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采用管式反应器与傅里叶变换红外分析(Fourier transform infrared,FTIR)联用技术进行了生物质热解特性及主要气体产物释放规律的研究。结果表明,农业生物质热解的主要气体产物有H2O、CO2、CO、CH4、C2H6、C2H4、HCOOH、CH3OH和酚类化合物等。热解过程中先析出游离水,随后发生解聚和脱水反应,主要的C-C键、糖苷键、羰基、羧基、甲氧基和C-O-(C)等基团发生断裂和重整反应,生成CO,CO2、CH4和醇、酸、醛、酚类等物质;在炭化阶段,C-H键和C-O键进一步断裂和芳香化转化,析出CH4、CO2和CO等。在稻草和玉米秆热解过程中,H2O、CO2、CO和CH4有多个析出极值出现,并分别在309和335℃达到最大析出峰值。CO和CO2的释放主要集中在220～400℃,而CH4的释放主要在较高温度段275～400℃,比CO和CO2的析出温度高出55℃左右。在220～400℃,CO和H2O的释放特性相似。气体产物的释放规律揭示了有关生物质不同组分热行为的重要信息。
The characteristics of pyrolysis of biomass and the release of major gas products were studied by the combination of tube reactor and Fourier transform infrared (FTIR). The results show that the main gas products of agricultural biomass pyrolysis are H2O, CO2, CO, CH4, C2H6, C2H4, HCOOH, CH3OH and phenolic compounds. Precipitation of free water in the pyrolysis process, followed by depolymerization and dehydration reaction, the main CC bond, glycosidic bond, carbonyl, carboxyl, methoxy and CO- (C) and other groups rupture and reforming reaction, the formation of CO , CO2, CH4 and alcohols, acids, aldehydes, phenols and other substances. In the carbonization stage, the CH bonds and CO bonds are further broken and aromatized, and CH4, CO2 and CO are precipitated. In the pyrolysis of rice straw and corn stover, there are several precipitation extremes of H2O, CO2, CO and CH4, and reach the maximum precipitation peak at 309 and 335 ℃ respectively. The release of CO and CO2 mainly concentrated in the range of 220-400 ℃, while the release of CH4 was mainly in the higher temperature range of 275-400 ℃, which was 55 ℃ higher than that of CO and CO2. At 220-400 ℃, the release characteristics of CO and H2O are similar. The release of gaseous products reveals important information about the thermal behavior of different components of biomass.