Modélisation du transfert de matière lors d’une extraction solide - liquide

Abstract

In this paper, a theoretical study which deals with modeling of mass transfer phenomenon occurring during essential oil extraction from solids of vegetal origin, namely coriander grains (Coriander sativum L) is presented. The objective is twofold: the first one is to understand the mechanisms involved during molecular diffusion through solids of vegetal origin based on many models developed in the literature. The second objective is to propose a model which represents kinetics of extraction by modification of some hypothesis retained in bibliographical models. The proposed model is a combination of two terms: the first one represents molecular diffusion of solute present in open cells located near particle's surface (predominant at low extraction times) and the second one represents generation of solute according to a first order reaction to simulate the additional resistance due to cell's break up (predominant at high extraction times). Comparison between simulations and experimental results taken from bibliographical references has shown a good agreement for large range of extraction times.