From Biogas to Grid: Co-Electrolysis and Methanation for High-Yield Biomethane
DOI:
https://doi.org/10.52825/isec.v2i.3308Keywords:
Biogas, Biomethane, Renewable Gases, Co-electrolysis, SOEC, Methanation, Defossilisation, Gas Grid, StorageAbstract
This paper presents a concept for increasing biomethane yields from biogas plants by combining solid oxide co-electrolysis with downstream methanation, thereby utilizing biogenic CO₂ instead of releasing it unused. A major opportunity for this concept is provided by Austria’s untapped biomethane potential together with existing gas infrastructure and storage capacities for seasonal balancing of renewable gases. A distribution grid case study illustrates how biomethane injection can exceed local demand during periods of low consumption, leading to indirect utilization via recompression, transfer, or storage, while winter demand enables higher direct substitution of fossil gas. To evaluate integration options, a modular system-level simulation framework is developed, linking detailed single-cell SOEC electrochemistry, mass transport, and thermal behaviour with balance-of-plant components and heat-integration strategies. Two application pathways are considered. In the reference plant, H₂ for conventional CO₂ methanation is supplied by a PEM electrolyser. Within this work, alternative concepts based on SOEC technology are investigated using simulation. In a simulations study, a SOEC steam electrolysis is evaluated to supply H₂ for conventional CO₂ methanation. Further, SOEC co-electrolysis is assessed in the simulation to produce tailored syngas for CO methanation with enhanced heat-recovery potential and reduced H₂ demand. Overall, the results indicate that coupling SOEC-based conversion with methanation can improve carbon utilisation, increase renewable methane output, and support flexible operation aligned with grid constraints and seasonal demand.
Downloads
References
[1] BMK. “Gasmarktbericht 2024.” [Online]. Available: energie.gv.at
[2] E-Control, „Erdgas in Österreich - Marktstatistik,“ Vienna/Austria, 2025. Accessed: Feb. 26, 2026. [Online]. Available: https://www.e-control.at/statistik/g-statistik/charts/gas07_str
[3] International Monetary Fund. European Dept., “Austria: Selected Issues,” IMF Staff Country Re-ports, no. 160, 2025, doi: 10.5089/9798229015783.002.
[4] AGGM - Austrian Gas Grid Management, „ONE100 - Bedarfsdeckung erneuerbare Gase,“ Vien-na/Austria, 2024.
[5] Umweltbundesamt, „Potenziale erneuerbarer Gase in Österreich 2023,“ Vienna/Austria, 2023.
[6] Lehrstuhl für Energieverbundtechnik EVT), „Grünes Gas Steiermark – Berechnung von Bandbrei-ten erschließbarer Potenziale an Bio-methan und Synthetic Natural Gas (SNG) aus Reststoffen unter Einbindung eines Stake-holderprozesses,“ Montanuniversität Leoben, Graz,Leoben/Austria, 2024.
[7] E-Control, „Gasmarktbericht Österreich - Speicher und Infrastruktur,“ Vienna/Austria, 2024.
[8] E-Control, „Erdgas in Österreich - Betriebsstatistik: Erdgasbilanz,“ Vienna/Austria, 2026. Ac-cessed: Feb. 26, 2026. [Online]. Available: https://www.e-control.at/statistik/g-statistik/charts/gas01_bil2
[9] Bundesministerium für Klimaschutz, Umwelt, Energie, Mobilität, Innovation und Technologie (BMK), „Erneuerbares-Gas-Gesetz – EGG (251/ME): Ministerialentwurf Gesetz,“ Parlament Öster-reich, Vienna/Austria, 2023. Accessed: Mar. 10, 2026. [Online]. Available: https://www.parlament.gv.at/gegenstand/XXVII/ME/251
[10] Richtlinie G B210: Gasbeschaffenheit, G B210, Österreichische Vereinigung für das Gas- und Wasserfach (ÖVGW), Wien, 2021. [Online]. Available: https://www.austrian-standards.at/de/shop/ovgw-g-b210-2021-06~p2579867
[11] R. K. Kumar and P. Samuel, “Designing a hydrogen generation system through PEM water elec-trolysis with the capability to adjust fast fluctuations in photovoltaic power,” International Journal of Hydrogen Energy, vol. 82, pp. 1–10, 2024, doi: 10.1016/j.ijhydene.2024.07.376.
