Coal catalytic gasification method

Abstract

The embodiment of the invention provides a coal catalytic gasification method, which belongs to the field of coal catalytic gasification and can enhance the methane yield and carbon conversion rate. The coal catalytic gasification method comprises the following steps: dividing the reactor main body into a hydrogenation pyrolysis zone, a catalytic gasification zone and a combustion zone from top to bottom according to different internal temperatures; introducing oxygen-containing gas into the combustion zone to initiate combustion reaction and gasification reaction between the oxygen-containing gas and coal in the combustion zone, thereby generating carbon dioxide, carbon monoxide and hydrogen; and introducing hydrogen into the catalytic gasification zone to inhibit the carbon monoxide from participating in water gas shift reaction, thereby promoting carbon monoxide to participate in methanation reaction. The method can be used in a coal catalytic gasification technique which utilizes a fluidized bed reactor.

Description

technical field [0001] The invention relates to the field of coal catalytic gasification, in particular to a coal catalytic gasification method. Background technique [0002] Coal catalytic gasification technology refers to the gasification technology in which coal reacts with gasification agents such as water vapor under the catalytic action of catalyst at relatively low temperature to generate high-concentration methane. Compared with other coal gasification technologies, coal catalytic gasification technology has the advantages of high methane content and low reaction temperature. [0003] Coal-to-natural gas technology was produced by a two-step process at the initial stage, but because the two-step process requires air separation, gasification, shift and methanation, the process is complicated and the investment is huge, making it unsuitable for large-scale coal production. in the natural gas process. In contrast, the one-step coal-to-natural gas technology, which use...

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Problems solved by technology

In the existing one-step technology, most of them adopt the external heat supply method, that is, a large amount of superheated steam and circulating part of the product gas carbon monoxide and hydrogen enter the gasifier to generate heat from the methanation reaction to provide the heat required by the system, but this method can High energy consumption and high investment in equipment. It is acceptable to use this method for small-scale research and development, but there is no economic advantage to achieve industrialization.

Moreover, in this method, the product gas carbon monoxide and hydrogen that are circulated will not only inhibit the gasification reaction and reduce the carbon conversion rate, but also inhibit the methanation reaction because the carbon monoxide in the main body of the reactor mainly participates in the water gas shift reaction to reduce methane yield

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