Oxygen separation with mixed conducting ceramic membranes - application potential and state of the art

摘要

Mixed conducting ceramic membranes possess an enormous application potential for efficient high temperature separation of oxygen from air. However, the known materials are characterized by different disadvantages like a low oxygen permeability or bad chemical and mechanical stability. Moreover, the complex interactions between material properties and application conditions complicates the material development. Therefore, the development of materials and ceramic components was oriented on Ca_(1-x)Sr_xFe_(1-y)Mn_yO_(3-δ)??with high chemical and mechanical stability and on Ba_(1-x)Sr_xCo_(1-y)Fe_yO_(3-δ)??with high permeability but much lower stability. The former system was predestinated for asymmetric membranes consisting of thin dense layers on porous supports, the latter one has to be protected against chemical attack. Selected results of the development of ceramic components will be presented in context with the relevant material properties.