Novel Process for Removing Sulfur from Fuels

Abstract

A process for removing sulfur-containing compounds from fuel, said process comprising contacting the fuel in liquid phase with air to oxidise the sulfur containing compounds, said contacting being carried out in the presence of at least one transition metal oxide catalyst.

1 . A process for removing sulfur-containing compounds from fuel, said process comprising: 
 contacting the fuel in liquid phase with air to oxidise the sulfur-containing compounds, said contacting being carried out in the presence of at least one transition metal oxide catalyst.    
   
   
       2 . The process of claims  1 , wherein said contacting is carried out at a temperature range of between about 90° C. to 250° C.  
   
   
       3 . The process of  claim 1  or  2 , wherein said contacting is carried out at a temperature range of between about 110° C. to 190° C.  
   
   
       4 . The process of any one of  claims 1  to  3 , wherein said contacting is carried out at a temperature range of between about 130° C. to 180° C.  
   
   
       5 . The process of any one of  claims 1  to  4 , wherein said contacting is carried out at a temperature range of between about 130° C. to 160° C.  
   
   
       6 . The process of any one of  claims 1  to  5 , wherein said contacting is carried out at a pressure of about 1 bar.  
   
   
       7 . The process of any one of  claims 1  to  6 , wherein the catalyst is supported on a porous support.  
   
   
       8 . The process of  claim 7 , wherein the amount of catalyst supported on the porous support (catalyst loading) is in the range of about 1% to 17% by weight of the porous support.  
   
   
       9 . The process of  claim 7 , wherein the amount of catalyst supported on the porous support (catalyst loading) is in the range of 2% to 13% by weight of the porous support.  
   
   
       10 . The process of any one of  claims 7  to  9 , wherein the porous support comprises γ-alumina.  
   
   
       11 . The process of any one of  claims 1  to  10 , wherein the transition metal is selected from Groups 6, 7, 8 or 9 of the Periodic Table (IUPAC 1990).  
   
   
       12 . The process of  claim 11 , wherein the transition metal is selected from the group consisting of manganese, cobalt, iron, chromium and molybdenum.  
   
   
       13 . The process of any one of  claims 1  to  12 , further comprising: 
 adding a polar organic solvent to the treated fuel after contacting the fuel with air, thereby extracting the oxidised sulfur-containing compounds from the treated fuel, and    separating the polar organic solvent and the oxidised sulfur-containing compounds from the treated fuel.    
   
   
       14 . The process of  claim 13 , wherein the polar organic solvent comprises acetonitrile, N,N′-dimethyl-acetamide, N-methyl-pyrolidinone, trimethylphosphate, hexamethylphosphoric amide, methanol, ethanol, propanol, butanol, pyridine, propylene glycol, ethylene glycol, N,N′-dimethyl-formamide, 1-methyl-2-pyrrolidone, acetone and mixtures thereof.  
   
   
       15 . The process of  claim 13  or  14 , wherein 1 part by volume of polar organic solvent is added to between about 1 to 4 parts by volume of treated fuel.  
   
   
       16 . The process of any one of  claims 1  to  15 , further comprising treating the treated fuel with a basic adsorbent.  
   
   
       17 . The process of  claim 16 , wherein the basic adsorbent is selected from the group consisting of zeolites, activated carbon, and layered-double hydroxides (LDH).  
   
   
       18 . The process of  claim 16 , further comprising washing the basic adsorbent with a basic solution to regenerate the basic adsorbent.  
   
   
       19 . The process of any one of  claims 1  to  17 , wherein the untreated fuel comprises sulfur content in the range of between about 300 to 800 ppm.  
   
   
       20 . The process of any one of  claims 1  to  18 , wherein the fuel is diesel that has been treated in a hydro-desulfurisation process.  
   
   
       21 . The process of any one of  claims 1  to  19 , wherein the sulfur-containing compounds in the fuel comprise thiophenic compounds.  
   
   
       22 . The process of  claim 20 , wherein the thiophenic compounds are selected from the group consisting of thiophene, benzothiophene, dibenzothiophene, 4-methyl-dibenzothiophene, 4,6-dimethyl-dibenzothiophene and tribenzothiophene, and mono-, di-, tri-, and tetra-substituted compounds thereof.