Correlations for the physical and thermodynamic properties of liquid mixtures in post-combustion CO2 capture processes

To reduce the increase of CO 2 concentration in the atmosphere, absorption of CO 2 with a chemical solvent is the most well-established technology. The primary objective is to evaluate the density and viscosity of ternary solutions containing Piperazine (PZ), 2-Amino-2-methyl-1-propanol (AMP), and water (H₂O) and to analyze correlations for predicting their physical properties. The density of PZ and AMP solutions were measured with a DMA 4500 density meter across a range of mass fractions and a temperature range between 303 K and 353 K. Viscosity measurements were conducted for the same samples using an MCR 101 rheometer. The density and viscosity data were fitted to correlation models. Average absolute relative deviations (AARD) between laboratory data and correlation models were calculated for different correlations. Two density correlations were proposed: a polynomial function and a power function. The polynomial model showed the best fit with an AARD of 0.0034% while the AARD of the power model was 0.066%. Compared with literature, the polynomial model in this study shows a significantly lower AARD. In viscosity modeling, the AARD in the Tait model, logarithmic model and empirical model were calculated to 0.16%, 4.5% and 0.41% respectively. This shows the superiority of the Tait model. This work contributes to improving models to predict density and viscosity in mixtures of aqueous AMP and PZ. These models improve the predictions of density and viscosity in process simulation tools.