KR101946980B1 - Submerged Reverse Electrodialysis Apparatus For Continuously Operation - Google Patents

Abstract

The present invention relates to a main body having a seawater inflow section, a fresh water supply section, a fresh water discharge section, and a seawater sucking section; A plurality of ion exchange membranes disposed within the body and having a structured surface; Wherein the plurality of ion exchange membranes have a first flow path through which the seawater flows and a second flow path through which the fresh water flows and a second flow path through which the fresh water flows, So as to form an electrodeposited electrodialysis device.

Description

TECHNICAL FIELD [0001] The present invention relates to a submerged reverse electrodialysis apparatus for continuous operation,

The present invention relates to an immersion type reverse electrodialysis device capable of preventing fouling of an ion exchange membrane from contaminants present in natural waters and performing continuous operation for a long period of time through internal cleaning according to an operation method.

A reverse electrodialysis (RED) device is a device that converts the concentration difference energy of dissolved ions into electrical energy through an electrochemical method.

In addition to reverse electrodialysis (RED), pressure retarded osmosis (PRO) and capacitive mixing methods exist in the salinity gradient power (SGP), and reverse electrodialysis (RED) It is a technology to convert the difference in silver ion concentration directly into electric energy through electrochemical reaction, so that a thermodynamic loss is not so small and a high efficiency power generation system can be constituted.

A reverse electro-dialysis apparatus generally uses gaskets and spacers at the same time to form a flow path for seawater and fresh water.

Among these gaskets, it is general to use a material having high chemical resistance to water such as silicon, PTFE, etc., and electrical conductivity should be very low.

In recent articles (Vermaas et al.), When using gaskets and spacers of up to 50 micrometers at the same time, the internal resistance of the reverse electrodialyser is reduced and high output can be obtained Was reported.

The spacer typically uses a mesh-type structure, and a material having low electrical conductivity such as polyethylene (PE), polyethylene (Nylon), or the like is used.

The spacer prevents the cation exchange membrane and the anion exchange membrane, which are disposed on both sides of the spacer, from contacting each other to prevent electrical short-circuiting in the reverse electrodialysis device, and a space between the cation exchange membrane and the anion exchange membrane And serves to secure a flow path through which inflow water can flow in the apparatus such as seawater or fresh water.

However, due to the structural characteristics of the spacer having a dense structure, a shadow effect (a phenomenon in which the contact area between the water and the ion exchange membrane is relatively decreased as the contact area between the ion exchange membrane and the spacer increases) But also restricts the flow flow by the spacer, resulting in a high pressure loss of the reverse electrodialyser.

Spacers generally have an opening (a gap between two lines that make up the weave structure, or a gap size) that decreases as the thickness becomes thinner, and a shadow effect . Thus, the use of thinner spacers results in a reduction in the space occupied by the fluid within the seawater and freshwater channels, resulting in increased pressure.

The performance of the reverse electrodialyser is generally influenced by the linear velocity of each fluid in the seawater and freshwater channel, and the higher the linear velocity of the fluid, the higher the output density.

When the pressure increases in each channel through which the seawater and the fresh water flow, the flow of the fluid flows along the original flow path, and at the same time, the property of proceeding perpendicularly to the ion exchange membrane becomes stronger and the contaminant contained in the fluid contacts with the ion exchange membrane per unit time And the number of times of collision between the contaminant and the ion exchange membrane and the spacer and the energy increase naturally increase the fouling of each material.

That is, due to the pressure loss due to the spacer, the contaminants existing in the inflow water adhere to the voids of the spacer. Such contamination not only lowers the long-term operation performance of the reverse electrodialyser, but also consumes a lot of energy to reduce, prevent or recover irreversible pollution reactions, causing serious problems in the maintenance of the reverse electrodialyser.

When the spacer is used in the reverse electrodialysis apparatus, the problem of pressure loss is very important. In particular, when the spacer starts to be contaminated, the pressure loss becomes larger, so that the energy consumption of the pump increases and consequently the energy efficiency of the system decreases.

