Journal of Geoscience and Eco Agricultural Studies

Abstract

Only renewable energy sources should be used to produce "green" hydrogen. Salinity gradient energy, which can be obtained by reversibly mixing solutions, offers several advantages over other renewable energy sources. Salinity gradient energy sources have high potential and energy density, and are stable. Using natural solutions has minimal adverse environmental impact. Membrane methods for converting salinity gradient energy have received the most development. Pilot industrial plants using osmotic semipermeable membranes and ion-selective membranes have been created. However, the technical characteristics of currently produced membranes and their high cost make salinity gradient energy uncompetitive compared to other renewable energy sources. Direct conversion of salinity gradient energy into electrical energy is possible through reverse electrodialysis in an electrodialysis battery consisting of alternating anion- and cation-exchange membranes. The directed movement of ions through ion-selective membranes creates a potential difference across the electrodes located in the outer compartments of the battery. Voltage is applied from the electrodes of the electrodialysis battery to an external load. When inert electrodes are used, electrolysis by the solution occurs on them, lowering the battery's potential. The products of electrolysis can be utilized. Thus, the hydrogen produced during electrolysis serves as a secondary energy source. Its use allows for greater energy recovery by converting the energy of salinity gradients, increasing efficiency.