JP2010517746A - Desalination method and apparatus including supercapacitor electrode - Google Patents

Abstract

Methods and apparatus for desalting fluids have been defined. The present invention involves releasing the solute-carrying electrode to obtain an outlet stream of solute having a higher concentration than the feed stream. Release may include supersaturing the stream, precipitating or crystallizing the stream, and recovering the solids. The liquid stream may be circulated across the electrode more than once. The device may comprise a dialysis, nanofiltration or RO device. The controller sends a signal for release.
[Selected figure] Figure 6

Description

  Embodiments of the present invention relate to the field of liquid desalting. Embodiments of the present invention relate to demineralizers and methods of using the demineralizers.

  Less than 1% of surface water is suitable for direct consumption for home or industrial use. Deionization of seawater or brackish water, generally referred to as desalination, is one of the means of producing fresh water, due to limited natural drinking water sources. There are several desalting techniques currently used for the deionization or desalting of water sources.

  Capacitive deionization is an electrostatic process that proceeds at low voltage (about 1 volt) and low pressure (15 psi). When the brackish water is pumped into the high surface area electrode assembly, ions such as salts, metals and certain organics dissolved in the water are attracted to the oppositely charged electrode. This concentrates the ions at the electrode and reduces the concentration of ions in the water. When the electrode volume is exhausted, the water flow must be stopped and the capacitor discharged, in which case the ions are rejected back into the now concentrated solution.

European Patent Application Publication 1348670 U.S. Patent No. 5,779,891 US Patent Application Publication No. 2005/103634 U.S. Patent Application Publication No. 2004/130851 U.S. Patent Application Publication No. 2002/154469 U.S. Pat. No. 6,309,532 International Publication No. 2007/070594 Pamphlet WO 2007/087274 pamphlet

  It would be desirable to have a desalination device or system that differs from currently available devices or systems. It would also be desirable to have a method of making or using an apparatus or system for desalting that is different from currently available methods.

  According to an embodiment, a method is provided that includes releasing a solute from a solute-bearing electrode into an outlet liquid stream, the outlet liquid stream having a relatively higher concentration of solute than the original feed stream from which the solute-loaded electrode acquired the solute. Have.

  In one embodiment, a desalting system is provided that includes a first subsystem and a second subsystem in fluid communication with the first subsystem. The second subsystem includes means for releasing the solute from the solute-carrying electrode into the draining liquid stream, the draining liquid stream being relatively higher than the original solute-bearing feed stream from which the solute-carrying electrode has acquired the solute It has a concentration of solutes.

  In one aspect, a desalting system having a first subsystem receives a feed fluid and produces first and second effluent fluid streams. The first effluent fluid stream has a solute concentration that is relatively lower than the solute concentration of the feed fluid. The second effluent fluid stream has a solute concentration relatively higher than the solute concentration of the feed fluid.

  In one embodiment, a processing system is provided that includes a first subsystem, a second subsystem in fluid communication with the first subsystem, and a controller in communication with the second subsystem. In response to the signal from the controller, the second subsystem releases the solute from the solute-carrying electrode into the draining liquid stream. The effluent liquid stream has a relatively higher concentration of solute than the original solute-bearing feed stream from which the solute-bearing electrode has acquired that solute.

  In one aspect, the first subsystem receives the feed liquid and produces a first flow and a second flow. Compared to the feed liquid, the first stream has a lower solute content and the second stream has a higher solute content. This second stream flows into the second subsystem as a solute-bearing feed stream.

Like numbers refer to substantially the same parts throughout the drawings.
FIG. 1 is a conceptual view of an apparatus according to an embodiment of the present invention. 2 is an exploded perspective view of a portion of the stack of FIG. 1; FIG. 3 is a conceptual view of another apparatus according to an embodiment of the present invention. FIG. 4 is a perspective view of a charged supercapacitor deionization cell in accordance with some embodiments of the present invention. FIG. 5 is a perspective view of a working supercapacitor desalting cell in a discharged state according to some embodiments of the present invention. FIG. 6 is a block diagram of a desalination system in accordance with some embodiments of the present invention. FIG. 7 is a block diagram of a test setup in accordance with an embodiment of the present invention. FIG. 8 is a graphical representation of the test results obtained in the first representative experiment of the test setup in FIG. FIG. 9 is a graphical representation of the test results obtained in the first representative experiment of the test setup in FIG. FIG. 10 is a graphical representation of the test results obtained in the first representative experiment of the test setup in FIG. FIG. 11 is a graphical representation of the test results obtained in the second representative experiment of the test setup in FIG. FIG. 12 is a graphical representation of the test results obtained in the second representative experiment of the test setup in FIG. FIG. 13 is a block diagram of a desalination system for wastewater management. FIG. 14 is a block diagram of another embodiment of a desalination system for the management of wastewater. FIG. 15 is a block diagram of another embodiment of a desalination system for the management of wastewater.

  Embodiments of the present invention relate to the field of liquid desalting. Embodiments of the present invention relate to methods of using a demineralizer.

  A supercapacitor desalination (SCD) cell according to embodiments of the present invention may be used for desalination of seawater or other demineralization of brackish water to reduce the amount of salt to levels acceptable for home and industrial applications. it can. Such SCD cells can remove other charged or ionic impurities from the liquid or reduce such impurities.

  The general language, as used throughout the specification and claims, applies to the modification of quantitative indications that can vary within an acceptable range without causing a change in the associated basic function obtain. Thus, values modified by terms such as "about" are not limited to the exact values specified. In some instances, the rough language may correspond to the accuracy of the instrument that measures that value.

  Supercapacitors are electrochemical capacitors that have relatively high energy density when compared to common capacitors. As used herein, supercapacitors include other high performance capacitors such as ultracapacitors. A capacitor is an electrical device capable of storing energy in an electric field between a pair of closely spaced conductors (referred to as "plates"). When a voltage is applied to the capacitors, charges of equal but opposite polarity accumulate on each plate. Saturated water refers to water saturated with one or more solutes or salts at a given temperature. As used herein, supersaturated water refers to water that contains, at a given temperature, one or more solutes or salts in an amount above the solubility limit of the solute or salt. Scaling refers to the concentration or precipitation that otherwise accumulates on the side wall in contact with the salt or solute carrying liquid with the salt or solute in solution.

  FIG. 1 is a schematic diagram of a representative supercapacitor desalination device 10 having a controller (not shown) and using a desalination vessel 12. The desalting vessel has an inner surface defining a volume. The desalination vessel contains the supercapacitor desalination stack 14 in this volume. The desalination stack comprises a plurality of supercapacitor desalination cells 16. Each of the plurality of cells 16 includes a pair of electrodes, an insulating spacer, and a pair of current collectors. In addition, the desalination vessel comprises at least one inlet 18 through which the feed liquid enters the desalination vessel, and an outlet 20 through which the supercapacitor desalination cell and the liquid exit the desalination vessel. The liquid can be guided into the demineralization vessel using an external force. Suitable external forces include gravity, suction and pumps.

  The salinity of the liquid leaving the desalination vessel through the outlet is different from the salinity of the feed liquid entering the desalination vessel through the inlet. The difference in salinity depends on whether the cell is in the charge mode of operation (removing salt or other impurities from the feed liquid stream) or in the discharge mode of operation (salt or other impurities are added to the feed liquid stream) Can be higher or lower. The controller can be coupled to appropriate valves, sensors, switches, etc. and controlled such that the mode of operation can be reversibly switched from the charge mode to the discharge mode in response to predetermined criteria. Such criteria include elapsed time, saturation, conductivity, resistance, and the like.

  The feed liquid may be passed through the stack one or more times during the charging phase. That is, two or more iterations may be required to deionize the liquid until the charged species are at a predetermined level as measured by an appropriately positioned sensor in communication with the controller. In some embodiments, a plurality of such cells can be placed in the desalting vessel so that the product of one cell can be treated as a feed liquid to another cell. In this way, it is possible to pass the liquid several times through the deionization cell before exiting through the outlet.

