Modelling in Membrane Separation of Bioactives

Abstract

Membrane based systems have become integral parts of the processing of bioactive compounds from the plant extract or fruit/vegetable juice. The technical feasibility of the process is generally established experimentally in small scale laboratory set ups. The results in the lab scale experimental data are generally used to scale up the process to the industrial level. To achieve this, a suitable model is needed. The major aspects of modelling the membrane-based systems are the prediction of the permeate flux and permeate concentration of the target species. These two parameters are related to the process throughput and quality of the product stream. The actual extract or juice is a complex fluid with an assortment of various components. Therefore, it is quite difficult to estimate the physico-chemical and transport properties of the extract/juice making the formulation of a physical model almost untenable. In this context, the popular models for tracing the behavior of the membrane-based systems are classified into three categories, namely, empirical, semi-empirical and transport phenomena based models from first principles. These three classes of the models are discussed in depth in this book chapter in relevance to the processing of the bioactive components. The assumptions, underlying physical principles, advantages, limitations and applicability of various models are discussed with great details. The models are also demonstrated with the practical case studies. It is envisaged that the presentation in this chapter would be of immense help to the design engineers to model and subsequent scaling up of the membrane processing of the production of bioactive components from the plant extract or the fruit/vegetable juices.