A novel CO2-resistant ceramic dual-phase hollow fiber membrane for oxygen separation

Abstract

Robust oxygen permeable ceramic membranes have potential applications in clean energy industries like oxyfuel power plants and green chemical synthesis like syngas production combining the separation and reaction in one unit. The well-known and 1 These authors contributed equally to this work and should be considered co-first authors without any noticeable performance degradation or membrane deterioration. By contrast, the flux rate of pure perovskite membrane had been sharply dropped down by 80% albeit operated for only 8 hours.

Highly Stable Dual‐Phase Membrane Based on Ce0.9Gd0.1O2–δ—La2NiO4+δ for Oxygen Permeation under Pure CO2 Atmosphere

“…Noble metals, perovskite, or Ruddlesden–Popper‐type oxides are usually used as the electronic or mixed ionic–electronic conductors, whereas fluorite‐type oxides are used as ionic conductors . However, the A sites of the perovskite phase (ABO 3 ) are often occupied by alkaline earth metals, which can be easily eroded by CO 2 to form carbonates.…”

“…In this regard, oxides with transitional metals and/or lanthanides display a certain potential because of their tolerance against CO 2 . For instance, higher oxygen permeability and enhanced CO 2 resistance can be simultaneously achieved in Ce 0.8 Gd 0.2 O 2 —CoFe 2 O 4 , SrFeO 3 —Ce 0.84 Gd 0.16 O 2 , NiFe 2 O 4 —Ce 0.8 Gd 0.2 O 2– δ , and Pr 0.1 Gd 0.1 Ce 0.8 O 2 —CoFe 2 O 4 dual‐phase membranes. La 2 NiO 4+ δ (LNO) is more robust than most perovskite oxides and spinal oxides as membrane materials, but limited by the oxygen flux due to the low ionic conductivity.…”

A novel heterogeneous La0.8Sr0.2CoO3−δ/(La0.5Sr0.5)2CoO4+δ dual‐phase membrane for oxygen separation

“…Dual phase membrane, where a continuous electronic conducting phase is interspersed by a continuous ionic conducting phase, has been developed to surpass the electronic conductivity limitation of an ionic conducting phase while retaining high structure stability advantage of ionic conducting phase . Such a concept can also be applied to enlarge the TPBs from hetero‐interface (i.e., contact areas between the oxygen gas, oxygen ions, and electrons) to larger areas across the membrane surface …”

“…19 Dual phase membrane, where a continuous electronic conducting phase is interspersed by a continuous ionic conducting phase, has been developed to surpass the electronic conductivity limitation of an ionic conducting phase while retaining high structure stability advantage of ionic conducting phase. 14,21 Such a concept can also be applied to enlarge the TPBs from hetero-interface (i.e., contact areas between the oxygen gas, oxygen ions, and electrons) to larger areas across the membrane surface. 4,13,14 Here, we report the characterizations of the Ruddlesden-Popper (La 0.5 Sr 0.5 ) 2 9,13,20,22,23 Scheme 1 illustrates the conceptual advantage obtained by shifting from surface decorated hollow fiber to dual-phase hollow fiber.…”

Selection of oxygen permeation models for different mixed ionic‐electronic conducting membranes

“…24,25 Membrane configurations were also broadly studied in recent years, especially on single-channel and multichannel hollow fiber membranes. 4,26,27 At the same time, some researchers are trying to disclose the oxygen permeation mechanism and build permeation models to describe the oxygen permeation process. [28][29][30][31][32][33][34][35] With the help of a proper oxygen permeation model, the oxygen exchange kinetics, diffusion kinetics and degradation mechanism can be well understood for MIEC membranes.…”