Ring Opened Heterocycles: Promising Ionic Liquids for Gas Separation and Capture

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Journal of Membrane Science

DOI:https://doi.org/10.1016/j.memsci.2012.01.042· OSTI ID:1036574

Mahurin, Shannon Mark ^[1]; Yeary, Joshua S ^[1]; Baker, Sheila N ^[1]; Jiang, Deen ^[1]; Dai, Sheng ^[1]; Baker, Gary A ^[1]

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1. ORNL

We report on a new class of highly fluid ionic liquids integrating a cation that resembles an opened imidazolium structure with two distinct anions, bis(trifluoromethylsulfonyl)imide, [Tf{sub 2}N], and a nitrile-containing anion, [C(CN)3]. These new ionic liquids show exceptional CO{sub 2} permeability values in liquid membrane gas separations with results that equal or exceed the Robeson upper bound. Moreover, these ionic liquids offer ideal CO{sub 2}/N{sub 2} selectivities competitive with the best results reported to date, exhibiting values that range from 28 to 45. The nitrile containing ionic liquid displayed the highest ideal CO{sub 2}/N{sub 2} selectivity with a value of 45 which primarily results from a reduction in the nitrogen permeability. In addition to permeability results, CO{sub 2} solubilities were also measured for the this new class of ionic liquids with values similar to the popular 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. The CO{sub 2} solubility results were compared to predicted values obtained using both a modified regular solution theory and the quantum chemical Conductor-like Screening Model for Real Solvents (COSMO-RS) method. Agreement between predicted and measured solubility values is also discussed.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1036574
• Journal Information: Journal of Membrane Science, Journal Name: Journal of Membrane Science Vol. 401-402; ISSN 0376-7388; ISSN JMESDO
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ANIONS
CATIONS
MEMBRANES
MOLTEN SALTS
NITRILES
NITROGEN
PERMEABILITY
SOLUBILITY
SOLVENTS