Fluidized bed process and device for preparing methane by synthetic gas

Abstract

The invention relates to fluidized bed process and device for preparing methane by a synthetic gas, belonging to the field of chemical industry technologies and equipment. The process comprises the following steps: adding catalyst and diluent into a fluidized bed reaction vessel; heating and reducing the catalyst; charging the synthetic gas into the fluidized bed reaction vessel; charging a cooling medium into a reaction vessel heat exchange component to remove reaction heat; separating to obtain a methane product; and selectively containing the online replacement of the catalyst according tothe service life of the catalyst. The fluidized bed device comprises a reaction vessel simplified body, a raw gas inlet, a gas distributor, a heat exchange component, an expanding section, a cyclone separator, a catalyst feed opening and a gas outlet and selectively comprises a catalyst recovering machine and a gas stripping machine, and the reaction vessel can be divided into at least two stages.The invention has the advantages of good heat removing ability, uniform bed layer temperature, online replacement of the catalyst, high conversion rate and selectivity, long continuous running time of the catalyst, and the like.

Description

technical field [0001] The invention relates to a process and device for producing methane by using synthesis gas, in particular to a process and equipment for producing methane by using a fluidized bed process, and belongs to the technical field of chemical technology and equipment. Background technique [0002] So far, my country's economically recoverable coal reserves are 114.5 billion tons, accounting for 13.9% of the world's similar reserves. Coal is also the main body of primary energy consumption in my country's energy consumption structure, accounting for 70.2%. However, my country's coal resources are concentrated in remote areas in the central and western regions, and the transportation capacity and process economy are the factors that restrict the direct utilization of coal. Therefore, it is of great economic significance to convert coal efficiently into new chemical processes and technologies that can be easily transported through pipelines. Compared with other...

AI Technical Summary

Problems solved by technology

In the methanation of syngas, due to the high concentration of reactants, fast reaction speed, and large heat release, if the reaction temperature is low, it will be difficult to control the bed temperature due to the small heat transfer temperature difference.

In addition, due to the low temperature, high-quality steam cannot be produced, and the utilization of reaction heat is limited

[0006] 2. Using a fixed bed reactor, the heat transfer capacity is poor, and the partial methanation of water gas can still meet the heat transfer requirements, but for the complete methanation process of synthesis gas, due to the large heat release, it is difficult for the fixed bed to effectively remove the heat of reaction And the bed temperature is controlled, and the industrial scale-up of the experimental reactor is impossible. However, the methanation is carried out by connecting multi-stage fixed-bed reactors in series. The process is complex, the energy utilization is low, and there are disadvantages of large equipment investment and low energy efficiency.

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