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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.'"
Just another way of converting electrical energy into a form that can be used later.
We need to have a source of reliable cheap electricity to make the aluminum. And we don't at this time.
Dog is my co-pilot.
While I applaud the science, I doubt this is the "hydrogen revolution". It seems to be that we're suddenly talking about powering our cars with water (cheaply available) and massive blocks of a aluminium/gallium alloy. The article seemed to put forward the view that water was the fuel and the alloy acted as a catalyst. While this is indeed CHEMICALLY what is happening it's the cost of the catalyst driving (no pun intended) the reaction that's going to keep this off shelves for a while.
When/if they come up with a method for reactivating the alloy which is a) cheap and b) simple, then you can colour me interested.
Godless heathen.
So their process uses as much power as they put in and they are basically hoping for free electricity to make it commercially viable. Because the anti-nuclear wackos are never going to let nuclear reactors to be built *anywhere at all*, the chances of building one cheaply is nil. Some folks even object to windmills and will tie then up in litigation forever. So forget that too. That leaves coal, natural gas, and oil (or hydro - but we don't build damns anymore, because it hurts the fish).
They might as well use the imaginary nuclear reactors to directly power electrolysis of water and skip the aluminum. I'm not sure that hauling around several hundred pounds of aluminum beads is any easier than hauling around compressed hydrogen.
Making aluminium out of any aluminium ore (including oxides) takes big frickin' huge amounts of energy.
Wake me again when they have found some sort of catalyst that works with the reaction
2 H2O + (some sort of cheap, abundant energy, preferably heat or sunlight, definitely not electricity) -> 2 H2 + O2
Well the mainproblem is that using hydrogen is only a way to store energy, if you use electrolysis.
But electrolysis for it self has a bad efficiency (if you combine
input output 0.5*0.5 = 25%) , that´s why 90-95% of the Worlds hydrogen needs are satisfied by reforming natural gas (methan) to hydrogen, so nower days hydrogen is a fossil fuel,
the good point, the hydrogen is not stored under preasure,
another example metalhydrid storage is used in the modern german submarine U212-A[1]
in my oppinion hydrogen is for storing energy within
a.) isolated electrical networks, (island-networks) (if energy is avaible and its not used, it´s lost, than you can live with 25% efficiency )
b.) on space stations ( less weight and less space is used in contrast to batteries )
c.) military submarines ( safety, heat, silent )
except when nuclear fusion is working, than making hydrogen by hydrolysis might by viable.
[1] http://de.wikipedia.org/wiki/U-Boot-Klasse_212_A
But it's not one of the major hurdles that needs to be overcome to use hydrocarbons. Regarding the "hydrogen economy," Hydrogen is actually pretty far from ideal as a storage mechanism. Liquid hydrocarbons turns out to be one of the best ways to store hydrogen all around, and the infrastructure's already in place to handle it.
The way to get off "foreign oil" is to produce synthetic octane/diesel fuel. Since it's already possible to do this in a number of ways, the thing holding us back from kicking the oil habit is that oil is freakin' cheap. It's already made, all you have to do is pump it out of the ground. And maybe a little fractional distillation, but that's peanuts compared to the energy needed to synthesize liquid hydrocarbon fuel (or any easily transportable fuel, really.)
We'd all better hope that the carbon trapped in easy-to-get spots is pretty much insignificant atmosphere-wise, 'cause the cat's out of the bag, and it's not going to stop being pumped till it's gone.
Can you be Even More Awesome?!
To implement this system, you'd have to:
(1) Procure a LOT of aluminum.
(2) Extract hydrogen from water.
(3) Bottle and ship the hydrogen.
(4) Burn the hydrogen in car engines.
(5) Ship the aluminum oxide to the extraction plant.
(6) Dissociate the aluminum oxide.
(7) Go to step 2.
For the pre-"breakthrough" concept, just skip steps 1, 5 and 6.
rj
Yes, making aluminum from aluminum oxide takes huge amounts of energy. And... making aluminum oxide out of aluminum *RELEASES* huge amounts of energy. This makes it perfect as an energy *STORAGE* medium. Thanks for pointing out that conservation of energy still exists.
Actually 9 out of 10 cars GMC sells gets better than 30mpg. Also, what is the average gas milage of Mercedes or BMW? You seem to have some bigotry towards America.
You have to recycle the aluminum oxide back into aluminum. This is probably quite similar to the way you get teh aluminum out of the ore in the first place. This process is, however, rather expensive in terms of energy. So this is not really a way of generating energy as much as it is a way of transporting energy.
There are some really good up sides to this. You need electricity to seperate aluminum oxide into metallic aluminum. But you can generate electricty with nuclear, hydroelectric, solar, wind, etc. The list goes on. But you cannot easily put a nuclear reactor or enough solar panels or a workable wind generator or any sort of hydroelectric plant into a automobile. So it is useful for moving energry.
