Continuous high-temperature fluidized bed pyrolysis of coal in complex atmospheres: Product distribution and pyrolysis gas

摘要

This study is devoted to investigating the continuous coal pyrolysis in a laboratory fluidized bed reactor that fed coal and discharged char continuously at temperatures of 750-980℃ and in N2-base atmospheres containing O_2, H_2, CO, CH_4 and CO_2 at varied contents. The results showed that the designed continuous pyrolysis test provided a clear understanding of the coal pyrolysis behavior in various complex atmospheres free of and with O_2. The effect of adding H_2, CO, CH_4 or CO_2 into the atmosphere on the tar yield was related to the O_2 content in the atmosphere. Without O_2 in the atmosphere, adding H_2 and CO_2 decreased the pyrolysis tar yield, but the tar yield was conversely higher with raising the CO and CH_4 contents in the atmosphere. In O_2-containing atmospheres, the influence from varying the atmospheric gas composition on the product distribution and pyrolysis gas composition was closely related to the oxidation or gasification reactions occurring to char, tar and the tested gas.