Daily Tomorrow-An Eco-blog about green living, health and the environment

Aluminum: The Fuel of the Future?

by admin on May 19th, 2007

Hydrogen is the ultimate clean-burning fuel, but storing it can be a problem. It may not remain so for long, however–Jerry Woodall, an engineer at Purdue University, has just discovered a way of generating hydrogen on demand using water, aluminum, and gallium. Science Daily reports:

“Most people don’t realize how energy intensive aluminum is,” Woodall said. “For every pound of aluminum you get more than two kilowatt hours of energy in the form of hydrogen combustion and more than two kilowatt hours of heat from the reaction of aluminum with water. A midsize car with a full tank of aluminum-gallium pellets, which amounts to about 350 pounds of aluminum, could take a 350-mile trip and it would cost $60, assuming the alumina is converted back to aluminum on-site at a nuclear power plant.

If that sounds like a mighty big assumption, it is. In order for aluminum-powered road trips to cost as little as gasoline-powered road trips, aluminum would have to cost about 18 cents per pound. At the present time, aluminum costs $1.20 per pound, which means that the hypothetical 350-mile trip described above would require $420 worth of aluminum. Dr. Woodall is well aware of the gap, but believes that it could be eliminated if the alumina produced by aluminum-powered engines were recycled into aluminum at power plants by way of a process called fused salt electrolysis.

One concern not brought up in the article is the issue of aluminum’s sheer weight. If the average car presently holds 15 gallons of gasoline at six pounds per gallon, that’s 90 pounds of fuel for 255 miles worth of travel. Under the ratio described in the hypothetical scenario above, a car would need to hold 255 pounds of aluminum in order to achieve the same effect. This 165-pound disparity is unlikely to pose a serious safety concern–I haven’t heard the argument made, at any rate, that a car is more dangerous to drive if you have an extra 165-pound passenger in the back seat–but unlike gasoline, which is liquid and more or less effortlessly administered by way of a pump, the aluminum would come in solid pellets. Imagine loading 255 pounds of aluminum pellets into your car every time you want to fill ‘er up, and you can see why potential issues involving labor cost, transportation, storage, and accessibility for the elderly and handicapped might start coming into play. Many of these problems can be addressed–tiny aluminum-gallium pellets could probably be administered through a pumping mechanism just as effectively as liquid fuel is today, for example–but they will have to be resolved, and resolved in an innovative way.

None of this should distract us from the central issue, which is that these problems are child’s play compared to the side effects of gasoline use–global warming, unstable prices, massive economic power in the hands of unstable regimes, and the apocalyptic dark age we’ll all be living in if we run out of the stuff. So three cheers for the aluminum-powered car–if it makes gasoline obsolete, we’ll all be living in a safer world.

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POSTED IN: Fuel & Energy