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.'"

The Beauty Of Closed Systems

[bc90021]

This is a significant breakthrough, not because it enables the hydrogen economy (which is important), but because it makes it a more closed system. In their scenario, the aluminum and gallium are recyclable and more importantly *reusable*. It means that filling stations could exchange your car's waste products for recycled waste products from your neighbour's car. Granted, this has costs. Right now, the costs seem to be the prohibitive factor, but hopefully adoption of the technology will lower them, as it does with most new technologies.

Re:The Beauty Of Closed Systems

[tajmorton]

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 [eetimes.com].

Re:

[Harmonious Botch]

It requires 1 lb of recycleable aluminum per mile. GP is right; it is a closed system.

Re:

[Bill_the_Engineer]

It requires 1 lb of recycleable aluminum per mile. GP is right; it is a closed system.

Well it will take additional energy to recycle aluminum, so how is this a closed system?

Here is an interesting quote (from http://www.eia.doe.gov/emeu/mecs/iab/aluminum/page 2.html [doe.gov]):

According to the most recent Manufacturing Energy Consumption Survey (MECS), the U.S. aluminum industry consumed about 727 trillion Btu of energy in 1994 (including electricity losses). This amount represents slightly less than 1% of domesti

Re:

[Forge]

It's not a closed system. It requires the input of kilowatts of electricity. Megawatts for any kind of large scale production.

However it dose solve the biggest problem with a Hydrogen economy. We have existing networks for transporting Water, Electricity, Natural Gas, and Gasoline. Hydrogen is more volatile than any of those items and requeiers new transport network to get it from the point of production to the filling stations.

If you are just transporting water and electricity to the filling station whic

Re:The Beauty Of Closed Systems

[Doppler00]

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.

Re:

[Plutonite]

One pound per mile of aluminium that, unless you have a really long cable, you have to carry with you.

What's this about a cable? Can you request the aluminium in bytes? In either case, I think you're talking about TUBES.

Re:

[Fordiman]

Dunno. Do you have some elitism about being environmentally conscious?

My hybrid gets about 60MPG in practical conditions. That's about 7 miles per pound of gasoline.

By the way, even your haughtily most efficient car only gets about 30% of the energy out of its petrol. Carnot is much, much holier than thou.

Re:The Beauty Of Closed Systems

[Beardo the Bearded]

My bicycle gets more.

Aluminium takes masses of energy to "mine"

[Joce640k]

Aluminium is extracted via electrolysis and takes masses of electricity to produce. Hope you're adding this energy into your "zero sum".

Re:

[bc90021]

The article talks of local power plants that could be used to provide electricity without it having to be distributed on the grid, effectively closing the system and making it substantially more efficient. Efficiency with the aluminum should come as the technology matures.

Re:

[WrongSizeGlass]

Also, it's still not terribly efficient, since it requires 1 lb of aluminum per mile you drive.

So if I was made of aluminum I could drive 200 miles ... and Rosie O'Donnell could drive even further!

Seriously, since aluminum is light 200 lbs would probably take up too much space in a compact, no? And I realize that 200 miles isn't that far, but since I already spilled the beans on my weight I figured I'd stick with the number ;-) The process to replace/recycle the aluminum & gallium better be quick and easy or we'll spend more time as the "gas station" recycling than we did waiting for gas.

Re:

[burni]

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 oppinio

Re:

[Rei]

If you think electrolysis has an efficiency of 50%, you're off in la-la land. Electrolysis is very efficient. Now, if your electricity comes from any sort of heat cycle, you have the heat cycle losses, but the conversion from electricity to hydrogen isn't bad.

What I want to know about this tech is *its* efficiency. Given one pound of aluminium per mile, I'm betting "very low". Anyone care to run the numbers?

Re, density: Aluminum is notably denser than gasoline. Off the top of my head, I seem to recall

Re:

[Dun Malg]

If you think electrolysis has an efficiency of 50%, you're off in la-la land. Electrolysis is very efficient. Now, if your electricity comes from any sort of heat cycle, you have the heat cycle losses, but the conversion from electricity to hydrogen isn't bad.

