Electrodiffusion of ions in ion exchange membranes: Finite element simulations and experiments

Electrodiffusion of ions in both cation (CEM) and anion exchange membranes (AEM) has been studied with theoretical calculations experimental studies. Calculations are based on the Finite Element Method (FEM) using COMSOL Multiphysics® software. Nernst-Planck equations solved multi-ionic systems where no closed form solutions available. Simulations compared laboratory-scale experiments terms current efficiency membrane selectivity. revealed unexpected features transport, due to coupling ionic fluxes when local electroneutrality condition is assumed. Transport weak electrolytes showed importance involving equilibria along concentration profiles membranes, compelling consider constituents. The advantage simulations ease find potential across entire system, split diffusion migration contributions, showing their even absence electric current.