Improved reverse electro-dialysis using membranes with integrated spacers

Reverse Electro-Dialysis, RED, utilises the energy of mixing between two solutions of different salinity by allowing ionic current to pass through the membranes and the two solutions such that cations are transport to the cathode and anions to the anode. [1-4] The ionic current is converted to electronic current by red-ox reactions at the cathode and the anode. The membranesapplied in this process are ionic selective, traditionally of uniform thickness and separated by a non-conductive spacer [5, 6]. Traditionally, non-conductive spacers have been deployed as eddy promoters and membrane spacers in salinity difference power extraction systems, such as Pressure Retarded Osmosis (PRO) and Reverse Electro-Dialysis (RED).