- Sep 17, 2008
Methane is essentially natural gas and requires high-pressure storage. Propane and butane will liquify under lower pressures and are easier to store.Alright, point taken - hydrogen is difficult to store compactly. Meanwhile, methane, propane, butane are significantly easier to store, while having comparatively lower carbon content relative to other hydrocarbons - that means less CO2, and also less engine coking problems. They also offer comparatively higher specific impulse, though not as high as hydrogen.
I'm no chemist, but I believe that none of those generate the energy per pound that gasoline does, meaning that you'll burn more of them per mile and likely emit just as much CO2 as the gasoline does. No gains there. I had a dual-fuel truck years ago, gasoline and propane, and the thing had considerably less power running on the propane.