Researchers from the GeoRessources Laboratory at the University of Lorraine and the CNRS stumbled upon something extraordinary while probing the region’s subsoil. What they found could potentially be the largest deposit of natural hydrogen on Earth, heralding a new era in the quest for sustainable energy.
The journey to this groundbreaking revelation began with a different goal altogether. The team’s initial objective was to assess the presence of methane in Lorraine’s subsoil—a resource that, if abundant, could have facilitated local methane production. To achieve this, they devised innovative technologies, including the SysMoG probe, capable of continuous, in-situ monitoring of geological formations, even at depths of up to 1,200 meters. Little did they know that their quest for methane would unveil something far more profound.
As they monitored the geological strata and the gases accompanying methane, they made a startling observation—hydrogen was not only present but was increasing in concentration with depth, reaching a remarkable 20% at 1,250 meters below the surface. Mathematical models now suggest that at a staggering depth of 3,000 meters, hydrogen levels could surpass 90%. This discovery hinted at the presence of an unparalleled deposit of white hydrogen, the primary form of hydrogen found naturally, unlike its gray or green counterparts produced from other sources.
But what exactly is white hydrogen, and why is this discovery so significant? Hydrogen, in its various forms, plays a pivotal role in the clean energy transition. Gray hydrogen is produced by transforming natural gas, a process criticized for its carbon emissions. In contrast, green hydrogen is produced through water electrolysis using renewable energy, making it a carbon-free energy source. White hydrogen, the focus of this discovery, is hydrogen already present in its natural state. This inherent availability without the need for energy-intensive production processes makes it a compelling resource for replacing fossil fuels in transport and energy-intensive industries.
The researchers’ favored hypothesis for this hydrogen’s origin in Lorraine involves the interaction of water molecules with minerals rich in iron carbonates. When these compounds meet, they trigger oxidation reactions of minerals and reduction of water, resulting in the production of hydrogen and iron oxides. Importantly, these chemical processes are rapid, occurring within weeks or months, and the reserves of iron carbonate in Lorraine’s subsoil appear almost limitless.
However, before envisioning the utilization of this colossal hydrogen deposit, several crucial steps remain. The first involves confirming the homogeneous presence of hydrogen across the vast basin of 490 square kilometers in Lorraine. To achieve this, the SysMoG probe will be deployed in boreholes near the Folschviller site where hydrogen was discovered. The next critical test involves drilling to the astounding depth of 3,000 meters to validate the hydrogen concentration’s continuous increase at such depths.
Funding from industrial and institutional partners, both domestic and international, is already showing interest in this ambitious project. The researchers’ challenge now lies in persuading the French government of its significance and securing the necessary authorizations. This endeavor will be conducted through the REGALOR II research program, slated to begin in the first quarter of 2024, with a maximum duration of 3 to 4 years—making the prospect of tapping into this immense hydrogen resource not so distant.
The potential implications of this discovery extend beyond its sheer scale. It necessitates a reevaluation of our understanding of natural gas deposits. The gas pressures in this unique deposit are significantly lower than conventional deposits, but its lateral extension is far greater. This calls for innovative extraction techniques, such as separating the gases of interest at the well’s bottom to avoid constructing surface separation units. This approach could also help preserve agricultural land.
While the promise of abundant natural hydrogen is exciting, there are still challenges to address. Hydrogen is flammable and explosive when it forms mixtures exceeding 4% in air. However, in the underground environment of Lorraine’s carboniferous rocks, devoid of oxygen, explosion risks are virtually nonexistent. This fact underscores the importance of preventing contact between hydrogen and surface oxygen in separation and distribution units.
The local enthusiasm for this discovery is palpable, especially among elected officials and communities familiar with Lorraine’s mining history. The potential economic benefits, coupled with the region’s technical expertise, make this journey towards harnessing hydrogen’s power all the more promising. Beyond the borders of France, neighboring regions such as Hauts-de-France and neighboring countries like Luxembourg, Saarland, and Wallonia are showing keen interest.
As Lorraine inches closer to unveiling the full extent of its hidden hydrogen treasure, the world watches with anticipation. This colossal deposit of natural hydrogen, if harnessed effectively, could revolutionize energy production, offering a sustainable alternative to fossil fuels and marking a transformative moment in the global pursuit of a cleaner, greener future.
