Hydrogen explained Hydrogen production

Hydrogen production

To use hydrogen, it first must be separated from the other elements it’s combined with in molecules. Hydrogen can be produced from many different sources and in various ways for use as a fuel. The two most common methods to produce hydrogen are steam-methane reforming and electrolysis (splitting water with electricity). Researchers are exploring other hydrogen production methods, or pathways.

Steam-methane reforming

Steam-methane reforming is the process used for nearly all commercially produced hydrogen in the United States. Commercial hydrogen producers and oil refineries use steam-methane reforming to separate hydrogen atoms from carbon atoms in methane (CH₄), the main component of natural gas. High-temperature steam (1,300°F to 1,800°F) under pressure reacts with methane with the help of a catalyst (a substance that speeds up a chemical reaction) to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide (CO₂).

Industrial facilities and petroleum refineries primarily use natural gas as the methane source for hydrogen production. Several fuel cell power plants in the United States treat and use landfill gas (biogas) as a hydrogen source. Biofuels and petroleum fuels are also potential hydrogen sources.

Electrolysis

Electrolysis splits hydrogen from water using an electric current. Electrolysis is commonly used in high school science classes to demonstrate chemical reactions and hydrogen production. On a large, commercial scale, the process is sometimes called power-to-gas, where electricity is power and hydrogen is gas. Electrolysis is a clean process, producing only hydrogen and oxygen, with no other byproducts or emissions. The electricity for electrolysis comes from the electric power grid, which is supplied with a mix of renewable sources, nuclear energy, and fossil fuels.

Other methods

Scientists are actively researching and developing new methods for hydrogen production, including:

• Thermochemical: Converting biomass into gas or liquids and then separating the hydrogen
• Photolytic: Using solar energy to split water into hydrogen and oxygen
• Biological: processes that use microbes, such as bacteria and microalgae, to produce hydrogen through biological reactions

Clean hydrogen production

The U.S. Department of Energy (DOE) supports source-neutral hydrogen production pathways, which means DOE does not use the color code others use to categorize hydrogen based on its source, production method, or carbon capture.

DOE's Hydrogen Program includes a number of programs for clean hydrogen production. Two of the major DOE initiatives are:

• The U.S. National Clean Hydrogen Strategy and Roadmap
• A clean hydrogen production standard