Scientists flushed with success after "sprinkle-power" breakthrough
Scientists have published the world's first research paper on work that tested the viability of urine as a potential fuel for Microbial Fuel Cells (MFCs) in order to directly produce electricity.
Dr Ioannis Ieropoulos, Professor John Greenman and Professor Chris Melhuish (Bristol Robotics Lab, UWE Bristol) have outlined research carried out to look at whether urine could be used as a fuel by the MFCs and how much power could be generated by MFCs using urine in this way.
MFCs consist of two half-cells - an anode and a cathode - that are separated by an ion selective membrane. Commonly bacteria are in the anode side, and chemicals or oxygen are in the cathode side, which complete the reactions (i.e. close the circuit) to generate power.
So far the use of urine as a biomass that can be converted to power via MFCs has been neglected by scientists, despite the fact that urine is an abundant waste product. Each human produces approximately 2.5 litres of urine a day, amounting to around 6.4 trillion litres globally each year.
Dr Ioannis Ieropoulos explains, "Urine is chemically rich in substances favourable to the MFCs. Our research found that the output of electricity was consistent and measurable depending on the volume of urine and the timing of the doses. At the moment the output from one MFC is small. Through this study and the related work carried out by our group over the years, we were able to show that by miniaturisation and multiplication of the number of MFCs into a stack and regulating the flow of urine, it may be possible to look at scales of use that have the potential to produce useful levels of power, for example in a domestic or small village setting.
Image credit: http://ejournal.vudat.msu.edu/index.php/mmg445/issue/view/4