Particle-scale simulation of air-blown gasification of biomass materials in bubbling fluidized bed reactor

Biomass gasification is a potential way for yielding product gases and energy, featuring by complex multi-physics and multi-phase flow. The multiphase particle-in-cell approach is adopted in the current study to investigate the behaviors of char, sand and biomass during biomass gasification in an air-blown bubbling fluidized bed. In the multiphase particle-in-cell method, particles are assumed adiabatic inside the body, and particles with identical properties are lumped into a parcel to reduce computational cost. The numerical model was well validated with experimental data. Some key conclusions can be drawn as: syngas has very similar but asymmetrical spatial distribution in the reactor due to the radially introduced raw biomass. Near the biomass inlet, biomass materials have large Reynolds number and heat transfer coefficient. Along the bed height, sand particles have largest heat transfer coefficient, followed by char and finally biomass. Enlarging bed temperature slightly increases the rising flux of biomass particles. This work emphasizes the significance of particle characteristics during biomass air gasification, and may supply useful guidance for industrial development and reactor design.