A Fluidized Bed Lignite Gasification Process with Ash Circulation

Abstract

The invention discloses a novel lignite gasification process by using a fluidized bed with ash circulation and equipment of the novel lignite gasification process. According to the novel lignite gasification process, a dried lignite raw material is put into a fluidized bed gasification furnace, a gasifying agent is put into the gasification furnace to perform mixed reaction with the lignite, a synthetic gas generated by the reaction between the lignite and the gasifying agent leaves the gasification furnace and flows to a downstream section after being separated and filtered, and separated fine powder returns to the gasification furnace through a pipeline; one part of the ash generated by lignite combustion is returned to the gasification furnace to perform further burning, and the other part of the ash is discharged from the bottom of the gasification furnace; the ash returned to the gasification furnace can be further burnt in two modes including a gas flow conveying mode and a mechanical conveying mode. According to the process disclosed by the invention, two ash circulating modes including the gas flow conveying mode and the mechanical conveying mode are used to ensure that the ash can be returned to the gasification furnace for continuous burning so as to reduce carbon residues on the ash and improve the carbon utilization ratio when the lignite raw material is converted into the synthetic gas. The process and the equipment are simple and reliable, can effectively reduce investment and increase the running reliability, and have environment-friendly effect and less in pollutant discharge.

Description

technical field [0001] The invention relates to the technical field of coal gasification, in particular to a process technology for producing producer gas, water gas and synthesis gas from solid carbonaceous materials, especially lignite. Background technique [0002] my country is rich in lignite resources, with proven reserves reaching 129.1 billion tons, accounting for about 13% of the country's coal reserves and occupying an important position in my country's coal resources. Effective utilization of lignite resources is of great significance to ensure the stable supply of energy in our country. However, due to the high moisture content, low calorific value, and poor thermal stability of lignite, it is not suitable for long-distance transportation, and it has great limitations as a raw material for large-scale gasification. At present, it is only used as a power fuel in some areas, and the development rate is low. , currently only accounts for 4-5% of the country's coal ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problems of low efficiency of converting carbon into synthesis gas and relatively complicated process in the above lignite gasification, the present invention overcomes the factors that the ash content of lignite is in a solid state, which is not easy to circulate, and the fact that the lignite gasification equipment is in a high temperature state is unfavorable to ash circulation. , developed a new type of ash circulation fluidized bed lignite gasification process and its equipment, this invention can make the ash discharged from the gasification furnace return to the gasification furnace to continue burning, so that the carbon conversion efficiency can reach more than 99%

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