Cummins Inc.
System and method for managing contaminant storage in a storage catalyst

Abstract:

An internal combustion engine system includes an engine and an aftertreatment system that is connected to the engine to receive an exhaust flow from the engine. The aftertreatment system includes a contaminant storage catalyst for storing contaminants produced by the engine during cold start and low temperature operating conditions, and a NO.sub.x reduction catalyst downstream of the storage catalyst for receiving the contaminants released from the storage catalyst when temperature conditions in the exhaust flow and/or NO.sub.x reduction catalyst are above an effective temperature threshold for NO.sub.x reduction. A contaminant amount stored on the storage catalyst can be estimated in response to one or more operating parameters to manage a storage capacity of the storage catalyst. A bypass can used to bypass the storage catalyst to preserve storage capacity for a subsequent cold start condition.