Physicochemical Characteristics for CO₂-Loaded Aqueous Bis(3-aminopropyl)amine and Its Mixture with 2-Amino-2-methyl-1-propanol

Removal of CO2 from industrial exhaust gas is vital and is commonly achieved by using chemical absorption with newly formulated solvents. The density and viscosity of carbonated solutions are critical physicochemical properties for selecting an efficient solvent in the CO2 absorption processes. In this work, aqueous bis(3-aminopropyl)amine (APA) and its mixture with 2-amino-2-methyl-1-propanol (AMP) are considered to be promising absorbents for the CO2 capture process. New experimental density and viscosity data for CO2-loaded APA and APA + AMP mixtures were determined over a temperature range of 303.25–328.25 K and different CO2 concentrations pertaining to the gas absorption condition. The density and viscosity of the CO2-loaded APA and APA-AMP solvent systems were correlated using thermodynamics models, with parameters determined for different aqueous carbonated solvent compositions across the studied temperature range. The modeling results show that the percentage average absolute deviations (% AADs) between the experimental and model results of density were 0.03 for the ternary system (APA + H2O + CO2) and 0.13 for the quaternary system (APA + AMP + H2O + CO2). The % AADs between experimental and model viscosity data are 0.88 and 2.97, respectively. The obtained results provide valuable insights into the development of amine-based solvents for efficient CO2 capture applications.