Breakthrough Material Purifies Water While Generating Electricity
10 May 2011 3:49 PM ET
At last, little chunks of aluminum everywhere can be something greater then a soda can or a baseball bat. Thanks to a special reactive alloy, some of those lucky little nuggets could solve the world’s energy crisis.
Jerry Woodall, an engineer at Purdue University, has created an aluminum alloy that reacts with water to create hydrogen and heat. He is encouraging venture capitalists to design a system that uses both — capturing the hydrogen as fuel and using the heat to pull clean water out of the air. The greatest benefit of using aluminum is its abundance.
“There is enough aluminum on the Earth’s crust to supply the whole world’s energy needs,” Woodall told InnovationNewsDaily.
To make use of this aluminum, Woodall melts it and combines it with gallium, indium and tin. In room temperature, these last three ingredients coarse through the metal as a liquid dissolving the grains of aluminum around it. In this state, water can react freely with all the material. As pellets of the alloy drop into water, they spontaneously split the water into heat and hydrogen. The hydrogen can then be used to power devices, or it could feed into a fuel cell to produce electricity.
Just 2.2 pounds (one kilogram) of the aluminum alloy provides 12.9 kilowatt hours of energy when exposed to water. This compares favorably to coal, which yields only 6.7 kilowatt hours.
Furthermore, all of the aluminum that goes into the reaction can be fully retrieved. It just needs to be thrown into a crucible and reprocessed.
“Once you buy aluminum, it’s yours. You never lose it, unlike gasoline that you lose out your tailpipe,” Woodall said.
Despite the efficiency of his system, Woodall is still waiting for someone to capitalize on it. He has spent the last five years refining the properties of the alloy while suggesting applications that would reduce the world’s reliance on oil and coal.
Most recently, he has proposed dropping the aluminum alloy into remote villages that have neither electricity nor clean water. Residents could put the alloy into whatever water they had handy, capture the hydrogen fuel, and then use the heat from the reaction to create steam, Woodall said. Any water collected from the steam would have already been purified and sterilized.