Integration of mixing, heat transfer, and biochemical reaction kinetics in anaerobic methane fermentation

• Published in: Biotechnology and bioengineering 2012-11, Vol.109 (11), p.2864-2874
• Main Author: Wu, Binxin
• Format: Article
• Language: English
• Subjects: Anaerobiosis; Bacteria - growth & development; Bacteria - metabolism; Biochemistry; biological process; bioreactor; Bioreactors - microbiology; Chemical reactions; computational fluid dynamics; Energy conservation; Energy efficiency; Fermentation; Fluid dynamics; Heat transfer; Hot Temperature; Hydrodynamics; Kinetics; Methane - metabolism; Models, Statistical; physical process; Reaction kinetics
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.24551

An extensive investigation of anaerobic methane fermentation requires identifying the relationship between the physical environment and biological process. In this study, a computational fluid dynamics (CFD) technique was used to characterize bacterial fermentation mechanisms intertwined with mixing and heat transfer in anaerobic digesters. The results demonstrate that the methane yield remains almost unchanged while the energy efficiency decreases with increasing mixing power in a complete‐mix digester, and that the energy output increases nonlinearly with the increase in heating energy in a plug‐flow digester. The CFD method can be applied to other bioreactors to gain valuable insights into their behavior as well. Integrating flow and temperature with kinetic behavior for anaerobic digestion not only solves the controversy about how mixing influences the digestive process, but also assists in optimizing the digester design and increasing the efficiency of energy conversion, and additionally, provides a reference for improving the mixing guidelines recommended by the U.S. Environmental Protection Agency. Biotechnol. Bioeng. 2012; 109: 2864–2874. © 2012 Wiley Periodicals, Inc. A computational fluid dynamics (CFD) simulation platform is developed to characterize physical‐biological interactions in anaerobic methane fermentation. The relations among mixing, heat transfer and biochemical reactions in complete‐mix and plug‐flow digesters are quantitatively identified in order to analyze the energy efficiency. The CFD technique can be applied to the modeling of biohydrogen fermentation and other bioenergy sources.