Natural hydrogen

Natural hydrogen (known as white hydrogen, geologic hydrogen or gold hydrogen), is hydrogen that is formed by natural processes (as opposed to hydrogen produced in a laboratory or in industry). By contrast green hydrogen is produced from renewable energy sources, while grey, brown, blue or black hydrogen are obtained from fossil fuels. White hydrogen may be renewable. It is non-polluting and may offer lower costs than industrial hydrogen. Natural hydrogen has been identified in many source rocks in areas beyond the sedimentary basins where oil companies typically operate.

Origins
Sources of natural hydrogen include:


 * degassing of deep hydrogen from Earth's crust and mantle;
 * reaction of water with ultrabasic rocks (serpentinisation);
 * water in contact with reducing agents in Earth's mantle;
 * weathering – water in contact with freshly exposed rock surfaces;
 * decomposition of hydroxyl ions in the structure of minerals;
 * natural water radiolysis;
 * decomposition of organic matter;
 * biological activity

Reserves
According to the Financial Times, there are 5 trillion tons of natural hydrogen reserves worldwide. A discovery in Russia in 2008 suggests the possibility of extracting native hydrogen in geological environments. Reserves have been identified in France, Mali, the United States and approximately a dozen other countries.

An accumulation of natural hydrogen was discovered in a water well in Bourakébougou, Mali, that was exploited to power the nearby village. In 2023 Pironon and de Donato announced the discovery of a deposit they estimated to be some 46 million to 260 million metric tons (several years worth of 2020s production). In 2024, a natural deposit of helium and hydrogen was discovered in Rukwa, Tanzania. , as well in Bulqizë, Albania.

Mid-continent Rift System
White hydrogen could be found or produced in the Mid-continental Rift System at scale. Water could be pumped down to hot iron-rich rock to produce hydrogen for extraction.

Geology
Natural hydrogen is generated from various sources. Many hydrogen emergences have been identified on mid-ocean ridges. Serpentinisation occurs in the oceanic crust.

Diagenetic origin (iron oxidation) in the sedimentary basins of cratons, notably are found in Russia.

Mantle hydrogen and hydrogen from radiolysis (natural electrolysis) or from bacterial activity are under investigation. In France, the Alps and Pyrenees are suitable for exploitation. New Caledonia has hyperalkaline sources that show hydrogen emissions.

Hydrogen is soluble in fresh water, especially at moderate depths as solubility generally increases with pressure. However, at greater depths and pressures, such as within the mantle, the solubility decreases due to the highly assymetric nature of mixtures of hydrogen and water.

Literature
Vladimir Vernadsky originated the concept of natural hydrogen captured by the Earth in the process of formation from the post-nebula cloud. Cosmogonical aspects were anticipated by Fred Hoyle. From 1960–2010, V.N. Larin developed the Primordially Hydridic Earth concept that described deep-seated natural hydrogen prominence and migration paths.