MV#9 — The Hunt for H2 — Rūta Karolytė

For many years scientific consensus has averred that hydrogen does not occur naturally in significant quantities without being bound to other atoms (such as in H20, water, or CH4, methane). To obtain the gas — whether as a fuel or for use in fertilizers — we need to strip it from those molecules — typically by electrolysis and steam reformation. But our understanding may be ripe for change.

Website of National Renewable Energy Laboratory from February 2023, following the publication of a New York Times article on natural H2, the text was changed to “Because hydrogen typically does not exist freely in nature” (emphasis mine)

Rūta Karolytė is at the vanguard of prospectors looking for large, naturally occurring reservoirs of hydrogen. She’s a researcher from Oxford specializing in the geochemistry of the Earth and she enlightens us to the mechanisms that are likely to be producing hydrogen in the crust: radiolysis and serpentinization. 

In reviewing the evidence for naturally occurring hydrogen we pass through exotic terrain: a Soviet-era theory of hydrocarbon production, fairy rings, hydrothermal vents and chemosynthetic life. These organisms, remarkably, do not depend on the sun, plants, or any other life forms for their energy. Instead, they draw directly from the power stored in inorganic compounds. Their existence is testimony to the natural occurrence of hydrogen.

This does not guarantee that hydrogen is present in large quantities, but modeling of the processes that produce it — particularly serpentinization — suggests it is. Serpentinization is a kind of rusting whereby rocks are oxidized and hydrogen is freed from water molecules, wherever water and the right kinds of rocks are present and the pressure and temperature are right, hydrogen will be produced. What is more this process could be sped up by the introduction of more water underground.

If Rūta and her fellow prospectors are correct, the tapping of natural hydrogen could have transformative consequences for the “Hydrogen economy” — such as cutting out the substantial fossil fuel emissions associated with deriving fertilizers from methane or creating a cheap basis for building synthetic fuels.

In the first half of the show, we also delve into carbon sequestration — another cool climate topic. But I’ve got so excited writing up the first half, that I’ll leave it here.