Immobilization of carbonic anhydrase for CO2 capture and its industrial implementation: A review

Minimal cost per ton of captured CO2 and associated environmental impacts are considerable barriers for the industrial implementation of post-combustion CO2 capture. Aqueous solvents promoted with the enzyme carbonic anhydrase are a promising alternative to replace energy intensive and environmentally unfriendly amine-based solutions, which are currently benchmark solvents in CO2 absorption. However, using free enzyme in solution requires significant amounts of enzyme in addition to its possible denaturalization. Enzyme immobilization appears as a rational approach to develop a novel CO2 capture system using aqueous solvents. In the recent literature, efforts are focused on the development and characterization of different carriers and immobilization strategies to achieve good activity and stability compared to free enzyme in solution. In the laboratory and the industry, immobilized carbonic anhydrase have been already tested in a variety of configurations including packed columns, gas-liquid membrane contactors, dynamic devices and selective membranes. This article reviews the developments, opportunities and limitations found at laboratory scale as well as in the industry, and brings them together in order to identify the key challenges and perspectives in the industrial implementation of immobilized carbonic anhydrase for CO2 capture.