Up to now, evaporation and reverse osmosis technology have been used as the standard to produce water from seawater. However, it has disadvantages such as high energy consumption and high pressure is required for evaporation and RO, respectively.

Recently, it is predicted that Forward Osmosis (FO) can substitute the use of RO in desalination because the water can pass the FO membrane naturally due to the osmotic pressure difference between feed and draw solution.

Further, distillation technology is used to recover the draw solution and obtaining the water product. This FO-distillation technology uses Ammonium Bicarbonate as a draw solution. In the column, NH and CO are vaporized so that the energy consumption is smaller than water evaporation. Moreover, the low-temperature waste heat can be used as the heating medium in the reboiler.

However, it was found that there is a tendency to have a problem with precipitation of ammonium bicarbonate salt in the column during the operation.

Therefore, Benit M patented a novel process design configuration to effectively regenerate Ammonium Bicarbonate Draw Solution and produce water without any plugging or fouling trouble in the column.