Scott: I don't have any "reasoning" why methanol has less power than gasoline, I just know the facts: Methanol has about 9800 Btu's per pound, versus about 22,000 for gasoline. I think it is because methanol has some oxygen in its molecular structure, and so is already partially oxidized, but I am not a chemist so there may be some other reason. Another poster could probably explain this better.
Separating hydrogen from gasoline is no big deal to do. The issue is, at what cost? Gasoline has to be heated up to about 1800 degrees F, run by a catalyst, injected with steam, and various other steps to create a stream of hydrogen free of carbon monoxide, which will poison a PEM fc, and then the hydrogen stream must be run through heat exchangers to cool it down to room temperature so as not to melt the membrane.
Methanol will give up its hydrogen at much lower temperatures, which makes that fuel cheaper in terms of equipment needed and energy consumed. The trade-off, of course, is that gasoline is everywhere, and someone is going to have to subsidize placing methanol everywhere, if they want people to buy fc cars. (About a year ago I got roundly attacked for saying that here, but I haven't heard any sensible refutation. I don't think there will be big demand for fc cars unless potential buyers know that they can drive wherever they want and will be able to refill the tank. Having a few selected gas stations in a few cities carrying the stuff ain't gonna fly. This will cost someone a lot of money until there are enough fc cars on the road to use that inventory.) |
