(Last modified: January 12, 2023)
Seawater Treatment Solutions
Seawater is used in many applications, from cooling water for power plants to desalination for drinking water. As it contains high levels of chloride, materials that come in contact with seawater must have high chemical resistance, such as polymers or special alloys. Seawater also has a high organic and mineral content and must be filtered to protect downstream systems such as heat exchangers in cooling systems or membranes in desalination systems.
Applications
Here is a brief explanation of the applications using seawater in their processes which require filtration:
MF / UF Protection
Effective prefiltration is essential to protecting and improving the integrity of microfiltration/ultrafiltration membranes and maximizing their performance and lifespan. Filtration reduces the particle load, especially those that can cause mechanical damage and saves flushing water, energy and chemical use.
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Typical filtration degree: 50-500 micron Filtration to protect MF/UF membranes is needed to: |
| • Improve the integrity of the membranes • Maximize performance, increase membrane reliability and lifespan • Reduce the particle load • Extend the time between backwash and CIPs • Reduce chemical use • Prevent blockage of hollow fibers by large solids |
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Benefits of filtration for MF/UF membranes: |
| • Saves flushing water • Saves energy • Reduces chemical use • Improved membrane flux rate • Provides increased membrane reliability • Extends membrane lifespan |
NF / RO Protection
Fine filtration is required by nanofiltration and reverse osmosis membrane manufacturers as a pre-treatment process to prevent clogging and physical damage to the membrane surface and layers, and to reduce the formation of biofilm.
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Typical filtration degree: 2-20 micron Filtration to protect NF/RO membranes is needed to: |
| • Prevent clogging and physical damage to the membrane surface and layers • Reduce the formation of biofilm • Reduce chemical use • Lower energy costs • Save on membrane replacement |
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Benefits of filtration for NF/RO membranes: |
| • Reduces chemical use • Lowers energy costs • Reduces the need for membrane replacement |
Cooling Water
Power generation plants and large production facilities typically require a large quantity of cooling water and thus are often located near the sea. This cooling water is used for once-through cooling to lower the temperature of critical equipment. Cooling water filtration is often required at the intake to protect the process, and at the discharge point in order to follow strict environmental regulations.
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Typical filtration degree: 10-200 micron Filtration of cooling water is needed to: |
| • Reduce the contamination loads to allow more cycles on the cooling tower • Protect the heat exchanger • Adhere to strict environmental regulations • Ensure stable and effective processes • Lower energy costs |
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Benefits of cooling water filtration: |
| • Saves costs • Ensures stable and effective processes • Ensures adherence to environmental regulations |
Offshore Filtration: Injection Water
In the oil industry, water injection is where water is injected into the oil field to increase pressure and production, and to improve oil recovery rates. Produced water, contaminated with hydrocarbons and solids, needs treatment prior to disposal or reinjection. Seawater is a source of intake water for offshore production facilities and the intake is placed at a sufficient depth to reduce the concentration of algae. Both the produced water and the seawater require filtration in order to protect equipment and the wells themselves.
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Typical filtration degree: 10-80 micron Filtration of injection water is needed to: |
| • Reduce the contaminating loads • Protect the wells • Keep injection systems functioning reliably • Increase efficiency • Compliance with environmental regulations |
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Benefits of injection water filtration: |
| • Maintains system reliability • Increases efficiency |
Produced Water
Produced water is water associated with the production of oil and/or natural gas from wells. It may also include water produced from reservoirs or injected into wellbores to improve hydrocarbon recovery. Strict environmental regulations require produced water to be recovered and reused, and filtration is required.
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Typical filtration degree: 10-80 micron Filtration of produced water is needed to: |
| • Reduce the contaminating loads • Protect the wells • Improve hydrocarbon recovery rates • Increase efficiency • Compliance with environmental regulations |
| Benefits of produced water filtration: |
| • Maintains system reliability • Increases efficiency |
FAQs
Can I use any filter for seawater?
No. Seawater has a high level of chloride, so a seawater filter needs to be chemical-resistant (made of polymers of special alloys).
What are the main benefits of seawater filtration?
This depends on the application. However, in general, seawater filtration increases efficiency, ensures stable and effective processes, saves costs and resources, and last but not least, in many cases seawater filtration is required to comply with environmental regulations.
Is pre-filtration recommended for protecting membranes?
Yes. Filtration is an effective, cost-saving way to protect and extend the lifespan of MF (microfiltration), UF (ultrafiltration), NF (nanofiltration) and RO (reverse osmosis) membranes.
We go into more detail on our website’s seawater application page.
For more information:
