An absorbent composition, comprising: an aqueous solvent comprising water and an amine mixture of at least a first sterically hindered amine and a second sterically hindered amine; and an organic co-solvent selected from the group consisting of sulfones, sulfone derivatives, and sulfoxides, - wherein said absorbent composition comprises from 75 wt. % to 92 wt. % said aqueous solvent, and from 8 wt. % to 25 wt. % said organic co-solvent, with the wt. % being based on the total weight of the absorbent composition, - wherein said amine mixture is an amination product of a polydispersed polyethylene glycol mixture having an average molecular weight that is in the range of from 180 to 1000 and t-butylamine, and - wherein said PEG mixture comprises polyethylene glycols of the formula HOCH2(CH2OCH2)nCH2OH, wherein n is an integer selected from values in the range of from 1 to 24, and - wherein said PEG mixture includes two or more different PEG compounds having the aforementioned formula, wherein n is an integer selected from values in the range of from 1 to 24, and - wherein the amination reaction product has been prepared using an amination catalyst comprising: from 40 to 90 wt. % nickel; from 4 to 40 wt. % copper; and from 1 to 50 wt. % of either zirconium or chromium, or a combination of both zirconium and chromium, and - wherein said first sterically hindered amine is selected from the group of amine compounds of the formula: (CH 3) 3 CNH(CH 2 CH 2 O) x CH 2 CH 2 NHC(CH 3) 3, wherein x is an integer in the range of from 3 to 14; and - wherein said second sterically hindered amine is selected from the group of amine compounds having the following formula: (CH 3) 3 CNH(CH 2 CH 2 O) x CH 2 CH 2 OH, wherein x is an integer in the range of from 3 to 14, and - wherein said weight ratio of said first sterically hindered amine to said second sterically hindered amine is in the range of from 3:1 to 6:1. an aqueous solvent comprising water and an amine mixture of at least a first sterically hindered amine and a second sterically hindered amine; and an organic co-solvent selected from the group consisting of sulfones, sulfone derivatives, and sulfoxides, - wherein said absorbent composition comprises from 75 wt. % to 92 wt. % said aqueous solvent, and from 8 wt. % to 25 wt. % said organic co-solvent, with the wt. % being based on the total weight of the absorbent composition, - wherein said amine mixture is an amination product of a polydispersed polyethylene glycol mixture having an average molecular weight that is in the range of from 180 to 1000 and t-butylamine, and - wherein said PEG mixture comprises polyethylene glycols of the formula HOCH2(CH2OCH2)nCH2OH, wherein n is an integer selected from values in the range of from 1 to 24, and - wherein said PEG mixture includes two or more different PEG compounds having the aforementioned formula, wherein n is an integer selected from values in the range of from 1 to 24, and - wherein the amination reaction product has been prepared using an amination catalyst comprising: from 40 to 90 wt. % nickel; from 4 to 40 wt. % copper; and from 1 to 50 wt. % of either zirconium or chromium, or a combination of both zirconium and chromium, and - wherein said first sterically hindered amine is selected from the group of amine compounds of the formula: (CH 3) 3 CNH(CH 2 CH 2 O) x CH 2 CH 2 NHC(CH 3) 3, wherein x is an integer in the range of from 3 to 14; and - wherein said second sterically hindered amine is selected from the group of amine compounds having the following formula: (CH 3) 3 CNH(CH 2 CH 2 O) x CH 2 CH 2 OH, wherein x is an integer in the range of from 3 to 14, and - wherein said weight ratio of said first sterically hindered amine to said second sterically hindered amine is in the range of from 3:1 to 6:1. - wherein said absorbent composition comprises from 75 wt. % to 92 wt. % said aqueous solvent, and from 8 wt. % to 25 wt. % said organic co-solvent, with the wt. % being based on the total weight of the absorbent composition, - wherein said amine mixture is an amination product of a polydispersed polyethylene glycol mixture having an average molecular weight that is in the range of from 180 to 1000 and t-butylamine, and - wherein said PEG mixture comprises polyethylene glycols of the formula HOCH2(CH2OCH2)nCH2OH, wherein n is an integer selected from values in the range of from 1 to 24, and - wherein said PEG mixture includes two or more different PEG compounds having the aforementioned formula, wherein n is an integer selected from values in the range of from 1 to 24, and - wherein the amination reaction product has been prepared using an amination catalyst comprising: from 40 to 90 wt. % nickel; from 4 to 40 wt. % copper; and from 1 to 50 wt. % of either zirconium or chromium, or a combination of both zirconium and chromium, and - wherein said first sterically hindered amine is selected from the group of amine compounds of the formula: (CH 3) 3 CNH(CH 2 CH 2 O) x CH 2 CH 2 NHC(CH 3) 3, wherein x is an integer in the range of from 3 to 14; and - wherein said second sterically hindered amine is selected from the group of amine compounds having the following formula: (CH 3) 3 CNH(CH 2 CH 2 O) x CH 2 CH 2 OH, wherein x is an integer in the range of from 3 to 14, and - wherein said weight ratio of said first sterically hindered amine to said second sterically hindered amine is in the range of from 3:1 to 6:1.