Catalytic cracking catalyst and preparation method thereof

Abstract

The invention relates to the field of catalytic cracking catalyst preparation, and discloses a catalytic cracking catalyst and a preparation method thereof. The method comprises the following steps: sequentially carrying out ion exchange reaction, hydro-thermal ultra-stabilization treatment, first roasting, gas-phase chemical isomorphous substitution reaction, and gas-solid separation on a NaY molecular sieve, so as to obtain a modified molecular sieve, then carrying out gelling on the obtained modified molecular sieve with clay and an adhesive, and sequentially carrying out drying and secondary roasting on the obtained gelling product, wherein the temperature of the molecular sieve subjected to the first roasting is 350-600 DEG C through the hydro-thermal ultra-stabilization treatment andthe first roasting method, and the solid content is not lower than 98 wt%. The preparation method provided by the invention is simple in process flow, the production energy consumption of the catalytic cracking catalyst is greatly reduced, and the prepared catalytic cracking catalyst has relatively high conversion rate, light-oil yield and liquid yield, and has relatively low coke selectivity.

Description

technical field [0001] The invention relates to the field of catalytic cracking catalyst preparation, in particular to a catalytic cracking catalyst and a preparation method thereof. Background technique [0002] Molecular sieve is a widely used material in catalytic cracking catalyst, and it is also a very important component. The performance of molecular sieve directly affects the reaction performance of catalytic cracking catalyst. According to different needs, molecular sieves can be modified differently to meet the requirements of use. For example, molecular sieves with a high silicon-to-aluminum ratio are generally considered to be required for catalytic cracking catalysts. [0003] In the preparation of molecular sieves with high silicon-aluminum ratio, there are mainly the following methods: ammonium fluorosilicate method to extract aluminum and supplement silicon, hydrothermal method and gas phase chemical method to extract aluminum and supplement silicon (the pres...

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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

[0014] It can be seen that the high-silicon Y-type molecular sieve prepared by the simple hydrothermal method requires multiple times of high-temperature steam roasting and multiple rare earth ion exchange modifications. The prepared molecular sieve has secondary pores, but the rare earth content is low and the degree of crystallinity retention is low. The thermal and hydrothermal stability is low. In addition, because the high-temperature water vapor in the preparation process of the hydrothermal method has a great damage effect on the crystallinity of the molecular sieve, the hydrothermal method cannot prepare high-silicon crystals with high crystallinity and high silicon-aluminum ratio. Molecular sieves; gas-phase method can prepare high-silicon molecular sieves with high crystallinity and high silicon-aluminum ratio, which have good thermal and hydrothermal stability. However, the micropore structure of ultra-stable molecular sieves prepared by gas-phase method remains intact without secondary pore structure

Therefore, the properties of the ultrastable molecular sieves prepared by the hydrothermal method or the gas phase method in the prior art cannot well meet the needs of the current processing of heavy oil and inferior oil. The ultrastable molecular sieves prepared by the hydrothermal method or the gas phase method are produced The catalyst used in the catalytic cracking process has the defects of low conversion rate, light oil yield and liquid yield, and high coke selectivity

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