(546c) Multiphase Simulation of Bioreactors to Improve Biofuel Production at Scale

There is an increasing demand for commercial aviation fuels with low carbon footprint, such as sustainable aviation fuels (SAF), due to the global air transport industry’s commitment to carbon-neutral growth and net-zero carbon emissions by 2050 [1]. The main challenge is to increase the production of SAF to meet increasing world-wide demand at costs that are comparable to those of existing fossil fuels. At small scales in a laboratory setting, gas fermentation bioreactors have been demonstrated to generate exceptionally high product yield. However, when scaled up for mass industrial production, these systems exhibit significant performance reductions. In this work, we use computational models to elucidate the key factors affecting the efficiency of bioreactors at industrial scale.

A Michaelis–Menten kinetic model for the growth and uptake rates of the relevant microorganisms, substrate and other dissolved species, is developed using data from lab-scale stirred tank bioreactors. This model is coupled with a multiphase fluid dynamics model [2,3] and validated using data from the lab-scale bioreactor, then used to estimate the performance of an industrial-scale stirred tank bioreactor. Detailed analysis of the hydrodynamics as well as the substrate concentrations inside this bioreactor enables us to identify the key factors that impact production efficiencies at industrial scale.

References:

[1] https://www.iata.org/en/programs/environment/sustainable-aviation-fuels/

[2] Rahimi, M. J., Sitaraman, H., Humbird, D., and Stickel, J. J. (2018). Computational fluid dynamics study of full-scale aerobic bioreactors: Evaluation of gas–liquid mass transfer, oxygen uptake, and dynamic oxygen distribution. Chemical Engineering Research and Design, 139, 283–295

[3] Sitaraman H, Lischeske J, Stickel J & Lu Y (2023). A reacting multiphase computational flow model for 2,3-butanediol synthesis in industrial-scale bioreactors, Chemical Engineering Research and Design, 197, 2023, 38-52