Seawater reverse osmosis at high pressures

Seawater reverse osmosis system costs can be reduced significantly by operation at the high conversions now made possible by the high pressure capabilities of aramid hollow fine fibre (HFF) membranes. Most seawater reverse osmosis membranes offered in the market place today have a maximum rated feed pressure of 800 to 1000 psig. However, aramid hollow fine fibre membranes are available with a feed pressure rating of 1200 psig and seawater plants in operation today are already demonstrating membrane capabilities of 1150 to 1200 psig operation and 50 percent conversion. Process economics show that the end user will incur lower costs at higher membrane feed pressures. It is highly probable that seawater reverse osmosis devices capable of 1300 to 1500 psig operation will appear in the near future as a result of this advantage.