  The desalting vessel may be made of any suitable desalting vessel material. Suitable desalination container materials include one or more materials selected from metal or plastic. Suitable metals include precious metals and iron based alloys such as stainless steel. Suitable plastics include thermosetting materials such as acrylics, urethanes, epoxies, and thermoplastic materials such as polycarbonates, polyvinyl chloride (PVC) and polyolefins. Suitable polyolefins include polyethylene or polypropylene. As will be apparent, the choice of the material of the desalting vessel ensures that the material of the desalting vessel does not contribute to the impurities of the liquid to be deionised or desalted. The desalting vessel may be cylindrical in shape. Furthermore, the demineralization vessel may be shaped to converge at the inlet and outlet as shown in FIG. Other shapes and sizes may be used for the desalting vessel.

  Referring to FIG. 2, an arrangement of various elements used in a supercapacitor desalination stack, such as stack 14 of FIG. 1, is shown. In the illustrated embodiment, the supercapacitor desalting stack includes a plurality of supercapacitor desalting cells and a plurality of current collectors.

  The supercapacitor desalination cell comprises at least one pair of electrodes. Each electrode pair includes a first electrode, a second electrode and an electrically insulating spacer disposed therebetween. In some embodiments, in the charge mode of operation of the stack, the first and second electrodes can adsorb ions from the liquid to be deionized. In this charging mode of operation, the surfaces of the first and second electrodes can each store a charge or a polarized potential. The potential of the first electrode can be different than the potential of the second electrode. Thereafter, as the liquid flows through the electrodes, the charge stored on the electrodes attracts the oppositely charged ions from the liquid, which adsorbs the charged ions onto the surface of the electrode. After the electrode surface is saturated with the adsorbed charged ions, the operating mode of the stack can be switched from the charging operating mode to the discharging operating mode.

  The charged ions can be removed or desorbed from the surface of the electrode by discharging the cell. In the discharge mode of operation, the adsorbed ions can leave the surfaces of the first and second electrodes and join with the liquid flowing through the cell during the discharge mode of operation. In some embodiments, the polarity of the electrodes may be reversed during the discharge mode of operation of the cell. In other embodiments, the polarity of the first and second electrodes may be the same as one another during the discharge mode of operation of the cell. The charging and discharging of this cell will be described and illustrated in more detail with reference to FIGS. 4 and 5.

  In some embodiments, the first electrodes may each include a first conductive material, and the second electrodes may each include a different second conductive material. As used herein, the term conductive material refers to a material that is conductive regardless of thermal conductivity. In these embodiments, the first conductive material and the second conductive material may comprise a conductive material, such as a conductive polymer composite. In some embodiments, the first conductive material and the second conductive material can have particles with smaller size and larger surface area. Due to the large surface area, such conductive materials can allow the cell to have high adsorption capacity, high energy density and high capacitance. The stack capacitance can be greater than about 10 F / g. In one embodiment, the stack capacitance is about 10 to about 50 F / g, about 50 to about 75 F / g, about 75 to about 100 F / g, about 100 to about 150 F / g, about 150 to about 250 F / g, about 250 ~ About 400 F / g, about 400 to about 500 F / g, about 500 to about 750 F / g, about 750 to about 800 F / g, or more than about 80 F / g.

  Suitable first and second electrically conductive materials can be formed as particles having an average particle size of less than about 500 μm. Furthermore, these particles may be present with a monomodal particle distribution of about one. In another embodiment, the particle size distribution is a multimodal distribution, such as a bimodal distribution. The use of multimodal particle size distribution allows for packing throughout the particle bed and ultimately control of flow and surface area. Of course, the first conductive material and the second conductive material may differ from each other in surface area, configuration, porosity and composition. In representative embodiments, the particle size of the first conductive material and the second conductive material is in the range of about 5 to about 10 μm, about 10 to about 30 μm, about 30 to about 60 μm, or about 60 to about 100 μm. It is.

In addition, the first and second conductive materials can have high porosity. In one embodiment, the porosity of the first and / or second material is in the range of about 10 to about 95% of theoretical density. Each electrode may have a relatively high Brunauer-Emmet-Teller (BET) surface area. Relatively high BET surface area ranges from about 2.0 to about 5.5 × ¹⁰ 6 ftz ^{lb -l} or about 400~1100m ² g ^-1. In one embodiment, the surface area of the electrode is in the range of about 1.3 × 10 ⁷ ftz lb ⁻¹ or less or less than about 2600 m ² g ⁻¹ . Each electrode may have a relatively low electrical resistance (eg, <40 mS ² cm). In one embodiment, additional materials may be attached to the surfaces of the first and second electrodes, such additional materials including catalysts, antifouling agents, surface energy modifiers and the like.

Furthermore, the first conductive material and the second conductive material may comprise an organic or inorganic material, for example, these conductive materials may comprise a polymer, or a conductive inorganic composite May be included. In another exemplary embodiment, the inorganic conductive material includes carbon, metal or metal oxide. Furthermore, the first and second electrodes may be formed of the same material as each other, or may contain or contain the same material. Alternatively, the first and second conductive electrodes may use different materials, or the arrangement or amount of the same material may be different. Additionally, in some embodiments, the first conductive material and the second conductive material may be reversibly doped. In these embodiments, the first and second materials may or may not be the same. In representative embodiments, the dopant includes an anion or a cation. Nonlimiting examples of cations include Li ⁺ , Na ⁺ , K ⁺ , NH ₄ ⁺ , Mg ²⁺ , Ca ²⁺ , Zn ²⁺ , Fe ²⁺ , Al ³⁺ , or combinations thereof. Nonlimiting examples of suitable anions include Cl ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ and PO ₄ ³⁻ .

  Suitable conductive polymers may include one or more of polypyrrole, polythiophene, or polyaniline. In some embodiments, the conductive polymer includes polypyrrole, polythiophene, or polyaniline sulfone, chloride, fluoride, alkyl, or phenyl derivatives. In one embodiment, the conductive material includes carbon or a carbon-based material. Suitable carbon-based materials include activated carbon particles, porous carbon particles, carbon fibers, carbon nanotubes and carbon aerogels. Materials suitable for use in the first and second conductive composites include carbides of titanium, zirconium, vanadium, tantalum, tungsten and niobium. Other materials suitable for use in the first conductive composite and the second conductive composite include oxides of manganese and iron. In an exemplary embodiment, the conductive material includes a powder having a nanoscale particle size. Suitable nanoscale powders include ferritic materials.

  In addition, conductive fillers can also be used with the conductive material. Suitable adhesives, curing agents or catalysts may also be used with the conductive material. The filler or additive is the minimum width of the conductive material, viscosity, curing profile, adhesion, electrical properties, chemical resistance (eg moisture resistance, solvent resistance), glass transition, thermal conductivity, heat deflection temperature Etc can affect one or more attributes.

  The filler may have an average particle size of less than about 500 μm. In one embodiment, the filler is about 1 to about 5 nm, about 5 to about 10 nm, about 10 to about 50 nm, about 50 to about 100 nm, about 100 to about 1000 nm, about 1 to about 50 μm, about 50 to about 100 μm, It may have an average particle size in the range of about 100 to about 250 μm, about 250 to about 500 μm, or greater than about 500 nm.

  In some embodiments, the filler particles may have a shape and size that may be selected based on application specific criteria. Suitable shapes include one or more of spherical particles, hemispherical particles, rods, fibers, geometric shapes, and the like. These particles may be hollow or solid or porous. Long particles such as rods and fibers can have different lengths and lengths.

  In embodiments where a conductive polymer is used as the conductive material, the capacitance of the cell can be increased due to the reversible induced current mechanism or the electron transfer mechanism of the polymer. In an exemplary embodiment, the capacitance of the cell may increase by about 3 to about 5 times. Such capacitance values are higher than those of cells such as cells using activated carbon materials. In some embodiments, the capacitance of cells using conductive polymer composites ranges from about 100 to about 800 F / g. Because of this high capacitance value, the first and second electrodes each do not require high operating pressure or electrochemical reaction, thereby adsorbing a significant amount of ions onto their respective surfaces. Energy consumption can be relatively low compared to systems using desalination techniques.

