New Source of Fuel for Your Generator
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Grisu
Minister of Fire
Sure, and the next thing we do is running our cars on pee. 
"Urine is put into an electrolytic cell, which separates out the hydrogen." Unfortunately, they do not explain where the energy for the electrolysis is coming from. Neither do they mention that this energy would power their lightbulb for much longer. I love those ingenious inventions that seemingly rewrite the laws of physics. 
"Urine is put into an electrolytic cell, which separates out the hydrogen." Unfortunately, they do not explain where the energy for the electrolysis is coming from. Neither do they mention that this energy would power their lightbulb for much longer. I love those ingenious inventions that seemingly rewrite the laws of physics.
Grisu
Minister of Fire
Ok, I was somewhat wrong. According to this paper ( http://www.suttonfruit.com/pics/urea_electrolysis.pdf ) which is the basis for the girls invention the urea in the urine is hydrolyzed. Thus, from one liter of urine you should get 1 mol = 1 g of hydrogen under optimal conditions. The oxidation of 1 mol hydrogen gives you 285 kJ of energy. With that amount of energy you can power one 80 W lightbulb for one hour. However, sine they pipe the hydrogen in a generator their efficiency goes down to maybe 30% so a 25 W lightbulb for an hour sounds more likely. Accordingly, in the paper they suggest using this mechanisms to get rid off the urea in water treatment plants while at the same time generating something useful.
The process was already known. The impressive thing is that the young ladies in a third world country put it to work. I don't care if it took ten times the energy generated. If they need electricity to hydorlize the the pee then stick a solar panel on the outhouse.
Not to be pessimistic, but it can't be producing very much electricity. It would be hard to run a generator 6 hours on a liter of gasoline...much less a liter of 'water'. Given stacked up efficiencies (highly optimistic)....combustion engine driving an electric generator (30%), electric generator driving an electrolytic cell (70%), electrolytic cell making hydrogen which is piped back to the combustion engine (50%) - that is an overall efficiency of 0.3 x 0.7 x 0.5 = 10% So it really couldn't make enough electricity to power itself, much less supply power to regenerate it's filters and borax drying agent. Unfortunately it seems like they are pushing the same old 'HHO' scam...just with an entirely new substance.
Grisu
Minister of Fire
It is a third world country but their school does look better than some highschools here: http://www.stbeslagos.org/schools/dpa
Considering all the specialized equipment and chemicals they need the girls cannot come from some school out of the slums. It is a nice and impressive feat of engineering for some teenagers to get it to work. Too bad, it comes off as the next energy revolution.
Pee-Power for the Uri-Nation? No need to add salt.
It's a cool use of available materials. Solar energy for electrolysis is totally feasible in sunny areas of the world.
It's a cool use of available materials. Solar energy for electrolysis is totally feasible in sunny areas of the world.
Grisu
Minister of Fire
The materials they used made me a bit skeptical. A nickel catalyst? Concentrated potassium hydroxide? Not something you would expect in a normal school of a third world country.
Sure, but then hydrogen becomes just an energy carrier and a poor one to boot. Highly volatile, explosive when mixed with air, needs further compression or liquification, specialized storage tanks etc. When you then use it in combustion engines your solar energy becomes about 4% efficient at best. Although batteries have their drawbacks they are still way more efficient when you want to store electricity from solar.
And light from a light bulb was impossible until somebody failed the first few hundred times. Always working on the same old things that make "sense" doesn't always make sense. Not arguing for or against, simply stating that we shouldn't tell somebody they "can't".
Criminy, I don't think there's anyone anywhere who believes that this is the answer to the world's future energy needs. What the hell's with all the negativity and nay-saying. The girls are learning and thinking and doing...that's what's important about this story so far as I'm concerned. I'm impressed by these young students a good deal more than I am with the potential of this particular project they put together. OK, it's not particularly feasible. Got it. But who knows what these girls will go on to develop next? YOU GO GIRLS!
Grisu
Minister of Fire
I do not disagree with you at all about that. It is certainly an achievement although I do not understand the hype around it. I am just skeptical whether a story about some other girls in the same fair developing a new kind of cooking stove that cuts emissions by 20% would have garnered the same worldwide interest. Or take an exotic homebrew that deters mosquitos for hours and could be a major factor against malaria. Both achievements would have much more practical ramifications.
If this story was posted for the "social interest" value then it would be better placed in the inglenook IMHO. Here in the green room it will be scrutinized.
