Bench Scale Testing of Next Generation Hollow Fiber Membrane Modules

Air Liquide is developing a next generation polyimide membrane material (PI-2) for application in our cold membrane hybrid process for CO₂ capture¹. Combining the PI-2 membrane operation with an integrated CO₂ compression and purification unit significantly reduces the overall cost of CO₂ capture. The current work is aimed at developing the PI-2 material to a commercial scale, then validating its performance under real flue gas conditions.

 Previous work showed promising results for the cold membrane hybrid process utilizing the commercially available Air Liquide membrane bundles (PI-1 material)². The cold membrane technology was demonstrated at the National Carbon Capture Center (NCCC) with a 0.3 MWe field-test unit incorporating two 12” diameter PI-1 commercial membrane bundles. That system exceeded its performance targets with stable membrane operation for over 500 hours, and 3,200 hours of total run-time. The cost of 90% CO₂ capture from a 550 MWe net coal power plant was estimated to be between 40 and $45/tonne. Finally, the new PI-2 membrane fiber was tested at a small scale (1” modules) in real flue gas and exhibited up to 10 times the CO₂ permeance and similar CO₂/N₂ selectivity as the commercial PI-1 fiber. This corresponded to a 3 - 5 times increase in the productivity per bundle and a potential cost reduction of $3/tonne for CO₂ capture, as compared with PI-1.

Figure 1. [a] 3D rendering of the 0.3 MWe field-test unit at the NCCC [b] Picture of the field-test unit.

 The current project seeks to develop this next generation PI-2 material to a technology readiness level of 5 via manufacturing scale-up and testing with 300 - 1,000 Nm³/h of real flue gas, 0.1 - 0.3 MWe equivalents³. Several prototype membrane bundles, up to 4” diameter, have been fabricated and tested with synthetic flue gas. These bundles met the project success criteria with a productivity of over 90 Nm³/hr and permeate purity in excess of 60%, at 90% CO₂ recovery. Further manufacturing scale-up is underway such that the first commercial scale bundles (6” diameter) are being fabricated. The commercial scale bundles will be performance tested, first with synthetic flue gas, then with real flue gas at the National Carbon Capture Center.

Figure 2. Performance test data of one of the 4” prototype membrane bundles.

References

¹D. Hasse, S. Kulkarni, E. Sanders, E. Corson, J.-P. Tranier, CO₂ capture by sub-ambient membrane operation, Energy Procedia 37(2013) 993-1003.

²T. Chaubey, CO₂ capture by cold membrane operation with actual power plant flue gas, NETL award number DE-FE0013163.

³The current development work is supported by the US Department of Energy National Energy Technology Laboratory under Award Number DE-FE0026422 (J. Figueroa, Program Manager).