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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.
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
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?!
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.
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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.
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