Optimization of Energy Recovery Seawater Reverse Osmosis Desalination Systems
* What is the minimum energy cost possible for seawater desalination using existing energy recovery technologies in an optimized total system?
* Is pilot scale system performance directly scalable to full scale?
Need and Benefit
There is a continuous need for less expensive water for potable and nonpotable sources. This is especially the case for ocean and brackish water sources, which traditionally have been relatively expensive to treat. The use of ocean and brackish water sources allows for continued population growth in areas that are water restricted and can reduce the reliance on overstressed rivers.
A key factor in reducing desalination costs has been improved energy recovery devices such as the pressure exchanger. Existing pressure exchanger technology has been shown to achieve two kilowatts per cubic meter (kWh/m[^3]) of produced water, but at lower recoveries of 30 percent. The goal for this pilot test is to achieve 1.5 kWh/m(^3) of produced water. It is important to evaluate energy recovery devices as a component of an entire reverse osmosis (RO) system and not as a stand-alone unit.
A part of making water available at a more affordable cost is ensuring that those involved in water treatment know the actual costs of the technology. The perception that RO treatment of seawater and brackish water is too expensive because of energy costs needs to be changed in order to have these advanced treatment options utilized.
Plant Structures, Technical Service Center
Independent Peer Review
The following documents were reviewed by qualified Bureau of Reclamation employees. The findings were determined to be achieved using valid means.
Affordable Desalination Collaboration, Phase II Progress - IDA 2007 Conference Presentation (interim, PDF,
By John MacHarg and Tom Seacord
Publication completed on September 25, 2007
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Optimizing Seawater Reverse Osmosis for Affordable Desalination - CA Proposition 50 DWR Final Report (final, PDF,
By John MacHarg
Report completed on August 30, 2012