Yellow Power: Making Hydrogen From Pee
Instructions for using a urine separating toilet in Sweden
We do go on about the benefits of urine separating toilets, and how we have to redesign our plumbing systems to scale up dry composting and pee separation. It is a valuable resource because of the phosphorus, is sterile and easy to manage, and there is really no reason to mix it all up. Now we have another great reason to convert to urine separating toilets: It might become a great source of hydrogen.
Currently we get almost all of our hydrogen from steam reforming of natural gas, so it is really just another form of fossil fuel. The dream of the hydrogen economy was to get it through electrolysis from cheap clean electricity, but it just isn't very efficient; the hydrogen is really just acting as a lousy, hard-to-handle battery.
But according to Cleantechnica, you can get twice as much hydrogen out of urea from pee with a third of the energy than you do with water.
Chemistry World explains:
Using hydrogen to power cars has become an increasingly attractive transportation fuel, as the only emission produced is water - but a major stumbling block is the lack of a cheap, renewable source of the fuel. Gerardine Botte of Ohio University may now have found the answer, using an electrolytic approach to produce hydrogen from urine - the most abundant waste on Earth - at a fraction of the cost of producing hydrogen from water.
Urine's major constituent is urea, which incorporates four hydrogen atoms per molecule - importantly, less tightly bonded than the hydrogen atoms in water molecules. Botte used electrolysis to break the molecule apart, developing an inexpensive new nickel-based electrode to selectively and efficiently oxidise the urea. To break the molecule down, a voltage of 0.37V needs to be applied across the cell - much less than the 1.23V needed to split water.
Yellow is the New Green
There are so many good reasons to separate urine. Poop composts faster with less odor, both become valuable as different kinds of fertilizers, our lakes and rivers don't have to take all this stuff now we can even get a useful product.
The stuff is valuable, and it takes a lot of water to flush it away, and it costs a lot of money in infrastructure, maintenance and water purification. On the other hand we might actually make money selling it. As Gar Smith put it in Alternet:
If this all pans out, we may need to replace the phrase "piss-poor" with "urine-rich."
More on Pee:
Pee Power! Recycling Urine to Powder Makes Superior Fertilizer
Is Male Pee Better than Female Pee? The Compost Conundrum
Is Peeing in Public Green?
P is for Phosphorus (As Well As Human Urine)
Urinals Disguised as Trash Cans: Everyday Objects vs Anti-Social Behavior
Waste Not, Want Not: The Future of Toilets
Researchers Say 'Good To Pee On Tomato Plants' - Just Don't Let The Neighbors See