ZSM-5 type molecular sieve for catalyst for reaction for preparing propylene from methanol and/or dimethyl ether

Abstract

The present invention provides a ZSM-5 type molecular sieve catalyst for a reaction for preparing propylene from methanol and / or dimethyl ether, which has a silica alumina ratio of 250-1,150 and a grain diameter of 65-250nm. A preparation method of the molecular sieve comprises the following steps: (1) mixing an aluminum source and an organic directing agent and stirring an obtained mixture at constant temperature of 0-30 DEG C for 2-24 hours; (2) adding a silicon source and an organic addition agent to the mixed solution obtained in the step (1) and continuing stirring the mixed solution to obtain gel; (3) stirring the gel obtained in the step (2) at 35-95 DEG C and then carrying out a crystallization reaction for 24-240 hours at 60-200 DEG C, wherein in the raw materials for synthesizing the molecular sieve, and the molar ratio of OH<-1> to SO2 to AL2O3 to H2O to the organic directing agent to the organic directing agent is (0.1-0.35):1:(0.0005-0.01):(10-25):(0.1-0.6):(0.5-8). The ZSM-5 type catalyst has the characteristics of controllable grain size, adjustable silica alumina ratio, high dispersity, and the like and has higher propylene selectivity and P / E ratio in the reaction for preparing low carbon olefin from the methanol and / or the dimethyl ether.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and relates to a ZSM-5 molecular sieve and a preparation method thereof, in particular to a small-grain ZSM-5 molecular sieve catalyst for the reaction of preparing propylene with methanol and / or dimethyl ether as raw materials and its preparation method. Background technique [0002] With the continuous development of the global economy, the demand for propylene as an important petrochemical raw material is on the rise, and the problem of propylene shortage is becoming increasingly prominent. Propylene is mainly derived from petroleum. With the sharp increase in global oil prices and the depletion of petroleum energy in the future, new propylene sources and application technology issues have attracted widespread attention. From a strategic point of view, using methanol or dimethyl ether as raw material to produce propylene (MTP or DTP) can broaden raw material channels, adjust the structure ...

AI Technical Summary

Problems solved by technology

[0005] Therefore, the object of the present invention is to provide a kind of new small grain ZSM-5 catalyst and synthetic method thereof, solve the problem that MTP or DTP reaction exists in the prior art Technical problems of low propylene selectivity and low mass ratio of propylene to ethylene (P / E)

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