A kind of catalytic cracking catalyst and its preparation and application

Abstract

The invention discloses a catalytic cracking catalyst as well as preparation and application thereof. The catalyst contains a modified Y-type molecular sieve, an aluminum oxide binder and clay; according to the modified Y-type molecular sieve, the content of magnesium oxide in the modified Y-type molecular sieve is 0.5-4.5 wt%; the content of sodium oxide is 0.1 wt%-0.5 wt%; the total pore volumeis 0.33 mL / g to 0.39 mL / g; the pore volume of secondary pores with the pore diameter of 2nm-100nm of the modified Y-type molecular sieve accounts for 10%-25% of the total pore volume, the lattice constant is 2.440 to 2.455nm, the content of non-skeleton aluminum in the modified Y-type molecular sieve is not higher than 20% of the total aluminum content, the lattice collapse temperature is not lower than 1040 DEG C, and the ratio of the amount of acid B to the amount of acid L in the total acid amount of the modified Y-type molecular sieve, which is measured by pyridine adsorption infrared method at 200 DEG C, is not lower than 2.30; when the molecular sieve is used for ultraviolet and visible light analysis, the ultraviolet and visible absorption spectrum is not absorbed at the wavelengthof 285-295 nm. The catalytic cracking catalyst is used for catalytic cracking of heavy oil, and has the advantages of low coke selectivity, high gasoline yield, high liquefied gas yield and high isohydrocarbon content in gasoline.

Description

technical field [0001] The invention relates to a catalyst for catalytic cracking of heavy oil, its preparation method and application. Background technique [0002] At present, the industrial production of high-silicon Y-type zeolite mainly adopts the hydrothermal method. Rare earth-containing high-silicon Y-type zeolite can be prepared by performing multiple rare-earth ion exchanges and multiple high-temperature roasting on NaY zeolite. Zeolite has the following disadvantages: the structure of zeolite can be destroyed due to too harsh hydrothermal treatment conditions, and Y-type zeolite with a high silicon-aluminum ratio cannot be obtained; although the production of aluminum outside the framework is beneficial to improving the stability of zeolite and forming new acid centers, However, too much aluminum outside the framework reduces the selectivity of zeolite; in addition, many dealuminated holes in zeolite cannot be filled by silicon migrated from the framework in time...

AI Technical Summary

Problems solved by technology

Rare earth-containing high-silicon Y-type zeolite can be prepared by performing multiple rare-earth ion exchanges and multiple high-temperature roasting on NaY zeolite. Zeolite has the following disadvantages: the structure of zeolite can be destroyed due to too harsh hydrothermal treatment conditions, and Y-type zeolite with a high silicon-aluminum ratio cannot be obtained; although the production of aluminum outside the framework is beneficial to improving the stability of zeolite and forming new acid centers, However, too much aluminum outside the framework reduces the selectivity of zeolite; in addition, many dealuminated holes in zeolite cannot be filled by silicon migrated from the framework in time, which often causes lattice defects of zeolite, and the crystallization retention of zeolite is relatively low. Low

However, the Y molecular sieve prepared by this method has poor thermal and hydrothermal stability, unsatisfactory reactivity and selectivity, and can only increase the content of isobutane under certain conditions, but cannot effectively increase the content of isomeric hydrocarbons in gasoline

[0007] The performance of the ultra-stable molecular sieves prepared by the hydrothermal method or the gas phase method in the prior art cannot well meet the current needs of processing heavy oil and inferior oil and improving the quality of gasoline

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