Processing Magazine

Lockheed Martin develops innovative desalination membrane

March 26, 2013
Lockheed Martin Perforene desalination membrane
Lockheed Martin’s Perforene membrane features holes one billionth of a meter or less in a graphene sheet that trap sodium, chlorine and other ions from seawater.

Lockheed Martin, a company that specializes in research and development of advanced technology systems in a number of sectors, including security and aerospace, has been awarded a patent for its latest invention -- Perforene material, a molecular filtration solution that can turn seawater into fresh water and may help to meet the increased demand for potable water worldwide.

The Perforene desalination membrane is made of single-atom thick sheets of graphene. The material is designed in a way that allows water molecules to pass through the membrane easily, while dissolved salts are prevented from going through thanks to the carbon web, which captures sodium, chlorine and other ions, Lockheed Martin explained. It was created by placing holes that measure a maximum of one nanometer in a graphene membrane. These openings are small enough to prevent the ions from passing through but significantly improve the flow-through of water molecules by reducing clogging, the company explained.

Previous desalination methods treated seawater either by pushing salt water through a number of filters at high pressure or by catching the steam from heated water. However, both methods are very energy-demanding because they need pressure or heat to do the job. By contrast, the Lockheed Martin filter is 500 times thinner than the best filter on the market today and a thousand times stronger, according to the developers of the technology, quoted by Reuters. Meanwhile, the graphene filtration method uses 100 times less energy than current saltwater filtration systems, Lockheed Martin engineer John Stetson told Reuters. Its strength and durability can be attributed to the fact that graphene has a thickness of only one atom, thus making it very effective and much cheaper than other desalination methods that rely on reverse osmosis.

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According to Dr Ray O. Johnson, senior vice president and chief technology officer of Lockheed Martin, the Perforene membrane is a "simple and affordable" solution to the global water management challenges presented by growing population and extreme water scarcity in certain areas. Over the coming decades access to clean water will be of critical importance and Lockheed Martin could have the key to tackling the problem, he added.

The company announced that it was developing processes for producing the material and was currently looking for commercialization partners. According to Reuters, Perforene might be available on the commercial market as a filter by 2014 or 2015.