Pellets made out of aluminum and gallium can produce pure hydrogen when water is poured on them, offering a possible alternative to petrol-powered engines, US scientists have discovered.
Hydrogen is seen as the ultimate in clean fuels, especially for powering cars, because it emits only water when burned. The trouble is, so far no-one has found an efficient way to produce or store hydrogen. There are also questions about the infrastructure needed — think of a network similar to the petrol stations in your neighborhood — to transport and supply hydrogen to car owners. This development could change all that and make hydrogen both accessible and useable.
Indeed, the metal compound pellets may offer a simple way to utilize hydrogen, says Jerry Woodall, an engineering professor at Purdue University in Indiana who invented the system. Purdue are no strangers to Treehugger - they have already come up with several innovative developments across the fuel spectrum which we've reported on earlier."The hydrogen is generated on demand, so you only produce as much as you need when you need it," Woodall said in a statement. He said the hydrogen would not have to be stored or transported, taking care of two stumbling blocks to generating hydrogen.
For now, the Purdue scientists think the system could be used for smaller engines like lawn mowers and chain saws. But they think it would work for cars and trucks as well, either as a replacement for petroleum products or as a means of powering hydrogen fuel cells.
On its own, aluminum will not react with water because it forms a protective skin when exposed to oxygen. Adding gallium keeps the film from forming, allowing the aluminum to react with oxygen in the water.
This reaction splits the oxygen and hydrogen contained in water, releasing hydrogen in the process.
As with many such scientific 'discoveries', Woodall made his almost by accident.
"I was cleaning a crucible containing liquid alloys of gallium and aluminum," Woodall said. "When I added water to this alloy - talk about a discovery - there was a violent poof."
What is left over is aluminum oxide and gallium. In the engine, the byproduct of burning hydrogen is water.
"No toxic fumes are produced," Woodall says.
"When and if fuel cells become economically viable, our method would compete with gasoline at US$3 per gallon even if aluminum costs more than a dollar per pound," says Woodall.
Recycling the aluminum oxide by-product and developing a lower grade of gallium could bring down costs, making the system even more affordable, Woodall said.
The Purdue Research Foundation holds title to the primary patent, which has been filed with the US Patent and Trademark Office. An Indiana startup company, AlGalCo LLC., has received a license for the exclusive right to commercialize the process.
Source ::Purdue Research Foundation