Recent advancements in carbonic anhydrase immobilization and its implementation in CO2 capture technologies: A review

Abstract

Currently, amine-based solutions are considered as benchmark absorbents for CO2 capture. However, there are severe environmental concerns as well as high energy consumption. A viable option is CO2 capture utilising water as absorbent, via a biomimetic approach by the enzyme carbonic anhydrase (CA), with high selectivity, upmost performance, and environmental friendliness. However, the employment of the free form of CA in industrial applications is not rational due to the considerable amounts of enzyme required, instability and non-reusability. The immobilization of CA has attained significant interest, appearing as a promising approach to solve the problems associated with free CA. In this context, different immobilization strategies and supports have been developed to ameliorate the activity, stability, and reusability of CA enzyme, lowering the cost and increasing the process efficiency in large-scale applications. CO2 capture has been studied using immobilized CA in various technologies such as absorption columns, selective membranes, and membrane contactors. In this state-of-the-art review, the scientific literature regarding the immobilization of CA and carbon capture technologies using immobilized CA are analyzed, highlighting the benefits, issues, and limitations of processes. Moreover, modelling approaches describing the absorption of CO2 in packed-bed and membrane bioreactors with immobilized CA are presented, as well as the impact of operating parameters on bioreactors performance. The techno-economic analyses carried out on enzymatic capture processes are reviewed as well, to assess their feasibility in an industrial context. Finally, concluding remarks are made with a recommended perspective on open challenges and research priorities.