The CFD Simulation Of Gas-Liquid Bioreactor

With more and more in-depth life science research, design and optimization of bioreactor is also facing greater challenges. Scaling-up is the realization to the level of industrialization as the same environment as laboratory to ensure consistent product. When a reactor is scaled up, many process influencing parameters like KLa, mixing time, power consumption etc. cannot be kept constant at the same time. There is a new method for industrial bioprocess optimization and scale-up by Computational Fluid Dynamics (CFD).In the present paper, based on the combination of Computational Fluid Dynamics (CFD) simulation and experimental results, the simulation method for two-phase gas-liquid bioreactor was obtained and applied for the optimization and amplification of several bioreactors in which the flow field situation in different optimization schemes was obtained to provide support for the design, optimization and amplification of bioreactors. When applied for the design and optimization of a200L fermenter used for S-adenosylmethionine (SAM) production, fermentation experiments were conducted to verify the CFD simulation illustrating the effectiveness of the simulation optimization process. Then the fermentation tank was further amplified to5T using the axial flow blade and runoff oar combinations which made the system dissolved oxygen and liquid circulation conditions ideal to meet the requirements of SAM fermentation. In citric acid fermentation system, the original two-layer runoff oar of the500L fermenter was changed to the axial flow blade and runoff oar combinations which could enhance the materials mixing cycle between the upper and lower body and save the stirring energy consumption for about30%compared to existing programs. Moreover, the above simulation results can provide guidance for the300m3fermenter optimization. In300m3citric acid production fermenter, the usage of the double helical turbine impeller was feasible because of the great reduction of energy consumption. For the Rhodotorula microbial oil production system, the airlift bioreactor was designed based on the dissolved oxygen and flow field circulating demand. In the related fermentation experiments, the biomass could be up to28g/L which met the needs of the fermentation process.