Forward-osmosis patent filed by QuantumSphere
Another forward-osmosis process has taken a step forward. QuantumSphere Inc filed for a US patent on 14 January 2009 for its water purification process, which, it claims, serves as a more energy-efficient alternative to desalination methods now commonly used.The QuantumSphere forward-osmosis process uses certain organic solutions to separate water from salty or polluted water in an osmotic purification process. The company has constructed a prototype system that can purify several gallons of water a day for demonstration purposes and intends to scale the process with large development partners to serve large-scale municipal drinking supplies.
The process uses a semi-permeable membrane to separate water from salt water into a special organic solution across the membrane. The diluted organic solution is then warmed to cause the specially formulated organic solute to drop out, leaving only fresh drinking water after a final purification step through activated charcoal.
Subra Iyer, principal technologist for QuantumSphere, based in Santa Ana, California, said, "The reverse-osmosis process requires tremendous amounts of energy for desalination. The forward-osmosis process we've developed can purify water at less than 3,000 kWh per acre foot (2.43 kWh/m³), which is approximately 70% cheaper than the energy cost of traditional reverse-osmosis processes."