5 · Depending on production methods, hydrogen can be grey, blue or green – and sometimes even pink, yellow or turquoise – although naming conventions can vary across countries and over time.
The main goal of this study is to describe several methods of producing hydrogen based on the principal energy sources utilized. Moreover, the financial and ecological outcomes of three key hydrogen colors (gray, blue, and green) are discussed.
Gray hydrogen is similar to blue hydrogen. It uses fossil fuels to produce hydrogen through the process of steam reforming. However, unlike blue hydrogen, carbon dioxide (CO2) made during the process is not captured and stored. Instead, CO2 is released into the atmosphere.
There are seven commonly accepted colors of hydrogen: black/brown, gray, green, blue, turquoise, pink, and white. Each color is based on the carbon intensity of the production process or the amount of greenhouse gas emitted for every kilogram of hydrogen produced.
Today, 95 percent of hydrogen produced in the United States is black, brown, or grey hydrogen. For this reason, hydrogen production contributes to 2.2 percent of global emissions. So how could hydrogen possibly help
Grey hydrogen is created from natural gas, or methane, using steam methane reformation but without capturing the greenhouse gases made in the process. Grey hydrogen is essentially the same as blue hydrogen,
Grey hydrogen can be produced inexpensively using coal or natural gas, but it has a significant carbon footprint. Most of the grey hydrogen produced today is made by a process called steam
Grey hydrogen is hydrogen produced using fossil fuels such as natural gas or coal. Grey hydrogen accounts for roughly 95% of the hydrogen produced in the world today. [3] The two main production methods are steam methane reforming and coal gasification. [4]
Gray Hydrogen. Gray hydrogen, the most conventional form sourced from natural gas, is produced through steam methane reforming without carbon capture, resulting in direct CO 2 emissions. This method is cost-effective but contributes to carbon emissions, which poses environmental concerns.
Today, most hydrogen is known as "gray"hydrogen. It''s derived from natural gas using an energy-intensive process that emits a lot of carbon dioxide. "Blue" hydrogen is sometimes touted as a clean alternative.