Advances in CO2 capture at Air Liquide

Air Liquide is currently developing multiple, economically competitive CO2 capture technologies utilizing optimized common technology blocks. This approach provides the flexibility required to economically meet the technically complex requirements of CO2 capture from coal fired power plants. In the case of CO2 capture via the oxycombustion route, Air Liquide has developed innovations for the ASU (Air Separation Unit) and the CPU (Cryogenic Purification Unit). Pilot projects at various scale have been done or are in various stages of progress for Total Lacq, CIUDEN, Callide Oxyfuel and FutureGen 2.0. Beyond CO2 capture from power plants, the Cryocap™ CPU technology has been adapted to other industrial processes such as H2 and iron/steel production. The CO2 captured through Cryocap™ processes can be suitable for either sequestration or enhanced oil recovery.
Air Liquide is also developing a CO2 capture process based on sub-ambient temperature operation of a hollow fiber membrane in combination with cryogenic distillation. The proposed hybrid CO2 capture process concept couples the unique high performance membrane with cryogenic processing technology to efficiently capture at least 90% of the CO2 in the flue gas from an air fired coal power plant. Operation of these commercial Air Liquide membranes at low temperatures provides an unprecedented combination of CO2 permeability and selectivity. Both high membrane module productivity and high selectivity are critical for cost-efficient CO2 capture. High selectivity reduces the energy cost of CO2 capture while high module productivity reduces the capital cost of the membrane system. CPU technology downstream of the membrane is used to meet CO2 purity specifications for sequestration or enhanced oil recovery.

With support from DOE / NETL, Air Liquide has successfully completed a long-term (8 month) test of the enhanced CO2 separation capability of the Air Liquide sub-ambient temperature membrane. This demonstration was carried out with commercial membrane modules using a synthetic CO2/N2 feed. This work is an important milestone in the validation of the cold membrane process. The cold membrane process is on track for field testing using pre-treated flue gas from an air fired coal power plant at the National Carbon Capture Center.