Hydrodynamic and oxygen mass transfer in an external loop airlift bioreactor with a packed bed

A dynamic, spatial model was used to predict the transient, oxygen concentration distribution in the ELAB with and without a packed bed. This model was compared to simulating the ELAB as a completely stirred reactor and demonstrated improved prediction of the cyclical changes in liquid oxygen concentrations. The oxygen mass transfer coefficient was determined as a best fitting parameter of the model and at higher gas superficial velocities was found to increase to values approaching 0.021 s−1 using the small amount of packing. Finally, simplified correlations were developed to predict the oxygen mass transfer coefficient in the ELAB with and without the packed bed.