Stable, asymmetric, tubular oxygen transport membranes of (Sc2O3)0.10(Y2O3)0.01(ZrO2)0.89 – LaCr0.85Cu0.10Ni0.05O3-δ

Abstract

Oxygen transport membranes have the potential to deliver pure and cheap oxygen to chemical reactors, combustors, gasifiers etc., given that geometry, microstructure and material properties are optimized. This work demonstrates the first successful preparation of dual-phase tubular, asymmetric oxygen transport membranes consisting of a new electronic conductor LaCr0.85Cu0.10Ni0.05O3-δ mixed with (Sc2O3)0.10(Y2O3)0.01(ZrO2)0.89 as ionic conductor. Challenges related to Cr-volatility were overcome by using Fe2O3 as a sintering aid. The sintering aid decreased mismatches in shrinkage and thermal expansion between the four layers in the asymmetric membrane and decreased the sintering temperature such that the Cr-volatility was suppressed. The membranes reached an oxygen flux of 0.28 ml∙min−1∙cm−2 in an air/N2 atmosphere at 950 °C. Furthermore, the membranes showed a stable oxygen flux after exposure to different atmospheres, including air/CO2 and air/H2 gradients. The successful fabrication of stable, asymmetric, tubular membranes opens the possibility for future integration in syngas or oxy-combustion applications.