Under normal conditions of temperature and pressure, hydrogen gas has no visible color. However, in specific contexts, notably in industrial applications, color codes are used to indicate its origin. To obtain a usable fuel, hydrogen must be subjected to different processes to separate it from other elements. This is done by the decomposition of water molecules (H₂O) or methane (CH₄).
Among the different variants, green hydrogen stands out as the most sustainable. It is obtained by using excess energy for the electrolysis of water from renewable sources such as wind and solar energy. It currently represents less than 1% of total hydrogen production, according to the International Energy Agency (IEA). A Japanese company has chosen to use methane to produce hydrogen from methane: turquoise hydrogen.
What is hydrogen turquoise and why is it so important?
Turquoise hydrogen is produced from methane in natural gas and biogas through a decomposition process called molten metal pyrolysis. During this process, natural gas passes through the molten metal, releasing hydrogen and solid carbon, helping to avoid polluting CO2 emissions.
Japanese industrial machinery maker Ebara, which makes pumps and other equipment for hydrogen systems, is developing a new method for producing turquoise hydrogen. It aims to commercialize it around 2026, taking advantage of the global trend toward decarbonization.
The current turquoise hydrogen production process extracts both hydrogen and carbon in a single reactor. However, Ebara intends to extract them separately to obtain different types of solid carbon without affecting hydrogen production. Solid carbon has multiple applications, from reinforcing tires with carbon black to using carbon fiber in cars and airplanes.
This type of hydrogen may have some advantages over those that are considered more environmentally friendly. The production of green hydrogen, generated from renewable energy sources, or blue hydrogen, which involves the extraction of fossil fuels and uses carbon capture and storage technology to mitigate carbon dioxide emissions , is expensive due to the amount of energy required. Additionally, the difficulty of setting up the necessary carbon storage facilities remains an obstacle for blue hydrogen.
This is why turquoise hydrogen has been touted as a cheaper solution to produce a carbon-free fuel, depending on the source of electricity used in the methane heating process.
In 2022, Ebara launched this commercial hydrogen project, supervised directly by the company’s president. The company sees turquoise hydrogen as essential to its goal of contributing to a “sustainable society.” The Tokyo-based company has established collaborations with the National Institute of Materials Science, Shizuoka University and materials manufacturer Taiyo Koko. The project was commissioned by the New Energy and Industrial Technology Development Organization, supported by the Japanese government.