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Laptop Methanol Fuel Cells Promised This Week
securitas writes: "Wired tells us that Germany's Smart Fuel Cell is about to ship the first methanol based fuel cells for laptops and other electronic devices. The company says a 120 milliliter fuel cell can power a 15W notebook for 10 hours, and you can refill it without shutting down."
A lot of people don't seem to've noticed that this unit won't exactly be convenient to carry around. Their 25W prototype is 120x160x170mm (5"x6.5"x7") and 2.8kg (5lb)! That's less than a large desktop-equivalent laptop but almost double the weight of some lightweight models. I don't know how many road warriors will really want to triple their carry weight and pay extra money for a few extra hours of runtime. It will probably seem much more convenient and cost-effective to get one of those LiPoly external batteries or something.
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Methanol is by itself almost completely non-toxic; the danger arises from the metabolic breakdown products.
When you ingest ethanol (aka grain alcohol), alcohol dehydrogenase (an enzyme)catalyzes the oxidation of ethanol to acetaldehyde. If you oxidize acetaldehyde, you get then get acetic acid, which can then be oxidized to carbon dioxide.
Conversly, when you oxidize methanol (aka wood alcohol), you get formaldehyde. If you then oxidize that, you get formic acid. The formaldehyde and the formic acid are both toxic with formic acid being the more toxic of the two. The formaldehyde attacks the sensitive protein in the retina making you blind while the formic acid is what kills you.
Because the rate limiting step in methanol oxidation is availability of alcohol dehydrogenase, the clinical treatment for methanol poisoning is, you guessed it, to give large amounts of ethanol. Because the alcohol dehydrogenase has a higher affinity for ethanol than methanol, giving you ethanol will keep the methanol from being catabolized. The "unprocessed" non-toxic methanol can then be cleared by the kidneys.
Also, it should be noted that the prohibition on distilling has absolutely nothing to do with public safety. It is a taxation issue pure and simple. I suggest you pull out a history text and read about something called the Whiskey Rebellion.
I thought I'd wrap up a number of points in one post rather than make several replies:
"Also, if I'm staying in a hotel, charging my batteries is free."
It's not free, the hotels expect you to do it and build it into the cost. If methanol becomes popular with travellers, the hotel will pop down to the hardware store, buy a couple of gallons of methanol, and offer that free on tap to guests too.
"This will become even worse if cells arrive that run off of pure hydrogen-PEM (proton exchange membrane) fuel cells that run on hydrogen"
All PEM fuel cells run on hydrogen. Methanol based fuel cells simply break down the methanol into hydrogen and its constituent parts before it hits the PEM.
"However, if the methanol charges for the fuel cells are not rechargeable themselves, we will be adding a MORE exhaust to the environment, in the form of the disposed charger."
You don't recharge a methanol cell, you just squirt in more methanol to replace what has been used up.
"Ok, fine methanol works as a safe hydrogen storage method, but I was under the impression that fuel cells use hydrogen AND oxygen to create electricity and as a byproduct create H2O. Where does the water go?"
Methanol is 50% oxygen, 37.5% carbon and 12.5% hydrogen. So yes water will be produced and there must be some drainage tap (so you will have to take your laptop for a pee on the plane). There will also be carbon deposits you will have to dispose of. I wonder also how often the PEM has to be changed, as carbon will clog it up if not effectively filtered out.
There are plenty of fuel cell articles at Future Energies, including how a fuel cell is heating my local swimming pool! Check it out.
Phillip.
Property for sale in Nice, France
I'm sure their "refueling" procedure involves a special tool designed to avoid spills. Methanol can be absorbed through your skin, but if you have a proper system in place you can do it safely. As for using ethanol instead of methanol, you can't just substitute one alcohol for another and expect it to work...