International Journal of Hydrogen Energy, Vol.38, No.11, 4483-4491, 2013
La0.6Sr0.4Co0.8Ni0.2O3-delta hollow fiber membrane reactor: Integrated oxygen separation - CO2 reforming of methane reaction for hydrogen production
An integrated reactor system which combines oxygen permeable La0.6Sr0.4Co0.8Ni0.2O3-delta (LSCN) perovskite ceramic hollow fiber membrane with Ni based catalyst has been successfully developed to produce hydrogen through oxy-CO2 reforming of methane (OCRM). Dense La0.6Sr0.4Co0.8Ni0.2O3-delta hollow fiber membrane was prepared using phase inversion-sintering method. OCRM reaction was tested from 650 degrees C to 800 degrees C with a quartz reactor packed with 0.5 g Ni/Al2O3 catalyst around the LSCN hollow fiber membrane. CH4 and CO2 were used as reactants and air as the oxygen source was fed through the bore side of the hollow fiber membrane. In order to gauge the effectiveness of this membrane reactor system, air flow was closed at 800 degrees C and dry reforming of methane (DRM) was tested for comparison. The results show that the oxygen fluxes of LSCN membrane swept by helium are nearly 3 times less than those swept by OCRM reactants. With increasing temperature and oxygen supply, methane conversion in the OCRM reactor reaches 100%, but CO2 conversion decreases from 87% to 72% due to the competition reaction with POM. CO selectivity is as high as nearly 100% at reaction temperatures of 700 degrees C-800 degrees C while H-2 selectivity reaches a maximum of 88% at 700 degrees C. At 800 degrees C, when air supply was closed and DRM was conducted for comparison, CO selectivity decreased to 91%, resulting in carbon deposition which was around 4 times more than those obtained under OCRM reaction and H-2/CO ratio decreased from 0.93 to 0.74, showing better carbon resistance and higher H-2 selectivity of the Ni-based catalyst over the integrated oxygen separation-OCRM reaction across the LSCN hollow fiber membrane reactor. Copyright (c) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Oxy-CO2 reforming of methane (OCRM);Integrated catalytic hollow fiber membrane reactor;La0.6Sr0.4Co0.8Ni0.2O3-delta perovskite membrane;Hydrogen production