As far as Greenbang understands it, most of cryogenics’ contribution to society centres around forming the basis of Arnold Schwarzenegger’s Mr Freeze character in Batman Forever and lightening Walt Disney’s wallet by a doubtless disgusting amount to keep his head on ice for years.
But now the technology looks like it’s got more to offer (as if ripping off Walt Disney wasn’t enough).
According to scientists at the Lawrence Livermore National Laboratory, cryogenics is now allowing them to put hydrogen in its place – the fuel tank of an experimental hybrid vehicle – and keep it there.
The last thing you want in your hydrogen car, after all, is the fuel escaping from the fuel tank – apparently a big of a problem in some test vehicles. The folk over at Livermore have come up with a cryogenic pressure vessel which can keep hydrogen fuel from venting any vapour for over six days – that’s almost as long as it would take Greenbang to read the Sunday papers.
Here’s more about the miraculous cryogenic vessel:
LH2 [hydrogen fuel] tanks hold super-cold liquid hydrogen at around -420 Fahrenheit. Like water boiling in a tea kettle, pressure builds as heat from the environment warms the hydrogen inside. Current automotive LH2 tanks must vent evaporated hydrogen vapor after being parked three to four days, even when using the best thermal insulation available (200 times less conductive than Styrofoam insulation).
In recent testing of its prototype hydrogen tank onboard a liquid hydrogen (LH2) powered hybrid, LLNL’s tank demonstrated a thermal endurance of six days and the potential for as much as 15 days, helping resolve a key challenge facing LH2 automobiles.
Today’s automotive LH2 tanks operate at low pressure (2-10 atmospheres). The LLNL cryogenic capable pressure vessel is much stronger, and can operate at hydrogen pressures of up to 350 atmospheres (similar to scuba tanks), holding the hydrogen even as the pressure increases due to heat transfer from the environment. This high-pressure capability also means that a vehicle’s thermal endurance improves as the tank is emptied, and is able to hold hydrogen fuel indefinitely when it is about one-third full.