Biomass pyrolysis gasification method and system

Abstract

The invention discloses a biomass pyrolysis gasification method and system.The method comprises the steps that firstly, a biomass raw material is subjected to rapid heating treatment, and the biomass raw material with the surface carbonized is obtained after treatment; and then feeding the surface-carbonized biomass raw material into a microwave pyrolyzer for gasification reaction to obtain a synthesis gas product and solid residues after the reaction. The biomass pyrolysis gasification system comprises a preprocessor, a microwave pyrolyzer, a gas-solid separation unit and a heat carrier regenerator. According to the method, firstly, biomass raw materials are pretreated, the outer surfaces of the biomass raw materials are subjected to rapid carbonization treatment to form a carbon layer, pyrolysis volatile components released from inside to outside in the subsequent microwave pyrolysis gasification process can be subjected to cracking and reforming reaction with the formed carbon layer, endogenous power formed by tar is inhibited from the source, and the biomass raw materials can be recycled. The biomass pyrolysis gasification efficiency is improved, the economical efficiency of the process is improved, and the method has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of biomass energy, in particular to a biomass microwave pyrolysis gasification method and system. Background technique [0002] The conversion of biomass into high-quality gaseous fuels by pyrolysis is an important way to achieve efficient utilization of biomass. Compared with conventional gasification technology, pyrolysis is thermal conversion under anaerobic or oxygen-barrier conditions, which avoids the introduction of exogenous gases and is conducive to obtaining biomass gas with higher calorific value and higher hydrogen-to-carbon ratio. However, in the actual application process, the method of biomass pyrolysis often produces more tar, and the tar is poor in stability, easy to coke and corrode, resulting in the problem of gas blockage and loss in the pyrolysis process. Aiming at the problem that it is difficult to remove tar in pyrolysis gas, most of the current research adopts two removal processes,...

AI Technical Summary

Problems solved by technology

However, in the actual application process, the method of biomass pyrolysis often produces more tar, and the tar has poor stability and is easy to coke and corrode, resulting in the problem of gas blockage and loss in the pyrolysis process

Aiming at the problem that it is difficult to remove tar in pyrolysis gas, most of the current research adopts two removal processes, inside the reactor and outside the reactor. The removal of tar outside the reactor is a relatively mature method, which has higher catalytic activity by setting Active metal catalysts such as nickel, iron, cobalt, palladium, rhodium, and lanthanum are used to remove tar oil online, but this method has the problems of high catalyst cost and limited recycling performance, and it is difficult to apply it on a large scale in a short time

The process of removing tar in the reactor usually adds cheap catalysts with catalytic cracking function during the biomass pyrolysis process, such as biocoke, alkali metal and natural ore, etc. This method can significantly reduce the tar content in the gas , but there are also problems such as large dosage and difficulty in recycling. From the perspective of practical application, the detarring route in the reactor still has a good development prospect because of its low cost and easy maintenance.

[0003] In order to solve the problem of difficult removal of tar in the reactor, Chinese invention patent 20191092072.3 discloses a method for reducing the tar content in the synthesis gas of a biomass fluidized bed gasifier, using fly ash loaded with calcium oxide as bed material and gasification The tar in the furnace is catalytically cracked, which effectively reduces the tar content and rationally utilizes the gasification slag, but how to realize the recycling performance of the bed material is still an important technical problem in the promotion of this method

Aiming at the difficulty of recycling catalysis in the reactor, Chinese invention patent 201910038001.8 provides a biomass circulating fluidized bed graded pyrolysis gasification and high-temperature tar removal and dust removal integrated process, through gas and pyrolysis semi-coke and heat carrier Fractional separation, the small and medium particle heat carrier and pyrolysis semi-coke are directly circulated back to the fluidized bed to participate in tar cracking, and the large particle heat carrier and pyrolysis semi-coke are used as a high-temperature moving bed for the removal of residual tar, which effectively solves the problem of reactor Problems with the use of internal catalysts

However, the catalyst regeneration and biomass gasification are realized in the same process, which means that a large amount of combustible gas is introduced into the biomass gas production process, which has a great impact on the calorific value of the gas and is not conducive to obtaining high-quality gas

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