Electrochemical production of calcium hydroxide for more sustainable lime and cement manufacturing : from fundamental principles to experimental developments

Thursday November 12th, 2026 - 5pm - Auditorium A01 - Hall SCES - Place des Sciences, 2 - 1348 Louvain-la-neuve

Human activities have pushed several planetary boundaries beyond their safe operating limits, calling for a profound transformation towards a more sustainable society. Achieving a sustainable society requires, notably, profound changes in industrial production. Among the most challenging sectors, the cement and lime industries remain major contributors to global CO2 emissions. In this context, this thesis investigates a novel electrochemical pathway for calcium hydroxide production. This approach offers the potential to fundamentally redesign lime and cement manufacturing with a reduced environmental footprint, although it currently remains at a low technology readiness level. The process was experimentally investigated in two-compartment cells. Excess and batch feedstock addition strategies, as well as in-situ and ex-situ precipitation methods, were compared. Based on the theoretical framework developed in this work and experimental results, key guidelines are established to achieve the desired stoichiometry throughout water electrolysis, feedstock dissolution, ion migration, and calcium hydroxide precipitation. The limited CO2 recovery caused by gas-liquid mass transfer limitations was identified, and strategies to overcome this limitation are proposed. Membrane fouling, responsible for voltage instability, was characterized under various operating conditions and strategies to prevent calcium carbonate contamination during ex-situ precipitation are provided. The influence of various natural feedstocks was also investigated. The effect of particle size distribution on dissolution, the congruence of impurity dissolution, and the feasibility of using reclaimed mortar as an alternative feedstock were assessed. The properties of the resulting calcium hydroxide products were compared. Finally, the energy requirements and prospective CO2 emissions of the process are assessed together with other environmental implications. This work establishes the fundamental principles governing electrochemical calcium hydroxide production and provides a coherent framework for its future scale-up. The findings also demonstrate the potential of the electrochemical route to improve both process performance and the sustainability of lime and cement production.

Jury members

Prof. Joris Proost (UCLouvain), Supervisor
Prof. Paul Fisette (UClouvain), Chairperson
Prof. Patricia Luis Alconero (UCLouvain), Secretary
Prof. Tom Leyssens (UCLouvain)
Prof. Diane Thomas (Umons)
Dr. Aurélien Chardon (Carmeuse, Belgique)

Pay attention : the public defense of Rémy Rouxhet will also take place in the form of a videoconference

Wednesday October 21st, 2026 - 4:15pm - Auditorium More 54 - Place Montesquieu 1, 1348 Louvain-la-Neuve

This dissertation addresses a critical challenge in wind energy research: accurately predicting wind turbine wakes using Large Eddy Simulation (LES), which depends heavily on high-quality experimental validation data.

The work introduces a new model-scale wind turbine called TWIST (Turbine for Wind tunnel Investigation & Scaled Testing), designed and experimentally characterized in a controlled wind tunnel environment with detailed hot-wire measurements. On the numerical side, several methodological advances enable cost-efficient and physically consistent LES, including wall-modeled LES implementation, novel inflow control methods (RPS and ACTIF), and a continuous Actuator Line Model (cALM) for representing turbine aerodynamics.

These developments are integrated into an LES-based digital twin of the TWIST experiment. Comparisons with experimental measurements show that the framework captures essential near-wake flow features and reproduces observed trends under varying operating conditions, demonstrating strong predictive quality. Overall, this combined experimental-numerical approach provides a solid foundation for future investigations of wind turbine wakes and more reliable LES-based tools for wind energy research.

Jury members

Prof. Grégoire Winckelmans (UCLouvain), Supervisor
Prof. Jeroen van Beeck (von Karman Institute, Belgique), Supervisor
Prof. Renaud Ronsse (UCLouvain), Chairperson
Dr. Matthieu Duponcheel (UCLouvain), Secretary
Dr. Sophia Buckingham (ENGIE Laborelec, Belgique)
Prof. Sandrine Aubrun (Ecole Centrale de Nantes, France)
Prof. Joris Degroote (UGent, Belgique)

Pay attention : the public defense of Emmanuel Gillyns will also take place in the form of a videoconference

Monday October 19th, 2026 - 1pm - Auditorium AR-38 - Rue Wafelaerts, 47-51 - 1060 Bruxelles

Rapid urbanization, climate change, and structural inequality have intensified food insecurity in informal settlements across the Global South. Focusing on Metropolitan Lima, Peru, this dissertation investigates how urban agriculture (UA) can be operationalized to strengthen food security while accounting for the spatial, infrastructural, social, and governance conditions that shape the development of informal settlements. The research develops and validates the Systemic Urban Metabolism Framework (SUMF), an evidence-based decision-support methodology integrating urban metabolism, system dynamics, spatial analysis, network analysis, and social-science-informed interpretation. Grounded in a 249-household survey conducted in Ciudad de Gosen, Villa María del Triunfo, the framework quantifies food, energy, water, and waste flows; identifies high-leverage variables through network analysis; models alternative UA scenarios; and maps productive opportunities across parcels and interstitial spaces. Results show that UA can make a substantial contribution to local vegetable demand while generating additional environmental and resource benefits. However, productive capacity alone does not determine performance. Water access, tenure security, community organization, governance capacity, collective maintenance, and the distribution of household labor are equally important. The SUMF therefore provides a transferable methodology for planning and evaluating context-sensitive UA interventions in informal settlements, provided that its parameters are recalibrated to local conditions and validated through participatory processes.

