Abstract: A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

Abstract: A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

Abstract: A carrier gas and a combined feed liquid are directed through a humidifier, where water vaporizes from the combined feed liquid into the carrier gas, and through a dehumidifier, where the combined feed liquid cools the carrier gas to condense water from the carrier gas. At least a portion of the concentrated brine stream from the humidifier is directed through a pressure-retarded osmosis unit, while an initial feed solution is directed, in counter-flow, through the osmosis unit. Water from the initial feed solution flows through a membrane in the osmosis chamber into the concentrated brine stream to dilute and increase the volumetric flow rate of the brine stream. The diluted brine stream is extracted from the osmosis chamber and depressurized to produce power, while the concentrated initial feed solution is combined with the depressurized, diluted brine stream to form the combined feed liquid.

Abstract: A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

Abstract: A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

Abstract: A carrier gas and a combined feed liquid are directed through a humidifier, where water vaporizes from the combined feed liquid into the carrier gas, and through a dehumidifier, where the combined feed liquid cools the carrier gas to condense water from the carrier gas. At least a portion of the concentrated brine stream from the humidifier is directed through a pressure-retarded osmosis unit, while an initial feed solution is directed, in counter-flow, through the osmosis unit. Water from the initial feed solution flows through a membrane in the osmosis chamber into the concentrated brine stream to dilute and increase the volumetric flow rate of the brine stream. The diluted brine stream is extracted from the osmosis chamber and depressurized to produce power, while the concentrated initial feed solution is combined with the depressurized, diluted brine stream to form the combined feed liquid.