About the project
Mineralization, the precipitation of minerals from dissolved substances, plays a central role in a large spectrum of processes, including the formation of mineral deposits and the filling of vein networks on geological time scales,, the formation of biominerals,, the remediation of contaminants, the restoration of cultural heritage, the clogging of geothermal wells and the mineral trapping of CO2 in the subsurface,. These dynamics are predominantly represented by Darcy-scale models,,, which describe solute dispersion and reaction processes at scales large enough to treat porous media as continuous entities. While this approach provides a relatively robust characterization of dissolution, with the reactive surface area as the main adjustable parameter, it currently fails at capturing important properties of mixing-induced reactions. High-resolution observations have thus shown that pore-scale solute gradients play a key role in mineralization processes by creating local hot spots of precipitation (Figure 1). MinMix will approach this problem by leveraging recent advancements in both measurement and modelling of mixing phenomena to elucidate the role of pore-scale mixing in mineralization.
Objectives and aims
● Obtain joint 4D (3D + time) images of fluid mixing and mineralization at the pore scale in rocks to demonstrate experimentally how fluid mixing controls the localization and rates of mineralization.
● Develop a reactive transport code that accurately describes pore-scale fluid mixing dynamics, while capturing the essential geochemistry of precipitation, in order to understand and quantify the coupling between transport, fluid mixing, and mineralization in rocks.
● Resolve the upscaling step from pore to core scale to establish the relevant average kinetics that effectively describe the impact of pore scale reactive mixing on mineralization rates at the core scale.
● Apply this new experimental and modelling framework to CO2 mineral trapping in rocks by taking advantage of synergies with current projects at the Njord Centre, University of Oslo (e.g. CO2Basalt).
Project summary
The MinMix team assembles complementary expertise bridging across disciplines, including 4D imaging, reactive transport, fluid dynamics, computational methods and statistical physics. We will develop novel 4D imaging methods for transport and reaction in porous rocks (WP1), highly-resolved reactive transport simulations (WP2), and advanced upscaling theories (WP3) to characterize and model how pore-scale fluid mixing dictates mineralization rates at core-scale. We will thus establish new effective kinetics that can be used as inputs to reactive transport models that do not resolve pore scale mixing. While MinMix will provide new fundamental insights into mineralization dynamics relevant for a range of processes, we will target an application to CO2 mineral trapping in the subsurface, a promising emerging technology for mitigating climate change.
Financing
The Research Council of Norway.
Cooperation
The project is lead by Prof. Tanguy Le Borgne at UIO. The team assembles cross-disciplinary expertise in mixing, reactive transport and upscaling (T. Le Borgne, G. Linga), geochemistry, mineralization and 4D imaging (F. Renard, L. Menegon, B. Cordonnier), and computational fluid dynamics and statistical physics (J. Mathiesen, L. Angheluta).
Publications
Shafabakhsh, P., Le Borgne, T., Renard, F., & Linga, G. (2024). Resolving pore-scale concentration gradients for transverse mixing and reaction in porous media. Advances in Water Resources, 192, 104791.
Sanquer, H., Heyman, J., Hanna, K., & Le Borgne, T. (2024). Microscale chaotic mixing as a driver for chemical reactions in porous media. Environmental Science & Technology, 58(20), 8899-8908.
Shafabakhsh, P., Cordonnier, B., Pluymakers, A., Le Borgne, T., Mathiesen, J., Linga, G., ... & Renard, F. (2024). 4D neutron imaging of solute transport and fluid flow in sandstone before and after mineral precipitation. Water Resources Research, 60(3), e2023WR036293.
Aquino, T., Le Borgne, T., & Heyman, J. (2023). Fluid–solid reaction in porous media as a chaotic restart process. Physical Review Letters, 130(26), 264001.