Multiphase Computational Fluid Dynamics (CFD) study of the propagation step of microorganisms in STR bioreactor to obtain high cell density culture.

Author(s)

André Martins Berger Peralta

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola Politécnica (EP/BC)
• Defense date: 2022-08-23

Examining board members

José Luis de Paiva; Efraim Cekinski; Thomaz de Gouveia

• Advisor: José Luis de Paiva

Abstract

A CFD study was carried out to evaluate the fluid dynamics characteristics of a bioreactor stirred by three Rushton impellers. The system was studied under single-phase (liquid phase only), biphasic (liquid and gaseous phase) and three-phase (cell addition) conditions. The objective was to obtain information about the operational conditions of a high cell density culture. Conditions of velocity fields, oxygen transport, vortex formation and mixing quality were observed. The single-phase results were in agreement with the literature, demonstrating the formation of vortices in the lower and upper regions of the bioreactor. The inclusion of the gas phase showed the influence of the upward flow of air, displacing the vortices and reducing their velocities. The analysis of oxygen transport produced results very close to those predicted by the Cooper method, reaching percentage differences between 1.6% and 12%. When inserting the solid phase, correlations were sought in the literature to consider the impact of cells on fluid viscosity. Then, from the comparison with cultivation data, the systems ability to predict the oxygen transport conditions at different times of the process was observed, obtaining percentage differences in relation to the experimental data between 11% and 85%. (AU)

• FAPESP's process: 19/06377-5 - Computational fluid dynamics (CFD) study of a multiphase microorganism propagation step of a high-density bioreactor STR growth
• Grantee: André Martins Berger Peralta
• Support Opportunities: Scholarships in Brazil - Master