Emission control system and a method for operating an emission control system

Abstract

In an emission control system that includes a particle filter, an arrangement is provided upstream of the particle filter, the arrangement being configured to prevent the development of ash-forming compounds of sulfur in the exhaust. The emission control system may be used with a diesel engine.

What is claimed is:  
     
         1 . An emission control system, comprising: 
 a particle filter; and    an arrangement disposed upstream from the particle filter, the arrangement being configured to prevent development of ash-forming compounds of sulfur contained in an exhaust gas.    
     
     
         2 . The emission control system according to  claim 1 , wherein the emission control system is configured for use with an internal combustion engine.  
     
     
         3 . The emission control system according to  claim 1 , wherein the arrangement includes a SO x  collector.  
     
     
         4 . The emission control system according to  claim 1 , wherein the arrangement includes a NO x  collector.  
     
     
         5 . The emission control system according to  claim 3 , wherein the arrangement includes a NO x  collector.  
     
     
         6 . The emission control system according to  claim 1 , wherein the arrangement includes an oxidation catalyst.  
     
     
         7 . The emission control system according to  claim 3 , wherein the arrangement includes an oxidation catalyst.  
     
     
         8 . The emission control system according to  claim 5 , wherein the arrangement includes an oxidation catalyst.  
     
     
         9 . A method for operating an emission control system, the emission control system including a particle filter and an arrangement disposed upstream from the particle filter, the arrangement being configured to prevent development of ash-forming compounds of sulfur contained in an exhaust gas, the method comprising the step of: 
 preventing development of ash-forming compounds of sulfur contained in the exhaust gas.    
     
     
         10 . The method according to  claim 9 , further comprising the steps of: 
 operating the emission control system in a normal operating phase with a lean exhaust composition to store sulfur contained in the exhaust gas; and    operating the emission control system in a regeneration phase with a rich exhaust composition to release stored sulfur as at least one gaseous compound.    
     
     
         11 . The method according to  claim 10 , wherein the step of operating the emission control system in the regeneration phase includes the substep of raising an exhaust temperature to between 550° C. and 700° C.  
     
     
         12 . A method for reducing ash components in a particle filter of an exhaust system for a diesel engine, comprising the steps of: 
 maintaining ash-forming exhaust components in a gaseous state in a catalyst disposed upstream from the particle filter;    storing sulfur in the catalyst; and    passing the ash-forming exhaust components in the gaseous state through the particle filter.    
     
     
         13 . A device for reducing ash components in a particle filter of an exhaust system of a diesel engine, comprising: 
 a catalyst disposed upstream from the particle filter, the catalyst including a sulfur-storing catalyst configured as a NO x  collector, the catalyst being further configured to change ash-forming exhaust components to a gaseous state flowable through the particle filter.