Pressure-Retarded Osmosis

Pressure retarded osmosis, or PRO, is a technique for separating a solvent, such as fresh water, from a more concentrated and pressurized solution, such as seawater. A semipermeable membrane allows the solvent to pass through to the concentrated solution side by osmosis, and the technique can be used to generate power from the salinity gradient energy created by the difference in salt concentration between sea and river water. Pressure retarded osmosis and reverse electrodialysis are the two practical methods developed for generating this salinity gradient power, also called osmotic power or blue energy. The method of generating power by pressure retarded osmosis was invented by Sidney Loeb in 1973 at Ben-Gurion University in Beersheba, Israel, partly inspired by his observation of the Jordan River flowing into the Dead Sea.