Alkaline silica sol composition and application thereof in preparation of cracking catalyst

Abstract

The invention relates to an alkaline silica sol composition and an application thereof in the preparation of a cracking catalyst, and the alkaline silica sol composition contains 0.9-7% by weight of alkali metal oxide, 3-20% by weight of SiO2, 0.5-7% by weight of acid radical and the balance of water, the pH value of the alkaline silica sol composition is 10-11.5; and the silica sol composition is used for preparing the cracking catalyst, and the preparation comprises the steps of mixing the silica sol composition with a NaY molecular sieve, beating, then spray drying, carrying out ion exchange and drying. The cracking catalyst prepared by the preparation method of the cracking catalyst has the advantages of high pore volume, strong heavy oil conversion capacity and high yield of gasoline.

Description

technical field [0001] The invention relates to an alkaline silica sol composition and its application in the preparation of catalytic cracking catalysts. Background technique [0002] Silica sol is widely used in the fields of casting, textile, papermaking, metallurgy and catalyst preparation, including acidic silica sol and alkaline silica sol. The commonly used methods for preparing silica sol include ion exchange, elemental silicon dissolution, electrodialysis and neutralization peace law. [0003] At present, the ion exchange method is mainly used to prepare alkaline silica sol. In this method, acidic silica sol is prepared by reacting water glass with strong acid ion exchange resin, and then adjusting the pH value with ammonia water, etc., and then evaporating and concentrating to obtain the required silica sol. This method has high energy consumption, and the regeneration of the ion exchange resin produces a large amount of waste water, resulting in high cost. [00...

AI Technical Summary

Problems solved by technology

However, the pore volume of the catalyst prepared by acidic silica sol is low, which is not conducive to the cracking of macromolecules, and the stability of acidic silica sol is relatively poor. It needs to be stable at a lower pH value and temperature (usually below 30 ° C), and requires all The pH value of the prepared catalyst slurry should be low enough, otherwise the formed slurry is easy to gel, which requires that when using molecular sieves, alumina substrates and other component slurries to prepare catalysts, the various slurries should have a lower pH value, and usually It is necessary to adjust the pH value of the molecular sieve slurry to be acidic; however, active components such as zeolite commonly used in cracking catalysts are easily destroyed when the pH value is too low, and the activity is reduced. Therefore, acidic silica sol is not suitable for the method of directly using NaY molecular sieves to prepare catalysts.