Two years ago, researchers in England insisted their work on a microbial fuel cell that would use urine as a fuel was “not another MFC study that simply demonstrated the utilisation of a substrate.”
“The impact from this could be enormous,” they declared.
Now the team is reporting that, indeed, rather than washing their hands of the concept, they have made a steady stream of progress – to the point where they can power small devices, such as a mobile phone.
“We are very excited as this is a world first,” Ioannis Ieropoulos of the Bristol Robotics Laboratory said in a statement. “No-one has harnessed power from urine to do this so it’s an exciting discovery. Using the ultimate waste product as a source of power to produce electricity is about as eco as it gets.”
Mind you, there is still work to do here: The amount of power the researchers report producing is modest at this point.
“So far the microbial fuel power stack that we have developed generates enough power to enable SMS messaging, web browsing and to make a brief phone call,” Ieropoulos said. “Making a call on a mobile phone takes up the most energy but we will get to the place where we can charge a battery for longer periods. The concept has been tested and it works – it’s now for us to develop and refine the process so that we can develop MFCs to fully charge a battery.”
As we reported back in November 2011, researchers trying to advance this microbial fuel cell technology have played with carbohydrates, fatty acids, alcohols and whatnot as fuels, but until this bunch in England came alone apparently nobody had tried urine – cheap and abundant urine, it goes without saying.
The researchers found that the uric acid, creatinine and small peptide molecules found in urine, catalyzed by some of the same bacteria used in wastewater treatment plants, actually worked: In the anaerobic environment of the fuel cell’s anode chamber, the bacteria transfer the electrons obtained by breaking down the urine to an electrode, beginning the current-generating process.
Ieropoulos describes how the MFC works in this video produced by the Bristol Robotics Lab:
According to the University of the West of England, this urine-fueled MFC research has been funded by the Engineering and Physical Sciences Research Council (EPSRC), the Gates Foundation and the Technology Strategy Board. The paper reporting successful charging of a commercially available mobile phone, “Waste to Real Energy: the first MFC powered mobile phone,” was published in the Royal Society of Chemistry Journal of Physical Chemistry Chemical Physics.