(343i) Reactor Design for Diesel Reforming Using a Graded-Composition Monolith

An NETL-developed Rh-substituted pyrochlore catalyst successfully reformed pump diesel into a H₂- and CO-rich synthesis gas for over 1000 hrs with no signs of deactivation. Even with an already low level of precious metal loading, the possibility of decreasing catalyst cost was later demonstrated using a graded catalyst bed approach.  These demonstrations were performed using catalyst powders. In order to develop a commercially representative catalyst, this study examined the application of Rh-, and less expensive Ni- and Ru-substituted pyrochlore catalysts deposited onto alumina foam monoliths. The catalyst coated monoliths were placed into the reactor in several different configurations to examine the performance of a graded monolith under the catalytic partial oxidation (CPOX) of a diesel surrogate fuel. Catalytic testing was followed by carbon characterization of the individual coated foams using temperature programmed oxidation (TPO). This approach allowed for quantification of carbon formation on each catalyst in different sections of the reactor during CPOX experiments. The results of this study confirmed the trends observed in the previous powder studies and explored additional combinations of catalyst compositions in the different reaction zones of the reactor. Further it demonstrated the viability of applying the graded-composition approach to a commercially structured monolithic reactor.