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Cited by 8Molten salt chemistry and electrochemical processesMetallurgical Processes and ThermodynamicsPlanetary Science and Exploration

Identifying an efficient endpoint for oxygen extraction from lunar regolith simulant pellets using molten salt electrolysis

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Lomax, Bethany A., Selmeci, Áron, Rützler, Alexander, Schild, Timon, Symes, Mark D., Bonsall, Emily, Schröder, Christian, Conti, Melchiorre +2 more·2025·Acta Astronautica
DOI 10.1016/j.actaastro.2025.04.049
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Abstract

Extracting oxygen and metals from lunar regolith would support exploration activities on the Moon and beyond. This study examines various factors that influence the efficiency and long-term viability of lunar resource extraction processes, specifically focussing on molten salt electrolysis, or the FFC-Cambridge process. Pellets of lunar mare simulant were reduced for a range of different times, to explore the behaviour throughout the extraction process. Experiment sets were carried out with both carbon anodes and oxygen-evolving tin oxide anodes showing that, while the reduction rate was faster with carbon anodes, similar trends in the rate and efficiency of the process could be observed for mare regolith simulant regardless of anode material. Comparative experiments with lunar highland simulant material demonstrated that the process can be used to extract oxygen for both materials, but that an overall higher current efficiency can be achieved for highland regolith material. Analysis of the solid product at different stages throughout the reduction of mare simulant demonstrated the important role of Ca in the molten salt reduction process and highlighted the non-simultaneous nature of the reduction process in a bulk sample. Overall, the results described indicate that targeting 60 % oxygen extraction may afford the most oxygen in the least time, while targeting 70–80 % extraction would maximise power efficiency. However, to maintain a balanced electrolyte and ensure the proce…

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Authors
Lomax, B. A., Selmeci, Á., Rützler, A., Schild, T., Symes, M. D., Bonsall, E., Schröder, C., Conti, M., Lindner, R., & Carpenter, J. D.
Affiliations
  • European Space Agency (FR)
  • University of Luxembourg (LU)
  • University of Glasgow (GB)
  • University of Stirling (GB)
Corresponding author
Lomax, Bethany A.
ORCID
Venue
Acta Astronautica
Publisher
Elsevier BV
Published
2025-09
Volume
234
Pages
287-295
ISSN
0094-5765 (ISSN-L)
DOI
10.1016/j.actaastro.2025.04.049
OpenAlex
W4409726266
Cited by
8
References
5
Citations by year
2026: 5 · 2025: 3
FWCI
2.24
Type
journal article
Language
en
Open access
Licence
Locations
  • Acta Astronautica (publishedVersion, cc-by-nc-nd)
  • ENLIGHTEN (Jurnal Bimbingan dan Konseling Islam) (submittedVersion, cc-by-sa)
Funders
European Space Agency
Topics
  • Physical Sciences › Chemical Engineering › Fluid Flow and Transfer Processes › Molten salt chemistry and electrochemical processes
  • Physical Sciences › Engineering › Mechanical Engineering › Metallurgical Processes and Thermodynamics
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Planetary Science and Exploration
Keywords
lunar regolith simulant, molten salt electrolysis, FFC Cambridge process, carbon anodes, tin oxide anode, current efficiency, reduction kinetics, lunar resource utilization

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