The role of CuO modified La0·7Sr0·3FeO3 perovskite on intermediate-temperature partial oxidation of methane via chemical looping scheme

Abstract

Synthesis gas production via chemical-looping partial oxidation (CLPO) of methane reduces operating cost and likely avoids carbon dioxide emissions. Previous studies exhibit La0·7Sr0·3FeO3 (LSF) a good high-temperature oxygen carrier, but not being applicable in intermediate-temperature CLPO processes. This work proposes a CuO modified LSF (xCuO/LSF, x = 2,5,10,15) for enhancing the reactivity of oxygen carriers at relatively low temperatures. Characterization methods, including N2 physisorption, ICP-OES, H2-TPR, XRD and XPS, are implemented to determine properties of xCuO/LSF. Fixed-bed experiments determine the best candidate under 750 °C is 10CuO/LSF. The methane conversion rate of 10CuO/LSF is more than 3 times compared to that of unmodified LSF and the concentration of syngas increases by 375% with the H2/CO molar ratio of about 2.5. The regenerability of 10CuO/LSF proves to be good. This study provides a promising and simple way to lower the operating temperature of the CLPO process, likely leading a considerable energy saving.