Method for Reducing Mercaptans in Hydrocarbons

Abstract

A method for reducing mercaptan concentration in a liquid hydrocarbon, comprising: contacting a mercaptan-rich liquid hydrocarbon having a first concentration of mercaptan sulfur with a composition comprising an oxidizing agent and water wherein the molar ratio of the oxidizing agent to mercaptan sulfur in the mercaptan-rich liquid hydrocarbon is from 3:1 to 10:1; and separating the water from the liquid hydrocarbon to yield a mercaptan-depleted liquid hydrocarbon having a second concentration of mercaptan sulfur, the second concentration being less than the first concentration; wherein a major amount of mercaptan compounds in the mercaptan-rich liquid hydrocarbon are converted to at least one sulfur oxoacid or salt thereof, having the formula: [RSO x ] n Y wherein R is a hydrocarbyl group; x is an integer from 1 to 3; n is 1 or 2; and Y is hydrogen, an alkaline metal, or alkaline earth metal.

1 . A method for reducing mercaptan concentration in a liquid hydrocarbon, comprising:
 (a) contacting a mercaptan-rich liquid hydrocarbon having a first concentration of mercaptan sulfur with a composition comprising an oxidizing agent and water wherein the molar ratio of the oxidizing agent to mercaptan sulfur in the mercaptan-rich liquid hydrocarbon is from 3:1 to 10:1; and   (b) separating the water from the liquid hydrocarbon to yield a mercaptan-depleted liquid hydrocarbon having a second concentration of mercaptan sulfur, the second concentration being less than the first concentration;   wherein a major amount of mercaptan compounds in the mercaptan-rich liquid hydrocarbon are converted to at least one sulfur oxoacid or salt thereof, having the formula:
   [RSO x ] n Y 
   wherein R is a hydrocarbyl group; x is an integer from 1 to 3; n is 1 or 2; and Y is hydrogen, an alkaline metal, or alkaline earth metal.   
     
     
         2 . The method of  claim 1 , wherein the liquid hydrocarbon is a crude oil. 
     
     
         3 . The method of  claim 1 , wherein the liquid hydrocarbon is a jet fuel. 
     
     
         4 . The method of  claim 1 , wherein the liquid hydrocarbon contains at least 200 ppm mercaptan sulfur. 
     
     
         5 . The method of  claim 1 , wherein the oxidizing agent is an alkali or alkaline earth metal hypochlorite salt. 
     
     
         6 . The method of  claim 1 , wherein at least 60 percent by weight of the mercaptan compounds in the mercaptan-rich liquid hydrocarbon are converted to the at least one sulfur oxoacid or salt thereof. 
     
     
         7 . The method of  claim 1 , wherein at least 70 percent by weight of the mercaptan compounds in the mercaptan-rich liquid hydrocarbon are converted to the at least one sulfur oxoacid or salt thereof. 
     
     
         8 . The method of  claim 1 , wherein the mercaptan-depleted liquid hydrocarbon contains less than 50 ppm mercaptan sulfur. 
     
     
         9 . The method of  claim 1 , wherein the mercaptan-depleted liquid hydrocarbon contains less than 10 ppm mercaptan sulfur. 
     
     
         10 . The method of  claim 1 , wherein the mercaptan-depleted liquid hydrocarbon contains less than 1 ppm mercaptan sulfur. 
     
     
         11 . The method of  claim 1 , wherein the oxidizing agent is a halide-containing oxidizing agent and the mercaptan-depleted liquid hydrocarbon is further contacted with an aqueous caustic solution under conditions to reduce the halide concentration in the mercaptan-depleted liquid hydrocarbon. 
     
     
         12 . The method of  claim 11 , wherein the aqueous caustic solution is selected from alkali and alkaline earth metal hydroxide solutions, and mixtures thereof. 
     
     
         13 . The method of  claim 11 , wherein the aqueous caustic solution further comprises a low molecular weight alkanol. 
     
     
         14 . The method of  claim 11 , wherein the aqueous caustic solution further comprises a phase transfer catalyst.