Why Hydrogen is the Only Fuel for Fuel Cells

In summary, fuel cells can run on various hydrocarbon fuels, not just hydrogen, and different types of fuel cells exist that can extract hydrogen from these fuels and use it with oxygen to generate electricity. Nitrogen and oxygen are not suitable fuels for fuel cells, with nitrogen being inert and oxygen being used as the "hydrogen acceptor." Additionally, nitrogen can react with other elements in some cases, but due to its triple covalent bond, it is generally considered an inert gas.
  • #1
Imparcticle
573
4
My chemistry book says it is impossible to use anything but hydrogen in a fuel cell, but does not say why. does anyone know why?
 
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  • #2
Thats just how the engine works. Just like your car engine will only run on gasoline, that's what its designed to run on.
 
  • #3
my friend wants to know if its possible to make a fuel cell that runs on nitrogen and oxygen. Is that possible?
 
  • #4
Your book is wrong. There exist a whole class of fuel cells that can run on other hydrocarbon fuels. So-called direct methanol and direct ethanol fuel cells can operate from methanol and ethanol.

Fuel cells are really just devices with semipermeable membranes that are permeable to protons (hydrogen ions) but not to electrons. It doesn't matter where these protons come from, either molecular hydrogen or some other hydogen-containing compound.

Nitrogen and oxygen, of course, contain no hydrogen. They cannot be used in a fuel cell. I should also note that oxygen is used in all fuel cells as the "hydrogen acceptor." Nitrogen itself is an inert gas and has no relevance to fuel cells. Even more importantly, such a fuel cell would actually produce very toxic NOx compounds as exhaust. That's not exactly the direction we'd like to see energy production going.

- Warren
 
  • #5
Hmm... I though it could only run on hydrogen and oxygen. Neat.
 
  • #6
http://www.cfdrc.com/applications/fuelcells/dmfc.html

- Warren
 
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  • #7
don't forget phosphate FCs, carbonate FCs, and solid oxide FCs

http://www.chuden.co.jp/english/corporation/press/pre2000/pre0911.html
http://www1.elsevier.com/vj/fuelcell/show/latest_toc.htt
 
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  • #8
Correct me if I'm mistaken here, but don't all these different types fo fuel cells just extract the Hydrogen from these fuels, and then run on Hydrogen and Oxygen?
 
  • #9
actually produce very toxic NOx

why is it toxic? what makes a gas inert?
 
  • #10
LURCH said:
Correct me if I'm mistaken here, but don't all these different types fo fuel cells just extract the Hydrogen from these fuels, and then run on Hydrogen and Oxygen?
That was my interpretation of Imparticle's chemistry book. It may be an oversimplification the way its written, but it is technically true.
 
  • #11
Imparcticle said:
why is it toxic?
"Toxic" just means "poisonous." I'm not sure if you are looking for how exactly it effects the body, but I'm pretty sure they displace oxygen.
what makes a gas inert?
Inert means non-reactive. Oxygen likes to burn, so its not inert. Nitrogen doesn't react with much of anything (when in diatomic gas form), so it is. There are varying derees though...
 
  • #12
how does nitrogen occur naturally? (monoatomic?)

Inert means non-reactive. Oxygen likes to burn, so its not inert. Nitrogen doesn't react with much of anything (when in diatomic gas form), so it is. There are varying derees though...

BUT what makes it inert? i know what inert means, I just don't know what makes gases inert. Does it have something to do with the electron orbits?
 
  • #13
nitrogen is about 3/4 of the atmosphere, more or less, and it is diatomic

yes, in effect, all the other fuel cells mentioned use hydrogen but react it with something other than diatomic oxygen

here is a better description http://fuelcells.si.edu/basics.htm
 
  • #14
Imparcticle said:
BUT what makes it inert? i know what inert means, I just don't know what makes gases inert. Does it have something to do with the electron orbits?
Yes, chemical reactions are all about electrons. IIRC, the "noble gases" are the most inert because they have their outer shells completely filled, meaning they have no spaces to accept electrons, nor extra electrons to give. I'm not sure about the electron config of nitrogen (not a noble gas).
 
  • #15
As I understand, nitrogen is inert because the triple covalent bond (?) that it's usually in already is so strong. You can get it to react with something else (that's where you get ammonium and TNT), but it's hard.
 

1. Why is hydrogen the only fuel used in fuel cells?

Hydrogen is the most abundant element in the universe and has the highest energy content per unit mass compared to other fuels. Additionally, when hydrogen is used in a fuel cell, it only produces water as a byproduct, making it a clean and renewable energy source.

2. Can other fuels be used in fuel cells?

While hydrogen is currently the most commonly used fuel in fuel cells, other fuels such as methanol, ethanol, and natural gas can also be used. However, these fuels must undergo a reforming process to extract the hydrogen, which adds complexity and cost to the fuel cell system.

3. How does a fuel cell convert hydrogen into electricity?

A fuel cell works by combining hydrogen and oxygen in an electrochemical reaction, producing electricity, water, and heat. This process, known as hydrogen fuel cell technology, involves passing hydrogen ions through an electrolyte membrane, which creates a flow of electrons that can be harnessed as electricity.

4. What are the advantages of using hydrogen in fuel cells?

Hydrogen fuel cells offer several advantages over traditional fossil fuels. They are more efficient, producing electricity at a higher rate, and have a longer lifespan. They also emit no harmful pollutants, making them a cleaner and more sustainable energy source.

5. Are there any challenges to using hydrogen as a fuel for fuel cells?

While hydrogen fuel cells have many benefits, there are also some challenges to consider. One major challenge is the cost of producing and storing hydrogen, as it currently requires a significant amount of energy. Another challenge is the lack of infrastructure for distributing and refueling hydrogen, which limits its widespread use as a fuel source.

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