Ugo Geymond
Graduated with a Master’s degree in Geology from Université Paris Cité (UPC), I am currently pursuing my PhD at the Institut de Physique du Globe de Paris (IPGP) and the Institut Français du Pétrole et des énergies nouvelles (IFPen).
The primary goal of my research is to understand the generation of natural hydrogen (H2) related to iron (Fe) oxidation during water-rock interactions. I aim to define the potential of specific lithologies to source H2 within the scope of future exploration programs. My focus is mainly on Banded Iron Formations (BIF), which host vast amounts of reduced Fe, using Western Australian BIF (Archean to Paleoproterozoic) and Namibian BIF (Neoproterozoic) as case studies.
To address this, I employ several complementary tools, including: (1) Water-rock experiments and thermodynamic modeling to constrain the reactivity of Fe-rich minerals and rocks at a fundamental scale. (2) Petrography on core samples, which allows extrapolation of lab results to natural environments. (3) In-field gas measurements and structural geology at suspected H2 occurrences to validate conceptual models of H2 generation, trapping, and migration pathways.
Authors: U. Geymond1,2, O. Sissmann2, A. Vindret2, T. Briolet2, E. Ramanaidou3, I. Moretti4
Corresponding author: geymond@ipgp.fr
1 Institut de physique du globe de Paris, CNRS, Université Paris Cité, Paris, France ;
2 IFP Energies Nouvelles (IFPEN), Rueil-Malmaison, France ;
3 Commonwealth Scientific and Industrial Research Organisation (CSIRO), Kensington, WA 6151, Australia ;
4 Laboratoire des fluides complexes et de leurs réservoirs, CNRS, Université de Pau et des Pays de l’Adour, Pau, France ;
Abstract:
Substantial accumulations of geological hydrogen (H2) are now being tracked worldwide as a potential new, clean energy source for the ecological transition. However, the transportation of hydrogen over long distances presents challenges in both profitability and technology, casting (or raising) doubt on the feasibility of using H2 far from its production site [1]. Similarly, H2 generation through stimulation must be conducted close to energy consumers. At least in the short term, producing H2 for local needs appears to be a more practical solution.
Mining companies face two main daily challenges [2]: (i) reducing their environmental footprint such as by recycling waste, and (ii) supplying energy to their mines, particularly in isolated locations. Combining these concerns, it is tempting to explore geo-inspired H2 generation by using mine tailings to produce a low-carbon and low-cost energy source directly on site.
The desertic Hamersley Province in Western Australia hosts the largest Banded Iron Formations (BIF) deposit in the world, far from common human activities. These Fe-rich rocks from the Precambrian period contain up to 40 wt% Fetotal (mainly FeII) when preserved from surficial alteration, distributed among Fe-oxide, Fe-carbonate, and Fe-silicate [3]. In some locations, BIF underwent significant iron enrichment and oxidation, favoring (or enhancing) their exploitability, which results in numerous assets in the region.
In recent months, a series of experiments was conducted on a BIF sample from a drill core of the Brockman Formation, one of the main Fe-rich horizons in Hamersley [4]. The sample was powdered to mimic mine tailings and reacted with O2 -free water at temperatures between 40°C and 90°C. Isotherms of H2 generation were constructed by monitoring H2 levels in experimental reactors over several days. Results indicate that up to a few mmol/kg of rock can be produced from the starting material, with kinetics highly dependent on temperature. Although further investigation is needed, this study represents a promising first step towards a decarbonized and decentralized energy supply for mining companies, potentially reducing both their energy costs and environmental impact.
[1] Lapi, T., Chatzimpiros, P., Raineau, L., & Prinzhofer, A. (2022). System approach to natural versus manufactured hydrogen: An interdisciplinary perspective on a new primary energy source. International Journal of Hydrogen Energy, 47(51), 21701-21712.
[2] Carvalho, M., Romero, A., Shields, G., & Millar, D. L. (2014). Optimal synthesis of energy supply systems for remote open pit mines. Applied thermal engineering, 64(1-2), 315-330.
[3] Klein, C. (2005). Some Precambrian banded iron-formations (BIFs) from around the world: Their age, geologic setting, mineralogy, metamorphism, geochemistry, and origins. American Mineralogist, 90(10), 1473-1499.
[4] Ewers, W. E., & Morris, R. C. (1981). Studies of the Dales Gorge member of the Brockman iron formation, Western Australia. Economic Geology, 76(7), 1929-1
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