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US 4,193,267 AGranted
Method and apparatus for generating power utilizing pressure-retarded osmosis
AssigneeBen-Gurion University of the Negev Research and Development Authority
InventorSidney Loeb
Life of this patent
Estimating the term…
Abstract
A method and apparatus are described for generating power utilizing press-retarded osmosis, in which a concentrated solution at a high hydraulic pressure is passed along one face of a semi-permeable membrane, and a dilute solution at a low hydraulic pressure is passed along the opposite face of the membrane to effect, by pressure-retarded-osmosis, the passage of at least a part of the dilute solution through the membrane forming a pressurized mixed solution. The potential energy stored in the pressurized mixed solution is converted to useful energy by depressurizing and repressurizing only the dilute solution.
Claims15
A method of generating power, comprising:
- (A) introducing at a high hydraulic pressure a first liquid, constituting a concentrated solution, of a high osmotic pressure into a first pathway which is at least partially defined by one face of a semi-permeable membrane;
- (B) introducing at a lower hydraulic pressure a second liquid, constituting a dilute solution, of a lower osmotic pressure into a second pathway which is at least partially defined by the opposite face of the semi-permeable membrane;
- (C) maintaining the hydraulic pressures of the liquids on the opposite faces of the membrane at a pressure difference which is less than the osmotic pressure difference between the liquids, to effect, by Pressure-Retarded-Osmosis, the passage of a part of the solvent of the dilute solution through the semi-permeable membrane, forming a pressurized mixed solution of greater volume than said concentrated solution introduced into said first pathway;
- (D) and converting the potential energy stored in the pressurized mixed solution to useful energy by:
- (i) pressurizing a quantity of liquid taken as a flushing solution from the second pathway at a point downstream of the semi-permeable membrane and adding same to the pressurized mixed solution;
- (ii) thermally separating said pressurized mixed and flushing solutions to regenerate said concentrated and dilute solutions while both are pressurized;
- (iii) recycling said pressurized, regenerated concentrated solution back through said first pathway;
- (iv) depressurizing said pressurized, regenerated dilute solution to produce useful energy;
- and
- (v) recycling the depressurized dilute solution back through said second pathway.
7 more elements
A heat-engine for generating power, comprising:
- (A) a semi-permeable membrane unit having a first pathway therethrough defined by one face of a semi-permeable membrane, and a second pathway therethrough defined by the opposite face of the semi-permeable membrane;
- (B) means for introducing at a high hydraulic pressure a first liquid, constituting a concentrated solution, of a high osmotic pressure into said first pathway;
- (C) means for introducing at a lower hydraulic pressure a second liquid, constituting a dilute solution, of a lower osmotic pressure into said second pathway;
- (D) means for maintaining the hydraulic pressures of the liquids on the opposite faces of the membrane at a pressure difference which is less than the osmotic pressure difference between the liquids, to effect, by Pressure-Retarded-Osmosis, the passage of a part of the solvent of the dilute solution through the semi-permeable membrane, forming a pressurized mixed solution of greater volume than said concentrated solution introduced into said first pathway;
- (E) and means for converting the potential energy stored in the pressurized mixed solution to useful energy, said latter means including:
- (i) pressurizing means for pressurizing a quantity of liquid taken as a flushing solution from the second pathway at a point downstream of the semi-permeable membrane unit;
- (ii) thermal separation means for separating said pressurized mixed and flushing solutions to regenerate said concentrated and dilute solutions, both pressurized;
- (iii) recycling means for recycling said pressurized, regenerated concentrated solution back through said first pathway through the semi-permeable membrane unit;
- (iv) depressurizing means for depressurizing said regenerated dilute solution to produce useful energy;
- and
- (v) recycling means for recycling the latter dilute solution back through the second pathway through the semi-permeable membrane unit.
8 more elements
Dependencies are inferred from the claim text.