TY - JOUR

T1 - High-flux CO2-stable oxygen transport hollow fiber membranes through surface engineering

AU - Buck, F.

AU - Bunjaku, O.

AU - Caro, J.

AU - Schiestel, T.

N1 - Funding Information: This work is part of the project “Plasma-induced CO 2 -conversion” (PiCK, project number: 03SFK2S3) and of the project “Next Generation Plasma Conversion” (NexPlas, project number: 03SF0618C) and financially supported by the German Federal Ministry of Education and Research in the framework of the “Kopernikus projects for the Energiewende”.

PY - 2022/4

Y1 - 2022/4

N2 - The influences of bulk diffusion and surface exchange on oxygen transport of (La0.6Ca0.4)(Co0.8Fe0.2)O3-δ (LCCF) hollow fiber membranes were investigated. As an outcome, two strategies for increasing the oxygen permeation were pursued. First, porous LCCF hollow fibers as support were coated with a 22 μm dense LCCF separation layer through dip coating and co-sintering. The oxygen permeation of the porous fiber with dense layer reached up to 5.10 mL min−1 cm-2 at 1000 °C in a 50 % CO2 atmosphere. Second, surface etching of dense LCCF hollow fibers with H2SO4 was applied. The surface etching of both inner and outer surfaces leads to a permeation improvement up to 86.0 %. This finding implies that the surface exchange reaction plays a key role in oxygen transport through LCCF hollow fibers. A good long-term (>250 h) stability of the asymmetric hollow fiber in a 50 % CO2 atmosphere was found at 900 °C.

AB - The influences of bulk diffusion and surface exchange on oxygen transport of (La0.6Ca0.4)(Co0.8Fe0.2)O3-δ (LCCF) hollow fiber membranes were investigated. As an outcome, two strategies for increasing the oxygen permeation were pursued. First, porous LCCF hollow fibers as support were coated with a 22 μm dense LCCF separation layer through dip coating and co-sintering. The oxygen permeation of the porous fiber with dense layer reached up to 5.10 mL min−1 cm-2 at 1000 °C in a 50 % CO2 atmosphere. Second, surface etching of dense LCCF hollow fibers with H2SO4 was applied. The surface etching of both inner and outer surfaces leads to a permeation improvement up to 86.0 %. This finding implies that the surface exchange reaction plays a key role in oxygen transport through LCCF hollow fibers. A good long-term (>250 h) stability of the asymmetric hollow fiber in a 50 % CO2 atmosphere was found at 900 °C.

KW - Asymmetric hollow fiber membrane

KW - Mixed ionic electronic conductor

KW - Oxygen separation

KW - Surface modification

UR - http://www.scopus.com/inward/record.url?scp=85120057110&partnerID=8YFLogxK

U2 - 10.1016/j.jeurceramsoc.2021.11.040

DO - 10.1016/j.jeurceramsoc.2021.11.040

M3 - Article

AN - SCOPUS:85120057110

VL - 42

SP - 1537

EP - 1547

JO - Journal of the European Ceramic Society

JF - Journal of the European Ceramic Society

SN - 0955-2219

IS - 4

ER -