Harnessing salinity gradient power and brine valorization through reverse electrodialysis for sustainable energy in Morocco
Аннотация
This study investigates the feasibility of using Reverse Electrodialysis (RED) technology to generate energy in Morocco, leveraging the country’s seawater and industrial brine resources. The Phosboucraa desalination plant in Laâyoune serves as a case study to assess the energy production potential of different water streams, including brine (60 g/L), reverse osmosis (RO) permeate water (5 g/L), seawater (35 g/L), and phosphate-washing wastewater (44.35 g/L). The results indicate that the highest energy output of 180 kW is achieved when brine is paired with RO permeate water, owing to the significant salinity gradient of 55 g/L, which maximizes electrochemical potential. Conversely, the lowest energy output of 6 kW is observed when brine is combined with phosphate-washing wastewater, which limits the ion exchange process. Treated wastewater from the tertiary stage of the Membrane Bioreactor (MBR) process, with a salinity of 3.33 g/L, achieves an energy output of 160 kW and presents a viable alternative to RO permeate. The system, configured with 400 cells and a membrane area of 5 m 2 , is designed to treat brine at a flow rate of 135 m 3 /h. Economic analysis indicates that the brine-permeate scenario (BW/PW) could generate an annual revenue of approximately €157,680, while the brine-wastewater scenario (BW/WW) results in a lower annual revenue of around €140,160. This highlights the significant impact of the salinity gradient on profitability.