In the 1990s, geochemist Barbara Sherwood Lollar and her team embarked on a groundbreaking expedition into the Kidd Creek mine in northern Ontario. Delving more than three kilometers deep into one of North America’s ancient geological formations, they discovered water that had remained isolated for over a billion years. This ancient brine was not just a relic of the past; it served as a habitat for microorganisms that thrive on hydrogen produced through chemical interactions between the water and surrounding rocks.
Fast forward to today, Sherwood Lollar, now affiliated with the University of Toronto, has revisited the hydrogen data from the mine, aiming to assess whether it could serve as a viable source of zero-carbon fuel. “If we can engage innovative minds to effectively harness this resource, it could significantly contribute to the emerging hydrogen economy,” she remarks. While hydrogen fuel presents a promising avenue for sustainable energy, conventional production methods often result in high greenhouse gas emissions and consume more energy than the gas provides. However, tapping into natural underground reservoirs—termed “geologic hydrogen”—could transform this scenario.
Recent exploration initiatives have been launched globally to locate these reservoirs, generated when water molecules react chemically with iron-rich rocks or through radioactive decay. Companies such as Australia’s HyTerra and the Bill Gates-affiliated Koloma are investigating ancient oceanic formations in the U.S. Midwest for potential hydrogen yields. Researchers from the U.S. Geological Survey estimate that the Earth’s crust generates trillions of tons of hydrogen; if a fraction of this could be extracted, it might satisfy global hydrogen needs for centuries. However, despite extensive exploration, no commercially viable hydrogen reservoirs have been confirmed, leaving public data scarce as companies compete for investment.
At Kidd Creek, Sherwood Lollar and her colleague Oliver Warr meticulously analyzed over a decade’s worth of data from 35 boreholes, revealing that each borehole emits an average of eight kilograms of hydrogen annually. Extrapolating this finding to the mine’s 14,000 boreholes suggests that approximately 140 metric tons of hydrogen escape unused each year. While this quantity may not seem transformative, if captured, it could provide a significant energy source for the mine’s operations, demonstrating the practical utility of geologic hydrogen.
These findings align with growing evidence that natural hydrogen formation is a legitimate geological process. Laurent Truche, a geochemist from the University of Grenoble Alpes, noted that his research indicated around 200 metric tons of hydrogen flow from the Bulqizë chromium mine in Albania annually. The ongoing challenge, he emphasizes, lies not in proving hydrogen’s existence but in demonstrating its economic and reliable large-scale production.
Research teams are also exploring methods to enhance hydrogen production by injecting water, heat, or catalysts into reactive rocks. More than a dozen projects supported by ARPA-E are focused on significantly accelerating hydrogen production rates to achieve commercial viability. A recent project in Oman exemplified this potential; after drilling a one-kilometer borehole and injecting substantial water, researchers found gas that was 90% hydrogen emerging from the well. While this initial success is promising, it raises critical questions about whether the hydrogen was stimulated or naturally occurring.
Source: How much hydrogen awaits us underground? via MIT Technology Review