(27e) High-Permeance Polymer-Functionalized Graphene Membranes That Surpass the Postcombustion Carbon Capture Target

Postcombustion carbon capture using high-performance CO₂-selective membranes has been identified as one of the most energy-efficient routes for reducing CO₂ emissions [1-3]. However, the capture performance, especially the permeance of the state-of-the-art membranes needs to be significantly increased to further improve the appeal of membranes for postconbustion capture, and importantingly, reduce the needed membrane area for separation because the capital cost of the membrane modules scales inversely with the permeance. Currently, with the exception of Polaris second generation membranes from Membrane Technology Research which yields a CO₂ permeance of 2000 GPU, there is no membrane technology that reaches the CO₂ permeance significantly higher than 1000 GPU, while maintaining a separation factor of 20 or above in the humid flue gas conditions. In this presentation, I will report a new class of sub-20-nm-thick organic-inorganic hybrid membranes, which we call as SPONG, comprising of nanoporous single-layer-graphene with a high porosity (up to 18.5%), functionalized with CO₂-phillic polymeric chains [4]. The hybrid membranes yield CO₂ permeance sixfold larger (6290 GPU) than the performance target while separating the CO₂/N₂ mixture mimicking flue gas streams with a separation factor well within the target. Overall, we report a number of membranes that yield CO₂ permeance up to 11790 GPU and CO₂/N₂ mixture separation factor up to 57.2. The hybrid membrane is conducive for scale-up because of its facile preparation involving simple coating steps.

References

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4. He, G., Huang, S., Villalobos, L. F., Zhao, J., Mensi, M., Oveisi, E., Rezaei, M., Agrawal, K. V. Submitted, under review (2019).