Biohydrogen production through photo fermentation or dark fermentation using waste as a substrate: Overview, economics, and future prospects of hydrogen usage

Hydrogen has been introduced as a potential replacement for energy resource due to the depletion of fossil fuel and raising awareness about global climate change and health problems caused by the combustion of fossil fuel. One of the attractive options to produce hydrogen is through microbial fermentation which can be classified into biophotolysis, dark fermentation, photofermentation, and microbial electrolysis cell. Among these, dark fermentation and photofermentation technologies were processes that were being studied widely. One of the reasons is that organic waste could be reused as a substrate during biohydrogen production. Although the current biohydrogen yields are low, it is expected that with improvements technology and genetic engineering, the amount of generated biohydrogen could be enhanced tremendously, and provide a sustainable way of reutilizing waste as a substrate. Thus, this paper reviews the principles of photofermentation and dark fermentation by reusing various wastes as substrates. The resulting performances, limitations, as well as future prospects of hydrogen usage and hydrogen economy are also discussed. (c) 2013 Society of Chemical Industry and John Wiley & Sons, Ltd