High CO₂ permeability of ceramic-carbonate dual-phase hollow fiber membrane at medium-high temperature

CO₂ separation through ceramic-carbonate dual-phase membrane from various industrial carbon sources has become a promising way to solve the high-temperature CO₂ emission. In this study, we synthesize Ce_0.8Sm_0.2O_2-δ(SDC)-carbonate dual-phase hollow fiber membranes using phase inversion method to separate CO₂ under different feed conditions at high temperature. The SDC-carbonate hollow fiber membranes show not only high CO₂ permeation flux but also stable permeation behavior during the test process. The maximum CO₂ permeation flux reaches up to 4.78, 5.46 and 1.79 ml min⁻¹·cm⁻² under the feed condition of 50%CO₂–50%N₂, 5%H₂-47.5%CO₂-47.5%N₂ and 5%O₂–20%CO₂–75%N₂, respectively, at 700 °C. These results are the highest CO₂ permeation flux of the ceramic-carbonate membrane under the similar operation conditions in recent years. The excellent CO₂ fluxes can be attributed to a unique and superior structure and a thinner thickness of the hollow fiber membrane. In addition, the membrane shows a stable time with 85 h during the long-term test process in a 50%CO₂–50%N₂ feed stream.