Yellowstone's geothermal helium: A breakthrough for zero emissions
Scientists have discovered significant reserves of "zero-emission" helium in Yellowstone, which could help address the global scarcity of this gas. Research suggests the possibility of extracting helium without emitting methane.
The Yellowstone region potentially harbours untapped helium reserves that could be used in rockets, reactors, and superconductors without carbon dioxide emissions. Helium is usually a byproduct of natural gas, but scientists are seeking more environmentally friendly sources to mitigate global warming. As a result, they are exploring alternatives in places such as Yellowstone, Tanzania's Rukwa Rift, and Bakreswar-Tantloi in India.
What are the conditions for helium extraction in Yellowstone?
Although scientists have only become aware of Yellowstone's vast helium reserves for over a decade, recent studies on ancient rocks in this region and two other locations are bringing us closer to understanding whether this helium can be extracted. "We are exploring how to find helium free of fossil fuels," said Ernest Mulaya, a geologist from the University of Dar es Salaam in Tanzania, in an interview with "Live Science."
New research, recently published in the "International Geology Review", focuses on regions that emit concentrated helium without accompanying methane emissions. While helium is typically a byproduct of natural gas, scientists are searching for more ecological sources to combat global warming. "If the temperature rises above the closure temperature of a given mineral, then helium will be released," explained Jon Gluyas, a professor at Durham University, UK.
Could Yellowstone be a source of "green" helium?
The research suggests that Yellowstone, like Bakreswar-Tantloi in eastern India and Rukwa Rift in southwestern Tanzania, is geothermally active. This means that heat from the Earth's interior reaches the surface, leading to the formation of geysers and hot springs. Geothermal heat is essential for helium production without carbon emissions because it releases helium atoms from deep rocks. Helium is formed from the decay of uranium and thorium, which takes billions of years. These atoms remain trapped in crystals within the rocks unless exposed to high temperatures.
Jon Gluyas, a professor of geoenergy, carbon capture, and storage at Durham University, UK, explained on the "Live Science" portal that if the temperature exceeds the so-called closure temperature of a given mineral, helium will be released. Helium then enters fluids like water or brine that flow between rocks, forming a gas that can migrate underground and rise to the Earth's surface.
The discovery of helium in Tanzania in 2016 raised hopes that similar geological conditions might exist elsewhere and also harbour helium reserves free of carbon emissions. Besides geothermal activity, Rukwa Rift sits on rocks that are billions of years old and rich in uranium and thorium, meaning helium has had sufficient time to form.
Helium essential for cooling, among others, in rockets or reactors
It turns out that Yellowstone also sits on ancient, helium-producing rocks. Yellowstone is rooted in the Wyoming craton, which contains rocks around 3.5 billion years old, and the faults at the edges of the caldera likely create channels for significant amounts of helium.
However, it is unlikely that there is a closed reservoir beneath Yellowstone, as Gluyas explained. Instead, the national park creates a system of channels through which helium escapes into the atmosphere: approximately 66 metric tonnes of helium leak annually through hot springs and steam vents, as scientists revealed in 2014. Helium is a crucial cooling element in rockets, nuclear reactors, superconductors, and diagnostic equipment, but suppliers may soon struggle to meet growing demand.
Every year, approximately 66 tonnes of helium leak through the hot springs in Yellowstone
The main findings of the new study are that all three locations have very promising conditions, warranting further research. Results from the helium drilling site near Babbitt suggest that helium production without carbon emissions is possible, and the concentration of helium in the extracted gas could be very high. Mulaya emphasised that the future of helium is promising to address current shortages.
