Purdue’s Aluminum Boilermaker

Success in the War Against Oil requires innovation.

Jerry Woodall of Purdue University is an innovator.

He has posted a demonstration at Science Friday in which, he says, fuel hydrogen can be produced at a cost equivalent to gasoline, for use in fuel cells. He notes at the outset that fuel cell technology also must improve radically, since it is now dependent on expensive platinum, but that’s another show.

Rather than using electrolysis to produce hydrogen, Woodall used a simple chemical process. First he dissolved a little aluminum into gallium, creating an alloy. This is not hard because gallium turns from a solid to a liquid at just 30 degrees centigrade, and his molten mixture was stable at 50 centigrade. He used a hot plate to make it.

Then he poured water into it.

What happened was that the aluminum oxidized into alumina, creating both hydrogen and heat. For each 2 atoms of aluminum and 3 of water, he got three hydrogen molecules, a molecule of AlO3 (alumina) and heat. The gallium settled to the bottom of the vessel after acting as a catalyst for the reaction. The process took three days, leaving behind a white alumina powder and, below it, liquid gallium. The hydrogen was then extracted and measured.

Pretty impressive. But it gets better.

Woodall next produced an alloy of aluminum and gallium, 80% aluminum
by weight. This is a safe, inert, rock-like piece of metal. In his
demonstration, Woodall dropped a little bit of this alloy into a test
tube, then added water. In this case the reaction took place at room
temperature, again yielding hydrogen and alumina. The gallium is
completely recovered. Since he doesn’t require the kind of purity
electronics makers need from his gallium, and he recovers all of it, he says, the gallium costs are low.

Of course there are questions:

1. What’s the energy cost of creating the aluminum-gallium alloy?
2. How do you recover the aluminum from the alumina?
3. What about the water?
    

He answered the second question. It’s 9 kwh/pound of
aluminum. He recommends siting the aluminum recycling plant near the
cheapest electricity possible, say at a nuclear power plant. But any
generation source would do. (We can talk about that.) Aluminum recycling, fortunately, is a thriving industry.

As to the third question, one source of pure water would be the fuel
cell process itself, which produces water as its waste product.

What is important for our discussion is that you have a shelf-stable
process for producing large quantities of hydrogen. Gallium, aluminum,
and alumina are all safe to move around. The result is
hydrogen for transportation at a price competitive with gasoline,
$3/gallon.

Is the aluminum boilermaker an ultimate solution to the War Against
Oil? No. It’s one innovation out of many which are needed. We need
better fuel cells, created with materials other than platinum. We need
to move this hydrogen around — it’s not shelf stable. (Remember from
previous episodes that hydrogen could conceivably be turned into
ammonia, which is a liquid at room temperature.)

But this kind of thing, multiplied many times around the world, is how the war will be won.

Postscript: In an interview with MSNBC Woodall hinted darkly that there may be some conspiracy in the Department of Energy that prevents him from getting funding. Woodall, who also heads the school’s entrepreneurship program, should know better. The charge makes him sound like a crank, and the real reason he’s having trouble getting funding is something he mentions himself, the high cost of current fuel cell technology. Woodall has proven he can meet demand for hydrogen. Now we need better fuel cells to stimulate his supply.