Modeling of mass transfer during continuous drying of Urtica urens leaves

Urtica urens is one of the main medicinal plants used in the pharmaceutical industry and traditional medicine. It is necessary to know the process of drying and storage of this product. This work is a contribution to the understanding of the mass transfer mechanisms by modeling the drying process of the Urtica urens leaves. The isothermal diffusive model is based on solving the one-dimensional Fick equation. Moreover, an algorithm of minimization compiled by MATLAB is used in this study to get the optimal parameters of the model. The results showed a reasonably good agreement between the values predicted from the model and the experimental observations. This confrontation has helped to identify the diffusion coefficient and the activation energy of the Urtica urens leaves. The effective diffusivity values changed from 4.94 10-11 to 9.66 10-11 within the given temperature range, and the activation energy was found to be 29.34 . In fact, the proposed model accurately describes, on a macroscopic scale, mass transfer processes in the product