In a feasibility study of 15 months funded Engineering and Physical Sciences Research Council (EPSRC) up to 24 000 pounds (about 35 000 euros), researchers from the School of Biosciences, University of Birmingham have shown that a specific bacterium produces hydrogen when it feeds on highly sugary waste. The tests were performed with waste from the international confectionery and beverage company Cadbury Schweppes, which is based in Birmingham. Another partner, C-Tech Innovation, studied the economics of the process and showed that this technology could be interesting on a larger scale.
In tests carried out in a demonstration reactor 5 liters, these bacteria were added to a mixture of diluted nougat and waste from the manufacture of caramel.
The bacteria were then consumed sugar, producing hydrogen and organic acids. Another type of bacteria is introduced into a second reactor in order in turn to convert organic acids into hydrogen. Hydrogen is fed thereafter a fuel cell to generate electricity (chemical reaction between hydrogen and oxygen from the air). The carbon dioxide formed in the first reactor is captured and sequestered not be released into the atmosphere.
The resulting process biomass waste are removed, mixed with palladium and then used as catalysts in another research project. This second project is funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and aims to identify different mechanisms for removing pollutants such as chromium and polychlorinated biphenyls (PCBs). The catalytic reactors used in this parallel project also require hydrogen that is supplied by the confectionery waste.
This process is clean, saves energy and allows confectionery industries recover their waste rather than depositing them in landfills as they currently do. This process could theoretically be used by most food processing companies.
However, tests with potato extracts were inconclusive.
Professor Lynne Macaskie of the University of Birmingham believes the system could be developed for industrial electricity production and waste treatment processes. The research team is currently engaged in a follow-up work to obtain more information on the overall potential of this technique with "sweet" waste more varied.