KR101632685B1 - Hybrid system for accomplishing selectively electrodialysis reversal and reverse electrodialysis - Google Patents

Abstract

It is an object of the present invention to provide a hybrid system capable of selectively performing an electrodialysis (EDR) process and a reverse electrodialysis (RED) process through control of system components in a single system. A hybrid system for performing desalination and salinity differential generation according to the present invention comprises a hybrid cell in which electrodialysis and reverse electrodialysis are performed, a controller for setting the hybrid cell in an electrodialysis operation mode or a reverse electrodialysis operation mode, Wherein the hybrid cell is connected to the power supply unit when the control unit is set to the electrodialysis operation mode and the hybrid cell is connected to the power supply unit when the control unit is set to the reverse electrodialysis operation mode, And the like.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a hybrid system that selectively performs desalination and salinity generation. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a hybrid system for selectively performing desalination and salinity generation, and more particularly, to a hybrid system for selectively desalting and salting out electricity by converting desalting by electrodialysis (EDR) and salinity generation by reverse electrodialysis (RED) . ≪ / RTI >

Electrodialysis Reversal (EDR) refers to a device that separates ions in a solution by arranging a cation exchange membrane and anion exchange membrane alternately between positive and negative electrodes and by electrical force. The electrodialysis device can remove or concentrate ions, and is mainly used for seawater desalination, wastewater reuse, plating wastewater, and recovery of valuable metals and concentration and desalination of a specific salt. It is used for purifying pure water, adjusting the sour taste of juice, It is also used to

On the other hand, reversing electrodialysis to generate electrical energy is called Reverse Electrodialysis (RED). Reverse electrodialysis is the recovery of the salinity difference energy generated in the mixing process of two fluids with different concentrations, for example, seawater and fresh water, in the form of electric energy. This energy recovery technique using the difference of the concentration of seawater and fresh water can be divided into the osmotic method and the reverse electrodialysis (RED) method originally proposed by Prof. Sidney Loeb of Israel in 1975. Currently, statkraft (WETSUS) and the Center for Sustainable Hydropower Technology in the Netherlands.

Various research reports and papers refer to a salinity generation system using reverse electrodialysis (RED) as a new renewable energy source. However, it is pointed out that the retrograde electrodialysis (RED) system has a high initial investment cost, (EDR) is being used as a desalination facility in a water treatment facility such as a sewage treatment plant. However, there has not been reported a technology for converting an EDR into an energy generation system (RED).

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an electrodialysis system and an electrodialysis system capable of selectively performing an electrodialysis (EDR) process and a reverse electrodialysis (RED) And to provide a hybrid system that can be implemented.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

In order to accomplish the above object, a hybrid system for carrying out desalination and salinity differential generation according to the present invention comprises a hybrid cell in which an electrodialysis and a reverse electrodialysis process are performed, and a hybrid cell in an electrodialysis operation mode or a reverse electrodialysis operation mode Wherein the hybrid cell is connected to the power source when the control unit is set to the electrodialysis operation mode and the hybrid cell is set to the reverse electrodialysis operation mode when the control unit is set to the electrodialysis operation mode, The hybrid cell is connected to an external resistor.

The hybrid cell includes an electrode connected to the power source unit and the external resistor to generate a potential difference, at least one cation exchange membrane and an anion exchange membrane interposed between the electrodes, a spacer interposed between the cation exchange membrane and the anion exchange membrane, , An electrode solution filled between the electrode and the cation exchange membrane, and a space between the electrode and the anion exchange membrane.

The hybrid cell may further include a first flow path connected from the hybrid cell to the brine storage and the nose reservoir, a second flow path extending from the hybrid cell to the concentrated brine reservoir, and a second flow path extending from the hybrid cell to the fresh water storage Wherein when the control unit is set to the electrodialysis mode, fluid is supplied to the hybrid cell through the first flow path, and fluid is supplied from the hybrid cell through the second flow path and the third flow path, Fluid is discharged from the hybrid cell through the first flow path, and fluid is supplied to the hybrid cell through the second flow path and the third flow path, respectively, when the control section is set to the reverse electrodialysis mode.

