Photofermentative biohydrogen generation from organic acids by Rhodobacter sphaeroides O.U.001: Computational fluid dynamics modeling of hydrodynamics and temperature.

Hydrogen gas is a clean-burning fuel suitable for powering public vehicles. Hydrogen fuel has the highest energy density (143 MJ kg-1 ). This research paper emphasizes three-dimensional hydrodynamics and temperature distribution during photobiohydrogen generation by Rhodobacter sphaeroides strain O.U.001 in a triple-jacketed 1 L photobioreactor (PBR). The fermentation broth has turbulent flow conditions and light gradients among various layers, which affect the light conversion efficiency of the PBR. From the carbon source (malic acid), various organic acids are produced within fermentation (lactate, acetate, and formate). Modeling and simulation studies by computational fluid dynamics confirmed uniform fluid dynamics and heat transfer throughout the annular PBR. The modified Gompertz equation gave good simulated fitting with an experimental value for H2 generation. R. sphaeroides O.U. 001 gave good simulated results for H2 generation with mathematical modeling of substrate consumption kinetics and substrate utilization for biomass.