Method and device for preparing low-tar combustible gas through biomass gasification

Abstract

The invention discloses a method and a device for preparing a low-tar combustible gas through biomass gasification. The method comprises the followings steps of: pulverizing and gasifying biomass, and rapidly separating obtained gasification gas products and biomass char; heating and activating the biomass char in a microwave field; catalytically cracking tar in the gasification gas products by introducing the gasification gas products to pass through a treated biomass char layer, and carrying out secondary reaction on the gasification gas and the biomass char to produce the combustible gas. The device comprises a spiral-flow gasifier 1, a fixed bed reactor 2 and a microwave generator 3 which are connected through ducts, and the middle part of the fixed bed reactor is connected with the microwave generator 3 through a microwave duct 11. The microwave technology is applied to tar cracking, so that the problem of low heat transfer speed due to porous and loose biomass char is solved. Meanwhile, the cracking rate of tar and the secondary reaction activity between the char and the gasification gas are increased by using the 'hot spot effect' of microwaves. The device has the advantages of strong adaptability, simple and compact structure and easy enlargement.

Description

technical field [0001] The invention relates to the technical field of biomass energy utilization, in particular to a method and device for producing combustible gas with low tar content through biomass gasification. technical background [0002] Energy crisis and environmental pollution are dual challenges facing the world today, and the rational use of biomass energy is an effective way to solve this problem. Biomass gasification can directly meet the needs of heat supply, power generation and synthetic chemical industry, which is an important direction for the development of biomass energy. In biomass pyrolysis gasification technology, tar is an inevitable by-product. The existence of tar has many adverse effects. For this reason, many researchers have proposed different methods for the treatment of tar. The catalytic cracking technology of tar can not only effectively reduce the tar content in gasification gas, but also make full use of the energy of tar. It is more ad...

AI Technical Summary

Problems solved by technology

The pyrolysis reaction speed of this method is slow, and the reactivity of the carbon layer is not high at the same time, so that the equipment processing efficiency is not high

[0004] None of the above patents involve the use of microwaves to activate biomass coke and catalytically active substances in the coke produced by biomass gasification to promote secondary reactions, crack gasification tar, and produce low-tar content combustible gas

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