Paper contribution

Cyclic thermal treatment of a sandstone from the Upper Rhine Graben

Katharina Meta Neumann; Mandy Duda; Tobias Backers

Proceedings
EUROCK 2026
Pages
427-433
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

The share of renewable energy in overall electric energy production is continuously increasing. Renewable energy provision is in parts subject to seasonal and daily fluctuations (solar and wind). In 2025, electricity generation in Germany therefore exceeded consumption on 80+ days. Energy storage concepts are required to minimize this energy loss. Thermal energy storage systems are a key element of an effective storage strategy accelerating the energy transition. Subsurface storage systems in rock mass are particularly interesting because of their abundant availability, and the suitable thermophysical properties of the material. Changes of the mechanical, thermal, and hydraulic properties upon repeated heating and cooling were investigated to evaluate the impact of the maximum temperature and number of loading cycles on the thermal energy storage medium. A sandstone from the Upper Rhine Graben was selected and heated to maximum temperatures of 200 °C to 600 °C. One cycle comprised heating the specimen to the target temperature in a muffle oven with a rate of ~ 10 to 11.5 °C/min and cooling to 100 °C with an average rate of ~ 0.5 to 1 °C/min. Further specimens were heated between 100 °C and 200 °C for up to 49 cycles. Before and after thermal treatment density, porosity, P-wave velocity, thermal conductivity, permeability, uniaxial compressive strength and triaxial compressive strength were determined. Repeated heating to 200 °C in 49 cycles didn’t cause significant changes in most rock properties; only P-wave velocity showed a significant decrease in comparison to 1 cycle and the reference sample before heating. With increasing maximum temperature, density and P-wave velocity decreased, and effective porosity increased. The most drastic differences were determined for the specimen heated to 600 °C, which can presumably be traced back to the α- to β-quartz transition.

Contributors

Authors

  1. Katharina Meta Neumann Ruhr University Bochum, Germany
  2. Mandy Duda Ruhr University Bochum, Germany
  3. Tobias Backers Ruhr University Bochum, Germany