[12] A. Buttler and H. Spliethoff, “Current status of water electrolysis for energy storage, grid balanc-ing and sector coupling via power-to-gas and power-to-liquids: A review,” Renewable and Sus-tainable Energy Reviews, vol. 82, pp. 2440–2454, 2018, doi: 10.1016/j.rser.2017.09.003.
[13] S. Shiva Kumar and H. Lim, “An overview of water electrolysis technologies for green hydrogen production,” Energy Reports, vol. 8, pp. 13793–13813, 2022, doi: 10.1016/j.egyr.2022.10.127.
[14] M. Götz et al., “Renewable Power-to-Gas: A technological and economic review,” Renewable Energy, vol. 85, pp. 1371–1390, 2016, doi: 10.1016/j.renene.2015.07.066.
[15] European Biogas Association (EBA). “Presentation of the Audi e-gas plant Werlte: Reported efficiency data.”
[16] M. Thema, F. Bauer, and M. Sterner, “Power-to-Gas: Electrolysis and methanation status review,” Renewable and Sustainable Energy Reviews, vol. 112, pp. 775–787, 2019, doi: 10.1016/j.rser.2019.06.030.
[17] K. J. Yoon, S. Lee, S.-Y. Park, and N. Q. Minh, “Advances in high-temperature solid oxide elec-trolysis technology for clean hydrogen and chemical production: materials, cells, stacks, sys-tems and economics,” Progress in Materials Science, vol. 154, p. 101520, 2025, doi: 10.1016/j.pmatsci.2025.101520.
[18] L. Wang, M. Pérez-Fortes, H. Madi, S. Diethelm, J. Van herle, and F. Maréchal, “Optimal design of solid-oxide electrolyzer based power-to-methane systems: A comprehensive comparison be-tween steam electrolysis and co-electrolysis,” Applied Energy, vol. 211, pp. 1060–1079, 2018, doi: 10.1016/j.apenergy.2017.11.050.
[19] J. B. Hansen, F. Fock, and H. H. Lindboe, “Biogas Upgrading: By Steam Electrolysis or Co-Electrolysis of Biogas and Steam,” ECS Trans., vol. 57, no. 1, pp. 3089–3097, 2013, doi: 10.1149/05701.3089ecst.
[20] M. A. Laguna-Bercero, “Recent advances in high temperature electrolysis using solid oxide fuel cells: A review,” Journal of Power Sources, vol. 203, pp. 4–16, 2012, doi: 10.1016/j.jpowsour.2011.12.019.
[21] M. de Saint Jean, P. Baurens, C. Bouallou, and K. Couturier, “Economic assessment of a power-to-substitute-natural-gas process including high-temperature steam electrolysis,” International Journal of Hydrogen Energy, vol. 40, no. 20, pp. 6487–6500, 2015, doi: 10.1016/j.ijhydene.2015.03.066.
[22] E. Giglio, A. Lanzini, M. Santarelli, and P. Leone, “Synthetic natural gas via integrated high-temperature electrolysis and methanation: Part I—Energy performance,” Journal of Energy Stor-age, vol. 1, pp. 22–37, 2015, doi: 10.1016/j.est.2015.04.002.
[23] S. D. Ebbesen, J. B. Hansen, and M. Mogensen, “Biogas Upgrading Using SOEC with a Ni-ScYSZ Electrode,” ECS Trans., no. 57, 2013, Art. no. 1, doi: 10.1149/05701.3217ecst.
