KINETIC MODELING OF SUBLIMATION AND VAPORIZATION IN LOW-TEMPERATURE DEHYDRATION PROCESSES

In this work a kinetic analysis has been carried out under two low-tem perature dehydration techniques: freeze-drying and controlled low-temp erature vacuum dehydration (CLTVD). The CLTVD process is described as a uniformly retreating ice front (URIF) and a sublimation-vaporization model which considers an additional mechanism for the diffusion of li quid water. A comparative analysis on the basis of mass transfer coeff icients according to the proposed model is made. The kinetic parameter s obtained were compared and studied in order to deduce conclusions ab out the convenience of both techniques and the possibilities of each m odel to describe the process kinetically.