French-based water treatment and waste management solutions provider Suez Environnement has signed a research contract with United Arab Emirates-based university the Masdar Institute of Science and Technology and Abu Dhabi Future Energy Company to study seawater desalination, with a plan to construct a pilot seawater desalination plant that will, potentially, be 100% powered by renewable energy.
The pilot plant will be situated in Ghantoot, about 80 km outside Abu Dhabi and is currently midway through the construction phase.
Masdar project manager Jerome Piens explains to Engineering News that Suez Environnement is trying to optimise energy efficiency in both the solar power generation process and the seawater desalination process.
The research, which is currently under way, is linked to a project being run by Suez Environnement and Masdar to construct a pilot seawater desalination plant. This project was contractually agreed on in June 2014, after which planning began.
The research contract, signed in January 2015 with Abu Dhabi Future Energy Company, is geared towards finding ways to generate solar power efficiently enough to power the seawater desalination plant.
Piens explains that Suez Environnement’s France-based engineering team is currently buying the equipment and construction elements of the plant in Belgium and the Middle East.
The desalination plant, which will cost between €5-million and €6-million, is funded by both Suez Environnement and Masdar and is geared towards developing optimal methods of desalination.
At this plant, 100 m3/d of water will be desalinated and powered, for now, by normal electricity.
Highlighting the usual three-step process of desalination, Piens explains that raw seawater is pumped into the plant for pretreatment. In this process, all contaminants, such as algae, are removed by air flotation and filtration to produce clean saltwater.
After the pretreatment phase, clean saltwater is desalinated through reverse osmosis to produce a permeate, or desalinated water. The reverse-osmosis process also leaves behind brine with double- salt content.
Piens explains that, unlike a standard desalination plant that simply disposes of the brine, this desalination plant will employ a new method whereby part of the brine will be desalinated with liquid extraction resins to achieve a greater volume of desalinated water.
He adds that Suez Environnement is experimenting with different membranes to optimise energy consumption.
The last phase of the desalination process, potabilisation, involves the remineralisation of water so that it can be used domestically.
While Piens is unable to provide Engineering News with a precise figure on the pilot plant’s expected energy consumption, he states that the plant’s consumption will depend on the method that will be used to apply the liquid extraction resins. Piens adds that, with similar projects on a greater scale, the energy consumption could be much more efficient.
Typically, a normal process of desalination requires a range of between 4 Wh/m3 and 10 kWh/m3, which Piens believes could be reduced.
Since the start of the project in June 2014, no major changes have had to be made in terms of the process to be followed. However, owing to the high temperatures in Ghantoot and the high salinity of the seawater in the area, the material selection for some smaller equipment had to be altered to ensure that the plant’s components are able to withstand the stringent conditions.