Carbon capture solvents having alcohols and amines and methods for using such solvents

Abstract

Methods and compositions useful, for example, for physical solvent carbon capture. The solvents may include an aqueous mixture of 2-amino-2-methylproponol, 2-piperazine-1-ethylamine, diethylenetriamine, 2-methylamino-2-methyl-1-propanol, and potassium carbonate or potassium carbonate buffer salt. The solvent may also contain less than about 75% by weight of dissolving medium (i.e., water) and may have a single liquid phase. The solvents and methods have favourable regeneration energies, chemical stability, vapour pressure, total heat consumption, net cyclic capacity, and reaction kinetics.

1 . A aqueous aqueous solvent comprising:
 2-methylamino-2-methyl-1-propanol and 2-amino-2-methylpropanol combined having a vapor pressure less than 0.1 kPa at 25° C.;   2-piperazine-1-ethylamine and diethylenetriamine combined having a vapor pressure less than 0.009 kPa at 25° C.; and,   a carbonate buffer;   wherein the aqueous solvent has a vapor pressure less than 1.85 kPa at 25° C.   
     
     
         2 . The aqueous solvent of  claim 1 , wherein the aqueous solvent results in no foaming upon contact with CO 2 . 
     
     
         3 . The aqueous solvent of  claim 1 , wherein the aqueous solvent results in emission of aerosols less than 32 mg/Nm 3  upon contact with CO 2 . 
     
     
         4 . The aqueous solvent of  claim 1 , wherein the aqueous solvent results in emission of aerosols less than 28 mg/Nm 3  upon contact with CO 2 . 
     
     
         5 . The aqueous solvent of  claim 1 , wherein the aqueous solvent results in emission of aerosols less than 16.4 mg/Nm 3  upon contact with CO 2 . 
     
     
         6 . The aqueous solvent of  claim 1 , wherein the aqueous solvent results in emission of aerosols less than 5.6 mg/Nm 3  upon contact with CO 2 . 
     
     
         7 . The aqueous solvent of  claim 1 , wherein the amino hindered alcohol is 2-amino-2-methylproponol and the aqueous solvent results in emission of aerosols less than 16.4 mg/Nm 3  upon contact with CO 2 . 
     
     
         8 . The aqueous solvent of  claim 1 , wherein the temperature at which the aqueous solvent contacts CO 2  is: from 30 to 50° C.; or, from 35 to 45° C.; or, from 39 to 43° C.; or, from 39.94 to 42.2° C. 
     
     
         9 . The aqueous solvent of  claim 1 , wherein the pressure at which the aqueous solvent contacts CO 2  is: from 34474 to 103421 Pa (5 to 15 psig); or, from 62053 to 75842 Pa (9 to 11 psig); or, 68948 Pa (10 psig). 
     
     
         10 . The aqueous solvent of  claim 1 , wherein the size of the aerosols formed upon contact of the aqueous solvent with CO 2  is: from 0.1 to 15 mm; or, from 0.2 to 13 mm; or, from 0.43 to 11 mm. 
     
     
         11 . The aqueous solvent of  claim 1 , wherein 2-methylamino-2-methyl-1-propanol is present from 0.8 wt % to 5 wt %, wherein 2-amino-2-methylpropanol is present from 10 wt % to 32 wt %; 2-piperazine-1-ethylamine is present from 10 wt % to 35 wt %; and diethylenetriamine is present from 0.1 wt % to 4 wt %. 
     
     
         12 . The aqueous solvent of  claim 1 , wherein the carbonate buffer is selected from the group consisting of sodium carbonate, potassium carbonate, calcium carbonate, ammonium carbonate, magnesium carbonate, and a combination thereof. 
     
     
         13 . A aqueous aqueous solvent comprising:
 2-methylamino-2-methyl-1-propanol and 2-amino-2-methylpropanol combined having a vapor pressure less than 0.1 kPa at 25° C., wherein the 2-methylamino-2-methyl-1-propanol is present from 0.8 wt % to 5 wt %;   2-piperazine-l-ethylamine and diethylenetriamine combined having a vapor pressure less than 0.009 kPa at 25° C., wherein the diethylenetriamine is present from 0.1 wt % to 4 wt %.; and,   a carbonate buffer;   wherein the aqueous solvent has a vapor pressure less than 1.85 kPa at 25° C.   
     
     
         14 . The aqueous solvent of  claim 13 , wherein the 2-amino-2-methylpropanol is present from 10 wt % to 32 wt%; and the 2-piperazine-1-ethylamine is present from 10 wt % to 35 wt %. 
     
     
         15 . The aqueous solvent of  claim 13 , wherein the carbonate buffer is selected from the group consisting of sodium carbonate, potassium carbonate, calcium carbonate, ammonium carbonate, magnesium carbonate, and a combination thereof.