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Aluminum Alloy Releases Hydrogen From Water
mdsolar writes "PhysOrg is reporting on a method of releasing hydrogen from water by oxidizing aluminum in an alloy with gallium. In the presence of water the aluminum oxidizes, leaving aluminum oxide, gallium, and hydrogen gas. The Purdue scientists who discovered the effect think this could help to overcome difficulties with hydrogen storage. Quoting: 'On its own, aluminum will not react with water because it forms a protective skin [of aluminum oxide] when exposed to oxygen. Adding gallium keeps the film from forming, allowing the aluminum to react with oxygen in the water.'"
Check the price on gallium. It's about $500 per kilogram, although there was a price spike a few years back and it passed $1000. It's a trace component in bauxite and coal. Way too expensive to be used as a fuel component.
Gallium is so expensive that it's not even cost effective in solar cells, where it works very well.
The aluminum smelting process requires vast amounts of electricity.
quoting a random googled page : "On average, around the world, it takes some 15.7 kWh of electricity to produce one kilogram of aluminium from alumina. Design and process improvements have progressively reduced this figure from about 21kWh in the 1950's."
so it doesnt matter that it produces hydrogen. It's almost assured coal equivalent to or greater than the tank of gas it replaces was burned somewhere to get the aluminum.
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It's not a closed system because it requires energy to recycle the aluminum and gallium. Also, it's still not terribly efficient, since it requires 1 lb of aluminum per mile you drive.
Tell the truth and you won't have so much to remember.
I used to work in a uranium mine is south-western Colorado. There are still many, many mines there that have lots of uranium in them. It just isn't economical to mine them as we don't really use that much uranium. If we built more power plants and the price came up, those mines would open.
No matter where you go, there you are. So Enjoy it.
No, it won't. The aluminum oxide is *hard* to convert into aluminum. That's the *reason* aluminum is expensive -- not because the oxide is expensive (it's dirt cheap), but because it takes *massive* amounts of energy to turn it back into aluminum. And, said energy has to come in the form of electricity. This is just an expensive way of storing and moving electrical energy -- and an inefficient one, too, when you remember that only some of the energy in the aluminum goes into cracking the water, and about half of it goes into heat.
Wikipedia has an article on the Hall-Héroult process, the major method used to refine aluminum oxide into aluminum. Ill save you the time.
"In the Hall-Héroult process alumina, Al2O3 is dissolved in a carbon-lined bath of molten cryolite, Na3AlF6. Aluminium fluoride, AlF3 is also present to reduce the melting point of the cryolite. The mixture is electrolyzed, which reduces the liquid aluminium. This causes the liquid aluminium to be deposited at the cathode as a precipitate. The carbon anode is oxidized and bubbles away as carbon dioxide. The electrical current used by many smelters, has a very low voltage, but massive amperage. This is typically 3-5 volts, but 150,000 amperes."
So now were back to greenhouse gasses and massive amounts of electricity.
Aluminum oxide is an incredibly energy-intensive process... and not altogether clean, either. You have a molten cryolyte bath that you dissolve the alumina into you have fluorinated waste gasses, you slowly dissolve your carbon anodes, etc. Water electrolysis is so much simpler, and quite efficient to boot. The only real downside is the thermal losses if your electricity comes from a heat-driven power plant, but that applies to most any process that uses electricity.
Anyways, without knowing the energy efficiency of this aluminum+water->hydrogen+alumina, I wouldn't be ready to judge this tech yet.
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Three things make this a nonissue. Breeder reactors can extend this significantly; it's referring to only current mining methods; there is far more that can be extracted with increased effort; thorium can be bred into fuel and there's way more thorium than uranium. By the time all these options are used up, the ITER project's fusion offspring would have long been in operation.
"Politicians and diapers must be changed often, and for the same reason."
ITER will not get break even fusion on a commercial scale. just like it's predecessors. It may get controllable fusion, but it will not make break even and the costs of the energy out will be huge. Commercial failure.
But everybody involved has to paint the smiley face and if you don't well then you obviously are not a serious researcher and you do not get funding. Double if your research threatens the research dollars tied up in ITER.
ITER is trying to perform bench experiments on a huge scale with little or no proof the ideas behind it are workable. All the previous experiments using this design have failed, nice data, no results. They need to scale back and experiment on equipment that doesn't cost a fortune per shot.
They have all these experiments just to gain containment, then _if_ they get that a lot more to gain control, then they might try to light the fuse, _if_ they have containment and control. They're not sure they are going to get either and yet they want me to believe they know they are going to get commercial power.
What stands out to me is how much money and publicity is given to the supporting systems, it's like they've gone ahead and done the engineering before they've done the science. In successful projects very little is spent on engineering as it's all funneled into the science. Engineering is what you do when you know what you are doing. First you get the science working then you work on the engineering challenge.
It's a bunch of egghead egos playing with super sized Lego and trying not to let on they don't have a clue.
Aluminium is extracted via electrolysis and takes masses of electricity to produce. Hope you're adding this energy into your "zero sum".
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