A revolutionary new fuel cell could take in urine and produce electricity and clean water. It might sound silly, but a prototype already exists, and it could provide the unlikeliest possible solution to third world energy and clean water problems.
Fuel cells convert chemical energy into electricity through a series of reactions between a fuel and an oxidant. Fuels can include hydrogen or methanol gas, while the oxidants are usually, unsurprisingly enough, oxygen, although chlorine is also sometimes used. Unlike conventional batteries, they don't store any chemical energy inside them, and so only operate when external fuel sources are supplied.
In theory, fuel cells could be a powerful producer of electricity, but their designs are often impractical. Hydrogen is highly flammable and methanol is toxic, creating major challenges in safely storing the required fuels. Also, some fuel cells require membranes and catalysts built from platinum, which obviously drives up the cost.
But the Carbamide Power System might just offer an alternative. The brainchild of Doctors Shanwen Tao and Rong Lan, this new fuel cell uses cheaper materials for its membrane and catalysts, and it uses a non-toxic, non-combustible fuel: urine. Specifically, a component of human and animal urine known as urea, which is currently mass-produced as an industrial fertilizer. Urea is also known as carbamide, which is where the new power system gets its name. (For some reason, Tao and Lan felt Urea Power System didn't have quite as nice a ring to it.) And yes, it's possible to substitute actual urine in place of the urea, as you can see in the diagram from their wonderfully named company, Youtricity.
Dr. Tao explains where he first got the idea:
"Growing up in rural eastern China I was aware of the use of urea as an agricultural fertilizer. When I became a chemist and was looking at fuel cell development I thought of using it in the process. We are only at prototype stage at present, but if this renewable material can be used as a commercially viable and environmentally friendly energy source then we will be absolutely delighted, and many people around the world will benefit."
Because urea is being used in trucks and other heavy-duty vehicles to reduce nitrous oxide emissions, there's already a fueling infrastructure in place for the cells. Dr. Tao says submarines and other military vehicles could definitely make use of these cells, as could isolated regions without ready access to other forms of energy, such as deserts and islands. With a little tweaking to the design, the fuel cells could also create clean, reprocessed waste water as a byproduct of their electricity creation.
Although it's not there quite yet, a device that can take in urine and produce electricity and clean water is the sort of thing that really could change the world for the better - even if you'd rather not think about where that water and electricity is coming from.
[Via Heriot-Watt University]