Brine utilization for blue energy generation: Life HyReward project
Clara Calvo Barahona1*, Patricia Terrero Rodríguez1, Sofía Pastor González1, Simon Grasman2, Hendrik Swart2, Frank Scheepers3, Domingo Zarzo Martínez1
1Sacyr Agua, C/ Condesa de Venadito, 7, Madrid 28027, Spain
2REDstack, Hermes 8, 8448 CK Heerenveen, The Netherlands
3Pure Water Group, Korte Hei 3, 4714 RD Sprundel, The Netherlands
*Corresponding author
https://doi.org/10.5004/po2024130
ABSTRACT
The Life HyReward project, funded by the European Union, seeks to validate the technical and economic viability of a more environmentally friendly desalination approach by integrating reverse osmosis (RO) with reverse electrodialysis (RED). RED technology generates blue energy—a renewable, emission-free form of electricity—by harnessing the salinity gradient between two solutions with different salt concentrations. Within the framework of the project, the brine produced by the reverse osmosis process is utilized as the high-salinity input, while treated wastewater functions as the low-salinity counterpart. The osmotic gradient between these streams enables the production of clean electricity, which can be fed back into the system. This method has the potential to recover up to 20% of the energy expended in the reverse osmosis stage, thereby enhancing the energy efficiency and reducing the overall power demands of desalination. Pilot-scale trials delivered encouraging results, achieving energy outputs of up to 0.31 kWh/m3 of brine, which contributes to a significant reduction in the total energy consumption of the reverse osmosis process, which ranges between 2.5 and 4 kWh/m³ in the case of large seawater desalination plants. These outcomes highlight the promise of RED as a complementary technology for improving desalination systems while lowering their environmental footprint and energy usage.
Keywords: Desalination; Reverse electrodialysis; Blue energy; Reverse osmosis; Energy efficiency; Sustainability
