State-of-the-art imaging is transforming how we study porous media, yet access to advanced facilities and expertise can remain a major barrier. In this talk, I will introduce the EXCITE Network, a European initiative that provides free-of-charge transnational access to leading imaging infrastructures and specialist support for Earth and Environmental sciences.
EXCITE brings together...
Mixing and clogging phenomena in porous media are of major interest in both industry and agronomy. While numerous studies have investigated the macroscopic influence of porous microstructure on flow, the exact flow paths have long remained inaccessible due to the opacity of most natural media. In this work, we use X-ray 3D tomographic data to fabricate transparent resin replicas of porous...
The study of dynamic processes in porous and confined media, such as phase transitions, interfacial transport, and crystal growt, under extreme environmental conditions (e.g., high pressure, low temperature, corrosive fluids) remains a formidable experimental challenge. While advanced imaging techniques including X-ray computed tomography and laser scanning microscopy have greatly enhanced our...
Tomographic techniques play an important role in the parametrization and validation of reactive transport models by enabling spatially and temporally resolved observations of transport processes. Imaging-based approaches, in particular, enable direct observation of flow paths that are impossible to infer from bulk measurements alone. These approaches also allow for the detection of localized...
Scope and Objective
Digital Rock technologies integrate 3D micro-CT imaging with computer vision and physics simulators to expedite and reduce the cost of rock property prediction. Key challenges here are the hardware-imposed limit on resolution and artefacts generated during the reconstruction of 2D projections to a 3D image. Consequently, boundaries between two phases appear as...
Understanding fluid dynamics within porous materials is fundamental to a wide range of critical applications, from the design of geo-energy systems, such as subsurface hydrogen storage, to electrochemical devices. Accurate flow modelling remains challenging due to the inherently multiscale and dynamic nature of these systems, for instance in multiphase and viscoelastic flows, resulting in high...
Building on a decade of expertise in neutron imaging developed by our group, this paper presents a novel experiment focusing on the coupled thermo-hydro-mechanical processes driving concrete spalling at high temperatures.
Conventional methods, limited to post-mortem analysis or intrusive gauges, fall short in capturing the transient (coupling of heat, moisture and stress) that leads...
Microscopic multiphase fluid dynamics in porous media form the basis of various macroscopic phenomena in geological and industrial applications. Dynamic X-ray micro-CT enables us to study how fluid distributions evolve in 3D at the pore scale in opaque samples without interfering with the system, and has thus become a key tool for in-situ visualization of dynamic multiphase flow processes in...
Small-scale heterogeneities influence the migration and trapping of CO$_2$ in porous rocks. Quantifying their impact is essential for accurately predicting CO$_2$ migration in the subsurface for geological carbon storage. Here, we investigate the influence of small-scale heterogeneities in a core sample obtained from the monitoring well of an active geological carbon storage site; the Otway...
Understanding how fluids move, mix, and react inside natural porous media is central to subsurface decarbonization (CO₂ trapping/mineralization) and hydrogen-related geo-energy systems, yet remains challenging because the controlling mechanisms span extreme ranges of chemistry, space and time. At the ESRF, we develop and operate an experimental imaging platform (ACHELOS) that explicitly...
Beam hardening (BH) artifacts in polychromatic CT and micro-CT (µCT) of geological materials hinder quantitative analysis of density and effective atomic number. This study develops and validates a dual-energy µCT workflow in 2D parallel-beam geometry to correct for BH and provide a robust link between measured attenuation and density and effective atomic number. We systematically investigate...
Density-driven convection enhances the carbon dissolution rate, which is significant for the geological carbon storage. This process will also influence the spatiotemporal pH and carbon concentration of the underground fluid. To illuminate the convection mechanism, it is critical to understand the evolution of those properties within the porous media. However, determining the spatiotemporal pH...
In this study, comprehensive micro-CT and SEM analyses were conducted on wellbore cement (both a control wellbore cement sample and a CO2-resisting biochar-modified wellbore cement sample) exposed to high pressure CO2, mimicking typical geologic CO2 storage conditions. Micro-CT and SEM images revealed that for CO2 alteration of the control sample, the pore volume at the sample surface...
- Background & Motivation
Proton exchange membrane water electrolysis (PEMWE) is recognized as one of the promising options for green hydrogen production. To achieve high current density operation, efficient mass transport within the porous media is essential. While many studies have focused on oxygen gas removal in the anode porous transport layer (PTL), as pointed out in a recent review...
This study explores the application of advanced transmission electron microscopy (TEM) techniques in characterizing the microstructure of porous materials, with a specific focus on geomaterials, such as feldspar and hydrotalcite. High-resolution TEM (HRTEM) and scanning transmission electron microscopy (STEM) are employed to investigate the pore structure, surface morphology, and...
The microstructure evolution of sodium geopolymers - comprising a reactive solid matrix and an evolving void network - is tracked in time using synchrotron 4D X-ray micro-computed tomography (µCT) to capture foaming from its earliest stages through growth, coalescence, and stabilization. Advanced segmentation is employed to overcome limited contrast and reconstruction artefacts that obscure...
Dissolution and exsolution processes are key mechanisms to constrain when partially-soluble fluids exist together within the confined architecture of a porous medium. This scenario is prevalent in engineered and natural processes; e.g. air-water flows in the vadose zone, remediation of non-aqueous phase liquids (NAPLs) in groundwater and soil environments, storage of hydrogen and carbon...
Cooling-induced salt precipitation occurs in many natural and engineered systems. For example, in porous building materials, salt crystallization driven by temperature fluctuations may lead to progressive degradation of infrastructure and cultural heritage. In soils, it may affect their geotechnical properties, particularly in freeze–thaw settings. While other forms of induced salt...
Wood and wood-based composites are increasingly studied for their potential to regulate indoor humidity through moisture exchange with the air. Understanding their dimensional stability under fluctuating moisture conditions is essential for uncovering the underlying mechanisms and their practical use. This study employed neutron imaging to elucidate the moisture dynamics within wood materials...
For more than 20 years, X-ray microtomography (µCT) has been extensively used to study dry snow (see e.g.[ [1][1], [2]][2]). However, imaging of wet snow still resists the µCT approach for several reasons: (1) the low absorption contrast between ice and liquid water, (2) the difficulty of regulating temperature at 0 °C and (3) some very rapid processes that may occur during ice melting and...
To assess the resilience of wood assemblies to dry without damage under post-flooding situations, hygrothermal computational simulations require additional information to the standard boundary conditions usually imposed under normal environmental conditions. We perform neutron imaging to characterize water distribution within the interstices of wood assemblies, and propose to impose a moisture...
Repeated laboratory experiments of complex physics often exhibit significant physical variability. Image-based analysis provides a powerful approach to investigate such variability. In this work, we employ optimal transport metrics to quantify differences across entire experimental datasets, enabling systematic clustering and identification of structural similarities. We present a complete...
When matrix-dissolving fluids flow through porous media, a positive feedback loop between fluid movement and chemical reaction creates evolving dissolution patterns. These patterns range from nearly uniform fronts to highly complex, branched channels known as wormholes.
This hydrochemical instability is sensitive not only to flow parameters but also to spatial heterogeneity of the porous...
Wettability is a fundamental parameter in the petrophysical characterization of reservoir rocks, as it controls fluid distribution, capillary displacement, and hydrocarbon recovery efficiency (Morrow, N. R., 1990; Blunt, M. J., 2017). This study investigates the wettability of a miniplug sample from Brazilian pre-salt reservoir rocks using high-resolution X-ray microcomputed tomography...
