Preparation method of catalytic cracking catalyst for maximizing isomeric low-carbon olefin production

Abstract

The invention discloses a preparation method of a catalytic cracking catalyst for maximizing isomeric low-carbon olefin production. The method includes the steps of: (1) subjecting a Beta molecular sieve and water to beating, adding a phosphorus compound and an iron compound for modification, filtering the slurry, drying the filter cake, and then performing roasting at 550-650DEG C for 1-2h; (2) subjecting a ZSM-5 molecular sieve and water to beating, adding a certain proportion of sodium hydroxide, controlling the reaction temperature at 50-80DEG C, carrying out reaction for 0.5-2h, filteringthe slurry, and taking the filter cake for standby use; (3) subjecting the Beta molecular sieve and ZSM-5 molecular sieve treated in step (1) and (2), clay, an REUSY molecular sieve and an adhesive to beating together, and conducting acidification; and (4) carrying out spray drying on the slurry obtained in step (3) so as to obtain the needed catalyst. After modification of the Beta molecular sieve with phosphorus and iron, the cracking activity is controlled, and the isomerization performance is improved. The ZSM-5 molecular sieve is treated with sodium hydroxide, and by controlling the dealuminizing degree, the ZSM-5 molecular sieve forms the unique distribution of a silicon-rich outer surface and an aluminum-rich inner surface, and penetrating channels are constructed, so that the isomeric selectivity of the ZSM-5 molecular sieve can be greatly improved.

Description

technical field [0001] The invention relates to a catalytic cracking catalyst, in particular to a preparation method for a catalytic cracking catalyst for prolific isomeric low-carbon olefins. Background technique [0002] In recent years, with the development of the automobile industry, the compression ratio of gasoline engines has generally increased to above 9, and the demand for high-octane gasoline is increasing. In order to protect the environment, it is required to reduce the content of olefins and aromatics in gasoline. Therefore, it is necessary to produce new-formulation gasoline. At present, the method of adding ethers such as MTBE, TAME, and ETBE to gasoline is mostly used. The demand for isobutylene and isopentene as etherification raw materials is increasing day by day. [0003] Catalytic cracking gasoline accounts for more than 70% of refined oil in my country. Therefore, increasing the yield of isobutene and isopentene in the process of catalytic cracking ca...

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Problems solved by technology

[0006] CN102451753A discloses a catalyst and its preparation method, which contains 5-60% ZSM-5, BETA, USY molecular sieve, and the binder is a phosphorus-containing aluminum-based binder, which can increase the octane number by 1 point, but C 4 -C 5 Isomerized olefin yield is less than 6.0m%

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