Dry slagging high-temperature entrained flow gasification method

Abstract

The invention discloses a dry slagging high-temperature entrained flow gasification method, which relates to the technical field of energy and chemical industry. By adopting the key technology of 'controlling gasification combustion manner and gasification temperature, and obtaining synthesis gas through dry slagging', the method pyrolyzes raw materials of biomass to obtain carbon and pyrolysis gas; carbon powders formed by grinding the carbon are conveyed to an entrained flow by the pyrolysis gas / other gases; the carbon powders and the pyrolysis gas are conveyed to the entrained flow and simultaneously conduct mixed suspension combustion gasification with oxygen serving as an oxidizer; during the process of gasification, direct-flow jet streams surrounding the carbon powders are arrangedon the periphery of a carbon powder inlet entering the entrained flow, the outlet temperature of the entrained flow ranges from 1250 DEG C to1350 DEG C, the highest temperature of the furnace wall ofthe entrained flow is lower than ash fusion point of the raw materials by above 50 DEG C, thereby enabling ash particles to be solid particles when at positions close to the furnace wall of the entrained flow, a slagging hole and a synthesis gas outlet so as to obtain the synthesis gas under the premise of the dry slagging. The dry slagging high-temperature entrained flow gasification method is applied to biomass gasification and changes the biomass to wealth so as to develop new energy and protect environment.

Description

technical field [0001] The high-temperature entrained-bed gasification method for solid-state slagging of the present invention relates to the technical field of energy and chemical engineering; in particular, it relates to the technical field of thermochemistry of biomass; Background technique [0002] The invention is especially suitable for the high-temperature gasification method for producing refined synthesis gas from renewable solid fuels such as biomass and garbage with high volatile content, low ash content and high ash melting point. The method belongs to the production and synthesis of solid carbon-containing raw materials. Gas or combustible gas technical field, wherein synthesis gas refers to the gas containing CO, H 2 And various mixtures of carbohydrate gases containing carbon, hydrogen, and oxygen. And the refined syngas produced by the present invention refers to: CO and H in the mixture of the syngas directly obtained by gasification 2 As the main compone...

AI Technical Summary

Problems solved by technology

However, entrained bed gasification has strict restrictions on the particle size of raw materials. The raw materials entering the entrained bed need to be ground into ultrafine particles. Grinding to meet the particle size required for entrained bed operation, which leads to the inability to directly use biomass raw materials for entrained bed gasification

Second, all the current entrained bed gasification technologies in the world adopt the liquid slagging method like pulverized coal gasification, and / or generally control the outlet temperature of the syngas above 1500°C, and the ash of the raw material is gasified It is melted in the furnace and flows to the slag pool along the furnace wall. The purpose is to reduce the ash content in the synthesis gas. Although this technology is widely used in pulverized coal gasification with low ash melting point, it also has relatively low oxygen consumption. high, the formation of a uniform liquid slag film on the wall of the entrained bed furnace is difficult, and there are even bigger problems in the gasification of biomass. First, the ash content of biomass is generally very low, such as fuel wood, straw, etc. Between 2% and 10%, this technology cannot form a uniform and stable liquid slag film on the wall of the gasifier (entrained flow bed), and it is easy to cause damage to the refractory material of the furnace wall. It is difficult to form a liquid film in the gasifier when the temperature is higher than 1400°C

Currently available biomass entrained bed gasification technologies, such as the Chinese patents with application numbers 2006101245707 and 2006101245711, and the Carbon-V gasification technology of German Kelin Company, although they are all entrained bed gasification technologies for biomass, but The above-mentioned problems are easily caused by the liquid slagging method of the gasifier

[0008] It can be seen from the above that in the existing biomass or carbon-containing solid fuel gasification technology, its deficiencies, defects and disadvantages are: none of them can achieve the purpose of obtaining refined synthesis gas through biomass gasification with high efficiency and low cost

Namely: Even if the separation method of pyrolysis and gasification is implemented for biomass, and high-temperature entrained bed technology is applied, due to the lack of good consideration of the raw material characteristics of biomass, liquid exhaust gasification similar to pulverized coal gasification is adopted. In the slag method, to form the furnace wall liquid film of the entrained bed, it is easy to cause the unreacted carbon particles to adhere to the wall, the oxygen consumption is high, and the carbon conversion rate is reduced, the gasification efficiency is low, and the gas flow of the liquid slag discharge The bed structure is complex and the investment is high

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