Method and device for detarring small-sized biomass gasifier

Abstract

The invention discloses a method and a device for detarring a small-sized biomass gasifier. The device comprises a furnace body, an air preheating chamber, an external furnace catalyzing chamber, a purifying chamber, a separating chamber, a tar recycling pipe, an internal furnace cracking pipe and the like. The method comprises the following steps that: coarse fuel gas flows into the catalyzing chamber arranged outside the furnace from a furnace outlet; partial tar is catalytically cracked, and then enters the purifying chamber and the separating chamber; the separating chamber is internally provided with a baffling plate, and the outer wall is provided with longitudinal fins; the fuel gas exchanges heat with air in the air preheating chamber when flowing; and the tar continuously condensing and water flow into the recycling pipe provided with a U-shaped liquid sealing section along the wall of the purifying chamber, and then circularly flow into a semi-arc catalytic cracking pipe positioned in a high-temperature oxidation zone of the gasifier. The preheated air can obviously increase the temperature of the internal furnace oxidation zone, which is greatly favorable for fully carrying out tar catalytic cracking reaction in the pipe, and the tar flows into a furnace hearth through exhaust holes on the pipe wall. The method and the device can realize the secondary catalytic cracking and separation recycling of the tar, obviously improve the gasifier efficiency and the fuel gas calorific value, and have the advantages of small system flow resistance and easy implementation.

Description

Technical field [0001] The invention relates to a gasification furnace, in particular to a method for purifying tar in crude gas of a small-scale biomass gasification furnace and its device structure. Background technique [0002] The application of existing small biomass gasifiers in rural areas is mainly used as a gas source for the cooking gas of scattered users. Since tar is an inevitable by-product of the gasification process, taking the above suction gasifier as an example, tar often accounts for 5-15% of the total energy of crude gas. If the tar cannot be effectively purified, when the gas temperature is lower than 200℃ When tar is easy to condense into liquid and block gas pipelines, valves, stoves, etc., it not only seriously affects the long-term stable operation of the gasification device, but also reduces the gasification efficiency of the biomass gasifier and causes pollution to the environment. At present, due to the simple structure of the purification device...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the common problems of high tar content, low gas calorific value and unstable operation in existing small-scale biomass gasification furnaces, and provide a gasification agent (air ) preheating, gasification furnace with improved calorific value of gas and method and device for removing tar

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