Device for reducing nox emission in a diesel engine system

Abstract

A device is provided for reducing NOx emission in the engine exhaust stream for a Diesel engine system. The engine system including, but not limited to an exhaust line having at least a Diesel Oxidation Catalyst (DOC), a Diesel Particulate Filter (DPF) and a Selective Catalyst Reduction (SCR) system. Inside the Diesel Particulate Filter (DPF) a NOx absorber is provided and the NOx absorber being suitable to store the NOx at low temperature and subsequently release the NOx when a target temperature is reached.

1 . A device for reducing NOx emission in an engine exhaust stream of a Diesel engine system, comprising:
 an exhaust line comprising:
 a Diesel Oxidation Catalyst (DOC); 
 a Diesel Particulate Filter (DPF); and 
 a Selective Catalyst Reduction (SCR) system; and 
   a NOx absorber inside the Diesel Particulate Filter (DPF), said NOx absorber configured to store NOx at a low exhaust temperature and subsequently release said NOx when a target temperature is reached.   
     
     
         2 . A device according to  claim 1 , wherein said target temperature is correlated to an activation temperature of said Selective Catalyst Reduction (SCR) system. 
     
     
         3 . A device according to  claim 1 , wherein said NOx absorber is distributed in a plurality of inlet channels of said Diesel Particulate Filter (DPF). 
     
     
         4 . A device according to  claim 1 , wherein said NOx absorber in the Diesel Particulate Filter (DPF) comprises a washcoat element. 
     
     
         5 . A device according to  claim 1 , wherein said Selective Catalyst Reduction (SCR) system is an under floor SCR.