‘Massive spring’ of almost-pure natural hydrogen found in Albanian mine, emitting at least 200 tonnes of H2 a year
A “massive spring” of almost pure natural hydrogen has been found at the bottom of an underground chromium-ore mine in Albania, raising hopes that naturally occurring H2 could be commercially exploited at low cost around the world.
It had long been known that hydrogen had been leaking into the Bulqizë mine — one of the world’s largest sources of the chromium that is required for stainless steel — following three major explosions since 1992, including one that was fatal.
But the quantity and purity of the hydrogen found in the mine had never been measured until now.
Researchers found a small pool of hot water almost 1km underground that H2-rich gas was constantly bubbling into, which could easily be captured and measured.
They discovered that “the jacuzzi”, as they named it, was pumping out 11 tonnes of 84%-pure hydrogen per year, but based on air samples in other shafts and caverns, they calculated that the mine as a whole was releasing about 200 tonnes of H2 annually, and had been doing so for at least the past six years.
That was 1,000 times higher than the hydrogen being released at geologically similar sites — where pieces of iron-rich oceanic tectonic plates (also known as the upper mantle) have been thrust on top of continental plates to leave behind section known as “ophiolites” — elsewhere in the world, such as Oman.
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France’s National Centre for Scientific Research, CNRS, which was involved in the research, described it as “the highest natural flow of H2 measured to date”.
‘A game-changer’
The finding has led to hopes that naturally occurring hydrogen — also known as white or gold H2 — may be more common than previously expected.
“If you look for it, you’ll find it,” University of Texas energy systems researcher Michael Webber told Science magazine, which has today published an article about what it describes as a “massive spring of hydrogen”.
“It could really disrupt geopolitics, and in many good ways, because the hydrogen will be where the oil and gas are not.”
According to CNRS: “This discovery lays the foundation for new models for the exploration of natural hydrogen.
“Ophiolite massifs, geological formations originating from the oceanic crust and transported to the continents by plate tectonics, are proving to be potential hosts for these high-quality hydrogen reservoirs. These important geological formations spread across Earth have already been identified as hosting hyperalkaline sources where hydrogen bubbles.”
Frieder Klein, a geochemist at the Woods Hole Oceanographic Institution in Massachusetts, told Science that ophiolite formations around the world would be good places to look for natural hydrogen.
“Because there are numerous outcrops of such rocks around the globe… we should really be checking out each and every one of those deposits and then see if there is a similar outgassing of hydrogen that we can possible mine.”
CNRS added: “Historically, ophiolites have not been the subject of exploration campaigns by the oil and gas industry because they were not of interest in terms of hydrocarbon resources. In many ways, this discovery could be a game-changer in our relentless search for energy resources.”
However, Laurent Truche, a geochemist at Grenoble Alps University in France who was involved in the measurements at the Albanian site, believes that the total reservoir of H2 (a trapped pocket of gas) under the mine might hold only 5,000 to 50,000 tonnes of hydrogen, which is probably not large enough for commercial exploitation.
When the US Department of Energy announced that it had made $20m of grant funding available for technologies to measure and exploit natural hydrogen, it recommended that prospectors aim for deposits of ten million tonnes or more.
Nevertheless, Truche added that the H2 could be captured and used for on-site power production.
“For the moment [mine managers] are trying to get rid of hydrogen,” he told Science. “In fact, it may be possible to collect this hydrogen and use it in a gas turbine.”
Is natural hydrogen renewable?
And CNRS added: “It is still too early to say whether natural hydrogen will take a significant place in our energy mix, or remain a niche curiosity. We also point out that natural hydrogen is not a renewable resource, in the sense that production rates are far too slow compared to the world’s energy needs. In addition, these geological environments are often home to a deep and fragile biosphere that proliferates thanks in part to the presence of hydrogen.
“We therefore also deliver a message of caution and invite in-depth reflection on the potential environmental impacts of any future exploration.
“This discovery could redefine our approach to energy resources and opens up exciting prospects for the exploration of natural hydrogen. However, it is essential to continue research taking into account the environmental impact and sustainability of these initiatives.”
Others disagree with CNRS about whether natural hydrogen is a renewable resource.
Analysis of so-called “fairy circles” — depressions on the Earth’s surface with little vegetation associated with seepage of H2 — indicates that these sites alone produce 23 million tonnes a year, not accounting for additional underground reservoirs of hydrogen.
And given the high amount of hydrogen seeping from fairy circles and the constant pressure from the drilling site in Mali, researchers suggest that these stores of hydrogen may be being actively replenished, rather than a static resource that will be depleted over time.
Companies such as Hyterra and Natural Hydrogen Energy are already drilling for H2 in Nebraska and Kansas, while in July last year, Denver-based start-up Koloma raised $91m in funds, including from billionaire Bill Gates-founded Breakthrough Energy, to tap into these resources.
Outside the US, South Australia has seen a recent boom in start-ups prospecting sites around Kangaroo Island and the Yorke and Eyre peninsulas, which have historically seen high quantities of hydrogen gas when drilling for oil.
And in France, four companies have applied for exploration permits for natural H2 since mining regulations were expanded last year to include this molecule.
There are six known ways in which hydrogen is produced naturally:
Serpentinisation
In which the mineral olivine located in mid-ocean ridges or ophiolites (a geological formation where sections of the Earth’s mantle rise above sea level) is weathered to form hydrogen-rich fluids. This has been seen in the Semail ophiolite, in the Hajar Mountains of Oman. Under pressure and high tempertures, water can react with these iron-rich rocks to produce H2.
Radiolysis of water
Radioactive elements in the Earth’s crust — for example in crystalline basement rocks with high content of uranium, thorium or potassium — decompose water molecules trapped in causing a hydrogen pocket, as happened in South Australia.
Deep degassing
In which “primary” hydrogen (a single hydrogen atom attached to a single carbon atom) escapes from deep within the Earth’s crust. This has been seen in Nebraska, in the US.
Iron reduction and sulphur oxidation
Ferric iron in a black smoker (a subsea hydrothermal vent formed from iron sulphide deposits) is reduced to ferrous iron and hydrogen sulphides.
Thermal decomposition of organic matter
In which ammonium compounds located in deep sendiments decompose under high temperatures to form hydrogen and nitrogen, for example in hydrogen-nitrogen gas seeps in Oman.
Biological activity
Hydrogen is produced by microbes living in the Earth’s crusts, usually co-existing with hydrogen-consuming microbes and found via sediment or aquifers. This has been observed in the coal beds of the Powder River Basin in Montana, US.
Source: Rystad Energy
