Numerical and experimental estimation of global gas holdup in a bubble column bioreactor using computational fluid dynamics (CFD)

Pneumatic bioreactors can provide adequate heat and mass transfer, rapid mixing and good suspension of solids. In this work, the global gas holdup (αG) from a bubble column bioreactor was analyzed experimentally and numerically using CFD. Eulerian model of two fluids was applied for the gas-liquid multiphase simulations. Different specific air flow rates (1.0 to 5.0 vvm) where simulated in order to evaluate the inclusion of lift interfacial forces in the modelling and thee effect of air flow rate in this analysis. The simulations considering lift force effect showed results closer to the experimental data, with the highest values of αG found for the higher specific air flow rate (5 vvm) and the minor bubble diameter (4 mm) analyzed in this study.