Process may enable hydrogen-powered cars

The process, named hydrothermolysis, uses a powdered chemical called ammonia borane, which has one of the highest hydrogen contents of all solid materials, said Arvind Varma, head of Purdue University’s School of Chemical Engineering.

‘This is the first process to provide exceptionally high hydrogen yield values at near the fuel-cell operating temperatures without using a catalyst, making it promising for hydrogen-powered vehicles,’ he said. ‘We have a proof of concept.’

The process combines hydrolysis and thermolysis, two hydrogen-generating processes that are not practical by themselves for vehicle applications. 

Ammonia borane contains 19.6 per cent hydrogen, a high weight percentage that means a relatively small quantity and volume of the material is needed to store large amounts of hydrogen, Varma said.

‘The key is how to efficiently release the hydrogen from this compound and that is what we have discovered,’ he said.

Purdue has filed a patent application on the technology.

In hydrolysis, water is combined with ammonia borane and the process requires a catalyst to generate hydrogen while, in thermolysis, the material must be heated to more than 170°C, or more than 330°F, to release sufficient quantities of hydrogen.