2024 AIChE Annual Meeting

(659e) Thermally Crosslinked Polymer of Intrinsic Microporosity Membranes for CO2 Separation

Author

Canghai Ma - Presenter, Lawrence Berkeley National Laboratory
Polymers of intrinsic microporosity (PIMs) have seen a growing role in CO2 separation membranes. However, conventional PIM membranes faces two primary challenges: 1) the moderate CO2 selectivity of PIM membrane limits the effective separation of CO2; 2) PIM polymer chain segments undergo swelling and plasticize under high CO2 feed pressures, leading to a substantial decline in gas selectivity and the loss of separation efficiency. To address these challenges, this presentation focuses on the molecular design of PIMs to establish thermally cross-linked polymer networks to enhance the CO2 selectivity and plasticization resistance of PIM membranes. Specifically, PIM-1 undergoes hydrolysis to form carboxylated PIM-COOH polymers, followed by esterification to produce monoesterified PIM. These monoesterified PIMs are then thermally ester-crosslinked at various temperatures and durations. Membranes treated at 300°C for 8 h exhibit a CO2 permeability of 7421 Barrers, with a CO2/N2 selectivity of 19.2, significantly surpassing the latest Robeson upper bound. Additionally, the crosslinked membranes demonstrate notably improved CO2 plasticization resistance, enduring pressures up to 42 bar, in comparison to their uncrosslinked counterparts. Other approaches, such as ring-opening, hydrogen bonding, and multi-covalent cross-linking, will also be explored and discussed. The discoveries from these research hold promise for application in critical areas of CO2 separation, such as natural gas purification and flue gas CO2 capture.

References

[1] J. Zhang, Y. Sun, F. Fan, Q. Zhao, G. He, C. Ma*, J. Membr. Sci. 2023, 122115.

[2] L. Wu, X. Chen, Z. Zhang, S. Xu, C. Ma*, N. Li*, J. Membr. Sci., 2021, 634, 119399

[3] X. Chen, Y. Fan, L. Wu, L. Zhang, D. Guan, C. Ma*, N. Li*., Nat. Commun., 2021, 12, 6140