Enhancing CO2 absorption efficiency using carbonic anhydrase in MDEA-based hollow fibre membrane contactors

Abstract

Global warming, driven by greenhouse gases such as carbon dioxide (CO2), leads to rising global temperatures and climate disruption. CO2, a major contributor to the greenhouse effect, is a critical focus for mitigating climate change through innovative capture and reduction technologies. This paper presents a comprehensive study on the mass transfer simulation of CO2 absorption in a hollow-fibre membrane contactor, utilising chemical and Multiphysics modules for mass transfer and reacting flow within COMSOL software. Theoretical simulations were performed to investigate the absorption process and assess the potential of membrane contactors as an effective strategy for intensified CO2 capture through gas-liquid absorption. The study features an advanced model designed to explore the impact of incorporating human carbonic anhydrase (hCA) with n-methyldiethanolamine (MDEA) solvent in a counter-current hollow fibre membrane contactor. It is demonstrated that hCA with MDEA enhances CO2 absorption by 34 % compared to MDEA due to its high reaction rate. Key operational parameters, such as gas flow rates and thickness, are investigated, and a decrease in CO2 absorption efficiency is observed with these parameters. However, the membrane porosity, fibre length, liquid flow rate, number of fibres, and solvent concentration all contribute to the increased efficiency of absorption. The solvent concentration is analysed to evaluate its impact on mass transfer during CO2 absorption. This integration of the enzyme represents an innovative approach in green chemistry, offering a more sustainable and environmentally friendly solution for CO2 capture.