Taking the Pi$$!!

[simonpickard]

Check this out...

Urine-powered generator produces six hours of electricity per bathroom break -- Engadget

[resilientg]

Geez, if you can get that much power from urine, imagine how long your fridge could go off one good solid dump.

[simonpickard]

If you installed a water maker, drank a lot, and used this I wonder if we'd see the worlds first perpetual motion machine?!

[delatbabel]

separating the excretion's hydrogen with an electrolytic cell

Surely the separation process uses more energy than it creates?

[propellanttech]

Originally Posted by delatbabel

separating the excretion's hydrogen with an electrolytic cell

Surely the separation process uses more energy than it creates?

Actually, the process sounds interesting.

We must remember that urine has large amounts of ammonia in it. Ammonia is also flammable.

There may be more going on here, than what is advertised.

Neat idea though. The holding tank could recharge your batteries.

James L

[denverd0n]

Originally Posted by delatbabel

Surely the separation process uses more energy than it creates?

Obviously it has to. Conservation of energy--it's not just a good idea, it's the law!

The question is, where does that energy come from? As propellanttech suggests, it might be released from the ammonia in the urine in some way. I would be interested in more details about how exactly this works.

[mbianka]

Originally Posted by delatbabel

separating the excretion's hydrogen with an electrolytic cell

Surely the separation process uses more energy than it creates?

Details, details, details. Look it does not have to be economically green it just has to sound environmentally "green". Like a lot of "sounds to good to be true" announcements this may like others turn out to be just another over hyped green snake oil stunt. Maybe trying to get some money from Bill Gates and/or others for "further research". Let's see how fast this story fades away like so many "green" breakthroughs.
I only believe in sure things like the email I just got from someone in Nigeria that a long lost Uncle has left me a fortune and all I have to do is send some money to...

[propellanttech]

At no time did I say that I whole heartedly believe the claim. I just stated that if it was creating more fuel, than being consumed, there was more going on here, than just electrolysis. It has been proven that electrolysis doesn't produce more fuel than what is consumed.

But there may be more than that happening.

Also if you notice, it was at Maker Fair. If you don't know what that is, then you have an assumption which is incorrect.

Maker Fair is a place where people showcase their inventions. Not for profit, or for sale. It is an open information sharing situation. The bragging rights are what people go for, not for the money. They openly share the information to the world. The information is documented, where no one else can file a patent claim.

So these girls didn't do it for money, they did it to try and be environmentally friendly.

James L.

[onestepcsy37]

unfortunately there is no hard detail behind the claim. otoh, it might be possible to use 'free' sunshine to process the urine into hydrogen.

[cal40john]

More sloppy reporting. It's another reducing waste energy from existing industrial plants technology.
It is not a power source, it uses more energy than it makes.

From: African girls’ pee-powered generator raises questions - FutureTech on NBCNews.com

“What these kids are doing is taking urea electrolysis and making hydrogen and then using that hydrogen to make electricity,” Gerardine Botte, a chemical engineer at Ohio University who invented the urea electrolysis process, told NBC News when asked to comment on the generator.

Another concern is the implication that the students get more energy out of the urine than they use to prepare it in the first place. That isn't true, according to Botte.

“It is a high school project, so don’t take it [so seriously],” Botte said, suggesting the students work with an engineer to understand the technology and its appropriate applications.

For Botte, the technology is most practical as a way to make the wastewater treatment process more energy efficient.

[propellanttech]

Originally Posted by onestepcsy37

unfortunately there is no hard detail behind the claim. otoh, it might be possible to use 'free' sunshine to process the urine into hydrogen.

If you want more information look here:

Pee power! African teens create urine-fueled generator | Crave - CNET

The next to last paragraph explains something that I though may be happening.

James L

[tbodine88]

Apparently the hydrogen created is "pushed" into a gas cylinder, which is later fed to the generator. Something has to do the pushing, what?

http://makerfaireafrica.com/2012/11/...red-generator/

Still its admirable that they are doing something, plus the fact that they are young women is also marvellous.

[propellanttech]

Originally Posted by tbodine88

Apparently the hydrogen created is "pushed" into a gas cylinder, which is later fed to the generator. Something has to do the pushing, what?

http://makerfaireafrica.com/2012/11/...red-generator/

Still its admirable that they are doing something, plus the fact that they are young women is also marvellous.

