Mimicking natural hydrogen | 'Geologic H2 can be artificially produced underground by stimulating iron-rich rock'
US senators told that Bill Gates-backed start-up is already ‘doing it today in our lab’
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“This works,” he said. “We’re doing it today in our lab.”
But Johnson was clear that process of artificially stimulating iron ore to produce hydrogen might not be commercially viable.
“The big question is: Can you produce enough gas quickly enough out of a well for the economics to work? The science of it is real. It’ll probably take five to seven years for us to really know if that works.”
Johnson did admit, however, that “we’re pretty far away from conceptualising what that [stimulated] system would look like”.
ARPA-E director Dr Evelyn Wang told the hearing on natural hydrogen that the underground rock stimulation could be as simple as “introducing high-pressure steam into the subsurface with these iron-rich rocks”, which she later confirmed could include commercial iron ore.
“And that could be an avenue for us to pursue moving forward, in addition to the natural hydrogen that is potentially all around the world.”
Wang had previously told the hearing in her opening statement: “While simply extracting the current supply of naturally accumulating hydrogen, in and of itself, can enhance the US energy economy, ARPA-E is committing research support to explore a potentially disruptive step in the process.
“Through understanding how we can artificially stimulate these deposits, there is a theoretical potential to produce enough clean hydrogen to impact US energy demand.”
She explained that ARPA-E had handed out almost $14m of grants in early February to identify the technologies that could perform this artificial production of geologic hydrogen and develop “an understanding of controlling these hydrogen-producing geochemical reactions”.
Wang also pointed that a further $7.2m had also been handed out by ARPA-E in early February for “technologies relevant to the management and extraction of hydrogen from geologic reservoirs, this includes how we can contain and transport this source of energy from the Earth’s subsurface, and mitigate risks associated with these efforts”.
Key natural hydrogen production processes, environments and locations
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 temperatures, 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.