Mahmoud Leila
Ahmed A. Radwan
Mohammad A. Abdelwahhab3
Isabelle Moretti- 1Faculty of Science, Mansoura University, Mansoura, Egypt
- 2Department of Geology, Faculty of Science, Al-Azhar University, Assiut Branch, Assiut, Egypt
- 3Geology Department, Faculty of Science, Al-Azhar University, Cairo, Egypt
- 4Institut des Sciences de la Terre de Paris (ISTeP), Sorbonne Université, Paris, France
- 5Laboratoire des Fluides Complexes et leurs Réservoirs (LFCR)-Université de Pau et des Pays de l’Adour (UPPA), Pau, France
Editorial on the Research Topic
Natural hydrogen in different contexts: geological, cosmochemical, and biological
The di-hydrogen H2 is assuming a growing role in the energy mix, or, more exactly, it is expected to play a key role in the energy transition by the middle of this century. H2 could be seen as an energy vector when it is used to store electricity using the power-to-gas approach. It is also a primary source of energy when we manage to find and produce natural H2 generated in the subsurface. However, there are still some uncertainties about the generation and accumulation of natural H2 in the subsurface, and research is underway to better understand how to explore and store H2. This Research Topic was conceived in this context.
Today, the list of H2-generating rocks has started to become reasonably established. H2 is produced naturally from water through oxido-reduction or radiolysis (Larin et al., 2015; Truche et al., 2020; Leila et al., 2022). Another alternative is the late maturation of organic matter (Horsfield et al., 2022). Some authors suggest a long list of favorable settings mixing geological context and reactions, while others propose a more synthesized view with only four H2-generating rock types. However, many questions remain to be answered about the generation mechanisms of natural H2 and about its transport and accumulation in the subsurface. If high-temperature serpentinization has been largely studied (Klein et al., 2009), the significance of oxidation in other iron-rich rocks, such as banded iron formation “BIF,” or biotite-rich rocks is still poorly-explored (Murray et al., 2020; Geymond et al., 2022). The work conducted by Geymond et al. is particularly important in this respect since it demonstrates that the concept of high-temperature conditions for rapid redox reactions is not at all necessary. The magnetite produced during redox reactions generates a large quantity of H2 at 80°C. This has implications for BIF oxidation and also for ophiolites.
Since E&P is just starting up, there are still little data available, and the companies that acquire these data are not always willing to release them to the public. The work conducted by Lévy et al. on gas springs in the Dinarides shows the heterogeneity of H2 content at the scale of an ophiolitic nappe and provides guidelines to focus on the most prospective zones.
The occurrence of subcircular depressions with vegetation anomalies, also informally called fairy circles, has demonstrated its worth for a long time as indications for subsurface hydrogen seepage; first in Russia and then in the United States and Brazil. Its systematic use in conjunction with satellite data to select prospective areas has been proposed by Moretti et al. (2021a, b), Moretti et al. (2022) for the Australian and Namibian H2-rich provinces. However, not all depressions are related to H2 emanations. In desert areas where salt pans may have a similar morphology, Aimar et al. have aimed to discriminate between these features based on a case study in the southwest Australian craton.
The biosphere is also known to impact H2 generation and consumption. The fact that the biosphere can have a positive effect on the creation of H2 accumulation is debated; the consumption of this gas is not in doubt. Warr et al., using data from the Kidd Creek observatory—an almost 3 km-deep mine—to study the deep biosphere in Canada, propose a quantitative approach through Monte Carlo modeling to understand the cycle of H2 and other gases, such as helium and argon, in the first kilometers.
Similarly to the generation and accumulation of H2, its storage is also a complicated task due to its small size and high diffusivity. Moreover, a wide-scale implementation of a H2-based economy requires a medium giga-to-tera-scale storage capacity, which requires specific geological conditions to effectively store H2 in the subsurface. Alanazi et al. investigated the capability of Saudi basalt to store H2 in underlying clastic depleted reservoirs based on an evaluation of the wettability of the basalt/H2/brine system of two basalt samples from Harrat Uwayrid, a Cenozoic volcanic field in Saudi Arabia.
