2019 AIChE Annual Meeting

(558aw) High Performance Cobalt-Based IL/PIM-1 Thin Film Composite Membrane for Air Separation

Authors

Han, J. - Presenter, Institute of Process Engineering, Chinese Academy of Sciences
Bai, L., Institute of Process Engineering, Chinese Academy of Sciences
Zhang, X., Institute of Process Engineering, Chinese Academy
Luo, S., Beijing Key Laboratory of Ionic Liquids Clean Process,CAS Key Labroratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences
Air separation is an important process in producing oxygen-enriched air or nitrogen-enriched air, and it has found wide application in industrial combustion and food preservation. Compared with cryogenic distillation and pressure swing adsorption, membrane-based air separation has attracted substantial attention due its inherent advantages of low cost, energy conservation and simple maintenance. However, the development of air separation membranes is frequently challenged by the trade-off between permeability and selectivity due to the close molecule sizes of O2 (0.346 nm) and N2 (0.364 nm). Facilitated transport membrane containing O2 carriers, which can selectively and reversibly react with O2 and thus facilitate O2 transport in membranes. Cobalt-based ionic liquid (Co-IL) is an efficient O2 carrier and drawing much attention.1

In this study, thin film composite (TFC) membranes were prepared using polymer of intrinsic microporosity (PIM-1)2 as the matrix and Co-IL (Bmim2Co(SCN)4, Bmim2CoCl4, Bmim2Co(NO3)4) as the carrier. The composite membranes were characterized by SEM, FTIR, XRD, and gas permeation properties. SEM images revealed uniform and thin films (<1 μm) were fabricated. The FTIR spectra indicated the interaction between Co-IL and PIM-1 is physical. Meanwhile, the membranes exhibited outstanding air separation performance. The addition of a certain amount of Co-IL can improve the gas permeance and O2/N2 selectivity. Meanwhile, decreasing the feed pressure can further enhance the separation performance. The composite membranes with 0.4 wt% Bmim2Co(SCN)4 showed a O2 permeance of >420 GPU and O2/N2 selectivity of >6, respectively, making them attractive for air separation.

References

  1. Matsuoka, A.; Kamio, E.; Mochida, T.; Matsuyama, H., Facilitated O2 transport membrane containing Co(II)-salen complex-based ionic liquid as O2 carrier. J Membrane Sci 2017, 541, 393-402.
  2. Liang, C. Z.; Liu, J. T.; Lai, J. Y.; Chung, T. S., High-performance multiple-layer PIM composite hollow fiber membranes for gas separation. J Membrane Sci 2018, 563, 93-106.