Modelling of Multi-Stage Internal Loop Air Lift Bioreactor Utilizing Computational Fluid Dynamics

Abstract

In this study, Computational Fluid Dynamics (CFD) is utilized to compare the hydrodynamics of internal loop air lift bioreactors with three different internal configurations. This CFD study compares how splitting the draft tube into multiple stages affects the hydrodynamics of an airlift bioreactor. An in-house Lagrangian particles coupling utility is integrated into an Eulerian solver to evaluate the residence time distribution in each circulation loop. The results showed that the single draft tube geometry maintains a constant downcomer velocity, while the double-stage and triple-stage geometries have higher downcomer velocities on the top section and a more stable downcomer velocity, respectively. Higher recirculation rates can be obtained on the triple-stage reactor configuration. Overall, these findings provide valuable insights for the optimization and design of internal loop air lift bioreactors for various biological applications.