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References

  1. ASTM D7984-16 (2016) Standard test method for measurement of thermal effusivity of fabrics using a modified transient plane source (mtps) instrument
  2. Becattini V, Motmans T, ZapponeA, Madonna C, Haselbacher A, Steinfeld A (2017) Experimental investigation
  3. of the thermal and mechanical stability of rocks for high-temperature thermal-energy storage. AppliedEnergy203: 373–389.https://doi.org/10.1016/j.apenergy.2017.06.025.
  4. Bundesnetzagentur (2026) SMARD - Strom- und Gasmarktdaten.https://www.smard.de. Accessed at 11.02.2026
  5. DIN EN ISO 17892-3 (2015) Geotechnische Erkundung und Untersuchung - Laborversuche an Bodenproben - Teil 3: Bestimmung der Korndichte
  6. Erneuerbare-Energien-Gesetz - EEG (2023)
  7. Fry N, Adebayo P, Tian R, Shor R, Mwesigye A (2024) A review of district energy technology with subsurface thermal storage integration. GeothermalEnergy12(1): 29. https://doi.org/10.1186/s40517-024-00308-3.
  8. Hao J, Qiao L, Liu Z, Li Q (2022) Effect of thermal treatment on physical and mechanical properties of sandstone for thermal energy storage: a comprehensive experimental study. ActaGeotechnica,17(9): 3887-3908. https://doi.org/10.1007/s11440-022-01514-8.
  9. Harris A, Kazachenko S, Bateman R, Nickerson J, Emanuel M (2014) Measuring the thermal conductivity of heat transfer fluids via the modified transient plane source (mtps) JournalofThermalAnalysisandCalorimetry116: 1309-1314.
  10. Hou P, Gao L, Xing Y, ZhangZP (2020). Effect of thermal cycling on mechanical properties and energy evolution of sandstone. ThermalScience24(6 Part B): 4001-4009. https://doi.org/10.2298/TSCI2006001H.
  11. ISRM (1978) Suggested methods for determining tensile strength of rock materials part 2: suggested method for determining indirect tensile strength by the brazil test. InternationalJournalofRockMechanicsandMiningSciences15 (3): 99–103
  12. ISRM (1978) Suggested methods for determining the strength of rock materials in triaxial compression. InternationalJournalofRockMechanicsandMiningSciences15 (2): 47-51
  13. ISRM (1979) Suggested methods for determining the uniaxial compressive strength and deformability of rock materials: part 1. suggested method for determining deformability of rock materials in uniaxial compression. InternationalJournalofRockMechanicsandMiningSciences16 (2): 138-140.
  14. Jiang Y, Su H, Zhang L, Yu L, Chen G (2023). Heating-path dependency of fracture behavior of sandstone subjected to thermal treatment. TheoreticalandAppliedFractureMechanics127 104096. https://doi.org/10.1016/j.tafmec.2023.104096.
  15. Jing X, Sun Q, Jia H, Ge Z, Wang T (2021). Influence of high-temperature thermal cycles on the pore structure of red sandstone. BulletinofEngineeringGeologyandtheEnvironment80(10): 7817-7830. https://doi.org/10.1007/s10064-021-02389-x.
  16. Khatod KJ, Katekar VP, Deshmukh SS (2022) An evaluation for the optimal sensible heat storage material for maximizing solar still productivity: A state-of-the-art review. JournalofEnergyStorage50 (104622). https://doi.org/10.1016/j.est.2022.104622.
  17. Li M, and Liu X (2022) Effect of Thermal Treatment on the Physical and Mechanical Properties of Sandstone: Insights from Experiments and Simulations. RockMechanicsandRockEngineering55(6): 3171-3194. https://doi.org/10.1007/s00603-022-02791-1.
  18. Li X, Peng J, Xie Y, Li Q, Zhou T, Wang J, Zheng W (2022) Influence of High-Temperature Treatment on Strength and Failure Behaviors of a Quartz-Rich Sandstone under True Triaxial Condition. Lithosphere2022(Special 10). https://doi.org/10.2113/2022/3086647.
  19. Liu X, Lu W, Li M, Zeng N, Li T (2020) The Thermal Effect on the Physical Properties and Corresponding Permeability Evolution of the Heat-Treated Sandstones. Geofluids 2020: 1-16. https://doi.org/10.1155/2020/8838325.
  20. Sun Q, Lü C, Cao L, Li W, Geng J, Zhang W (2016) Thermal Properties of Sandstone After Treatment at High Temperature. InternationalJournalofRockMechanicsandMiningSciences85: 60-66. https://doi.org/10.1016/j.ijrmms.2016.03.006.
  21. Tawalbeh M, Khan HA, Al-Othman A, Almomani F, Ajith S (2023) A comprehensive review on the recent advances in materials for thermal energy storage applications. InternationalJournalofThermofluids18 (100326). https://doi.org/10.1016/j.ijft.2023.100326.
  22. Tiskatine R, Bougdour N, Idoum A, Bazgaou A, Oaddi R, Ihlal A, Aharoune A (2023) Experimental investigation on rock thermal properties under the influence of temperature. Thermochimica Acta720 179424. https://doi.org/10.1016/j.tca.2022.179424
  23. Vidana Pathiranagei S, and Gratchev I (2021) Engineering properties of sandstone heated to a range of high temperatures. BulletinofEngineeringGeologyandtheEnvironment80(3): 2415-2432. https://doi.org/10.1007/s10064-020-02065-6.
  24. Wang M, Li J, Tan H, Wang J, Shi Z, Li K (2023) Study on fatigue characteristics and thermal damage mechanism of red sandstone under high temperature-cyclic load coupling. InternationalJournalofFatigue,168 (107405). https://doi.org/10.1016/j.ijfatigue.2022.107405.
  25. Yang SQ, Xu P, Li YB, Huang YH (2017) Experimental investigation on triaxial mechanical and permeability behavior of sandstone after exposure to different high temperature treatments. Geothermics69: 93-109. https://doi.org/10.1016/j.geothermics.2017.04.009.
  26. Zhao Y, Du C, Bi J, Li J, Wang C (2022) Influence of multiple porous structure evolution on physical–mechanical properties and damage mechanism of sandstone heated continuously/periodically with the identical heating time. BulletinofEngineeringGeologyandtheEnvironment81(12): 507. https://doi.org/10.1007/s10064-022-03020-3.