Future Water Supply Desalination Technology: Forward Osmosis Co-Located with Power Generation

Desalination — processes that remove excess salt and other minerals from water — is a critical technology in today's age of shrinking freshwater supplies. Currently Reverse Osmosis (RO) and thermal technologies, such as Multi-Effect Distillation (MED) and Multi-Stage Flash (MSF), dominate the desalination market. However, rising energy costs and government regulations on carbon emissions are likely to change the future of desalinating water. Seeking to identify and validate market attractiveness of emerging technologies to power and treat non-freshwater sources, the authors evaluated whether the cutting-edge membrane technology known as Forward Osmosis (FO) was a viable desalination method. Forward Osmosis (FO) uses highly concentrated carbon dioxide (CO₂) and ammonia (NH₃) to separate the freshwater from the brine. A thermal process is used to remove the CO₂ and NH₃ from the freshwater; the CO₂ and NH₃ are then recycled to be used again. The study concluded that even with its increased efficiency, FO alone will not resolve all of the world's desalination challenges. The study concluded that with its increased efficiency, FO can be successful under the proper circumstances.