Procedure for the removal of fluoridated pollutants from hydrocarbon effluents

Abstract

A process is disclosed for removing fluoridated compounds from any organic medium, for example from alkylation (“alkylated”) gasoline, which can be applied at the exit of the alkylation process or inside the distillation column of the alkylation process. The process uses extractant chemical agents based on ionic liquids, of general formula C+A−, where C+ represents an organic or inorganic cation, specifically imidazolium, pyridinium, or ammonium salts, while the anion A− represents the halide-type derivatives, iron (III) salts, aluminum (III) salts, acetate, benzoate-acetates, benzoates, hexafluorophosphate, tetra-chloroborate, triflates, bis-triflates and trifluoroacetates. These ionic liquids act as extractant agents to remove fluoridated compounds from the hydrocarbon streams that are produced in the process of alkylation of isubutane with butenes, through a liquid-liquid extraction process, with a reduction of more than 80% in the content of contaminants like organofluoridated hydrocarbons.

1 . A process for removing fluoridated compounds of formula XF, present in hydrocarbon effluents and in alkylation gasoline, where X represents: —H, —CH 3 , —C(CH 3 ) 3 , —(CH 2 ) 7 CH 3 , —C(CH) 2 (CH 3 ) 4 , —CH 2 (CH 2 ) 10 CH 3 , (CH 3 ) 3 CCH 2 CH(CH 3 ) 2 , CH 3 CH 2 C(CH 3 )═CH 2 , CH 3 (CH 2 ) 4 CH(CH 3 ) 2 , or (CH 3 ) 5 (CH 2 ) 3 , said process comprising: 1. synthesizing an ionic liquid; and 2. contacting the ionic liquid with the alkylation effluent or gasoline to effect a liquid-liquid extraction. 
     
     
         2 . The process according to  claim 1 , wherein the ionic liquid consists of
 a) a 5- or 6-membered nitrogenous heterocyclic cation containing one or two nitrogen atoms inserted in the ring, as represented by   
       
         
           
           
               
               
           
         
         or a cation formed by a quaternary ammonium group, as represented by 
       
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3  and R 4  represent a hydrogen atom, an alkyl substituent, or organic group functionalized with a chain of 1 to 10 carbon atoms; and 
         b) an organic or inorganic anion including: halogens, transition metal salts, acetates, benzoates, hexafluorophosphate, tetrafluoroborate, triflates, bistriflates and trifluoroacetates. 
       
     
     
         3 . The process according to  claim 1 , wherein a ratio of ionic liquid to hydrocarbon is between 1:1 and 1:100. 
     
     
         4 . The process according to  claim 1 , wherein a temperature is between 25° C. and 45° C. during the extraction. 
     
     
         5 . The process according to  claim 1 , wherein an extraction capacity of fluoridated compounds is between 50% and 99%. 
     
     
         6 . The process according to  claim 5 , wherein a number of extraction cycles performed to obtain the extraction capacity is from 1 to 50. 
     
     
         7 . The process according to  claim 5 , wherein the extraction capacity is obtained in an extraction time of 1 to 60 minutes per extraction. 
     
     
         8 . The process according to  claim 1 , wherein an extraction capacity of fluoridated compounds is 50% or more, wherein the process includes a batch mode with vigorous agitation or a continuous process mode that emulates an extraction column at an exit of a separation process for removal of the fluoridated compounds in line, from a liquid hydrocarbon stream that results from a process of alkylation of isobutanes with butenes. 
     
     
         9 . The process according to  claim 3 , wherein the ratio of ionic liquid to hydrocarbon is between 1:5 and 1:50. 
     
     
         10 . The process according to  claim 9 , wherein the ratio of ionic liquid to hydrocarbon is 1:10. 
     
     
         11 . The process according to  claim 6 , wherein the number of extraction cycles is between 1 to 20. 
     
     
         12 . The process according to  claim 7 , wherein the extraction time is 1 to 30 minutes per extraction.