Physical Properties\nof Aqueous Piperazine + Glycine\nSolutions as Blended Absorbent for Carbon Dioxide Capture

The density, vapor pressure, and dynamic viscosity of\npiperazine\n(PZ) + glycine solutions were measured for various equimolal concentration\nranges (<i>m</i><sub>PZ and Gly</sub> = (0.501–3.009))\nat 0.1 MPa pressure and temperature ranging from 303.15 to 353.15\nK. The diffusion coefficient, thermal expansion coefficient, and viscosity\nactivation energy values were computed based on the measured data\nof density and dynamic viscosity. These physical properties data would\nbe of great significance for designing post-combustion CO<sub>2</sub> capture systems utilizing PZ-based absorbent blended with aqueous\namino acids solutions. The investigation of data on physical properties\nrevealed that as the molality of the PZ-glycine solution increases,\nboth the density and viscosity increase, whereas the vapor pressure\ndecreases. Moreover, as the temperature rises, the density and dynamic\nviscosity decrease, while the vapor pressure increases.