Abstract

The aim of the present work is to validate a method based on electric conductivity measurements to monitor and analyze the kinetics of solute transfer at ambient temperature from agro-food solids (sugar beet particles) into a liquid phase (water). The first step consists of studying the correlation between two simultaneous measurements, that is, concentrations and electric conductivity of particles bed. A linear correlation could thus be revealed and it confirmed the correspondence of these two types of measurements. In fact, a close agreement is obtained between the normalized forms of the concentration and conductivity; the normalized parameters were then used to estimate and compare the kinetic parameters (e.g. k (min^-1) or D (m².min^-1)) of solute transfer. Close correspondence could be obtained between the kinetic parameters deduced from the normalized forms of the concentration and conductivity. Thus, using simple electric conductivity measurements may replace concentration ones which simplify the study of the kinetics of soluble matters extraction. Since electric conductivity measurements are quick, precise, and non-intrusive, this leads to gain in time and in number of repetitions when studying the kinetics of solvent solid-liquid extraction.

Key words: Kinetics solute transfer, Fick’s law, mass transfer, concentration, electric conductivity, diffusion coefficient.