I've given the situation some great thought. There is more going on here than what is being discussed.

First, ammonia has a boiling point of −28.012 °F. It is also quite flammable.

Now, most people know electrolysis produces Browns Gas. This is hydrogen and Oxygen.

What is really strange is if you research the operation of the ammonia refrigeration cycle, hydrogen is used in the process for the continuous loop (bonding-return side).

I can' even begin to think about all the different chemical reactions which may be happening. This is way beyond my level of chemistry.

So, before you totally discount the system, you may want to give it a break, unless your a PhD in chemistry.

I would never claim to believe in over unity......

James L

[micah719]

Emergency recharge kit: a sixpack of beer with a packet of salted peanuts for the electrolytes. And a bucket, of course. Wonderful things. Some people even build cars out of them.

[delatbabel]

OK, so there appear to be a bunch of confused people, so just to clear up some points:

We must remember that urine has large amounts of ammonia in it.

No, it doesn't. Ammonia is one of the common chemical or bacterial breakdown products of the nitrogenous compounds in urine (and in fact breakdown of many animal and plant products), but natively urine contains no ammonia.

Ammonia is also flammable.

No, it's not. Although there is technically an exothermic reaction when you burn ammonia, the temperature of that reaction (i.e. flame temperature) is lower than the ignition temperature of ammonia. So it doesn't count as flammable because attempting to light it isn't self sustaining.

In the presence of a catalyst such as platinum gauze, it will flame but it doesn't count as flammable by itself.

Now if they were chemically or bacterially breaking down urine and other bodily wastes (hrm, not to put too fine a point on it but urine isn't the best source) into methane gas and igniting that then they'd have something. That's a technique used in many places in the world, including the third world. In fact it's not uncommon to find a sewage treatment plan that runs entirely off the energy it generates from gases it produces from the waste it treats, and furthermore feeds excess energy into the grid.

But that's not what's happening here. What the claim is in the article is that they are electrolysing urine to produce a gas that's fed into a compressor to then feed an engine which powers a generator. The net energy output from that is bound to be negative.

You could power an engine from the methane gas produced by chemical breakdown of urine, but 1L of urine wouldn't produce a significant amount of methane and hence wouldn't power the generator for very long. Typically waste-gas generators run from hundreds or thousands of tonnes of human or animal waste.

Now, most people know electrolysis produces Browns Gas.

Actually, no, most people don't know that, because it's nonsense science. "Brown's Gas" is a pseudo-science name for a mixture of hydrogen and oxygen. Those gases can be produced separately from electrolysis depending on the liquid you're electrolysing, but in general electrolysis doesn't produce anything known as "Browns Gas".

If you see those ads for devices that you fit to your engine that break down fresh water into "HHO" or "new forms of water" or other such nonsense compounds, well really all they do is use electrolysis to break down water into Hydrogen and Oxygen, recombine it and feed it into your engine. The net energy used to break down the water is in theory exactly equal to the net energy released in recombining the two, because of conservation of energy, but in fact in a not-perfect system there will be some energy leakage and in fact it doesn't gain you fuel efficiency but it costs you fuel efficiency (because the extra energy used by your alternator to generate the electricity to electrolyse the water is less than the energy you get back by recombining it in your engine).

It's analogous to the process being described in the article. If you break down water into hydrogen and oxygen, and then recombine it into water (which happens in the engine) then in theory the energy gained is exactly equal to the energy used. In practice the energy gained is less than the energy used because of inefficiencies in the system (show me a 100% efficient light bulb).

In early welding devices (19th C) it was common to use a mixture of Hydrogen and Oxygen to weld, however storage and use of the combination is highly unsafe. Modern techniques have switched us to acetylene and other gases instead, which produces much the same result but is safer.

What is really strange is if you research the operation of the ammonia refrigeration cycle, hydrogen is used in the process for the continuous loop (bonding-return side).

Umm, yeah, but that's a completely different process -- physical (condensation and evaporation of gases) rather than chemical.

So, before you totally discount the system, you may want to give it a break, unless your a PhD in chemistry.

Not a PhD but I do have a science degree.