If you're talking about the amount of energy you get out of a given volume of hydrogen via combustion vs. the amount of energy you put in to crack that hydrogen from water, you're looking at a 50-70% efficiency range. He may be pessimistic at 50%, but he's certainly not "in la-la land".

Re:The Beauty Of Closed Systems

[Deadstick]

Closed system, BFD. The classic hydrogen concept -- electrolyze water, bottle the H2, burn it in an engine -- doesn't care if it's open-cycle because water is fungible.

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

Re:

[Phase Shifter]

For the pre-"breakthrough" concept, just skip steps 1, 5 and 6.

Better, skip steps 2-4 and use the aluminum as an anode in a galvanic cell, skipping the obligatory loss of efficiency from having pointless extra steps in the process.

Re:The Beauty Of Closed Systems

[Rei]

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.

Re:

[Rei]

Er, that should be "Refining aluminum oxide is an incredibly energy-intensive process". :)

Re:The Beauty Of Closed Systems

[Fordiman]

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.

How do you get the hydrogen back out?

[Spazntwich]

Is this reusable? I was under the impression that once particles are oxidized, they're fairly difficult to separate. Seems like there might be some weird energy investment issues.

Re:

[kmac06]

The hydrogen is burned and released into the atmosphere as water. Since you get water from the environment for this in the first place, that's not the problem. The problem is getting the aluminum back, which, if you RTFA, you would have seen can be done with "fused salt electrolysis".

Alumina to Aluminum = huge energy and pollution

[Albinoman]

Wikipedia has an article on the Hall-Héroult process [wikipedia.org], 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.

Re:

[Spazntwich]

Yeah, that was my whole point in my post, but... I kind of borked the whole thing beyond salvage.

Slashdot needs a delete button for retards like me.

Re:

[MichaelKaiserProScri]

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,

Re:

[glittalogik]

Free as in leftover beer from the night before - doesn't taste as good, but it'll get you where you need to go =)

Re:

[Dan Ost]

It takes electricity to recycle the aluminum oxide, but you can supply that electricity with clean sources (solar, wind, etc). Even if you only use power from the grid, you'd do it at night when the power is cheapest which would bring the base-load power generation closer to the peak always a good thing since peak power is typically generated using the least efficient means we've got (oil and natural gas power plants).

An increase in the base-load would allow more efficient plants to be constructed. This red

Re:

[InvalidError]

There was a similar technology using magnesium or some other metal a few months ago.

The catch with all these little alternative is that most promoters conveniently leave out the details of how much power and other costs are involved in manufacturing and recycling the spent metals when addressing the general public in promotional material.

When auto manufacturers and reviewers praise the fuel-efficiency of hybrids, they conveniently leave out the fact that the battery pack needs replacement every few years. C

Still ONLY an energy STORAGE medium.

[Archeopteryx]

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.

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[contrapunctus]

Exactly. Making aluminum is energy intensive. Where does that energy come from?

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[Gerzel]

Historically Niagara Falls, Nuke plants, other hydro plants and coal.

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[contrapunctus]

The question was rhetorical. Coal is probably the biggest in the US. My point was that it's most likely a fossil fuel of some sort (excepting Iceland with their geothermal resources).

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[Anonymous Coward]

From Hydrogen. Duh. They just found an easy way to make it - using Aluminum.

Re:Still ONLY an energy STORAGE medium.

[kmac06]

Yes we do. Nuclear energy is cheap, clean, and plentiful.

Re:

[FooBarWidget]

It is? I keep hearing that our uranium sources will only last for 50 years unless we seriously modernize our plants (so that they can process nuclear waste products as well).

Re:Still ONLY an energy STORAGE medium.

[wierdling]

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.

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[vonhammer]

Not even close to true. Uranium is very plentiful. In fact, if necessary, it can be extracted from sea water. The cost of the fuel is negligable compared to the cost of handling/disposing/etc.

