Public thesis defense Rémy Rouxhet - IMMC
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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)