Numerical Study of Fast Pyrolysis of Woody Biomass in a Gravity-Driven Reactor

摘要

In the present study, computational fluid dynamics is applied to investigate fast pyrolysis characteristics of woody biomass in a gravity-driven reactor. A Eulerian-Eulerian approach is adopted, including three gas species and three solid phases, for multiphase reacting flow fields between solid and gas. Two-stage semiglobal reaction kinetics considering the secondary tar cracking mechanism is used for simulation of the pyrolysis reaction. The flow and pyrolysis reaction characteristics of the reactor are investigated, and the reaction rates of woody biomass pyrolysis are evaluated for streamwise locations in the reactor. Also, the inlet condition and inclination angle are changed to study their effects on the reaction. From the predicted results, it is seen that the heat transfer to biomass is governed mainly by mixing of particles, and this influences the final pyrolysis reaction.