Enhancing CO 2 Transport Across a PEEK‐Ionene Membrane and Water‐Lean Solvent Interface
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- Pacific Northwest National Laboratory Battelle Blvd 99352 Richland WA USA
- Department of Chemical &, Biological Engineering University of Alabama 35487-0203 Tuscaloosa AL USA
- Pacific Northwest National Laboratory Battelle Blvd 99352 Richland WA USA, Present address: Oak Ridge National Laboratory 37830 Oak Ridge TN USA
- Pacific Northwest National Laboratory Battelle Blvd 99352 Richland WA USA, Washington State University 99164-1067 Pullman WA USA
Abstract Efficient direct air capture (DAC) of CO 2 will require strategies to deal with the relatively low concentration in the atmosphere. One such strategy is to employ the combination of a CO 2 ‐selective membrane coupled with a CO 2 capture solvent acting as a draw solution. Here, the interactions between a leading water‐lean carbon‐capture solvent, a polyether ether ketone (PEEK)‐ionene membrane, CO 2 , and combinations were probed using advanced NMR techniques coupled with advanced simulations. We identify the speciation and dynamics of the solvent, membrane, and CO 2 , presenting spectroscopic evidence of CO 2 diffusion through benzylic regions within the PEEK‐ionene membrane, not spaces in the ionic lattice as expected. Our results demonstrate that water‐lean capture solvents provide a thermodynamic and kinetic funnel to draw CO 2 from the air through the membrane and into the bulk solvent, thus enhancing the performance of the membrane. The reaction between the carbon‐capture solvent and CO 2 produces carbamic acid, disrupting interactions between the imidazolium (Im + ) cations and the bistriflimide anions within the PEEK‐ionene membrane, thereby creating structural changes through which CO 2 can diffuse more readily. Consequently, this restructuring results in CO 2 diffusion at the interface that is faster than CO 2 diffusion in the bulk carbon‐capture solvent.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1975137
- Alternate ID(s):
- OSTI ID: 1983414
- Journal Information:
- ChemSusChem, Journal Name: ChemSusChem Journal Issue: 13 Vol. 16; ISSN 1864-5631
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
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