Method for Desulfurization of Hydrocarbon Oils

Abstract

Provided herein are processes for desulfurization of a hydrocarbon oil. The processes comprise providing a hydrocarbon oil comprising sulfur impurities and mixing the oil with a phase transfer agent and a source of hypochlorite ions to provide a mixture. The mixture separates into an aqueous hypochlorite phase and a non-polar oil phase. The hypochlorite phase may then be removed from the oil phase, and the oil phase centrifuged and separated from any precipitate, thereby providing a cleaned oil phase.

1 . A process for desulfurizing a hydrocarbon oil comprising:
 Providing a hydrocarbon oil comprising sulfur impurities,   mixing the hydrocarbon oil with a phase transfer agent and a hypochlorite ion source to provide a mixture, and   allowing the mixture to separate into an aqueous hypochlorite phase and a non-polar oil phase.   
     
     
         2 . The process of  claim 1 , further comprising agitating the mixture prior to allowing the mixture to separate. 
     
     
         3 . The process of  claim 1 , wherein the phase transfer agent comprises one or more cationic, anionic and nonionic surfactants. 
     
     
         4 . The process of  claim 3 , wherein the phase transfer agent comprises one or more quaternary ammonium salts, quaternary phosphonium salts and crown ethers. 
     
     
         5 . The process of  claim 4 , wherein the phase transfer agent comprises one or more of tetrabutyl ammonium bromide, tetrabutyl ammonium hydrogen sulfate, tributylmethyl ammonium chloride, benzyltrimethyl ammonium chloride, benzyltriethyl ammonium chloride, methyltricaprylyl ammonium chloride, dodecyltrimethyl ammonium bromide, tetraoctyl ammonium bromide, cetyltrimethyl ammonium chloride, cetyltrimethylammonium bromide and trimethyloctadecyl ammonium hydroxide. 
     
     
         6 . The process of  claim 5 , wherein the phrase transfer agent comprises cetyltrimethylammonium bromide (CETAB), tetrabutylammonium bromide (TBAB) or a combination of these. 
     
     
         7 . The process of  claim 1 , wherein the phase transfer agent is provided in an amount of from about 0.01 wt % to about 1 wt % based upon the weight of the hypochlorite ion source. 
     
     
         8 . The process of  claim 1 , wherein the phase transfer agent is provided in solution. 
     
     
         9 . The process of  claim 8 , wherein the phase transfer agent is provided in solution with water, in a concentration of from about 0.05 wt % to about 0.5 wt %. 
     
     
         10 . The process of  claim 1 , wherein the hypochlorite ion source comprises sodium hypochlorite, calcium hypochlorite, or a combination of these. 
     
     
         11 . The process of  claim 1 , further comprising separating the phases. 
     
     
         12 . The process of  claim 11 , wherein the hydrocarbon oil and/or hypochlorite ion source is/are recycled to the process. 
     
     
         13 . The process of  claim 11 , wherein the hydrocarbon oil and/or hypochlorite ion source is/are recycled to a different process/point of use. 
     
     
         14 . The process of  claim 11 , further comprising subjecting the separated hydrocarbon oil phase to further processing. 
     
     
         15 . The process of  claim 14 , wherein the hydrocarbon oil is washed with a polar solvent. 
     
     
         16 . The process of  claim 1 , wherein the residual sulfur content of the hydrocarbon oil after the process is less than about 3 wt %. 
     
     
         17 . The process of  claim 16 , wherein the residual sulfur content of the hydrocarbon oil after the process is less than about 2.5 wt %. 
     
     
         18 . The process of  claim 14 , wherein the residual sulfur content of the hydrocarbon oil after the process is less than about 2.0 wt %.