Re:Still ONLY an energy STORAGE medium.

[Prune]

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.

Re:

[mpe]

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.

There's also decommisioned nuclear weapons which could potentially be used as fuel.

Re:Still ONLY an energy STORAGE medium.

[Usquebaugh]

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.

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[WrongSizeGlass]

Yes we do. Nuclear energy is cheap, clean, and plentiful.

Mr. Burns? Is that you??

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[Scrameustache]

Yes we do. Nuclear energy is cheap, clean, and plentiful.

It 'burns' fuel and produces waste: It is not clean.

It is very clean relative to our current sources

[Solandri]

According to anti-nuclear activists [nonuclear.net], a 1000 Megawatt nuclear plant produces 33 tons of waste per year.

According to the Union of Concerned Scientists, [ucsusa.org] 1000 Megawatt coal plant produces 250,000 tons of ash and 486,000 tons of sludge in a year.

So on a strictly weight-for-weight basis, nuclear is over 22,300 times cleaner than coal per megawatt. The nuclear waste is also highly regulated with stringent disposal requirements (if our politicians will get off their duffs and decide on a place to put it). A large portion of the ash and sludge from a coal plant is simply disposed into the atmosphere or sent to landfills where it ends up in our lungs and our water.

Yes, yes, everyone wants near-zero emission renewable energy. But given that that is currently not cost-effective enough to compete with coal, nuclear is a tremendously cleaner stepping stone that's available here and now, while we do the R&D to get the renewable costs down to where they're competitive.

Re:It is very clean relative to our current source

[gnuman99]

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.

http://en.wikipedia.org/wiki/Nuclear_power#Reproce ssing [wikipedia.org]

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 :) 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.

Re:

[Jessta]

Nuclear power produces waste that needs to be stored for thousands of years in secure facilities, thousands of years of storage is expensive.
To make sure these facilities continue to function we need a stable government for that whole time.

Think about it, the egyptains made the pyramids only a few thousand years ago and was hardly any information about them when we found them. Imagine if they were nuclear waste storage.

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[Angostura]

... the CO2 we are producing is likely to be around even longer. The nice thing about nuclear waste is that people actually appreciated that it is dangerous.

Re:Still ONLY an energy STORAGE medium.

[Dan Ost]

In a hundred years, we'll have processed all that "waste" into fuel for modern reactors.

We have the technology now that we could, if politics didn't interfere, build reactors that fed their "waste" into secondary reactors who fed their "waste" into tertiary reactors. The resulting "waste" would be close enough to the background radiation that disposal is a non-issue (dare I say that we'd use it to make glow-in-the-dark watch hands and night sights for handguns?).

The nuclear issue is almost purely political at this point. Nuclear waste even more so.

Re:Still ONLY an energy STORAGE (nukes??? not)

[Ralph Spoilsport]

kmac06, aka clueless troll, wrote:

Yes we do. Nuclear energy is cheap, clean, and plentiful.

Yes, and based on another limited and expensive resource about to peak and go into depletion: Uranium.

And if you bark about "breeder reactors make their own fuel", then you're ignoring the relationship between the necessity of universality in sustainable development and political realities. That equation is fulfilled with North Korea, Afghanistan, Iran, and any number of smaller and unstable regimes scattered ar

Re:

[--daz--]

I couldn't locate concrete numbers, but I'm willing to bet we spend a LOT more money funding Global Warming fear mongerin-- I mean research than we do Fusion power generation research.

It seems like we're just wasting good research dollars at explaining just how evil humans are rather than solving whatever problems we created (real or imagined).

Re:

[DarkOx]

The trouble is when will rocketry be safe enough.

When you consider the potential catastophe that even one acident could cause it will almost never be safe enough. The debris from the last suttle accident was spread accross multiple states!

