Biocatalytic composite membranes for CO2 capture

Abstract

Nature has developed very active and specific catalysts that are critical for living organisms’ existence. The application of some of such biocatalysts in CO2 capture and utilization has recently attracted large interest from the research community and the industry [1,2]. For example, they have been applied to CO2 absorption aiming to reduce the liquid side mass transfer resistance. This resistance is dominating the overall mass transfer and it can be reduced by catalyzing the slow CO2 hydration reaction. Besides, they have also been incorporated in selective membranes. These membranes usually displayed improved permeability and selectivity due to the facilitated transport mechanism [2]. In addition, these biocatalysts are usually immobilized in/on a carrier to protect them from the harsh conditions in CO2 capture and ensure long-term stability. Depending on the immobilization method, the immobilization results in different degrees of stabilization and activity loss. We report here the fabrication and characterization of novel composite membranes with immobilized biocatalyst for CO2 bioconversion. These membranes were prepared by a novel method that ensured a good and straightforward biocatalyst immobilization. The membranes were structurally characterized by SEM while their activity in different conditions was evaluated using p-NPA hydrolysis. In addition, to demonstrate their applicability, the biocatalytic composite membranes were tested in a gas absorption set-up showing an increase in the overall mass transfer coefficient with respect to the pristine support. These membranes could also be interesting for other applications as the combination of a selective barrier and the biocatalyst leads to process intensification (reaction + separation in the same device). [1] P. Luis, V. Sang Sefidi, M. Sparenberg, M. Garcia Alvarez. (2021), continuous process and system for the production of sodium bicarbonate crystals, 20211693.5-1108, universite catholique de louvain. (Patent) [2] Molina-Fernández, C., & Luis, P. (2021). Immobilization of carbonic anhydrase for CO2 capture and its industrial implementation: A review. Journal of CO2 Utilization, 47, 101475