Core-shell structure multi-level porous cobalt-based Fischer-Tropsch synthesis catalyst and preparation method thereof

Abstract

Provided are a multi-level channel-type cobalt-based Fischer-Tropsch synthetic catalyst with a core-shell structure and a preparation method therefor. The catalyst comprises a catalyst carrier S, a metal active component Co loaded on the catalyst carrier S and a shell layer molecular sieve membrane M which wraps the surface of the catalyst carrier S, wherein the catalyst carrier S is one of or a mixture of two of SiO2 and Al2O3 in any proportion, the microstructure morphology of SiO2 and Al2O3 is spherical, the specific surface area thereof is 160-290 m2 / g, and the average particle size ranges between 10 and 50 meshes; the shell layer molecular sieve membrane M is a cluster aggregate of uniformly dispersed H-ZSM-5 nanoparticles, the particle size of the H-ZSM-5 nanoparticles ranges between 10-30 nm, the micropore aperture thereof is less than or equal to 2.0 nm, and the gap between adjacent H-ZSM-5 nanoparticles is less than or equal to 100 nm; and the loading amount of the metal active component Co accounts for 10-30% of the sum of the weights of the catalyst carrier S and the metal active component Co. The shell layer of the Fischer-Tropsch synthetic catalyst has a multi-level channel and a high catalytic efficiency. Meanwhile, the preparation method is simple in process and low in energy consumption.

Description

technical field [0001] The invention belongs to the technical field of Fischer-Tropsch synthesis, and specifically refers to a core-shell structure multi-stage channel type cobalt-based Fischer-Tropsch synthesis catalyst and a preparation method thereof. Background technique [0002] The Fischer-Tropsch synthesis reaction refers to the synthesis of coal, natural gas, biomass and other resources through synthesis gas (CO and H 2 ) Catalyzed conversion into hydrocarbons. The products of Fischer-Tropsch synthesis are sulfur-free, nitrogen-free and aromatic-free, so the liquid fuels generated by Fischer-Tropsch synthesis can meet the increasingly stringent environmental protection requirements. key raw material. Therefore, the Fischer-Tropsch synthesis reaction is one of the important ways for the indirect conversion of non-oil-based resources to high-quality liquid fuels and chemical raw materials. Low-carbon olefins are important organic chemical raw materials, and their pr...

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Problems solved by technology

However, the limitation of the micropores of the molecular sieve membrane in this method leads to an extremely low CO conversion rate of only about 40%.

Moreover, neither of the above two methods can solve the problem that the molecular sieve pore size distribution is too concentrated in the micropores, resulting in a decrease in conversion rate.

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