This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Deep beneath parts of Western Australia, injecting CO2-rich water into iron-rich rocks may offer an unexpected opportunity for both clean energy production and carbon storage. New CSIRO research published in the International Journal of Hydrogen Energy investigated the potential of orange hydrogen in the Yilgarn Craton, one of Australia's oldest and best-preserved geological regions.
Led by Energy Research Scientist Dr. Lingping Zeng, the research explored the double advantage of iron-rich rocks. "Orange hydrogen uses a naturally occurring geological process called serpentinization but stimulates it by injecting CO2-saturated water into iron-rich rocks underground," said Zeng.
"Put simply, serpentinization is when water interacts with iron-bearing minerals in these rocks, the iron is oxidized, and hydrogen gas is produced. In an orange hydrogen system, this water-rock reaction is deliberately stimulated to enhance hydrogen generation. The 'orange' name refers to the oxidized iron involved in the process underground." Australia is particularly well-positioned to investigate this opportunity because large areas of the continent contain the types of rocks needed for these reactions.
The Yilgarn Craton, stretching across south-central Western Australia and named after a local Indigenous word meaning "white stone" or "quartz," is one such region. This geological block has survived eons of tectonic movements largely intact and contains some of Earth's oldest crust—including zircon crystals dating back more than 4 billion years. Forming the geological foundation of much of Western Australia today, it contains extensive deposits of iron-rich and magnesium-rich rocks that may be suitable for stimulated hydrogen generation.
Regina Sander, an experimental reservoir engineer and techno-economic modeler, said what makes orange hydrogen especially interesting is that the same rocks capable of producing hydrogen can also help address another challenge: storing carbon dioxide. "When carbon dioxide dissolved in water flows through these rocks, it can react with minerals and become permanently trapped as solid rock. This process, known as carbon mineralization, converts carbon dioxide into stable carbonate minerals that can remain locked underground.
"This means the same geological system could potentially generate clean hydrogen while also permanently removing carbon dioxide from circulation. "However, the conditions that maximize hydrogen generation are not always the same conditions that maximize carbon storage. Understanding these trade-offs is essential if orange hydrogen is to become a practical energy solution," said Sander.
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