Overall volumetric mass transfer coefficient in a modified reversed flow jet loop bioreactor with low density particles

Experiments were conducted using glass beads and low-density particles such as polyurethane and polystyrene which are comparable to bioparticles found in biological applications to evaluate the overall volumetric mass transfer coefficient (KLa) in a modified reversed flow jet loop bioreactor having the liquid outlet at the top section of the reactor. The influence of the gas and liquid flow rates, draft tube to reactor diameter ratio, solids loading and physical properties of solids on KLa were studied. The KLa was found to increase with the increased gas and liquid flow rates. The KLa values were found to be higher in the bubbly flow region i.e., at the lower range of energy dissipation rates. The optimum draft tube to reactor diameter ratio and solids loading with respect to maximum KLa were found to be 0.4 and 0.9×10-3 m3 (e{open}s=0.025) respectively. Dimensionless correlations were presented to predict the experimental values in terms of operational and geometrical variables. © 1995 Springer-Verlag.