Mixing and solid-liquid mass transfer characteristics in a three phase pulsed plate column with packed bed of solids in interplate spaces-a novel aerobic immobilized cell bioreactor

Abstract

Background: The pulsed plate column (PPC) with packed bed of solids in the interplate spaces finds use as a three phase aerobic bioreactor and is a potential heterogeneous catalytic reactor. Good knowledge of the extent of mixing in the liquid phase and solid-liquid mass transfer coefficient are essential for modeling, design and optimization of these columns. The present work aims at the study of liquid phase mixing and solid-liquid mass transfer characteristics in a three phase PPC. Results: Residence time distribution studies were performed. Dispersion number was found to increase with increase in liquid superficial velocities, frequency of pulsation, amplitude of pulsation and the vibrational velocities. Increase in frequency and amplitude of pulsation, and hence increase in vibrational velocity, resulted in increase of the solid-liquid mass transfer coefficient. Conclusions: The mixing behaviour in this contactor approximated a mixed flow behaviour. The three phase PPC was found to outperform many other kinds of three phase contactors in terms of solid liquid mass transfer characteristics. Empirical correlations developed can be used for the determination of solid-liquid mass transfer coefficients for three phase PPC and hence can facilitate the design, scale-up and modeling of these columns, when used as chemical or biochemical reactors. © 2011 Society of Chemical Industry.