The effect of temperature and effluent recycle rate on hydrogen production by undefined bacterial granules

• Published in: Bioresource technology 2011-10, Vol.102 (19), p.8986-8991
• Main Authors: Ngoma, L., Masilela, P., Obazu, F., Gray, V.M.
• Format: Article
• Language: English
• Subjects: Anaerobic; Bacteria; Bacteria, Anaerobic - metabolism; Biofuel production; Biofuels; Biohydrogen; Biological and medical sciences; Bioreactors; Biotechnology; Biotechnology - methods; Effluent recycling; Energy; Fluidized bed; Fundamental and applied biological sciences. Psychology; Granules; Hydrogen - metabolism; Industrial applications and implications. Economical aspects; Temperature
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2011.06.083

► Rapid bacterial granulation was induced under thermophilic conditions, 45 and 70°C. ► The 45 and 70°C treatments gave % H2 contents of 45% and 67%, respectively. ► Extreme rates of effluent recycling up to 3.5L/min were applied to the bioreactor. ► At 70°C high effluent recycling and low HRTs resulted in volumetric rates up to 14.8L H2/L/h. Biohydrogen production in an anaerobic fluidized granular bed bioreactor was strongly dependent on temperature and effluent recycle rates. At 45°C as the effluent recycle rate was increased from 1.3 to 3.5L/min, the total H2 output for the bioreactor increased from 10.6 to 43.2L/h. Volumetric H2 productivity also increased from 2.1 to 8.7L H2/L/h. At 70°C as the effluent recycle was increased from 1.3 to 3.5L/min, the total H2 output for the bioreactor increased from 13.8 to 73.8L/h. At 70°C volumetric H2 productivities increased from 2.8 to 14.8L H2/L/h as the effluent recycle rate was increased from 1.3 to 3.5L/min. At 45°C % H2 was 45% and reached 67% at 70°C. Maximum hydrogen yields at 45°C were 1.24 and 2.2mol H2/mol glucose at 70°C.