The density of (30 mass % potassium carbonate + 3 mass % sarcosine) and (30 mass % K2CO3 + 3 mass % pipecolic acid) were measured for temperature ranging from (303 to 353) K. The experimental data are presented with an aqueous solution of 30 mass % K2CO3 . The solubility of the aqueous blended solution was measured at (353, 373, and 393) K over CO2 partial pressure ranging from (0.1 to 1500) kPa. The results are shown with the solubility of CO2 in 30 mass % K2CO3 . Due to the fact that the amino acid has acidic character, the CO2 solubility of aqueous blended solutions is slightly lower than that of the solution of 30 mass % K2CO3.