Carbon capture solvents and methods for using such solvents

1. A solvent for recovering carbon dioxide from a gaseous mixture, consisting of:

(a) 30 to 40 wt % of an alkanolamine, wherein the alkanolamine is either N-methyldiethanolamine (MDEA) or 2-amino-2-methyl-1-propanol (AMP),

(b) 10 to 18 wt % of a reactive amine, wherein reactive amine is N-aminoethylpiperazine (AEP),

(c) a carbonate buffer, and

(d) 15 to 20 wt % of a glycol,

wherein the solvent contains less than about 45% by weight of water and is in a single liquid phase.

2. The solvent as claimed in claim 1 , wherein the glycol is polyethylene glycol.

3. The solvent as claimed in claim 1 , the solvent is less than about 30% by weight of water.

4. The solvent as claimed in claim 1 , wherein the carbonate buffer is a potassium carbonate buffer.

5. The solvent as claimed in claim 1 , wherein the reactive amine is between 11% and 15 wt % of the solvent.

6. The solvent as claimed in claim 1 , wherein the carbonate buffer buffers the solution to a pH of between about 12 and 14 in the absence of CO2.

7. The solvent as claimed in claim 1 , wherein the glycol is monoethylene glycol.

8. The solvent as claimed in claim 1 , wherein the glycol is diethylene glycol (DEG).

9. A solvent for recovering carbon dioxide from a gaseous mixture, consisting of:

(a) 20 to 40 wt % of an alkanolamine,

(b) 10 to 20 wt % of a reactive amine,

(c) carbonate buffer, (d) 10 to 20 wt % of a glycol, and (e) less than 60 wt % water, wherein the solvent is in a single liquid phase, wherein the alkanolamine

is N-methyldiethanolamine (MDEA) and the reactive amine is N-aminoethylpiperazine (AEP).

10. The solvent as claimed in claim 9 , wherein the glycol is ethylene glycol.