Density of unloaded and CO 2 -loaded aqueous solutions of piperazine and 2-amino-2-methyl-1-propanol and their mixtures from 293.15 to 333.15 K.

The densities of unloaded and partially carbonated piperazine (PZ) and 2-amino-2-methyl-1-propanol (AMP) aqueous solutions and their blends were measured at temperatures of 293.15 to 333.15 K. The results of these measurements were used to calculate excess molar volumes assuming that the volume of carbon dioxide dissolved in the solutions was zero. The excess molar volumes were correlated as a function of the CO2mole fraction using the Redlich–Kister equation. The results of the actual density are discussed in comparison with the case if no volume expansion occurs during the loading of the solutions. The no-volume-expansion model can be used to give an initial estimate of the density, while the Redlich–Kister equation is suitable for a precise density estimation. It must be noted that the no-volume-expansion model does not require any parameters except the density of the unloaded solution, unlike the Redlich–Kister equation, whose coefficients are regressed from experimental data. [ABSTRACT FROM AUTHOR]