Posted on 07/07/2009 8:23:59 PM PDT by neverdem
US researchers have developed an efficient way of producing hydrogen from urine - a feat that could not only fuel the cars of the future, but could also help clean up municipal wastewater.
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.
Botte says the idea came to her several years ago at a conference on fuel cells, where they were discussing how to turn clean water into clean power. 'I wondered how we could do this better,' she adds - so started looking at waste streams as a better source of molecules from which to produce hydrogen.
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.
|
Electrolysis breaks down the urea, releasing hydrogen
|
'During the electrochemical process the urea gets adsorbed on to the nickel electrode surface, which passes the electrons needed to break up the molecule,' Botte told Chemistry World. Pure hydrogen is evolved at the cathode, while nitrogen plus a trace of oxygen and hydrogen were collected at the anode. While carbon dioxide is generated during the reaction, none is found in the collected gasses as it reacts with the potassium hydroxide in the solution to form potassium carbonate.
The group initially tested their process with 'synthetic' urine made of dissolved urea, but also showed that the process works just as well with real human urine. 'It took us some time to get clearance to work with human urine - which held up publication of the research,' says Botte.
According to Botte, currently available processes that can remove urine from water are expensive and inefficient. Urea naturally hydrolyses into ammonia before generating gas phase ammonia emissions. These emissions lead to the formation of ammonium sulphate and nitrate particulates in the air, which cause a variety of health problems including chronic bronchitis, asthma attacks and premature death.
The group are currently conducting long term stability studies on their electrolysis systems, as well as conducting computational experiments to better understand the mechanisms at work.
Botte believes the technology could be easily scaled-up to generate hydrogen while cleaning up the effluent from sewage plants. 'We do not need to reinvent the wheel as there are already electrolysers being used in different applications.' She believes the only the thing that would hamper the process would be the presence of a lot of salt.
Bruce Logan, an expert in energy generation from wastewater and director of Pennsylvania State University's H2E Center and Engineering Environmental Institute, applauded Botte's efforts in developing a more energy efficient way of producing hydrogen than splitting water. However, he did caution that urea gets converted very quickly into ammonia by bacteria, which could limit the usefulness of the technique.
However, Logan does feel that it would be a good idea to start saving up our urine - although not for the hydrogen. 'You have to remember about the P [phosphorus] in pee - globally we need to start thinking about conserving phosphorus for fertiliser, because, just like oil, one day the deposits are all going to run out and we need to start building phosphorus recycling into our infrastructure,' he says.
Matt Wilkinson
B K Boggs, R L King and G G Botte, Chem. Commun., 2009, DOI: 10.1039/b905974a
That is correct
I think this is a great process and I’m just tweaking the enviromentalists ;0).
Sodium and chloride ions are electrolytes in aqueous solutions. If it precipiates as a solid, I think it might muck up cathode or anode performance.
Its all a matter of degrees(if you will forgive my Global warming terminology)..
We have been through all this science. Nuke has the highest yield.
Regular Hydrocarbons are next in efficiency.
I see your point.It is amazing, that I have to rehash a subject I took years ago.
Nobody could be that stupid.
A nickel battery using piss as the electrolyte.
At $270 a ton the urea and the nickel costs far out weigh
the electricity costs for electrolysis.
First they came for the corn.
Now there going to come for the fertilizer?
But they refuse to drill for the oil.
I dont know. Its been 25 years since I studied J shells and K shells and the transfer of energy and all that physics.
All I know is that we just keep reinventing the wheel.
I havent seen anything that will replace hydrocarbons except perhaps ,pebble bed reactors
Solar panels and wind sure aint gonna do it.
They are inefficient.
The typical IC engine is only 16-17% (at full load) efficient.
Instead of working on better fuels (one of the limiting factors) and less waste heat
their playing with piss.
We have a long way to go. Abandoning hydrocarbon fuels
is ridiculous.
"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. "
No matter how much free piss you have, take away the subsidies, and this technology is worthless.
Last time that I checked, we're paying taxes for waste disposal in most municipalities.
You don't get something for nothing.
I'll take free energy anytime.
Diesel has been efficient from day one
Synthetic diesels are clean and have tremendous potential.
http://www.shell.com/home/content/aboutshell/our_business/oil_products/fuels/gtl/gas_to_liquids.html
Even regular diesel
Compared to what it could be.
There is massive room for improvement.
Better fuels, higher compression, longer stroke
for heat Scavenging and better combustion.
One would have to see it to believe.
ROFLMAO....all the men with BPH are going to get RELIEF!!!!!!!!...er....BE relieved!!!! (I just spent 8 hours in a car with one today!!!!) Even if this wouldn’t work.....it’s been worth the laughs....
Don't folks take physics anymore?
Nothing will ever replace oil, and there's plenty of if out there.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.