Fast pyrolysis behaviors of cedar in an infrared-heated fixed-bed reactor

摘要

To explore fast pyrolysis behaviors of cedar biomass, the infrared heating technique with quick heating rate was taken in a fixed-bed reactor. The effects of heating rates (5-30 degrees C/s) and pyrolysis temperatures (400-600 degrees C) on pyrolysis products distribution and compositions were discussed, and the reaction mechanism was proposed. The results show that high heating rate can significantly suppress secondary reaction of primary volatiles. GC/FID and GC/MS analyses indicate that higher heating rate is favorable to the generation of glucose derivatives such as acids and furans. However, higher temperature can obviously promote further conversion of guaiacyl-contained structure following demethylation, demethoxylation and center dot H/center dot CH3 assisted demethoxylation routes, which were proposed to interpret the formation of biphenolic hydroxyl and monophenolic hydroxyl compounds such as phenol, 2-methyl-phenol and 2,4-dimethyl-phenol, respectively. Moreover, the demethylation route exhibits obvious conversion advantage at higher temperature due to lower energy barrier.