Process for the catalytic selective oxidation of sulfur compounds

Abstract

A process for the catalytic selective oxidation of sulfur compounds in a hydrocarbonaceous feedstock to sulfur dioxide is provided. A gaseous feed mixture of the hydrocarbonaceous feedstock and a molecular-oxygen containing gas is contacted with a catalyst at a temperature of at most 500 ° C., wherein the oxygen-to-carbon ratio of the feed mixture is below 0.15. The catalyst contains a group VIII noble metal on a catalyst carrier. The formed sulfur dioxide can be removed from the hydrocarbonaceous feedstock.

We claim:  
     
         1 . A process for the catalytic selective oxidation of sulfur compounds in a hydrocarbonaceous feedstock to sulfur dioxide, comprising the steps of: contacting a gaseous feed mixture of the hydrocarbonaceous feedstock and a molecular-oxygen containing gas with a catalyst at a temperature of at most 500° C., said catalyst comprising a group VIII noble metal on a catalyst carrier, said feed mixture having oxygen-to-carbon ratio of below 0.15.  
     
     
         2 . The process of  claim 1  wherein the oxygen-to-carbon ratio of the feed mixture is below 0.10.  
     
     
         3 . The process of  claim 1  wherein the catalyst carrier is a refractory oxide.  
     
     
         4 . The process of  claim 3  wherein the refractory oxide comprises partially stabilised or stabilised zirconia.  
     
     
         5 . The process of  claim 1  wherein the group VIII noble metal is Pt, Rh or Ir or a combination of two or more thereof.  
     
     
         6 . The process of  claim 5  wherein the oxygen-to-carbon ratio of the feed mixture is below 0.10.  
     
     
         7 . The process of  claim 5  wherein the catalyst carrier is a refractory oxide.  
     
     
         8 . The process of  claim 7  wherein the refractory oxide comprises partially stabilised or stabilised zirconia.  
     
     
         9 . The process of  claim 1  wherein the temperature is maintained in the range of from 200 to 500° C.  
     
     
         10 . The process of  claim 1  wherein the temperature is maintained in the range of from 200 to 300° C.  
     
     
         11 . The process of  claim 1  wherein the feed mixture is contacted with the catalyst at a pressure in the range of from 1 to 10 bar (absolute).  
     
     
         12 . The process of  claim 11  wherein the feed mixture is contacted with the catalyst at a pressure in the range of from of from 1 to 5 bar (absolute).  
     
     
         13 . The process of  claim 1  wherein the feed mixture is contacted with the catalyst at ambient pressure.  
     
     
         14 . The process of  claim 1  wherein the hydrocarbonaceous feedstock is a gaseous hydrocarbonaceous feedstock.  
     
     
         15 . The process of  claim 14  wherein the hydrocarbonaceous feedstock is methane or natural gas.  
     
     
         16 . The process of  claim 14  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 10% v/v.  
     
     
         17 . The process of  claim 16  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 5% v/v.  
     
     
         18 . The process of  claim 15  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 10% v/v.  
     
     
         19 . The process of  claim 18  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 5% v/v.  
     
     
         20 . The process of  claim 1  wherein the feedstock is a liquid hydrocarbonaceous feedstock containing at most 1000 ppmw sulfur.  
     
     
         21 . A process for the catalytic selective oxidation of sulfur compounds in a methane or natural gas feedstock to sulfur dioxide, comprising the steps of: contacting a gaseous feed mixture of the methane or natural gas feedstock and a molecular-oxygen containing gas with a catalyst at a temperature of at most 500° C., said catalyst comprising a group VIII noble metal on a refractory oxide, said feed mixture having oxygen-to-carbon ratio of below 0.15.  
     
     
         22 . The process of  claim 21  wherein the group VIII noble metal is Pt, Rh or Ir or a combination of two or more thereof.  
     
     
         23 . The process of  claim 21  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 10% v/v.  
     
     
         24 . The process of  claim 23  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 5% v/v.  
     
     
         25 . A process for the desulfurization of a hydrocarbonacous feedstock comprising the steps of: contacting a gaseous feed mixture of the hydrocarbonaceous feedstock and a molecular-oxygen containing gas with a catalyst at a temperature of at most 500° C., said catalyst comprising a group VIII noble metal on a catalyst carrier, said feed mixture having oxygen-to-carbon ratio of below 0.15, thereby selectively oxidizing sulfur compounds in the hydrocarbonaceous feedstock to sulfur dioxide; and removing the thus-formed sulfur dioxide from the hydrocarbonaceous feedstock.  
     
     
         26 . The process of  claim 25  wherein the oxygen-to-carbon ratio of the feed mixture is below 0.10.  
     
     
         27 . The process of  claim 25  wherein the catalyst carrier is a refractory oxide.  
     
     
         28 . The process of  claim 27  wherein the refractory oxide comprises partially stabilised or stabilised zirconia.  
     
     
         29 . The process of  claim 25  wherein the group VIII noble metal is Pt, Rh or Ir or a combination of two or more thereof.  
     
     
         30 . The process of  claim 29  wherein the oxygen-to-carbon ratio of the feed mixture is below 0.10.  
     
     
         31 . The process of  claim 29  wherein the catalyst carrier is a refractory oxide.  
     
     
         32 . The process of  claim 31  wherein the refractory oxide comprises partially stabilised or stabilised zirconia.  
     
     
         33 . The process of  claim 25  wherein the temperature is maintained in the range of from 200 to 500° C.  
     
     
         34 . The process of  claim 25  wherein the temperature is maintained in the range of from 200 to 300° C.  
     
     
         35 . The process of  claim 25  wherein the feed mixture is contacted with the catalyst at a pressure in the range of from 1 to 10 bar (absolute).  
     
     
         36 . The process of  claim 35  wherein the feed mixture is contacted with the catalyst at a pressure in the range of from of from 1 to 5 bar (absolute).  
     
     
         37 . The process of  claim 25  wherein the feed mixture is contacted with the catalyst at ambient pressure.  
     
     
         38 . The process of  claim 25  wherein the hydrocarbonaceous feedstock is a gaseous hydrocarbonaceous feedstock.  
     
     
         39 . The process of  claim 38  wherein the hydrocarbonaceous feedstock is methane or natural gas.  
     
     
         40 . The process of  claim 38  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 10% v/v.  
     
     
         41 . The process of  claim 40  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 5% v/v.  
     
     
         42 . The process of  claim 39  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 10% v/v.  
     
     
         43 . The process of  claim 42  wherein the hydrocarbonaceous feedstock comprises hydrogen sulfide in a concentration of at most 5% v/v.  
     
     
         44 . The process of  claim 25  wherein the feedstock is a liquid hydrocarbonaceous feedstock containing at most 1000 ppmw sulfur.