Membrane-cryogenic hybrid CO2 capture—A review
Chunfeng Song, Run Li, Qingling Liu, Shuai Deng, Hailong Li, Jianfeng Sun
Abstract
• The current development status of membrane-cryogenic hybrid CO 2 capture processes were reviewed. • The advantages of hybrid process are compared with standalone membrane or cryogenic processes. • Potential cold-membrane materials and operation mechanism at low temperature is investigated. • The potential intensification strategies of membrane-cryogenic hybrid processes are also discussed. The membrane-cryogenic hybrid process is a promising CO 2 capture process, which combines the advantages of membrane and cryogenic, such as high efficiency (up to 98 % CO 2 captured) and low energy consumption (specific energy consumption around 1.7 MJ/kg CO 2 avoided). Through pretreatment by membranes, CO 2 concentration can be increased, which makes it possible to separate CO 2 via phase change in the cryogenic unit. This work reviews the current status of the development of membrane-cryogenic hybrid processes. The synergy between membrane and cryogenic separation is summarized to identify the bottleneck of such processes and provide insights for process improvement. It was found that cold temperatures would be beneficial to reduce CO 2 activation energy and then improve CO 2 selectivity of membranes. To further improve the CO 2 separation performance, the potential intensification methods of the membrane-cryogenic hybrid process including cold-membrane synthesis, process optimization via heat integration are discussed and envisioned.