1Laboratory of Solar Energy and Medicinal Plants, Teacher's Training College, Cadi Ayyad University, B.P. 2400, Marrakesh, Morocco
2Laboratory of Physics of Materials and Systems Modelling (LP2MS), URAC08, My Ismail University, Faculty of Science, B.P. 11201, Zitoune Meknes, Morocco
Online published on 21 November, 2017.
Water desorption isotherms of Zygophyllum gaetulum were investigated at three temperatures 30, 40 and 50°C, by the dynamic gravimetric method. Experimental data are used to determine the best models for predicting the desorption equilibrium moisture content of Z. gaetulum for known values of temperature and water activity. The second part of this study deals with the drying kinetics of Zygophyllum gaetulum in a convective solar drying. The experimental results are used to determine the characteristic drying curve. Moisture transfer from Z.gaetulum was described by applying the Fick's diffusion model. The effective diffusivity values changed from 7.89 10−11 to 2.42 10−10 m2.s−1 within the given temperature range. An Arrhenius relation with an activation energy value of 56.72 kJ.mol−1 expressed the effect of temperature on the diffusivity.
Desorption isotherms, Drying kinetics, Effective diffusivity, Forced convection, Zygophyllum gaetulum
