To determine the possibility of improvement of the process of CO2 removal by absorption with alkanolamines, densities, viscosities, and refractive indices of four aqueous alkanolamine solutions (water + monoisopropanolamine (MIPA), diisopropanolamine (DIPA), triisopropanolamine (TIPA), or diethanolamine (DEA)) were measured in the temperature range (298.15 to 343.15) K and at atmospheric pressure. Due to the corrosive effect of increased concentration of alkanolamine solutions, the mass fractions of alkanolamines were selected as w = 0.05, 0.1, 0.15, 0.20, and 0.25. The measured data were regressed with polynomial equations. Obtained results provide necessary data for industrial equipment design and process optimization regarding greenhouse gases (GHG), but also it is a foundation for further investigation of the potential replacement of usually used monoethanolamine with other mixtures of alkanolamine solutions presented within this work.