I used to be very anti-nuclear simply because dispite the excelent safety record the damage as a result form an acident has the potential to be so incredible. That said there have only been two major incidents with nuclear electrical plants. TMI was basically a non-issu

It's all about flexible energy source CHOICES.

[Mateorabi]

Except that storage is one of the major hurdles that needs to be over come to use hydrogen.

With this, the car's power source has been decoupled from our choice of power supply. We can use what ever source for energy to turn the 2Al2O3 back into 4Al + 3O2. Today we can use coal burning plants for the electricity, tomorrow nuclear, the next day solar and wind, the next fusion. You don't need to upgrade your car every time we invent (and/or make economical) a cleaner power source.

Re:It's all about flexible energy source CHOICES.

[zippthorne]

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.

Re:

[c_fel]

But still, it's a great solution for the inefficiency of our cars actually. From the article : the efficiency of a hydrogen-powered vehicle is around 70%, compared to 25% with our actual gasoline system.

Maybe it's not the "solution for all problems (tm)" but in my opinion it's very interesting. I'm eager to hear more on these researches.

Re:

[vertinox]

So? All matter in the universe is energy storage including ground based petroleum and bio-fuels. These energy resources don't just spontaneously come into being.

Hydrogen efficient in releasing energy, but rather difficult to use energy to produce it.

Consider that aluminum used to worth more than gold back in the 1800's. Now we can go to the grocery stores and buy a six pack of drinks with cans made of this stuff.

Give it time and the production might be even more efficient.

Re:

[Bloke down the pub]

Hydrogen efficient in releasing energy, but rather difficult to use energy to produce it.

There's nothing difficult about producing it. Storing it's the problem. Them little molecules can get where rats, roaches and water can't.

Re:

[Old Benjamin]

Nuclear power anyone? It's cheap. It releases less radiation than coal fired plants (coal contains uranium). It's not something where we would be dependent on the middle east (a lot of uranium comes from Canada).

In response to talk about nuclear waste, I say that 1: bury it, and 2: Hopefully, in a few years fusion will be usable, if not perfected, and even cheaper, and safer because it uses hydrogen isotopes, to create things that aren't radioactive.

Re:

[Scrameustache]

We need to have a source of reliable cheap electricity to make the aluminum. And we don't at this time.

What?!?

Hydroelectricity [aluinfo.de], a renewable resource, is the most important source of energy for producing primary aluminium. About 60 per cent of the world's primary aluminium is already being produced with the help of hydroelectric power.

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[Spy Hunter]

You say that as if an energy storage medium with size, weight, and durability, and power to match the gasoline engine wasn't a major breakthrough that could have enormous benefits for society. In fact, energy storage and transport is just as important as generation, but has seen a lot less practical advancement in the last 50 years.

As a society we desperately need improvements to energy storage. Better storage means we can use more efficient and cleaner means of generation. We will probably never have fi

Re:

[ebbomega]

Alcan Aluminium works out of British Columbia, and is one of Canada's major Aluminium manufacturers. BC's electricity is provided via hydroelectric dams - very common amongst the west coast of Canada. I don't see why this cannot be a cheap, reliable and reusable source of energy for it.

Or...

[evanbd]

You could add sodium hydroxide (lye) or another base to the water, to dissolve the oxide layer. Their solution is probably safer, but mine you can buy at the drug store. And fill balloons with the H2. (Oblig warning: NaOH is nasty caustic, and H2 is ridiculously flammable with a *huge* explosive range in air. Don't do this without appropriate safety precautions.)

What I'm actually curious about is why they think this is useful. The energy released only partly goes into cracking the water; an awful lot of it comes out as heat, which is both wasteful and has to be removed from the system. And all that energy came from electricity to refine the aluminum from aluminum oxide ore. It seems to me you should just ship the electricity in the normal manner and use it to charge conventional batteries, which have really gotten rather efficient lately.

Re:

[kmac06]

According to the article, the energy that can be extracted from the hydrogen is about the same as the energy that is released as heat, so it's still 50% efficient. And some of that heat can probably be recovered, though that would take a lot of extra hardware in the engine to do so. Also according to the article, this has an energy density about 2.5 times less per pound than gasoline, and about the same density per volume. I don't think batteries can match that yet.