[24] J. Irvine and N. Zhang, “Utilising Solid Oxide Electrolysis to Enhance Model Biogas Mixtures, Understanding the Interplay between Catalysis and Electrolysis,” ECS Meeting Abstracts, Volume Ma2025-03, SOFC: 19th International Symposium on Solid Oxide Fuel Cells (SOFC-XIX), 2025. doi: 10.1149/MA2025-031252mtgabs. [Online]. Available: https://iopscience.iop.org/article/10.1149/MA2025-031252mtgabs/meta#artAbst
[25] Haldor Topsoe A/S, “Biogas-SOEC: Electrochemical upgrading of biogas to pipeline quality by means of SOEC electrolysis,” ForskNG 2011 Project no. 10677, 2012.
[26] Bioenergy Europe. “Biogas.” Accessed: Feb. 12, 2026. [Online]. Available: https://bioenergyeurope.org/glossary/biogas/
[27] Naskeo Environnement. “The Biogas.” Accessed: Dec. 12, 2026. [Online]. Available: https://www.biogas-renewable-energy.info/biogas_composition.html
[28] A. Petersson and A. Wellinger, “Biogas upgrading technologies - developments and innovations: Task 37 - Energy from biogas and landfill gas,” 2009.
[29] K. Sasaki, “Sulfur Tolerance of Solid Oxide Fuel Cells,” Proc. Vol., 2005-07, pp. 1267–1274, 2005, doi: 10.1149/200507.1267PV.
[30] J. F. Rasmussen and A. Hagen, “The effect of H2S on the performance of Ni–YSZ anodes in solid oxide fuel cells,” Journal of Power Sources, no. 191, pp. 534–541, 2009, doi: 10.1016/j.jpowsour.2009.02.001.
[31] E. Ryckebosch, M. Drouillon, and H. Vervaeren, “Techniques for transformation of biogas to biomethane,” Biomass and Bioenergy, no. 35, pp. 1633–1645, 2011, doi: 10.1016/j.biombioe.2011.02.033.
[32] S. D. Ebbesen and M. Mogensen, “Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells,” Journal of Power Sources, no. 193, pp. 349–358, 2009, doi: 10.1016/j.jpowsour.2009.02.093.
[33] A. Abu Hajer and J. P. Trembly, “Effect of sulfur poisoning on carbon dioxide electroreduction in solid oxide electrolyzer cells,” Electrochimica Acta, no. 537, p. 146757, 2025, doi: 10.1016/j.electacta.2025.146757.
[34] A. Hagen, J. F. Rasmussen, and K. Thydén, “Durability of solid oxide fuel cells using sulfur con-taining fuels,” Journal of Power Sources, no. 196, pp. 7271–7276, 2011, doi: 10.1016/j.jpowsour.2011.02.053.
[35] M. Ashrafi, C. Pfeifer, T. Pröll, and H. Hofbauer, “Experimental Study of Model Biogas Catalytic Steam Reforming: 2. Impact of Sulfur on the Deactivation and Regeneration of Ni-Based Cata-lysts,” Energy Fuels, no. 22, pp. 4190–4195, 2008, doi: 10.1021/ef8000828.
[36] J. R. Rostrup-Nielsen, “Sulfur-Passivated Nickel Catalysts for Carbon-Free Steam Reforming of Methane,” Journal of Catalysis, no. 85, pp. 31–43, 1984.
[37] J. Ren, H. Lou, N. Xu, F. Zeng, G. Pei, and Z. Wang, “Methanation of CO/CO2 for power to me-thane process: Fundamentals, status, and perspectives,” Journal of Energy Chemistry, vol. 80, pp. 182–206, 2023, doi: 10.1016/j.jechem.2023.01.034.
[38] A. Tripodi, F. Conte, and I. Rossetti, “Carbon Dioxide Methanation: Design of a Fully Integrated Plant,” Energy Fuels, vol. 34, no. 6, pp. 7242–7256, 2020, doi: 10.1021/acs.energyfuels.0c00580.
[39] S. Rönsch et al., “Review on methanation – From fundamentals to current projects,” Fuel, vol. 166, pp. 276–296, 2016, doi: 10.1016/j.fuel.2015.10.111.
