Kinetics Analysis of Supercritical Fluid Extraction for Natural Products

Based on the broken-intact cells model,a new simulation method of supercritical fluid extraction(SCFE) was presented.The initial and boundary conditions were obtained based on the process analysis and the necessary hypotheses.The SCFE processes of 9 materials(about 400 data) were simulated,the internal mass transfer coefficient of each material was obtained by taking the average relative deviation as the objective function,and the relationship between the grinding efficiency and the mean particle size for some substances were also given.The results of this work were contrasted with the conclusions in the relevant references,and they agree well.By simulating different materials,it could be concluded that a linear relationship exists between the grinding efficiency and the mean particle size.And the two stages of the SCFE process can be exactly distinguished.The effects of grinding efficiency and internal mass transfer coefficient on the extraction curve were discussed emphaticly.