Application of electrically conductive membrane contactor in the carbon dioxide stripping process for mitigation of fouling induced by flue gas

Carbon capture utilization & storage (CCUS) process is a promising technology for reducing greenhouse gas emissions. However, the biggest challenge in commercializing CCUS is reducing energy consumption during the CO₂ stripping stage. Membrane contactors have been developed to reduce energy consumption and improve CO₂ stripping performance. However, traditional polymer-based membranes are vulnerable to damage by combustion residues such as oil and grease. To address this problem, electrically conductive membranes (ECMs) have been developed to enable efficient electrochemical reactions for anti-fouling purposes. This study investigated the anti-fouling performance of an electrically conductive membrane contactor (ECMC) for CO₂ stripping. Surface modification with a two-layered ECM resulted in the superior electrical conductivity and CO₂ stripping flux compared to other ECMs. Electrostatic repulsion effectively mitigated fouling by 92.1 % compared to non-charged ECMC by preventing the attachment of oil and grease, but it was not observed a significant effect in high oil and grease concentrations. The electrochemical oxidation process when applying a high voltage improved anti-fouling performance, and the O₂ sweep gas mode greatly maintained the CO₂ stripping flux at 95.2 % with high oil and grease concentrations. Furthermore, the feasibility of the ECMC was demonstrated by comparing the predicted total energy consumption per CO₂ amount under actual operating conditions. In conclusion, ECMC improved the energy efficiency of CO₂ stripping by providing high anti-fouling performance in CCUS.