Hydrocarbon desulfurization with pre-oxidation of organosulfur compounds

Abstract

A system for removing sulfur from a hydrocarbon-containing fluid stream wherein desulfurization is enhanced by oxidizing certain organosulfur compounds of the hydrocarbon-containing fluid stream prior to desulfurization.

What is claimed is:  
     
         1 . A desulfurization process comprising the steps of: 
 (a) contacting a hydrocarbon-containing fluid containing sulfur compounds with an oxidizing agent under oxidation conditions sufficient to oxidize at least a portion of said sulfur compounds, thereby providing an oxidized hydrocarbon-containing fluid comprising oxidized sulfur compounds; and    (b) contacting said oxidized hydrocarbon-containing fluid with a sorbent comprising a promoter metal component and zinc oxide under desulfurization conditions sufficient to remove at least a portion of said oxidized sulfur compounds from said oxidized hydrocarbon-containing fluid.    
     
     
         2 . A desulfurization process in accordance with  claim 1 , wherein said oxidizing agent is selected from the group consisting of bromine, bromates, chlorinated isocyanurates, chlorates, chromates, dichromates, hydroperoxides, hypochlorites, inorganic peroxides, ketone peroxides, nitrates, nitric acid, nitrites, perborates, perchlorates, perchloric acid, periodates, permanganates, peroxides, peroxyacids, persulphates, and mixtures thereof.  
     
     
         3 . A desulfurization process in accordance with  claim 1 , wherein said oxidizing agent comprises a peroxide.  
     
     
         4 . A desulfurization process in accordance with  claim 1 , wherein said oxidizing agent comprises an organic peroxide.  
     
     
         5 . A desulfurization process in accordance with  claim 1 , wherein said oxidizing agent comprises a peroxyacid.  
     
     
         6 . A desulfurization process in accordance with  claim 1 , wherein said oxidizing agent is a mixture of peroxyacid and acetic acid.  
     
     
         7 . A desulfurization process in accordance with  claim 1 , wherein said hydrocarbon-containing fluid is selected from the group consisting of middle distillates, cracked-gasoline, gasoline, and mixtures thereof, and wherein said hydrocarbon-containing fluid comprises at least about 50 ppmw of said sulfur compounds.  
     
     
         8 . A desulfurization process in accordance with  claim 7 , wherein said hydrocarbon-containing fluid is a middle distillate boiling in the range of from about 300 to about 750° F. and having a mid-boiling point of more than about 350° F., and wherein at least about 50 weight percent of said sulfur compounds are organosulfur compounds.  
     
     
         9 . A desulfurization process in accordance with  claim 8 , wherein said hydrocarbon-containing fluid is diesel fuel boiling in the range of from 375 to 700° F. and having a mid-boiling point of at least 500° F., wherein said organosulfur compounds include thiophenes, and wherein at least a portion of said thiophenes are oxidized to their corresponding sulfones or sulfoxides during step (a).  
     
     
         10 . A desulfurization process in accordance with  claim 1 , wherein said sulfur compounds include 4,6-dimethyldibenzothiophene and wherein at least a portion of the 4,6-dimethyldibenzothiophene is oxidized into its corresponding sulfone or sulfoxide during step (a).  
     
     
         11 . A desulfurization process in accordance with  claim 1 , wherein said oxidation conditions include an oxidation temperature in the range of from about 50 to about 200° F. and an oxidation pressure in the range of from about 0 to about 50 psia, and wherein said desulfurization conditions include a desulfurization temperature in the range of from about 250 to about 1200° F. and a desulfurization pressure in the range of from about 25 to about 750 psig.  
     
     
         12 . A desulfurization process in accordance with  claim 1 , wherein said sorbent comprises said promoter metal component in an amount in the range of from about 5 to about 80 weight percent and said zinc oxide in an amount in the range of from about 5 to about 80 weight percent.  
     
     
         13 . A desulfurization process in accordance with  claim 1 , wherein at least a portion of said zinc oxide is converted to zinc sulfide with sulfur from said oxidized sulfur compounds during step (b).  
     
     
         14 . A desulfurization process in accordance with  claim 1 , wherein said promoter metal component comprises a promoter metal selected from the group consisting of nickel, cobalt, iron, manganese, copper, zinc, molybdenum, tungsten, silver, antimony, and vanadium.  
     
     
         15 . A desulfurization process in accordance with  claim 14 , wherein said promoter metal is nickel.  
     
     
         16 . A desulfurization process in accordance with  claim 1 , wherein said promoter metal component comprises a substitutional solid metal solution characterized by the formula M A Zn B , wherein M is a promoter metal and A and B are each numerical values in the range of 0.01 to 0.99.  
     
