Desalination R&D project completed by Siemens, sets new benchmark on low-energy seawater desalination

Sponsored by
A Siemens R&D engineer examines a state-of-the-art seawater desalination prototype in Singapore. Photo: Siemens AG

SINGAPORE, July 5, 2011 -- A Siemens research and development initiative has shown that a new desalination process reduces desalting energy by over 50% compared to best available technology.

The research was conducted at a demonstration plant built in Singapore to treat seawater to drinking water quality. Since December 2010, the Siemens demonstration unit has been treating 50 m³ of seawater per day at a PUB facility in Singapore.

The project goal was to produce World Health Organization standard drinking water quality from seawater, at the same time cutting energy consumption by half compared to current technologies. Instead of using reverse osmosis, which requires high-pressure pumps to force water through semi-permeable membranes, the Siemens engineers turned to electrochemical desalination. The process combines electrodialysis (ED) and continuous electrodeionization (CEDI), both applying an electric field to draw sodium and chloride ions across ion exchange membranes and out of the water. As the water itself does not have to pass through the membranes, the process can be run at low pressure, and hence low power consumption.

The seawater is pre-treated with a self-cleaning disk filter, followed by Memcor ultrafiltration modules. The pilot desalination plant is composed of three ED units arranged in series to handle high concentrations of salt. They are followed by three CEDI units assembled in a parallel flow configuration to remove smaller amounts of salt.

The energy demand of the whole process including pumping, pre-treatment, desalting, and post-treatment is less than half of what is used by the best available seawater desalination technologies today, which is typically between 3.4 and 4.8 kWh/m³. Besides the energy savings, other advantages are low vibration and noise levels, improved safety, and only minimal pre- and post-treatment.

Siemens said it is now poised to transition this new technology to the product development phase. The next step will be to set up a full-scale system in cooperation with Singapore's national water agency PUB by 2013.

###

Sponsored by

TODAY'S HEADLINES

VIDEO: Detector tracks toxic algae blooms in drinking water

A biosensor recently developed at Lund University in Sweden could be used to detect toxic algae blooms in drinking water...

Pre-treatment contract awarded for Basra, Iraq desalination project

Iraqi Ministry of Municipalities and Public Works has awarded a 170 million euro contract to provide pre-treatment facilities for its 200,000 m3/day desalination plant awarded earlier this year...

Clearing Things Up at Pequannock WTP

In 2010, the city of Newark, N.J., retained Hatch Mott MacDonald to investigate potential solutions to a problem at Pequannock WTP. Decant tanks were providing minimal solids removal as a result of removed tube settlers from deterioration. Inclined plate settlers were identified as a feasible alternative for improving supernatant water quality and were selected for pilot testing.

Be the Change: Embracing New Approaches to Foster Innovation in the Water Industry

The pressure to accommodate change will drive our traditionally risk-averse industry to embrace new and different approaches at an accelerated pace. Further, the demand for a zero-energy footprint will also drive improvements in co-generation efficiencies, energy conservation and recovery methods, and comprehensive resource recovery.

FOLLOW US ON SOCIAL MEDIA