A system and method for producing very high concentration brine streams from which commercially efficiently obtained minerals may be obtained is produced by a dual membrane brine concentrator system (DTRI Concentrator). The system includes a nano-filtration system which removes divalent ions from the seawater, a brine concentrator such as a hollow fine fiber forward osmosis system which receives and further concentrates the brine rejected from the nano-filtration system, a SWRO system which receives the NF system permeate and removes monovalent ions, and another brine concentrator which further concentrates the brine rejected from SWRO system. Various permeate and reject brine flow may be forwarded through the Dual Membrane Brine Concentrator system, and multiple stages of the system components may be used, to enhance brine concentration and improve system efficiency.

A method and system of generating electrical power or hydrogen from thermal energy is disclosed. The method includes separating, by a selectively permeable membrane, a first saline solution from a second saline solution, receiving, by the first saline solution and/or the second saline solution, thermal energy from a heat source, and mixing the first saline solution and the second saline solution in a controlled manner, capturing at least some salinity-gradient energy as electrical power as the salinity difference between the first saline solution and the second saline solution decreases. The method further includes transferring, by a heat pump, thermal energy from the first saline solution to the second saline solution, causing the salinity difference between the first saline solution and the second saline solution to increase. The method may include a process of membrane distillation, forward osmosis, evaporation, electrodialysis, and/or salt decomposition for further energy efficiency and power generation.

Methods and systems for use of switchable water, which is capable of reversibly switching between an initial ionic strength and an increased ionic strength, is described. The disclosed methods and systems can be used, for example, in distillation-free removal of water from solvents, solutes, or solutions, desalination, clay settling, viscosity switching, etc. Switching from lower to higher ionic strength is readily achieved using low energy methods such as bubbling with C0.sub.2, CS.sub.2 or COS or treatment with Bronsted acids. Switching from higher to lower ionic strength is readily achieved using low energy methods such as bubbling with air, inert gas, heating, agitating, introducing a vacuum or partial vacuum, or any combination or thereof.

A method of treating a liquid. The method comprises providing a feed liquid comprising at least one solvent and at least one solute to a first side of a membrane. A single-phase draw solution comprising at least one of an aminium salt, an amidinium salt, and a guanidinium salt is provided to a second side of the membrane. The at least one solvent is osmosed across the membrane and into the single-phase draw solution to form a diluted single-phase draw solution. At least one of CO.sub.2, CS.sub.2, and COS is removed from the diluted single-phase draw solution to form a first multiple-phase solution comprising a first liquid phase comprising the at least one solvent, and a second liquid phase comprising at least one of an amine compound, an amidine compound, and a guanidine compound. A liquid purification system is also described.

An osmotic power generator comprising an active membrane supported in a housing, at least a first chamber portion disposed on a first side of the active membrane for receiving a first electrolyte liquid and a second chamber portion disposed on a second side of the active membrane for receiving a second electrolyte liquid, a generator circuit comprising at least a first electrode electrically coupled to said first chamber, and at least a second electrode electrically coupled to said second chamber, the first and second electrodes configured to be connected together through a generator load receiving electrical power generated by a difference in potential and an ionic current between the first and second electrodes. The active membrane includes at least one pore allowing ions to pass between the first and second sides of the membrane under osmosis due to an osmotic gradient between the first and second electrolyte liquids to generate said difference in potential and ionic current between the first and second electrodes.

A process for the absorption of a target gaseous component from a gas stream comprising the steps of: contacting the gas stream with an absorber comprising an liquid absorbent for absorbing the target gaseous component to produce a rich liquid absorbent stream and a non target gaseous component, said non target gaseous component including water vapour; treating the rich liquid absorbent stream in a desorber to thereby release the target gaseous component and a water vapour component into a desorber gas stream and produce a lean liquid absorbent stream; and forming a recovered water stream from the output of a water separator for separating the water vapour from the target gaseous component, said water separator forming part of the absorber and/or the desorber. The lean liquid absorbent stream exiting the desorber is treated with a forward osmosis (FO) membrane unit comprising a water permeable membrane, wherein the membrane unit transfers water from a salt water stream through the water permeable membrane to the lean liquid absorbent stream, thereby replenishing at least part of the water removed in the process.

The invention relates to membranes, membrane modules, and applications therefor. In particular, the invention relates to the construction of membranes for use in osmotically driven membrane processes.

A sheet-shaped hollow fiber membrane module includes a casing having a flat shape, the casing including a supply port and a discharge port, and a plurality of hollow fiber membranes accommodated inside the casing. The casing includes a plurality of the supply ports on one main surface of the casing and a plurality of the discharge ports on the other main surface of the casing, at least one of the plurality of the supply ports is closable, and at least one of the plurality of the discharge ports is closable. Each of the plurality of hollow fiber membranes includes a first opening at one end of the hollow fiber membrane and a second opening at the other end of the hollow fiber membrane, and the first opening and the second opening communicate with an outside of the casing and do not communicate with an inside of the casing.

A system feed inlet is connected to a forward osmosis (FO) element bank. A system feed transfer directs fluid flow from the FO element bank through a system feed outlet to a second FO element bank through a system feed inlet. A system draw transfer directs indirect fluid flow from the second FO element bank to the first FO element bank.

The present invention relates to a desalination apparatus and a desalination method using the same. In one specific embodiment, the desalination apparatus comprises: a forward osmosis unit having a draw-solution part into which seawater flows, and a raw water part into which raw water flows, and having an osmosis membrane, formed between the draw solution part and the raw water part, so as to respectively generate first treated water and first concentrated water; a capacitive deionization unit, which is connected to the draw solution part through a first inflow passage, and into which the first treated water of the draw solution part flows so as to generate second treated water; and an electrodialysis unit, which is connected to the raw water part through a second inflow passage, and into which the first concentrated water of the raw water part flows so as to generate third treated water.