Specialty chemicals company LANXESS has launched five new types of Lewabrane membrane separation elements for Reverse Osmosis (RO). Currently, HR (high rejection) types with membrane surface areas of 370 and 440 square feet and HF (high flow) types with membrane surface areas of 370, 400 and 440 square feet are available.
Alan Sharpe, head of the RO Membrane Strategic Project in LANXESS’s Ion Exchange Resins business unit said: “Our HR type elements are designed to provide extremely low salt passage in normal operation, with more than 99.7% salt rejection measured under standard conditions. The high rejection for critical ions like silica is also remarkable.”
The Lewabrane RO product types consist of spiral wound polyamide composite membranes specially designed for treating water in industrial applications. Fields of application include the desalination of brackish and low-salinity waters, groundwater remediation and the production of boiler feed water required in power stations. The RO technology also facilitates demineralisation by particle removal in microchip manufacture.
The elements in the Lewabrane RO product family have a standard length of 40 inches (1,016 mm) and a diameter of either eight inches (201 mm) or four inches (101 mm).
The press release pointed out that Lewabrane B090 HF 4040, the membrane element with a diameter of four inches, has a unique anti-telescopic device (ATD) design. It claimed that thanks to a structure with ATDs at the ends of the elements, surface area of the membranes exceeds that of other commercially available elements by almost six per cent, resulting in higher water productivity. The permeate flow rate, the press release continued, is 9.4 m3/day on average under standard conditions, with a salt rejection of 99.5%.
“The combination of membrane filtration and ion exchange ensures that efficiency and economy can go hand in hand in industrial applications,” said Sharpe. Since the group offers both technologies, such process combinations are particularly attractive. “Our tried and tested Lewatit ion exchange resins and the new Lewabrane membrane elements can provide good cost performance, for example in the preparation of feed water for downstream EDI applications.”
The membrane elements provide a stable lower-salinity permeate to minimise the load in downstream ion exchange and electrodeionisation (EDI) operations, thus improving the cost-performance ratio. The detailed descriptions of Lewabrane RO elements can be found online at www.lewabrane.com