Patent ID: 8069654

Claim:
A method of operating a diesel power generation system, comprising: operating a diesel engine to produce lean NO x -containing exhaust, wherein the diesel engine has a maximum displacement that is at least about 4 liters; channeling at least the bulk of the exhaust from the diesel engine through one or more fuel reformers; channeling the exhaust from the one or more fuel reformers through one or more LNTs containing rhodium; initiating a lean warm-up phase in which fuel is injected into at least a portion of the exhaust downstream from the engine in such a manner that the injected fuel combusts in at least one of the fuel reformers under lean conditions, heating the fuel reformer; initiating a rich regeneration phase in which fuel is injected into the exhaust in such a manner that the exhaust within the at least one fuel reformer is net rich, whereby a significant portion of the injected fuel undergoes steam reforming in the at least one fuel reformer and the at least one fuel reformer produces a reformate-containing exhaust that regenerates at least one of the LNTs; wherein at least about 80% of the stored NO x removed from the LNTs during the rich regeneration phase is converted to products selected from the group consisting of N 2 and NH 3 ; wherein the regeneration takes place with the at least one LNT at an initial temperature of about 275Â° C. or less; the fuel reformers collectively have no more than about 0.5 grams rhodium per liter maximum displacement of the diesel engine; the fuel reformers comprises effect amounts of precious metal catalyst for catalyzing steam reforming at 600Â° C.; the reformate-containing exhaust comprises at least about a 3:2 hydrogen to carbon monoxide ratio; and the total rhodium content of the fuel reformers collectively is between 1.5 and 4 times the total rhodium content of the LNTs collectively.