I have basic idea of working of hydrogen fuel cell but why just hydrogen? Isn’t there any better or maybe cheaper alternative?
(I know it’s bit complex for but I would appreciate your answers)
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Burning hydrogen simply produces water, instead of more-dangerous products of other reactions.
There are definitely alternatives.
One benefit about hydrogen is that it’s fairly easy to produce using electricity with electrolysers, and compared to other methods, it’s one of the highest efficiencies at around 70%(but higher is possible, even 99% is possible with solid oxide at some point).
Hydrogen can also be very easily converted back into electricity with fuel cells at a high efficiency. Fuel cells are basically electrolysers but in reverse, which makes them also very efficient (around 60-70%). Burning any other chemical fuel leads to efficiencies around 30% for smaller engines and maybe 50-60% for large plants.
Hydrogen can not really be considered a fuel though, it’s more of a inefficient chemical battery, because there’s very little hydrogen you can just naturally extract from the ground or something like that, so you have to make the hydrogen with electricity.
There’s lots of downsides to hydrogen though, it is extremely low mass density so you need either big space or very high pressure to store and carry it around. High pressure means you lose a ton of energy pressurizing it.
Hydrogen can be used to make other fuels though. If you want to make methane(natural gas) you just take hydrogen and add some co2 + energy and you got it. If you want to make other fuels like jetfuel you can also do that with hydrogen + co2 + energy. Basically hydrogen is a building block for any bio fuel you want to make.
There basically aren’t other options. If you want to cram potential energy into a molecule for storage, and then react that molecule with oxygen in order to release that potential energy on-demand, you’re pretty limited in terms of the kinds of chemical reactions available. Oxygen, hydrogen, carbon, and nitrogen are essentially the only ingredients we know how to bake the cake with, there’s no indication we’re going to discover some magical new element that’ll fill the gap, and (in all honesty) we have quite a few clues from chemistry that there absolutely *isn’t* any other undiscovered element that’ll work for this particular job.
So your options are, essentially, either pure hydrogen, hydrocarbon fuels, or ammonia. Two of those things broadly don’t occur naturally, so you have to make it from other compounds (which costs money). The third (hydrocarbons) absolutely exists naturally (hence why we use it), but presents a problem with respect to introducing carbon to the atmosphere.
We do use other elements like Carbon.
The problem is that if you burn hydrogen you get H2O aka water. if you burn carbon you get CO and CO2 aka carbon monoxide and carbon dioxide. We don’t want more CO2 in our atmosphere.
Hydrogen is not used as a fuel source and more like a battery.
You get electricity from solar or similar, use it to turn water into hydrogen and oxygen and then later turn hydrogen and oxygen back into water and get the energy back.
We have lots of other ways to store energy like this.
The trick is finding one that allows you to store a lot of energy in a small volume and mass, doesn’t involve too much risk of explosion of toxic byproduct being released when opened and is cheap enough.
Water is very cheap.
There are a few types of fuel which may be used more in the future. The advantage of hydrogen is that this is the easiest fuel to make from electricity. So if you have electric power but need a compact, easy to transfer fuel then hydrogen is the obvious answer. The other two candidates for this process is methane and ammonia. Methane takes a lot more energy to make so the process is less efficient. And ammonia is toxic. The current development looks to be to use hydrogen for private fuel sales such as cars, backyard generators, etc. and then ammonia for commercial entities such as for ships, airplanes, and larger generators. All of these fuels are small enough that they can be used with fuel cells but fuel cell technology seams to have been obsoleted by high efficiency batteries.
There are other fuels as well. We currently use a lot of bioethanol which comes from plants. We also have biodiesel which are made from plant oil. And even though it is a bit more complicated a lot of users of coal can use solid biofuel, usually made from wood. These are easier to use today as existing engines can fill up with these fuels without any modifications. But they do require a lot of agricultural area to make.
Hydrogen is abundant.
2/3 of Earth’s surface is water, and water is 2/3 hydrogen.
Hydrogen gas is made by running an electric charge through water, so it’s easy to make, and we can store it for a long time (stable), transport it, and use the energy on demand at a later time.
The problem of hydrogen is price of storage, transportation and fuel cells. This is why fuel cell EVs compete so badly against battery EVs. Fuel cells are expensive. At this moment in history, I really don’t believe fuel cell to be the future.
Hydrogen is an energy storage method as it can be produced from water using electricity and stored for later use. It is not a fuel like oil or coal that can be pumped or mined from deposits (hydrogen has been found in rare geological deposits). The vast majority of hydrogen is created by reforming natural gas.
It’s not so much about the elements, as the molecules. You don’t burn Hydrogen, you burn H2, hydrogen *gas.*
A lot of organic fuels and gas/oil are hydrocarbons, which are oxidized into CO2 and other (often harmful) byproducts. If this CO2 was originally stored in the ground, you are then contributing to overloading the carbon cycle of the atmosphere (plants and animals source its carbon from the air and biosphere, not the deep earth). Hydrogen gas can also be burned/oxidized, but becomes H2O, water.
Additionally, H2 can be refined from both fresh and salt water, which is a near endless source that is restored by *using* said fuel. As a fuel source, one of its big hurdles is that this refining process can be energy intensive, but if you can do it with renewable energy sources (solar/wind/tidal/etc), you can have a clean fuel made cleanly.
Sadly cost is still a big limiter, yeah.
My man there is like only 3 elements in this world that combust: carbon, hydrogen and sulphur.
Each one of them had 33% chance to be fuel of the future. Each of them use oxygen to combust.
Hydrogen + oxygen = water
Guess which one won.
EDIT: dude is asking about why a fuel is considered THE FUTURE in ELI5 and then you go AKCHUALLY iron also oxidises but very slow!. Go hit yourself in the face fedora munchers
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