Feasibility of biohydrogen production at low temperatures in unbuffered reactors

• Published in: International journal of hydrogen energy Vol. 34; no. 3; pp. 1233 - 1243
• Main Authors: Gadhamshetty, Venkataramana, Johnson, David C., Nirmalakhandan, Nagamany, Smith, Geoff B., Deng, Shuguang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2009; Elsevier
• Subjects: Alternative fuels. Production and utilization; Anaerobic fermentation; Applied sciences; Bioenergy; Biohydrogen; Energy; Equivalence; Exact sciences and technology; Feasibility; Fermentation; Fuels; Gibbs free energy; Heat treatment; Hydrogen; Hydrogen production; Intermittent pressure release; Partial pressure; Reactors; Sucrose; Temperature; Unbuffered; Temperature; Gibbs free energy; Biohydrogen; Anaerobic fermentation; Unbuffered; Bioenergy; Intermittent pressure release; Biotechnology; Sucrose; Feasibility studies; Feasibility; Hydrogen production; Low temperature
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2008.10.037

Feasibility of biohydrogen production by dark fermentation at two temperatures (22 °C and 37 °C) in unbuffered batch reactors was evaluated using heat-treated compost as inocula and sucrose as substrate, without any initial pH adjustment or inorganic nutrient supplements. Gas production was quantified by two different pressure release methods – intermittent pressure release (IPR) and continuous pressure release (CPR). Hydrogen production (47.2 mL/g COD/L) and sucrose-to-hydrogen conversion efficiency (53%) were both found to be highest at the lower temperature and IPR conditions. Hydrogen production was higher at the lower temperature irrespective of the pressure release condition. The high yield of 4.3 mol of hydrogen/mole of sucrose obtained in this study under IPR conditions at 22 °C is equivalent to or better than the literature values reported for buffered reactors. Even though literature reports have implied potential inhibition of hydrogen production at high hydrogen partial pressures resulting from IPR conditions, our results did not show any negative effects at hydrogen partial pressures exceeding 5.0 × 10 4 Pa. While our findings are contrary to literature reports, they make a strong case for cost-effective hydrogen production by dark fermentation.