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

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 3.5 L/min, the total H2 output for the bioreactor increased from 10.6 to 43.2 L/h. Volumetric H2 productivity also increased from 2.1 to 8.7 L H2/L/h. At 70 °C as the effluent recycle was increased from 1.3 to 3.5 L/min, the total H2 output for the bioreactor increased from 13.8 to 73.8 L/h. At 70 °C volumetric H2 productivities increased from 2.8 to 14.8 L H2/L/h as the effluent recycle rate was increased from 1.3 to 3.5 L/min. At 45 °C % H2 was 45% and reached 67% at 70 °C. Maximum hydrogen yields at 45 °C were 1.24 and 2.2 mol H2/mol glucose at 70 °C.