Volumetric properties of CO ₂ -loaded and unloaded 3-amino-1- propanol/1-amino-2-propanol/3-dimethylamino-1-propanol + N, N-dimethylacetamide binary mixture at (288.15 to 323.15) K and 101 kPa

In this work, the densities of CO2-loaded and unloaded alkanolamine (1) + N, N-dimethylacetamide (DMAC) (2) mixtures were determined at temperature of (288.15 to 323.15) K and 101 kPa. The alkanolamines were primary amines, 3-amino-1-propanol (3A1P) and 1-amino-2-propanol (1A2P), and tertiary amine, 3-dimethylamino-1-propanol (3DMA1P). There CO2-unloaded 3A1P/1A2P/3DMA1P + DMAC binary systems with the whole concentration and two CO2-loaded 3A1P/1A2P + DMAC systems with alkanolamine mass fraction of (0.2, 0.3 and 0.4) were investigated. Based on the density values of CO2-unloaded binary systems, the thermal expansion coefficient (αp), excess molar volume (VmE), and apparent molar volume (Vφ,i) were calculated and discussed in terms of intermolecular interactions and spatial structure. The VmE values were positive under the studied conditions and increased with the temperature, and the maximum followed the decreasing order of 1A2P + DMAC > 3DMA1P + DMAC > 3A1P + DMAC. Additionally, the VmE data were well fitted with the Redlich-Kister equation with a small standard deviation (σ ≤ 0.024). For the CO2-loaded systems, the density values were correlated with temperature and concentration using different empirical equations, and the average relative deviations (ARD%) were less than 0.299%.