Partial oxidation of methane and oxygen permeation in SrCoFeO_x membrane reactor with different catalysts

Partial oxidation of methane (CH₄) and oxygen permeation in a dense SrCoFeO_x disk membrane reactor were studied with the reducing side of the membrane packed with different catalysts (catalyst support γ-Al₂O₃, La_0.6Sr_0.4Co _0.8Fe_0.2O_{3- δ}, and 10 wt% Ni/γ-Al₂O₃) of increasing reaction activities for CH₄ oxidation. The influence of temperature, flow rates, and inlet CH₄ concentration (diluted with helium) on the performance of the different membrane reactors was investigated. The oxygen permeation flux and CH₄ conversion increased in the following order: γ-Al ₂O₃ < La_0.6Sr_0.4Co _0.8Fe_0.2O_{3- δ} < 10% Ni/γ-Al ₂O₃. The membrane reactor with the reforming catalyst of 10 wt% Ni/γ-Al₂O₃ had the highest CH₄ conversion (∼90%), CO selectivity (97%), and oxygen permeation flux (2.40 mL/(cm² min)) at 900 °C. The improvement of the oxygen permeation through the membranes with different catalysts emphasizes the effect of the CH₄ oxidation reaction rate on the reducing side of the membrane on the oxygen permeation flux through the mixed-conducting ceramic membranes. Under identical conditions, the oxygen permeation flux through mixed-conducting ceramic membrane with a reducing gas is a strong function of the catalytic activity for the oxidation of the reducing gas.