The exploration of H2 has begun, and we hope that these articles will enable everyone to take part.
Author contributions
ML: Conceptualization, Investigation, Writing–original draft, Writing–review and editing. AR: Investigation, Writing–review and editing. MA: Investigation, Writing–review and editing. IM: Conceptualization, Investigation, Supervision, Writing–original draft, Writing–review and editing.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
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References
Geymond, U., Ramanaidou, E., Lévy, D., Ouaya, A., and Moretti, I. (2022). Can weathering of Banded Iron Formations generate natural hydrogen? Evidences from Australia, Brazil and South Africa. Minerals 12, 163. doi:10.3390/min12020163
Horsfield, B., Mahlstedt, N., Weniger, P., Misch, D., Vranjes-Wessely, S., Han, S., et al. (2022). Molecular hydrogen from organic sources in the deep Songliao Basin, PR China. Int. J.Hydrog. Energy 47 (38), 16750–16774. doi:10.1016/j.ijhydene.2022.02.208
Klein, F., Bach, W., Jöns, N., McCollom, T., Moskowitz, B., and Berquó, T. (2009). Iron partitioning and hydrogen generation during serpentinization of abyssal peridotites from 15°N on the Mid-Atlantic Ridge. Geochimica Cosmochimica Acta 73 (22), 6868–6893. doi:10.1016/j.gca.2009.08.021
Larin, N., Zgonnik, V., Rodina, S., Deville, E., Prinzhofer, A., and Larin, V. N. (2015). ‘Natural molecular hydrogen seepage associated with surficial, rounded depressions on the European craton in Russia. Nat. Resour. Res. 24 (3), 369–383. doi:10.1007/s11053-014-9257-5
Leila, M., Loisseau, K., and Moretti, I. (2022). Controls on generation and accumulation of blended gases (CH4/H2/He) in the Neoproterozoic Amadeus Basin, Australia. Mar. Petroleum Geol. 140, 105643. doi:10.1016/j.marpetgeo.2022.105643
Moretti, I., Brouilly, E., Loiseau, K., Prinzhofer, A., and Deville, E. (2021a). Hydrogen emanations in intracratonic areas: new guide lines for early exploration basin screening. Geosciences 11 (3), 145. doi:10.3390/geosciences11030145
Moretti, I., Geymond, U., Pasquet, G., Aimar, L., and Rabaute, A. (2022). Natural hydrogen emanations in Namibia: field acquisition and vegetation indexes from multispectral satellite image analysis. Int. J.Hydrog. Energy 47 (84), 35588–35607. doi:10.1016/j.ijhydene.2022.08.135
Moretti, I., Prinzhofer, A., Françolin, J., Pacheco, C., Rosanne, M., Rupin, F., et al. (2021b). Long-term monitoring of natural hydrogen superficial emissions in a brazilian cratonic environment. Sporadic large pulses versus daily periodic emissions. Int. J.Hydrog. Energy 46 (5), 3615–3628. doi:10.1016/j.ijhydene.2020.11.026
Murray, J., Clément, A., Frita, B., Schmittbuhlc, J., Bordmannd, V., and Fleury, J. M. (2020). Abiotic hydrogen generation from biotite-rich granite: a case study of the Soultz-sous-Forets geothermal site. Appl. Geochem. 119, 1–15. doi:10.1016/j.apgeochem.2020.104631
Keywords: natural hydrogen, hydrogen generating rock types, hydrogen storage, low-temperature redox reactions, fairy circles
Citation: Leila M, Radwan AA, Abdelwahhab MA and Moretti I (2023) Editorial: Natural hydrogen in different contexts: geological, cosmochemical, and biological. Front. Earth Sci. 11:1296646. doi: 10.3389/feart.2023.1296646
Received: 18 September 2023; Accepted: 29 September 2023;
Published: 12 October 2023.
Edited and reviewed by:
Martyn Tranter, Aarhus University, DenmarkCopyright © 2023 Leila, Radwan, Abdelwahhab and Moretti. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Mahmoud Leila, mahmoud_lotfy@mans.edu.eg