Modification of Polymeric Membrane for Energy Generation through Salinity Gradient: A Short Review

Salinity gradient energy (SGE) refers to the energy created from the difference in salt concentration between two streams. There are three types of SGE namely, pressure retarded osmosis (PRO), reverse electrodialysis (RED), and capacitive mixing (CapMix). All these technologies require membrane for the system to be operational. In this short review, the membranes modifications for each principle and its strategies in improving the performance of their membranes are presented. The technological progress of SGE is currently constrained by its ability in generating low power density. Thus, further modifications on every aspect of the systems is needed to overcome this bottleneck. This review focuses on the modifications of polymer-based membranes for salinity gradient energy generation. Finally, some challenges and future perspective of SGE development are discussed.