Insight and Comparison of Energy-efficient Membrane Processes for CO2 Capture from Flue Gases in Power Plant and Energy-intensive Industry

Membrane systems for CO2 capture have become increasingly attractive due to their higher energy efficiency, smaller footprint, and lower environmental impact. However, membrane systems should be operated at the optimal condition for a given separation scenario to achieve a significant cost-reduction benefit. This work paid particular attention to the insight of membrane system design and comparison of different membranes for various post-combustion CO2 capture scenarios. The four membranes demonstrated at pilot scale have been investigated for carbon capture in the cement factory and fossil fuel-fired power plants, and the specific cost of < 20 $/tonne CO2 captured for both Polaris and PolyActive membranes were found in the scenarios where the flue gases contain high-content CO2 of > 13 vol.%. The membrane units with an estimated footprint of fewer than 7 standard 40-foot containers can be realistically installed in a cement plant. It is recommended that the deployment of membrane systems for CO2 capture should be prioritized in the energy-intensive industries due to a relatively smaller gas volume to be processed compared to power plants. Moreover, membrane systems are better to be operated at a moderate CO2 capture ratio of 70-80 % and pursuing a very high capture ratio of 90 % will not be economically beneficial.