Performance of Biological hydrogen Production Process from Synthesis Gas, Mass Transfer in Batch and Continuous Bioreactors

Biological hydrogen production by anaerobic bacterium, Rhodospirillum rubrum was studied in batch and continuous bioreactors using synthesis gas (CO) as substrate. The systems were operated at ambient temperature and pressure. Correlations available in the literature were used to estimate the gas-liquid mass transfer coefficients (KLa) in batch reactor. Based on experimental results for the continuous reactor, new correlation was generated. The results showed that the agitation, gas flow rate and dilution rate were greatly influenced the hydrogen production as well as on KLa. It was found that the KLa of continuous bioreactor was 180 times higher than the mass transfer coefficient reported in batch reactor. It can be considered that the estimation of KLa for the continuous bioreactor may be successful for the large-scale biological hydrogen production.