Preparation methods for bifunctional catalyst and low-carbon-chain olefin

Abstract

The invention relates to preparation methods for a bifunctional catalyst and low-carbon-chain olefin. The preparation method for the bifunctional catalyst comprises the following steps: preparation ofan SAPO-34 molecular sieve carrier with a multistage pore channel: a step of preparing an initial gel mixture, subjecting the initial gel mixture to crystallization treatment, introducing mixed gas of acetylene and hydrogen in the process of crystallization treatment, carrying out repeated inflation and deflation, carrying out stamping to a predetermined pressure so as to obtain SAPO-34 molecularsieve raw powder, and calcining the SAPO-34 molecular sieve raw powder so as to obtain the SAPO-34 molecular sieve carrier; and loading active components and a cocatalyst onto the SAPO-34 molecular sieve carrier for preparation of the bifunctional catalyst. The preparation method for the low-carbon-chain olefin comprises the following steps: mixing acetylene and hydrogen in proportion, and allowing mixed gas to react in presence of the bifunctional catalyst at 100 to 150 DEG C. According to the invention, through a special crystallization treatment method, the SAPO-34 molecular sieve raw powder is obtained, and the bifunctional catalyst is also prepared and has double active centers, so one-step preparation of the low-carbon-chain olefin can be realized; meanwhile, a product has high selectivity.

Description

technical field [0001] The invention relates to the technical field of catalyst and olefin preparation, and more specifically, relates to a multifunctional catalyst and a method for preparing low-carbon olefins. Background technique [0002] Low-carbon olefins generally refer to olefins with 4 or less carbon atoms, such as ethylene, propylene, and butene. Low-carbon olefins are the most basic raw materials for petrochemical production, and can be used to produce organic compounds such as polyethylene, polypropylene, acrylonitrile, ethylene oxide or ethylene glycol. There are two main methods for preparing low-carbon olefins: one is the petroleum route; the other is the non-petroleum route. my country's oil resources are relatively scarce, and coal and natural gas resources are relatively rich. Based on our energy structure, the development of coal chemical and natural gas chemical technology is in line with our national conditions. At present, the feasible technical routes...

AI Technical Summary

Problems solved by technology

At present, there are few studies on the preparation of low-carbon alkenes based on acetylene polymerization and hydrogenation, especially the preparation of ethylene and butadiene.

[0003] In the prior art, butadiene is synthesized using a silica gel-supported palladium-lead bimetallic catalyst, and the coke produced by the reaction is likely to block the pores of the catalyst and deactivate the catalyst; and the required reduction temperature is relatively high, about 400°C

And the catalyst contains lead element, the follow-up treatment is difficult

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