It is also useful because you can use "secondary use" aluminum as fuel. Crack the aluminum out of the ore. Make cans out of it. Use the cans. Recycle the cans and use them as fuel, reclaiming the energy put into the making of the can as fuel. This is where the "free" energy comes from. Reclaiming energy that was previously wasted. Not exactly "free", but certainly "unused" right now.
But the gallium isn't consumed. You can reuse it over and over.
*sigh* back to work...
I don't know what the hell the GP was talking about, but he did somehow manage to come close to the practical overall efficiency (roughly 20-35%) to convert a given fuel to electricity, and to convert that electrical energy to hydrogen through electrolysis. Sure, the electrolysis part of the equation can be pretty damned efficient, though.
The thing that bothers me most about the article is that they don't mention how efficient the entire system is. They pretend that recycling the aluminum oxides is simply like melting scrap aluminum down, and turning it into something else. Electrolyzing aluminum oxides is a high energy process, and I can't imagine that it's very efficient at all, from an energy system standpoint.
What I would like to see is a technology that synthesizes fuel oil by taking water, atmospheric carbon dioxide, and electricity and putting out something roughly comparable to diesel fuel, kerosene, or something else.
Constitutional rights may be respected, repealed, or modified; but they must never be ignored.
Incorrect. Extracting Aluminum from Al2O3 takes a LOT of heat - ie: energy. You're, essentially, calling for the use of even more energy than you extract from the resulting hydrogen.
Hint: Water is a component of all hydrocarbon ash. You can't extract energy from it. You can only dump energy into it to make it hydrogen, and re-extract it.
In terser words: A hydrogen economy is a waste of time, far as I've seen. That is, I havent seen any process for the mass production and transport of hydrogen that gets better efficiency than your standard ICE.
Alternatives: raw solar (too inefficient at the time of this posting), ethanol (via DEFC, *not* ICE; still not fully developed), thorium nuclear (some engineering problems to be overcome, but most promising), thermal conversion (more a waste management solution than an energy-infrastructure solution).
I'm looking forward to thorium fission. I'm not looking forward to a hydrogen economy.
110100 1101000 1101000 1100110 0 1101111 1101000 1100011 1
Nice idea, but aluminium smelting isn't something that can be just turned on and off on a daily basis as the cheap power becomes available.
Actually, once the reaction takes place you have Alumina, i.e. Aluminum Oxide. Although you could say this item is "recyclable" it's actually quite worthless to do so. It takes an incredible amount of energy to convert it back to aluminum, not to mention the process of creating aluminum from alumina oxide requires the reaction of a carbon anode which generates carbon dioxide. Also, the electrolysis has to occur at high temperatures which are probably generated with coal. My guess it would be far more efficient to just continue using the alumina that is efficiently mined and transported in bulk than to try recycling the byproduct from each vehicle. The gallium might be much rarer, I don't know.
So, pure hydrogen on the other hand can be generated by a simple science experiment. Just try making your own aluminum at home and see how easy it is.
Don't compare this to recycling of cans.
Melting Aluminium (from cans) is not so hard (relatively speaking).
Changing Aluminium Oxides (like alumina from bauxite or alumina left over from this Hydrogen process) into Aluminium is hard.
Just to add some information, the reference to how much waste a 1000MW nuclear plant produces is wrong. With reprocessing, most of the 33t of "waste" is reusable.
e ssing
:) the sarcophagus of the reactor! With this surprisingly great news, maybe the only way to save the Amazon is to dump nuclear waste all over it - sad but true.
http://en.wikipedia.org/wiki/Nuclear_power#Reproc
So assuming just 90% is reused, that results in about 3.3t of actual waste. 3.3t at that densities is less than 0.5 cubic meter. That's one barrel of waste for 1000MW or 1GW power plant per year. And without reprocessing there is enough Uranium and Thorium for few hundred years. With reprocessing, there is enough for a thousand years or more. But then I'm sure we'll be able to come up with Shingle Solar Panels on every roof and fusion so no problem.
PS. For the radiation worried crowd - the Chernobyl disaster actually *saved* the environment around that town. The no-go zone is now one of the best animal and bird sanctuaries in Ukraine and surrounding regions. Endangered birds are now gaining in numbers even having their nests *inside* (well, on the building, not where the core is
Name one situation, ANYWHERE, that you get more energy out, than was put in. That would be called PERPETUAL MOTION or perhaps COLD FUSION.
The fact that hydrogen doesn't violates all known laws of the universe is a good thing, IMHO.
No, it certainly isn't.
Gasoline is currently cheaper, no question, but it's going up all the time, and the idea is that developing better and newer methods of hydrogen production will lower prices.
Internal combustion sure as hell isn't anywhere near as efficient as a hydrogen fuel cell.
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