A computational fluid dynamics (CFD)study intoa hydrodynamic factor that affects abio-hydrogen production process in a stirred tank reactor

Hydrogen production by fermentation is a process that involves a multiphase system, in which the hydrodynamic factor plays a major role in the improvement of efficiency. Analysis of the multiphase system is urgently needed in order to elucidate the flow pattern phenomena that occur within a fermenter. The computational fluid dynamics (CFD) study that is described in this paper was used to simultaneously calculate the gas-liquid system, reaction, multiple components and fluid flow models. This studyprovides comprehensive, detailed information about the flow pattern, hydrogen gas distribution, and rate of hydrogen gas production that evolved from the surface of the liquid media. A 5 l fermenter was modeled as a standard agitated tank equipped with a 6-bladed 45°Pitched Blade Turbine (PBT). The important models used to design and conduct this CFD study were the Eulerian model for a gas-liquid system, the multiple reference frames (MFR) model for impeller movement, and the laminar finite-rate model forreaction. The effect of the impeller rotational speed, as a hydrodynamic factor in hydrogen production based on CFD,was discussed, and the theoretical results qualitatively agreed well with the experimental results.