Grisu
Minister of Fire
I am a little bit surprised that this comes from you, Jags, as you should now that there are physical limits that just cannot be exceeded. I would tell anyone working on a perpetuum mobile that this is a waste of time. An electric heater will never be more than 100% efficient despite all the claims of "super-efficient" Amish heaters and similar. Maybe some day an internal combustion engine will reach 50% efficiency but I will take any bet it will never reach anything close to 100% as combustion implies waste heat generation. If you work on something you should now which limits you want to redefine. Physical laws, technological limits or practical limits? Pratical limits means the technology exists but it is not yet feasible large scale. Technological limits mean you have not invented the technology yet to achieve what you want. Physical laws mean you want to overcome limits that are defined by our physical world and rewrite science. I look at inventions through that lens and then judge accordingly. The light bulb was certainly a great invention but that was a mere technological limit not a physical one.
Even risking some serious flaming but here is a quote of Ronald Reagen that is just utterly BS:“There are no such things as limits to growth, because there are no limits on the human capacity for intelligence, imagination and wonder.” There are limits; just try to image a 4-dimensional room.
I leave with this quote:
“At the heart of science is an essential balance between two seemingly contradictory attitudes–an openness to new ideas, no matter how bizarre or counter-intuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense.”
Carl Sagan
Grisu - I completely understand the angle that you are coming from and I see your points. But also understand that many big breakthroughs come from a garage somewhere. What if......
What if...because they are young....the test was contaminated with frog dung from a frog only found there....and it was a catalyst to breaking hydrogen free like nothing we have found yet? Yeah, I know its ridiculous, but what if....
What if...because they are young....the test was contaminated with frog dung from a frog only found there....and it was a catalyst to breaking hydrogen free like nothing we have found yet? Yeah, I know its ridiculous, but what if....
Grisu
Minister of Fire
Unfortunately, physical chemistry will simply tell you that is not possible. Do you know the difference between an exothermic and an endothermic reaction? To stay with water: Burning hydrogen and oxygen to get water is exothermic meaning you will get energy out of the reaction. On the other hand, electrolysis of water to get hydrogen and oxygen is endothermic. You will need to put energy in to get the two. In a perfect scenario the energy you will need to put in is the same as the energy you will get out. If you simply look at the enthalpy the energy you will get out is 285.83 kJ per mol of water. That same amount you need to put in to get hydrogen and oxygen. (It is actually a bit more complicated for water due to the liquid to gas transformation; see here: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/electrol.html )
What does a catalyst do? A catalyst reduces the amount of energy needed to get a reaction started. You can actually mix hydrogen and oxygen and nothing will happen until you put a spark in. That spark is the activation energy needed to get the reaction going. It is tiny for that strong exothermic reaction but still needed. A catalyst would be a substance that you add to the mixture and water would spontaneously form at room temperature without supplying any additional heat. The catalyst would not be consumed during that process. Almost all catalysts work on exothermic reactions; they just reduce the barrier to get the reaction going. Thus, I can tell you there will not be any catalyst that will magically dissociate hydrogen and oxygen from water. Now, what you can work on is making electrolysis more efficient as it is currently at only about 85% efficiency. I saw recently a paper where they got to almost 100% with a special electrode. If that is true we will have maxed out the system. Looking for further improvements will be rather pointless.
I am also a bit skeptical about the garage thing. That may have been true more than 50 years ago when there weren't that many laboratories around but nowadays big breakthroughs come from dedicated research labs and companies. Technology has advanced so much that the possibility of one individual singlehandedly rewrite physics/chemistry etc. is rather remote IMO.
Seasoned Oak
Minister of Fire
Seasoned Oak
Minister of Fire
Dune
Minister of Fire
You pick the one thing Raygun was ever right about as an example?
Sorry you can't imagine something as simple as a four dimensional room. Must suck.
Dune
Minister of Fire
So Apple is more than a 50 year old company? What a staggering counterproductive outlook you have.
Thank you for taking a ridiculous, off the cuff silly example (really? Frog poop?) and using it to prove your point. I agree with Dune - that 3 dimensional box you live in must be real tidy.
http://inventorspot.com/articles/top_10_2010_popular_sciences_garage_invention_awards_42299
Edit: Grisu, as I re-read my post it comes off a bit harsh. Not intended that way. I envy and all but worship scientists, inventors, etc., but sometimes getting out of the box reveals new ways of thinking. That is a good thing.
http://inventorspot.com/articles/top_10_2010_popular_sciences_garage_invention_awards_42299
Edit: Grisu, as I re-read my post it comes off a bit harsh. Not intended that way. I envy and all but worship scientists, inventors, etc., but sometimes getting out of the box reveals new ways of thinking. That is a good thing.
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