Dehydration and dielectric permittivity measurements of a porous, inorganic material (13X zeolite) heated with microwave power

The microwave drying of 13X zeolite is experimentally studied by continuously measuring the permittivity of a sample zeolite material during given microwave drying cycles. The results are interpreted in light of the dielectric theory of heterogeneous mixtures, making it possible to distinguish the water vapor in circulation within the zeolite structure from the water absorbed on the solid material. The results agree with previous data, showing that the adsorbed water molecules are much less mobile than the free water molecules. Time constants involved with the desorption and transport processes of water are obtained under microwave power heating conditions