Japanese companies Hitachi Ltd and Toray Industries Inc have been commissioned by the New Energy and Industrial Technology Development Organization (NEDO) to implement a demonstration project for an energy-saving seawater reverse osmosis (RO) system in Saudi Arabia. 

Under the contract, Hitachi and Toray will work with Saline Water Conversion Corporation (SWCC), a Saudi government-owned desalination company, to design, construct and operate facilities for actual-scale demonstration of an energy saving seawater RO system with a water production capacity of 10,000 m3/ day in Ummluji, a city on the Red Sea coast. The work will also involve testing the system's performance and studying the business model to put the system to practical use, aiming to expand the operation in the country and to neighboring countries.

The demonstration project is scheduled to last approximately five years from April 2018 to March 2023.

A low pressure multi-stage high recovery seawater RO system developed by Hitachi and low-pressure seawater RO membranes developed by Toray will be used. The RO system features RO membrane vessels installed in multiple stages, which ienables control of the flow rate and pressure of the feed-water. This maximizes the performance of the RO membranes, ensuring high efficiency. An energy recovery device will reduce the energy required to drive the pump. In addition, the low-pressure membranes ensure a high salt removal rate even with low-pressure operation.

By applying these technologies, Hitachi and Toray aim to reduce energy consumption by around 20% compared to conventional seawater desalination plants applying RO membranes.

The companies also aim to lower construction cost by reducing the capacity of the pretreatment facilities, which will be enabled by lowering the seawater intake.

Hitachi and Toray have been conducting a pilot test using a small-scale (500 m3/day) plant at a SWCC research site in Al-Jubail, a city on the coast of the Arabian Gulf, since December 2016.