Process for reducing the level of elemental sulfur in hydrocarbon streams

Abstract

A process for reducing the level of elemental sulfur and organic sulfur pick-up by refined hydrocarbon streams such as gasoline, diesel, jet fuel, kerosene or fuel additives such as ethers or iso-octane that are transported through a pipeline used to transport various sulfur-containing petroleum streams. The oxygen level in the hydrocarbon stream of interest to be pipelined as well as in at least the first hydrocarbon stream sequenced immediately ahead of the hydrocarbon stream of interest is reduced.

1 . A process for reducing the level of elemental and organic sulfur picked-up in a hydrocarbon stream being transported in a pipeline that is used to transport various sulfur-containing petroleum streams, which process comprises: 
 (i) reducing the level of oxygen to less than about 30 wppm in the hydrocarbon stream of interest to be transported through a pipeline; and    (i) reducing the level of oxygen to less than about 30 wppm in at least the first hydrocarbon stream to be transported in a pipeline immediately ahead of said hydrocarbon stream of interest.    
     
     
         2 . The process of  claim 1  wherein the oxygen level in the hydrocarbon stream of interest as well as in the first two hydrocarbon streams transported immediately ahead of the hydrocarbon stream of interest is reduced.  
     
     
         3 . The process of  claim 1  wherein the oxygen level in the hydrocarbon stream of interest as well as in the first three hydrocarbon streams transported immediately ahead of the hydrocarbon stream of interest is reduced.  
     
     
         4 . The process of  claim 1  wherein the oxygen level in the hydrocarbon stream of interest to be transported in a pipeline and at least the first hydrocarbon stream transported ahead of said hydrocarbon stream of interest is reduced to less than about 10 wppm.  
     
     
         5 . The process of  claim 1  wherein the oxygen level in the hydrocarbon stream of interest to be transported in a pipeline and at least the first hydrocarbon stream transported ahead of said hydrocarbon stream of interest is reduced to less than about 1 wppm.  
     
     
         6 . The process of  claim 1  wherein said hydrocarbon stream of interest and at least the first hydrocarbon streams transported ahead of said hydrocarbon stream of interest are treated with a mercaptan compound to reduce the oxygen level prior to the treated hydrocarbon streams being transported through a pipeline.  
     
     
         7 . The process of  claim 1  wherein said hydrocarbon stream of interest and at least the first hydrocarbon stream transported ahead of said hydrocarbon stream of interest are treated with said mercaptan compound while being transported through a pipeline.  
     
     
         8 . The process of  claim 5  wherein said mercaptan compound is represented by the formula RSH, where R represents an organic radical that may be alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl or arylalkyl having from 1 to about 16 carbon atoms.  
     
     
         9 . The process of  claim 7  wherein said mercaptan compound is used in a concentration of from about 1 to about 1000 wppm.  
     
     
         10 . The process of  claim 1  wherein said hydrocarbon stream of interest and at least the first hydrocarbon stream transported immediately ahead of said hydrocarbon stream of interest are purged with nitrogen to reduce the oxygen level of the treated stream.  
     
     
         11 . The process of  claim 1  wherein said hydrocarbon stream of interest and at least the first hydrocarbon stream transported immediately ahead of said hydrocarbon stream of interest are selected from the group consisting of gasoline boiling range streams and distillate boiling range streams.  
     
     
         12 . The process of  claim 1  wherein one of the hydrocarbon streams is a dialkyl ether having 1 to 7 carbon atoms in each alkyl group.  
     
     
         13 . The process of  claim 12  wherein the dialkyl ether is selected from the group consisting of methyl tertiary-butyl ether, methyl tertiary-amyl ether, methyl tertiary-hexyl ether, ethyl tertiary-butyl ether, n-propyl tertiary-butyl ether, and isopropyl tertiary-amyl ether.