Performance analysis of the first Reverse Electrodialysis prototype plant operating with natural brackish water and salt pond brine

Reverse Electrodialysis (RED) has gained a strong interest among the salinity gradient energy technologies during the last years. Recently, notable improvements have been reached in terms of membranes and stack performances using artificial solutions. However, the use of real saline solutions strongly affects the process performance, requiring additional R&D efforts for a successful scale-up of such technology. This work focuses on the experimental campaign performed on the first RED prototype plant fed with real brackish water and saltworks brine. The plant is located within the Ettore e Infersa saltworks in Marsala (TP, South of Italy). It is the final accomplishment of the REAPower proje…

CFD modelling of profiled-membrane channels for reverse electrodialysis

Abstract: Reverse electrodialysis (RE) is a promising technology for electric power generation from controlled mixing of two differently concentrated salt solutions, where ion-exchange membranes are adopted for the generation of ionic currents within the system. Channel geometry strongly influences fluid flow and thus crucial phenomena such as pressure drop and concentration polarization. Profiled membranes are an alternative to the more commonly adopted net spacers and offer a number of advantages: avoiding the use of non-conductive and relatively expensive materials, reducing hydraulic losses and increasing the active membrane area. In this work, Computational Fluid Dynamic simulations we…

Magnesium recovery from exhausted brine

Mg and MgCO3 are among the 20 EU critical raw materials. Interestingly, Mg can be found at very high concentration in brines generated as waste stream from salt works. Literature works have demonstrated the feasibility of Mg extraction from brines [1–3] by reactive precipitation, for the production of Mg(OH)2. Here we present an overview of the experimental campaigns carried out using exhausted brine from real salt works (Italy) to produce Mg(OH)2 with high purity and conversion. Lab – and pilot-scale batch and semi-continuous CSTR crystallisers were developed and tested, eventually leading to a continuous process by a quasi-PFR pilot reactor. Different alkaline solutions have been adopted …

Sustainable water and energy: the EU-FP7 MEDIRAS and REAPOWER research projects