Device and method for purification of exhaust gases from an internal combustion engine

Abstract

The invention relates to device for emission control of an internal combustion engine ( 10 ) including an exhaust tract ( 12 ) comprising a NO x catalyst ( 14 ), and a reductant feeder ( 16 ) designed to deliver reductant to the exhaust tract ( 12 ) upstream of the NO x catalyst ( 14 ). In accordance with the invention, the reductant feeder ( 16 ) comprises a reformer ( 18 ) designed to react gas exhausted by the engine ( 10 ) and fuel into a reformate serving as reductant. In addition, the invention relates to a method for emission control of an internal combustion engine ( 10 ) wherein a NO x catalyst ( 14 ) provided in the exhaust tract ( 12 ) is supplied with reductant. In this arrangement use is made of reformate generated by a reformer ( 18 ) as the reductant, the reformer ( 18 ) generating the reformate from the engine ( 10 ) exhaust gas and fuel.

1 - 16 . (canceled) 
   
   
       17 . A device for emission control of an internal combustion engine including an exhaust tract comprising a NO x  catalyst, and a reductant feeder configured to deliver reductant to the exhaust tract upstream of the NO x  catalyst, wherein the reductant feeder comprises a reformer configured to react gas exhausted by the engine and fuel into a reformate serving as reductant. 
   
   
       18 . The device as set forth in claim  1 , wherein the exhaust gas supplied to the reformer is obtained via a exhaust tract branch-off disposed directly downstream of the engine. 
   
   
       19 . The device as set forth in claim  1 , wherein the exhaust gas supplied to the reformer is obtained via a exhaust tract branch-off comprising an exhaust gas metering device. 
   
   
       20 . The device as set forth in  claim 19 , wherein the exhaust gas metering device comprises a valving apparatus. 
   
   
       21 . The device as set forth in  claim 19 , wherein the exhaust gas metering device comprises a blower. 
   
   
       22 . The device as set forth in  claim 17 , wherein the exhaust gas supplied to the reformer is obtained via a exhaust tract branch-off disposed upstream of a further catalyst disposed upstream of the NO x  catalyst. 
   
   
       23 . The device as set forth in  claim 17 , further comprising a fuel pump, designed to pump fuel from a fuel tank. 
   
   
       24 . The device as set forth in  claim 17 , wherein the fuel is obtained from a fuel line of the fuel system of the engine and that the fuel is supplied to the reformer via a fuel valving apparatus. 
   
   
       25 . A method for emission control of an internal combustion engine wherein a NO x  catalyst provided in the exhaust tract is supplied with reductant, comprising:
 generating reformate from the engine exhaust gas and fuel using a reformer; and   using the reformate generated by the reformer as reductant.   
   
   
       26 . The method as set forth in  claim 25 , wherein the exhaust gas supplied to the reformer is obtained via an exhaust tract branch-off disposed directly downstream of the engine. 
   
   
       27 . The method as set forth in  claim 26 , wherein the exhaust gas supplied to the reformer is obtained via an exhaust tract branch-off containing an exhaust gas metering device. 
   
   
       28 . The method as set forth in  claim 27 , wherein the exhaust gas metering device comprises a valving apparatus. 
   
   
       29 . The method as set forth in  claim 27 , wherein the exhaust gas metering device comprises a blower. 
   
   
       30 . The method as set forth in  claim 25 , wherein the exhaust gas supplied to the reformer is obtained via a exhaust tract branch-off disposed upstream of a further catalyst disposed upstream of the NO x  catalyst. 
   
   
       31 . The method as set forth in  claim 25 , wherein the fuel supplied to the reformer is delivered by a fuel pump. 
   
   
       32 . The method as set forth in  claim 25 , wherein the fuel is obtained from a fuel line of the fuel system of the engine and that the fuel is supplied to the reformer via a fuel valving apparatus.