  The high surface area of the conductive polymer can facilitate the deposition of relatively large amounts of ions, so that devices with similar efficiencies can have relatively smaller footprints or sizes. As used herein, “footprint” refers to the number of supercapacitor desalination cells used in a given stack, or superseded during design to achieve a given productivity. The number of capacitor desalting stacks. In some embodiments, the footprint of a supercapacitor desalination device having a stack of 200 may exceed one supercapacitor desalination cell. In one embodiment, the footprint of a supercapacitor desalination device having a stack of 200 is less than 1000 supercapacitor desalination cells. In one embodiment, the footprint may range from about 1 to about 10 supercapacitor desalting cells, about 10 to about 100 supercapacitor desalting cells, or about 100 to about 500 supercapacitor desalting cells.

  In the illustrated embodiment the first and second electrodes are arranged parallel to one another in the form of a plate forming a stacked structure, but in other embodiments the first and second electrodes have different shapes You may have. Such other shapes include barbed and nested wedge configurations. In one embodiment, the first and second electrodes may be arranged concentrically in roll form with respect to each other.

  Suitable electrically insulating spacers include electrically insulating polymers. Suitable electrically insulating polymers include olefinic materials. Suitable olefinic materials may include polyethylene and polypropylene, which may be halogenated. Other suitable electrically insulating polymers include, for example, polyvinyl chloride, polytetrafluoroethylene, polysulfones, polyarylene ethers and nylons. Furthermore, the insulating spacer can have a thickness in the range of about 0.0000001 to about 1 cm. In one embodiment, the thickness is in the range of about 0.0000100 to about 0.00010 cm, about 0.00010 to about 0.010 cm, about 0.0010 to about 0.1 cm, or about 0.10 to about 1 cm. is there. The electrically insulating spacer is in the form of a membrane, a mesh, a mat, a sheet, a film or a weave. The electrically insulating spacer may be porous, perforated or have fluid channels extending from one surface to another to allow fluid communication. These fluid channels, holes and holes can have an average diameter of less than 5 mm and can be configured to increase the disturbance of the fluid flowing therethrough. In one embodiment, the average diameter ranges from about 5 to about 4 mm, about 4 to about 3 mm, about 3 to about 2 mm, about 2 to about 1 mm, about 1 to about 0.5 mm, or less than about 0.5 mm. . Such increased disturbance can have a positive effect on the performance of the adjacent electrode. In one embodiment, a mesh is used that has overlapping yarns that are not coplanar. These out-of-plane yarns can increase the disturbance of the fluid flowing therethrough.

  Further, as shown, each cell may include a current collector 30 coupled to the first and second electrodes. The current collector conducts electrons. The choice of current collector material and operating parameters can affect the power consumption and lifetime of the cell. For example, high contact resistance between one of the electrodes and the corresponding current collector can result in high power consumption. In some embodiments, the conductive materials of the first and second electrodes of the cell can be deposited on corresponding current collectors. In such embodiments, the conductive material of the electrode can be deposited on the current collector surface by one or more deposition techniques. Suitable deposition techniques include sputtering, thermal spraying, spin coating, printing, dipping and other painting.

  Suitable current collectors can be formed as a foil or a mesh. The current collector may include a conductive material. Suitable conductive materials include one or more of aluminum, copper, nickel, titanium, platinum and palladium. Other suitable conductive materials include one or both of iridium or rhodium, or an iridium alloy or a rhodium alloy. In one embodiment, the current collector may be a titanium mesh. In one embodiment, the current collector may have a core metal and another metal disposed on its surface. In another embodiment, the current collector comprises carbon paper / felt or a conductive carbon composite.

  The stack may further include a support plate 32 that provides mechanical stability to the structure. Suitable support plates may comprise one or more materials selected from metal or plastic. Suitable metals include precious metals and iron based alloys such as stainless steel. Suitable plastics include thermosetting materials such as acrylics, urethanes, epoxies, and thermoplastic materials such as polycarbonates, polyvinyl chloride (PVC) and polyolefins. Suitable polyolefins include polyethylene or polypropylene.

  The support plate may function as an electrical contact with the stack to provide electrical communication between the stack and the power source or energy recovery converter. In the illustrated embodiment, the support plate, the electrodes and the current collector may direct the flow of liquid and define holes or holes 21 defining fluid flow paths between the electrode pairs. As shown in the figure, liquid is directed into the cell from the direction indicated by the arrow indicating the direction labeled 22. After entering the cell, the liquid contacts and is directed to flow along the surface of the corresponding electrode, as indicated by the fluid flow path indicated by the directional arrow with reference numeral 23. The liquid can flow as it traverses through the largest part of the surface of the corresponding electrode. If the residence time, ie the contact time of the liquid with the electrode surface, is long, more adsorption of charged species or ions from the liquid to the electrode surface may occur. That is, the longer the contact time between the liquid and the surface of the electrode, the less the number of repetitions may be required to reduce the concentration of charged species in the liquid to a predetermined value. The liquid then exits the cell as indicated by the arrow indicating the direction labeled 25.

  Although the stack of FIG. 2 has been described in connection with incorporation into a demineralization vessel, in alternate embodiments, the stack can also be used without the use of a desalting vessel. For example, as shown in FIG. 3, a stack containing cells may be sandwiched between support plates without the use of a desalting vessel. The stacks can be held together by applying mechanical force to the support plates. As mentioned above, each cell includes electrodes separated by insulating spacers. Additionally, a current collector is coupled to the first and second electrodes. According to the embodiment of FIG. 3, the inlets and outlets are aligned with the openings in the support plate so that liquid can flow through the stack as described in connection with FIG.

  As a comparative example, a conventional SCD system is operated alternately in the charging and discharging steps. In this conventional system, the feed water in the charge and discharge steps is supplied from the same water source. During the charge mode of operation, the feed water is supplied to the SCD system to remove salts or other impurities from the feed stream. Thus, the product of the SCD system (i.e., the "dilution stream") in the charge mode of operation is less salty than the feed stream. During the discharge mode of operation where salts or other impurities are removed from the SCD cell, salts and impurities are released into the incoming feed stream from the SCD cell, and thus the product in the discharge mode of operation (eg "concentrated flow") Is more salty than the feed stream. This concentrated stream is more saline than the feed stream and can therefore be considered as waste water to be discarded.

  The embodiment of the present invention works in contrast to the above comparative example. A zero fluid discharge (ZLD) SCD system is provided having a clear mode of operation. The principles of the disclosed ZLD-SCD will be described with reference to FIGS. According to an embodiment of the present invention, saturated or supersaturated water is supplied to the supercapacitor desalination device during the discharge step, but normal feed water is supplied to the supercapacitor desalination device during the charge step. The water may or may not contain other salts which may be saturated or supersaturated in addition to the salt. In addition to this salt, the water may or may not contain other salts which may be saturated or supersaturated.

  In some embodiments, saturated or supersaturated water (concentrated stream) is continuously circulated and reused in the discharge step. Thus, the degree of supersaturation of the concentrate stream constantly increases as the discharge continues. As a result, the degree of saturation increases until precipitation begins to occur. If the precipitation rate in the discharge step is equal to the salt removal rate in the charge step, the degree of supersaturation of the concentrate stream will not increase further and equilibrium will be established. Advantageously, according to the described system, the volume of effluent does not increase with the number of cycles, so the liquid drainage of the system is zero or nearly zero. The ZLD-SCD system advantageously provides advantages over typical water treatment systems by reducing or eliminating the amount of liquid waste.

  Referring briefly to FIG. 4, a representative SCD cell 16 is shown in charge mode of operation. As previously described, SCD cell 16 typically includes electrodes 24 and 26. These electrodes 24 and 26 are electrically connected to a power supply (not shown) and oppositely charged. The power source can act as an energy recovery converter or can be in operative connection with the energy converter. Thus, during the charge mode of operation, the cell 16 stores energy. In the illustrated embodiment, the electrode 24 is coupled to the negative terminal of the power supply and functions as a negative electrode. Similarly, electrode 26 is connected to the positive terminal of the power supply and functions as a positive electrode. Insulating spacers may be disposed between the oppositely charged electrodes as already described and described in connection with FIG. During the charging mode of operation, a feed stream 34 with charged species is fed into the SCD cell. As the feed stream 34 passes between the electrodes, charged species or ions from the feed liquid stream are accumulated on the electrodes. As shown, cations 36 move towards the negative electrode and anions 38 move towards the positive electrode. As a result of this charge accumulation inside the cell, the dilution stream 40 (output liquid) leaving the cell has a lower concentration of charged species as compared to the feed liquid flow into the cell.

