Desulfurization and novel sorbents for same

Abstract

Particulate sorbent compositions comprising a mixture of zinc oxide, silica, alumina and a substantially reduced valence cobalt are provided for the desulfurization of a feedstream of cracked-gasoline or diesel fuels in a desulfurization zone by a process which comprises the contacting of such feedstreams in a desulfurization zone followed by separation of the resulting low sulfur-containing stream and sulfurized-sorbent and thereafter regenerating and activating the separated sorbent before recycle of same to the desulfurization zone.

1 . A sorbent composition for removal of sulfur from cracked gasolines and diesel fuels which is comprised of: 
 (a) zinc oxide;    (b) silica;    (c) alumina; and    (d) cobalt    wherein the valence of essentially all of the cobalt therein is zero such that the reduced cobalt-containing composition will affect the removal of sulfur from a stream of cracked-gasoline or diesel fuel when said stream is contacted with said reduced cobalt-containing composition, wherein said zinc oxide is present in an amount in the range of about 45 to about 60 weight percent, said silica is present in an amount in the range of about 15 to 60 weight percent, said alumina is present in an amount of 5.0 to about 15 weight percent and said cobalt is present in an amount in the range of about 15 to about 40 weight percent.    
     
     
         2 . A sorbent composition in accordance with  claim 1  wherein said zinc oxide is present in an amount of about 38 weight percent, said silica is present in an amount in the range of about 31 weight percent, said alumina is present in an amount of about 8 weight percent and said cobalt is present in an amount of about 30 weight percent.  
     
     
         3 . A sorbent composition in accordance with  claim 1  wherein said composition is a particulate in the form of one of granule, extrudate, tablet, sphere, pellet or microsphere.  
     
     
         4 . A sorbent composition suitable for removal of sulfur from cracked gasolines and diesel fuels which is comprised of: 
 (a) zinc oxide;    (b) silica;    (c) alumina; and    (d) cobalt    wherein the valence of essentially all of the cobalt therein is zero such that the reduced cobalt-containing composition will affect the removal of sulfur from a stream of cracked-gasoline or diesel fuel when said stream is contacted with said reduced cobalt-containing composition;    wherein said zinc oxide is present in amount in the range of about 10 to about 90 weight percent;    wherein said silica is present in an amount in the range of about 5 to about 85 weight percent;    wherein said alumina is present in an amount in the range from about 5.0 to about 30 weight percent; and    wherein at least a portion of the composition is calcined to convert at least a portion of the alumina to an aluminate.    
     
     
         5 . A sorbent composition suitable for removal of sulfur from cracked gasolines and diesel fuels consisting essentially of: 
 (a) zinc oxide;    (b) silica;    (c) alumina; and    (d) cobalt    wherein the valence of essentially all of the cobalt therein is zero such that the reduced cobalt-containing composition will affect the removal of sulfur from a stream of cracked-gasoline or diesel fuel when said stream is contacted with said reduced cobalt-containing composition;    wherein said zinc oxide is present in amount in the range of about 10 to about 90 percent;    wherein said silica is present in an amount in the range of about 5 to about 85 weight percent;    wherein said alumina is present in an amount in the range from about 5.0 to about 30 weight percent; and    wherein at least a portion of the composition is calcined to convert at least a portion of the alumina to an aluminate.    
     
     
         6 . A sorbent composition comprising: 
 (a) a support formed from a calcined mixture of zinc oxide, silica, and alumina; and    (b) cobalt.    
     
     
         7 . The sorbent composition of  claim 6 , wherein said cobalt is present in a substantially reduced valence state and in an amount which effects the removal of sulfur from a stream of gasoline and/or diesel fuel when contacted with the same under desulfurization conditions.  
     
     
         8 . The sorbent composition of  claim 6 , wherein said sorbent composition comprises substantially no cobalt oxide.  
     
     
         9 . The sorbent composition of  claim 6 , wherein said cobalt is incorporated on and/or in said support.  
     
     
         10 . The sorbent composition of  claim 6 , wherein said cobalt is impregnated on and/or in said support.  
     
     
         11 . The sorbent composition of  claim 6 , wherein said silica is selected from the group consisting of diatomite, silicalite, silica colloid, flame-hydrolyzed silica, hydrolyzed silica, silica gel, precipitated silica, and combinations of two or more thereof.  
     
     
         12 . The sorbent composition of  claim 11 , wherein said silica comprises diatomite.  
     
     
         13 . The sorbent composition of  claim 6 , wherein said alumina is selected from the group consisting of colloidal aluminas, aluminas produced by the dehydration of alumina hydrates, and combinations thereof.  
     
     
         14 . The sorbent composition of  claim 6 , wherein at least a portion of said alumina is present as an aluminate due to calcination of said support.  
     
     
         15 . The sorbent composition of  claim 6 , wherein said zinc oxide is present in an amount in the range of about 45 to about 60 weight percent, said silica is present in an amount in the range of about 15 to 60 weight percent, said alumina is present in an amount of 5.0 to about 15 weight percent and said cobalt is present in an amount in the range of about 15 to about 40 weight percent.  
     
     
         16 . A sorbent composition comprising: 
 (a) zinc oxide;    (b) silica;    (c) an aluminate; and    (d) cobalt.    
     
     
         17 . The sorbent composition of  claim 16 , wherein said cobalt is present in a substantially reduced valence state and in an amount which effects the removal of sulfur from a stream of gasoline and/or diesel fuel when contacted with the same under desulfurization conditions.  
     
     
         18 . The sorbent composition of  claim 16 , wherein said zinc oxide, silica, and aluminate are intimately mixed to form a support.  
     
     
         19 . The sorbent composition of  claim 18 , wherein said cobalt is present on and/or in said support.  
     
     
         20 . The sorbent composition of  claim 16 , wherein said zinc oxide is present in an amount in the range of about 45 to about 60 weight percent, said silica is present in an amount in the range of about 15 to 60 weight percent, said aluminate is present in an amount of 5.0 to about 15 weight percent and said cobalt is present in an amount in the range of about 15 to about 40 weight percent.  
     
     
         21 . The sorbent composition of  claim 16 , wherein at least a portion of the aluminate is formed by the calcination of alumina.  
     
     
         22 . The sorbent composition of  claim 21 , wherein said alumina is selected from the group consisting of colloidal aluminas, aluminas produced by the dehydration of alumina hydrates, and combinations thereof.  
     
     
         23 . The sorbent composition of  claim 16 , wherein said silica is selected from the group consisting of diatomite, silicalite, silica colloid, flame-hydrolyzed silica, hydrolyzed silica, silica gel, precipitated silica, and combinations of two or more thereof.  
     
     
         24 . The sorbent composition of  claim 23 , wherein said silica comprises diatomite.  
     
     
         25 . The sorbent composition of  claim 16 , wherein said sorbent composition comprises substantially no cobalt oxide.