Patent ID: 8029581

Claim:
A method for producing coal gas, comprising: step a: feeding raw material pulverized coal and a high temperature gasification agent into a coal gas producer for reaction to produce coal gas; step b: performing a high temperature dry separation processing on the coal gas and sending pulverized coal separated from the coal gas back to the coal gas producer; step c: performing heat exchange between the separated coal gas coming from step b and a gasification agent to produce the high temperature gasification agent; step d: performing a low temperature dry separation processing on the coal gas coming from step c and sending pulverized coal separated from the coal gas coming from step c back to the coal gas producer; step e: performing heat exchange between the separated coal gas coming from step d and water to produce vapor, wherein the vapor as a component of the gasification agent is sent back to step c for heat exchanging; and step f: after heat exchange with the water and after further dust removal and desulfurization, outputting the coal gas; wherein the high temperature gasification agent is fed through three locations of the coal gas producer; the first one of the three locations is at the lower part of the coal gas producer, where the input amount of the high temperature gasification agent is 50%-60%; the second location is at the middle part of the coal gas producer, where the input amount of the high temperature gasification agent is 35%-45%; and the third one is at the middle part of the coal gas producer, where the pulverized coal separated from the coal gas in step b is fed, the pulverized coal separated from the coal gas in step d is fed, and 3%-6% of the high temperature gasification agent is fed.