Solubility of 3,5-Dinitrobenzoic Acid in Supercritical Carbon Dioxide with Cosolvent at Temperatures from (308 to 328) K and Pressures from (10.0 to 21.0) MPa

The solid solubility of 3,5-dinitrobenzoic acid in supercritical carbon dioxide with cosolvent, ethanol, ethyl acetate, n-propanol, and ethylene glycol was measured using a flow-type apparatus at temperatures from (308 to 328) K and in the pressure range of (10.0 to 21.0) MPa. The mole fraction of cosolvent was 0.015, 0.035, and 0.055, respectively. The experimental results showed that the equilibrium solubility of 3,5-dinitrobenzoic acid can be effectively enhanced in the presence of all cosolvents. A semiempirical model, the Sovova model, was modified by adding a function of temperature (7). The accuracy of the modified Sovova model was tested and verified by the solubility data of 17 kinds of solid compounds from the literature. In addition, the modified Sovova model was successfully used to correlate the experimental solubility data of 3,5-dinitrobenzoic acid in supercritical carbon dioxide with different cosolvents, and the average absolute relative deviation (AARD) ranged from (2.2 to 8.8) %.