Solubility of the silver nitrate in supercritical carbon dioxide with ethanol and ethylene glycol as double cosolvents: Experimental determination and correlation

Solubility of the silver nitrate in the supercritical carbon dioxide containing ethanol and ethylene glycol as double cosolvents was measured under certain pressure and temperature range (10-25 MPa, 323.15-333.15 K). The impact of the pressure and temperature on the solubility was also investigated. Based on the experiment data, a correlation model concerning solid's solubility in supercritical fluids was established by combining the solubility parameter with the thermodynamic equation when a binary interaction parameter and a mixed solvent solubility parameter were defined. Experiments show the solubility of AgNO₃ increases with the pressure at a certain temperature. However, the influence of temperature is related to a pressure defined as the turnover pressure (12.3 MPa). When the pressure is higher (or lower) than this turnover pressure, silver nitrate's solubility shows increasing (or decreasing) trend as the temperature rises. Satisfactory accuracy of our presented model was revealed by comparing experimental data with calculated results.