Hydrogen has been mooted about as a power source, attracting interest from various engineers (including rotary engine experts – rumor has it that their Wankel has been modified to successfully run on hydrogen), but it has a few problems, such as transportation and storage. One of the biggest problems has been refinement. Like fossil fuels, hydrogen isn’t easily available in ready-to-consume form, but instead must be refined from an impure form, typically methane (CH4). This takes a lot of heat, and results in the release of that carbon atom into the atmosphere, where it contributes to climate change. In fact, that makes it a non-starter.
NewScientist (8 October 2016) reports on the efforts of scientists to capture that carbon – and a breakthrough may have been achieved. Jon Cartwright reports:
After two years of trial and error, [Alberto Abánades and Carlo Rubbia, a Nobel Prize Winner, ] had what they thought was a viable reactor design: a vessel about the height and diameter of a hockey stick lined with quartz glass and stainless steel and filled with molten tin. Its external foil insulation made it look rather like a domestic hot water tank but it worked: they bubbled methane in at the bottom while raising the temperature of the tin up to 1000 °C, until hydrogen gas spouted continuously from the top.
But the real test was what it looked like inside. After two weeks, Abánades and colleagues switched off the reactor and peered in. Soot had indeed formed, but it had all floated neatly to the tin’s surface, where it could be scraped away like the slag in an ore refinery. “We could even have operated the reactor for a couple more days,” says Abánades. Last year, repeating the experiment at 1200 °C, the team managed to convert nearly 80 per cent of the methane they pumped in into hydrogen (International Journal of Hydrogen Energy, vol 41, p 8159).
Problems remain, such as supplying the power to heat it – but that may be resolvable without too much fuss. It’s an interesting advance towards a hydrogen future.
