Patent ID: 9248405
Filing Date: 2016-02-02
CPC Classification: B01D,C02F,Y02P,Y02W

Claim Text:
1. A forward osmosis separation process, comprising: introducing a first solution on a first side of a semi-permeable membrane; detecting at least one characteristic of the first solution; selecting a molar ratio for a concentrated draw solution based on the at least one detected characteristic; introducing the concentrated draw solution at the selected molar ratio on a second side of the semi-permeable membrane to maintain a desired osmotic concentration gradient across the semi-permeable membrane; promoting flow of at least a portion of the first solution across the semi-permeable membrane to form a second solution on the first side of the semi-permeable membrane and a dilute draw solution on the second side of the semi-permeable membrane; introducing a first portion of the dilute draw solution to a separation operation to recover draw solutes and a solvent stream, wherein the introducing step comprises introducing the first portion of the dilute draw solution to a distillation apparatus to vaporize the draw solutes out of the dilute draw solution; introducing the vaporized draw solutes to a heat exchanger to at least partially condense the vaporized draw solutes; introducing the at least partially condensed draw solutes to an absorber; introducing a second portion of the dilute draw solution to at least one of the heat exchanger or the absorber; recycling the condensed draw solutes to the second side of the semi-permeable membrane to maintain the selected molar ratio of the concentrated draw solution; and collecting the solvent stream.