Poly(ionic liquid) membranes for CO2 separation from N2

Ting Song (Guest lecturer)

Activity: Talks and presentationsConference presentations


Carbon dioxide (CO2) can commonly be found in flue gas, natural gas streams, biogas and products of coal gasification[1]. Membrane separation is a promising technology for CO2 capture due to its energy efficiency, simple process design, low cost and environmental friendliness[2]. Recently, ionic liquids (ILs) have attracted great attention for their potential as alternative media for CO2 separation due to their unique properties[4]. Here we will present how poly(ionic liquids) membranes can combine the advantages of membranes and ILs to overcome the disadvantages of free ILs for CO2 capture [3].
According to previous investigations, imidazole-based ILs have excellent affinity for CO2. N-vinylimidazole was therefore used as a precursor for poly(IL) membranes for CO2 separation. By copolymerization of N-vinylimidazole and butyl acrylate the brittle nature of poly(vinylimidazole) was reduced and a flexible material suitable for membrane preparation was obtained. The copolymer, poly(vinylimidazole-co-butyl acrylate) (poly(V-co-B)), was crosslinked by use of alkyl halides at very simple conditions to prepare free standing membranes. The gas separation performance of the crosslinked membranes with different degrees of crosslinking was investigated. Here the CO2 permeability of the fully crosslinked membrane was 33.7 barrers with a CO2/N2 selectivity of 20.8, while the CO2 permeability was increased to 44.4 barrers with a similar selectivity of 21.6 for a 50% crosslinked membrane. The crosslinked poly(V-co-B) membrane has higher CO2 permeability without selectivity trade-off compared to a corresponding neat poly(ionic liquid) membrane[4].

[1] Y. Zhang, J. Sunarso, S. Liu, R. Wang, Current status and development of membranes for CO2/CH4 separation: A review, Int. J. Greenh. Gas Control. 12 (2013) 84–107.
[2] S. Rafiq, L. Deng, M.-B. Hägg, Role of Facilitated Transport Membranes and Composite Membranes for Efficient CO 2 Capture - A Review, ChemBioEng Rev. 3 (2016) 68–85.
[3] J. Deng, L. Bai, S. Zeng, X. Zhang, Y. Nie, L. Deng, S. Zhang, Ether-functionalized ionic liquid based composite membranes for carbon dioxide separation, RSC Adv. 6 (2016) 45184–45192.
[4] G. Zarca, W. J. Horne, I. Ortiz, A. Urtiaga, J. E. Bara, Synthesis and gas separation properties of poly(ionic liquid)-ionic liquid composite membranes containing a copper salt, J. Membrane Sci. 515 (2016) 109–114.

Period28 May 201830 May 2018
Event titleNordic Polymer Days 2018
Event typeConference
LocationCopenhagen, Denmark
Degree of RecognitionInternational