Gas capture process

1. A process for the capture of CO 2 from gas streams, the process including contacting a CO 2 containing gas stream with a compound including:

a primary or non-sterically hindered secondary amine group and

at least one tertiary amine or sterically hindered secondary amine group;

wherein the primary or non-sterically hindered secondary amine and the nearest tertiary or sterically hindered secondary amine group are separated by a carbon chain including 3 or 4 carbon atoms and wherein the compound is a compound of Formula (I)

wherein

R 1 is represented by hydrogen, C 2 to C 6 alkanol or C 1 to C 6 alkyl;

R 2 is represented by hydrogen, C 1 to C 6 alkyl, C 2 to C 6 alkanol, —(CH 2 ) n —NR 6 R 7 , —(CH 2 ) p —COOH, —(CH 2 ) p COOQ, —(CH 2 ) p -heterocyclic ring containing one to four heteroatoms independently selected from nitrogen, oxygen and sulphur;

R 3 and R 5 are independently selected from hydrogen, C 1 to C 4 alkyl, C 2 to C 6 alkanol, —(CH 2 ) n —NR 8 R 9 ;

R 4 is represented by hydrogen, C 1 to C 6 alkyl, C 2 to C 6 alkanol, —(CH 2 ) n —NR 6 R 7 , —(CH 2 ) p —COOH, —(CH 2 ) p COOQ, —(CH 2 ) p —SO 3 H, —(CH 2 ) p SO 3 Q, —(CH 2 ) p —PO 3 H 2 , —(CH 2 ) p PO 3 Q s , —(CH 2 ) p -heterocyclic ring containing one to four heteroatoms independently selected from nitrogen, oxygen and sulphur;

x 0 or 1;

n is 2 to 6;

p is 1 to 6;

Q is hydrogen, a metal ion or R 16 R 17 R 18 R 19 N + ;

s is 1 or 2

R 6 and R 7 are independently selected from hydrogen, alkyl, alkanol, alkylamine or R 6 and R 7 together with the nitrogen atom to which they are attached form a ring structure

R 8 and R 9 are independently selected from C 1 to C 6 alkyl, C 2 to C 6 alkanol, C 2 to C 6 alkylamine, —(CH 2 ) n —NR 6 R 7 , —(CH 2 ) p —COOH, —(CH 2 ) p COOQ, —(CH 2 ) p —SO 3 H, —(CH 2 ) p SO 3 Q, —(CH 2 ) p —PO 3 H 2 , —(CH 2 ) p PO 3 Q s , or R 8 and R 9 together with the nitrogen atom to which they are attached form a ring structure; and

R 16 , R 17 , R 18 and R 19 are independently selected from hydrogen or alkyl;

with the proviso that when R 4 is hydrogen, R 1 and/or R 2 is not hydrogen;

when R 4 is not hydrogen, R 1 and/or R 2 is hydrogen;

when R 4 and R 1 are both hydrogen, R 2 is not methyl; and

when R 4 and R 2 are both hydrogen, R 1 is not methyl.

2. A process according to claim 1 wherein the compound is a compound of formula (I), wherein:

R 1 is represented by hydrogen or C 1 alkyl;

R 2 is represented by hydrogen, —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —(CH 2 ) 2 OH, —(CH 2 ) 3 OH, —(CH 2 ) 6 OH, —CH 2 COOH, —CH 2 COONa, —CH 2 COOK, —(CH 2 ) 2 N(CH 3 ) 2 , —(CH 2 ) 2 N(CH 2 CH 2 ) 2 O, —(CH 2 ) 2 N(CH 2 CH 2 ) 2 S, —CH 2 (5-imidazole) or —(CH 2 ) 2 (5-imidazole);

R 3 is represented by hydrogen;

R 4 is represented by hydrogen, —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —(CH 2 ) 2 OH, —(CH 2 ) 3 OH, —(CH 2 ) 6 OH, —CH 2 COOH, —CH 2 COONa, —CH 2 COOK, —(CH 2 ) 2 N(CH 3 ) 2 , —(CH 2 ) 2 N(CH 2 CH 2 ) 2 O, —(CH 2 ) 2 N(CH 2 CH 2 ) 2 S, —CH 2 (5-imidazole) or —(CH 2 ) 2 (5-imidazole); and

R 5 is represented by hydrogen;

with the proviso that when R 4 is hydrogen, R 2 is not hydrogen;

when R 2 is hydrogen, R 4 is not hydrogen; and

when R 2 is hydrogen, R 1 is hydrogen and x is 0.

