulfur and nitrogen decreased clearly, the quality of gasoline was improved.
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