  As mentioned above, in some embodiments, deionization may be provided again by feeding the dilution stream to another similar cell or feeding it back to the same cell as the feed stream. In some embodiments, multiple such cells may be used in one stack, as described above. Also, the system may include several stacks. In this case, the dilution stream can be fed to another type of demineralizer, such as a reverse osmosis unit (not shown) for further processing.

  During charging of the SCD cell, charged species (anions and cations) derived from the feed stream are accumulated on the surface of the corresponding oppositely charged electrode, as described and described in connection with FIG. . The accumulation of charged species on the electrode continues until the cell is discharged, the saturation limit is reached, or the resistance of the ion layer is approximately the same as the potential of the electrode.

  FIG. 5 shows the cell in the discharge mode of operation. During the discharge mode of operation, the cell releases stored energy captured during the charge mode of operation. The charged species desorb from the electrode surface. And, instead of using the same feed stream during charge and discharge modes of operation, the amount of liquid discharge that must be eliminated by feeding different feed streams into the cell from different sources during the discharge mode of operation. It can be reduced. Specifically, a saturated feed stream 42 is provided to the cell during the discharge mode of operation. That is, in the illustrated embodiment, in the discharge operation mode of the cell, positive ions and negative ions are desorbed from the electrode surface and discharged from the cell together with the saturated feed flow, and thereafter recirculated to each discharge operation mode and repeated. Produces an exhaust stream 44 that can be regenerated. During the discharge mode of operation, the liquid (exhaust stream 44) leaving the supercapacitor desalination cell has a higher ion concentration compared to the saturated feed stream 42 supplied to the supercapacitor desalination cell. The exhaust stream 44 may be more saturated than the saturated feed stream and may be supersaturated.

  As noted above, when the supercapacitor desalination mode of operation transitions from the charge mode of operation to the discharge mode of operation, in this system, when the battery transitions from the fully charged mode of operation to the discharged mode of operation. There is energy release similar to energy release. In some embodiments, it may be desirable to obtain this energy for use. The desalting system may include an energy recovery device such as a converter (not shown). Thus, the cell may also be in communication with the energy recovery device.

  In the charge mode of operation, the converter directs the supply power from the power supply, such as a battery (not shown) or from the distribution grid, to the cell. Conversely, in the discharge mode of operation, the converter re-directs or recovers the electrical energy emitted by the cell. This redirected or recovered energy can be at least partially transferred to an energy storage device, such as a battery, or to a grid. For example, the energy recovered from this cell can be used later in charging the cell, a cell different from the stack of cells, or by cells of the different stack. This energy recovery converter can be referred to as a bi-directional converter since there are two directions of energy flow through the converter. For example, energy can flow from the stack to the grid or bus, or from the grid or bus to the stack. In some embodiments, the converter recovers the energy of the cell discharging in the discharge mode of operation in DC form and later transfers it to the cell in DC form to charge the cell and charge it from the discharge state Can be converted to

  Referring again to FIG. 5, a saturated feed stream may be supplied to the cell from a regeneration source such as regeneration tank 46. As shown, during the discharge mode of operation, the regeneration vessel can define a feedback loop. The feedback loop can provide a saturated feed stream to the cell and can accept an exhaust stream from the cell. As the same stream is recirculated through the cell during each discharge step, the feed and discharge streams become progressively saturated as the discharge step continues. Finally, the recycled liquid, also referred to herein as "regenerated water" or "regenerated liquid", saturates so that precipitation begins to occur and solid precipitate 48 begins to form. The precipitate can be filtered to remain in the regeneration tank. The precipitate can be removed from the regeneration tank when the cell is not discharged. For example, the system may also include a crystal separation unit to remove the precipitate. Suitable separation units include centrifuges, filtration membranes, bleed-off valves, skimmers, filtration units or evaporation units. The method of removing this solid or semi-solid slurry can result in zero or nearly zero liquid waste in the disclosed system. If the precipitation rate in the discharge step is equal to the salt removal rate in the charge step, the degree of supersaturation of the concentrate stream will not increase and equilibrium may be established. According to the described system, the volume of effluent does not seem to increase with the number of cycles, so the liquid drainage of the system is zero or nearly zero. When precipitation occurs in the discharge regeneration tank, the cells used in the SCD system can be operated in combination with a crystallizer or vessel acting as a crystallizer to promote crystallization due to supersaturation, for which Further described below.

  The described system can be operated using the same reclaimed water indefinitely during the discharge cycle, so that there is no need to discard liquid waste. However, when the flow is changed from regenerated water (discharge mode of operation) to normal feed water (charge mode of operation), some of the regenerated water retained in the SCD cell during the discharge mode of operation mixes into the feed stream during the charge mode of operation. It can. This action can have an adverse effect on desalting. The magnitude of this harmful "mixing effect" depends on the concentration difference between the reclaimed water and the feed stream, as well as the volume of reclaimed water retained in the cell. For example, if the feed stream contains sparingly soluble salts, the concentration of salts dissolved in the reclaimed water will not be high for continuous precipitation (in the range of about 0.1 to about 10000 ppm). In this case, there is no limit to the possible reuse time of the reclaimed water. However, if the feed stream contains a soluble salt, such as sodium chloride, the concentration of the dissolved salt in the regenerating water can be very high (in the range of about 20000 to about 200,000 ppm), and for the desalting process The disadvantages of mixing can be considerable. In this case, if the reclaimed water is reused continuously from cycle to cycle, the concentration of reclaimed water can increase to the point where the penalty of mixing action becomes equal to the demineralization capacity in the charging step, and then there will be a net withdrawal in subsequent charging cycles. Salt capacity is reduced or lost.

  Several approaches may be taken to eliminate or reduce the disadvantages of mixing effects. One approach is stepwise or continuous so as to change the flow of liquid entering the supercapacitor demineralizer at a certain time interval (eg, 10-30 seconds) before changing the flow out of the supercapacitor desalinizer. It is to use the flow shift. This approach may allow a portion of the reclaimed water retained in the cell to be pushed out to the regeneration tank at the end of the discharge step, thereby reducing the disadvantages associated with the mixing action. Another approach to reduce mixing effects is to pump and hold air and other gases into the supercapacitor desalinizer prior to reintroducing the feed stream to the supercapacitor desalinizer during the charge mode of operation. Water as much as possible. This approach can also reduce the disadvantages associated with mixing. Yet another approach is to use feed water flushing. For example, at the end of the discharge step, the outlet of the supercapacitor desalinizer is shifted to the output of the liquid product in the charge mode of operation for its intended target (eg, for storage of desalted / usable water) Before putting it into the dilution tank), some amount of feed stream can be used to flush the supercapacitor demineralizer. The water used to flush the supercapacitor desalination unit may instead be directed to a regeneration tank or another vessel. Using this approach, it may be necessary to remove some of the reclaimed water from the regeneration tank in order to maintain a constant volume of reclaimed water used during discharge. The tradeoff of the flushing approach during this cycle would be that some loss of water recovery could occur. Furthermore, these approaches may be used in any combination. For example, an air-flushing step could be used following flushing with some feed water.

  Another consideration of the disclosed system is "scaling". High concentrations of salts or solutes dissolved in the regenerating liquid (e.g., saturated feed and discharge streams) can increase the scaling potential. In one embodiment, the supercapacitor desalinizers are alternately charged and discharged, and the supercapacitor desalinizers (and thus the individual cells) are alternately exposed to both the normal feed stream and the highly saturated feed stream. Reduced intermittent exposure of the supercapacitor desalination device to saturated feed stream reduces the scaling potential compared to the scaling potential in the RO system as compared to the RO system where the concentrate stream always flows through the concentrate spacer during operation Do.

The described SCD system can provide reduced scaling as compared to the EDR system. Similar to the SCD desalting process, the EDR chamber is alternately exposed to diluent and concentrate. However, one of the leading causes of scaling in EDR system, a local pH changes due to polarization in the dilution chamber, resulting OH ^- migrates to the concentration chamber through the anionic membrane, wherein the anion It is well known that this is the fact that the concentration of both ions and cations is very high and precipitation first occurs under certain conditions. Clearly, in the SCD process, there is no polarization during the discharge step and no local pH changes occur, thus reducing the risk of scaling.

