Effect of the Catalyst Bed Configuration on the Partial Oxidation of Liquid Hydrocarbons

Rh-substituted pyrochlores have been shown to be excellent diesel reforming catalysts. However, it is desirable to reduce the amount of this expensive material while maintaining an acceptable level of hydrogen production. This study demonstrates that a segmented catalyst bed approach can be used to achieve this objective. Two strategies were examined: (1) promotion of the indirect reforming mechanism with a combustion catalyst in the reactor inlet, followed by a reforming catalyst, and (2) placement of catalysts in regions of the reactor that have conditions in which they are less likely to deactivate. The first approach demonstrated that a Ni-substituted barium hexaaluminate catalyst can be used in the reactor inlet to promote combustion with a Rh-substituted pyrochlore in the reactor outlet, but the combustion catalyst should fill less than 50% of the reactor. The second approach showed a benefit in the use of a sulfur-tolerant noble metal catalyst in the reactor outlet and that a significant portion of the carbon formed on the Ni-substituted pyrochlore is located in the last 25% of the catalyst bed.