Papers by Keyword: Oxygen Separation

Abstract: ReBaCo₂O_5+δ (Re=Pr, Nd, Y) oxides were synthesized by solid state reaction method. The oxygen permeation flux of ReBaCo₂O_5+δ (Re=Pr, Nd, Y) membranes increased with temperature and oxygen partial pressure and ranked as follow: PrBaCo₂O_5+δ > NdBaCo₂O_5+δ > YBaCo₂O_5+δ. The oxygen permeation response of PrBaCo₂O_5+δ membrane was fairly stable and no detectable degradation is observed at high temperature under carbon dioxide conditions (CO₂ = 500 ppm).

Abstract: Thin films of oxygen-conducting materials are expected to exhibit enhanced oxygen permeability, due to their reduced diffusion path. Two such materials, yttria-stabilised zirconia (YSZ) and ceria gadolinium oxide (CGO), were deposited onto anodic alumina substrates by electron beam evaporation of the parent materials. Continuous films 200-400 nm thick were characterised through SEM and XRD analysis. It was found that the substrate temperature during deposition strongly influenced the structure and stability of the films, with the original simple cubic structure being retained at deposition temperatures above 450 °C. Attempts to deposit thin films of a yttria-doped SrCoO_3-δ perovskite were unsuccessful, due to melting of the material during deposition and thermal diffusion into the substrate.

Abstract: As the oxygen permeation flux of La0.7Sr0.3Ga0.6Fe0.4O3-δ (LSGF) membranes is lower than commercial membranes, we coated the nano porous La0.6Sr0.4CoO3-δ (LSC) particles to enhance the oxygen permeation flux. The nano porous LSC particles were synthesized in an advanced process to increase the volume fraction of nano pores by ultrasonic spray pyrolysis. The synthesized LSC particles consisted of nano sized primary particles and pores. They also had remarkably high surface area (22 m2/g). It was found that the LSGF membrane coated by the nano porous LSC resulted in significant improvement in the oxygen permeability.