Potentially huge news...scientist burns water.

[Perfect Stu]

http://green.yahoo.com/index.php?q=node/1570

Could make a once-in-a-lifetime impact on the economy and environment.

[GameMaster]

But not just ordinary water, SALT WATER!

[manasecret]

Not sure I can embed this one:

Watch the flame in action.

Since they haven't already stated outright that the energy out is more than the energy in, I bet it's not. Maybe with further research, but I'm keeping my hopes low.

[Angrist]

What Manasecret said. How much energy can salt water hold?

[manasecret]

Originally Posted by Angrist

What Manasecret said. How much energy can salt water hold?

That's not really the issue. If you get hydrogen out of it, there's plenty of energy in that. According to Wikipedia, the combustion reaction of hydrogen gas is

2 H2(g) + O2(g) → 2 H2O(l) + 572 kJ/mol

So we know the energy released is 572 kJ/mol, but it's hard for me to visualize a mole of anything. Look up or calculate how many moles of water are in a liter, you'll get 55.55 moles of H2O in one liter. So multiply the energy by the moles/liter

572 kJ/mol * 55.55 mol/liter = 31.77 MJ/liter

which according to Wikipedia is pretty close to the energy content of gasoline (34.6 megajoules per liter). Assuming my memory of chemistry calculations is right, that's a plenty of energy.

Or just look at this photo and you'll come to the same conclusion.


It matters more whether the energy needed to produce the radio waves that are performing the water electrolysis talked about here with the "water burning" is less than the energy received from the hydrogen.

[manasecret]

Hmmm after writing that last post I've been thinking maybe I figured out the potential of this discovery. If the RF signals to produce this electrolysis could be made by a small enough RF generator to fit into a car, then that would solve the problem of the density or "lightness" of hydrogen.

Hydrogen actually has much more energy per kilogram than gasoline or any similar fuel, but the problem is that hydrogen is very light. The density of hydrogen gas is so much less than gasoline that the energy content of H2 is a maximum of about 4MJ/L, compared to 34.6MJ/L for gasoline, even though there is much more energy in hydrogen gas per kg! This results in the well-known problem with hydrogen fuel cell cars, that it's very difficult to store enough hydrogen in one tank for a car to be able to travel long distances without having to refill the tank every 60 miles or so.

If, however, you could store the hydrogen fuel in something much much more dense -- say, for example, water, which is even more dense than gasoline -- and then use an RF generator to "unlock" the fuel by electrolysis, then you would solve the distance problem of using hydrogen fuel in cars.

Btw, I tried editing my last post but it wouldn't go through.

[Angrist]

Originally Posted by manasecret

2 H2(g) + O2(g) → 2 H2O(l) + 572 kJ/mol

That's exactly my point. You don't have H2 there, you already have H2O, the énd/wáste product of that reaction. What would the reaction be that gives energy from burning H2O? How do you even burn H2O?

IF what they're doing is seperating the 2 H2 from the O2 and then burning it... it's going in a circle, you'd turn it into 2 H2O again. Law of conservation of energy.

If they have another reaction, I can't imagine what it would be, not with my 5 years of chemistry classes.

[manasecret]

Originally Posted by Angrist

That's exactly my point. You don't have H2 there, you already have H2O, the énd/wáste product of that reaction. What would the reaction be that gives energy from burning H2O? How do you even burn H2O?

Yeah it's misleading, they aren't really burning water, just breaking it into H2 and burning that.

IF what they're doing is seperating the 2 H2 from the O2 and then burning it... it's going in a circle, you'd turn it into 2 H2O again. Law of conservation of energy.

Yep, that's what they're doing. They're performing the same-old, ho-hum electrolysis of H20 into 2 H2 and O2 that we've known how to do for decades. The exciting part is that no one has ever done it without sticking electrodes in there to do that.

If they have another reaction, I can't imagine what it would be, not with my 5 years of chemistry classes.

I know! And I think that's what's baffling the researchers. I'm excited to know what the reaction is.

[Angrist]

Yes, they electrolyze water to get H2, but only to store it for other use, not to produce energy. Again: law of conservation of energy.

Stupid comparison: the 2 main ingredients of apple pie are apples and flour. You can separate those 2, which will cost energy. When you smash the apples and flour together again, you get some energy, but it can NEVER be more than what it cost to separate...
Unless there's really something huge going on. Something atomic.

[manasecret]

Ah it clicked in my head what you mean. I was thinking if you use RF signals to split up H2O, and then burn the H2 which gives you H2O back, then you would have a never ending supply of fuel! Haha well that's not right.

SO yeah, if it is simply electrolysis, I don't see how this could be used as a fuel for a car. As another, perhaps more efficient way of creating H2, then it's certainly interesting. So the question is whether this is electrolysis or not, since they didn't say explicitly whether it is or not as far as I remember.