1.)  Why is hydrogen used as a fuel

Hydrogen has the highest energy content per unit weight of any known fuel-52,000 Btu/lb (120.7 kJ/g). It burns cleanly. When hydrogen is burned with oxygen, the only byproducts are heat and water. When burned with air, which is about 68% nitrogen, some oxides of nitrogen are formed.

2.)  What is the hydrogen economy?

The hydrogen economy is a world fundamentally different than the world we know now.

Picture it . . . Hydrogen is available to everyone, everywhere–from the corner fueling station to the large industrial facility on the outskirts of town.

Hydrogen is produced, cleanly and cost-effectively, from a variety of sources including renewables, such as biomass and water, as well as nuclear energy and fossil fuels, using advanced technologies to ensure that any carbon released in the process does not escape into the atmosphere. Hydrogen is delivered and stored routinely and safely.

Hydrogen-powered fuel cells and engines are as common as the gasoline and diesel engines of the late 20th century–they power our cars, trucks, buses, and other vehicles, as well as our homes, offices, and factories.

Companies that for decades invested in hydrogen technologies now export commercial products and services around the world. And developing countries have access to clean, sustainable, and economical hydrogen-based energy systems to meet their growing energy demands.

There are many challenges to building a hydrogen economy. It’s not a vision that will be realized tomorrow, next month, or next year–but it is achievable, and together with its partners, the Department of Energy is working to make it happen.

3.)  If both hydrogen and oxygen are flammable, then why doesn’t water burn?

Hydrogen and oxygen will burn to form water if in an appropriate mixture. Pure hydrogen by itself and pure oxygen by itself will not burn (hydrogen needs an oxidizer and oxygen needs a reductant). Water (H2O) is a stable chemical compound that does not have the characteristics of the elements that make up its composition (hydrogen and oxygen). This is true of most chemical compounds.

4.)  Who was the first person to successfully split water to produce hydrogen?

The first recorded splitting of water to produce hydrogen and oxygen was accomplished by Sir William Grove in 1839. He also discovered the fuel cell in the same year. He combined three fuel cells in series and connected the cells to two electrodes in an acid solution, which resulted in water splitting.

5.)  If we use hydrogen for all our energy needs, will we run out of oxygen?

The ultimate source of hydrogen is water-when producing hydrogen, we would also produce oxygen, which would both be consumed in the same ratio as produced. So there would be no depletion of oxygen from the atmosphere.

6.)  How is hydrogen produced?

Most of the hydrogen produced in the United States is made by steam reforming of natural gas, which is currently the most cost-effective way to produce hydrogen. There are many other ways to produce hydrogen, such as extracting it from the Black Sea which is the least cost effective and will generate huge amounts daily.

7.)  Who discovered hydrogen?

Henry Cavendish (1731-1810) was an English chemist and physicist who spent several years studying the properties of hydrogen and carbon dioxide. In 1766 he discovered that hydrogen was a separate substance. He was the first chemist to produce water from hydrogen and oxygen and to understand that the production of water was essentially related to the loss of the combined weights of the gases.

8.)  If hydrogen comes from water, then why can’t we put water in our car?

Fuels are by nature reactive, but water is not very reactive. You would need to have hydrogen or some other reactive fuel mixture, such as gasoline or natural gas, to extract energy in a efficient manner.

9.) How does hydrogen compare with other fuels like gasoline and diesel?

  • Hydrogen can be totally nonpolluting (water is the exhaust).
  • Hydrogen can be economically competitive with gasoline or diesel.
  • Hydrogen can be as safe as gasoline, diesel, or natural gas.
  • Hydrogen can help prevent the depletion of fossil fuel reserves.
  • Hydrogen can be produced in any country from a variety of energy sources.