Influence of Biomass Pyrolysis Temperature, Heating Rate and Type of Biomass on Produced Char in a Fluidized Bed Reactor

Biomass pyrolysis experiments were carried out in a fluidized bed reactor (FBR) and produced char yields were measured for 3 kinds of softwoods, 3 kinds of hardwoods, 2 kinds of herbaceous plants and 3 kinds of agricultural residues. Pyrolysis temperature range was between 300 °C and 1200 °C, and heating rate was fast (100–1000 °C/s) or slow (10 °C/min). After the pyrolysis, produced char was collected with bed particles and only the char was separated from bed particles by sieving. Surface of the produced char was observed by SEM to confirm bed particles adhesion behavior on the surface of char. Char-bed particles (alumina particles) adhesion were observed mainly under fast pyrolysis condition for most of the biomass samples. Char yields by fast pyrolysis were much lower than those by slow pyrolysis of Eucalyptus camaldulensis (hardwood), Japanese cypress (softwood), Switchgrass (herbaceous plant) and Bagasse (agricultural residue), respectively. In the case of fast pyrolysis condition, char yields from softwood species were lower than those from other biomass species.