Coupling of N2O decomposition with CO2 reforming of CH4 in novel cobalt-free BaFe0.9Zr0.05Al0.05O3- .DELTA. oxygen transport membrane reactor

Abstract Coupling of N 2 O decomposition with CO 2 reforming of CH 4 was demonstrated in cobalt-free perovskite BaFe 0.9 Zr 0.05 Al 0.05 O 3− δ (BFZ-Al) membrane reactor. Perovskite oxide BFZ-Al was synthesized by EDTA–citric acid complexing method. The stability of BFZ-Al and BaFe x Zr y Co 1− x − y O 3− δ (BFZ-Co) was studied under hydrogen atmosphere. X-ray diffraction analysis indicates that BFZ-Al shows a better stability compared to cobalt-based perovskite BFZ-Co. The oxygen permeation rate of BFZ-Al dense membrane was investigated from 810 to 960 °C, and the oxygen permeation rate reached 0.85 ml min −1  cm −2 at 960 °C. N 2 O decomposition in BFZ-Al membrane reactor was studied under three different sweep gas atmospheres including He, He/CH 4 , and He/CH 4 /CO 2 . Comparatively, a higher N 2 O conversion was achieved by using the sweep gas mixture He/CH 4 /CO 2 than only using He or He/CH 4 . Therefore, the simultaneous N 2 O decomposition and syngas production via dry reforming was studied in BFZ-Al membrane reactor by using N 2 O and He/CH 4 /CO 2 as feed gas and sweep gas, respectively. At 900 °C, almost complete N 2 O conversion was achieved owing to the efficient in situ removal of the inhibitor oxygen through BFZ-Al membrane. CH 4 conversion was found to be around 97% with 94% CO selectivity at 900 °C, and no obvious decline in the activity and selectivity was observed even after 100 h of the operation.