A worker walks between stacks of high purity aluminum ingots at the RUSAL aluminum smelter in the Siberian city of Krasnoyarsk April 4, 2007. Pellets made out of aluminum and gallium can produce pure hydrogen when water is poured on them, offering a possible alternative to gasoline-powered engines, U.S. scientists say. (Ilya Naymushin/Reuters)
Pro
It’s about time we wean ourselves off of aluminum. We must seek alternatives.
Gallium is $1000 a pound.
And in the UK,
will it be AlYuminium?
This process releases hydrogen gas. You can't drive far on a gallon of hydrogen gas. If they are talking about the equivalent of a gallon of liquid hydrogen, that's a different story. The author needs to clarify (as usual).
Hydrogen is a pipe dream. Hydrocarbons are hundreds of times more efficient. There will be one exception. There are a few technologies in the pipe that will allow us to passively store cryogenic liquids with no boil-off. That will change the outlook quite a bit.
I will say that gallium-aluminium catalyzed water decomposition is a rather interesting technology. Without Google or Wiki I imagine that the reactions would be something like:
6H2O + 2Ga + 2Al -> 6H2 + Ga2O3 + Al2O3
Problem will be when you want to regenerate the catalyst. It would be much better to find a catalyst for this reaction that you can regenerate in situ. That would be nice. Good luck.
I imagine that this would be better served at a fuel station. Pump water into a holding tank with gallium-aluminium pellets, generate hydrogen gas and then compress it to liquid form. Deliver the liquid directly to the customer, who then stores it just like gasoline. The passive insulation technologies I mentioned earlier will allow that to happen.
I still say that hydrogen is not the answer. We will be on electric vehicles before there is a “hydrogen economy.” And even then, combustion engines will be around for a long time. Things such as airplanes, power plants, they all use combustion engines. You can eliminate that by using Nuclear power. But then you still have airplanes, and I imagine unless we have some breakthrough technology, they will be running on hydrocarbons for a long time to come.
If you want to run your car on aluminum, why not do it with a mechanically recargable battery. You would get nearly 100% of the electrical energy stored in the metal. PEM fuel cells are less than 50% efficient and you would lose even more energy in the chemical process to release hydrogen. You also would have much less complexity and expense.
There have been mechanically recargable marine batteries for about 40 years.
People are just grabbing at straws trying to figure out how to make a hydrogen car.
And Gallium is a toxic substance, if I remember correctly.
How does the car perform in winter when the water in the tank is frozen?
Also, would you have to manufacture expansion joints in the tank to allow for the ice to expand and prevent the fuel tank from rupturing?
What about the other costs?* It appears that they haven’t factored in the costs of taxes, and transporting, and retailing the hydrogen fuel. If they can get the cost per mile driven to match that of gasoline — then this could be one more useful alternative.
(*Assuming that they meant that the hydrogen would have the energy equivalent of a gallon of gas.)
“Hydrogen is seen as the ultimate in clean fuels, especially for powering cars, because it emits only water when burned.”
And when it burns, boy does it burn!
If you take calcium and pour water on it you get hydrogen and calcium hydroxide. I should know. In an unsupervised high school chemistry experiment I used this reaction to create a hydrogen torch. It came to an unfortunate end when a stopper popped out of a flask and sprayed me with said calcium hydroxide.
Why not calcium since it doesn’t require gallium?
But besides the cost of making these pellets, how much energy from other sources is required to make them? Is there a net gain in energy or a loss?