Contaminant removal process

Abstract

Disclosed is a process comprising: step a) contacting a feed stream comprising a contaminant with an absorbent stream in a counter-current flow to produce a contaminant depleted product stream depleted in the molar quantity of the contaminant relative to the molar quantity of said contaminant in the feed stream, and a contaminant enriched absorbent stream enriched in the molar quantity of the contaminant relative to the molar quantity of said contaminant in the absorbent stream; and step b) treating the contaminant enriched absorbent stream to form a gaseous stream comprising said contaminant and a regenerated absorbent stream lean in the molar quantity of said contaminant relative to the molar quantity of said contaminant in the contaminant enriched absorbent stream; herein said absorbent stream comprises at least 15 wt. % of at least one compound (A) of general formula (I) or a mixture (M) comprising at least one compound (B) of general formula (II) and at least one compound (C) of general formula (III).

1 - 15 . (canceled) 
     
     
         16 . A mixture (M) comprising at least one substituted 2-pyrrolidone of general formula (II) [compound (B), herein after], herein below, and at least one amine compound of general formula (III) [compound (C), herein after], herein below: 
       
         
           
           
               
               
           
         
         wherein:
 each of R′, equal to or different from each other and at each occurrence, is independently selected from H or CH 3    
 j is an integer in the range from 0 to 3 
 each of R 3 , R 4 , R 5  and R 6 , equal to or different from each other and at each occurrence, is independently selected from H or CH 3 ; 
 q is an integer in the range from 0 to 1; p is an integer in the range from 1 to 6; with the proviso that when p=1 and q=0 then R 3  and R 4  are CH 3  and when p+q=2 then at least one of R 3 , R 4 , R 5  or R 6  is CH 3 ; 
 each of R 7 , R 8  and R 9 , equal to or different from each other and at each occurrence, is independently selected from H, C 1-10  alkyl, C 1-10  alkoxyalcohol or a C 1-10  alkanol group; with the proviso that at least one of R 7 , R 8  or R 9  is a C 1-10  alkoxyalcohol or a C 1-10  alkanol group. 
 
       
     
     
         17 . A composition comprising the mixture (M) as defined in  claim 16 . 
     
     
         18 . An absorbent stream comprising the mixture (M), as defined in  claim 16 . 
     
     
         19 . (canceled) 
     
     
         20 . A contaminant enriched absorbent stream comprising at least one absorbed contaminant selected from hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), carbon oxysulfide (COS), carbon disulfide (CS 2 ), disulfides or mercaptans, the absorbent stream comprising:
 i. at least 15 wt. %, relative to the total weight of the absorbent stream, of at least one substituted 2-pyrrolidone of general formula (I) [compound (A), herein after]:   
       
         
           
           
               
               
           
         
       
       wherein:
 each of R 1  and R 2 , equal to or different from each other and at each occurrence, is independently selected from H or CH 3 ; 
 each of R, equal to or different from each other and at each occurrence, is selected from H or CH 3 ; 
 i is an integer in the range from 0 to 3; 
 o is an integer in the range from 2 to 6; n is an integer in the range from 0 to 4; m is an integer in the range from 0 to 4; 
 
       or,
 ii. a mixture [mixture (M), herein after] comprising at least one substituted 2-pyrrolidone of general formula (II) [compound (B), herein after], herein below, and at least one amine compound of general formula (III) [compound (C), herein after], herein below: 
 
       
         
           
           
               
               
           
         
       
       wherein:
 each of R′, equal to or different from each other and at each occurrence, is independently selected from H or CH 3    
 j is an integer in the range from 0 to 3 
 each of R 3 , R 4 , R 5  and R 6 , equal to or different from each other and at each occurrence, is independently selected from H or CH 3 ; 
 q is an integer in the range from 0 to 1; p is an integer in the range from 1 to 6; with the proviso that when p=1 and q=0 then R 3  and R 4  are CH 3  and when p+q=2 then at least one of R 3 , R 4 , R 5  or R 6  is CH 3 ; 
 each of R 7 , R 8  and R 9 , equal to or different from each other and at each occurrence, is independently selected from H, C 1-10  alkyl, C 1-10  alkoxyalcohol or a C 1-10  alkanol group; with the proviso that at least one of R 7 , R 8  or R 9  is a C 1-10  alkoxyalcohol or a C 1-10  alkanol group.