As part of its suite of water solutions, Keppel Seghers also provides technologies for seawater desalination.
Common methods for large scale desalination include traditional thermal desalination and membrane based techniques such as reverse osmosis desalination.
MEMSTILL® membrane distillation is an emerging technology for desalination. It is suitable for applications in process water production, drinking water production, treatment of waste streams and concentration of brine.
Cold seawater flows through a condenser with non-permeable walls. Subsequently it flows through a heat exchanger, and from there into the membrane evaporator. The wall of the evaporator is a micro-porous hydrophobic membrane through which water vapour can diffuse and by which liquid water (with dissolved salts) is retained.
Membrane distillation differs from other membrane technologies in that the driving force for desalination is the difference in vapour pressure of water across the membrane, rather than total pressure. The vapour pressure gradient is created by heating the source water.
The highly efficient heat recovery dramatically reduces energy requirements, allowing Memstill desalination to use low grade, or even waste heat, from sources like power plants.
Our proprietary desalination system, POTABLOC, is capable of producing drinking water that meets the World Health Organisation (WHO) standards. Our containerised units can be customised to produce 240m3 to 600m3 of water a day, equivalent to supplying drinking water for 12,000 and 30,000 people respectively.
Using the membrane separation techniques, it produces potable water and process water from seawater, non brackish surface water, well water, or even biological effluent for industrial applications.
For more information, download our brochure.