Performance Simulation and Compression Cost Estimation of CO2 Membrane Capture at Low Feed Concentrations

Carbon capture and utilization (CCU) is a promising approach to mitigating the effects of rising CO2 levels due to industrial use of fossil fuels—particularly for industries that cannot reduce process-related emissions to zero. Although common CO2 capture technologies based on absorption or adsorption have been well established and extensively researched, these methods require substantial investments in plant upgrades. Membrane capture is a possible alternative. While comparative studies have investigated membrane-capture efficiency at medium or high CO2 concentrations—e.g., in retrofitting coal power plants—assessments of membrane performance at low CO2 concentrations are rare. In this study, the performance of CO2 capture membranes specifically for low-concentration flue gas is modeled, and the effects of membrane area, thickness, and pressure ratio are investigated. In addition, the electricity cost of compressing feed streams is used as an estimator of CO2 capture cost per ton of CO2 captured, thereby assessing the viability of membrane capture as retrofit option for small- and mid-sized companies seeking to reduce CO2 emissions. For the membrane configurations and feed-gas CO2 concentrations investigated (1–5%), estimated CO2 capture costs range from 100 to 1200 € per ton of CO2 captured. This wide range highlights the need for more sophisticated retrofit approaches.