Re: Hydrogen RET?

Water molecules have a number of different modes of vibration. Think of the oxygen with two hydrogen as a Mickey Mouse face and ears. The ears (hydrogen atoms) can move towards and away from the face (oxygen). The ears can stay the same distance from the face, but vibrate towards and away from one another. The whole thing can spin like a top, along three different axes.

Each of these modes will have a natural frequency (actually frequencies, I think these come from getting the associated electrons into various energy states). The molecule will typically be vibrating and spinning in every possible way at the same time, and also zooming through space (and generally bouncing off other molecules) as well. The velocity with which all this happens is a measure of the temperature of the gas.

The energy in any given vibrational mode will leak into the other modes over time, and the time over which this happens is short, on the order of one millisecond. Also, the hydrogen and oxygen atoms are charged because of the way the bonds redistribute their electrons. When these charged particles vibrate, they emit photons with their characteristic frequency. The molecule, as well as having a tendency to emit photons of those colors, is also better at absorbing photons of those colors.

One way to seperate hydrogen and oxygen would be to heat water to many thousands of degrees K, at which point the vibrational energy in the bonds would be sufficient to break those bonds. This is a very inefficient way to make hydrogen and oxygen. Also, your hydrogen and oxygen are now in a plasma, and you'll have to seperate them before you cool it down. If this is the Genesys idea, it's a joke.

However, just because energy tends to redistribute over all the bonds doesn't mean you always have evenly distributed energy. A laser is a specific example of a system in which you use photons to deliberately pump energy into particular modes and not others. A blue laser, for instance, comes from stuff at room temperature rather than blue-hot.

If you could hit the water molecules with photons tuned to one of the bonds, with intense enough light, you could pump enough energy in to break the bond before the energy had redistributed enough to become temperature. Now you would have seperated hydrogen and atomic oxygen at low temperature. Atomic oxygen is incredibly reactive, and you would somehow have to seperate the hydrogen from the atomic oxygen without it recombining into water, maybe with an electric field. This is essentially electrolysis. Maybe they have some way of making electrolysis more efficient by stimulating the reaction with tuned lasers.

Not that it matters. Ballard long ago coined the term "hydricity" to capture his fantasy that fuel cells would be so efficient at converting between hydrogen chemical energy and electricity that the two would be interchangable. And, at fabulous cost due to the use of exotic metals and ultraclean operating environments, efficiency can be had.

But hydrogen is a terrible energy carrier regardless of the efficiency of conversion. Consider just one of many problems: the cost of capital for a steel pressure vessel containing hydrogen at room temperature, for just one day, is a little more than the value of the hydrogen contained. So assuming you could get hydrogen for free and sell it at current market prices, you could only afford to contain it for a day. That means, no hydrogen equivalents of LNG tankers. That means, no long hydrogen pipelines (those are pressure vessels too). It basically puts the kibosh on any hydrogen infrastructure.