Patent ID: 7810315

Claim:
A method of operating a power generation system, comprising: operating a diesel engine to produce exhaust comprising NO x ; passing at least a portion of the exhaust from the engine to a lean NO x trap through a fuel reformer; adsorbing NO x from the exhaust under lean conditions using the lean NO x trap; preparing to regenerate the lean NO x trap by heating the fuel reformer by at least 100° C. to a temperature of at least about 500° C. by injecting fuel at rates that leave the exhaust entering the fuel reformer lean, while at times limiting the fuel injection rates to limit the amount of NO x that slips from the lean NO x trap; and wherein limiting the fuel injection rates to limit the amount of NO x that slips from the lean NO x trap comprises either: (a) setting the fuel injection rate to an upper limit determined by a relationship between fuel injection rate and hydrocarbon slip from the fuel reformer or NO x slip from the lean NO x trap; or (b) adjusting the fuel injection rate based on measurements of hydrocarbon slip from the fuel reformer or NO x slip from the lean NO x trap.