It is preferable that the external resistor is a variable resistor and has the same resistance value as the hybrid cell. When the control unit is set to the electrodialysis operation mode, the electrode solution is a buffer solution. When the control unit is set to the reverse electrodialysis operation mode, the electrode solution is mixed with redox-couple Solution (redox-couple solution).

The cation exchange membrane and the anion exchange membrane are repeatedly positioned to increase the efficiency of the hybrid cell. When the mode is set to the electrodialysis operation mode, the controller changes the voltage application polarity from the power source unit to the hybrid cell to 2 to 4 times per hour to remove ions attached to the electrodes. Further, the hybrid cell is composed of a single module, and can be replaced during maintenance.

According to the present invention, fresh water is produced through an electrodialysis (EDR) process, and the produced fresh water is stored, and energy can be produced through a reverse electrodialysis (RED) process if necessary. Therefore, a reverse electrodialysis (RED) system with low initial investment cost can be constructed using the existing electrodialysis (EDR) system.

In addition, by constructing the electrodialysis system and the reverse electrodialysis system as a single system, it is possible to effectively secure desalination in an environment where it is difficult to acquire fresh water from the island and the ship, and at the same time, Can be produced.

In addition, the system of the present invention can be miniaturized and used as a military distress kit when manufactured in a portable manner.

1 is a configuration diagram in an electrodialysis (EDR) operation mode of an electrodialysis and reverse electrodialysis hybrid system according to the present invention,
2 is a configuration diagram of an electrodialysis and reverse electrodialysis hybrid system according to the present invention in a reverse electrodialysis (RED) operation mode.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view for explaining an electrodialysis (EDR) operation mode in an electrodialysis and reverse electrodialysis hybrid system according to the present invention, and FIG. 2 is a view for explaining a reverse electrodialysis (RED) operation mode. The configuration and operation of the hybrid system according to the present invention will be described in detail with reference to FIGS. 1 and 2. FIG.

The hybrid system according to the present invention includes a hybrid cell 300 in which electrodialysis (EDR) and reverse electrodialysis (RED) processes are performed, a controller 300 for setting the hybrid cell 300 in an electrodialysis operation mode or a reverse electrodialysis operation mode, And a power supply unit 100 for supplying power to the hybrid cell 300. [

The hybrid cell 300 includes an electrode 330 connected to the power source unit 100 and the external resistor 400 to generate a potential difference and at least one cation exchange membrane 310 and an anion exchange membrane (Not shown), an electrode 330, a cation exchange membrane 310 or an electrode 330 and an anion exchange membrane (not shown) interposed between the electrode 330 and the cation exchange membrane 310 and the anion exchange membrane 320 And the electrode solution 340 flowing in the space 331 between the electrodes 331 and 320.

The cation exchange membrane and the anion exchange membrane are repeatedly positioned so that the water is passed through the electrode and the membrane so that a current flows between the electrode and the membrane. This water is called an electrode solution 340, and the space between these is referred to as an electrode chamber 331. When the control unit is set to the electrodialysis operation mode, the electrode solution may be a buffer solution (e.g. Na ₂ SO ₄ ).

The electrodialysis (EDR) process will be described with reference to FIG. 1, when the control unit 200 is set to the EDR operation mode, the second switch 102 is opened and the first switch 101 is closed so that the hybrid cell 300 is connected to the power source unit 100 do. When electric power is applied to both electrodes 330 from the power source unit 100, a difference in electromotive force is generated between the electrodes 330, so that the ions move in the solution in the hybrid cell 300. On the other hand, the moving negative ions pass through the anion exchange membrane 320 during the movement to the anode but do not pass through the cation exchange membrane 310. Conversely, the positive ions pass through the cation exchange membrane 310 during the movement to the cathode but do not pass through the anion exchange membrane 320 And a portion where ions are removed and a portion where ions are concentrated are formed, which are referred to as a dilution chamber 350 and a concentration chamber 360, respectively. Therefore, fresh water can be produced by desalination by applying electricity to the cell 300 through the power supply unit 100 during the EDR operation.

