24 May 2006
Candy-Munching Bacteria Prodigious Hydrogen Producers
by Kate Melville
Bioscientists at the University of Birmingham in the United Kingdom have demonstrated a reactor that uses hydrogen-producing bacteria and sugar waste to generate electricity via a fuel cell. The researchers involved say the technology could also be used to power hydrogen-fuelled vehicles.
Interestingly, the project used waste products, in this case diluted nougat and caramel waste, from the confectionery industry as "food" for the bacteria. The bacteria had previously been identified by the researchers as potentially having the right sugar-consuming, hydrogen-generating properties. Once in the reactor, the bacteria consumed the sugar, producing hydrogen and organic acids; a second type of bacteria was then introduced into a second reactor to convert the organic acids into more hydrogen. The hydrogen was then fed to a fuel cell, in which it reacted with oxygen in the air to generate electricity.
To keep the whole process "green", waste biomass left behind by the process was removed, coated with palladium and used as a catalyst in another project aimed at identifying ways of removing pollutants such as chromium and polychlorinated biphenyls (PCBs) from the environment.
As well as energy and environmental benefits, the technique could provide the confectionery industry (and potentially other foodstuff manufacturers) with a useful outlet for waste generated by their manufacturing processes.
Much of this waste is currently disposed of in landfill sites. "Hydrogen offers huge potential as a carbon-free energy carrier," said lead researcher Lynne Macaskie, of the University of Birmingham's School of Biosciences. "Although only at its initial stages, we've demonstrated a hydrogen-producing, waste-reducing technology that, for example, might be scaled-up in 5-10 years' time for industrial electricity generation and waste treatment processes."
Check out a video of the reactor.
Source: Engineering and Physical Sciences Research Council