Effect of temperature on particle behavior and heat transfer during fast pyrolysis of biomass in a fluidized bed reactor

The purpose of this study is to investigate the behavior of biomass particles and the characteristic of heat transfer during rapid pyrolysis in a fluidized bed reactor. A multifluid model (MFM) framework integrated with the heterogeneous stiff reaction was used to perform a two-dimensional fluidized bed pyrolysis simulation. The pyrolysis process was modelled using a simplified comprehensive kinetic framework enhanced with homogeneous and secondary reactions. 600 µm-sized particles of biomass were introduced into the reactor at 27 °C, and 400–800 °C was the temperature at which the pyrolysis was carried out. The simulation resulted that the velocities of gas phase and biomass particles were influenced by the temperature and did not for sand particles. The heat transfer dominantly occurred from the gas phase to the sand particles and followed by the gas phase to the biomass particle. However, the sand-to-biomass heat transfer only occurred in the dense region of the fluidized bed reactor; thus, the average heat transfer coefficient was the lowest. The heat emitted from the reactor wall was mainly absorbed by the sand particles and moderately by the gas phase.