THIN-FILM MANUFACTURING OF INORGANIC OXYGEN TRANSPORT MEMBRANES BY PHYSICAL VAPOR DEPOSITION

Keywords: oxygen transport membrane, physical vapor deposition Gases with high oxygen content or even pure oxygen can be used in certain future power plants for the combustion process (e.g. so-called OXYFUEL process), or in e.g. production processes in glass and cement industry. Inorganic membrane systems are considered as an efficient way to separate oxygen from air. It is evident that – as long as materials with extremely high oxygen permeation are not available – high oxygen fluxes through a membrane require thin membranes. This paper discusses the manufacturing of thin inorganic oxygen transport membranes by physical vapor deposition (PVD). After a short review of the technology in general, the focal point of the presentation are ion-assisted techniques for the deposition of ceria-, zirconia- and perovskite-based oxygen transport membranes. Ion-assisted processes lead to layers with high density but also to higher compressive stresses, which the entire arrangement has to sustain. As a major finding from the experiments, a balancing of layer density and mechanical stress is necessary. Moreover, it is illustrated that the surface morphology of the substrate crucially determines the morphology of the PVD layers