January 13, 2023
16:15
Louvain-la-Neuve
Auditorium BARB 91
Title:
Development and application of poly (ionic liquid) composite membranes with immobilized carbonic anhydrase for CO2 absorption in gas-liquid membrane contactors
Abstract:
In the current climate crisis, CO2 capture and utilization appears to be essential in achieving the climate targets and promoting the transition towards a society entirely relying on renewable energies. Among the alternatives, CO2 can be utilized as sodium bicarbonate salts, NaHCO3. This product is obtained by absorbing CO2 into Na2CO3 aqueous solutions, which are kinetically limited solvents. Nevertheless, adding promoters such as the biocatalyst carbonic anhydrase can enhance their absorption rate. The enzyme is exceptionally active and can work in mild conditions. However, enzymes are homogenous catalysts with limited stability. This issue can be addressed through enzyme immobilization on a support, as this approach leads to easier separation and enzyme conformational stabilization. In the targeted application, the immobilized enzyme must be placed close to the gas-liquid interface to fully take advantage of its catalytic properties. Thus, gas-liquid membrane contactors with carbonic anhydrase immobilized on the membrane surface are a promising technology for accelerating the absorption of CO2.
This work's novelty comes from employing ionic liquid-derived materials, mainly polymerized ionic liquids or poly(ionic liquid)s, a class of tunable CO2-philic polymers, to anchor the enzyme to the membrane surface. Different immobilization approaches were compared: entrapment, physical adsorption, and covalent bonding. The most promising results were obtained with the physical adsorption of carbonic anhydrase on hydrophilic poly(ionic liquid)s. The carrier was shaped as a thin film coating a porous hydrophobic support. The resulting biocatalytic composite membranes presented several interesting features, such as preservation of the native enzyme activity upon immobilization, excellent reusability, structutral integrity, and a significant enhancement of the CO2 mass transfer. Indeed, the novel membranes increased the mass transfer of OC2 by a factor of 45 (in optimal conditions) compared to the commercial membrane support without any modification. Overall, the materials developed during the PhD thesis displayed interesting performance for the application in CO2 capture and utilization.
Jury Members:
Prof. Patricial Luis Alconero (UCLouvain), supervisor
Prof. Eric Deleersnijder (UCLouvain), chairperson
Prof. Damien Debecker (UCLouvain), secretary
Prof. Patrice Soumillon (UCLouvain)
Prof. Grégoire Léonard (ULiège)
Prof. Wojciech Kujawski (Nicolaus Copernicus University in Torun, Poland)
Dr. Lidietta Giorno (National Research Council of Italy, Italy)