Numerical models for evaluating the competitive use of the subsurface: the influence of energy storage and production in groundwater

Rainer Helmig

Rainer HELMIG, Institute for Modelling Hydraulic and Environmental Systems, Stuttgart University, Germany.
Abstract

The subsurface is being increasingly utilised both as a resource and as an energy and waste repository. Historically, there have been few issues of concern related to competition between resources, with groundwater contamination being a notable exception. However, with increasing exploitation, resource conflicts are becoming increasingly common and complex. Current issues in this regard include, for example, the long-range impact of mechanical, chemical and thermal energy storage on groundwater resources, and the complex effects surrounding hydraulic fracturing in both geothermal and shale gas production. To analyse and predict the mutual influence of subsurface projects and their impact on groundwater reservoirs, advanced numerical models are necessary. In general, these subsurface systems include processes of varying complexity occurring in different parts of the domain of interest. These processes mostly take place on different spatial and temporal scales. It is extremely challenging to model such systems in an adequate way, accounting for the spatially varying and scale-dependent character of these processes. We will describe the fundamental properties and functions of a compositional multi-phase system in a porous medium. The basic multi-scale and multi-physics concepts are introduced and conservation laws formulated and explain the numerical solution procedures for both decoupled and coupled model formulations. Two applications of multi-physics and multi-scale algorithms will be presented and discussed.



Short biography

Rainer H. Helmig is head of the Department of Hydromechanics and Modelling of Hydrosystems in the Faculty of Civil and Environmental Engineering at the University of Stuttgart, Germany. He gained his doctoral degree from the University of Hannover in 1993 and an advanced research degree (Habilitation) from the University of Stuttgart in 1997. In 1995, he was awarded the renowned "Dresdner Grundwasserforschungspreis" for his doctoral thesis on "Theory and numerics of multiphase flow through fractured porous media". His habilitation thesis was published by Springer in the much-cited textbook "Multiphase flow and transport processes in the subsurface: A contribution to the modeling of hydrosystems". From 1997 to 2000, Rainer Helmig held a professorship in "Computer Applications in Civil Engineering" at the Technical University of Braunschweig. Rainer Helmig's research covers fundamental research and applied science in the field of porous-media flow. A major focus is on developing methods for coupling hydrosystem compartments and complex flow and transport processes.

Design of silica and zeolites monoliths for process intensification in heterogeneous (bio)catalysis and in wastewater treatment

Anne Galarneau

Anne GALARNEAU Institut Charles Gerhardt Montpellier (ICGM) UMR 5253 CNRS-UM-ENSCM, University of Montpellier, France

Abstract

Silica monoliths with hierarchical porosity (macro-/mesoporous), prepared by combining phase separation (spinodal decomposition) and sol-gel process, have demonstrated remarkable potential as supports for catalysts and adsorbents with improved efficiency and productivity of a number of applications in heterogeneous (bio)catalysis, adsorption, separation, water treatments. Monoliths productivities reach 2-4 times the one of packed-bed and 3-10 times the one in batch. This is due to their perfect homogeneous interconnected macroporous network enabling an exceptional mass transfer and a fine control of contact time. In their thin skeleton, their large mesopore volume combined with large mesopore diameters and high surface area allow high diffusion of reactants and products and high reactivity. Silica monoliths have been functionalized by an important variety of moities and techniques, such as grafting with versatile species (acidic, basic), by alumina coating, immobilization of ionic liquids, of enzymes, in-situ synthesis of nanoparticles of Pd and MOF. Their skeleton has been transformed into MCM-41 and zeolites (SOD, LTA, FAU-X) by pseudomorphic transformation. Carbon monoliths have been obtained by replica of silica monoliths. These functional materials reveal great opportunities for process intensification. For examples, LTA and FAU-X monoliths have removed selectively Sr2+ and Cs+, respectively, in simulated radioactive water with perfect breakthrough curves.



Short biography

Dr Anne Galarneau obtained a PhD in Materials Sciences in the Institute of Materials in Nantes, France, in 1993 on the study of lamellar phosphatoantimonic acids for heterogeneous catalysis under the supervision of Y. Piffard and M. Tournoux in collaboration with Rhône-Poulenc. She carried out a post-doc at Michigan State University, USA, in 1993-1995, where she discovered the synthesis of Porous Clay Heterostructures using surfactant-templated mechanism in the group of T. Pinnavaia. She became a CNRS researcher in France in 1995 and joined the Institute Charles Gerhardt in Montpellier, where she developed new synthesis of mesoporous silica prepared by surfactants templating (MCM-41, MCM-48, HMS, SBA-15, KIT-6) with the use of natural surfactants (lecithin) highly suitable for enzymes encapsulation. In particular she discovered the concept of pseudomorphic transformation – inspired by the mineral world – to independently control the textural properties and the morphology (particles, monoliths) of mesoporous silica and zeolites (SOD, LTA, FAU-X). Another key achievement was the characterization of materials porosity to elucidate the complex texture of SBA-15 and mesoporous FAU-Y. Her most recent works concern the elaboration of monoliths with hierarchical porosity, directly usable as reactors, which reveal remarkable performance in (bio)(photo)catalysis and wastewater treatments. She authored 157 publications and 6 patents (h-index 44).

Unravelling pore-scale processes in geomaterial

Veerle CNUDDE

Veerle CNUDDE, Dept. of Geology, Ghent University, Belgium. Holder of the chair “Porous media imaging techniques”, Utrecht University, The Netherlands.

