Densities and Viscosities of Binary and Ternary Solutions of Triethylenetetramine, 2-Amino-2-methyl-1-propanol, and Water for Carbon Dioxide Capture

The densities and viscosities of three solutions, namely, two binary solutions [triethylenetetramine (TETA) + H2O and TETA + 2-amino-2-methyl-1-propanol (AMP)] and one ternary solution (TETA + AMP + H2O) were measured at atmospheric pressure and in the temperature range of 303.15 to 343.15 K. Their viscometric and volumetric characteristics, such as the excess molar volume (VE), partial molar volume (V¯ i), excess partial molar volume (V¯ iE), partial molar volume at infinite dilution (V¯ i∞), excess partial molar volume at infinite dilution (V¯ iE,∞), apparent molar volume (Vφ.i), viscosity deviation (δη), molar Gibbs free energy (δG), molar entropy (δS), and molar enthalpy (δH), were calculated to determine the viscous flows of the solutions, and they could also explain the empirical results theoretically. The degrees of the decrease in viscosities and densities of the solutions were different. The variations in the properties were also analyzed through their intermolecular interactions and molecular structures. Additionally, δη and VE were obtained by the Redlich-Kister model, for the binary solutions, and the Cibulka model, for the ternary solution. With the given standard deviations, σ ≤ 3.55, for the binary solutions, and σ = 3.98, for the ternary solution, the viscosity data were parameterized by the Eyring-non-random two-liquid model. The obtained thermodynamic properties were reliable and could be employed in the design and optimization of a CO2-capture process, utilizing the studied solutions.