Processes for removing hydrogen sulfide from refined hydrocarbon streams

Abstract

A method for reducing the amount of hydrogen sulfide present in refined hydrocarbon streams and reducing the amount of corrosion in processing equipment contacting the refined hydrocarbon stream. The method includes adding a corrosion inhibitor to the refined hydrocarbon stream in contact with the processing equipment to protect the processing equipment and adding glyoxal to the refined hydrocarbon stream in contact with the protected processing equipment. The corrosion inhibitor includes an organic soluble compound having a nitrogen-containing ring.

1 . A method for reducing the amount of hydrogen sulfide present in a refined hydrocarbon stream and reducing the amount of corrosion in processing equipment contacting the refined hydrocarbon stream, said method comprising adding a corrosion inhibitor to the refined hydrocarbon stream in contact with the processing equipment to protect the processing equipment and adding glyoxal to the refined hydrocarbon stream in contact with the protected processing equipment, wherein said corrosion inhibitor comprises an organic soluble compound having a nitrogen-containing ring. 
     
     
         2 . The method of  claim 1  wherein the refined hydrocarbon stream is selected from the group consisting of gas oil, naphtha, FCC slurry, diesel fuel, fuel oil, jet fuel, gasoline, kerosene and vacuum residua. 
     
     
         3 . The method of  claim 1  wherein the refined hydrocarbon stream is at an elevated temperature. 
     
     
         4 . The method of  claim 3  wherein the refined hydrocarbon stream is at a temperature of from about ambient to about 150° C. 
     
     
         5 . The method of  claim 1  wherein the processing equipment is a pipeline or a holding tank. 
     
     
         6 . The method of  claim 5 , wherein the processing equipment is made of carbon steel. 
     
     
         7 . The method of  claim 1 , wherein the corrosion inhibitor comprises a five-membered or six-membered nitrogen-containing ring. 
     
     
         8 . The method of  claim 7 , wherein corrosion inhibitor is an imidazoline derivative. 
     
     
         9 . The method of  claim 8 , wherein the corrosion inhibitor is a fatty acid imidazoline. 
     
     
         10 . The method of  claim 8 , wherein the fatty acid imidazoline has the following structure: 
       
         
           
           
               
               
           
         
         wherein R and R′ are each, separately, a C 6  to C 36  alkyl, alkylene or aromatic group. 
       
     
     
         11 . The method of  claim 7 , wherein the nitrogen-containing ring is a pyrimidine derivative. 
     
     
         12 . The method of  claim 11  wherein the pyrimidine derivative is a fatty acid pyrimidine. 
     
     
         13 . The method of  claim 12  wherein the fatty acid pyrimidine has the following structure: 
       
         
           
           
               
               
           
         
         wherein R a  and R b  are each, separately, a C 6  to C 36  alkyl, alkylene or aromatic group. 
       
     
     
         14 . The method of  claim 1  wherein the corrosion inhibitor is injected into the refined hydrocarbon stream. 
     
     
         15 . The method of  claim 1  wherein the corrosion inhibitor is present from about 2 ppm by volume to about 100 ppm by volume, based on the volume of the refined hydrocarbon stream. 
     
     
         16 . The method of  claim 1 , wherein the corrosion inhibitor provides a protective coating onto the processing equipment after at least about 5 minutes of adding the corrosion inhibitor to the refined hydrocarbon stream in contact with the processing equipment. 
     
     
         17 . The method of  claim 1 , wherein glyoxal is added to the refined hydrocarbon stream in an amount of from about 1 ppm to about 3000 ppm by volume, based on the volume of the refined hydrocarbon stream. 
     
     
         18 . The method of  claim 1 , wherein the corrosion inhibitor continues to be added to the refined hydrocarbon stream after the glyoxal has been added. 
     
     
         19 . The method of  claim 18 , wherein the corrosion inhibitor continues to be added in an amount of from about 1 ppm by volume to about 20 ppm by volume, based on the volume of the refined hydrocarbon stream. 
     
     
         20 . The method of  claim 1 , wherein the glyoxal further comprises a catalyst. 
     
     
         21 . The method of  claim 20 , wherein the catalyst is a quaternary ammonium salt. 
     
     
         22 . The method of  claim 21 , wherein the catalyst has formula I:
   R 1 R 2 R 3 R 4 N + X −   I
   wherein R 1 , R 2 , R 3  and R 4  are each independently an alkyl group having from 1 to 30 carbon atoms, an aryl group having from 6 to 30 carbon atoms or an arylalkyl group having from 7 to 30 carbon atoms; and X is a halide, sulfate, nitrate or carboxylate.   
     
     
         23 . The method of  claim 22 , wherein the quaternary ammonium salt is alkyl benzyl ammonium chloride or benzyl cocoalkyl (C 12 -C 18 ) dimethylammonium chloride. 
     
     
         24 . The method of  claim 21 , wherein the catalyst is present from about 0.01 to about 15 percent by weight based on the weight of glyoxal.