Nature – Metcalfe et al. (2024): Separation and concentration of CO2 from air using a humidity-driven molten-carbonate membrane

Ian S. Metcalfe, Greg A. Mutch, Evangelos I. Papaioannou, Sotiria Tsochataridou, Dragos Neagu, Dan J. L. Brett, Francesco Iacoviello, Thomas S. Miller, Paul R. Shearing, Patricia A. Hunt IN: Nat energy, 2024, https://doi.org/10.1038/s41560-024-01588-6

Here the Authors report a molten-carbonate membrane that can ‘pump’ CO₂ from a 400 ppm input stream (representative of air) to an output stream with a higher concentration of CO₂, by exploiting ambient energy in the form of a humidity difference. The substantial H₂O concentration difference across the membrane drives CO₂ permeation ‘uphill’ against its own concentration difference, analogous to active transport in biological membranes.

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