Contaminant removal process

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;
• wherein said absorbent stream comprises:
• i. at least 15 weight percent (wt. % herein after), 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 R1 and R2, equal to or different from each other and at each occurrence, is independently selected from H or CH3;
• each of R, equal to or different from each other and at each occurrence, is selected from H or CH3;
• 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 CH3
• j is an integer in the range from 0 to 3
• each of R3, R4, R5 and R6, equal to or different from each other and at each occurrence, is independently selected from H or CH3;
• 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 R3 and R4 are CH3 and when p+q=2 then at least one of R3, R4, R5 or R6 is CH3;
• each of R7, R8 and R9, equal to or different from each other and at each occurrence, is independently selected from H, C1-10 alkyl, C1-10 alkoxyalcohol or a C1-10 alkanol group;
• with the proviso that at least one of R7, R8 or R9 is a C1-10 alkoxyalcohol or a C1-10 alkanol group.