Is 'Urine Power' real?

[padren]

I don't want to hijack the alt energy thread, and I can't figure out if this is bad science, or good science that just totally elludes me.

 

http://dsc.discovery.com/news/2009/07/08/urine-power.html

 

Urine-powered cars, homes and personal electronic devices could be available in six months with new technology developed by scientists from Ohio University.

 

Using a nickel-based electrode, the scientists can create large amounts of cheap hydrogen from urine that could be burned or used in fuel cells. "One cow can provide enough energy to supply hot water for 19 houses," said Gerardine Botte, a professor at Ohio University developing the technology. "Soldiers in the field could carry their own fuel."

 

That's a pretty hefty claim - though I have no idea what the actual amounts of electricity are that they are talking about.

 

Chemically binding hydrogen to other elements, like oxygen to create water, makes it easier to store and transport, but releasing the hydrogen when it's needed usually requires financially prohibitive amounts of electricity.

 

By attaching hydrogen to another element, nitrogen, Botte and her colleagues realized that they can store hydrogen without the exotic environmental conditions, and then release it with less electricity, 0.037 Volts instead of the 1.23 Volts needed for water.

 

The first paragraph is facepalm-worthy since releasing hydrogen is not financially prohibitive but prohibited by the law of conservation of energy considering the result of using hydrogen to generate electricity is water.

 

However, it appears based on those numbers you could expect to get a considerable amount of 'bang for your buck' on hydrogen/nitrogen if it is accurate. The part I have a hard time understanding is:

 

1) We don't get any energy out of drinking water. The body can only either use H2O in that form or expend energy to break it down, the only energy we can get then is from food.

 

2) The article claims that "A fuel cell, urine-powered vehicle could theoretically travel 90 miles per gallon." which means to me that there would have to be a tremendous amount of energy not harnessed in the food we consume that is still there when it becomes waste. I may just not be familiar with how much energy does go into food but it seems that people can subsist on pretty low-energy diets and I have a hard time believing the left over energy could be there. That of course is just my perception, and not based on any facts so I am curious about this.

 

Is this for real? Anyone have ideas of the actual numbers in terms of energy etc?

[Mr Skeptic]

My guess is they're talking about ammonia. Ammonia is fairly easy to store, and I think can be broken down to nitrogen and hydrogen. If so, the hydrogen could then be fed to a regular fuel cell.

[JillSwift]

They're talking about urea. ((NH₂)₂CO) It can be broken down by electrical current, and it will release hydrogen gas - a significant amount of energy in that hydrogen than was expended in releasing it.

[padren]

They're talking about urea. ((NH₂)₂CO) It can be broken down by electrical current, and it will release hydrogen gas - a significant amount of energy in that hydrogen than was expended in releasing it.

 

Based on the cited info that it can be released with "0.037 Volts" does that mean the hydrogen can captured and power a fuel cell with the sort of returns they describe in the article? First, I have no idea what "0.037 Volts" means - ie, how much hydrogen is released. They claim though that a gallon can power a car for 90 miles - but they don't say if it takes 100 gallons of urine or just over 1 gallon of urine to produce the urea. They also say a cow can heat water for 19 homes yet that is also a pretty ambiguous metric.

 

Does the body's capacity to produce urea actually result in a real harnessable power of notable amounts? I'm trying to nail down the values because I find the idea that biological systems create such power accumulation pretty fascinating, if the numbers hold up.

[Cap'n Refsmmat]

Here's the original journal article on the topic:

 

http://www.rsc.org/delivery/_ArticleLinking/ArticleLinking.asp?JournalCode=CC&Year=2009&ManuscriptID=b905974a&Iss=32

 

Using these voltages for comparison, we found that 30% less energy is required for urea electrolysis, which generated 36% cheaper hydrogen compared to water electrolysis.

 

So they're just saying urea is easier to split with electricity than water is.

[Mr Skeptic]

I suppose that means that you could use your hydrogen fuel cell to get hydrogen from urea electrolysis and still have a little energy left over. However, this seems like it would be pretty dumb considering the percentage of energy from the fuel cell that would have to be dedicated to it. Though I suppose that could be done while idling or parked.

[Severian]

Is this for real? Anyone have ideas of the actual numbers in terms of energy etc?

 

I don't think so. I think they are just taking the piss.

[JillSwift]

I don't think so. I think they are just taking the piss.

Ha! ==

[Mokele]

Remember, organisms actually invest energy in making urea (or uric acid in those species that excrete that) from the natural product of protein breakdown, ammonia, due to the toxic properties of ammonia.