Patent ID: 8652333
Filing Date: 2014-02-18
Classification: B01D,C02F

Abstract:
1. A process for removing a solvent from a source solution, said process comprising: a) preparing a draw solution by dissolving one or more water-soluble salts in water; b) contacting the source solution with one side of a selectively permeable membrane; c) contacting the draw solution with the opposite side of the membrane, whereas the draw solution is prepared having a higher osmotic pressure (higher solute concentration) than the source solution, such that solvent from the source solution passes across the membrane to dilute the draw solution by direct osmosis; d) removing solvent from the diluted draw solution to regenerate the draw solution, and e) recycling the regenerated draw solution to step c), wherein solute species from the source solution flow across the membrane into the draw solution in the direct osmosis step, and a portion of the draw solution is discarded or treated after the draw solution is regenerated in step d), so as to reduce the concentration of solute species present in the draw solution from the source solution.