     
         17 . A desulfurization process in accordance with  claim 4 , wherein A is in the range of from about 0.70 to about 0.97 and B is in the range of from about 0.03 to about 0.30.  
     
     
         18 . A desulfurization process in accordance with  claim 17 , wherein said promoter metal is nickel.  
     
     
         19 . A desulfurization process in accordance with  claim 1 , wherein said sorbent further comprises perlite.  
     
     
         20 . A desulfurization process in accordance with  claim 1 , wherein said sorbent further comprises an aluminate.  
     
     
         21 . A desulfurization process in accordance with  claim 20 , wherein said aluminate is a promoter metal-zinc aluminate substitutional solid solution characterized by the formula M Z Zn (1−Z) Al 2 O 4 , wherein M is a promoter metal and Z is a numerical value in the range of from 0.01 to 0.99.  
     
     
         22 . A desulfurization process comprising the steps of: 
 (a) contacting a middle distillate containing thiophene compounds with an oxidizing agent under oxidizing conditions sufficient to convert at least a portion of said thiophene compounds to oxidized sulfur compounds selected from the group consisting of sulfones, sulfoxides, and mixtures thereof, thereby providing an oxidized middle distillate; and    (b) contacting said oxidized middle distillate with a sorbent comprising a promoter metal component and zinc oxide under desulfurization conditions sufficient to remove at least a portion of said oxidized sulfur compounds from said oxidized middle distillate.    
     
     
         23 . A desulfurization process in accordance with  claim 22 , wherein said middle distillate comprises at least about 50 ppmw of sulfur compounds, and wherein at least about 50 weight percent of said sulfur compounds are organosulfur compounds.  
     
     
         24 . A desulfurization process in accordance with  claim 23 , wherein said thiophene compounds include dimethyldibenzothiophenes and wherein said oxidizing agent is selected from the group consisting of bromine, bromates, chlorinated isocyanurates, chlorates, chromates, dichromates, hydroperoxides, hypochlorites, inorganic peroxides, ketone peroxides, nitrates, nitric acid, nitrites, perborates, perchlorates, perchloric acid, periodates, permanganates, peroxides, peroxyacids, persulphates, and mixtures thereof.  
     
     
         25 . A desulfurization process in accordance with  claim 24 , wherein said thiophene compounds include 4,6-dimethyldibenzothiophene and wherein said oxidizing agent is a peroxide.  
     
     
         26 . A desulfurization process in accordance with  claim 22 , wherein said middle distillate boils in the range of from about 300 to about 750° F., has a mid-boiling point of at least about 350° F., and comprises in the range of from about 100 to about 50,000 ppmw of sulfur compounds, and wherein at least about 75 weight percent of said sulfur compounds are organosulfur compounds.  
     
     
         27 . A desulfurization process in accordance with  claim 26 , wherein said middle distillate is diesel fuel boiling in the range of from 375 to 700° F., having a mid-boiling point of at least 500° F., having an API gravity in the range of from 30 to 38, and having a minimum flash point of at least 100° F.  
     
     
         28 . A desulfurization process in accordance with  claim 22 , wherein said promoter metal component is a reduced-valence promoter metal component.  
     
     
         29 . A desulfurization process in accordance with  claim 22 , wherein said promoter metal component comprises said promoter metal component in an amount in the range of from about 5 to about 80 weight percent and said zinc oxide in an amount in the range of from about 5 to about 80 weight percent.  
     
     
         30 . A desulfurization process in accordance with  claim 29 , wherein said promoter metal component comprises a promoter metal selected from the group consisting of nickel, cobalt, iron, manganese, copper, zinc, molybdenum, tungsten, silver, antimony, and vanadium.  
     
     
         31 . A desulfurization process in accordance with  claim 30 , wherein said promoter metal is nickel.  
     
     
         32 . A desulfurization process in accordance with  claim 22 , wherein said promoter metal component comprises a substitutional solid metal solution characterized by the formula M A Zn B , wherein M is a promoter metal and A and B are each numerical values in the range of 0.01 to 0.99.  
     
     
         33 . A desulfurization process in accordance with  claim 32 , wherein said promoter metal is selected from the group consisting of nickel, cobalt, iron, manganese, copper, zinc, molybdenum, tungsten, silver, antimony, and vanadium, wherein A is in the range of from about 0.70 to about 0.97, and wherein B is in the range of from about 0.03 to about 0.30.  
     
     
         34 . A desulfurization process in accordance with  claim 33 , wherein said promoter metal is nickel, wherein A is in the range of from about 0.85 to about 0.95, and wherein B is in the range of from about 0.05 to about 0.15.  
     
