Oxygen transport membranes based on ceramic composites

Dense ceramic oxygen transport membranes (OTMs) combining high oxygen flux with chemical and mechanical stability find numerous applications in industrial processes where oxygen is extracted from air. In the present publication, Sintef Industry and The Electrochemistry group at SMN have collaborated in a project financed by the Research Council of Norway (CLIMIT 268450) rationalizing the performance limitation of OTMs based on state-of-the-art ceramic composite system.

J. Membrane Sci. 660, 120875 (2022).

Illustration of the principle of oxygen gas separation with ceramic mixed conducting composites: Oxygen gas at the membrane feed side approaches the composite surface, oxide ions and electrons diffuse separately in the two ceramic phases through the dense membrane, and eventually recombine into the opposite permeate side of the membrane.

Illustration of the principle of oxygen gas separation with ceramic mixed conducting composites: Oxygen gas at the membrane feed side approaches the composite surface, oxide ions and electrons diffuse separately in the two ceramic phases through the dense membrane, and eventually recombine into the opposite permeate side of the membrane.

Cubic bismuth oxide (δ-Bi2O3) exhibits the highest reported oxide ion conductivity among binary oxides. Paired with the excellent electronic conductor (La0.8Sr0.2)0.99MnO3-δ (LSM), Tm-stabilised δ-Bi2O3 (BTM) and LSM form state-of-the-art ceramic composite oxygen transport membranes. The present contribution addresses the surface and bulk properties of the BTM-LSM materials system to determine the limiting factors for the oxygen permeation across the membrane. We seek to optimize the performance by improving the microstructure and varying the BTM/LSM volume ratio. To examine the potential of stabilized δ-Bi2O3 as a single-phase OTM, we introduce mixed conductivity in BTM by substituting some of the Tm with Pr. Flux measurements were performed as a function of temperature and oxygen partial pressure gradient and oxygen exchange coefficients were determined by means of oxygen isotope based approaches.

Emhjellen, L. K., Xing, W., Li, Z. & Haugsrud, R. (2022). Oxygen permeability and surface kinetics of composite oxygen transport membranes based on stabilized δ-Bi2O3. Journal of Membrane Science, Volume 660 (120875), 2-6. https://doi.org/10.1016/j.memsci.2022.120875.

By Reidar Haugsrud
Published Apr. 11, 2023 9:02 AM - Last modified Nov. 28, 2023 10:37 AM
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