生物质快速热解气相成分析出规律

利用恒温沉降炉对秸秆、稻壳、木屑及一种烟煤煤粉在900、1000、1100℃ 3个温度进行了快速热解试验,对4种燃料在快速热解过程中气相成分析出的规律进行了研究.生物质成分中高的挥发分、氧、H/C决定了其快速热解会取得比煤粉高的气相产率,木屑的气相产物产量最多,秸秆次之,稻壳最低.4种燃料热解气相产物中的主要成分是CO、H_2、CO_2、CH_4,少量的G_2H_4、C_2H_6、NO、HCN、COS,生物质和煤粉在快速热解及短的停留时间内,其析出的氮前驱物为HCN.快速热解析出的气相成分产量及组分分布与燃料种类、热解温度、热解停留时间相关.几种物料共同的规律是随停留时间的延长,气相产物的量不断地增加,当气相产物的产量趋于平稳时,相应的气相产物的各组分趋于恒定,这一停留时间标志着热解过程的结束,相同温度条件下煤粉的热解速率要慢于3种生物质.

STUDY ON RELEASE BEHAVIOR OF GAS COMPONENTS OF BIOMASS IN FAST PYROLYSIS

The release behavior of gas components of straw、rice husk、sawdust and bituminous coal was investigated in a drop tube deposition furnace at fast pyrolysis temperature of 900、1000、1100℃ . The volatile, oxygen and H/C of biomass components was higher than that of bituminous coal, which determins a higher gas yield in the fast pyrolysis. The gas yield of sawdust is the greatest, that of straw is the second and that of rice husk is minimum. The main components of pyrolysis gas is CO, H_2, CO_2 and CH_4, while other components, such as C_2H_4、NO、HCN、COS are relatively less. HCN is the nitrogen precursors in short residence time for fast pyrolysis. The gas yield and compsition in the fast pyrolysis are related to the fuel types, pyrolysis temperature and residence time. The common law for several fuel are as follows: when the residence time increased and the gas yield stabilized, the corresponding components of gas product tend to be constant. This time can be considered as the end of pyrolysis process. The pyrolysis rate of pulverized coal is slower than that of biomass at same temperatures.