Cracking catalyst and its application

Abstract

A cracking catalyst is prepared from molecular sieve (10-60 Wt%), clay (0-75), Si adhesive (5-40), Al adhesive (5-40) and modifier (0-10) through preparing slurry in sol state, spray drying to become gel, ageing and forming big pores. Its advantages are high strength, stack density and pore volume, high conversion rate of hydrocarbon oil, and high cracking power and selectivity.

Description

Technical field [0001] The invention relates to a hydrocarbon catalytic cracking catalyst, more specifically to a semi-synthetic hydrocarbon cracking catalyst with silica alumina sol as a binder. Background technique [0002] In recent years, due to the heavy and degraded raw materials, the content of molecular sieve in the catalyst has been increasing, which has caused the cost of the catalyst to continue to rise. Moreover, the catalyst carrier with pseudo-boehmite and aluminum sol as the binder can no longer withstand molecular sieve. Further increase in volume. Therefore, the cracking ability of the catalyst carrier must be exerted to reduce the amount of molecular sieve. This requires the carrier to have a certain acidity and appropriate macroporous structure while ensuring good adhesion. [0003] U.S. Patent No. 3,867,308 discloses a catalyst prepared by a semi-synthetic process using sodium-containing silica sol as a binder. Although the carrier has strong binding force, it...

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Problems solved by technology

However, the catalyst prepared by this method also has unfavorable factors such as large bulk density, low surface area, and small pore volume.

Moreover, two kinds of silica sols are used in its preparation method, one is ion-exchanged low-sodium silica sol, and the other is silica sol containing aluminum sulfate buffer solution, so the preparation process is relatively complicated.

[0013] It can be seen from the previous work that the silica-alumina gel catalyst prepared by the total synthesis process has the advantages of high activity and good stability, but the catalyst has a small bulk density, poor carrier cohesion, and low molecular sieve tolerance. And the preparation process is relatively complicated; while the catalytic cracking catalyst using silica sol as the binder has good wear resistance, and the preparation process is simple, but the bulk density is large, the surface area is low, the pore volume is small, and the matrix activity is low; Aluminum sol can improve the pore structure of the catalyst to a certain extent, but sodium-free or low-sodium silica sol is often used to prepare catalysts, and the preparation of sodium-free or low-sodium silica sol requires ion exchange, so the preparation process is complicated and costly. high, difficult to use in industry