How biofuels are recycled for electricity

A waste product made from biofuels has been recycled to power fuel cells.

A waste product made from manufacturing biofuels has been modified to give it a second lease of life, recycled to power fuel cells and therefore low-cost electricity.

The by-product is called Distillers Dried Grain with Solubles (DDGS). It is created through the production of bioethanol, and is mainly used as a livestock food due to its high protein content. However, at the meeting of the Society for Microbiology (SGM) this month, a team of researchers from the University of Surrey, UK, said they have altered DDGS to make it suitable for powering fuel cells.

According to the research brief, treating DDGS with bacteria from sludge harvested at a waste water treatment plant and placing it into a custom fuel-cell resulted in electricity production.

The bacteria found in the waste-water sludge found itself physically separated from an oxygen supply. As a result, the bacteria was forced to send electrons around the power cell's circuit to reach an oxygen supply -- which meant the scientists could tap into the flow and produce electricity.

The team believes that the modified DDGS could become a low cost "fuel source", especially if the biofuel industry continues to expand, and therefore produces vast amounts of bioethanol waste. The fuel cells are cheap to produce, and as electricity extraction results in a lowered reaction with oxygen, the scientists say that it is fairly environmentally friendly.

"We've found something really useful from a waste product without affecting its value as animal feed and at the same time improving its environmental status.

This is something we place great importance on and within our group we have a team solely dedicated to reducing polluting potential," said Professor Mike Bushell, leader of the research.

Potentially, these power cells could be used in developing self-powered devices that could remove pollutants from water and monitor weather conditions. Bushell explained:

"Self-powered sensors in remote places such as deserts or oceans can be used to provide important data for monitoring weather or pollution. Other applications in focus for microbial fuel cells include treating waste water to produce green electricity and clean up the water at the same time."

Image credit: Lisa Buddrus


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