Maybe you’ve heard of “green hydrogen.” There’s been a lot of press lately about projects to produce hydrogen to use as an alternative fuel, and the Inflation Adjustment Act provides tax credits for production of “green hydrogen.” But did you know that there are other hydrogen “colors”? An excellent article from MartenLaw.com provides a summary of the methods and tax credits and regulations being developed for green hydrogen programs. Here is its description of colors of hydrogen:
Types of Hydrogen
Hydrogen can be created through a variety of techniques. To distinguish between the different processes, the industry has developed an informal color-based categorization system:
Green hydrogen is created through electrolysis, the process of using electricity to split water (H2O) into hydrogen and oxygen, with renewable energy providing the power for the chemical reaction. No carbon is emitted during the creation of the green hydrogen.
Blue hydrogen is made using natural gas. Through a process called steam reforming, the natural gas and steam combine to create hydrogen and carbon dioxide as a by-product. Carbon capture and storage (CCS) then traps and stores the carbon, creating hydrogen through a carbon-neutral process.
Grey hydrogen is currently the most common mode of hydrogen production. Grey hydrogen is created using steam methane reformation but without capturing the greenhouse gases produced during the process.
Pink hydrogen is generated through electrolysis powered by nuclear energy. Because this process is less common, the industry has not coalesced around a name; nuclear-power hydrogen is also referred to as purple or red hydrogen.
Turquoise hydrogen is produced from methane pyrolysis, in which methane (CH4) is split into hydrogen and solid carbon using heat in reactors or blast furnaces. Turquoise hydrogen is in the early stages of commercialization, and can be more or less carbon intensive depending on the source of energy powering the pyrolysis.
A lot for us old oil and gas lawyers to learn.