Study of the Extraction Kinetics and Calculation of Effective Diffusivity and Mass Transfer Coefficient in Negative Pressure Cavitation Extraction of Paclitaxel from Taxus chinensis

In this study, the recovery efficiency of paclitaxel from Taxus chinensis was remarkably improved through negative pressure cavitation extraction. Most of the paclitaxel could be recovered from the biomass at a negative pressure of −260 mmHg with a one-time extraction in a short operating time (10–20 min). The pseudo-second-order model was suitable for the kinetic analysis, and the diffusion of paclitaxel in the biomass played a dominant role in the overall extraction rate according to the intraparticle diffusion model. As the negative pressure increased (0, −160, and −260 mmHg), the extraction rate constant (4.3325–5.9126 mL/mg·min), the effective diffusion coefficient (1.083 × 10−12 − 1.377 × 10−12 m2/s), and the mass transfer coefficient (1.428 × 10−7 − 2.371 × 10−7 m/s) increased.