The following describes the flow of fluid through the hybrid cell 300 of the present invention. 1 and 2, the system of the present invention includes a first flow path 610 connected from the hybrid cell 300 to the brine storage and the nose storage, and a second flow path 610 connected from the hybrid cell 300 to the concentrated brine storage A second flow path 620, and a third flow path 630 connected from the hybrid cell 300 to the fresh water storage.

1, when the control unit is set to the electrodialysis mode, fluid (sea water) is supplied to the hybrid cell 300 through the first flow path 610, and after the desalination process is performed in the hybrid cell, (Fresh water) is discharged from the hybrid cell 300 through the third flow path 630 through the second flow path 620, respectively. The second channel 620 and the third channel 630 are provided with a bypass line parallel to the pumps 212 and 213 at the ends of the storage units 520 and 530 so that concentrated brine and fresh water Storage is possible.

The concentrated brine produced through the electrodialysis (EDR) process is stored in the concentrated saline solution storage unit 520 and the stored concentrated saline solution and fresh water are converted into the reverse electrodialysis (RED) process It is used as raw water necessary for power generation.

However, the problem of such an electrodialysis device is contamination of the ion exchange membrane, and this contamination not only lowers the efficiency of the apparatus but also shortens the lifetime of the membrane. That is, in the case of the membrane surface adjacent to the concentration chamber 360, the concentration thereof becomes maximum due to the ions migrated from the dilution chamber 350. As a result, the concentration of the surface of the concentrating chamber reaches a saturated solution, and hydroxides are formed by the migrated calcium ions (Ca 2+) and magnesium ions (Mg 2+), resulting in scale on the membrane surface and the cathode surface.

This phenomenon not only lowers the ion movement but also increases the film resistance, which generates heat and reduces the current efficiency, thus leading to a deterioration of the efficiency of the device. In order to solve such a problem, in the present invention, when the control unit is set to the electrodialysis operation mode, the voltage application polarity from the power source unit to the hybrid cell 300 is changed to a cycle of 2 to 4 times per hour.

The following is a description of the reverse electrodialysis (RED) process of the system according to the present invention with reference to FIG. Since the reverse electrodialysis (RED) system is not much different from the EDR system, it is possible to develop a hybrid system combining the two systems through control of system components.

When the control unit is set to the reverse electrodialysis (RED) mode, the first switch is opened so that the hybrid cell 300 is disconnected from the power source unit, and the second switch is closed, so that the electrode of the hybrid cell 300 is connected to the external resistor 400, Lt; / RTI > The external resistor 400 can be increased to maximize the output of the system by applying a resistance having the same resistance value as that of the hybrid cell 300 as a variable resistor.

The electrode solution is used to prevent corrosion of the electrode during EDR operation and is used to convert chemical energy into electrical energy during reverse electrodialysis (RED) operation. The electrode solution can be used in accordance with the operating conditions. For example, buffer solution (eg, Na ₂ SO ₄ ) that can prevent corrosion of the electrode while increasing the current efficiency is used in the EDR operation, It is preferable to use a redox-couple solution (for example, Fe ²⁺ / Fe ³⁺ ) to increase the efficiency. The electrode solution can be replaced at the electrode part when the electrodialysis (EDR) and the reverse electrodialysis (RED) operation are switched, and the electrode solution can be operated without replacing the electrode solution at a low output range.

As shown in FIG. 2, the fluid flows into the hybrid cell 300 through the second flow path 620 and the third flow path 630, as opposed to the EDR mode, And the fluid is discharged from the hybrid cell 300 through the first flow path 610. The stored concentrated brine and fresh water can be used as influent water during power generation by reverse electrodialysis (RED) and flow into the hybrid cell (300) through branched pipes connected to the pumps (212, 213) The effluents are mixed and stored in the nacelle reservoir through the first flow path and reusable during electrodialysis (EDR) operation.

The fresh water reservoir can be connected to an external stormwater collection system to provide additional fresh water in the summer when rainfall is concentrated. In case of increase in power demand during the summer season, the secured freshwater can be used as a fresh water supply source for reverse electrodialysis (RED) operation .

