Anion doping CO2-stable oxygen permeable membranes for syngas production

Abstract

For practical application in syngas production, the oxygen permeable membranes should possess both high oxygen permeation flux and good stability in harsh environment (CO2-containing reductive atmosphere). Under the premise of keeping stability, anion-doping method was applied to improve the oxygen permeability of the CO2-stable (Pr0.9La0.1)2.0(Ni0.74Cu0.21Ga0.05)O4+δ ((PL)2.0NCG) membrane. The developed (Pr0.9La0.1)2.0(Ni0.74Cu0.21Ga0.05)O4+δCl0.1 ((PL)2.0NCGCl0.1) exhibited three times higher oxygen permeation fluxes, similar CO2-tolerance and long-term stability compared with its parent one. Furthermore, the (PL)2.0NCGCl0.1 membrane was constructed to be used in reactors for the syngas production through partial oxidation of methane, which showed an oxygen permeation flux of 5 mL/min cm2, a methane conversion of 99.9%, and a CO selectivity of 97.5% at 900 °C, and no any degradation was observed during 100 h.