High-Resolution Particle-Scale Simulation of Biomass Pyrolysis

Abstract

Pyrolysis is an important process encountered in direct combustion, gasification, and fast pyrolysis of solid biomass materials. This paper describes a computational study of biomass pyrolysis at the particle scale, considering the intraparticle transport phenomena and flow fields surrounding the particles. The lattice Boltzmann method, chosen to solve the conservation equations, was coupled with a chemical reaction mechanism to simulate the pyrolysis kinetics. The flow field was directly resolved at a scale smaller than the particle size, and Darcy’s law was employed to simulate the gas flow in the porous biomass particle. The present numerical method was validated by predicting the pyrolysis process of a single biomass particle. The numerical results agreed with experimental data on the temperature history and extent of conversion of the biomass particle under pyrolysis conditions. A small-scale fast pyrolysis reactor was also simulated. The numerical results indicated that the pyrolysis process may be ...