Abstract

Physical, chemical and biological weathering has a constant effect on the earth’s landscape. This also impacts our building infrastructure, as stone and masonry are damaged by a combination of different processes, such as chemical attack, biological colonization, water infiltration and changes in temperature. Fluid flow, reactive transport, nucleation, dissolution, precipitation and mass transport are crucial processes occurring inside the pore system of geomaterials. To fully understand the macroscopical behavior of geomaterials in this context, their pore scale properties and processes have to be understood. The stone’s mineralogy and pore structure strongly affect key internal pore scale processes. These processes have been studied indirectly by micro- and macroscopic observations and laboratory experiments. Although this provides valuable information, the key drivers of these processes are to be studied at the pore scale. To explore these dynamic pore-scale processes, several non-destructive 3D and 4D methods are currently available. These tools provide additional important insights. Unravelling pore-scale processes in combination with pore scale modelling is an essential step towards understanding and predicting a geomaterial’s macroscopic behavior correctly.

The presentation discusses the current possibilities and challenges in non-destructive pore-scale imaging of geomaterials and how this data can be used as input for fluid flow models and their validation. Additional new developments at the synchrotron and on lab-based X-ray systems related to material characterization as well as to the understanding of pore-scale processes are discussed. Examples will be given of different experiments related to the characterization and the imaging of dynamic pore scale processes in (geo)materials.



Short biography

Prof. Veerle Cnudde received a PhD in Geology in 2005 from Ghent University (Belgium) where she has been a research professor since 2010. She is team leader of PProGRess (www.pprogress.ugent.be), the Pore-scale Processes in Geomaterials Research group (Dept. of Geology, UGent) and is one of the coordinators of the Ghent University Expertise Centre for X-Ray Tomography (UGCT). She was one of the co-founders of the UGCT spin-off company Inside Matters, which later merged with the spin-off company XRE, now part of TESCAN.

She specializes in non-destructive imaging of geomaterials and has a strong expertise in real-time imaging of processes in the pore space. Research projects which she has initiated are strongly linked to weathering and fluid flow processes of porous sedimentary rocks, as well as conservation of building stones.

Prof. Veerle Cnudde has published more than 100 peer-reviewed journal articles. She is currently the Chair of the Proposal Review Committee (PRC) of the TOMCAT beamline at Swiss Light Source (SLS). She is one of the co-founders of InterPore BENELUX and an elected Council Member of InterPore. In 2019, she became a part-time Full Professor at the Environmental Hydrogeology group at Utrecht University in the field of “Porous media imaging techniques”. Prof. Veerle Cnudde has been selected by the InterPore award commitee Kimberly-Clark lecturer 2020.

Wetting mechanisms of fibrous materials: from yarn to textile scales

Jan Carmeliet

Jan Carmeliet, Department of Mechanical and Process Engineering, ETH Zürich, Switzerland.

Abstract

Textiles are ubiquitous as clothing, in medical, sport or hygienic care, but also in engineering or architecture. The control of liquid spreading in these materials is often crucial or desirable, such as e.g. moisture management in functional clothing or durability of fiber reinforced materials.
Fast X-ray tomographic microscopy and neutron radiography are used to monitor the imbibition process in yarns at micrometer and centimeter scale, respectively. Observed is a step-wise water uptake process characterized by fast pore filling events of long and narrow pores in the order of seconds and long waiting times between filling events up to several minutes. This step-wise dynamics results in an uptake behavior not following a square root behavior as described by Washburn’s law. The step-wise dynamics are analyzed in terms of the balance between free energy and viscous dissipation, showing waiting times are corresponding to quasi-stable water configurations of almost vanishing free energy gradient.
A pore network model is developed based on the typical pore network topology of yarns and waiting time distributions as observed at micron scale. This network model is upscaled to millimeter scale and validated with the Neutron measurements. The network model allows to analyse in detail the interplay of pore scale processes and pore network topology at lower scales and their impact on experimentally observed processes at macroscale.
We finally study the imbibition process in two connected yarns, called interlaces. We observe that the imbibition process between two yarns may vary highly due to variations in pore connectivity in the contact area. The distribution of waiting times for the transport between two yarns is shifted to longer waiting periods as compared to the distribution of waiting times for the yarn pores.



Short biography

Since June 2008, Jan Carmeliet is full professor at the Chair of Building Physics at the department of Mechanical Engineering at ETH Zürich Switzerland.
Jan Carmeliet, graduated from the Katholieke Universiteit Leuven (K.U.Leuven) and has been Professor at K.U.Leuven since 1998 and part-time Professor at T.U.Eindhoven. He was in 2007 on sabbatical leave at the University of Illinois at Urbana Champaign and at Los Alamos Governmental Laboratories.
His research resulted in more than 330 scientific journal papers.
His research interests concern urban climate and urban heat island mitigation, multiscale behaviour of porous materials and their fluid interactions, and multi-energy decentralized systems at building and urban scale.
He was research councillor of the National Science Foundation Switzerland and expert of the Swiss Innovation Agency (InnoSuisse). He was director of the graduate program ‘master integrated building systems’ at ETHZ. He was member of the research commission of ETH Zürich, the scientific commission of the CCEM (Centre of Competence Energy and Mobility) and the Board of Energy Science Centre ETH Zürich. He plaid a very active role in acquiring and organizing the SCCER (Swiss competence centre energy research) FEEB&D (Future energy efficient buildings and districts).

Closure of the conference

FIC PhD Prize
Awarding (Best PhD poster)