Apparatus for removing mixed nitrogen oxides, carbon monoxide, hydrocarbons and diesel particulate matter from diesel engine exhaust streams at temperatures at or below 280 degrees c

Abstract

Disclosed is a catalytic unit that removes contaminates and particulates, including nitrogen oxides and soot, from diesel engine emissions without the use of chemical agents. The disclosed apparatus comprises a flow through device in fluid communication with a reduction unit, which is in fluid communication with a diesel particulate filter. The flow through device is coated with hematite and bixbyite in a ratio ranging from 1:1 to 9:1. The reduction unit is a catalytic substrate comprising one or more transition metals supported on a molecular sieve coated with an oxide catalyst. The diesel particulate filter has an oxide coating and a noble metal coating. The flow through device converts nitric oxide into nitrogen dioxide. The reduction unit converts most of the nitrogen dioxide into nitrogen, water, carbon monoxide and carbon dioxide. The diesel particulate filter traps remaining soot and coverts it and the carbon monoxide into carbon dioxide.

1 . An apparatus for removing contaminants and particulates, including nitrogen oxides and soot, from diesel engine emissions, comprising: a flow through device coated with a first catalyst comprising hematite (Fe 2 O 3 ) and bixbyite ((Mm 1.5 ,Fe 0.5 )O 3 ) wherein the ratio of hematite to bixbyite ranges from 1:1 to 9:1; wherein said flow through device is in fluid communication with an reduction unit comprising a catalytic substrate coated with a second catalyst, said substrate comprising one or more transition metals supported on a molecular sieve and said second catalyst comprising one or more stabilizing oxides coating the molecular sieve; wherein said reduction unit is in fluid communication with a diesel particulate filter coated with a first coating comprising tin oxide, aluminum oxide and zirconium oxide and a second coating comprising gold, silver, palladium or platinum. 
     
     
         2 . An apparatus according to  claim 1  wherein the second coating comprises platinum. 
     
     
         3 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite. 
     
     
         4 . An apparatus according to  claim 2  wherein in the molecular sieve is zeolite and the transition metal includes one or more of Cu, Co, Fe, Ag and Mo. 
     
     
         5 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite and the transition metal is Cu. 
     
     
         6 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite and the transition metal is Fe. 
     
     
         7 . An apparatus according to  claim 2  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo. 
     
     
         8 . An apparatus according to  claim 2  wherein the transition metal is Cu. 
     
     
         9 . An apparatus according to  claim 2  wherein the transition metal is Fe. 
     
     
         10 . An apparatus according to  claim 2  wherein the stabilizing oxide is cerium oxide. 
     
     
         11 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite and the stabilizing oxide is cerium oxide. 
     
     
         12 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite, the transition metal includes on or more of Cu, Co, Fe, Ag and Mo, and the stabilizing oxide is cerium oxide. 
     
     
         13 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite, the transition metal is Cu, and the stabilizing oxide is cerium oxide. 
     
     
         14 . An apparatus according to  claim 2  wherein the molecular sieve is zeolite, the transition metal is Fe and the stabilizing oxide is cerium oxide. 
     
     
         15 . An apparatus according to  claim 1  wherein the molecular sieve is zeolite. 
     
     
         16 . An apparatus according to  claim 15  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo. 
     
     
         17 . An apparatus according to  claim 15  wherein the transition metal is Cu. 
     
     
         18 . An apparatus according to  claim 15  wherein the transition metal is Fe. 
     
     
         19 . An apparatus according to  claim 15  wherein the stabilizing oxide is cerium oxide. 
     
     
         20 . An apparatus according to  claim 15  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo and the stabilizing oxide is cerium oxide. 
     
     
         21 . An apparatus according to  claim 15  wherein the transition metal is Cu and the stabilizing oxide is cerium oxide. 
     
     
         22 . An apparatus according to  claim 15  wherein the transition metal is Fe and the stabilizing oxide is cerium oxide. 
     
     
         23 . An apparatus according to  claim 1  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo. 
     
     
         24 . An apparatus according to  claim 23  wherein the stabilizing oxide is cerium oxide. 
     
     
         25 . An apparatus according to  claim 1  wherein the transition metal is Cu. 
     
     
         26 . An apparatus according to  claim 1  wherein the transition metal is Fe. 
     
     
         27 . An apparatus according to  claim 1  wherein the transition metal is Cu and the stabilizing oxide is cerium oxide. 
     
     
         28 . An apparatus according to  claim 1  wherein the transition metal is Fe and the stabilizing oxide is cerium oxide. 
     
     
         29 . An apparatus according to  claim 1  wherein the stabilizing oxide is cerium oxide. 
     
     
         30 . An apparatus for removing contaminants and particulates, including nitrogen oxides and soot, from diesel engine emissions, comprising: a flow through device coated with a first catalyst comprising hematite (Fe 2 O 3 ) and bixbyite ((Mn 1.5 ,Fe 0.5 )O 3 ), wherein the ratio of hematite to bixbyite ranges from 1:1 to 9:1; wherein said flow through device is in fluid communication with a reduction unit comprising a catalytic substrate coated with a second catalyst, said substrate comprising one or more transition metals supported on a molecular sieve and said second catalyst comprising one or more stabilizing oxides coating the molecular sieve. 
     
     
         31 . An apparatus according to  claim 30  wherein the molecular sieve is zeolite. 
     
     
         32 . An apparatus according to  claim 31  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo. 
     
     
         33 . An apparatus according to  claim 31  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo and the stabilizing oxide is cerium oxide. 
     
     
         34 . An apparatus according to  claim 31  wherein the transition metal is Cu and the stabilizing oxide is cerium oxide. 
     
     
         35 . An apparatus according to  claim 31  wherein the transition metal is Fe and the stabilizing oxide is cerium oxide. 
     
     
         36 . An apparatus according to  claim 31  wherein the stabilizing oxide is cerium oxide. 
     
     
         37 . An apparatus according to  claim 31  wherein the transition metal is Cu. 
     
     
         38 . An apparatus according to  claim 31  wherein the transition metal is Fe. 
     
     
         39 . An apparatus according to  claim 30  wherein the transition metal includes one or more of Cu, Co, Fe, Ag and Mo. 
     
     
         40 . An apparatus according to  claim 39  wherein the stabilizing oxide is cerium oxide. 
     
     
         41 . An apparatus according to  claim 30  wherein the transition metal is Cu. 
     
     
         42 . An apparatus according to  claim 30  wherein the transition metal is Fe. 
     
     
         43 . An apparatus according to  claim 41  wherein the stabilizing oxide is cerium oxide. 
     
     
         44 . An apparatus according to  claim 42  wherein the stabilizing oxide is cerium oxide. 
     
     
         45 . An apparatus according to  claim 30  wherein the stabilizing oxide is cerium oxide.