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R&D Focus

The PolyE Membrane Technology

As issues such as population growth and global warming remain, the availability of fresh water is becoming a major concern. One important technology in meeting our freshwater needs is reverse osmosis (RO); however, it requires high hydraulic pressure and thus high energy consumption to ensure its production rate. The PolyE Membrane Technology developed by ITRI uses a special layer design to combat this problem. It is the world’s first commercially viable nano-fibrous thin film composite membrane, which can desalinate water with a much lower hydraulic pressure without compromising the level of water filtration.

The structure of PolyE membrane.

The structure of PolyE membrane.

The key component of PolyE is its mat layer, a non-woven web with hydrophilic and strong electrical charge characteristics, in place of the conventional porous polysulfone sheet layer. The typical RO membrane consists of three layers: an ultra-thin polyamide layer, a polysulfone layer, and a non-woven web of PET fibers supporting the polysulfone layer. The conventional polysulfone layer faces a dilemma, as it needs to be highly porous with large pores for a large flux, but if the pores are too large the hydraulic pressure will be reduced by too much. The innovative mat layer of PolyE is highly porous, but still allows the polyamide filtration film to form, creating an improved out flux of filtered water at a reduced hydraulic pressurization energy consumption. The use of ITRI’s proprietary PolyE polymer enhances the hydrophilic and electrical charge on the surface of the polyamide thin film, resulting in an increased contaminant rejection and increased out flux.

In comparison to other RO technologies, PolyE possesses the advantage of having a low operating energy cost. It is especially useful for large facilities, as it not only is very cheap to mass produce, but can also lower energy consumption by 30-80%. This energy conservation can in turn contribute to carbon reduction on a larger scale. Simply put, it is the most cost-effective RO technology available today.

PolyE membrane modules of various sizes.

PolyE membrane modules of various sizes.



The principal application of this high-performance, low-energy-consumption membrane is for desalination, producing freshwater from seawater. With PolyE, utility-scale seawater desalination can be implemented at a lower energy cost. Additionally, with minor engineering adjustments using the same fundamental technology, PolyE will be able to perform brackish water treatment, water softening and purification for domestic and industrial purposes.