Densities of CO ₂ -Loaded and Unloaded 3-Amino-1-propanol Aqueous Solutions and Their Blends with 2-Amino-2-methyl-1-propanol at High Pressures

Carbon capture and storage and carbon capture and utilization are key technologies to reduce CO₂ emissions by capturing and storing (or converting) CO₂. In this context, amine-based aqueous solutions play a key role in these processes, especially because of their efficiency in chemically binding CO₂. However, some physical properties under high pressure and temperature systems remain poorly reported in physical chemical databases. This work presents experimental data on the density of aqueous amine solutions of 3-amino-1-propanol (AP) when they are CO₂-loaded and unloaded and its blends with 2-amino-2-methyl-1-propanol (AMP) (unloaded) under high-pressure conditions (up to 100 MPa) and at a wide temperature range (293.15-393.15 K). Density measurements were performed using a vibrating tube densimeter (Anton Paar DMA HPM), and data were correlated with a modified Tammann-Tait equation, resulting in excellent correlation. These results served as the support information for estimation of molar volumes and isothermal expansion coefficients. Overall, density increased with pressure and decreased with temperature for all amine solutions tested. At low AP concentrations, a local minimum was observed for the isothermal expansion coefficient, which is probably attributed to anomalous water compressibility. Additionally, the CO₂ loading led to an increase in density and a decrease in thermal expansion coefficients. Finally, elemental analysis revealed a possible corrosion, especially in blends of AP + AMP and CO₂-loaded solutions, providing valuable insights for material selection and process design.