Why Can't Fuel Cells Simply Use Water to Generate Hydrogen?

In summary, the conversation discusses the concept of fuel cells and the potential drawbacks of using them due to the limited availability of hydrogen. The individual suggests using water as a source of hydrogen and proposes a process of splitting water, using the hydrogen in fuel cells, and then returning it back to water. However, it is pointed out that the energy required to split water is greater than the energy produced when burning the hydrogen. This is due to losses in various stages of the process. Ultimately, the conversation ends with the question of where to obtain the energy needed for the electrolysis process.
  • #1
Red Ninja
1
0
I was wondering if you could recommend an article that would explain a concept to me. That is: the drawback of fuel cells, reportedly, is that hydrogen is not readily available. However, I am wondering why it is that if the original idea of fuel cells came from reversing the concept that hydrogen could be separated from water, why can't fuel cells take water, separate the hydrogen, separate the electrons and then merge them all back together at the other end of the circuit? Basically borrowing the hydrogen electrons for a minute and then returning them back to the water?
 
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  • #2
Why not take a battery, use electricity from it and then return it back to the battery? There are always losses in a system, usually larger than the net output.

If you search around a bit, there have been a few good threads about this in the last couple months with a few links to good websites. Would be worth the effort to search this forum a bit.

Cliff
 
  • #3
Red Ninja said:
However, I am wondering why it is that if the original idea of fuel cells came from reversing the concept that hydrogen could be separated from water, why can't fuel cells take water, separate the hydrogen, separate the electrons and then merge them all back together at the other end of the circuit? Basically borrowing the hydrogen electrons for a minute and then returning them back to the water?[/FONT][/SIZE][/COLOR]
Splitting water: 2H20+ENERGY->2H2+O2

Burning hydrogen: 2H2+O2->2H2O+ENERGY

As you can see, the reactions are mirror images of each other: the energy is exactly the same in each.
 
  • #4
russ_watters said:
Splitting water: 2H20+ENERGY->2H2+O2

Burning hydrogen: 2H2+O2->2H2O+ENERGY

As you can see, the reactions are mirror images of each other: the energy is exactly the same in each.

The energy used to split water is the same to the energy produced in the burning process. But, the total amount of energy NEEDED to split water into hydrogen + oxygen is a lot bigger then the energy can be USED when we burn the hydrogen.

We have losses in the power plant, transmission grid, chemical reactor in which we split the water, etc.

In the other end, there is losses in the burning process etc.
 
  • #5
You can certainly electrolyze water to produce hydrogen, which can then be used in fuel cells. The problem, of course, is where do you get the energy to electrolyze the water?

- Warren
 

Related to Why Can't Fuel Cells Simply Use Water to Generate Hydrogen?

1. What is a fuel cell?

A fuel cell is an electrochemical device that converts the chemical energy of a fuel, such as hydrogen, into electricity. It works like a battery, but unlike a battery, it requires a continuous supply of fuel and oxygen to sustain the chemical reaction.

2. How does a fuel cell work?

A fuel cell works by combining hydrogen (or another fuel) and oxygen in an electrochemical process. The fuel is fed into the anode side of the cell, where it reacts with a catalyst to produce positively charged hydrogen ions and negatively charged electrons. The hydrogen ions then travel through an electrolyte to the cathode side of the cell, while the electrons are forced to travel through an external circuit, creating an electrical current. At the cathode, the hydrogen ions and electrons combine with oxygen to form water and heat, the byproducts of the reaction.

3. What are the advantages of fuel cells?

Fuel cells have several advantages over traditional combustion engines. They are more efficient, producing less waste heat and using less fuel to generate the same amount of electricity. They also have lower emissions, as the only byproduct of the reaction is water. Additionally, fuel cells can be powered by a variety of fuels, including hydrogen, natural gas, and biofuels, making them a versatile and sustainable energy source.

4. What are the limitations of fuel cells?

One major limitation of fuel cells is their cost. They are currently more expensive than traditional combustion engines, making them less accessible for widespread use. Another limitation is the need for a continuous supply of fuel and oxygen, which can be challenging to maintain in certain situations. Additionally, the production and storage of hydrogen, a common fuel for fuel cells, can also be expensive and require specialized infrastructure.

5. How are fuel cells being used today?

Fuel cells are currently being used in a variety of applications, including powering vehicles, buildings, and portable devices. In the transportation sector, fuel cell vehicles are being developed and used as an alternative to traditional gasoline-powered cars. In buildings, fuel cells are being used for backup power and combined heat and power systems. They are also being used in portable devices, such as laptops and smartphones, to provide a longer-lasting and more sustainable source of energy.

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