[40] J. Kopyscinski, T. J. Schildhauer, and S. M. Biollaz, “Production of synthetic natural gas (SNG) from coal and dry biomass – A technology review from 1950 to 2009,” Fuel, vol. 89, no. 8, pp. 1763–1783, 2010, doi: 10.1016/j.fuel.2010.01.027.
[41] S. Beringer, M. Macherhammer, and A. Trattner, “Developing Simulation Models to Enhance Ef-ficiency and Longevity of Solid Oxide Electrolyser Cells in Co-Electrolysis Operation,” FC3 Fuel Cell Conference, vol. 2024, no. 1, pp. 15–25, 2024.
[42] S. Beringer, K. Treusch, B. Grabner, M. Macherhammer, and A. Trattner, “Simulation-based opti-mization of an SOEC system for co-electrolysis operation: A0918,” European SOFC and SOE Fo-rum, vol. 16, 2024.
[43] L. Wang et al., “Power-to-methane via co-electrolysis of H2O and CO2: The effects of pressurized operation and internal methanation,” Applied Energy, vol. 250, pp. 1432–1445, 2019, doi: 10.1016/j.apenergy.2019.05.098.
[44] J. Dragsbæk Duhn, A. Degn Jensen, S. Wedel, and C. Wix, “Modeling of Gas Diffusion in Ni/YSZ Electrodes in CO2 and Co‐electrolysis,” Fuel Cells, vol. 17, no. 4, pp. 442–456, 2017, doi: 10.1002/fuce.201700068.
[45] M. Ni, “An electrochemical model for syngas production by co-electrolysis of H2O and CO2,” Journal of Power Sources, vol. 202, pp. 209–216, 2012, doi: 10.1016/j.jpowsour.2011.11.080.
[46] J. Aicart, “Modeling and experimental validation of high temperature steam and carbon dioxide co-electrolysis,” Dissertation, Universite de Grenoble, 2016. [Online]. Available: https://theses.hal.science/tel-01284476
[47] H. Zhu, R. J. Kee, V. M. Janardhanan, O. Deutschmann, and D. G. Goodwin, “Modeling Elemen-tary Heterogeneous Chemistry and Electrochemistry in Solid-Oxide Fuel Cells,” Journal of the Electrochemical Society, vol. 152, no. 12, A2427-A2440, 2005, doi: 10.1149/1.2116607.
[48] V. Menon, Q. Fu, V. M. Janardhanan, and O. Deutschmann, “A model-based understanding of solid-oxide electrolysis cells (SOECs) for syngas production by H2O/CO2 co-electrolysis,” Jour-nal of Power Sources, vol. 274, pp. 768–781, 2015, doi: 10.1016/j.jpowsour.2014.09.158.
[49] V. Novaresio, M. García-Camprubí, S. Izquierdo, P. Asinari, and N. Fueyo, “An open-source li-brary for the numerical modeling of mass-transfer in solid oxide fuel cells,” Computer Physics Communications, vol. 183, no. 1, pp. 125–146, 2012, doi: 10.1016/j.cpc.2011.08.003.
[50] P. Kazempoor and R. J. Braun, “Model validation and performance analysis of regenerative solid oxide cells: Electrolytic operation,” International Journal of Hydrogen Energy, vol. 39, no. 6, pp. 2669–2684, 2014, doi: 10.1016/j.ijhydene.2013.12.010.
[51] J. Laurencin, D. Kane, G. Delette, J. Deseure, and F. Lefebvre-Joud, “Modelling of solid oxide steam electrolyser: Impact of the operating conditions on hydrogen production,” Journal of Pow-er Sources, vol. 196, no. 4, pp. 2080–2093, 2011, doi: 10.1016/j.jpowsour.2010.09.054.
[52] M. He, X. Qi, X. Liu, C. Su, and N. Lv, “Estimating the viscosity of pure refrigerants and their mixtures by free-volume theory,” International Journal of Refrigeration, vol. 54, pp. 55–66, 2015, doi: 10.1016/j.ijrefrig.2015.03.010.
