Method for removing organic sulfur from heterocyclic sulfur-containing organic compounds

Abstract

A method for removing sulfur from liquid compositions containing aliphatic or cylic organic sulfur-containing compounds, e.g., dibenzothiophene includes activating the sulfur-containing compound by oxidizing either the organic sulfur or adjacent carbon atoms in the presence of a suitable active biocatalyst (ie., microorganism, enzyme, etc.) followed by treating of the activated compound by techniques such as fluidized catalytic cracking so as to remove the sulfur therefrom.

What is claimed is:  
     
       1. A method for removing organic sulfur from a liquid composition containing aliphatic and/or heterocyclic sulfur-containing organic compounds comprising: 
       (a) providing a liquid composition containing a sulfur-containing organic compound;  
       (b) activating said sulfur-containing organic compound by oxidizing at least one of (i) a sulfur atom or (ii) a carbon atom adjacent to the sulfur atom so as to provide an activated compound said oxidizing step is performed in the presence of an active biocatalyst capable of oxidizing sulfur to sulfoxide, sulfone, or sulfonic acid; and  
       (c) removing sulfur from the activated compound.  
     
     
       2. The method according to claim  1  wherein the biocatalyst is a whole-cell microorganism, lyophilized cell or enzyme 
     
     
       3. The method according to claim  1  wherein the biocatalyst is ATCC 53968 or  Rhodococcus erythropilis.    
     
     
       4. The method according to claim  1  wherein activating step (b) comprises the 1S enzymatic step but not the 4S enzymatic step. 
     
     
       5. The method according to claim  4  wherein activating step (b) further comprises the 2S enzymatic step. 
     
     
       6. The method according to claim  5  wherein activating step (b) further comprises a 3S enzymatic step. 
     
     
       7. The method according to any one of claims  1 - 6  wherein treating step (c) comprises fluidized catalytic cracking of the liquid composition. 
     
     
       8. The method according to any one of claims  1 - 6  wherein step (c) comprises the use for elevated temperature and/or pressure reaction systems with or without the use of a chemical catalyst. 
     
     
       9. The method according to claim  1  wherein the liquid composition comprises dibenzothiophene, benzothiophene and aliphatic or heterocyclic derivatives thereof. 
     
     
       10. The method according to claim  1  wherein the liquid composition comprises a fossil fuel. 
     
     
       11. The method according to claim  10  wherein the stream comprises vacuum gas oil. 
     
     
       12. The method according to claim  1  wherein step (b) employs an aqueous medium. 
     
     
       13. The method according to claim  1  wherein the step (b) employs a non-aqueous medium. 
     
     
       14. A method for making FCCU gasoline form a feed stream containing at least one organic sulfur-containing compound comprising: 
       (a) activating the at least one organic sulfur-containing compound by oxidizing at least one of (i) a sulfur atom or (ii) a carbon atom adjacent to the sulfur atom in the presence of a biocatalyst capable of oxidizing sulfur to sulfoxide, sulfone, or sulfonic acid; and  
       (b) removing sulfur from the activated compound.  
     
     
       15. A product produced by the process according to claim  1 . 
     
     
       16. A FCCU fuel produced by the process according to claim  7 .