Sulfur extraction from straight run gasoline

Abstract

A process for reducing the sulfur content of a gasoline fraction comprising one or more organic sulfur compounds including mercaptans, thiophenes, and mono- and di-sulfides, the process including: contacting a gasoline fraction having an initial organic sulfur content with a sulfuric acid-rich composition to extract organic sulfur compounds from the gasoline fraction and produce a gasoline fraction having reduced sulfur content and a sulfuric acid fraction having increased organic sulfur content; and separating the gasoline fraction having reduced organic sulfur content and the sulfuric acid-rich fraction having increased organic sulfur content.

1 . A process for reducing the sulfur content of a gasoline fraction comprising one or more organic sulfur compounds including mercaptans, thiophenes, and mono- and di-sulfides, the process comprising:
 contacting a gasoline fraction having an initial organic sulfur content with a sulfuric acid-rich composition to extract organic sulfur compounds from the gasoline fraction and produce a gasoline fraction having reduced sulfur content and a sulfuric acid fraction having increased organic sulfur content; and   separating the gasoline fraction having reduced organic sulfur content and the sulfuric acid-rich fraction having increased organic sulfur content.   
   
   
       2 . The process of  claim 1 , wherein the sulfuric acid-rich composition comprises at least 80 weight percent H 2 SO 4 . 
   
   
       3 . The process of  claim 1 , wherein the sulfuric acid-rich composition comprises fresh sulfuric acid, regenerated sulfuric acid, spent sulfuric acid, or combinations thereof. 
   
   
       4 . The process of  claim 1 , wherein a volume ratio of the sulfuric acid-rich composition to the gasoline fraction is within the range of 0.01 to 500. 
   
   
       5 . The process of  claim 1 , wherein the gasoline fraction having a reduced sulfur content comprises a total sulfur content of less than 20 mg/l. 
   
   
       6 . The process of  claim 1 , wherein a ratio of benzene and toluene in the gasoline fraction having reduced organic sulfur content to benzene and toluene in the gasoline fraction having an initial organic sulfur content is within the range from 0.95:1 to 1:1, based on weight. 
   
   
       7 . The process of  claim 1 , further comprising:
 contacting the gasoline fraction having reduced sulfur content with a second sulfuric acid-rich composition to produce a gasoline fraction having a further reduced organic sulfur content and a second sulfuric acid fraction having an increased organic sulfur content; and   separating the gasoline fraction having a further reduced organic sulfur content and the second sulfuric acid fraction having an increased organic sulfur content.   
   
   
       8 . The process of  claim 7 , wherein the second sulfuric acid-rich composition comprises at least 80 weight percent H 2 SO 4 . 
   
   
       9 . The process of  claim 7 , wherein the second sulfuric acid-rich composition comprises fresh sulfuric acid, regenerated sulfuric acid, spent sulfuric acid, or combinations thereof. 
   
   
       10 . The process of  claim 7 , wherein a volume ratio of the second sulfuric acid-rich composition to the gasoline fraction of reduced sulfur content is within the range of 0.01 to 500. 
   
   
       11 . The process of  claim 7 , wherein the gasoline fraction having a further reduced sulfur content comprises a total sulfur content of less than 10 mg/l. 
   
   
       12 . The process of  claim 1 , further comprising:
 reacting sulfur-containing hydrocarbons in the sulfuric acid fraction to form a hydrocarbon fraction and at least one of hydrogen sulfide and sulfur dioxide.   
   
   
       13 . The process of  claim 12 , further comprising:
 converting at least one of the hydrogen sulfide and the sulfur dioxide to form sulfuric acid.   
   
   
       14 . The process of  claim 1 , further comprising:
 separating the sulfuric acid-rich composition from the organic sulfur compounds; and   recycling the sulfuric acid-rich composition to the contacting step.   
   
   
       15 . The process of  claim 1 , wherein the gasoline fraction comprises straight run gasoline. 
   
   
       16 . The process of  claim 1 , wherein the contacting is performed for a period of time of 15 minutes or less. 
   
   
       17 . The process of  claim 1 , wherein the contacting is performed for a period of time of 5 minutes or less. 
   
   
       18 . The process of  claim 7 , wherein each of the contacting stages is performed for a period of time of 5 minutes or less.