Thesis defense: Maïté MICHAUD

The thesis defense of Maïté MICHAUD will take place on Tuesday 17/12/2019 in the Grand Ampithéâtre of the BU for 9h30

Title : Innovative membrane crystallization contactor – Applications to diffusion/reaction processes

– Muhr Hervé – DR/CNRS Université de Lorraine (Rapporteur)
– Remigy Jean-Christophe – PU/Université Toulouse 3 (Rapporteur)
– Baltes David – Ingénieur Recherche/ Sanofi Sisteron (Examinateur)
– Cognes Claudia – MCU/Université Lyon 1 (Examinatrice)
– Puel François – PU/CentraleSupélec Paris ( Examinateur)
– Mangin Denis – PU/Université Lyon 1 (Directeur de thèse)
– Chabanon Elodie – MCU/ Université Lyon 1 (Co-Directrice de thèse)
– Charcosset Catherine – DR/CNRS Université Lyon 1 (Co-Directrice de thèse)


Membrane processes are considered as one of the most promising breakthrough technology for crystallization/precipitation operations. Porous materials have been extensively investigated but they have shown some serious limitations due to pore blocking and wetting phenomenon. The use of a dense membrane is expected to circumvent the pore blocking issue while keeping the advantages of membrane processes.
In a first part, the model compound, BaCO3, was precipitated within a gas-liquid membrane contactor and a liquid-liquid membrane contactor, working both under static conditions. In this configuration, hydrodynamic influences were avoided. The membrane-crystal interactions were studied using several dense membrane polymers. The experimental results showed that the permeability of both reactant species and the surface tension were the key parameters. Indeed, these two parameters greatly affect both the location of the crystal deposit and its adherence on the membrane surface. Fouling within the membrane and on the surface were prevented with PDMS and Teflon AF2400 which have been found as the two most promising materials for the given application.
In a second part, the same model compound was precipitated in gas-liquid system under dynamic conditions. Self-supporting (PDMS) and composite hollow fibers (PP-Teflon AF2400) were studied. Investigations on the influences of the operating condition showed similar results to those obtained with membrane contactors used for CO2 capture and reported in literature: resistance to mass transfer was mainly located in the liquid phase. Proof of concept was supported by the stable performances obtained with the PP-Teflon AF2400 module of 10 % packing ratio. The module geometry, and more specifically its packing ratio, is an important criterion to take into account so as to avoid module blocking.
Finally, 2D computational fluid dynamics simulations, using the finite element method, were performed. One single kinetic parameter has been used to fit the experimental data. The simulated concentration profiles were not satisfactory. Nonetheless, predictability of the model seems to be promising: crystal productivities were rather well estimated.

Keywords: Crystallization, precipitation, dense membranes, membrane contactors, fouling, modelling.

Date(s) - 17 Dec 2019
9 h 30 min - 11 h 30 min

Bibliothèque de la Doua


Filed under: Defense