Hydrodynamics of Gas-Liquid-Solid Fluidized and Semi-Fluidized Beds

Abstract

Two-phase and three-phase fluidized beds have been applied successfully to many industrial processes such as in the H-oil process for hydrogenation and hydrodesulfurization of residual oil, the H-coal process for coal liquefaction, Fischer-Tropsch process, and the bio-oxidation process for wastewater treatment. A semi-fluidized bed has the advantages of both the packed and the fluidized beds as it can partly over come the disadvantages of a fluidized bed, namely back-mixing of solids, attrition of particles and erosion of surfaces, and those of a packed bed, such as non-uniformity in bed temperatures, segregation of solids and channeling. Semi-fluidized beds have been applied successfully to many industrial processes (physical, chemical and biochemical)such as in the filtration, adsorption, catalytic reactions, heavy metal removal and recovery, coal pyrolysis, bio-oxidation, ethanol fermentation, granule tablet manufacturing etc.