MODELING TAR EVOLUTION DURING BIOMASS PYROLYSIS IN A FLUIDIZED BED REACTOR BY USING A CFD–DEM METHOD

Biomass gasification in fluidized bed reactors is one of the most important utilization methods through thermochemical conversion. Tar generation is the bottleneck of this technology. In this work, numerical simulations for biomass tar evolution under medium to high temperature pyrolysis conditions are carried out by combining a Euler–Lagrangian framework with a multistep pyrolysis model and a new tar cracking model. Comparison for the tar cracking under 600℃~800℃ operation conditions is studied and the corresponding effect on the light gas yield is also analyzed. Numerical results indicate that the established model can reasonably capture the influence of tar cracking on the pyrolysis yields. The current work provides a useful tool for the understanding of biomass pyrolysis in fluidized bed reactors.