Heavy oil catalytic cracking catalyst and preparation method thereof

Abstract

The invention discloses a heavy oil catalytic cracking catalyst and a preparation method thereof, aiming at solving the problems of a catalytic cracking catalyst in the prior art that the preparationcost is relatively high, the pore volume of an active matrix material is low, the pore diameter is small and only an LC center exists and the like. The catalyst is a mesoporous and macroporous silicon-aluminum material with a center containing rich B acid. Based on the weight of oxide, an anhydrous chemical expression formula of the silicon-aluminum material is as follows: (0-0.3) Na2O: (2-18) Al2O3: (82-98) SiO2; the pore volume is 0.8 to 2mlg<-1>, the specific surface area is 150 to 350m<2>g<-1>, the most probable pore diameter is 30 to 100nm and the B / L acid specific value is 0.8 to 2.0. The catalyst disclosed by the invention has better matrix acidity distribution and higher pore volume and the characteristics of strong heavy oil conversion capability in catalytic cracking reaction andhigh total liquid yield.

Description

technical field [0001] The invention belongs to the field of oil refining catalysts, and in particular relates to a heavy oil catalytic cracking catalyst and a preparation method thereof. Background technique [0002] The catalytic cracking reaction is a parallel relay reaction. The active center of the catalytic cracking catalyst is a Y-type molecular sieve. The orifice of the Y-type molecular sieve is a twelve-membered ring with a pore diameter of about 0.7nm. The diameter of heavy oil macromolecules is 1-6nm, which cannot enter the Y-type molecular sieve. Inside the molecular sieve, therefore, the cracking of heavy oil macromolecules mainly takes place on the matrix. Heavy oil macromolecules are cracked into secondary molecules on the matrix, and the secondary molecules further enter molecular sieves to be cracked into small molecules. Due to diffusion limitations, the ideal pore size for heavy oil cracking is 6 to 10 times the molecular diameter, and the corresponding p...

AI Technical Summary

Problems solved by technology

At present, the active matrix material of domestic catalytic cracking catalysts is mainly made of alumina, but this material has problems such as low pore volume, small pore size, and only L acid centers, which cannot meet the cracking needs of heavy and low-quality oil products.

In order to improve the pore structure and acid distribution of catalytic cracking catalyst substrates, researchers have carried out a large number of synthesis and preparation studies of medium and large porous silica-alumina materials. The pore structure and acidity distribution have been improved to some extent, but the existing synthesized silica-alumina materials still exist. High cost, low B / L acid ratio, etc., and the pore structure needs to be further improved

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