Sulfur-tolerant methanation catalyst and preparation method thereof as well as magnesium aluminate spinel composite carrier and preparation method thereof

Abstract

The invention relates to the field of catalysts, and discloses a sulfur-tolerant methanation catalyst and a preparation method thereof as well as a magnesium aluminate spinel composite carrier and a preparation method thereof. The sulfur-tolerant methanation catalyst comprises a magnesium aluminate spinel composite carrier, a catalyst active component and an optional catalyst aid, wherein the catalyst active component is loaded by the magnesium aluminate spinel composite carrier; the magnesium aluminate spinel composite carrier is a carrier of a core-shell structure formed by a carrier modifier as a shell layer and magnesium aluminate spinel as a core layer; and relative to 100 parts by weight of the magnesium aluminate spinel, the amount of the catalyst aid is 0-20 parts by weight, the amount of the catalyst active component is 5-30 parts by weight, and the amount of the carrier modifier is 2-15 parts by weight. By adopting the sulfur-tolerant methanation catalyst disclosed by the invention, the CO (Carbon Monoxide) transformation rate is increased, the methane selectivity is improved, the reaction stability and the high-temperature catalysis property stability are also improved, the service life of the catalyst is prolonged, and meanwhile the amount of the carrier modifier and the production cost of the catalyst are reduced.

Description

technical field [0001] The invention relates to the field of catalysts, in particular to a sulfur-resistant methanation catalyst and a preparation method thereof, a magnesium-aluminum spinel composite carrier and a preparation method thereof. Background technique [0002] The methanation reaction refers to the reaction of CO in the synthesis gas with H under the action of certain temperature, pressure and catalyst. 2 The process of reacting to form methane. Its reaction formula can be expressed as follows: [0003] CO+3H 2 =CH 4 +H 2 O (1) [0004] CO+H 2 O=CO 2 +H 2 (2) [0005] 2CO+2H 2 =CH 4 +CO 2 (3) [0006] It is generally believed that the methanation reaction of syngas is one of the best solutions for the clean utilization of coal. Syngas is mainly obtained from coal gasification or coal pyrolysis. The synthesis of methane can be achieved by contacting the catalyst. Methanation can not only reduce the greenhouse gas emissions and environmental polluti...

AI Technical Summary

Problems solved by technology

However, in this application, the aluminum-magnesium spinel precursor and the carrier modifier precursor cannot form a composite porous carrier with a core-shell structure by coprecipitation, kneading or sol-gel methods; Only part of the core-shell structure can be formed, and a considerable proportion of the carrier modifier will enter the pores of the Al-Mg spinel porous carrier instead of the carrier surface, which leads to a very high amount of carrier modifier, reaching 5% -90%, non-core-shell structure or partial core-shell structure will affect the strength of the formed catalyst, which in turn affects the high temperature stability of the catalyst

[0012] That is, the catalytic performance of the sulfur-resistant methanation catalyst disclosed in the prior art has poor high-temperature stability. After the catalyst is used at high temperature for a short period of time, its catalytic performance often deteriorates rapidly, which will lead to shortened catalyst life. At the same time, Raw materials for the production of the above catalysts such as CeO 2 etc. are expensive, therefore, it is impossible to achieve a good balance and balance between performance and production costs.

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