2018 Volume 97 Issue 5 Pages 97-104
During the fluidized bed fast pyrolysis/ gasification of woody biomass, a few characteristic phenomena were observed. In our small scale fluidized bed fast pyrolysis, agglomerates were found in the bed, which will cause serious engineering problems, such as plugging and defluidization. In the present study, the agglomerates formed were recovered and weighed after pyrolysis of Japanese cypress with different particle diameters using two bed materials of porous alumina and silica sand. The agglomeration was found to be observed mainly between 500-900 °C. Then soluble organic compounds were extracted and the agglomerates were again weighed. The reduction in weight of agglomerates was correlated with the weight of recovered organic compounds. In all of the results, some effects of bed particle and biomass particle diameter were observed. Then the in-situ gasification of biomass char produced was conducted at between 800-1100 °C for different bed materials. The progress of the gasification was different between two bed materials. The different behavior observed in pyrolysis and gasification was explained by the difference in volatile release behavior between large and small biomass particles and by the difference in adsorption/decomposition behavior of volatile between two bed materials.
