Systematic device and method for biomass microwave pyrolysis poly-generation by adopting combined washing and baking pretreatment

Abstract

The invention discloses a systematic device and a method for biomass microwave pyrolysis poly-generation by adopting combined washing and baking pretreatment. The systematic device comprises a biomass washing-baking-pyrolysis system and a washing liquor circulatory system. According to the method, firstly, biomass raw materials are washed to remove part of alkali metal and impurities and then pre-dried, then large quantities of hemicellulose components are decomposed through baking pretreatment, the physical microstructure of biomass is improved, and the quality of a biomass microwave pyrolysis product after pretreatment is improved; the obtained biomass has high char calorific value and ash fusion point, low bio-oil water content and acidity, stable chemical composition, high syngas calorific value and great follow-up utilization potential. Energy of volatile matters is recovered and taken as a pre-drying heat source; meanwhile, the washing liquor circulatory system recovers sensible heat of pyrolysis char and moisture and latent heat in exhaust gas of flue gas after drying, the energy efficiency of the system is high, exhaust gas is not discharged in an operation process, operating parameters can be adjusted according to the biomass raw materials, the system operation safety is high, and the cost is low.

Description

technical field [0001] The invention relates to a method for microwave pyrolysis polygeneration of biomass, in particular to a method for combined water washing-baking pretreatment of biomass microwave pyrolysis polygeneration. Background technique [0002] Biomass pyrolysis is one of the important ways to develop and utilize biomass. Pyrolysis can produce three products: biomass semi-coke, syngas and bio-oil. In biomass pyrolysis under traditional heating methods, heat is transferred from the surface of the material to the interior through heat conduction or convection, while microwave heating converts microwave energy into thermal energy in the form of dissipation, which can generate overall uniform heating, and heating The fast rate will lead to some pyrolysis conditions different from traditional pyrolysis, and finally form different pyrolysis characteristics. [0003] Biomass usually has a high content of alkali metals and alkaline earth metals. Direct pyrolysis withou...

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Problems solved by technology

[0003] Biomass usually has a high content of alkali metals and alkaline earth metals. Direct pyrolysis without pretreatment will have many adverse effects. In the process of pyrolysis, alkali metals and alkaline earth metals change the reaction path of biomass pyrolysis and catalyze the secondary cracking of bio-oil, reduce the yield of bio-oil and increase the small molecular components in bio-oil Components such as acids, ketones, aldehydes, etc., make bio-oils less stable and complex in composition; alkali metals and alkaline earth metals promote H during the pyrolysis process. 2 O and CO 2 generation, the calorific value of pyrolysis synthesis gas decreases, which affects its utilization efficiency

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