Speaker
Description
The European pursuit of a net-zero economy is increasingly defined by two parallel challenges: (1) the urgent mandate to mitigate energy-related greenhouse gas emissions and (2) the necessity of managing the inherent volatility of renewable energy sources. As weather-dependent power production expands, the resulting temporal mismatches between energy supply and consumer demand require the integration of flexible, large-scale seasonal storage solutions. Storing energy in the form of gaseous molecules within subsurface geological formations provides the systemic flexibility required to stabilize the power grid, while offering a transformative pathway to reduce fossil fuel dependence over time.
Geo-methanation represents a transformative technology for circular carbon utilization, enabling the in-situ conversion of hydrogen and carbon dioxide into methane within geological formations. Despite its strategic potential for hydrogen storage and carbon sequestration, the large-scale implementation of subsurface methanation is hindered by fundamental uncertainties regarding conversion efficiency and pore-scale transport dynamics. This research addresses these gaps by establishing a novel, high-resolution experimental-numerical framework designed to resolve the complex interplay between microbial kinetics and multiphase flow.
The originality of this work lies in the development of a microfluidic platform capable of emulating relevant subsurface conditions, integrated with direct numerical simulations (DNS) to bridge the gap between visual observation and mechanistic theory. Through a workflow encompassing micromodel colonization, anaerobic substrate introduction, and gas chromatography, we characterized biomass distribution and methane production kinetics under controlled anaerobic flow regimes.
Our findings reveal three critical insights that redefine the current understanding of subsurface bio-conversion. First, during substrate gas injection, we observed a significant behavioral shift in microbial aggregation, transitioning from a colony-dominated to a planktonic lifestyle. Second, the spatial analysis demonstrated that colony disintegration and subsequent cell migration toward gas–liquid interfaces are primary drivers for enhanced substrate uptake. This phenomenon was quantified by a measured methane evolution rate peaking at approximately 0.35 mmol/L·h, indicating that biomass mobility is essential for maintaining conversion efficiency. Third, through dimensionless analysis, we identified distinct transport regimes within the pore network, ranging from molecular diffusion-limited zones to advection-enhanced mixing areas.
This research demonstrates that the efficacy of geo-methanation in unsaturated environments is governed by a delicate balance of microbial activity, interfacial mass transfer, and advective nutrient supply. By reconciling experimental pore-scale data with calibrated numerical results, this work provides predictive insights necessary to optimize the competitiveness of subsurface environments for renewable energy storage and greenhouse gas mitigation. These results have significant implications for the design of future pilot-scale operations, ensuring that the evolution of hydraulic rock properties and microbial dynamics are accounted for in long-term storage strategies.
| References | [1] Keramidas, K. et al. (2021). Global energy and climate outlook 2020: A new normal beyond COVID-19. JRC Science for Policy Report. doi:10.2760/608429. [2] European Commission (2022). The role of renewable H import & storage to scale up the EU deployment of renewable H. Publications Office of the EU. doi:10.2833/727785. [3] Bouckaert, S. et al. (2021). Net Zero by 2050: A Roadmap for the Global Energy Sector. IEA Report. [4] IPCC (2022). Climate Change 2022: Mitigation of Climate Change. Sixth Assessment Report (WGIII). doi:10.1017/9781009157926. [5] Council of the EU (2024). Fit for 55: Council signs off on gas and hydrogen market package. Press Release. [6] Cifuentes-Faura, J. (2022). European Union policies and their role in combating climate change over the years. Air Quality, Atmosphere & Health. doi:10.1007/s11869-022-01156-5. [7] Heinemann, N. et al. (2021). Enabling large-scale hydrogen storage in porous media – the scientific challenges. Energy & Environmental Science. doi:10.1039/D0EE03536J. [8] Hellerschmied, C. et al. (2024). Hydrogen storage and geo-methanation in a depleted underground hydrocarbon reservoir. Nature Energy. doi:10.1038/s41560-024-01458-1. [9] HyUSPRe (2022). Hydrogen storage potential of existing European gas storage sites. Project Report. [10] HyUnder (2014). Assessment of the potential, actors and business cases for large scale seasonal storage of renewable electricity by hydrogen. Project Report. [11] Strobel, G. et al. (2020). Underground bio-methanation: Concept and potential. Renewable and Sustainable Energy Reviews. doi:10.1016/j.rser.2020.109747. [12] Zauner, A. et al. (2022). Multidisciplinary assessment of a novel carbon capture and utilization concept including underground sun conversion. Energies. doi:10.3390/en15031021. [13] Hemme, C. & van Berk, W. (2018). Hydrogeochemical modeling to identify potential risks of underground hydrogen storage in depleted gas fields. Applied Sciences. doi:10.3390/app8112282. [14] Jasek, P. et al. (2025). Alteration of hydraulic rock properties during subsurface hydrogen methanation. International Journal of Hydrogen Energy. doi:10.1016/j.ijhydene.2025.150191. [15] Dopffel, N. et al. (2021). Microbial side effects of underground hydrogen storage – knowledge gaps, risks and opportunities. International Journal of Hydrogen Energy. doi:10.1016/j.ijhydene.2020.12.058. [16] Hassannayebi, N. et al. (2021). Relationship between microbial growth and hydraulic properties at the sub-pore scale. Transport in Porous Media. doi:10.1007/s11242-021-01680-5. [17] Biehl, J. et al. (2025). Digging deep – governing subsurface uses for the German energy transition. Cleaner Production Letters. doi:10.1016/j.clpl.2025.100099. |
|---|---|
| Country | Austria |
| Green Housing & Porous Media Focused Abstracts | This abstract is related to Green Housing |
| Student Awards | I would like to submit this presentation into the InterPore Journal Student Paper Award. |
| Acceptance of the Terms & Conditions | Click here to agree |