Re:

[evanbd]

an energy density about 2.5 times less per pound than gasoline, and about the same density per volume

Yes, but what's the energy per dollar look like? I'm guessing it's poor in comparison to gasoline and especially electricity, seeing as aluminum is rather expensive -- $2-3/lb in medium quantities, before you count the gallium.

Re:Or...

[evanbd]

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.

well there will also be the hybrid version ....

[taniwha]

which also includes a steam engine ....

Re:

[Anpheus]

And supercapacitor technology (while another one of those techs that seems perpetually on the brink of being workable & cost effective) is always improving. A lot of people, namely conservatives, like to tout that having electric cars merely displaces the pollution generation to the coal and natural gas plants that provide most of the world's electricity; conveniently ignoring that even some of the oldest and most inefficient coal generators are more carbon friendly than the average car or truck.

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[evanbd]

Supercaps are definitely worth watching. Commercially available (though pricey), they're about 1/10 the energy density of lead-acid batteries these days. They seem to run about $15/kJ for high density, high discharge rate caps. You can get 400F, 2.7V in a package the size of a D cell battery for $30 qty 1, much less in bulk. I give it 3 years till they're competitive with batteries for energy density, and another 3-5 after that till the prices look reasonable.

Why Water?

[sanman2]

Hmm, so you're using aluminum to turn water momentarily into hydrogen, only to turn it back into water moments later through combustion?
What did you need the hydrogen for then? Why don't you just extract the energy directly from the aluminum in one conversion step instead of 2? The more conversion steps you have, the more losses. The fewer conversion steps, the better.

Re:

[evanbd]

Mostly because it's really hard to get aluminum to burn in air, so you need something to react it with. Water gives you hydrogen, which is easy to work with. Of course, this whole idea seems rather hopelessly inefficient and expensive.

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[ChrisMaple]

Save a step. Add metallic sodium (or potassium) to water; it generates hydrogen and plenty of heat - explosively. Cheap, lots of danger and toxic byproducts. What more could you possibly ask for?

Gallium too expensive for this.

[Animats]

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.

Re:Gallium too expensive for this.

[qbwiz]

Consider that the price of platinum (as used in catalytic converters) is around $1350/pound ($2976/kg), and the price of palladium (used for the same purpose) is around $355/pound ($780/kg). Depending on how much gallium they really need, this really could amount to exchanging trace amounts of one expensive element for trace amounts of another expensive element.

Also, note that they say in the article that they would only need low-purity gallium, which would have a lower price (although the price would also be raised by the raised demand, granted).

Re:

[rolfwind]

Platinum is $1326 current PER OUNCE. Pallidium is $361 PER OUNCE.

If you want the per pound price, multiply by 16.

Re:

[reverseengineer]

Actually, that's the price for a troy ounce, which still holds on as the customary unit for precious metals. There are 12 ounces troy in a troy pound (which is the same pound as in the currency pound sterling- it was originally defined as one troy pound of sterling silver) . For reference, a troy ounce is about 31 grams while an avoirdupois ounce (the 1/16 of a lb. ounce) is about 28 grams.

Ah,

[rolfwind]

My mistake and the stupidity of SI.

I wish everybody moved to metric.

Re:

[pavera]

Platinum is also used in fuel cells, so I doubt you could drop that cost, just move it from the cat converter to the fuel cell.

In the best case, we would be using the hydrogen produced in this reaction in an efficient fuel cell which would allow for much higher efficiency than hydrogen combustion. The article mentiones 75% efficiency for the fuel cell vs 25% efficiency for the combustion. I don't know if palladium is used in fuel cells, but I do know that the cost of Platinum is one of the major factors i

Re:

[kmac06]

According to the article, most gallium that is sold is high purity, which may be part of the reason for the high price, and for this application, low grade gallium would work. Even if it is that expensive, it's a one-time investment. The gallium doesn't get used up in the reaction.

