Chemical Engineering Journal, Vol.305, 176-181, 2016
Coupling of N2O decomposition with CO2 reforming of CH4 in novel cobalt-free BaFe0.9Zr0.05Al0.05O3-delta oxygen transport membrane reactor
Coupling of N2O decomposition with CO2 reforming of CH4 was demonstrated in cobalt-free perovskite BaFe0.9Zr0.05Al0.05O3-delta (BFZ-Al) membrane reactor. Perovskite oxide BFZ-Al was synthesized by EDTA-citric acid complexing method. The stability of BFZ-Al and BaFexZryCo1-x-yO3-delta (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 degrees C, and the oxygen permeation rate reached 0.85 ml min(-1) cm(-2) at 960 degrees C. N2O decomposition in BFZ-Al membrane reactor was studied under three different sweep gas atmospheres including He, He/CH4, and He/CH4/CO2. Comparatively, a higher N2O conversion was achieved by using the sweep gas mixture He/CH4/CO2 than only using He or He/CH4. Therefore, the simultaneous N2O decomposition and syngas production via dry reforming was studied in BFZ-Al membrane reactor by using N2O and He/CH4/CO2 as feed gas and sweep gas, respectively. At 900 degrees C, almost complete N2O conversion was achieved owing to the efficient in situ removal of the inhibitor oxygen through BFZ-Al membrane. CH4 conversion was found to be around 97% with 94% CO selectivity at 900 degrees C, and no obvious decline in the activity and selectivity was observed even after 100 h of the operation. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:N2O decomposition;CO2 reforming;Oxygen transport membrane;Cobalt-free perovskite;Membrane reactor