Method and device for preparing methane-containing gas by using coal

Abstract

The invention discloses a method for preparing a methane-containing gas by using coal, which comprises the following steps that: a. pulverized coal is added to a coal pyrolysis area of a gasifier which sequentially comprises the coal pyrolysis area and a catalytic gasification area from top to bottom, and in the coal pyrolysis area, the pulverized coal is in contact with a gasification product stream from the catalytic gasification area to at least partially pyrolyze the pulverized coal to form a methane-containing gas stream and at least partial pyrolyzed pulverized coal; b. the at least partial pyrolyzed pulverized coal is sent to the catalytic gasification area and is in contact with a gasifying agent introduced into the catalytic gasification area under the action of a catalyst, the generated gasification product stream flows upwardly into the coal pyrolysis area, and fully unreacted coal residue is discharged out of the catalytic gasification area; and the gasifying agent comprises water vapor, hydrogen and carbon monoxide. The invention also discloses a device for preparing the methane-containing gas by using coal, and the device uses the method.

Description

technical field [0001] The invention relates to the field of coal gasification to prepare substitute natural gas, in particular to a method and equipment for preparing methane-containing gas by gasifying coal with a pressurized two-stage gasifier. Background technique [0002] my country is a country rich in coal, poor in oil and little in gas. With the rapid development of society and economy, the demand for natural gas in my country has risen sharply, and its proportion in the energy structure has increased rapidly. However, domestic natural gas is still in the early stages of exploration and development, imports are also in the initial stage, and the supply capacity is seriously lagging behind, resulting in increasingly prominent contradictions between natural gas supply and demand. The use of coal, which has relatively large resource advantages in my country, can not only promote the efficient and clean utilization of coal; but also use the existing natural gas pipelines...

AI Technical Summary

Problems solved by technology

However, the utilization rate of the reaction volume in the gasifier is low, which affects the solid-phase processing; only using superheated steam as the gasification agent results in a low carbon conversion rate, so the carbon content in the residue is high, and the coal is difficult to be effectively utilized; in this method The heat in the high-temperature gas needs to be transferred to the pulverized coal and steam through the tube wall of the serpentine coil. Compared with the gas-solid contact heat transfer, this indirect heating method has a slow heat transfer rate and low thermal efficiency, and the solid phase in the bed is not heated. average; at the same time, the equipment is complicated, especially the horizontal furnace

Images