Seawater desalination with reverse osmosis (SWRO) has taken a noteworthy upturn during recent years. One of the reasons for the success of the membrane process is its lower energy consumption in comparison with thermal desalination processes. The high-pressure RO desalination stage is undoubtedly the dominating energy consumer of an SWRO plant. Energy consumption of SWRO, despite its energy-recovery aspects, is also influenced by a huge number of additional factors. These are both of an external nature (eg, environmental conditions and stipulations), but are also determined by design and configuration of the plant. On the basis of an SWRO plant model, which covers the different pre-treatment and RO configurations and also the design with energy consumption of potabilisation and additional wastewater treatment and sludge dewatering facilities, the specific energy consumption of an SWRO and its subsystems has been determined in this article. Considering the various aspects to be taken into account for optimization of energy consumption in seawater reverse osmosis plants and the fact that in most cases these measures are offset by increases in capital costs for equipment or possibly also in chemical consumption, optimisation of the energy consumption of SWRO plants during planning and operation is a quite extensive and complicated matter and a demanding engineering task. This article is an expanded and updated version of the article published in the August/September issue of D&WR magazine.
Seawater desalination with reverse osmosis (SWRO) has taken a noteworthy upturn during recent years. One of the reasons for the success of the membrane process is its lower energy consumption in comparison with thermal desalination processes.
The high-pressure RO desalination stage is undoubtedly the dominating energy consumer of an SWRO plant. Energy consumption of SWRO, despite its energy-recovery aspects, is also influenced by a huge number of additional factors. These are both of an external nature (eg, environmental conditions and stipulations), but are also determined by design and configuration of the plant.
On the basis of an SWRO plant model, which covers the different pre-treatment and RO configurations and also the design with energy consumption of potabilisation and additional wastewater treatment and sludge dewatering facilities, the specific energy consumption of an SWRO and its subsystems has been determined in this article.
Considering the various aspects to be taken into account for optimization of energy consumption in seawater reverse osmosis plants and the fact that in most cases these measures are offset by increases in capital costs for equipment or possibly also in chemical consumption, optimisation of the energy consumption of SWRO plants during planning and operation is a quite extensive and complicated matter and a demanding engineering task.
This article is an expanded and updated version of the article published in the August/September issue of D&WR magazine.