Hydrogen Production
Hydrogen can be produced from a diverse range of domestic feedstocks using both traditional and renewable sources.
While most hydrogen produced today is derived from fossil fuel sources, there is increased investment and policy support driving clean hydrogen production and development. FCHEA supports a pathway agnostic approach and our members represent the full spectrum of these various production pathways.
The Hydrogen Color Spectrum
Hydrogen production is commonly categorized using a color spectrum, where each color signifies a distinct method of production. This color-coded system helps to distinguish the environmental impacts and technological processes associated with each type of hydrogen production. While color can be useful to separate different types of hydrogen production in loose categories, it is not the end-all-be-all.
Grey Hydrogen
Fossil-Based Hydrogen
Many industries have been utilizing hydrogen for decades, what is commonly called grey hydrogen. Grey hydrogen is generated by either steam methane reformation (SMR) or autothermal reformation (ATR) which applies steam and heat to natural gas to break the fuel into its component parts of carbon and hydrogen. That hydrogen is then captured and harnessed for use. This pathway can have higher carbon intensities if the carbon generated during the process is not captured and utilized itself. The carbon intensity of hydrogen from grey hydrogen or other fossil fuel-based pathways can be reduced significantly by using biogas or other renewable fuels as feedstock.
Blue Hydrogen
Fossil Hydrogen with Carbon Capture
The production process typically referred to as blue hydrogen takes existing or newly built SMR or ATR facilities and adds carbon capture and sequestration (CCS) equipment. When adding CCS technologies to traditional hydrogen production pathways, the carbon intensity of the hydrogen generated is dramatically reduced.
Green Hydrogen
Electrolysis from Renewable Electricity
Green hydrogen is a means of generating zero-emission carbon intensity hydrogen by using renewable solar or wind power to power an electrolyzer. An electrolyzer is an electrochemical device that uses electricity to break down water into its component elements of hydrogen and oxygen. The hydrogen is then captured and stored for later use.
Turquoise Hydrogen
Methane Pyrolysis
Methane pyrolysis is another method of producing hydrogen from natural gas. However, pyrolysis is unique in that while it does use heat to break down the natural gas into hydrogen and carbon, rather than producing carbon as a gas for capture and sequestration, the process instead generates a solid carbon black byproduct. This production pathway of hydrogen is often referred to as turquoise hydrogen. Carbon black is a key industrial commodity used in a wide range of products including tires, rubbers, plastics, printing inks, and more. The process of creating carbon black when generating hydrogen greatly reduces the carbon intensity of this pathway.
Pink Hydrogen
Nuclear Hydrogen
Pink hydrogen is another means of using electrolysis to generate hydrogen, with the key difference being that the electricity used to power the electrolyzer equipment is derived from nuclear power. This pathway is often designated with its own color designation as this pathway can utilize the very high heat of the nuclear reactors to increase the efficiency of the electrolyzer outputs. As there is no carbon emissions generated from nuclear power, this hydrogen production pathway is also zero-emissions.
White Hydrogen
Naturally Occurring Hydrogen
White hydrogen is another name for hydrogen that is naturally found in the environment. Also referred to as geologic hydrogen, it is produced through natural reactions in the Earth. This method of hydrogen production is still very early in development, but shows great promise, as significant deposits of hydrogen have been found on multiple continents. Some also refer to this form of hydrogen as gold hydrogen.
Clean Hydrogen Production Pathways
Clean hydrogen is a catchall for the wide-range of ways to produce hydrogen with lower carbon intensity, encompassing many of the above production pathways and colors. The U.S. Department of Energy defines clean hydrogen as any hydrogen that is any hydrogen that is under 4 kilograms of carbon dioxide for every 1 kilogram of hydrogen.
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