Photobioreactor Design for Hydrogen Production

The goal of the present study consist of understanding the hydrodynamic of air-water multi-phase flow inside a bubble column. Experiments in a 0.04m diameter, 0.86m height were carried out to determine: gas holdup, bubble diameter, axial dispersion. In such case the effect of superficial gas velocity was studied. The gas holdup was obtained by liquid height measurements. Residence time distribution experiments were carried out by determining the tracer evolution. The used tracer was potassium chloride which was injected as impulsion to characterize the mixing of the liquid phase in batch mode. It was found that the gas holdup, increased with increasing superficial gas velocity. Empirical correlations have been proposed to predict air-water system in the bubble column. The diameter of the bubbles formed using porous spargers varies from 2.5 mm to 8.5 mm. The flow behaviour inside the bubble column was modeled by the dispersed plug flow model, the results are in agreement with the model. The results of this work provided a tool to design bubble column reactors in applications such as fermentation, especially to hydrogen production from microalgae. In the latter case experiments are carried out under sulfur-deprived-medium.