Toray has created a seawater desalinating reverse osmosis (RO) membrane that makes it possible to produce 70% more clean drinking water than conventional offerings. It is thus the world’s most energy-effective seawater RO membrane.
RO is a water production technology using semipermeable membrane. By applying pressure higher than osmotic pressure of feed water, RO membranes can exclude sodium, calcium, and other metal ions, chloride, sulfate, and other anions, and such low-molecular organic compounds as agrochemicals.
Providing clean water and sanitation for all people is one of the United Nations’ Sustainable Development Goals. This is a major challenge in a world facing ever greater water shortages and water pollution.
Figure 1. Nanostructure of RO membrane’s separation functional layers
Technological advances with RO membrane-based water treatment has lowered water production costs. The adoption of this technology to help solve water issues has progressed around the globe, particularly among desalination plants in the Middle East. The world is on the cusp of deploying huge plants with daily production of many thousands to millions of metric tons of water. Hopes are rising for technologies that can deliver excellent water quality and production rate while constraining energy consumption.
The issue with conventional RO membranes, however, is that they pose a tradeoff, with water quality declining as water production rate rises, prompting a need to develop new technology.
To date, the company utilized the top-class nanomaterial analysis capabilities of Toray Research Center as part of its research and technology development program to undertake ultrafine-structural analysis of RO membranes with nanometer-sized (a billionth of a meter) separation functional layers. The company accordingly identified the relationships between protuberance structures and water production rate and between pore structures and water quality.
This effort culminated in Toray developing a new precision interfacial polymerization technology for forming a separation functional layer, simultaneously controlling the surface area and thickness of the protuberance structure and pore diameter. This has made it possible to selectively and efficiently produce pure water from seawater, thus maintaining quality while boosting water production.
This new membrane technology aims for a solution to restore the environment and to resolve water shortage, allowing everyone enjoy access to clean water. Toray pursues this vision by leveraging its research and technological development of innovative technologies and advanced materials.