Improving energy recovery in CDI systems

One of the latest methods for desalinating water is the so-called Capacitive De-Ionization (CDI). The technology is based on carbon electrodes that are capable of adsorbing ionic components from water. The aim of this paper is to present a water desalination system in which a dc/dc converter is used to efficiently recover part of the energy involved. The CDI process and the characteristics of the energy recovery system are described. An up/down converter is studied and modeled in order to determine the critical design parameters to fulfill these special characteristics. The experimental results obtained show an important capability for the energy recovery.