Biofuel waste product recycled for electricity

A waste product from the manufacture of biofuels has been developed to power fuel cells, which in turn can be used to generate low cost electricity.

The by-product from the manufacture of biofuels is called Distillers Dried Grain with Solubles (DDGS). It is produced from bioethanol production and its main use is as high protein livestock food. The announcement was made at a meeting of the Society for Microbiology (SGM), (September 5 2012. Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as corn or sugarcane. According to a research brief from the SGM, the DDGS material has been developed by researchers based at the University of Surrey to power microbial power cells. The science team took the DDGS together with bacteria-inoculated sludge from a waste water treatment plant and placed it into a specially designed fuel cell. Azom.com explain that the fuel cell was designed in such a way that the bacteria, which used the DDGS as a growth source, were physically separated from their oxygen supply. This meant that the bacteria were forced into sending electrons around a circuit leading to a supply of oxygen. By tapping into this electron flow, electricity could be generated from the waste. DDGS is a low cost ‘fuel source’ as it is an abundant waste products and as the biofuel industry expands the supply of DDGS will become more abundant. The DDGS is also relatively environmentally friendly (although there are wider socio-economic issues relating to the production of biofuels). DDGS also has an almost indefinite shelf life. The implication of the research is that self-powered devices could be developed which could be used to remove pollutants from water.