Thursday, November 11, 2010: 3:57 PM
251 D Room (Salt Palace Convention Center)
Dense oxygen-permeable ceramic membranes have been explored as an alternative oxygen source for carbon dioxide reforming of methane to syngas (CO+H2). In this study, the effects of various parameters on syngas production over a dense Ba0.5Sr0.5Co0.8Fe0.2Ox (BSCF) membrane have been investigated. These parameters include catalysis type, reaction temperature, membrane thickness, pH, and feed concentration. Although Pt-Ni/Al2O3 catalyst shows high methane conversion in the presence of the BSCF membrane at 800°C, the activity of this catalyst is low at 600°C. Pt-Ni/CeZrO2 bimetallic catalyst demonstrates superior performance compared to Pt-Ni/Al2O3 catalyst at 600°C. The BSCF membrane can reduce the apparent activation energy of CO2 reforming reaction by changing the reaction pathway. The BSCF membrane with low thickness demonstrates a higher methane conversion and H2:CO ratio than BSCF membrane with high thickness because membrane oxygen flux is inversely proportional to thickness. Varying the pH of the precursor solution during membrane preparation has no significant effect on the oxygen flux or the reaction. The CH4:CO2 feed ratio significantly affects the hydrogen production over the BSCF membrane. Altering the CH4:CO2 ratio has a direct impact on the oxygen flux, which in turn can influence the reaction pathway. These studies suggest that Pt-Ni/CeZrO2 catalyst might be suitable for low-temperature hydrocarbon conversion reactions over low-thickness BSCF ceramic membranes.