Branching out from its reputation for jet fighters and missiles, defense contractor Lockheed Martin has discovered a means for desalinating seawater that requires a fraction of the energy needed for current systems.
This could provide purified water to underdeveloped nations at a time when access clean drinking drinking water is a major security issue that can lead to instability of developing nations. According to a 2012 report from the United Nations, there are about 780 million people on Earth who do not currently have access to clean drinking water.
The process works by filtering water through nanometer-sized holes in graphene – carbon membranes that measure in with a thickness of about one atom. It's slim profile means that the energy needed to push seawater through the filter while the salt molecules are blocked out is significantly reduced from traditional filters.
“It's 500 times thinner than the best filter on the market today and a thousand times stronger,” said John Stetson, an engineer on the graphene filter project. “The energy that's required and the pressure that's required to filter salt is approximately 100 times less.”
Stetson explained that the thickness of the new filter, called Perforene, could be visualized by a single sheet of paper, whereas current filters are the thickness of three reams of paper. Because the water doesn't have to wiggle its way through a thick membrane, molecules passing through Perforene can pop right through using only one percent of the previous energy and pressure required.
Lockheed hopes that the development of this process could eliminate the need for developing nations to invest in expensive pumping stations that use reverse osmosis for desalination.
But Lockheed must still overcome a number of obstacles if they are to meet their goal. When working with atom-thin material means that delicacy is a limiting factor for upping production. Engineers are currently addressing the hole-making process so that it is less likely to reduce in tearing.
In the meantime, Lockheed is not the only one looking to make graphene filtering a reality. Jeffrey Grossman, an associate professor at MIT investigating the process commented that if Lockheed were able to refine the production process for graphene sheets with nanometer-sized holes, it would be a major advancement for desalination technology.
Full story at Reuters