Hydrogen has long been hailed as the future of air travel, but with aircraft manufacturers having largely put most of their plans to develop hydrogen burning ‘cryoplanes’ on hold, at least for the moment, that had seemed rather less certain of late. Now, however, all this may be about to change, as new research underway at Glasgow University looks set to pave the way for hydrogen to become the green aviation fuel of tomorrow.
The trick lies in that branch of science which deals with the unbelievably small, while at the same time, itself having huge potential to revolutionise all our lives, namely nanotechnology, and scientists hope to be able to harness its power to allow hydrogen to be stored as a solid. If they can achieve that, then the bright new future so long promised for hydrogen powered aeroplanes may not be so far away after all.
While the catastrophic fire in 1937 that saw the destruction of the Hindenburg airship and the loss of 36 lives has given hydrogen an unfortunate historical association with air travel, there are things in its favour as a modern day alternative to kerosene. It is three times more efficient than oil, although this is somewhat offset by the fact that, even as a liquid, hydrogen is four times more bulky, which obviously makes it less convenient to use, but perhaps its key plus point is its versatility. Hydrogen gas can be burned directly as a fuel itself, or combined with oxygen to produce electricity in a fuel cell – and as an added bonus, in both cases the only ‘emission’ is water, making it a clean energy source in use.
The Stumbling Block
Unfortunately, as Professor Duncan Gregory from Glasgow University’s chemistry department explains, when it comes to turning hydrogen-based technologies into commercial realities, storage is “the largest bottle-neck in the process.” Any attempt to use this energy source, particularly in fuel cells, needs to overcome significant cost and safety hurdles to store the typically large volumes required, something which has always proved a major stumbling block to date – or at least, it has until now.
A Nanotech Solution
Working with EADS Innovation Works – one of the world’s leading aerospace and defence companies – the Glasgow team are attempting to solve this problem once and for all by improving the efficiency of storage tanks. The approach they are exploring involves modifying the composition and structure of the tank at the microscopic level, using some of the latest advances in nanotechnology to do it.
Using a Hydrisafe tank, which was developed by the small start-up company, Hydrogen Horizons, the work will concentrate on replacing the existing storage alloy – made from lanthanum nickel – with other materials, such as magnesium hydride, which have been altered at the nano-scale. The idea is to produce a longer-lasting tank, which can accept and release hydrogen much faster, making it ideal as a way of storing hydrogen in a solid state that will be able to match the high energy demand necessary to run a fuel cell on an aeroplane.
If they are successful in developing an effective way to store solid state hydrogen, it would finally open the way for the full-scale, commercial use of hydrogen as a real alternative to conventional aircraft fuel and revolutionise air travel. The expression ‘paradigm shift’ is a much over-used one, but in this case, it really would be justified.
For now at least, the team are focussing on rather less lofty goals, hoping to be successful enough in their work to be able to fly an unmanned aircraft, powered by a fuel cell, as a demonstration of the new hydrogen storage technology. Once that has been achieved, they hope to attract funding from the government and the EU to take the project on to the next stage.
After that, of course, the sky’s the limit!