Hydrogen Storage for Cars?
December 21, 2007Hydrogen is the fuel of the future. Unfortunately, one problem remains: Hydrogen is a gas and cannot easily be pumped into a tank like gasoline. Storage in the form of solid hydrides, chemical compounds of hydrogen and a metal or semimetal, are good storage materials in principle, but have not been well suited to automotive applications.
An American research team at the Ford Motor Company in Dearborn and the University of California, Los Angeles, has now developed a novel hydride that could be a useful starting point for the development of future automotive hydrogen-storage materials.
As Jun Yang and his team report in the journal Angewandte Chemie, an “autocatalytic” reaction mechanism causes the composite made of three different hydrides to rapidly release hydrogen at lower temperatures and without dangerous by-products.
Certain hydrogen compounds, such as lithium borohydride (LiBH4 ) and magnesium hydride (MgH2), can release hydrogen and then take it up again. However, for automotive applications, they require temperatures that are too high to release hydrogen, the hydrogen release and uptake are far too slow, and decomposition reactions release undesirable by-products such as ammonia.
In addition, these compounds can only be “recharged” under very high pressure and temperature conditions. The combination of two different hydrides (binary hydride) has previously been shown to improve things, as these compounds partly release hydrogen at lower temperatures than either of the individual components.
The researchers led by Yang went a step further and combined three hydrogen-containing compounds—lithium amide (LiNH2), lithium borohydride, and magnesium hydride—in a 2:1:1 ratio to form a ternary hydride. This trio has substantially better properties than previous binary materials.
The reason for this improvement is a complex sequence of reactions between the various components. The first reactions begin as soon as the starting components are ground together. Heating starts off more reactions, releasing the hydrogen. The mixture is “autocatalytic”, which means that one of the reactions produces the product cores for the following reaction, which speeds up the entire reaction sequence.
The result is a lower desorption temperature; the release of hydrogen begins at 150 °C.
In addition the hydrogen is very pure because neither ammonia nor any other volatile decomposition products are formed. Recharging the ternary hydride with hydrogen can be accomplished under moderate conditions.
Citation: Jun Yang, A Self-Catalyzing Hydrogen Storage Material, Angewandte Chemie International Edition, doi: 10.1002/anie.200703756
Source: Angewandte Chemie
Sep 01, 2009 |
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Future is Solar Power stations in deserts, DC power grids, high pressure hot water storage for power storage, Solar Panels on rooves and every electric car pluged into the grid will be a backup power device. No more middle eastern oil needed.
I think battery and hybrid people are really misguided. First of all, a battery is inherently wasteful -- it weights the same whether it's empty or full. A hybrid carries around two motors.
Hydrogen is the lightest weight fuel per joule of energy released. A tank weighs less proportionally as it empties (unlike a battery).
A hydrogen car only has one, very efficient motor powered by a fuel cell -- no moving parts like a generator.
Hydrogen is the way to go by far...
My guess is that we'll crack this problem with the next generation of supercomputers which will allow us to "try" billions of combinations of potential catalysts and configurations until one is found which is cheap and easy to produce en masse and makes the water split just by being poured over it. (Then we wouldn't even need the storage: just the water and the catalyst...)
http://www.scienc...3146.htm
This looks like the immediate answer to production and storage of hydrogen.
But, of course, this is too easy and would be relatively inexpensive to produce. The industry wouldn't allow us to have anything that isn't highly complex, uses exotic materials, and thus would be expensive enough to make a not insignificant fortune.
Of course, that's just my opinion; I could be wrong.
We already have a real crisis in the Middle East. But, as usual, our solution is to go to war and appropriate somebody else's resources rather than develop a viable alternative of our own.
Of course, that's just my opinion; I could be wrong.