CO2 solubility data are important for the efficient design and operation of the acid gas CO2 capture process using aqueous amine mixture. 2-(Diethylamino)ethanol (DEEA) solvent can be manufactured from renewable sources like agricultural products/residue, and 1,6-hexamethyldiamine (HMDA) solvents have higher absorption capacity as well as reaction rate with CO2 than conventional amine.based solvents. The equilibrium solubility of CO2 into aqueous binary mixture of DEEA and HMDA was investigated in the temperature range of 303.13-333.13 K and inlet CO2 partial pressure in the range of 10.133-20.265 kPa. Total concentration of aqueous amine mixtures in the range of 1.0-3.0 kmol/m3 and mole fraction of HMDA in total amine mixture in the range of 0.05-0.20 were taken in this work. CO2 absorption experiment was performed using semi-batch operated laboratory scale bubble column to measure equilibrium solubility of CO2 in amine mixture, and CO2 absorbed amount in saturated carbonated amine mixture was analyzed by precipitation-titration method using BaCl2. Maximum equilibrium CO2 solubility in aqueous amine mixture was observed at 0.2 of HMDA mole fraction in total amine mixture with 1.0 kmol/m3 total amine concentration. New solubility data of CO2 in DEEA+HMDA aqueous mixtures in the current study was compared with solubility data available in previous studies conducted by various researchers. The study shows that the new absorbent as a mixture of DEEA+HMDA is feasible for CO2 removal from coal-fired power plant stack gas streams.