Study On Pyrolysis Mechanism And Reaction Kinetics Of Biomass

The exploitation and utilization of biomass energy will relieve the pressure caused by fossilfuel shortage and environmental pollution, which has vital significance to establish sustainabledevelopment stratagem in China. Biomass pyrolysis technology is one of the effective methodsof biomass energy conversion and utilization.Firstly, by a summarization of the domestic and foreign biomass pyrolysis, the biomassCurie-point pyrolysis is decided as an important part of this thesis, and it combines withordinary pyrolysis and reaction kinetics to investigate on the pyrolysis characteristic ofbiomass comprehensively.Experiments on pyrolysis process and kinetics of poplar sawdust are done on an automaticthermogravimetic analysis at various heating rates, and the optimal kinetics reaction order of 1is obtained by comparison of different reaction orders, then the activation energy andfrequency factor are solved.Many experiments of several kinds of typical materials are done in ordinary pyrolysis toinvestigate on the effects of pyrolysis temperature and vapor to the yields of liquid and solidproducts. The results show that the yield of liquid products are low at the heating rate about30℃/min of this experimental condition. As the pyrolysis temperature increasing the yield ofliquid products climb up then decline, but for solid is always declining, and the yield of liquidproducts reach maximum at temperature between 550℃to 600℃. The vapor has effect on theyields of liquid and solid products, but that is not the dominant factor.The Curie-point pyrolyzer that directly connected with gas chromatography and massspectrometry is to on-line analyze the pyrolysis liquid products, and the effects of various rawmaterials and Curie-points with main pyrolysis liquid products are also discussed. The researchshows that the composition of biomass Curie-point pyrolysis liquid products are verycomplicated, which are made up of furfural and aromatic substances, and the relative content ofmain liquid products climb up then decline as the pyrolysis temperature increasing at thisexperimental condition, and the temperature between 445℃to 590℃is fit for pyrolysisliquid products.This study is advantageous to the mechanism research on biomass pyrolysis. Finally, the upgrading and prospect of bio-oil are also introduced in this thesis.