A three-way valve (201) is installed at the tip of the brine and nose reservoir to connect to the salt water storage tank during EDR operation and to the nose reservoir tank during reverse electrodialysis (RED) operation. This is possible.

In the system of the present invention, a control unit 200 (Control Device) capable of adjusting the control valves 201, 202 and 203, the pumps 211, 212 and 213 and the switches 101 and 102 and the like are disposed, and the electrodialysis (EDR) Each component is controlled collectively according to the operation conversion. In addition, the system of the present invention is capable of controlling the operation of a power source, a variable resistor, a switch, a control valve and a pump by a central control device (not shown) The concentration and temperature of the effluent influent can be measured and the concentration and temperature of the power and influent influent can be measured and controlled automatically during the reverse electrodialysis (RED) operation. In addition, the hybrid cell 300 is composed of a single module and can be replaced during maintenance.

Meanwhile, as an embodiment of the present invention, other devices such as a cell can be miniaturized and manufactured for portable use. These portable devices can be utilized as military kits for isolated soldiers during operations, or as relief goods in refugee areas.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

100: power supply unit 101: first switch
102: second switch 200:
201: first adjustment valve (three way valve) 202: second adjustment valve
203: third adjustment valve 211: first pump
212: second pump 213: third pump
300: Hybrid cell 310: Cation exchange membrane
320: anion exchange membrane 330: electrode
331: electrode chamber 340: electrode solution
350: Dilution chamber 360: Concentration chamber
400: external resistance 500: brine storage part
510: nose store 520: concentrated brine store
530: fresh water storage section 610: first flow path
620: Second Euro 630: Third Euro

Claims (8)

In a hybrid system for selectively performing desalination and salinity generation,
A hybrid cell in which an electrodialysis and a reverse electrodialysis process are selectively performed,
A controller for setting the hybrid cell to an electrodialysis operation mode or a reverse electrodialysis operation mode;
A power supply unit for supplying power to the hybrid cell;
≪ / RTI &
Wherein the hybrid cell is connected to the power source when the controller is set to the electrodialysis operation mode and the hybrid cell is connected to the external resistor when the controller is set to the reverse electrodialysis operation mode,
A first flow path from the hybrid cell to the brine storage and the nose storage,
A second flow path connected from the hybrid cell to the concentrated brine storage section,
And a third flow path connected from the hybrid cell to the fresh water storage unit
Further,
Wherein when the controller is set to the electrodialysis mode, fluid is supplied to the hybrid cell through the first flow path, and fluid is discharged from the hybrid cell through the second flow path and the third flow path, respectively,
Wherein when the control unit is set to the reverse electrodialysis mode, fluid is discharged from the hybrid cell through the first flow path, and each fluid is supplied to the hybrid cell through the second flow path and the third flow path. .
The method according to claim 1,
The hybrid cell
An electrode connected to the power supply unit and the external resistor to generate a potential difference,
At least one cation exchange membrane and an anion exchange membrane interposed between the electrodes,
A spacer interposed between the cation exchange membrane and the anion exchange membrane,
An electrode solution is formed in the space between the electrode and the cation exchange membrane and between the electrode and the anion exchange membrane
The hybrid system.
delete The method according to claim 1,
Wherein the external resistor is a variable resistor and has the same resistance value as the hybrid cell.
3. The method of claim 2,
The electrode solution is replaceable,
When the control unit is set to the electrodialysis operation mode, the electrode solution is a buffer solution,
When the control unit is set to the reverse electrodialysis operation mode, the electrode solution is a redox-couple solution
And the hybrid system.
3. The method of claim 2,
Wherein the cation exchange membrane and the anion exchange membrane are repeatedly located.
The method according to claim 6,
And when the control unit is set to the electrodialysis operation mode, changes the polarity of voltage application from the power supply unit to the hybrid cell to 2 to 4 times per hour.
8. The method of claim 7,
Wherein the hybrid cell comprises a single module and is replaceable during maintenance.

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