  The supercapacitor desalination device may have dilution and concentration vessels alternating with one another. The concentration of dilution water limits the operating current during operation in the EDR system. In contrast, in supercapacitor desalinizers, the concentration of dilution water only limits the operating current during the charging process. This feature makes the operation of the supercapacitor demineralizer relatively more flexible than the EDR system. For example, in supercapacitor demineralizers, a lower operating current can be used for longer charge times during the charging process to avoid polarization, but higher operating currents are used during the shorter discharging process. This relationship can be used while maintaining the same power for one cycle, so the risk of scaling can be reduced by less polarization and less exposure time to high concentration liquids.

  Referring now to FIG. 6, a block diagram of an SCD system 50 in accordance with a representative embodiment of the present invention is shown. As noted above, the SCD system 50 includes an SCD unit 52 that includes one or more SCD cells arranged in a stacked configuration. During the charge mode of operation, a feed stream 54 is directed via valve 58 to the inlet 56 of the SCD unit 52. As mentioned above, feed stream 54 passes through SCD unit 52 for deionization. Deionized dilution stream 60 is directed through valve 64 through outlet 62 of SCD unit 52 to the intended target. For example, dilution stream 60 may be directed to a dilution tank (not shown) for use. Alternatively, the dilution stream may be fed back into the SCD system as a feed stream for further processing, or the dilution stream may be directed to a different desalination system such as an RO system for further processing. Good. As mentioned above, the dilution stream is less salty than the feed stream.

  During the discharge mode of operation, a saturated feed stream 66 is provided to the inlet 56 of the SCD unit 52. This saturated feed stream 66 is provided by regeneration tank 68 via valve 70 and valve 58. As mentioned above, the regeneration vessel 68 contains a saturated or supersaturated liquid which is used during the discharge mode of operation. The saturated feed stream 66 is directed through the SCD unit 52 to the outlet 62 where it is returned to the regeneration tank 68 as a discharge stream 72 via a valve 64. As noted above, the effluent stream is more salty than the saturated feed stream. If the precipitation rate in the discharge step is equal to the salt removal rate in the charge step, the degree of supersaturation of the concentrate stream circulating the regeneration tank and the SCD unit is not further increased and equilibrium is established. Because the volume of effluent does not have to increase with the number of cycles, the system may have zero or nearly zero liquid emissions. In any event, most waste is solid waste that can be removed via waste outlet 74 in the regeneration tank.

  While the above system is sufficient for most applications, the system may optionally include an evaporator 78 and / or a crystallizer 80 to provide 100% water recovery. As shown in FIG. 6, both the evaporator 78 and the crystallizer 80 may be used, or only one may be used, or both in a single evaporation and thermal crystallization system. It may be combined. In accordance with the illustrated embodiment, at the end of each discharge cycle, a constant amount of feed stream is fed into the SCD unit via a valve. The output stream passes through the outlet and is led into the regeneration tank via a valve. In order to maintain a constant volume in the regeneration tank, a corresponding amount of liquid in the regeneration tank may be fed into the evaporator via a valve and a flow path. This liquid can be very highly concentrated (e.g. 10 to 30 wt%) after evaporation in the evaporator and can then be fed to the crystallizer via a flow path. The crystallizer is a thermal crystallizer, for example a drier. The crystallizer produces solid waste 84 which can be discarded by conventional means.

  The control of each valve 58, 64 and 70 may be preset and / or controlled by an external controller (not shown) to provide the proper function of the system to control the flow of liquid by the system. obtain. Furthermore, in another embodiment, the SCD unit is provided with a plurality of inlets and outlets, each source of liquid flowing into the SCD unit having a respective inlet path, and each of the liquid flowing out of the SCD unit The desired location of may have its own exit path. Furthermore, although not described, other mechanisms such as pumps can be used to withdraw water to / from the SCD unit or to other components of the system.

  The following examples are included to provide those skilled in the art with additional guidance in the practice of the present invention, and accordingly these examples are intended to limit the invention as defined in the claims. is not.

Example 1
A test system 86 as shown in FIG. 7 is used. The system 86 includes an SCD unit 88, a dilution tank 90 and a regeneration tank 92. The dilution tank 90 is used to provide a feed liquid stream to the SCD unit 88 during the charge mode of operation. A pump 94 is used to pump supply liquid to the SCD unit 88 during the charge mode of operation. A regeneration tank 92 is used to provide a feed liquid flow to the SCD unit 88 during the discharge mode of operation. The pump 96 is used to pump the feed liquid through the SCD unit 88 during the discharge mode of operation.

Perform the first experiment using CaSO ₄ water. Since CaSO ₄ is considered to be the most noteworthy inorganic salt whose precipitation is a major obstacle to membrane processes (eg RO systems) operating at higher recovery rates, nearly saturated CaSO ₄ solution (2025 ppm, 96. 3% saturation) is used for both the charge mode of operation (feed stream) and the discharge mode of operation (saturated feed stream). The volume of water to be filled is 2000 ml and the volume of regenerated water is 250 ml. The process is carried out in batch mode (i.e., recycle and reuse both fill water and reclaim water in a continuous cycle with a flow rate of about 100 ml / min).

  The experiment is performed using a single cell SCD unit (88). The electrode with an effective area of 16 cm × 32 cm consisted of activated carbon and titanium mesh for the active substance and the current collector, respectively. A 0.95 mm thick plastic mesh spacer is placed between the two electrodes. Anion exchange and cation membranes are placed between the electrodes and on both sides of the spacer to block counter ions and increase current efficiency. An electrochemical device, here a battery test system, is connected to the two electrodes of the cell, with the anion membrane surface as the positive electrode and the cationic membrane surface as the negative electrode. Suitable battery test systems are described by Kingnuo Electricic, Inc. It is commercially available from (Wuhan, China).

  Four ball valves 98, 100, 102 and 104 are installed at the inlet and outlet of SCD unit 88 to control the flow into and out of SCD unit 88, as shown in FIG. Needle valves 106 and 108 are also used to more accurately control the flow of fluid through system 86. The timing of charge and discharge is controlled by the electrochemical device. In the experiments described, each cycle included a 10 minute constant current (600 mA) charging step followed by a 1 minute rest step. After a one minute rest step, the cycle was followed by a 10 minute constant current (-600 mA) discharge step followed by another one minute rest step. Then repeat this cycle.

  In the charging step, the ball valve 98 and the ball valve 102 are opened, and the ball valve 100 and the ball valve 104 are closed, whereby the filling water in the dilution tank 90 is circulated through the SCD unit 88. In the discharge process, the ball valves 98 and 102 are closed by reversing the open / close states of the ball valves 98, 100, 102 and 104, the ball valves 100 and 104 are opened, and the regenerated water in the regeneration tank 92 is an SCD unit. Circulate through 88. The air is pumped to the SCD unit 88 in each pause step to minimize unwanted mixing of the charge water and the regeneration water in changing the flow between the charge step and the discharge step, from the previous step. Minimize the water retained in the cell. As mentioned above, each cycle took about 22 minutes (10 minutes of charging, 10 minutes of discharging and two 1 minute pauses). More than 30 cycles are carried out continuously to study the desalting of the packed water and the increase in the conductivity of the regenerated water, as well as the crystallization and mixing action.

  During the experiments described herein, the conductivity of the charge water is monitored at the end of each charging step. FIG. 8 shows the change in concentration in the filling water for 30 cycles. The resulting salt concentration is shown along axis 110 in units of parts per million (ppm), while the cycle is shown along axis 112. As shown in the salt concentration tracking curve 114, the concentration of the packed water decreased with each cycle, resulting in the concentration decreasing from 2000 ppm to about 500 ppm after 30 cycles. It also tracks the net salt removal in grams (g) in each cycle, as shown along axis 116. As shown in the best fit salt removal curve 118, the amount of salt removed in each cycle is distributed in a relatively narrow range (about 0.07 to 0.16 g), especially in the latter experiment There is. Thus, the salt removal capacity of SCD unit 88 showed no deterioration over the 30 cycles performed.

