Method for desulfurizing gasoline or diesel fuel for use in an internal combustion engine

Abstract

A fuel processing method is operable to remove substantially all of the sulfur present in an undiluted oxygenated hydrocarbon fuel stock supply which contains an oxygenate and which is used to power an internal combustion engine in a mobile environment, such as an automobile, bus, truck, boat, or the like, or in a stationary environment. The fuel stock can be gasoline, diesel fuel, or other like fuels which contain relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, and the like. The undiluted hydrocarbon fuel supply is passed through a nickel reactant desulfurizer bed wherein essentially all of the sulfur in the organic sulfur compounds reacts with the nickel reactant, and is converted to nickel sulfide, while the desulfurized organic remnants continue through the remainder of the fuel processing system. The method can be used to desulfurize either a liquid or a gaseous fuel stream, which contains an oxygenate such as MTBE, ethanol, methanol, or the like. The inclusion of the oxygenate serves to extend the useful life of the desulfurization apparatus and method.

What is claimed is:  
     
         1 . A method for desulfurizing a hydrocarbon fuel stream so as to convert the hydrocarbon fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) introducing a hydrocarbon fuel stream which contains an oxygenate into said nickel reactant desulfurization station; and    c) said oxygenate being present in said fuel stream in an amount which is effective to provide an effluent fuel stream at an exit end of said nickel reactant station which effluent fuel stream contains no more than about 0.05 ppm sulfur.    
     
     
         2 . The method of  claim 1  wherein the oxygenate is selected from the group consisting of water, alcohol, ether, and mixtures thereof.  
     
     
         3 . The method of  claim 2  wherein the oxygenate is selected from the group consisting of water, MTBE, ethanol, methanol, and mixtures thereof.  
     
     
         4 . The method of  claim 1  wherein said hydrocarbon fuel is gasoline.  
     
     
         5 . The method of  claim 1  wherein said hydrocarbon fuel is diesel fuel.  
     
     
         6 . A method for desulfurizing a gasoline or diesel fuel stream so as to convert the gasoline fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) introducing a gasoline or diesel fuel stream which contains an oxygenate into said nickel reactant desulfurization station; and    c) said oxygenate being present in said fuel stream in an amount which is effective to provide an effluent fuel stream at an exit end of said nickel reactant station which effluent fuel stream contains no more than about 0.05 ppm sulfur.    
     
     
         7 . The method of  claim 5  wherein the oxygenate is selected from the group consisting or water, alcohol, ether, and mixtures thereof.  
     
     
         8 . The method of  claim 7  wherein the oxygenate is selected from the group consisting of water, MTBE, ethanol, methanol, and mixtures thereof.  
     
     
         9 . A method for desulfurizing a gasoline or diesel fuel stream so as to convert the fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) introducing a gasoline or diesel fuel stream which contains an oxygenate into said nickel reactant desulfurization station; and    c) said oxygenate being present in said fuel stream in an amount which is effective to provide a continuous fuel stream at an exit end of said nickel reactant station which continuous fuel stream contains on average no more than about 0.05 ppm sulfur.    
     
     
         10 . A method for desulfurizing a gasoline or diesel fuel stream so as to convert the fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) introducing a gasoline or diesel fuel stream which contains an oxygenate into said nickel reactant desulfurization station; and    c) said oxygenate being converted to isobutylene and methanol by said nickel catalyst in amounts which are effective to inhibit carbon deposition in said nickel catalyst station and provide a continuous fuel stream at an exit end of said nickel reactant station which continuous fuel stream contains no more than about 0.05 ppm sulfur.    
     
     
         11 . A method for desulfurizing a gasoline or diesel fuel stream so as to convert the fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) introducing a gasoline or diesel fuel stream which contains an oxygenate into said nickel reactant desulfurization station, said oxygenate being present in said fuel stream in an amount which is effective to provide a low sulfur content fuel stream at an exit end of said nickel catalyst station which low sulfur content fuel stream contains no more than about 0.05 ppm sulfur; and    c) said oxygenate being converted to isobutylene and methanol by said nickel reactant during said desulfurizing step, said low sulfur content fuel stream being formed so long as said nickel reactant continues to convert the oxygenate.    
     
     
         12 . A method for desulfurizing a liquid gasoline or diesel fuel stream so as to convert the fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert All sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) maintaining said nickel reactant desulfurization station at a temperature in the range of about 300° F. to about 450° F.;    c) introducing a liquid gasoline or diesel fuel stream which contains an oxygenate into said nickel reactant desulfurization station, said oxygenate being present in said fuel stream in an amount which is effective to provide a low sulfur content fuel stream at an exit end of said nickel reactant station which low sulfur content fuel stream contains no more than about 0.05 ppm sulfur; and    d) said oxygenate being converted to isobutylene and methanol by said nickel reactant during said desulfurizing step, said low sulfur content fuel stream being formed so long as said nickel reactant continues to convert the oxygenate.    
     
     
         13 . A method for desulfurizing a liquid gasoline or diesel fuel stream so as to convert the fuel stream into a low sulfur content fuel, which low sulfur content fuel is suitable for use in an internal combustion engine, said method comprising the steps of: 
 a) providing a nickel reactant desulfurization station which is operative to convert sulfur contained in organic sulfur compounds contained in the fuel stream to nickel sulfide;    b) maintaining said nickel reactant desulfurization station at a temperature in the range of about 300° F. to about 450° F.;    c) introducing a mixture of about 2% to about 5% water and a liquid gasoline or diesel fuel stream, which mixture contains an oxygenate, into said nickel reactant desulfurization station, said oxygenate being present in said mixture in an amount which is effective to provide a low sulfur content fuel stream at an exit end of said nickel reactant station, which low sulfur content fuel stream contains no more than about 0.05 ppm sulfur; and    d) said oxygenate being consumed by said nickel reactant during said desulfurizing step, said low sulfur content fuel stream being formed so long as said nickel reactant continues to consume the oxygenate.    
     
     
         14 . The method of  claim 13  wherein the water in said mixture is the sole oxygenate in said mixture.  
     
     
         15 . The method of  claim 13  wherein the oxygenate includes an alcohol present in said fuel stream.  
     
     
         16 . The method of  claim 15  wherein the alcohol is selected from the group consisting of methanol, ethanol, propanol, and mixtures thereof.  
     
     
         17 . The method of  claim 13  wherein said oxygenate is an ether.  
     
     
         18 . The method of  claim 17  wherein said oxygenate is MTBE.