Thermal control and process optimization in methane partial oxidation with CO2 addition in catalytic membrane reactor

This work examines the influence of carbon dioxide on the partial oxidation of methane (POM) in a catalytic reactor equipped with a La0.5Sr0.5Fe0.9Mo0.1O3-delta membrane. A combined modeling approach using Gibbs energy minimization and the Wagner equation was employed to predict the thermal behavior and oxygen flux under varying flows of methane and CO2. The experimental results confirmed that adding CO2 reduces heat release in the reaction zone, improves thermal stability control, and helps maintain membrane integrity. The use of CO2 as a carrier gas in the reactor start-up mode was shown to improve the controllability of a targeted increase in the oxygen partial pressure gradient across the membrane, thereby reducing mechanical stress in it. Under operating conditions, although CO2 addition reduces CO selectivity slightly, it was shown that optimizing methane flow restores high selectivity levels (>90 %) while ensuring more stable thermal conditions. These findings suggest that CO2 addition, along with methane flow regulation, offers an efficient solution to improving both the thermal management and operational reliability of mixed ionic-electronic conducting membrane reactors.