Considering the different point of views of solid-liquid extraction kinetic modeling and diffusivity estimation, it is necessary a
unified model that represents the process with a theoretical basis. A
unified model must be deduced from fundamental principles of
mass transfer and thermodynamics, and it must have the property
of predict the phenomenon at different conditions than those used
to estimate the mass transfer properties. Therefore, in this paper a
deep analysis of mass transfer equation governing the process dynamic is presented. It was declared as dynamic, because the mass
transfer equations (local or space-averaged) represent the solid-
liquid extraction kinetics in terms of driven forces. The analysis
was performed for both, local and spaceaveraged equations and
included dimensionless analysis, analytical solution and experimental validation. Obtained analytical solutions are continuous and
analytical maps that relate extractable solutes mass fraction in both
phases (extract and underflow) with the process time. These maps
were used for the extractable solute effective diffusivity estimation
during vanilla solid-liquid extraction and for the prediction of
experimental extraction kinetics in the same system at different
product/solvent ratios.