Voltage control for membrane capacitive de-ionization cell for higher energy efficiency in salt removal

Abstract

Membrane Capacitive DeIonization (MCDI) cells have proven to be advantageous in water desalination and ions removal. Therefore, the time has come to introduce an alternative water purification technique to reduce the global water shortage. MCDI is known to be environmentally friendly, energy efficient and economical. Besides its reduced energy footprint, recent applications underline the regenerated energy during the desorption phase, which makes the MCDI as a potential cleaner energy source. Thus, a large number of scientific publications addressing problems and enhancing the performance of an MCDI have been published. In this paper, we have developed a simple and inexpensive method to control the adsorption voltage of the cells. So, the ion adsorption/desorption mechanisms of the MCDI will be controlled by a variable charging voltage applied to the cell.The entire response of controlled MCDI integrated model was created and he simulated results were compared with the experimental ones in order to validate the results. Accordingly, the controller parameters were tuned using the genetic algorithm optimization technique, based on the integral time absolute error criterion. Furthermore, the experimental results reveal that the control of the cell had increased the salt retention by 50%, the quantity of removed salt by the energy unit was improved by 10%, and the cell energy ratio from 28% to 32%.