Estimation of Solubility of Benzoic Acid in Supercritical Carbon Dioxide with and without Cosolvent

فاقد چكيده فارسي

Supercritical fluid extraction is one of the effective methods in separation and purification of pharmaceuticals. In this study, the solubility of benzoic acid in supercritical carbon dioxide with and without cosolvent was investigated by the Peng-Robinson equation of state combined with the Wong-Sandler mixing rule. The van Laar model was used to express the excess Gibbs energy. Since the experimental critical point of benzoic acid is not available due to its temperature sensitivity, the critical point was estimated by different group contribution methods. The most accurate critical point and acentric factor were determined with the help of experimental vapor pressure. Then, the critical point and acentric factor were applied to the Peng-Robinson equation to calculate the solubility of benzoic acid in supercritical carbon dioxide. The AARDs of 3.21% and 3.76% were obtained for estimating the solubility of benzoic acid in the supercritical CO2 without and with methanol as a cosolvent, respectively.