New desalination technique ready for...

New desalination technique ready for commercialization.

Traditional water desalination either relies on expensive filters (to remove salt), or boilers to produce steam, which is then condensed into clean drinkable water. Now a new technique known as forward osmosis could be set to change the industry, as it’s at least 10 times more fuel efficient than current processes.

After founding Oasys Water several years ago, Robert McGinnis set to find a way to extract clean water without having to use the huge amounts of energy needed to heat water to boiling (212°F/100°C):

Water molecules naturally want to flow from fresher solutions to saltier ones. Hence the “reverse” in reverse osmosis: It forces water molecules to go against their tendency. McGinnis’s method makes use of forward osmosis. He’s developed a “draw solution” that’s saltier than seawater. Without need for any energy, the water molecules in seawater flow across a porous membrane and into the draw solution, leaving the sea salt behind. McGinnis’s solution is as undrinkable as ocean water, but its salt compounds—”essentially just ammonium, carbon dioxide, and some other secret stuff,” he says—vaporize at lower temperatures. McGinnis’s solution needs only 122F [50°C] to burn off salts and leave behind pure water, instead of the much higher temperatures required for thermal desalination.