Apparatus for removing carbon particles from an exhaust gas stream of internal combustion engines

Abstract

An apparatus for removing carbon particles from exhaust gas of an internal combustion engine by oxidation of carbon particles with nitrogen dioxide is provided and comprises a module through which exhaust gas flows. The module is an open, self-regenerating module in which are disposed open-pored, metallic expanded material components, including at least two first noble-metal-coated components that increase nitrogen dioxide concentration in the exhaust gas for the oxidation of carbon particles. The first components are disposed by themselves in the module, or in an alternating arrangement with uncoated and/or coated second metallic expanded material components. The first components are configured such that nitric oxide that results thereon during the oxidation of the carbon particles again reacts to form nitrogen dioxide and is thus reused multiple times.

1 . An apparatus for removing carbon particles from exhaust gas of an internal combustion engine by oxidation of the carbon particles with nitrogen dioxide, comprising: 
 a module  1  through which said exhaust gas flows, wherein said module is an open, self-regenerating module in which are disposed open-pored, metallic expanded material components, including at least two first noble-metal-coated metallic expanded material components  2  that increase nitrogen dioxide concentration in said exhaust gas for said oxidation of said carbon particles, wherein said first noble-metal-coated, open-pored, metallic expanded material components  2  are disposed by themselves in said module  1 , or in an alternating arrangement with uncoated  3  and/or coated  4  second metallic expanded material components, and wherein said first noble-metal-coated metallic expanded material components  2  are configured such that nitric oxide that results thereon during said oxidation of said carbon particles again reacts to form nitrogen dioxide and is thus reusable multiple times.    
   
   
       2 . An apparatus according to  claim 1 , wherein said first and second metallic expanded material components  2 ,  3 ,  4  are comprised of an FeCr alloy for a high thermal resistance to oxidation, a high resistance to temperature changes, a high resistance to corrosion, and a high mechanical strength.  
   
   
       3 . An apparatus according to  claim 1 , wherein said first metallic expanded material component  2  is coated at least with a noble metal of the group Ru, Rh, Pd, Os, Ir, Pt, or a mixture of such noble metals.  
   
   
       4 . An apparatus according to  claim 2 , wherein said second coated metallic expanded material component  4  is coated with a compound that reduces the combustion temperature of carbon particles.  
   
   
       5 . An apparatus according to  claim 4 , wherein said second coated metallic expanded material component  4  is coated with a compound that reduces the combustion temperature of carbon particles, and wherein such compound is cerium orthovanadate (CeVO 4 ).  
   
   
       6 . An apparatus according to  claim 2 , wherein said first and second metallic expanded material components  2 ,  3 ,  4  are produced by a powder sintering process or a high quality casting process.  
   
   
       7 . An apparatus according to  claim 2 , wherein said metallic expanded material components  2 ,  3 ,  4  are embodied with a random cell geometry that causes a 3D flow through and has a mixing function.  
   
   
       8 . An apparatus according to  claim 2 , wherein said metallic expanded material components  2 ,  3 ,  4  are embodied with a relative density in a range of from 2 to 20%.  
   
   
       9 . An apparatus according to  claim 2 , wherein said metallic expanded material components  2 ,  3 ,  4  are embodied with a pore count in a range of from 3 to 80 ppi.  
   
   
       10 . An apparatus according to  claim 2 , wherein said metallic expanded material components  2 ,  3 ,  4  have a freely selectable geometry.  
   
   
       11 . An apparatus according to  claim 2 , wherein said metallic expanded material components  2 ,  3 ,  4  are electrically conductive.  
   
   
       12 . An apparatus according to  claim 3 , wherein said first metallic expanded material component  2  is coated directly, or by impregnation of a wash-coat, with a noble metal from the group Ru, Rh, Pd, Os, Ir, Pt, or a mixture of these noble metals, in a concentration of 0.1 g-5.0 g per liter metallic expanded material.  
   
   
       13 . An apparatus according to  claim 5 , wherein said cerium orthovanadate is applied to said second coated metallic expanded material component  4  via a plasma process, a wash-coat process, or a sol gel process, in a concentration of 0.1 g-25 g cerium orthovanadate per liter of metallic expanded material.  
   
   
       14 . An apparatus according  claim 2 , wherein a pore count of said metallic expanded material component  2 ,  3 ,  4  varies in a direction of said exhaust gas flow.  
   
   
       15 . An apparatus according to  claim 14 , wherein said pore count increases in the direction of said exhaust gas flow.  
   
   
       16 . An apparatus according to  claim 2 , wherein a spacing of 0-50 mm exists between individual ones or all of said metallic expanded material components  2 ,  3 ,  4 .  
   
   
       17 . An apparatus according to  claim 2 , wherein said module  1  is a metallic module, and wherein said metallic expanded material components  2 ,  3 ,  4  are introduced in a positive manner, via a soldering process, into said metallic module.  
   
   
       18 . An apparatus according to  claim 2 , wherein said module  1  is a metallic module, and wherein said metallic expanded material components  2 ,  3 ,  4  are embedded into said metallic module via a bearing mat.  
   
   
       19 . An apparatus according to  claim 1 , wherein said module  5  is comprised of a plurality of identical modules  1 ′ or a plurality of differently embodied modules.  
   
   
       20 . An apparatus according to  claim 19 , wherein said plurality of modules are disposed in said module  5  parallel to said exhaust gas flow.