Hydrodynamic characterization of materials for gas treatment by biofluidization

The fluidization of possible microorganism supports has been studied. The fluidization of scrap-wood particles and of polyurethane foam cylinders was characterized by measuring their minimum fluidization velocities and compared with predictions from the literature. Minimum fluidization velocity increases with the water content of the scrap-wood more than predicted by change in size and density, thus probably involving interparticle forces at high moisture levels. Two types of polyurethane foam cylinders have been also characterized from fixed bed to entrainment regimes. Measurement of the pressure drop in the fixed bed state and of the minimum fluidization velocity suggest that flow occurs through these porous particles, as well as around them. Nevertheless the contribution of the internal particle porosity to the flow decreases from the fixed bed to the entrained regime. The onset of entrainment is well predicted by correlations established for non-porous materials.