Jury members

Prof. Claeys Damien (UCLouvain), Supervisor & secretary
Prof. Dyson Anna (Yale University, United States), Supervisor
Prof. Pleitinx Renaud (UCLouvain), Chairperson
Prof. Biondi Antunez de Mayolo Susana (Universidad Católica del Perú, Perú)
Prof. Quino Javier (Universidad de Lima, Perú)
Prof. Lyons Ben (University of Southern Queensland, Australia)
Prof. Dovey Kim (University of Melbourne, Australia)

Pay attention : the public defense of Alejandra Acevedo de los Rios will also take place in the form of a videoconference

Thursday October 15th, 2026, 4pm - Auditorium BARB91 - Place Sainte-Barbe, 1 - 1348 Louvain-la-Neuve

Nonlinear optical materials are at the heart of modern photonics, enabling technologies such as frequency conversion, ultra-fast switching, and advanced laser systems. However, the discovery of high-performance nonlinear optical crystals is hindered by the stringent and often contradictory requirements they must satisfy, as well as the vastness of chemical space. This thesis addresses this challenge by presenting a combined first-principles and machine learning approach to accelerate the rational design and discovery of nonlinear optical materials. In the first part of this work, we establish the theoretical foundations of nonlinear optics, with a focus on second-harmonic generation, and detail the computational methods rooted in density functional theory and its extensions for predicting linear and nonlinear optical properties.

We then apply these methods to both synthesized and hypothetical materials, providing insights into the origins of their nonlinear responses and validating our computational approaches against experimental data.

This leads us to revisit the sum-over-states approach and derive two new expressions for the SHG components as well as a refined band-resolved analysis to investigate the interactions between the states.

The second part of the work introduces a materials informatics framework that integrates machine learning, federated databases, and high-throughput screening. By leveraging active learning strategies and creating comprehensive datasets of computed refractive indices and second-harmonic generation tensors, we demonstrate how to efficiently explore vast materials spaces and identify promising candidates. The integration of first-principles calculations via modular workflows with machine learning not only accelerates the discovery process but also helps researchers in the understanding of the structure-property relationships governing nonlinear optical behavior. This combined approach paves the way for the development of next-generation nonlinear optical materials tailored to meet the demanding requirements of modern applications across the electromagnetic spectrum.

Jury members

Prof. Gian-Marco Rignanese  (UCLouvain), Supervisor
Prof. Xavier Urbain  (UCLouvain), Chairperson
Prof. Xavier Gonze  (UCLouvain), Secretary
Prof. Christophe De Vleeschouwer (UCLouvain)
Prof. Silvana Botti (Ruhr University Bochum, Germany)
Dr. Alexander Ganose (Imperial College London, UK)

Pay attention : the public defense of Victor Trinquet will also take place in the form of a videoconference

Wednesday October 14, 2026 - 4:00pm - Auditorium CYCL01 – Cyclotron building, Chemin du Cyclotron, 2 - 1348 Louvain-la-Neuve

La réduction de la consommation de matière et d’énergie, ainsi que les enjeux de durabilité, occupent une place centrale dans la construction. Pourtant, les outils numériques ont favorisé une dissociation entre la conception architecturale de formes complexes et leur résolution structurelle ultérieure par l’ingénieur. Lorsque l’équilibre intervient après la définition des formes, ce processus peut conduire à des solutions nécessitant davantage de matière et d’énergie.

On observe ainsi un regain d’intérêt pour les méthodes géométriques, grâce à leur représentation visuelle des forces et des formes. En trois dimensions, les approches fondées sur des diagrammes polyédriques restent toutefois difficiles à généraliser et à manipuler..

Cette recherche développe une méthode générale de statique graphique par vecteurs capable de résoudre des problèmes d’équilibre tridimensionnels. Elle offre aux architectes et aux ingénieurs un outil visuel et intuitif pour comprendre, explorer et concevoir les structures spatiales.

La thèse propose un cadre théorique et computationnel fondé sur l’interdépendance visuelle entre les diagrammes de forme et de forces. Toute modification de l’un affecte l’autre, permettant ainsi de concevoir directement avec les forces.

La contribution principale réside dans la construction de diagrammes de forces composés de vecteurs, grâce à la planarisation de leurs graphes topologiques. Leur manipulation permet d’agir simultanément sur la géométrie et les forces, de vérifier l’équilibre global et local et d’explorer les transformations structurelles.

Ce cadre est implémenté dans un algorithme automatisant la construction et la transformation des diagrammes.

Plusieurs études de cas, à différentes échelles et pour différents matériaux, démontrent l’applicabilité de la méthode.

La statique graphique rend visibles l’équilibre, le cheminement des forces et leur relation avec la forme, soulignant également son intérêt pédagogique.

Jury members

Prof. Denis Zastavni (UCLouvain), supervisor
Prof. Renaud Pleitinx (UCLouvain), chairperson
Prof. Luca Sgambi (UCLouvain), secretary
Prof. Corentin Fivet (EPFL, Suisse)
Ir. Arch. Laurent Ney (ULB + Ney & Partners)
Prof. Joseph Schwartz (ETH Zurich, Suisse)
Prof. Thierry Ciblac (ENSPM PSL, France)

Pay attention : the public defense of Jean-Philippe Jasienski will also take place in the form of a videoconference