Biomass and coal fluidized bed co-gasification method

Abstract

The invention discloses a biomass and coal fluidized bed co-gasification method. The method comprises the following steps: biomass and coal are crushed and mixed to form biomass-coal mixture, the biomass-coal mixture is added to a fluidized bed gasification outer barrel and is gasified under the effect of a gasifying agent, and gas generated by gasification reaction is discharged through a cyclone separator; meanwhile, the biomass-coal mixture is added to a combustion inner barrel, coal coke which is not gasified in the gasification outer barrel and the entered compressed air are subjected to combustion reaction, and then ascend along the gasification inner barrel; and the coal coke enters an inertia separator to be gasified circularly along with a combustion gas flow, high-temperature flue gas and the biomass-coal mixture are subjected to countercurrent heat exchange and are discharged by a cyclone separator, and ash residue is discharged from the bottom. According to the biomass and coal fluidized bed co-gasification method, the gasification process and the combustion process of the biomass and coal are separated, the circulation of high-temperature material provides heat for the gasification reaction, heat is also directly exchanged through the thermal radiation and convection of a combustion chamber and a gasification chamber, the heat loss is reduced, meanwhile the production efficiency is improved, and the heat value of synthesis gas is high.

Description

technical field [0001] The invention relates to a coal fluidized bed gasification method, in particular to a co-gasification method of biomass and coal fluidized bed. Background technique [0002] In the present invention, biomass refers to lignocellulose (referred to as lignin) such as straw and trees other than grain and fruit in the agricultural and forestry production process, leftovers from agricultural product processing industry, agricultural and forestry waste, and the waste produced in the animal husbandry production process. Substances such as poultry manure and litter. [0003] In most rural areas, the traditional way of life energy harvesting is continued, and agricultural and forestry wastes such as straw and sawdust are directly burned without processing, and the conversion efficiency is only 10% to 15%, which is inconvenient, unhygienic, and environmentally friendly. The benefits are poor. Biomass energy, as a renewable clean energy, can realize CO 2 Zero e...

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Problems solved by technology

Compared with the intermittent operation methods of air combustion and steam gasification, this method is simple to operate and improves production efficiency, but the composition of the generated syngas is complex, and the proportion of CO2 gas in the product is biased. High, less active ingredients

[0009] The third category is the process of indirect gasification of biomass and coal fluidized bed, such as the patent document "Double fluidized bed solid fuel" with publication number CN 102199450 A Gasification combustion coupling method and system", the gasification process and the combustion process are carried out in two fluidized beds respectively, and the endothermic gasification reaction and the exothermic combustion reaction are completed in the same device through the circulation system, which can obtain high purity Syngas, but due to the separation of the combustion process and the gasification process, the heat transfer is only realized by the circulation of the flowing material between the combustion furnace and the gasification furnace, which is lower than the direct heat radiation or convective heat transfer efficiency in direct gasification. large heat loss

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