Catalytic cracking catalyst

Abstract

The invention provides a catalytic cracking catalyst. The catalytic cracking catalyst contains a modified Y type molecular sieve containing phosphorus and rare earth, alumina containing an additive and clay. The modified Y type molecular sieve containing phosphorus and rare earth comprises 4 to 11 wt% of rare earth, 0.05 to 10 wt% of phosphorus and 0.1 to 0.7 wt% of sodium oxide, and has a pore volume is 0.33 to 0.39 mL / g; the volume of pores with pore diameters of 2 to 100 nm accounts for 15 to 30% of a total pore volume; a lattice constant is 2.440 nm to 2.455 nm; the content of non-framework aluminum is no more than 20% of total aluminum content; lattice collapse temperature is more than 1050 DEG C; and a ratio of the amount of acid B to the amount of acid L is no less than 2.50. The catalyst has higher heavy oil cracking activity, good coke selectivity, and high gasoline yield, liquefied gas yield and total liquid yield.

Description

technical field [0001] The invention relates to a catalytic cracking catalyst and a preparation method thereof. Background technique [0002] With the increasing weight of catalytic cracking raw oil and the increasingly stringent environmental protection regulations, catalytic cracking catalysts are required to improve the conversion capacity of heavy oil and at the same time produce more gasoline. The key to obtaining high-yield gasoline is that the active component of the catalyst, that is, the rare earth high-silicon Y-type zeolite, can keep the crystal structure intact, have high thermal and hydrothermal stability, and have strong acidity and low acid density. [0003] 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. The disadvantages of zeolite...

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. The disadvantages of zeolite are: because too harsh hydrothermal treatment conditions will destroy the structure of zeolite, Y-type zeolite with high silicon-alumina ratio cannot be obtained; although the production of aluminum outside the framework is very important for improving the stability of zeolite and forming new acid centers Beneficial, but 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, often resulting in lattice defects of zeolite, and the crystallization of zeolite remains Therefore, the thermal and hydrothermal stability of the rare earth-containing high-silicon Y-type zeolite prepared by the hydrothermal method is relatively poor, which is manifested in the low lattice collapse temperature, the crystallinity retention rate and the ratio of crystallinity after hydrothermal aging. low surface area retention

The cracking activity of the catalyst made of the zeolite as the active component is not high, and the conversion rate of heavy oil is low

[0013] Existing cracking catalysts of ultra-stable Y-type molecular sieves containing phosphorus and rare earths have low cracking activity for heavy oil and poor coke selectivity

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