Preparation method of high silica alumina ratio MCM-22 molecular sieve catalyst

Abstract

The invention provides a preparation method of a high silica alumina ratio MCM-22 molecular sieve catalyst. The method comprises the following steps: raw materials of sodium source, silicon source, aluminium source, boron source, templeting agent and deionized water are put in a synthesis reactor according to the mixture ratio and statically or dynamically crystallized for 1-20 days at the crystallization temperature of 110-200 DEG C, and the product is filtered, washed and dried to obtain molecular sieve initial powder; and the obtained molecular sieve initial powder is roasted in the air atmosphere at the high temperature of 450-750 DEG C so as to remove the templeting agent and is exchanged into an ammonium type molecular sieve by an ammonium ion exchange method, the ammonium type molecular sieve is roasted at the temperature of 450-750 DEG C to obtain a corresponding hydrogen type molecular sieve, and the hydrogen type molecular sieve is prepared into the high silica alumina ratio MCM-22 molecular sieve catalyst after being molded. By using the method, the MCM-22 molecular sieve catalyst with controllable silica alumina ratio, high crystallization degree and high silica alumina ratio can be prepared, and the invention breaks through the range of the silica alumina ratio of the MCM-22 molecular sieve catalyst of the conventional method and overcomes the problem of descending of crystallization degree generally existing in the post-processing method.

Description

technical field [0001] The invention relates to a preparation method of a high silicon-aluminum ratio MCM-22 molecular sieve catalyst, which can be applied to C 4 + Hydrocarbon conversion reactions such as olefin catalytic cracking have the advantages of high yield and good stability of the target product. Background technique [0002] MCM-22 molecular sieve is a molecular sieve with a layered structure, which belongs to the MWW topology, and has two sets of independent and disconnected pore systems. One is the elliptical 10-membered ring two-dimensional sinusoidal channel with a pore size of 0.40nm×0.59nm in the layer, and the other is the 12-membered ring supercage system connected by 10-membered ring openings between the layers. The size of the 12-membered ring supercage is 0.71nm×0.71nm×1.82nm. Due to its unique pore structure and physical and chemical properties, MCM-22 molecular sieve exhibits excellent catalytic performance in various hydrocarbon conversion reaction...

AI Technical Summary

Problems solved by technology

[0004] ZL200410101803.2 discloses a post-treatment method for increasing the silicon-aluminum ratio of MCM-22 molecular sieve. In this method, the MCM-22 molecular sieve is modified by ammonium fluorosilicate solution at a certain temperature, and the silicon-aluminum ratio can be as high as 180. The high-silicon MCM-22 molecular sieve, but the preparation method of the higher silicon-aluminum ratio MCM-22 molecular sieve is not mentioned in this document

Images