Gasoline fuel cells... whatever happended to them? 3

[jmw]

Browsing my old links to wind energy for some reason this link is still live and points to:

U.S. unveils technology for pollution-free cars

a gasoline fuel cell that can also use methanol ethanol etc so is receptive to bio-fuels (Meat prices are about to surge in the UK due to (a) the bad summer or lack of it and (b) the competition for bio-fuels....about time someone wiped out the remaining Orang Outang's forests for palm oil crops so we can keep meat prices down.... just kidding)

So what ever happened to this concept? Is it that any fossil fuel burning is axiomatically bad?


JMW

http://www.ViscoAnalyser.com

 

[GregLocock]

In order to use a hydrocarbon in a fuel cell you first have to strip the hydrogen away from the carbon chain. This is done in a reformulator, the design of which is very complex, and the efficiency doesn't rise much above 80%, rather less for anything that will actually fit in a car and process enough fuel.

The carbon is then oxidised andexhausted as CO2.

The efficiency of fuel cells is claimed to be 80%, again, 60% seems more likely.

So, the net efficiency of a gas powered fuel cell car is about that of a diesel engine, or a Prius engine. And the emissions will be identical.









Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[moltenmetal]

There are such things as direct methanol fuelcells, but Greg's right- there's no such thing as a direct gasoline fuelcell nor is there ever likely to be.

Onboard gasoline/diesel reformers for vehicles (to generate low-CO hydrogen to supply PEM fuelcells) have been abandoned by just about everybody looking into them for very good reasons. Reforming technology is mature (having been used industrially for some 80+ years) and we're unlikely to see any technological breakthrough that makes them make sense for transportation applications. Even the vastly simpler process of reforming methanol into low-CO hydrogen has been pretty much abandoned in favour of high pressure onboard hydrogen storage.

Since the distribution and on-board storage of hydrogen as a fuel is both costly and energetically lossy to the point of negating all (or more) of the efficiency benefit offered by a fuelcell, I wouldn't be holding my breath for hydrogen cars any time soon. Once we've replaced 100% of our stationary power requirements with renewables and/or nuclear and have excess electrical generation capacity with nothing for it to do but make hydrogen, perhaps it'll be worth considering. But while hydrogen is generated from fossil fuels by reformation, hybrid IC vehicles make much more sense from an energy efficiency and emissions standpoint. In the meantime, the "hydrogen economy" is fueled by an equimolar mixture of wishful thinking and hype. It's a distraction from what we should be doing to deal with global warming: reducing the gluttonous waste of energy inherent in dragging two tonnes of steel and an acreage of frontal area around with each person everywhere they go!

 

[SnTMan]

And I believe that, regardless of fuel source, fuel cells are still godawful expensive.

Regards,

Mike

 

[Dinosaur]

I have been trying to explain to my coworkers that hydrogen fuel cell technology is more hype than they realize. You fellows sound as if you are more in tune with the physics of the problem. Can you share your comparative knowledge of the relative performance of the gasoline and fuel cell options. Thanks.

 

[CptHk]

Dinosaur,

On a nearby thread SomptingGuy gave me this link and it has exactly the information you are looking for, although it takes effort to find it.

(

http://ies.jrc.cec.eu.int/wtw.html

)

 

[Dinosaur]

Thanks. I popped over there and you are correct. It will take some work to get my answers out of there. It was worth a star anyway.