Abstract:

Kinetic models for extraction process of volatile oil from traditional Chinese medicine are rarely studied at present; therefore, theoretical guidance to optimization of the process parameters is not enough.In this study, based on inner diffusion and gas film controlled diffusion, two new models were proposed by using Fick’s second law of diffusion.In order to evaluate the models, experiments for volatile oil extracted from Rhizoma atractylodis were carried out under different conditions.When the radii of particles were large, the process was controlled by inner diffusion and followed a first-order equation.When the radii were less than 0.090 mm, the process was controlled by gas film diffusion and the volume of volatile oil extracted was proportional to time.The simulations on extraction processes of other traditional Chinese medicines were also investigated.The data of experiment well accorded with the kinetic equation.The kinetic model was feasible to describe the actual extraction process and it provided a theoretical reference for the extraction process of volatile oil from traditional Chinese medicine.