A CO sub(2)-stable reduction-tolerant Nd-containing dual phase membrane for oxyfuel CO sub(2) capture

We report a novel CO sub(2)-stable reduction-tolerant dual-phase oxygen transport membrane 40 wt% Nd sub(0.6)Sr sub(0.4)FeO sub(3- delta )-60 wt% Ce sub(0.9)Nd sub(0.1)O sub(2- delta ) (40NSFO-60CNO), which was successfully developed by a facile one-pot EDTA-citric sol-gel method. The microstructure of the crystalline 40NSFO-60CNO phase was investigated by combined in situ X-ray diffraction (XRD), scanning electron microscopy (SEM), back scattered SEM (BSEM), and energy dispersive X-ray spectroscopy (EDXS) analyses. Oxygen permeation and long-time stability under CO sub(2) and CH sub(4) atmospheres were investigated. A stable oxygen flux of 0.21 cm super(3) min super(-1) cm super(-2) at 950 degree C with undiluted CO sub(2) as sweep gas is found which is increased to 0.48 cm super(3) min super(-1) cm super(-2) if the air side is coated with a porous La sub(0.6)Sr sub(0.4)CoO sub(3- delta ) (LSC) layer. All the experimental results demonstrate that the 40NSFO-60CNO not only shows good reversibility of the oxygen permeation fluxes upon temperature cycling, but also good phase stability in a CO sub(2) atmosphere and under the harsh conditions of partial oxidation of methane to synthesis gas up to 950 degree C.