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DOE OSTI · 2370495

Amine functionalized supported ionic liquid membranes (SILMs) for CO 2 /N 2 separation

Chamoun-Farah, Antoine·Keller, Austin N.·Balogun, Mariam Y.·Cañada, Louise M.·Brennecke, Joan F.·Freeman, Benny D.
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Abstract

Supported ionic liquid membranes (SILMs), containing aprotic N-heterocyclic anion ionic liquids (AHA ILs) in an inorganic inert support, exhibit CO 2 /N 2 permselectivity values as high as 640 at 35.0 °C and 0.03 bar CO 2 , which represents conditions similar to post-combustion carbon capture (PCCC) from a natural gas power plant. A Fickian model fit to the experimental data estimates CO 2 permeability at direct air capture (DAC) conditions of 10,400 barrer and a CO 2 /N 2 permselectivity of 4000 for the best performing IL, triethyl(octyl)phosphonium 4-bromopyrazolide ([P 2228 ][4-BrPyra]). The most important criterion for high selectivity is a large equilibrium constant for binding between the IL and CO 2 , which results in high CO 2 solubility. ILs with smaller molar volumes and with no fluoroalkyl chains enhance N 2 rejection. As a result, low viscosity and high IL molar density also enhance CO 2 /N 2 permselectivity and CO 2 permeance.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYamine functionalizationgas seperationionic liquidssupported ionic liquid membranes

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Chamoun-Farah, Antoine, Keller, Austin N., Balogun, Mariam Y., Cañada, Louise M., Brennecke, Joan F., Freeman, Benny D.. 2024-04-15. Amine functionalized supported ionic liquid membranes (SILMs) for CO 2 /N 2 separation. https://doi.org/10.1016/j.memsci.2024.122758

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