Process and equipment for co-gasification of biomass and coal

Abstract

This invention relates to a biomass and coal mixing gasifying generating low heat value fuel gas in fluidized-bed technique and its equipment. In this method air is main part and few pure water gases are added as gasification agent. The air is 1.2-2.0m3 / Kg in coal and biomass charging gross, but water gas is 0.2-0.3Kg / Kg. the gasification material is 0-10mm powder material biomass and 0-6mm powder coal. The ratio of biomass and coal is between 40 / 60-80 / 20. the two materials are added into biomass fluidized-bed gasification furnace by two different special using feeder, the work temperature is 850-950 degrees centigrade, fluidizing velocity is 0.8-1.2m / s. the crude fuel gas is dust removed through high temperature cyclone separator, the dust contain coal powder after separated is filled into dust stock tank though lay off pipe. The fuel gas temperature cools down to 300 degrees centigrade after high temperature cyclone separator dust removing. Then it enters purification system for further washing and dust removal, and then it is sent to gas receiver. It is non tar and technique is simple.

Description

technical field [0001] The invention relates to energy equipment, in particular to a gasification process and its device for generating low calorific value gas by mixed gasification of biomass and coal in a fluidized bed. Background technique [0002] The existing biomass fluidized bed gasifier with air as the gasification agent is widely used in industry for power generation and heat supply because of its simple process, low investment, low operating cost, and convenient operation. Due to the small bulk density of biomass, low ash content, high volatile content, low fixed carbon content, and high gasification reactivity, biomass is easy to gasify, but it is difficult to form a stable fluidized material layer. The solution at home and abroad is to fluidize A certain amount of inert particles such as river sand, quartz sand, etc. are added to the bed to establish a stable material layer. Moreover, due to the high volatile content of biomass and low reaction temperature, gene...

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Problems solved by technology

Moreover, due to the high volatile content of biomass and the low reaction temperature, generally 700-750°C, high-molecular hydrocarbons cannot be cracked into gaseous small molecules, and the product gas contains a large amount of tar, which seriously affects the use of gas

At present, the method of catalytic cracking is used to remove the tar in the gas at home and abroad, but for small and medium-scale biomass gasification plants, there are many problems in terms of economy and operation.

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