Today the United States uses more than 90 billion cubic meters (3.2 trillion cubic feet) of hydrogen yearly. Most of this hydrogen is used as a chemical, rather than a fuel, in a variety of commercial applications:
- Commercial fixation of nitrogen from the air to produce ammonia for fertilizer (about two-thirds of commercial hydrogen is used for this)
- Hydrogenation of fats and oils, in which vegetable oils are changed from liquids to solids; shortening is an example of a hydrogenated oil
- Methanol production, in hydrodealkylation, hydrocracking, and hydrodesulphurization
- Hydrochloric acid production
- Metallic ore reduction
- Cryogenics and the study of superconductivity (liquid hydrogen)
Hydrogen’s main use as a fuel is in the space program. Today hydrogen fuels both the main engine of the Space Shuttle and the onboard fuel cells that provide the Shuttle’s electric power.
Hydrogen can be used in fuel cells to power a wide variety of applications, both mobile and stationary, small- and large-scale. Fuel cells can be used to provide clean energy for transportation. And because they are modular, fuel cells can provide heat and electricity for single homes or to supply the energy to run an entire large commercial building, to provide a small amount of electricity to a community grid, or a large amount of electricity to a large grid network.
Hydrogen can be used to generate electricity for our homes and office buildings, through the use of gas turbines and microturbines (small gas turbines). Conventional gas turbines can be modified to run efficiently on hydrogen or hydrogen/natural gas blends. Microturbines can provide high-efficiency reliable power for smaller-scale applications.
Hydrogen can also be used in internal combustion engines for both stationary and mobile applications, powering industrial processes, ocean fleets, cars, and buses. As with gas turbines, conventional combustion engines can be modified to run efficiently on hydrogen or hydrogen/natural gas mixtures for these applications.
Source: U.S. Dept of Energy