3. A process according to claim 2 wherein the compound is a compound of formula (I), wherein:

R 1 is represented by hydrogen or C 1 alkyl;

R 2 is represented by hydrogen, —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —(CH 2 ) 2 OH, —(CH 2 ) 3 OH, —(CH 2 ) 6 OH, —CH 2 COOH, —CH 2 COONa, —CH 2 COOK, —(CH 2 ) 2 N(CH 3 ) 2 , —(CH 2 ) 2 N(CH 2 CH 2 ) 2 O, —(CH 2 ) 2 N(CH 2 CH 2 ) 2 S, —CH 2 (5-imidazole) or —(CH 2 ) 2 (5-imidazole);

R 3 is represented by hydrogen;

R 4 is represented by hydrogen; and

R 5 is represented by hydrogen.

4. A process according to claim 2 wherein the compound is a compound of formula (I), wherein:

x is 0;

R 1 is represented by hydrogen;

R 2 is represented by hydrogen;

R 3 is represented by hydrogen;

R 4 is represented by hydrogen, —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —(CH 2 ) 2 OH, —(CH 2 ) 3 OH, —(CH 2 ) 6 OH, —CH 2 COOH, —CH 2 COONa, —CH 2 COOK, —(CH 2 ) 2 N(CH 3 ) 2 , —(CH 2 ) 2 N(CH 2 CH 2 ) 2 O, —(CH 2 ) 2 N(CH 2 CH 2 ) 2 S, —CH 2 (5-imidazole) or —(CH 2 ) 2 (5-imidazole); and

R 5 is represented by hydrogen.

5. A process according to claim 3 wherein the compound is a compound of formula (I), wherein:

R 1 is represented by hydrogen or C 1 alkyl;

R 2 is represented by —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —(CH 2 ) 2 OH, —(CH 2 ) 3 OH, —(CH 2 ) 6 OH, —CH 2 COOH or —(CH 2 ) 2 N(CH 3 ) 2 ;

R 3 is represented by hydrogen;

R 4 is represented by hydrogen; and

R 5 is represented by hydrogen.

6. A process according to claim 4 wherein the compound is a compound of formula (I), wherein:

R 1 is represented by hydrogen;

R 2 is represented by hydrogen;

R 3 is represented by hydrogen;

R 4 is represented by —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —(CH 2 ) 2 OH, —(CH 2 ) 3 OH or —(CH 2 ) 6 OH; and

R 5 is represented by hydrogen.

7. A process according to claim 2 wherein the compound is a compound of formula (I), wherein:

R 1 is represented by hydrogen or C 1 alkyl;

R 2 is represented by hydrogen, —CH 2 CH 3 , —CH 2 CH 2 CH 3 or —(CH 2 ) 2 N(CH 3 ) 2 ;

R 3 is represented by hydrogen;

R 4 is represented by hydrogen, —CH 2 CH 3 , —CH 2 CH 2 CH 3 or —(CH 2 ) 2 N(CH 3 ) 2 ; and

R 5 is represented by hydrogen;

with the proviso that when R 4 is hydrogen, R 2 is not hydrogen;

when R 2 is hydrogen, R 4 is not hydrogen; and

when R 2 is hydrogen, R 1 is hydrogen and x is 0.

8. A process according to claim 2 wherein the compound is selected from the group consisting of:

9. A process according to claim 2 wherein the compound is selected from the group consisting of: