Modelling of electrosorption of ions in a flow cell

Abstract

Salt removal through electrosorption is an electric field mediated adsorption phenomena that is based on the applied potential, nature and area of the electrode surface and concentration of salt in the electrolyte. Understanding of the phenomena can help establish the limits of adsorption (salt removal), the kinetics and its efficiency. In this thesis, we investigate the change in the effluent salt concentration with time and its dependence on operation parameters, through modelling a electrosorption process in a flow cell. We model the salt removal and electrosorption kinetics, using the Gouy-Chapman-Stern (GCS) layer model and a modified donnan (mD) model, with applied potential, flow rate in simple electrode cell. The proposed models were solved using finite element based simulation package (COMSOL). It is seen that the results compare favourably with experimental data (provided by Unilever) for the change of the effluent salt concentration in time.