On this site someone’s posted a link to a video, as well as a copy of the patent, and correspondance with the inventor of a hydrogen generator that uses a combination of 5 seperate metals and water (with no electrical input) to generate hydrogen on demand. Given that the site’s dedicated to overunity, I’m dubious of the claims to say the least. Still, something similar has been suggested by reputable scientists, so it’s possible that it could work.
Dude, there is no way in the world that you can extract energy from water (in the shape of hydrogen or anything else) without putting in an equal - in practice, greater - amount of energy at some stage of the process. If you want hydrogen out of water without using electricity you need only dump sodium into it, but you will get out no more energy than it took to refine the sodium.
Yeah, I know, but as far as I can tell, the inventor is not claiming overunity for his invention.
You can generate hydrogen without electricity. Put the right chemicals together, and you get hydrogen. The thing is, the chemical reaction that creates the hydrogen depletes whatever chemical you are using, so it doesn’t last forever. Various metal oxides are used for this purpose.
Then what’s the selling point? The ability to turn a tap and get gas? We had one of those in our school chemistry lab - it’s called a Kipps Apparatus. Put two globes one above the other with a pipe leading from the top to the bottom and a gas-tap on the bottom. Put a solid reagent in the bottom and a liquid in the top (you could use calcium carbide and water for example). Turn the tap on, the reagents combine, you get gas (acetylene - or ethyne if you want to be picky - in this case). Turn the tap off, the gas build-up forces the water back up the pipe and stops the reaction.
I think we mostly used ours for hydrogen sulphide, though I forget what the reagents were.
Hydrogen is a bitch store in liquid form, and expensive to extract out of water. A cheap method of extracting it from water would enable the development of the hydrogen economy. You could fill your car with water and have it generate hydrogen on the fly.
Yes, I know. The point is that there is nothing new about having an apparatus that generates gas at the turn of a switch. Now if the reagents being used are easy to recover and reprocess, and cheap to manufacture in the first place, then we have a convenient means of transporting energy from the power station to the point of use - but that’s all we’re doing. See the previous discussion on aluminium and water.
I don’t know how expensive it is to get hydrogen from water via electrolysis.
With electrolysis, you pay for an anode and a cathode one time, the rest of the cost is simply electrical energy. When you use a chemical method, you have to keep replenishing the reagents in order to keep making hydrogen. Usually that means pumping energy into them to bring them from their raw low energy form to a higher energy form.
Since you’re not creating new energy with this, the reagents are where you store the energy that gets converted into free hydrogen. Don’t think that’s going to be a small amount, unless those reagents pack an incredible amount of energy in a little package, you’ll be filling up on reagents all the time, just like you do with gasoline today, except you’ll need a tank to put the spent reagent in, unless you’re going to dump it on the ground.
Rather than having an engine and fuel tank, you have an engine, reagent tank, spent reagent tank, water tank, and hydroplant to generate the hydrogen.
What’s funny is, if there’s anything in this cycle that CAN be recaptured and reused, it’s the water, not the reagent.
What the video shows is readily achievable. People may remember generating hydrogen from zinc granules in sulphuric acid at school. The electrochemical half-reactions are:
Zn ---->Zn[sup]2+[/sup]+2e zinc dissolving into the acid
and 2H[sup]+[/sup]+2e—>H[sub]2(g)[/sub] hydrogen ions in the acid gain electrons and bubble off
The first reaction takes place on the surface of the zinc, basically zinc metal atoms “jumping” into the solution and leaving a couple of spare electrons in the metal.
The second reaction also takes place on the metal surface, but not predominantly on the zinc. Instead it takes place on spots of impurity, usually lead. On ultrapure zinc, the rate of the second reaction is very low, the surface forms a layer of “stuck” hydrogen atoms.
With an anode of ultrapure zinc and an inert cathode of almost anything conductive (lead, carbon, platinum would all be good), you could make the thing bubble hydrogen with a simple switch linking the two together. So the video isn’t showing anything too special.
Now, onto the patent! I’ve only skimmed it, but these two extracts give me pause:
" While equation 26 represents an endothermic reaction, it is believed the exothermicity of the reactions in equation 25 compensates for this, making the combination of the two reactions energetically obtainable using the thermal energy supplied by ambient conditions. Of course the supply of additional energy accelerates the process."
" The net result of this process is exactly that which would result from the electrolysis of water. …[snip]… the reaction proceeds efficiently when the only energy supplied is ambient thermal energy. …[snip]… The colloidal metallic ion catalysts M[sup]+[/sup] and/or M[sub]r[/sub][sup]+[/sup] as well as the metal M[sub]c[/sub] and the acid are regenerated in the process, leaving only water as a consumable material."
So it looks like the device proposes to use ambient energy to split water into hydrogen and oxygen. Which is an electrochemical Maxwell’s demon, thermodynamically impossible! I think he should run the thing for a decent amount of time and see if the bubbling electrode gets smaller…
One other point. When you simply electrolyse water, you get hydrogen and oxygen. It’s hard to tell, since the video isn’t that great and there are a lot of reflections in the glasswork, but I don’t think there’s any oxygen bubbling off any of the other electrodes. (And hydrogen and oxygen can’t be bubbling off the same electrode, or the device wouldn’t be switchable.) Whereas if you produce hydrogen by reacting water with metal, you get hydrogen plus a metal hydroxide, which can remain invisible in solution. So I’d bet the bubbling anode is dissolving like crazy.
It’s possible the inventor of this thing is self-deluded, but, nasty old cynic that I am, it’s hard to see how his demo device could fail to demonstrate metal consumption. So I suspect it’s a con. Or else it actually works, which seeing as he has a demo should be easy to prove, and I’ll cheer as loudly as anyone else!
So do you have to wait for it to solidify before you can buy bitches there?
Like you I only skimmed the patent but came to the same conclusion. Essentially he is claiming excess hydrogen production from using a sacrificial metal (e.g. zinc). A bit like the cold fusion guys, it is easy to mismeasure or miscalculate results. Also in the patent there is an optional external power supply to boost rates, so that would muddy the results further.
Treat with extreme skepticism.
Or you could dispense with the calcium carbide, put a very small demon at the gas tap, and have him open it upon only when an occasional free hydrogen atom or molecule floats near. This is what my friend Maxwell used to do, though he could never get it working properly…