Oxygen Mass Transfer Coefficients in a Three-Phase Pulsed Plate Bioreactor

Volumetric oxygen mass transfer coefficient is a decisive parameter for the selection of any contactor as an aerobic bioreactor. A pulsed plate column with fixed bed of solids in interplate spaces is a recent innovation in the field of immobilized cell bioreactors. Volumetric oxygen mass transfer coefficients are determined in a three-phase pulsed plate column involving air and water phases and with a fixed bed of glass particles, which can serve as a surface for cell immobilization packed in the interplate spaces. The volumetric mass transfer coefficients obtained in this column range from 0.067 to 0.1495 s(-1) in the range of air superficial velocities from 0.011 to 0.047m/s and vibrational velocities from 0.825 to 6cm/s. Volumetric oxygen mass transfer coefficient has increased with the increase in superficial air velocity and vibrational velocity. Empirical correlation relating k(L)a with these variables was developed. The volumetric oxygen mass transfer coefficient values in the three-phase pulsed plate column are found to be similar or higher than the literature reported values for conventional two-phase pulsed plate columns. The values of volumetric oxygen mass transfer coefficients in the three-phase pulsed plate column are of higher order of magnitude than the literature reported values of volumetric oxygen mass transfer coefficient for many other three- phase gas-liquid-solid reactors. The pulsed plate column with fixed bed of solids is proven to have all the potential to be used as an aerobic bioreactor with immobilized cells due to its better gas-liquid mass transfer characteristics.