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.
Check out a video of the reactor.