     
         35 . A desulfurization process comprising the steps of: 
 (a) contacting a hydrocarbon-containing fluid containing sulfur compounds with an oxidizing agent under oxidation conditions sufficient to oxidize at least a portion of said sulfur compounds, thereby providing an oxidized hydrocarbon-containing fluid comprising oxidized sulfur compounds;    (b) contacting said oxidized hydrocarbon-containing fluid with a sorbent comprising a promoter metal component and zinc oxide under desulfurization conditions sufficient to remove at least a portion of said oxidized sulfur compounds from said oxidized hydrocarbon-containing fluid, thereby providing a desulfurized hydrocarbon-containing fluid and a sulfur-loaded sorbent;    (c) contacting at least a portion of said sulfur-loaded sorbent with an oxygen-containing regeneration stream under regeneration conditions sufficient to remove sulfur from said sulfur-loaded sorbent and oxidize said promoter metal component, thereby providing a regenerated sorbent comprising an oxidized promoter metal component; and    (d) contacting at least a portion of said regenerated sorbent with a hydrogen-containing regeneration stream under reducing conditions sufficient to reduce at least a portion of said oxidized promoter metal component, thereby providing a reduced sorbent.    
     
     
         36 . A desulfurization process in accordance with  claim 35 , wherein said oxidizing agent is selected from the group consisting of bromine, bromates, chlorinated isocyanurates, chlorates, chromates, dichromates, hydroperoxides, hypochlorites, inorganic peroxides, ketone peroxides, nitrates, nitric acid, nitrites, perborates, perchlorates, perchloric acid, periodates, permanganates, peroxides, peroxyacids, persulphates, and mixtures thereof.  
     
     
         37 . A desulfurization process in accordance with  claim 36 , wherein said hydrocarbon-containing fluid is selected from the group consisting of middle distillates, cracked-gasoline, gasoline, and mixtures thereof.  
     
     
         38 . A desulfurization process in accordance with  claim 37 , wherein said hydrocarbon-containing fluid comprises at least about 50 ppmw of said sulfur compounds, and wherein at least about 50 weight percent of said sulfur compounds are organosulfur compounds.  
     
     
         39 . A desulfurization process in accordance with  claim 35 , wherein said oxidizing agent is a peroxide.  
     
     
         40 . A desulfurization process in accordance with  claim 39 , wherein said hydrocarbon-containing fluid is a middle distillate boiling in the range of from about 300 to about 750° F. and having a mid-boiling point of more than about 350° F.  
     
     
         41 . A desulfurization process in accordance with  claim 40 , wherein said hydrocarbon-containing fluid comprises in the range of from about 100 to about 50,000 ppmw of said sulfur compounds, and wherein at least about 75 weight percent of said sulfur compounds are organsulfur compounds.  
     
     
         42 . A desulfurization process in accordance with  claim 41 , wherein said organosulfur compounds include thiophenes.  
     
     
         43 . A desulfurization process in accordance with  claim 35 , wherein step (d) includes converting at least a portion of said zinc oxide to zinc sulfide, and wherein step (c) includes converting at least a portion of said zinc sulfide to zinc oxide.  
     
     
         44 . A desulfurization process in accordance with  claim 35 , further comprising the step of: 
 (e) contacting said reduced sorbent with said oxidized hydrocarbon-containing fluid under said desulfurization conditions.    
     
     
         45 . A desulfurization process in accordance with  claim 35 , wherein said promoter metal component comprises a promoter metal selected from the group consisting of nickel, cobalt, iron, manganese, copper, zinc, molybdenum, tungsten, silver, antimony, and vanadium.  
     
     
         46 . A desulfurization process in accordance with  claim 45 , wherein said promoter metal component comprises a substitutional solid metal solution characterized by the formula M A Zn B , wherein M is said promoter metal and A and B are each numerical values in the range of 0.01 to 0.99.  
     
     
         47 . A desulfurization process in accordance with  claim 46 , wherein said oxidized promoter metal component comprises a substitutional solid metal oxide solution characterized by the formula M X Zn Y O, wherein M is said promoter metal and X and Y are each numerical values in the range of from 0.01 to 0.99.  
     
     
         48 . A desulfurization process in accordance with  claim 47 , wherein step (d) includes converting at least a portion of said substitutional solid metal oxide solution to said substitutional solid metal solution.  
     
     
         49 . A desulfurized hydrocarbon-containing fluid produced by the process of  claim 1 .  
     
     
         50 . A desulfurized middle distillate produced by the process of  claim 22 .  
     
     
         51 . A desulfurized hydrocarbon-containing fluid produced by the process of  claim 35.