| abstract |
A ceramic membrane element for an oxygen separator is formed from a ceramic material represented by the structure:whereA is a lanthanide element;A' is a suitable lanthanide element dopant;B is selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zinc and mixtures thereof;B' is copper;x is between 0.4 and 0.8;y is between 0.1 and 0.9; andz is>0 (and determined by stoichiometry).When B includes cobalt in an amount greater than 0.1, the included iron content is less than 0.05.The membrane element selectively transports oxygen ions therethrough at a relatively low temperature, with a flux detected at about 600° C. This enables the oxygen separator to be operated at lower temperatures than convention separators that frequently have operating temperatures in excess of 900° C. Mechanical stability may be enhanced by the addition of a second phase to the ceramic. |