Re:

[cheater512]

The thing is that the gallium isnt used in the process. Its comes out as a by-product which can be recycled.

Re:

[pavera]

wrong. The pellets are an aluminum gallium alloy. yes, you can recycle the pellets and reuse them, but going from 0 gallium in our gas tanks to even 5-10KG (they are talking about 350lbs of the alloy in a tank, I think its safe to assume at least 10-20lbs of that is gallium), well at $500/KG, that is 2500-5000 added to the cost of every car.

Re:Gallium too expensive for this.

[Dan Ost]

But the gallium isn't consumed. You can reuse it over and over.

Not quite a revolution . . .

[Caffeinate]

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.

Once again ignoring the energy needed for aluminum

[plasmacutter]

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.

Re:Once again ignoring the energy needed for alumi

[markom]

While it is true that Aluminium smelting uses up a lot of energy, the rest of the process is remarkably pollution-free (most of the catalysts are recycled and reused in smelters). As for the energy, there are places in the world that produce vast amounts of clean energy that is used for aluminium smelter. One example of this is Iceland (where I live).

electricity still needed to process the aluminum

[HighOrbit]

FTFA:

However, the cost of aluminum could be reduced by recycling it from the alumina using a process called fused salt electrolysis. The aluminum could be produced at competitive prices if the recycling process were carried out with electricity generated by a nuclear power plant or windmills. Because the electricity would not need to be distributed on the power grid, it would be less costly than power produced by plants connected to the grid, and the generators could be located in remote locations, which would be particularly important for a nuclear reactor to ease political and social concerns, Woodall said.

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.

Aluminium = Energy Hog.

[Ihlosi]

For anyone who didn't know that yet:

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

YES - We have to get O2 out.

[oni]

In addition to what you said, I just want to point out that any idea to crack H2O that doesn't release O2 is bad. The article mentions a way to get H2 out of H2O, but the O2 gets locked up in the aluminum. So that means, if you drive around in your Hydrogen car, it is sucking from the atmosphere O2 **that you didn't put there**

Let me say that again: Your Hydrogen car would be sucking O2 out of the atmosphere. If everybody did this, then our global climate change problem would no longer be adding CO2, it

Re:

[evanbd]

Well, you can improve that reaction by running it at high temperatures -- around 800C, say. At that temperature, a significant fraction of the energy needed to crack the water comes from the heat. That is, in a normal (room temp) electrolysis cell, even if there are no resistive losses, some of the electricity is turned into heat. At high temp, with low or no resistive losses, you have to *add* heat to maintain a steady state, which can be the waste heat from your electric plant.

That said, it's not tri

Why not go direct to the source?

[tgatliff]

Call me a optimist, but instead of developing indirect ways to make energy, why dont we just focus all of our attention on developing non-toxic and high energy density batteries. We do have nuclear power plants after all which are not only zero emissions, but also can provide energy worldwide. Personally, if we can put a man on the moon and bring him back safely in under a decade during the 1960's, I think we can probably develop a battery that we can use in your cars of the future....

How do you do this??

Pardon me while I roll my eyes

[Stickerboy]

"With aluminum at $1.25 a pound, all it needs would be a large check from the government and someone to build as many nuclear or solar/wind power plants as it takes, and we could make this competitive with $3/gallon gasoline!"

Really... and while we're replacing 131 billion gallons of gasoline a year with aluminum pellets, will aluminum still be $1.25 a pound?

Write back when you get the funding for all of those nuclear plants for the sole purpose to recycle the pellets...

Re:

[Shados]

Yeah, that always seem to be the missing link in the equation. Its a bit like ethanol... As soon as it started becoming more mainstream, corn and such skyrocketed. Useful! ::cough::

Electrical Engineering prof? Riiiggght.

[Excelcia]

The reaction was discovered by Jerry Woodall, center, a distinguished professor of electrical and computer engineering.

