Patent ID: 7984609

Claim:
An exhaust gas post treatment system for nitrogen oxide and particle reduction of an internal combustion operated with excess air, comprising: an oxidation catalytic converter disposed in the exhaust gas stream of the internal combustion engine for converting at least a portion of the nitric oxide contained in the exhaust gas stream into nitrogen dioxide; a first particle separator or particle filter disposed in said exhaust gas stream downstream of said oxidation catalytic converter, wherein said first particle separator or particle filter is adapted to convert carbon particles accumulated in said first particle separator or particle filter into carbon monoxide, carbon dioxide, nitrogen and nitric oxide with the aid of nitrogen dioxide contained in said exhaust gas stream, and wherein said oxidation catalytic converter and said first particle separator or particle filter form a single component such that said first particle separator or particle filter is at least partially coated or impregnated with an active component that forms said oxidation catalytic converter; wherein a partial exhaust gas stream is branched off from said exhaust gas stream upstream of said first particle separator or particle filter; a supply tank for a reduction agent; a metering device for receiving a reduction agent from the supply tank and for adding the reduction agent to said partial exhaust gas stream at a supply location, wherein the reduction agent is ammonia or a material that is adapted to release ammonia downstream of the supply location as a result of the hot exhaust gas; a second particle separator or particle filter disposed in said partial exhaust gas stream downstream of the supply location for the reduction agent; wherein downstream of said second particle separator or particle filter and downstream of said first particle separator or particle filter said partial exhaust gas stream is returned to said exhaust gas stream at a return location; and an SCR catalytic converter disposed downstream of said return location for reducing nitrogen oxides contained in said exhaust gas stream to nitrogen and water vapor with the aid of ammonia or released ammonia by way of selective catalytic reduction.