How hydrogen is made
Most hydrogen is stripped out of natural gas with steam, and it ends up in fertilizer and refineries.
- stations
- 6
- things upstream
- 2
- raw sources
- 2
- step from the ground
- 1
The short version
Most hydrogen comes from natural gas. Methane and steam react over a nickel catalyst in a furnace-heated tube bundle, giving hydrogen and carbon monoxide. A second reaction with steam turns the monoxide into more hydrogen and carbon dioxide, and the hydrogen is purified. Electrolyzers can split water instead.
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Remove sulfur from the gas
Natural gas first passes through a bed that captures sulfur compounds. Sulfur would poison the nickel catalyst downstream.
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React gas with steam
The gas and steam flow down long narrow tubes packed with nickel catalyst, inside a furnace. The reaction soaks up heat, so burners fire constantly to keep the tubes hot.
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Shift the carbon monoxide
A second reactor mixes the gas with more steam. The carbon monoxide is converted into extra hydrogen and carbon dioxide.
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Scrub out the carbon dioxide
A liquid solvent absorbs the carbon dioxide, which is either vented or captured for storage and sale. The gas that remains is mostly hydrogen.
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Purify the hydrogen
Pressure-swing beds soak up the last traces of other gases and leave nearly pure hydrogen. It is compressed and piped to refineries and ammonia plants.
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Split water with electricity
Electrolyzers pass electric current through water and collect hydrogen at one electrode. When the power comes from wind or solar, the product is called green hydrogen.
Goes in
Worth repeating
- Hydrogen made from natural gas and released without capturing the carbon dioxide is called gray hydrogen, and most hydrogen today is gray.
- Steam reforming of natural gas makes almost half of the world's hydrogen, and it is the cheapest method in capital cost.
Back to the ground
Follow every input upstream and hydrogen starts as these 2 raw sources.
Open the whole family tree
Where it goes next
Hydrogen feeds 21 lines directly and reaches 458 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How hydrogen is made." Assembly Line, 2026-11-03. https://assemblyline.org/make/hydrogen