HYDRODYNAMIC AND MASS-TRANSFER STUDY OF A GAS-LIQUID-SOLID DRAFT TUBE SPOUTED BED BIOREACTOR

It has already been proved that the soft polyurethane foam particles are very effective carriers for immobilizing fungi and/or mycelia. However, the classic three phase fluidized bed bioreactor was not effective enough for the production of antibiotics like penicillin due to the lower value of the mass transfer rate of oxygen. In order to improve this parameter, we introduced a draft tube in the reactor thus obtaining a gas-liquid-solid draft tube spouted bed bioreactor. The effect of both design and operational parameters on the mass transfer rate of oxygen was studied experimentally. It was shown that the volumetric mass transfer rate of oxygen in the new bioreactor was increased between 1.5 and 3 times as compared to a conventional three phase fluidized bed. Indications for scaling-up of the bioreactor for industrial use were also obtained.