Power production from salinity gradients, the so-called Pressure Retarded Osmosis (PRO), has been actively investigated and tested since the 70s for its reliability and controllability. Besides these advantages, it seems a promising green solution since it allows the dilution of highly concentrated brines and the specific energy consumption of desalination plants. Most of PRO applications, though, use freshwater as feed solution, which in some locations may be scarce or dedicated to other uses. In the present paper, PRO is researched for hypersaline solutions (brine and seawater), and a sensitivity analysis is carried out over the most significant parameters that affect the system performance: draw and feed velocities, hydrostatic pressure-osmotic pressure difference ratio and membrane length. The PRO model is then coupled to a simplified Reverse Osmosis (RO) plant into two novel integrated desalination plant layouts to quantify the PRO impact on the specific energy consumption. The two layouts are simulated with both a commercial and an experimental membrane, with a view to membrane technology improvement.
Use of Pressure-Retarded-Osmosis to reduce Reverse Osmosis energy consumption by exploiting hypersaline flows
Bargiacchi E.;Ferrari L.;Desideri U.
2020-01-01
Abstract
Power production from salinity gradients, the so-called Pressure Retarded Osmosis (PRO), has been actively investigated and tested since the 70s for its reliability and controllability. Besides these advantages, it seems a promising green solution since it allows the dilution of highly concentrated brines and the specific energy consumption of desalination plants. Most of PRO applications, though, use freshwater as feed solution, which in some locations may be scarce or dedicated to other uses. In the present paper, PRO is researched for hypersaline solutions (brine and seawater), and a sensitivity analysis is carried out over the most significant parameters that affect the system performance: draw and feed velocities, hydrostatic pressure-osmotic pressure difference ratio and membrane length. The PRO model is then coupled to a simplified Reverse Osmosis (RO) plant into two novel integrated desalination plant layouts to quantify the PRO impact on the specific energy consumption. The two layouts are simulated with both a commercial and an experimental membrane, with a view to membrane technology improvement.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
