ACCIONA, as coordinator of the LIFE INDESAL European Innovation Project, has presented, together with its partners, the results of the pioneering high-efficiency desalination system that they have developed in recent years. This system is based on a low-pressure multistage reverse osmosis setup to produce high-quality water; reverse electrodialysis to treat the brine and harvest energy from its salinity gradient; and electrodialysis with bipolar membranes, also powered by that stream, to generate chemicals for use in the desalination process itself.
The developed pilot unit has completed a demonstration phase lasting almost two years at the Leading Experimental Accelerator in Desalination (LEAD®) at the San Pedro del Pinatar-II desalination plant.
On the one hand, stable and efficient performance has been demonstrated through high-quality permeate production (TDS < 200 mg/L), with lower energy consumption in RO technology than traditional processes, owing to lower operating pressures and more customised cleaning strategies for membrane elements.
On the other hand, renewable energy (0.1 kWh/m3 brine) has been generated, as well as on-site production of chemicals from brine. This supplies 100% of the chemicals required for cleaning procedures, which increases the plant's operational self-sufficiency.
The solution developed in the LIFE INDESAL project can be scaled for implementation in both new seawater desalination plants and partially modified plants, as well as in other industrial applications.
The project, with a budget of €3.1 million, has the collaboration of the Department of Chemical and Biomolecular Engineering of the University of Cantabria (Spain), an institution with a long history of recovering energy and materials from residual liquid and gaseous effluents; APRIA Systems, a spin-off from the University of Cantabria with experience in advanced separation technologies for the treatment and valorisation of different types of streams; REDstack, a Dutch company focused on the development and marketing of electro-membrane stacks and processes such as reverse electrodialysis, electrodialysis and related applications, and REVOLVE, a Belgian entity with extensive experience in communication in the water sector.
