Method for automatically removing tar oil from fixed-bed biomass gasification furnace

Abstract

The invention provides a method for automatically removing tar oil from a fixed-bed biomass gasification furnace. The lower section of the gasification furnace produces biomass gas, the upper section of the gasification furnace is provided with a gas channel, the space in the gas channel is cooled, and the temperature of the gas produced by the lower section of the gasification furnace is reduced when the gas passes through the gas channel from bottom to top, so that tar oil in the gas is separated out. According to the method, the production efficiency of the gas is not influenced, and no pollution is caused to an external environment and circulating water; one part of the heat produced by gas cooling is used for drying fuel on a drying layer in the furnace, so that little heat is taken away through cooling of the circulating water; during cooling of the gas, a great amount of tar oil is recycled and participates in gasification again, so that the energy utilization rate is greatly improved, and the saved heat is more than the lost heat caused by cooling; and furthermore, as the temperature of the gas is low, the requirement on an auxiliary machine, an instrument, pipelines and the like is greatly reduced, and thus the investment cost is saved.

Description

technical field [0001] The invention relates to a method for self-removing tar used in a biomass fixed-bed gasifier. Background technique [0002] Biomass is a very important renewable energy, which has the characteristics of renewability, low pollution and wide distribution. The use of biomass as an alternative energy source is of great significance to low-carbon emission reduction, reduction of "greenhouse effect" and improvement of atmospheric acid rain environment. Biomass gasification system is to use biomass to burn in a closed anoxic furnace in a gasifier, and produce combustible gas after dry distillation, pyrolysis and thermochemical oxidation. [0003] Fixed bed gasifier is an important type of biomass gasification system. In a fixed-bed gasifier, the fuel exists in a piled state in the furnace, and the gasification process is completed by layer combustion. Because the fuel pyrolysis time of the fixed-bed gasifier is longer and the pressure is more, the tar cont...

AI Technical Summary

Problems solved by technology

[0007] In the above technical solution, external tar removal is adopted, and the tar precipitated by external water washing is discharged into the environment together with water, causing pollution to the circulating water and deterioration of the working environment, and causing serious pollution to the external environment

[0008] However, increasing the gas temperature by increasing the secondary and tertiary air is actually at the cost of sacrificing the calorific value of the gas, and increasing the gas temperature greatly increases the requirements for gas pipelines and subsequent equipment, and the cost will also increase accordingly. If the road is extended, the gas will inevitably cool down. Once the temperature cools down, tar will be produced.

[0009] These two technologies solve the tar problem under the premise of sacrificing the environment, investment cost (equipment service life) or output efficiency, and both have very obvious defects

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