New alloy could provide cheap drinking water to villages

The alloy contains aluminum, gallium, indium and tin.

Last Updated: May 04, 2011, 13:49 PM IST

Washington: A new aluminum alloy could convert sea or freshwater into drinking water while also extracting hydrogen to generate power.
Such a technology could help provide power and drinking water to remote villages in Asian and African nations, said Jerry Woodall, Purdue University professor of electrical and computer engineering.

The alloy contains aluminum, gallium, indium and tin. Immersing the alloy in freshwater or saltwater causes a spontaneous reaction, splitting the water into hydrogen and oxygen molecules.

The hydrogen could then be fed to a fuel cell to generate electricity, producing water in the form of steam as a by-product, he said, according to a Purdue statement.

"The steam would kill any bacteria contained in the water, and then it would condense to purified water," Woodall said. "So, you are converting undrinkable water to drinking water."

"There is no other technology to compare it against, economically," Woodall said. "But it`s obvious that 34 cents per kilowatt hour is cheap compared to building a power plant and installing power lines, especially in remote areas."

The technology also might be used to desalinate water, said Woodall, who is working with doctoral student Go Choi.

"Because aluminum is a low-cost, non-hazardous metal that is the third-most abundant metal on earth. This technology promises to enable a global-scale potable water and power technology, especially for off-grid and remote locations."

The potable water could be produced for about $1 per gallon, and power could be generated for about 35 cents per kilowatt hour of energy. The unit, including the alloy, the reactor and fuel cell, might weigh less than 100 pounds.