How hydrogen is used as fuel from air?

Question

how can we separate hydrogen from air or water and also how hydrogen is used as a fuel

Answer 1

Have an actual news segment from a local Fox news channel out of Clearwater Florida where a man uses hydrogen as a cutting alternative to acetylene. He obtains the hydrogen from splitting the water molecule using electrolysis. It shows him driving a car rigged to use hydrogen (from water)or gasoline. He claims when using the water/hydrogen he gets about 100 miles per 4 ounces of water. His name is Denny Klein and his business is called Hydrogen Technologies. If someone wants to see the segment I can try to attach it to an email.

Answer 2

Hydrogen is very reactive and combines with other elements such as oxygen to form other compounds, most commonly water when it combines with oxygen.

It requires approximately 50 kilowatt hours of electricity to separate from water an amount of hydrogen with  the energy equivalent of one gallon of gasoline.

When that amount of hydrogen is used in a fuel cell you recover approximately 15 to 18 kilowatt hours of energy.

The process is relatively inefficient and you have a rather large net loss of energy.

Where electrical energy is used to produce hydrogen for use as a fuel is at night when you have a large excess of generating capacity and that electrical energy would otherwise be wasted.

This is done in France where over 80% of their electricity is produced in nuclear power plants.

At night they use the excess generating capacity to produce hydrogen which is then used in buses the next day.

If you use the electricity to produce hydrogen you recover some of the energy.

A more efficient process would be to use excess generating capacity at night to charge the batteries of electric cars.

Answer 3

Hydrogen is a flammable gas. It burns just like natural gas. Burning is a chemical reaction with oxygen. Hydrogen chemically combines with oxygen to make water and at the same time give off energy in the form of heat. That heat can be used to boil water in a steam engine or to make high pressure steam directly inside a piston in an internal combustion engine (like a regular car engine for example).

There is no hydrogen in the air, so you cannot separate it from the air, but water can be broken down with electricity into hydrogen and oxygen gas in a process called Electrolysis. The only problem with that is that it takes a little more energy to break the water down into hydrogen and oxygen than you can get by burning the hydrogen and oxygen. So unless we find hydrogen gas wells, we cannot get any energy from hydrogen, we can only store energy by using another energy source, like solar power or nuclear power, to break water into hydrogen and oxygen for later use. Most hydrogen in use today is made from natural gas. The process is not any cleaner than just burning the gas directly, and anyway natural gas in not a renewable resource; it will run out some day.

Answer 4

You can separate hydrogen from water by either reacting it with a hydrocarbon (steam reforming) or by cracking the water molecule by adding energy (usually electrical energy in a process called electrolysis, but it can also be done with heat at very high temperatures).  Currently, steam reforming is the most efficient, and is the only process used for commercial generation of hydrogen.  

There is not enough hydrogen in the atmosphere to make separation a viable alternative.