  The change in the conductivity of the reclaimed water over 30 cycles is shown in FIG. The graph shows the measured conductivity (mS / cm) at axis 120 and the calculated percent saturation at axis 122 for each cycle shown on axis 124. Obviously, the conductivity is a measure of the amount of salt dissolved in the water, and the percentage of supersaturation of the reclaimed water can be calculated from this. As shown in the conductivity plot 126, the conductivity of the reclaimed water increased rapidly in the first few cycles, but the supersaturation level of the reclaimed water was relatively low as shown in the saturation plot 128. However, as the level of supersaturation increases, the rate of precipitation of salt at higher supersaturation increases while the rate of increase in conductivity decreases because the same amount of dissolved salt is released to the concentrate stream at each discharge step.

  As shown in FIG. 9, at the end of the 10th and 30th cycles, there are two sharp drops in the conductivity of the discharge step, which represent two long pauses in the experiment. (Each about 12 hours a night and 64 hours a weekend). As shown in the figure, a significant amount of salt crystallized out of the supersaturated water during this long rest period, resulting in a reduction in the concentration of dissolved salt. This crystallization is described in more detail below. However, it is worth noting that the electrical conductivity of the reclaimed water decreases slowly if the reclaimed water is paused, even during a short period of time, for example during the charging process time. In one example, the conductivity of the reclaimed water dropped from 7.69 mS / cm to 7.67 mS / cm after standing for 8 minutes. This indicates that precipitation has occurred at all times, including the charge, discharge and rest steps.

As mentioned above, the degree of supersaturation of the reclaimed water increased as the number of cycles increased. At the end of the tenth cycle, some particles are observed at the bottom of the regeneration tank 92. After two hours of rest, the sediment at the bottom of the regeneration tank 92 has increased significantly. After resting for 12 hours (overnight), the amount of precipitation increased further while the conductivity of the regenerated water decreased. The volume of the precipitate is analyzed using the results of a scanning electron microscope (SEM). Analysis by X-ray diffraction confirmed that this precipitate was CaSO ₄ .

  Another interesting phenomenon that is observed is that the material used to construct the regeneration vessel 92 appears to have an effect on the crystallization process. The regeneration tank 92 is defined by two cylindrical columns and retains the regeneration water in the experiment. The first column is a 250 ml glass cylinder, which is used for the 30 cycle test described above. After 30 cycles, the reclaimed water is transferred to another column made of polymeric material (PMMA). The same reclaimed water is used to further circulate through the 10 cycle polymer column. FIG. 10 shows a graph comparing the change in conductivity of the reclaimed water in a glass column during a series of cycles with a polymer column. The conductivity (mS / cm) is shown along the y-axis 132 and the number of cycles is shown along the x-axis 134. As shown, the conductivity of the reclaimed water in the polymer column increases more rapidly compared to the glass column. This is illustrated by the conductivity plot 136 (organic glass) compared to the conductivity plot 130 (glass). Crystallization appears to be difficult with polymer columns, and using this type of material to construct a regeneration tank can affect the efficiency of the system. The glass surface may be more polar than the polymer surface, which favors nucleation of inorganic salts.

  Different materials are used in the regeneration tank 92 and the piping. In one embodiment, the regeneration vessel 92 can be elongated with first and second ends, and each end can be constructed of different materials. In use, the first end can be above or on top of the second end and the second end is on the bottom or bottom. A first type of material is used at the first end of the regeneration vessel 92. Another type of material is used at the second end of the regeneration vessel 92.

  The crystallization zone of the regeneration tank is the lower region of the regeneration tank, where the crystallization particles collect and sink. Suitable build materials include, for example, inorganic compositions as a structure or as a coating covering the inner surface of a regenerative water tank. Suitable construction materials include ceramics, metals and glasses. The polymeric material could be used as the material of the clarification zone of the container. In this zone clear saturated or supersaturated water is supplied to the SCD unit. Suitable polymeric materials may be engineering plastics. The use of a coating or liner would allow one to construct a regeneration tank using a single material and post-treat the inner surface with another material.

Example 2
As shown in the figure, the degree of supersaturation of the reclaimed water can be as high as about 600% (see FIG. 9). Although the SCD process exhibits good tolerance to supersaturation of the reclaimed water, lower saturation levels may be beneficial, with lower mixing penalties and less risk of scaling. Sand is put into the regeneration tank to prove this. The height of the sand in the regeneration column is about 25 cm. The sand is sieved to a particle size ranging from about 1 mm to about 3 mm. The sieved sand is washed several times with deionized water before it is put into the column. During the discharge step, effluent water is pumped from the bottom of the column and pumped to the inlet of the SCD unit. The regeneration stream from the outlet of the SCD unit is returned to the top of the regeneration tank.

  FIG. 11 shows the conductivity (y-axis 140) versus cycle (x-axis 142) profile of both the dilution stream 144 from the charge cycle and the concentrate stream 146 during the discharge cycle. FIG. 11 shows that the conductivity of the dilution stream 144 drops during the cycle, with the exception of the spike at the end of cycle 20, where the original feed water is replaced with another new tank There is. The conductivity of the concentrate stream 146 shows a relatively sharp increase in the first few cycles, but tends to be constant during the subsequent cycles. Two drops (cycle 10 and cycle 16 are for a long rest step. The first drop is for a 45 minute rest step and the second drop is for a 12 hour rest step. These trends are: Very similar to the trend that can be observed in experiments without a bed of sand Precipitation can be observed at the top of the bed of sand in a regeneration column.

  When comparing the degree of supersaturation of the reclaimed water with and without sand in the reclaim column, the difference is significant, as shown in FIG. FIG. 12 shows the conductivity of the concentrate stream (y-axis 148) vs. cycle (x-axis 150) with and without sand in the regeneration tank. In both cases, the conductivity of the reclaimed water tends to be constant with increasing number of cycles, but the absolute degree of supersaturation of the reclaimed water is different in these two cases (with and without sand). Specifically, when sand is present in the regeneration vessel as shown by plot 154, a much lower equilibrium conductivity can be observed than when sand is not placed in the regeneration vessel shown by plot 152. The mechanism of this phenomenon may be that sand provides many seeding sites. The seed sites promote precipitation in the regenerated water. Another function of the sand bed is to act as a filtration bed for the reclaimed water. Because of the high degree of supersaturation, many small crystals may be suspended in the regenerating water, which is filtered by sand prior to entering the SCD unit during the discharge step. Besides sand beds, other crystallization enhancement techniques include forced precipitation, seed crystal enhancement, magnetic field enhancement, chemical precipitation, pH control, anti-scalant control, and the like.

Example 3
The above experiments (Examples 1 and 2) are performed using CaSO ₄ water. In Example 3, synthetic water at twice the concentration of Los Angeles tap water is made and tested. The composition of this synthetic water is shown in Table 1.

  The water used in Example 3 is hard and can be considered as concentrated in an RO plant treating LA water, for example with a water recovery of 50%. Prior to experimentation, make an automated test system with solenoid valves for automatic switches. During the experiment, the volumes of filling water and regeneration water are 4500 ml (ml) and 200 ml respectively. The test results are similar to the results of the previously described experiments in terms of conductivity profiles for feed water and reclaimed water. Small settling particles can be observed in the sand bed. The difference is that the conductivity of the regenerated water continues to increase to about 16 mS / cm, whereas in the experiment with calcium sulfate water it becomes constant at less than about 10 mS / cm. This effect may be attributed to the presence of soluble salts such as sodium chloride. At times, the presence of soluble salts may be less desirable for this process due to mixing effects, which show a gradually decreasing desalting capacity during the cycle.

  Referring to FIG. 13, demineralization system 160 includes a first subsystem 162 and a second subsystem 164. Each of these subsystems may be a water treatment system. The first subsystem 162 may be a reverse osmosis system and the second subsystem may be a supercapacitor desalination system. In one embodiment, the second subsystem may be a ZLD-SCD system. Further, the first subsystem may be located within the processing plant and the second subsystem may be located remotely from the processing plant.

  The first subsystem receives the feed stream 166 (inflow) to be desalinated or processed, and exits the two streams. The first subsystem produces a first dilution stream 168 with solids that are dissolved or suspended relatively lower than the feed stream. This dilution stream can be used, for example, for human consumption. The first subsystem produces a second concentrated stream 170 (rich in salinity) with relatively more dissolved or suspended solids than the feed stream. This concentrated stream is referred to as the output stream or wastewater. If the first subsystem 162 is a treatment plant and the second subsystem 164 is located remotely, the second subsystem is otherwise considered waste water from the treatment plant (requires disposal) Can be processed.

