Seawater Reverse Osmosis

Lewabrane SWRO membranes - seawater desalination for pure water

As approx. 97 % of all the water on earth is seawater, its desalination and use for agricultural and drinking purposes appears especially attractive. This is even more the case as technologies are available which allow performing such desalination in an energy-efficient, environmentally friendly manner. Reverse osmosis (RO) is such a technology.

The Lewabrane®RO S type is the new Reverse Osmosis (RO) spiral wound element for seawater desalination. The chemistry of this membrane is a higher cross-linking of the polyamide layer. This higher degree of polymerization improves the mechanical and chemical stability of the thin barrier layer offering greater durability and a more stable rejection of mixed ion salt solutions and organic periods.

The Lewabrane® RO S type product family was designed to meet and exceed the nominal performance standards for desalination and is offered in both high rejection (HR) and high flow (HF) product types. Three different sizes of the series are available RO S400, RO S440 and RO S085. The RO elements RO S400 and RO S440 have a standard length of 40 inches (1,016 mm) and a diameter of 8-inches (201 mm) suitable for use within standard RO membrane equipment. The product family also includes a 4-inch (101 mm) RO element suitable for smaller applications. All 8-inch diameter elements meet today’s industry standards for RO membrane surface area at 400 and 440 square feet per 8-inch by 40-inch element.

Key attributes of the new Lewabrane® RO S HR type:

  • Low salt passage
  • More stable salt rejection during operating lifetime
  • High rejection of critical ions

Key attributes of the new Lewabrane® RO S HF type:

  • High flow productivity
  • Low salt passage at high fluxes
  • Low energy demand

Comprehensive system design

With LewaPlus™, LANXESS offers comprehensive design software for RO membrane and ion exchange resin (IEX) systems in several languages. It can handle Lewabrane® RO membranes as well as Lewatit® ion exchange resins, allowing the system designer to seamlessly move from RO to IEX within the same software. Especially for seawater treatment, it offers different energy recovery methods like turbocharger or isobaric device and more than 5,000 configuration alternatives including split pass, booster pump or concentrate recirculation to different passes.