Unsteady-state permeation and surface exchange of dual-phase membranes

A CO2-stable reduction-tolerant Nd-containing dual phase membrane for oxyfuel CO2capture

“…On the other hand, the steady time is related to the dual phase material or composition ratio. This behaviour has been reported in many dual phase membranes, such as x wt% Fe 2 O 3Àd -(100 À x) wt% Ce 0.9 Gd 0.1 O 2Àd (x ¼ 25, 40, 50), 21 35 As shown in Fig. 4a, the oxygen permeation uxes through all of our dual phase membranes increase with increasing temperature.…”

Comparative investigation of dual-phase membranes containing cobalt and iron-based mixed conducting perovskite for oxygen permeation

“…All the dualphase composite oxides contain a fluorite phase and a perovskite phase, and no impurities. That is to say, the two phases are chemically compatible with each other as reported in our previous investigations [45][46][47][48][49][50][51]. For the cobalt-containing dual-phase membranes, the diffraction peaks strength of SCC perovskite is very weak and only the diffraction peaks at 33.61, 48.31 and 60.31 can be detectable, which indicates that few perovskite grains are exposed on surfaces of the as-prepared membranes.…”

“…However, perovskite membranes without alkaline earth elements doping in A-site have high stability under CO 2 atmosphere but much low permeation fluxes [43,44]. Recently, our group reported a series of dual-phase membranes made of fluorite-type oxygen ionic conductors and perovskitetype mixed conductors [45][46][47][48][49][50]. The oxygen ionic conductor is in charge of the transport of oxygen ions and the mixed conductor is in charge of the transport of both oxygen ions and electrons.…”

Design and experimental investigation of oxide ceramic dual-phase membranes

“…Adjustment of membrane bulks was usually accounted for the above unsteady stage phenomenon. However, we have verified that the unsteady permeation is related to surface exchange of oxygen on both sides of dual-phase membranes, and this unsteady stage can be avoided by coating an oxygen reducing catalyst, such as La 0.6 Sr 0.4 CoO 3 , on both sides of the membrane [54]. The time dependence of the SDC-SSF(Cr) oxygen permeation flux is plotted in Fig.…”

“…9, regardless of whether the air side or both sides are coated with LSC. If there is no oxygen reducing catalyst on the both sides, it usyally takes more than 50 h to reach the steady state, and the resultant steady state flux is lower than those of membranes coated with La 0.6 Sr 0.4 CoO 3 on one side or both sides [54].…”