Low NOx burner

Abstract

A process for operating a combustion burner employing a combustion mixture of a carbonaceous fuel, hydrogen and a molecular oxygen-containing gas and at least one solid combustion catalyst is disclosed.

Having described the invention, what is claimed is:  
     
         1 . A process for operating a combustion burner comprising: combusting a carbonaceous fuel and hydrogen in the presence of at least one solid combustion catalyst by bringing a combustion mixture of the carbonaceous fuel, hydrogen and a molecular oxygen-containing gas into contact with at least one aforesaid solid catalyst at a space velocity in the range of from about 1000 to about 2×10 6  volumes of combustion mixture per hour per volume of catalyst, at a sufficient ratio of molecular oxygen-to-each carbon atom of the carbonaceous fuel to ensure complete combustion of the carbonaceous fuel to carbon dioxide and water and at a sufficient ratio of hydrogen to each carbon atom of the carbonaceous fuel such that the reaction between hydrogen and oxygen generates sufficient exothermic heat to ignite the carbonaceous fuel and with a stoichiometry in the range of from about 0.45 to about 0.95 such that the carbonaceous fuel is combusted at a temperature which minimizes the presence of NO x  in the stream of combustion products produced by the burner.  
     
     
         2 . The process of  claim 1  wherein the oxygen-containing gas is air.  
     
     
         3 . The process of  claim 1  wherein the carbonaceous fuel is methane or natural gas.  
     
     
         4 . The process of  claim 1  wherein the space velocity is in the range of from about 1000 to about 5×10 6  volumes of combustion mixture per hour per volume of catalyst.  
     
     
         5 . The process of  claim 4  wherein the space velocity is in the range of from about 5000 to about 3×10 6  volumes of combustion mixture per hour per volume of catalyst.  
     
     
         6 . The process of  claim 1  wherein the mole ratio of molecular oxygen-to each carbon atom of the carbonaceous fuel is in the range of from about 2:1 to about 100:1.  
     
     
         7 . The process of  claim 6  wherein the mole ratio of molecular oxygen-to each carbon atom of the carbonaceous fuel is in the range of from about 2:1 to about 50:1.  
     
     
         8 . The process of  claim 1  wherein the mole ratio of hydrogen to each carbon atom of the carbonaceous fuel is in the range of from about 0.01:1 to about 2:1.  
     
     
         9 . The process of  claim 8  wherein the mole ratio of hydrogen to each carbon atom of the carbonaceous fuel is in the range of from about 0.03:1 to about 1:1.  
     
     
         10 . The process of  claim 1  wherein the stoichiometry is in the range of from about 0.60 to about 0.95.  
     
     
         11 . The process of  claim 1  wherein the at least one combustion catalyst comprises a noble metal.  
     
     
         12 . The process of  claim 11  wherein the at least one combustion catalyst comprises a platinum- or palladium-containing component or both.  
     
     
         13 . The process of  claim 1  wherein a single combustion catalyst is employed.  
     
     
         14 . The process of  claim 1  wherein two combustion catalysts are employed.  
     
     
         15 . A process for the production of a mono-olefin from a paraffinic hydrocarbon having at least two carbon atoms in a gas stream passing through a reactor heated by combustion products from a combustion burner in which a carbonaceous fuel and hydrogen are combusted in the presence of at least one solid combustion catalyst by bringing a combustion mixture of the carbonaceous fuel, hydrogen and a molecular oxygen-containing gas into contact with at least one aforesaid solid catalyst at a space velocity in the range of from about 1000 to about 2×10 6  volumes of combustion mixture per hour volume of catalyst at a sufficient ratio of the molecular oxygen-to-each carbon atom of the carbonaceous fuel for complete combustion of the carbonaceous fuel to carbon dioxide and water and at a sufficient ratio of hydrogen to each carbon atom of the carbonaceous fuel such that the reaction between hydrogen and oxygen generates sufficient exothermic heat to ignite the carbonaceous fuel and with a stoichiometry in the range of from about 0.45 to about 0.95, such that the carbonaceous fuel is combusted at a temperature which minimizes the presence of NO x  in the stream of combustion products produced by the burner.  
     
     
         16 . The process of  claim 15  wherein the oxygen-containing gas is air.  
     
     
         17 . The process of  claim 15  wherein the carbonaceous fuel is methane or natural gas.  
     
     
         18 . The process of  claim 15  wherein the space velocity is in the range of from about 1000 to about 5×10 6  volumes of combustion mixture per hour per volume of catalyst.  
     
     
         19 . The process of  claim 15  wherein the mole ratio of molecular oxygen-to-each carbon of the carbonaceous fuel is in the range of from about 2:1 to about 100:1.  
     
     
         20 . The process of  claim 23  where in the mole ratio of hydrogen-to-each carbon of the carbonaceous fuel is in the range of from about 0.01:1 to about 2:1.  
     
     
         21 . The process of  claim 15  wherein the stoichiometry is in the range of from about 0.60 to about 0.95.  
     
     
         22 . The process of  claim 15  wherein the at least one combustion catalyst comprises a nobel metal.  
     
     
         23 . The process of  claim 22  wherein the at least one combustion catalyst comprises a platinum- or palladium-containing component or both.  
     
     
         24 . The process of  claim 15  wherein a single combustion catalyst is employed.  
     
     
         25 . The process of  claim 15  wherein two combustion catalysts are employed.