Brew your own

tauringhuang.

Jul 30th 2008
From Economist.com

Home-brew kits for hydrogen may bring it back into contention as a vehicle fuel

ITM Power

Gas-guzzlerA FEW years ago, the race to replace the petrol-driven internal-combustion engine was dominated by hydrogen. Fuel cells, which mix hydrogen with oxygen to produce electricity and water, were the darlings of the technological world. The crowd, however, is fickle, and the favoured technology now is the lithium-ion battery. One battery-powered sports car, the Tesla, is already on the market, and others are expected to join it soon. Mainstream battery cars should follow in a year or two. Hydrogen, it seems, is fading fast.

Not if ITM Power has anything to do with it. This British firm, based in Sheffield, thinks that hydrogen is still the fuel of the future. It differs from others who cleave to that view in that it also thinks that instead of being delivered by an expensive, new infrastructure of pipes and storage tanks, the gas will be brewed at home by car owners using water, electricity and ITM’s proprietary technology.

The brain behind this idea is Donald Highgate, a polymers expert, who made his name in the 1970s by developing soft contact lenses. The polymer he has come up with this time is used to make what are known as proton-exchange membranes. These, depending on how the device containing them is set up, can act as the guts of a fuel cell or as its opposite, turning water and electricity into hydrogen and oxygen.

That process is known as electrolysis, and normal commercial electrolysers are chunky units placed next to power stations to produce industrial quantities of hydrogen for the chemical industry. They rely on platinum, a metal that costs twice as much as gold, to catalyse the reaction.

Existing fuel cells intended for cars are not quite so greedy. They use some platinum, but also involve membranes made of a polymer called Nafion. However, these membranes cost $500 a square metre.

ITM’s new material costs a hundredth of that, and no platinum is involved. Moreover, its superior conductivity allows the use of a thicker, more robust membrane that will last longer than one made of Nafion. The firm has also patented a simple, one-step manufacturing process: the liquid polymer is poured into a bag before being cured, a bit like an injection-moulded waffle.

Making hydrogen at home, using one of these membranes, gets around the problem of a lack of hydrogen filling stations. In effect, hydrogen becomes a way of storing off-peak electricity. The result can be pumped into your car and run through a fuel cell—or even burned in a conventional internal combustion engine.

And for demonstration purposes, that is the route ITM has taken. It recently showed off a converted Ford Focus. At the flick of a switch this vehicle went from petrol to hydrogen fuel with no perceptible change in its handling. That is probably not the future, although no less a firm than BMW is experimenting with hydrogen-burning versions of the engines for its upmarket cars. But ITM, with its own dual-use technology of electrolyser and fuel cell, will certainly not mind seeing the back of the internal-combustion engine altogether.

If hydrogen turns out not to be the future of motoring in any shape or form, the firm has back-up plans. It has already signed a deal with the American navy to develop a fuel cell to power unmanned mini-submarines, and it is working with Boeing to design a refuelling station for fuel-cell-powered unmanned aircraft. One way or another it believes that hydrogen, home-brewed or otherwise, will form part of somebody’s future somewhere.