Method for improving pore structure of kaolin microsphere in-situ crystallization product

Abstract

The invention relates to a method for improving the pore structure of a kaolin microsphere in-situ crystallization product. The method comprises the following steps of: preparing kaolin spray microspheres with the particle sizes of between 20 and 110 mu m by using mixed kaolin grout by spray drying, wherein the mixed grout comprises kaolin, deionized water, a dispersant and an organic pore cannelforming template agent; the dispersant is sodium silicate or sodium pyrophosphate; and the organic pore cannel forming template agent is polyvinyl pyrrolidone or polyvinyl alcohol; baking the spray microspheres at the temperature of between 900 and 1,100 DEG C for 1 to 3 hours so as to obtain kaolin baked microspheres; mixing the kaolin baked microspheres with the mullite content of between 2 and12 percent, sodium silicate, a directing agent, solution of sodium hydroxide and deionized water; crystalizing the mixture at the temperature of between 90 and 95 DEG C for 16 to 36 hours; and filtering and drying so as to obtain a crystallization product which has a medium / large-pore structure and comprises a NaY molecular sieve. The crystallization product has a well-developed large-pore structure and the abrasion index of not more than 1.5 percent and comprises 20 to 50 percent of NaY molecular sieve.

Description

technical field [0001] The invention belongs to the field of preparation of oil refining catalysts, and more specifically relates to a method for synthesizing in-situ crystallization products with well-developed pore structures by using kaolin clay spray microspheres as raw materials. The crystallization product synthesized by this method can be used as the precursor for preparing catalytic cracking catalyst. Background technique [0002] The purpose of the fluidized catalytic cracking (FCC) reaction is the process of producing gasoline, diesel, liquefied petroleum gas and other small molecular products through catalytic reactions of heavy raw materials with large molecules. As crude oil becomes heavier and worse, increasing the processing ratio of macromolecular heavy oil, especially residual oil, in the FCC process is of great significance for improving the economic benefits of refineries. Taking the heavy oil catalytic cracking unit with a processing capacity of 3 millio...

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Problems solved by technology

However, in terms of pore structure design, on the one hand, it focuses on strengthening the formation of natural channels of kaolin, on the other hand, it increases the pore volume by increasing the void ratio, but the adjustability and regularity of the channels are insufficient.

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