  The second subsystem 164 may receive the concentrate stream exiting the first subsystem and desalt or otherwise treat the concentrate stream. The second subsystem 164 may include the SCD or ZLD-SCD system. The second subsystem 164 produces two effluent streams. Dilution stream 172 has a relatively lower concentration of dissolved or suspended solids (less salinity) than the concentrate stream. This dilution stream may, for example, be available for human consumption. The second subsystem also produces a waste stream or discharge stream 174. The effluent stream may be liquid waste, such as a concentrate stream having a higher salinity than the concentrate stream. Alternatively, in the case of the ZLD-SCD system, the effluent stream can be slurry, semi-solid, or solid waste or almost solid waste. For example, the second subsystem may have a relative volume of less than 10% of the concentrated flow volume (about 90% of the concentrated flow is desalted and converted to a diluted flow). Also, the second subsystem may be less than 1% waste of the concentrate stream (99% of the concentrate stream is desalted and converted to a dilution stream). Some or all of the dilution stream may be returned to the first subsystem via feedback path 176 for further processing.

  Referring now to FIG. 14, a demineralization system 160 is provided that includes a first subsystem 162 and a second subsystem 164. In the illustrated embodiment, the first subsystem includes a two-pass brackish water reverse osmosis (RO) system having a first RO unit 178 and a second RO unit 180. The first and second RO units together define the RO system of the desalination plant. The feed stream 166 entering the first RO unit 178 produces two effluent streams, a clean dilution stream 168 and a concentrated substream 182. The dilution stream 168 can be consumed or used for clean water end-use applications. Concentrated substream 182 can be supplied as an incoming stream to second RO unit 180 for further desalting. Similar to the first RO unit 178, the second RO unit 180 has two effluent streams, namely a clean dilution stream (also designated by reference numeral 168) that can be consumed or used for clean water applications. A concentrated stream (also indicated by reference numeral 170) is produced. In some treatment plants or treatment systems, concentrate stream 170 is waste water that must be further treated.

  The first subsystem may be a two pass RO system and may be coupled in series with the second subsystem 164 to receive the concentrate stream 170 from the processing plant. In the illustrated embodiment, the second subsystem 164 includes a zero liquid discharge-supercapacitor desalination (ZLD-SCD) system. The ZLD-SCD system includes an SCD unit 184 and a regeneration tank 186, which can be used to manage the concentrate stream 170. The SCD unit and the regeneration unit are arranged in a feedback configuration so that the exhaust stream (concentrated or super-enriched form) circulates between the SCD unit and the regeneration tank when the SCD unit is in the discharge mode of operation. The second subsystem contains an SCD unit that does not have a regeneration tank. In this alternative embodiment, the waste 174 may contain relatively more liquid than when using a regeneration tank.

  In the desalting system 160 of FIG. 14, the water recovery rate is increased beyond that of a system incorporating only a two-pass RO system. For example, an RO plant incorporating a two-pass RO system with 75% water recovery rate and a concentration control SCD unit with 90% water recovery rate is 1- (1-0.75) × (1 in all systems) -0.90) = 97.5% water recovery rate. Relatively increased water recovery may be beneficial to the operation of the desalination plant. According to one embodiment, the RO unit may be part of a desalination plant or another system, in which case the wastewater product of RO unit (concentrated stream 170) is a second sub-unit comprising a SCD unit or a ZLD-SCD unit. Supplied to the system. Thus, the ZLD-SCD unit of the second subsystem can be used to manage the wastewater from the established treatment plant.

  In the illustrated desalination system, the RO concentrate is partially recovered as product water (diluted stream), and the flow rate of feed stream 166 can be reduced accordingly. Due to the reduction in the flow rate of the feed stream, the actual retentate (retentate stream 170) treated in the second subsystem 164 is also reduced. Assuming that the cost of capital is proportional to the flow rate of the feed stream, there may be an economic benefit of the RO system as compared to the original two-pass RO system.

  In another embodiment illustrated in FIG. 15, the dilution stream 172 of the second subsystem 164 is fed back to the first subsystem 162 for further desalting. That is, the dilution stream 172 may be further desalted in the first subsystem 162, instead of using or consuming the dilution stream 172 for tap water. The dilution stream generated from the SCD unit is returned as an input to the second RO unit 180 when the SCD unit is in the charge mode of operation. In this embodiment, it is possible to further process the dilution stream. Furthermore, this embodiment reduces the need for storage or disposal of clean water in the second subsystem. In this operating configuration, the first subsystem is a water treatment and tap water production plant, and the second subsystem can process concentrate water instead of having to manage the tap water (dilution flow) that can be generated. It may be useful when managing. After processing in the first subsystem, the second dilution stream 172 may be used as clean water with the first dilution stream 168.

  The embodiments described herein are examples of compositions, structures, systems and methods having elements corresponding to the elements of the invention recited in the claims. This description will enable one of ordinary skill in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the invention recited in the claims. Accordingly, the scope of the present invention includes compositions, structures, systems and methods that do not differ from the terms of the claims, and further that other structures, systems and systems that do not substantially differ from the terms of the claims. Methods are included. Although only certain features and embodiments have been illustrated and described herein, many modifications and variations will be apparent to those skilled in the art. The claims cover all such modifications and variations.

Claims (60)

