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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.'"
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.
libertarianswag.com
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.
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.
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.
"You saved 1968." - Ms. Valerie Pringle to the crew of Apollo 8
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?? Simple... Challenge and encourage NASA, DARPA, DOD, and all university/research centers to focusing specifically on this one goal... Put out in specifications of what it means to achieving this goal and wait to be stunned by the wonder of human ingenuity. Commit huge amounts of money to the grants for such things.... That would assume, though, that we have an administration that is willing to commit to doing this. Something that until now we are unable to do....
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.
"The quickest way to end a war is to lose it" -Orwell
It is if it's shot into the sun. It's dense enough for solar bound rockets to be an economical method of disposal, once rocketry becomes safer.
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 minimal costs and low risks to the environment, and to humans.
What?
From the article:
He's obviously a smart guy, but c'mon... holding up the revolution?
According to the Union of Concerned Scientists, 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.
Are you arguing in terms of efficiency loss? It it takes 15.7 kWh to convert alumina to aluminium, and the aluminium releases 15.6 kWh of usable energy when returning to alumina. then there's only a 0.1 kWh to laugh about.
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.
*sigh* back to work...