[53] S. Megel and M. Jahn. “Online Global Technical Conference 2020 Fuel Cell Technology.” Ac-cessed: Feb. 26, 2026. [Online]. Available: https://publica-rest.fraunhofer.de/server/api/core/bitstreams/87960cca-637c-4217-904d-b5a12ad97c09/content
[54] M. Kusnezoff et al., “Progress in SOC Development at Fraunhofer IKTS,” in ECS Meeting Ab-stracts: 17th International Symposium on Solid Oxide Fuel Cells (SOFC-XVII), vol. MA2021-03 197, The Electrochemical Society, Ed., 2021. Accessed: Mar. 3, 2026. [Online]. Available: https://share.google/Xu8Rj4Cn22ki21GJp
[55] The Electrochemical Society, Ed. ECS Meeting Abstracts: 17th International Symposium on Solid Oxide Fuel Cells (SOFC-XVII), 2021.
[56] M. Kusnezoff, N. Trofimenko, M. Müller, and A. Michaelis, “Influence of Electrode Design and Contacting Layers on Performance of Electrolyte Supported SOFC/SOEC Single Cells,” Materi-als (Basel, Switzerland), early access. doi: 10.3390/ma9110906.
[57] Y. Chi, K. Yokoo, H. Nakajima, K. Ito, J. Lin, and Y. Song, “Optimizing the homogeneity and efficiency of a solid oxide electrolysis cell based on multiphysics simulation and data-driven sur-rogate model,” Journal of Power Sources, vol. 562, p. 232760, 2023, doi: 10.1016/j.jpowsour.2023.232760.
[58] S. Jaison et al., “Solid oxide electrolysis cell and stack testing best practices,” International Journal of Hydrogen Energy, vol. 148, p. 149961, 2025, doi: 10.1016/j.ijhydene.2025.06.151.
[59] V. Subotić and C. Hochenauer, “Analysis of solid oxide fuel and electrolysis cells operated in a real-system environment: State-of-the-health diagnostic, failure modes, degradation mitigation and performance regeneration,” Progress in Energy and Combustion Science, vol. 93, p. 101011, 2022, doi: 10.1016/j.pecs.2022.101011.
[60] Z. Xia et al., “Modeling and analysis of cross-flow solid oxide electrolysis cell with oxygen elec-trode/electrolyte interface oxygen pressure characteristics for hydrogen production,” Journal of Power Sources, vol. 529, p. 231248, 2022, doi: 10.1016/j.jpowsour.2022.231248.
[61] Y. Zhao et al., “System level heat integration and efficiency analysis of hydrogen production process based on solid oxide electrolysis cells,” International Journal of Hydrogen Energy, vol. 46, no. 77, pp. 38163–38174, 2021, doi: 10.1016/j.ijhydene.2021.09.105.
[62] R. K. Sinnot, J. M. Coulson, and J. F. Richardson, Chemical Engineering Design: Volume 6, 4th ed. (6). Elsevier Butterworth-Heinemann, 2005.
[63] Y. Luo, Y. Shi, and N. Cai, “Chapter 2 - Distributed hybrid system and prospect of the future Energy Internet,” in Hybrid Systems and Multi-energy Networks for the Future Energy Internet, Y. Luo, Y. Shi, and N. Cai, Eds., 1st ed. Academic Press, pp. 9–39. Accessed: Mar. 8, 2026.
[64] T. A. Davidson. “Report of Investigations 9456: A Simple and Accurate Method for Calculating Viscosity of Gaseous Mixtures.” NIOSH Numbered Publications. Accessed: Mar. 9, 2026. [Online]. Available: https://stacks.cdc.gov/view/cdc/10045
Published
How to Cite
Conference Proceedings Volume
Section
License
Copyright (c) 2026 Stefan Beringer, Julian Gruber, Stefan Sturm, Klara Treusch, Marie-Gabrielle Macherhammer, Vanja Subotić, Alexander Trattner
This work is licensed under a Creative Commons Attribution 4.0 International License.
Funding data
-
Österreichische Forschungsförderungsgesellschaft
Grant numbers 892427