Bacteria munching through confectionery give off hydrogen gas as they consume high-sugar waste produced by the confectionery industry and the hydrogen could be used to generate clean electricity via a fuel cell, scientists have demonstrated.

In a feasibility study, biologists at the University of Birmingham, England, introduced diluted nougat and caramel waste into a 5-liter demonstration reactor and added the bacteria, which the researchers identified as potentially having the right sugar-consuming and hydrogen-generating properties.

As a result, the bacteria consumed the sugar, producing hydrogen and organic acids, according to a press release by the university on Tuesday.

The scientists introduced a second type of bacteria into a second reactor to convert the organic acids into more hydrogen, and the hydrogen produced was fed to a fuel cell, in which it was allowed to react with oxygen in the air to generate electricity.

Carbon dioxide produced in the first reactor was captured and disposed of safely, preventing its release into the atmosphere. The 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.

The reactors used by this parallel initiative also required hydrogen supplied by the confectionery waste initiative too, further underlining the "green" benefits offered by the new hydrogen production technique.

Professor Lynne Macaskie, who led the research team, was quoted as saying: "Hydrogen offers huge potential as a carbon-free energy carrier and 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."

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, much of which is currently disposed of in landfill sites.

The team is now engaged in follow-up work to produce a clearer picture of the overall potential for turning a wider range of high-sugar wastes into clean energy using the same basic technique.

Source: Xinhua