A combined gasification process of circulating fluidized bed and pyrolysis bed and its device

Abstract

A combined gasification process and device of a circulating fluidized bed and a pyrolysis bed relate to coal gasification technology. The process is to use fluidized bed technology to pyrolyze and gasify, to realize the conversion of coal into gas without tar and other pollutants; to use pyrolysis bed to gasify and burn semi-coked coal, etc.; The fly ash is removed and sent back to the fluidized bed gasifier for cyclic pyrolysis and gasification by means of a screw conveyor. Combustion and transportation of raw coal, coal gas, semi-coke, and coal-containing fly ash are achieved by using interconnected fluidized bed gasifiers, cyclone separators, pyrolysis beds, and sedimentation chambers. The beneficial effect of the present invention is that: the gasification rate of raw coal is high, and the gasification process does not produce pollutants such as tar; it is suitable for equipment with various gasification capacities of large, medium and small, and the adjustment range of gas production per unit time is large.

Description

technical field [0001] The invention relates to a coal-to-gas compound gasification device, specifically a gasification furnace for sequential fluidized pyrolysis gasification of a circulating fluidized bed and a pyrolysis bed, which is used for the gasification of raw coal and belongs to the technology of coal gasification equipment field. Background technique [0002] With the rapid development of industrial economy, coal combustion has become an indispensable way to obtain heat in the process of industrial production. However, direct burning of coal will cause great pollution to the environment, so the state has issued a large number of documents about prohibiting direct burning of coal for heating in recent years. Instead, raw coal is converted into clean and pollution-free gas for combustion to obtain heat. For this reason, various gasifiers for converting raw coal into gas have been designed, such as fixed-bed gasifiers, circulating fluidized-bed gasifiers, etc. Form...

AI Technical Summary

Problems solved by technology

However, after studying the existing various forms of gasifiers, it is found that each gasifier has its own advantages and disadvantages. For example, the fixed bed gasifier has high coal conversion rate and thermal efficiency, and the coal gas contains a large amount of tar and other pollutants; Circulating fluidized bed gasifier produces clean gas without tar and other pollutants. However, the thermal efficiency of raw coal is low, and the coal slag contains a large amount of semi-coke. It is necessary to transport the coke-containing coal slag to a low-demand combustion environment for re-combustion , such as thermal feedstock for combustion in thermal power plants

On the one hand, it reduces the utilization rate of coal, on the other hand, it increases the transportation labor and other costs

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