Biohidr

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International Journal of Hydrogen Energy 29 (2004) 173 – 185

www.elsevier.com/locate/ijhydene

Biohydrogen production: prospects and limitations to practical application David B. Levina; b ; ∗ , Lawrence Pittb , Murray Loveb a Department

b Institute

of Biology, University of Victoria, Victoria, BC, Canada V8W 3P6 for Integrated Energy Systems, University of Victoria, Victoria, BC, Canada V8W 3P6
Accepted 24 March 2003

Abstract
Hydrogen may be produced by a number of processes, including electrolysis of water, thermocatalytic reformation of hydrogen-rich organic compounds, and biological processes. Currently, hydrogen is produced, almost exclusively, by electrolysis of water or by steam reformation of methane. Biological production of hydrogen (Biohydrogen) technologies provide a wide range of approaches to generate hydrogen, including direct biophotolysis, indirect biophotolysis, photo-fermentations, and dark-fermentation. The practical application of these technologies to every day energy problems, however, is unclear. In this paper, hydrogen production rates of various biohydrogen systems are compared by ÿrst standardizing the units of hydrogen production and then by calculating the size of biohydrogen systems that would be required to power proton exchange membrane (PEM) fuel cells of various sizes.
? 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
Keywords: Biological hydrogen production; Dark-fermentation; Fuel cells

1. Introduction
Energy is vital to global prosperity, yet dependence on fossil fuels as our primary energy source contributes to global climate change, environmental degradation, and health problems [1]. Hydrogen (H2 ) o ers tremendous potential as a clean, renewable energy currency. Hydrogen has the highest gravimetric energy density of any known fuel and is compatible with electrochemical and combustion processes