Pee is for power: Your electrifying excretions
http://www.newscientist.com/article/mg20727741.400-pee-is-for-power-your-electrifying-excretions.htmlBotte's brainwave was to use urine instead of water. By weight, urine contains roughly 2 per cent urea, and each urea molecule contains four hydrogen atoms, which, crucially, are less tightly bound to the molecule than the hydrogen in water. Splitting these bonds would require less energy, making hydrogen production more efficient.
Last year, Botte's team reported that they had been able to generate hydrogen from urine using an electrolytic cell with cheap nickel-based electrodes running at only 0.37 volts- much less than the 1.23 volts it takes to split water (Chemical Communications, 2009, p 4859). Pure hydrogen bubbled off at the cathode, while nitrogen and carbon dioxide formed at the anode.
Botte calculates that with more efficient electrodes, hydrogen could be produced from urine at a cost of less than $1 per kilogram. She thinks the technology could be useful wherever large numbers of people congregate and enough urine can be collected to make the process worthwhile. "An office building where 200 or 300 people work could produce about 2 kilowatts of power," she says.
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Another approach is to forget about hydrogen and use urine directly as a fuel. This is the approach being taken by Tao and his colleague Rong Lan, along with John Irvine from the University of St Andrews, also in the UK. Since 2007, the team have been developing a fuel cell that can produce electricity directly from urine (see diagram). No voltage needs to be applied to break down the urea; instead, a low-cost electrode makes the reaction happen spontaneously. The details of the electrode are still secret.
Wouldn't it be freakin' awesome if something like this is what finally put oil companies out of business?!
:)