Monday, October 03, 2005

Hydrogen Redux

Oh, one more thing. There is a great way to combine the advantages of fuel cell cars and petrol-driven cars:

The onboard reformer.

It's a gizmo that's fueled by any hydrocarbon - methanol usually. Methanol is timber spirit, closely related to ethanol which is vodka concentrate, but highly toxic. With the exception of drinking, it can be used just about anywhere ethanol can. So we can keep our liquor reserves for ourselves.

A methanol molecule is made up of carbon, hydrogen and oxygen. When you do some exciting chemical things to it, you get pure hydrogen, plus CO2. The hydrogen then goes into the fuel cell, and you know the rest of the story.

You still have the CO2 problem to deal with, but you get a lot less of that per mile than with an internal combustion engine; and besides, CO2 isn't the biggest offender. What gets you is the CO, which is the reason people die when they breathe in smoke (it prevents blood from carrying oxygen to cells), plus various nitrogen oxides - collectively called NOx, which is really surprisingly appropriate. Additionally, you have to remember that the whole process starts with methanol, which you get from plants, which absorb CO2. And if you really want to do something about it, there are technologies like Volvo's concept car, which had a CO2 extractor that ran off a solar battery in the sunroof; they calculated that in a typical urban drive pattern, the car got rid of as much CO2 as it made. The extractor produced oxygen plus coal dust, which went into a separate bag. You can give that to your least favorite nephew.

The best thing about the reformer is that it's self-contained; you put methanol in on one end, and get a moving car on the other. Methanol is every bit as easy to handle as petrol, and it's easy to produce in mass quantities (see Part III). The technology needs polishing to adopt it to cars, but otherwise it works. Today.

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