Ya, sure it was.

Charles Allen, holding test tube, and Jeffrey Ziebarth, both doctoral students in the School of Electrical and Computer Engineering, are working with Woodall to perfect the process.

They had nothing to do with discovering it... nope... because, they're just students, and students can't never discover nothin'.

The above is why I could never do post-graduate work. I'd love to do research - but the idea of having my discoveries and/or inventions stolen by some ossified... err.. tenured relic because that's just the way the system works just makes me angry.

Insanity I tell ya!

[iminplaya]

All these nutty attempts to build and maintain a whole new infrastructure with dangerous, poisonous, chemicals and just as dangerous high pressure wessels, and biodiesel produced from algae(as opposed to the stupidity of using corn and sugar), using what we already have to refine and transport it, never even gets an honorable mention. We could be using the stuff right now if it wasn't for our infatuation with pop science from "beyond 2000" distracting us from putting a very workable system into place with m

Up to 0.11 kg H2/kg

[Michael Woodhams]

The basic reaction is:
2Al + 3 H20 -> Al2O3 + 3 H2

Aluminium has an atomic mass of about 27, so 54g of Al will produce 6g of H2, i.e. it takes 9kg of Al to produce 1kg of H2. (We haven't been told how much gallium is required in the mix, so I'm ignoring this component.)

According to Wikipaedea, the goal for hydrogen storage in 2015 is 0.09 kg H2/kg. This process rates at 0.11 kg H2/kg before accounting for the gallium - so it is looking pretty good so far.

I've neglected the weight of water used in the reaction. If we include this, it doubles the required mass: 54g Al + 54g H2O to produce 6g H2. We may be able to recycle the engine exhaust to provide the required water. However, this scheme means that you gain weight as you run your car: everytime you use 6g of hydrogen, you turn 54g of Al into 102g of Al2O3, which you are still carrying.

I'm also worried about the efficiency of the fuel cycle, which will require returning large amounts of Al2O3 from fuel stations to a recycling plant, which then uses electricity to convert the Al2O3 back to Al.

Big Deal

[PPH]

My car has been releasing free hydrogen for years.

Rust never sleeps.

Finally!

[myowntrueself]

Finally, built-in obsolescence for aluminium boats!

I predict that sales of antifouling paint will skyrocket when boat manufacturers get hold of this formula.

Efficiency?

[PPH]

It appears that this is nothing more than one step in a kind of 'aluminum battery'.

From TFA:

the cost of recycling aluminum oxide must be reduced

An energy input is still required for this 'fused salt electrolysis' and the question is: will the complete cycle (including the recharge) be more efficient than current electrochemical battery technology? Also, don't forget the system's weight. You've got to lug around aluminum, water and gallium. Additionally, you can't dump all the waste product out the tail

Re:

[$RANDOMLUSER]

That releases too much methane.

Re:

[Bloke down the pub]

Then don't release it, use it to power a turbine.

Re:

[h2_plus_O]

Hydrogen will never be a good replacement for gasoline.

And 640k should be enough for anyone, too.

It's unstable, highly reactive, hard to transport, and hard to produce in an efficient manner.

Gasoline had significant drawbacks as a fuel as well, that were also overcome - it's poisonous, explosive, tough to refine, and required significant technology to transport and store safely. If gasoline had to go through the same scrutiny hydrogen is being faced with today, it would never have been approved as a fuel

Re:

[ChrisMaple]

Interesting link, but the aluminum-air battery appears to be only about twice as power-dense as zinc-air, which is an established technology used primarily in hearing-aid batteries. Neither seems likely candidates as secondary cells, which is what we really want.

Re:Ah yes, Hydrogen Junk Science!

[evilviper]

Hydrogen cars are junk science. Sorry folks, but hydrogen takes MORE energy to make than you get back.

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.

And Hydrogen is energy poor.

No, it certainly isn't.

Burning gas is cheaper, cleaner and more efficent in a hummer or any SUV.

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.