(480e) Advances in Gas Sparging Simulation for Bioreactor Modeling to Create Comprehensive “Simulation Design Space”

Gas-liquid dispersion in stirred tanks
is a commonly used industrial process, e.g., bio-pharmaceutical or
fine-chemical manufacturing. While CFD models have been used to predict gas
holdup, bubble size distribution and mass transfer coefficients, there have
been fewer studies on deploying the CFD models to range of operating
conditions. This study focuses CFD simulation at different rotational speed
(rpm) and gas flow rates to create a comprehensive ?Simulation Design Space? for
mass transfer co-efficient (Kla). Mass transfer
co-efficient is experimentally obtained by measuring Dissolved Oxygen (DO)
concentration by absorption in pure water.  In current study, simulation model is
developed numerically to calculate DO through multiphase and multispecies CFD
simulations. Population balance model is coupled with the Eulerian multiphase-multispecies
model to predict the bubble size distribution and oxygen distribution. The
study also looks into effects of turbulence on drag co-efficient which is a key
factor in predicting an accurate bubble size distribution and gas hold-up.
Simulation best practices are developed and then deployed for validation of the
model against experimental data [1] on wide range of operating conditions.

1. M. Laakkonen et al., Chemical
Engineering Science 62 (2007) 721 ? 740