Decarbonizing hard-to-abate sectors needs CO₂-to-value routes, yet CO₂’s stability makes CCU energy-intensive. This thesis presents a systematic development of biocatalytic membrane contactors for CCU, using RuBisCO, the primary enzyme for CO₂ fixation in Nature, as the central biocatalyst. Although RuBisCO plays a key role in photosynthesis, its practical application is hindered by slow kinetics, poor CO₂/O₂ selectivity, and poor stability in-vitro. To address these challenges, three main strategies were employed: (i) a CO₂-philic polyionic liquid (PIL) coating to enhance local CO₂ availability, (ii) dendrimer-like hierarchical silica nanoparticles (DHSN) to maximize enzyme loading, and (iii) bio-based polylactic acid (PLA) membranes to improve sustainability. Carbonic anhydrase (CA) was used as a model enzyme to guide initial optimization. The optimized PIL coating created a CO₂- and H₂O-rich microenvironment, significantly enhancing enzyme activity. Two-step covalent immobilization improved enzyme stability in-vitro, while DHSN carriers enabled increased RuBisCO loading and system productivity, though specific activity remained lower than free RuBisCO. PLA membranes supported enzyme immobilization but suffered from limited chemical durability. Co-localization of CA with RuBisCO revealed that CA could deplete local CO₂, reducing RuBisCO productivity in this configuration. This work delivers the first comprehensive evaluation of RuBisCO-based biocatalytic membrane contactors for CCU, highlighting the importance of material selection, immobilization strategy, and system integration. The results emphasize both the promise and the technical challenges of RuBisCO for high-value CO₂ conversion, and reinforce the need for early sustainability assessment. Recommendations for future research include controlling enzyme orientation, exploring greener solvents and crosslinkers, applying machine learning for material optimization, and integrating life cycle analysis for sustainable process design.

Membres du jury :

• Prof. Patricia Luis  (UCLouvain)(Promoteur)
• Prof. Hadrien Rattez  (UCLouvain) (Président)
• Prof. Francesco Contino  (UCLouvain) (Secrétaire)
• Prof. Patrice Soumillion (UCLouvain)
• Prof. Grégoire Leonard (University of Liège)
• Prof. Wenjing Zhang (Technical University of Denmark)

Soutenance publique également accessible par visio-conférence via le lien (TEAMS) : 

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