Molecular sieve catalyst and preparation method and application thereof

Abstract

The invention provides a molecular sieve catalyst, which is prepared from the following components in parts by weight: 50 to 80 parts of a hydrogen type ZSM-5 molecular sieve, 1 to 10 parts of inorganic fibers and 5 to 40 parts of SiO2. The invention further provides a method for preparing the molecular sieve catalyst, which comprises the steps of (1) uniformly mixing a hydrogen type ZSM-5 molecular sieve, inorganic fibers, a precursor of a silicon dioxide adhesive and a forming additive, and then forming; (2) drying the intermediate product obtained in the step (1) in the shade at room temperature, then drying, and then roasting; (3) carrying out ammonium ion exchange on the intermediate product obtained in the step (2); and (4) drying the intermediate product obtained in the step (3), and roasting to obtain the molecular sieve catalyst. The invention also provides an application of the molecular sieve catalyst or the molecular sieve catalyst prepared by the method in preparation of propylene by methanol conversion. The catalyst provided by the invention has good activity and propylene selectivity, and also has high-temperature burst resistance.

Description

technical field [0001] The invention belongs to the technical field of catalysts. Specifically, the present invention relates to a molecular sieve catalyst and its preparation method and application. Background technique [0002] The process of producing methanol from coal or natural gas raw materials, and then converting methanol to propylene (MTP) is an important non-petroleum route to produce propylene. The MTP reaction is generally carried out under the catalyst of zeolite molecular sieve. At present, the more recognized reaction mechanism is "carbon pool mechanism". It is believed that the reaction process includes three key steps: methanol dehydration to generate dimethyl ether; CH 2 ) n Generate olefins; olefins are converted into aromatics and alkanes through processes such as polymerization, hydrogen transfer, alkylation, cracking, isomerization, and cyclization. Among them, the fixed-bed MTP process adopts ZSM-5 molecular sieve catalyst, the reaction temperatur...

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Problems solved by technology

[0004] Since the MTP catalyst has been in the cycle of "reaction-coking deactivation-charcoal regeneration" throughout its life cycle; on the other hand, the process of converting methanol to propylene is a process of increasing the number of molecules, and low pressure is conducive to improving the propylene Yield; on the other hand, the crushing and powdering of the catalyst may bring difficulties to the normal operation of the device, and in severe cases, it will cause shutdown

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