Energy recovery using salinity differences in a multi-effect distillation system

The use of Salinity Gradient methodologies to recover part of the osmotic energy in the brine of multi-effect distillation (MED) systems is explored here. Measurements from a membrane-based Pressure Retarded Osmosis laboratory system have been used to estimate the energy that would be recovered from this brine, when a source of low-salinity water is available locally (such as industrial or municipal wastewater). This methodology has been evaluated for a specific case study (72 m3/d solar/gas MED system) at different temperatures.