Dynamic semi-batch supercritical fluid extraction model based on fundamentally thermodynamic equilibrium properties

A new dynamic extraction model was developed based on fundamentally thermodynamic equilibrium properties, such as solute solubility in the mobile phase and the solute distribution coefficient between the solid matrix and pseudo-liquid surface in the stationary phase for both supercritical fluid and ambient pressure extractions. In this model, the material balance of solute among the solid matrix, the pseudo-liquid surface and the mobile phase was satisfied at the given time step. The predictive mathematical form was obtained for proving the expression of many types of extraction curves. In addition, this model allows for adsorption isotherm equations instead of the solute distribution coefficient for expression of the extraction curves. In the future, this new model can be widely applied to the semi-batch extractions without kinetic parameters, such as mass transfer and diffusion coefficients, that were usually used in previous models.