---

Researchers at Purdue University, Indiana, claim that they have developed a process to extract hydrogen from seawater, which could then be fed directly to an internal combustion engine.

The technique had previously worked only for freshwater, but a new formulation is said to also enable the method to generate hydrogen from seawater.

The new development means, in theory, that it would no longer be necessary to store or transport hydrogen on board a ship for power generation - a major challenge in using hydrogen to power ships up until now.

Commenting on the breakthrough, Jerry Woodall, a professor of electrical and computer engineering at Purdue University said "This is important because it might have many marine applications, including cruise ships and tankers."

"We generate the hydrogen on demand, as you need it. It also eliminates the need to store fresh water when used for marine applications."

The method for hydrogen extraction involves using aluminium and a liquid alloy. Woodall's team of researchers have been developing aluminum-based alloys that generate hydrogen from water since 2007. The Purdue Research Foundation has also filed a separate provisional patent application on the new process for seawater.

During the process, the aluminium reacts with oxygen atoms in water molecules, thus freeing the hydrogen. The waste product, aluminium hydroxide, can be recycled back to aluminium using existing commercial processes.

According to Woodall, the technology also represents a new way of storing energy from solar and wind power because waste produced in the process could be recycled using wind turbines and solar cells.

"Being unable to store energy from wind and solar has been a major limitation for those technologies because they don’t work very well when the sun isn’t shining and the wind isn’t blowing," said Woodall. "But if we converted energy from wind and solar into fuel for hydrogen-generation, we would, in effect, be solving this problem because the hydrogen could then be used to generate electricity, to run engines or fuel cells."

The material used in the process is made of small grains of aluminium surrounded by an alloy containing gallium, indium and tin, which is liquid at room temperature. The liquid alloy dissolves the aluminium, causing it to react with the seawater and release the hydrogen.

Rather than using powdered aluminium, which has been used in other techniques to generate hydrogen using aluminium, Purdue's team of researchers chose to use bulk metal for 'practical' reasons because powder was said to be 'too expensive and cumbersome'.

"We believe the process is economically competitive with conventional fuels for transportation and power generation," said Woodall.

"Since aluminium is low-cost, abundant and has an energy density larger than coal, this technology can be used on a global scale and could greatly reduce the global consumption of fossil fuels. Also, by co-locating a solar farm or wind turbine complex and an aluminium smelter at a utilities plant, the smelter could be operated around the clock using utility electricity during off-peak times," added Woodall.