Modeling of Coal-Biomass Fluidization Using Computational Fluid Dynamics

In an effort to assess the fluidization characteristics of coal-biomass mixtures, computational fluid dynamics (CFD) was used and validated. The gas and solids phases were modeled using an Eulerian-Eulerian approach to efficiently simulate the physics. The computational platform Multiphase Flow with Interphase eXchanges (MFIX) was employed to simulate the particle-particle interactions of coal-biomass mixtures and compare the predictions with experimental data. The coal-biomass mixtures included sub-bituminous coal and hybrid poplar wood. Particles properties of both materials fall within the Geldart A classification. Of particular interest to this study was predicting particle mixing in fluidized beds and biomass hydrodynamics. Both materials and two mass ratio mixtures were studied and pressure drop across the bed for various gas inlet velocities and bed height were analyzed and compared to the experiments.