Energy recovery from the flow-electrode capacitive deionization

The energy consumed during the desalination process in a flow-electrode capacitive deionization (FCDI) is recovered by a two-chamber device, where the adsorbed electrodes are discharged with constant current. When single constant discharge current is applied, the maximum energy of 36.3 J can be obtained with 0.50 mA/cm(2) discharge current density. Much more energy is recovered by applying successive discharge currents. With additional conductive agent carbon nanotubes in the suspend carbon electrodes, the ratio was further enhanced by 60%. Increased salt concentration of the electrolyte could decrease the energy consumption and improve the energy recovery. The energy recovery ratio was promoted to 9.4% when the salt concentration of the electrolyte increased to 9.60 gL(-1).