Releasing the solute from the solute-carrying electrode into the discharge liquid stream, the discharge liquid stream having a relatively higher concentration of solute than the original feed stream from which the solute-carrying electrode acquired the solute. ,Method. The electrode is a supercapacitor electrode, and further comprising absorbing solutes from the feed stream onto the electrode to form a solute-loaded electrode and an output stream, the output stream being relatively lower in solute concentration than the feed stream The method of claim 1, comprising: The electrode is disposed in the second demineralizer and further comprising flowing the feed stream from the first demineralizer to the second demineralizer, or the electrode is in the second demineralizer 3. The method of claim 2, further comprising: flowing the output stream from the second demineralizer to the first demineralizer. The first demineralizer includes a membrane and a liquid stream is flowed through the membrane to form a feed stream or an output stream is flowed from the second demineralizer through the membrane to filter the output stream The method according to claim 3, comprising. 4. The method of claim 3, wherein the first desalting device comprises a dialysis device or a reverse osmosis device. 6. The method of claim 5, wherein the dialysis device is an electrodialysis desalting or electrodialysis desalting device. Further, the method includes generating a concentrate stream and a dilution stream in the first demineralizer, the concentrate stream having a higher concentration of solutes than the dilution stream, and the concentrate stream flowing out of the first demineralizer is second 4. The method of claim 3, wherein said feed stream is to a demineralizer of 8. The method of claim 7, wherein the volume of the concentrate stream is greater than about 80% of the volume of the effluent liquid stream. The combined volume of the first demineralizer dilution stream and the second demineralizer output stream is greater than about 97.5% of the volume of the total inflow of liquid into the first demineralizer. Item 7. The method according to Item 7. The method according to claim 1, further comprising circulating the discharge liquid stream such that the flow flows through the electrode more than once before leaving the housing containing the electrode. The method of claim 1, further comprising storing energy in the electrode in a first mode of operation and recovering energy from the electrode in a second mode of operation. The method of claim 1, wherein the electrode is a positively charged electrode and the solute is negatively charged. The method of claim 1, wherein the releasing comprises supersaturating the effluent liquid stream. The method of claim 1, further comprising reducing the amount of water in the effluent liquid stream. 15. The method of claim 14, wherein the reducing comprises forming a solid, semi-solid or slurry material from the effluent liquid stream to separate solutes and forming a recovered water stream having a lower solute concentration than the effluent liquid stream. 16. The method of claim 15, further comprising pressing a solid, semi-solid or slurry material. 15. The method of claim 14, wherein the reducing comprises evaporating the effluent liquid stream to separate the solute from the recovered water stream having a lower solute concentration than the effluent liquid stream. 15. The method of claim 14, wherein the reducing comprises precipitating or crystallizing the effluent liquid stream to separate the solute from the recovered water stream having a lower solute concentration than the effluent liquid stream. A desalting system comprising a first subsystem and a second subsystem in fluid communication with the first subsystem, the second subsystem releasing solutes from the solute-carrying electrode into the discharge liquid stream Said desalting system comprising: means for causing the discharge liquid stream to have a relatively higher concentration of solute than the solute-loaded feed stream from which the solute-loaded electrode acquired the solute. The first subsystem receives the feed fluid and produces first and second effluent fluid streams, the first effluent fluid stream having a solute concentration relatively lower than the solute concentration of the feed fluid, and the second 20. The desalination system of claim 19, wherein the effluent fluid stream of has a solute concentration that is relatively higher than the solute concentration of the feed fluid. 20. The desalting system of claim 19, wherein the first subsystem comprises a reverse osmosis system, an electrodialysis desalting system, an electrodialysis desalting system or a nanofiltration desalting system. The second subsystem has a charge operation mode and a discharge operation mode, and the second subsystem
A regeneration source for supplying an exhaust stream to the supercapacitor desalination unit when the supercapacitor desalination unit is in the second discharge operating mode, and a first one when the supercapacitor desalination unit is in the first charge operating mode 20. The desalination system of claim 19, comprising a supercapacitor desalination unit that receives a second effluent fluid stream from the subsystem. 23. The desalination system of claim 22, wherein the regeneration source receives an exhaust stream from a supercapacitor desalination unit when the supercapacitor desalination unit is in a second discharge mode of operation. The supercapacitor desalination unit produces an output stream when the supercapacitor desalination unit is in a charging mode of operation, the output stream having a relatively lower concentration of solute than the second effluent fluid stream. 23. The desalination system according to 23. The first subsystem receives at least a portion of the output flow from the supercapacitor desalination unit to define a fluid loop, and the output flow portion received is at least a portion of the feed fluid to the first subsystem. 22. The desalination system according to 22. 23. The desalination system of claim 22, wherein the first subsystem is located in the water treatment plant and the second subsystem is located outside the water treatment plant. First subsystem,
A processing system comprising a second subsystem in fluid communication with a first subsystem, and a controller connected with the second subsystem, the second subsystem being responsive to signals from the controller. A treatment system for releasing solutes from a solute-carrying electrode into an effluent liquid stream, the effluent liquid stream having a relatively higher concentration of solute than the solute-carrying feed stream from which the solute-loaded electrode acquired the solute. A first subsystem receives the feed liquid and produces a first stream having a lower solute content than the feed liquid and a second stream having a higher solute content than the feed liquid, the second stream being a solute 28. The system of claim 27, flowing to the second subsystem as a carrier feed stream. Super capacitor desalination unit operable in charge and discharge operating modes,
A source configured to supply a feed stream to the supercapacitor desalination unit when the supercapacitor desalination unit is in the charge mode of operation, and a supercapacitor desalination when the supercapacitor desalination unit is in the discharge mode of operation A desalination system comprising a regeneration source configured to supply a saturated or supersaturated feed stream to the unit. 30. The desalination system of claim 29, wherein the regeneration source is configured to receive an exhaust stream from a supercapacitor desalination unit. 30. The desalting system of claim 29, wherein the regeneration source comprises a saturated liquid. 30. The desalting system of claim 29, wherein the regeneration source comprises a supersaturated liquid. The regeneration source is elongated and has a first end and a second end, wherein the first end of the regeneration source defines a clearing zone for holding a saturated or supersaturated liquid. 30. The desalting system of claim 29, wherein the second end of the regeneration vessel defines a crystallization zone for holding crystallized particles. The regeneration source comprises a first material and a different second material, the first material being disposed at a first end and the second material being disposed at a second end 34. The desalting system of claim 33. 35. The desalination system of claim 34, wherein the first material comprises an organic material and the second material comprises an inorganic material. 30. The desalination system of claim 29, wherein less than 20% of the liquid supplied to the supercapacitor desalination unit by the source and regeneration source is liquid waste. 37. The desalination system of claim 36, wherein less than 10% of the liquid supplied to the supercapacitor desalination unit by the source and regeneration source is liquid waste. 30. The desalting system of claim 29, further comprising a controller. The controller is operable to control the desalination system such that sequential step-wise or continuous flow shifting switches the flow of liquid to the SCD unit before a certain time interval that changes the outflow from the SCD unit 39. The desalting system of claim 38, wherein: 39. The desalination system of claim 38, wherein the controller is operable to switch the mode of operation of the desalination system from a discharge mode of operation to a charge mode of operation and from a charge mode of operation to a discharge mode of operation. 30. The desalination system of claim 29, further configured to pump air through the supercapacitor desalination unit between the charge mode of operation and the discharge mode of operation. 30. The desalination system of claim 29, further comprising a crystallizer operable to crystallize the effluent from the supercapacitor desalination unit. 43. The desalting system of claim 42, wherein the crystallizer comprises a dryer. 30. The desalting system of claim 29, wherein the regeneration source comprises sand. 30. The desalting system of claim 29, further comprising an evaporator operable to vaporize liquid waste in the system. 30. The desalination system of claim 29, wherein the supercapacitor desalination unit comprises a stack of supercapacitor desalination cells. The supercapacitor desalination unit is
A first electrode comprising a first conductive material, the first electrode being capable of adsorbing ions in a charge mode of operation of the cell and desorbing ions in a discharge mode of operation of the cell;
A second electrode comprising a second conductive material, the second electrode being capable of adsorbing ions in a charge mode of operation of the cell and capable of desorbing ions in a discharge mode of operation of the cell;
A spacer disposed between the first and second electrodes, the spacer electrically isolates the first electrode from the second electrode,
30. The desalting system of claim 29, comprising a first current collector coupled to the first electrode, and a second current collector coupled to the second electrode. 48. The desalting system of claim 47, wherein at least one of the first electrode and the second electrode has a surface area per volume of greater than about 400 m < ² > / g. Super capacitor desalination unit,
A first fluid flow path including a first feedback loop configured to direct fluid through the supercapacitor desalination unit when the system is in the first mode of operation, and the system is in the second mode of operation A desalting system comprising a second liquid flow path comprising a second feedback loop configured to guide the liquid through the supercapacitor desalting unit. 50. The desalination system of claim 49, wherein the first mode of operation comprises a charge mode of operation of the supercapacitor desalination unit and the second mode of operation comprises a discharge mode of operation of the supercapacitor desalination unit. 50. The desalination system of claim 49, wherein the first liquid flow path comprises a dilution tank configured to supply the feed stream to the supercapacitor desalination unit during the first mode of operation. 52. Desalination according to claim 51, wherein the supercapacitor desalination unit is configured to desalinate the feedstream from the dilution tank as it passes through the supercapacitor desalination unit during the first mode of operation. system. The second liquid flow path includes a regeneration tank configured to supply a saturated or supersaturated feed stream to the supercapacitor desalination unit during the second mode of operation and to receive an outlet stream from the supercapacitor desalination unit. 50. The desalting system of claim 49. The supercapacitor desalination unit is configured to salinate the saturated or supersaturated feedstream from the regeneration tank when the saturated or supersaturated feedstream passes the supercapacitor desalination unit during the second mode of operation. 53. The desalination system according to 53. Supplying a first liquid stream from the first source through the supercapacitor desalination unit during the first period of time charge operation mode;
A liquid processing method comprising supplying a second liquid stream from a second source through a supercapacitor desalination unit during a second period of time discharge operating mode. 56. The liquid treatment method of claim 55, wherein providing the first liquid stream comprises desalting the first liquid stream as it passes through the supercapacitor desalination unit. 56. The liquid treatment method of claim 55, wherein providing the second liquid stream comprises chlorinating the second liquid stream as it passes through the supercapacitor desalination unit. 56. The liquid treatment method according to claim 55, wherein the time of the first period is longer than the time of the second period. 56. The liquid treatment method of claim 55, wherein providing the second stream of liquid from the second source comprises providing saturated or supersaturated liquid from the regeneration tank through the supercapacitor desalination unit. 56. The liquid treatment method of claim 55, wherein providing the second liquid stream comprises providing a finite amount of liquid from the regeneration vessel in a feedback loop comprising a supercapacitor desalination unit and a regeneration vessel.