Future cars running on clean fuel technology would not require gaseous hydrogen, according to a recent study by a scientist from Yale University.
According to him, future cars can carry hydrogen in a liquid form like gasoline, which essentially means that the same liquid fuel infrastructure that is presently used at gas stations could suffice for fuelling cars.
Advertisement"By using a liquid, we simplify the engineering," Nature quoted Robert Crabtree, who presented his findings this week at the American Chemical Society meeting in Boston, Massachusetts, as saying.
Most research on hydrogen storage and transport has focused on materials called metal hydrides and, recently, on metal-organic-frameworks (MOFs) — incredibly porous materials that can be stuffed full of gas.
But getting enough hydrogen into these frameworks to make a fuel tank of reasonable size and weight is problematic, and getting the fuel in and out would require novel fuelling systems.
Crabtree's system on the other hand envisages a system that uses a standard petrol tank containing an organic liquid.
This liquid is passed through a heated module containing a catalyst, which then unlocks the hydrogen and releases it a little at a time to be used as fuel.
The remaining dehydrogenated liquid can then be removed at a filling station and whisked away to be reprocessed - the liquid can be hydrogenated and rehydrogenated repeatedly - making it re-usable.
Elsewhere, the tank can always be refilled with fresh, hydrogenated liquid, he said.
Crabtree said incorporation of nitrogen into the organic liquids would take care of the high temperature required (an increase of about 600 degrees Celsius) to unlock the hydrogen.
Nitrogen binds to hydrogen less strongly than carbon does, and the presence of nitrogen within a carbon-based ring weakens the remaining C-H bonds.
According to Crabtree, these weakened bonds make it easier to get hydrogen out as the liquid passes over a catalyst, and lower operating temperatures would be needed - the material would only need to be raised by 50 degrees Celsius.