A kind of methanation catalyst and preparation method thereof

Abstract

The invention discloses a methanation catalyst which comprises a support and active components supported on the support, wherein the support is a mesoporous molecular sieve; and the active components comprise magnesia alumina spinel, NiO, La2O3 and CeO2 and also comprise one or more of Fe2O3, TiO2, SiO2, K2O, CaO, MoO3, MnO2 and ZrO2. The preparation method of the methanation catalyst comprises the following steps: impregnating the mesoporous molecular sieve into the magnesia alumina spinel, drying, roasting to obtain a support precursor, coprecipitating the other active components, and finally, roasting to obtain the required catalyst. The active components and magnesia alumina spinel are supported on the mesoporous molecular sieve, thereby enhancing the CO2 conversion rate in every stage of reaction in the multistage methanation reaction process of coke oven gas under the interactions between the magnesia alumina spinel and active components in combination with the synergistic actions of the mesoporous molecular sieve. More CO2 in the gas mixture in every stage of reactor is converted into CH4, thereby breaking the original reaction equilibrium and promoting the conversion of CO2.

Description

technical field [0001] The invention relates to a methanation catalyst and a preparation method thereof, and belongs to the technical field of hydrocarbon industry tail gas synthesis and substitution of natural gas. Background technique [0002] Coke oven gas, also known as coke oven gas, refers to a combustible gas produced while coke and tar products are produced after high-temperature dry distillation in a coke oven by using several kinds of bituminous coal to make coking coal. A by-product of the coking industry. Coke oven gas is a mixture whose main components are hydrogen (55%-60%) and methane (23%-27%), and also contains a small amount of carbon monoxide (5%-8%), unsaturated hydrocarbons above C2 (2% ~4%), carbon dioxide (1.5%~3%), oxygen (0.3%~0.8%)) and nitrogen (3%~7%), etc. Among them, hydrogen, methane, carbon monoxide, and unsaturated hydrocarbons above C2 are flammable components, and carbon dioxide and nitrogen are non-flammable components. [0003] With th...

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Problems solved by technology

[0004] In order to solve the coke oven gas methanation reaction process in the prior art, the catalyst first catalyzes CO and H 2 A reaction occurs, resulting in CO 2 The conversion rate is not high, providing a catalyst that can simultaneously catalyze CO and CO 2 with H 2 Catalysts that react to improve the selectivity of existing catalysts

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