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Fuel cell running with urine

Biofuel cell converts human waste into electricity


Urine as an energy source: Researchers have developed a miniature fuel cell that can generate electricity from our liquid legacies. So far, the yield is rather low. But the technology has potential. Because in manufacturing the fuel cell is extremely low - and the urine, with which it is running, is environmentally friendly and is never scarce, emphasize the developers.

In the fight against climate change, the transition to renewable energy sources is an important element. Therefore scientists researching for years to more environmentally friendly alternatives to electric energy production - also in the field of fuel cell technology. Researchers have already developed a cell type that provides energy from alcohols and sugar without waste. Even a miniature fuel cell which uses as raw material self-molecules, has already been tested.


Electricity from urine

Scientists led by Jon Chouler of the University of Bath have developed a small microbial fuel cell that can convert the quasi constantly available waste from our body into energy: you reuse urine. "Microbial fuel cells have a great potential as a sustainable and green technology," the researchers write. The principle behind the bio cells: They use natural biological processes of microorganisms to convert organic substances directly into electrical energy.

To put this reaction in the urine in transition, Chouler and his colleagues used glucose and protein ovalbumin which is found in the egg white of birds' eggs. Both substances are used in the fuel cell as a biological catalyst. The advantage: Unlike the commonly used in microbial fuel cell catalyst platinum these substances are not only renewable, but also much cheaper - according to the researchers.


Cheap - and no harmful gases

But how much electricity can be generated with the urine-powered fuel cell? For the greatest possible effectiveness, the scientists experimented among others, the length of the electrodes. Already a doubling from four to eight millimeters could increase the yield by tenfold. Inserted it more fuel units along the current result rose proportionally.

According to Choulers team a single fuel cell produces so far, however, relatively little power: two watts per cubic meter. It can not be compared with other technologies such as hydrogen or solar-powered cells - but at least one could operate a mobile phone. "The great advantage of our fuel cell, however, is that their production is extremely cheap and it uses waste as fuel - waste which is never over and produces no harmful gases," the researchers emphasize.


Save power for poor and remote regions?

The scientists now want to try to optimize the design of their cell and so to improve their performance. "If we manage to exploit the full potential of this human waste, we could revolutionize the power generation," they write. Particularly useful fuel cells could thereby be for developing countries. Because the cell could bring a share price of between one and 2.50 euros electricity to remote and poor regions.

"Having a technology done that could possibly change the lives of poor people fundamentally, is an exciting prospect. I hope that our research can enable these people one day better living standards," concludes Chouler. (Electrochimica Acta, 2016; doi: 10.1016 / j.electacta.2016.01.112)
(University of Bath, 04/19/2016 - DAL)


Microbiological urine / DC converter?


Elektor-Verlag GmbH:


A new type of fuel cell is able to produce on "biological way" electrical energy. Here this fuel cell is particularly small. British researchers from the University of Bath, Queen Mary University of London and the Bristol Robotics Laboratory succeeded in developing a microbiological fuel cell that can be produced more cheaply and with less effort. The special feature: It works with urine as a "fuel".

Microbiological fuel cells use natural processes in bacteria, with organic material to generate electrical energy directly. Other natural energy conversion process would be for example the fermentation or gas generation. But microbiological cells have the advantage that they operate at room temperature and atmospheric pressure, and not only are inexpensive but also produce little waste here.

The new cell uses no expensive cathode materials, but carbon and titanium wires. In order to accelerate the biochemical reaction and to generate more power, a catalyst of glucose and ovalbumin is used (a protein). The latter may be recovered from waste in food production. The results were described in an article in "Science Direct".

In the future, not just any home has solar cells on the roof, but from every toilet and especially from animal feedlots lead thick power cord because power = money and the 2000 year old saying "... non olet" gets probably a new meaning.