Performance investigation and optimisation of electrodialysis regeneration for LiCl liquid desiccant cooling systems

In this paper, the regeneration performance of membrane electrodialysis (ED) with three different types of ion-exchange membrane pairs working with LiCl liquid desiccant solutions was first experimentally investigated. The membrane pair with the optimal performance for concentrating desiccant solutions was then identified and selected to quantitatively examine the effect of the operating parameters of ED on salt and water mass transfer, the concentration of the transferred solution and energy consumption of the ED stack using Taguchi method and analysis of variance. An optimisation was also performed to determine the optimal levels of the operating factors. The results showed the supplied current density significantly influenced the energy consumption of the ED stack but had a limited impact on the concentration of the transferred solution. Under the predicted optimal operating conditions, the energy consumption can be saved by 31.7% while the concentration of the transferred solution increased by 9.4% in comparison to the average values in the studied range. The main findings can be potentially used to guide optimal design and operation of ED regeneration for LiCl liquid desiccant cooling systems.