Liquid Density of Aqueous Blended Alkanolamines and N-Methylpyrrolidone as a Function of Concentration and Temperature

Experimental values of the liquid density have been determined for ternary systems formed by aqueous mixtures of diethanolamine (DEA) + methyldiethanolamine (MDEA), DEA + 2-amino-2-methy-l-propanol (AMP), DEA + 2-piperidineethanol (2PE), DEA + N -methylpyrrolidone (NMP), MDEA + AMP, MDEA + 2PE, MDEA + NMP, and NMP + AMP. The data were obtained at (313.15, 323.15, and 333.15) K, the total concentration of the blended solvents studied was in the range 30−60 mass %, and for each concentration at least seven points were obtained with different proportions of each solvent. The estimated accuracy of the data is ±0.0004 g·cm - 3 . From the density data, molar excess volumes were derived, which were correlated using the Redlich−Kister equation; the final expression includes the functionality of both concentration and temperature.