Density and Viscosity of Aqueous (Ammonia + Carbon Dioxide) Solutions at Atmospheric Pressure and Temperatures between 278.15 and 318.15 K

摘要

The density and the viscosity of aqueous (NH_(3) + CO_(2)) solutions have been measured at atmospheric pressure over a temperature range of 278 to 318 K and apparent concentrations of solute between 4 and 10 mol_(NH_(3)) kg H_(2)O) –1) for NH_(3) and between 1 and 5.2 mol_(CO_(2)) kg H_(2)O) –1) for CO_(2). Solute loss from the aqueous solution associated with the high equilibrium partial pressure of NH_(3) and of CO_(2) has been limited by devices and protocols developed ad-hoc for sample preparation and density and viscosity measurement. Solid or vapor formation out of the initial liquid mixture has been avoided by means of a thermodynamic model-driven design of experiments. The experimental values gathered in this work have been used to obtain empirical models of density and viscosity, as a function of the apparent concentration of solutes, that is, NH_(3) and CO_(2), and temperature, that are able to reproduce the experimental values in all cases with deviations below 1.1% for density and below 9.4% for viscosity. While it is the first time that, to our knowledge, experimental viscosity data of aqueous ammonia solutions loaded with CO_(2) are added to the literature, the density model developed in this work is also able to reproduce experimental density data from literature with deviations below 1.5%, even outside the boundaries of the experimental conditions considered in this work.