Exhaust Aftertreatment for NOX-Containing Exhaust from an Internal Combustion Engine: 8,857,154

A method of treating NOx-containing exhaust from an internal combustion engine. An exhaust aftertreatment system has the following devices arranged in the following order downstream the exhaust manifold: a lean NOx trap (LNT), a particulate filter (PF) and a selective reduction catalyst (SCR) device. At least the LNT is located in the engine compartment. The SCR temperature at the input to, or in, the SCR is monitored to determine whether the aftertreatment system is to be operated in a cold mode or warm mode. Only during warm mode is reductant provided to the SCR, and during warm mode the LNT is not regenerated.