CO2 Capture by Sub-Ambient Membrane Operation

CO₂ Capture by Sub-Ambient Membrane Operation

Air Liquide is developing a cost effective hybrid CO₂ capture process based on sub-ambient temperature operation of a hollow fiber membrane in combination with cryogenic distillation.  Low temperature Air Liquide membranes have shown an unprecedented combination of CO₂ permeability and selectivity in the lab. 

Both high membrane module productivity and high selectivity are critical for cost-efficient CO₂ capture.  The proposed hybrid CO₂ capture process concept couples the unique high performance membrane with cryogenic processing technology to capture at least 90% of the CO₂ in the flue gas from an air fired power plant with a target increase in the levelized cost of electricity of less than 35%.  

The current project phase focuses on reproducing the excellent laboratory scale membrane performance in commercial modules (a 10⁴ scale up in membrane area).  A bench-scale test system was constructed for long term testing of commercial Air Liquide membrane modules with CO₂/N₂ mixtures at sub-ambient conditions.  Air Liquide MEDAL™ 12” and 6” modules were tested at pressures as high as 15 bar and temperatures down to -45°C.  Laboratory work also examined the impact of contaminants on membrane performance.  Experimental results are being used to refine the integrated process simulation.

The process development work is performed by Air Liquide's Delaware Research & Technology Center, USA, in collaboration with MEDAL (Air Liquide's Membrane Business Entity) and Air Liquide Engineering.  The project work is supported by the Department of Energy National Energy Technology Laboratory under Award Number DE-FE0004278 (A. O’Palko program manager).