In addition, the conventional reverse electrodialysis apparatus should install at least two pumps for the transfer of seawater and the transfer of fresh water, and the energy consumed by each pump is influenced by the hydraulic fluid discharged from the pump and discharged from the sea surface There has been a problem of consuming a lot of energy for transferring to the electrodialyser.

That is, the back electrodialysis power generation apparatus consumes 20 ~ 30% of the total power generation amount by the pump for supplying seawater and fresh water, thereby deteriorating the overall power generation efficiency.

Therefore, there is a need for a technique capable of overcoming the problems such as pressure head, membrane fouling phenomenon, and reduction in power generation efficiency due to the use of a pump, which are possessed by the retro-electrodialysis apparatus having the ion exchange membrane including the conventional spacer .

KR registration 10-1723807 (2013.03.31)

In order to solve the problems of the conventional reverse electrodialysis power generation apparatus, the present invention is intended to minimize the construction of the pump by immersing the reverse electrodialyser equipped with an ion exchange membrane having a structured surface in seawater, Which is capable of continuous operation over a long period of time by minimizing the performance degradation caused by the electrochemical reaction.

In order to achieve the above object, there is provided a water treatment system comprising: a main body having a seawater inflow section, a fresh water supply section, a fresh water discharge section and a seawater sucking section; A plurality of ion exchange membranes disposed within the body and having a structured surface; Wherein the plurality of ion exchange membranes have a first flow path through which the seawater flows and a second flow path through which the fresh water flows and a second flow path through which the fresh water flows, Thereby forming a reverse electrodialysis device.

According to the present invention, it is possible to overcome the problems such as pressure head, fouling phenomenon of the membrane, reduction of power generation efficiency by the use of a pump, and the like of the retro-electrodialysis power generator provided with the ion exchange membrane including the conventional spacer.

FIG. 1 and FIG. 2 are schematic diagrams illustrating an immersion type electrodialysis apparatus according to an embodiment of the present invention.
3 and 4 are schematic views showing an ion exchange membrane according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

In addition, the same or corresponding reference numerals are given to the same or corresponding reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. For convenience of explanation, the size and shape of each constituent member shown in the drawings are exaggerated or reduced .

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

The present invention relates to an immersion type electrodialyzed power generator (10).

The present invention relates to a method and apparatus for recovering energy required by a pump by decreasing a position head by moving a reverse electrodialysis power generation apparatus below sea level so that a reverse electrodialysis power generation apparatus has a negative value of a position head value with respect to sea level The total power generation efficiency can be increased.

In addition, the problem of biofouling and the like generated on the membrane surface by the ion exchange membrane having the structured surface provided in the reverse electrodialysis power generation device can be prevented, and the power generation efficiency can be increased.

1 and 2, the immersion type electrodialyzer 10 of the present invention includes a seawater inflow section 301, a fresh water supply section 410, a fresh water discharge section 420, and a seawater suction section 310 (Not shown).

A plurality of ion exchange membranes (100) disposed in the main body (11) and having a structured surface, and porous electrodes arranged to produce electricity by a difference in concentration of seawater and fresh water passing through the ion exchange membrane (100) The plurality of ion exchange membranes 100 may be arranged to form a first flow path 300 through which seawater flows and a second flow path 400 through which fresh water flows.

Here, the two porous electrodes may be provided in pairs.

More specifically, the first flow path 300 of the main body 11 into which the seawater flows according to the present invention is structured such that the seawater is opened to allow the flow of the pump without power.

The second flow path 400 of the main body 11 has a clogged structure that is fluidly connected to the fresh water supply flow path 410.

Here, the first channel 300 and the second channel 400 may be alternately formed between the cation exchange membrane 101 and the anion exchange membrane 102.

Further, a gasket may be provided to form a flow path between the ion exchange membranes 100.

The sea water inflow section 301 may have a structure in which at least a part of the sea water inflow section 301 is opened to allow the seawater to flow into the one surface of the main body 11 by the water pressure difference, The seawater can flow through the filter to the first flow path 300 through the seawater inflow section 301.

3 and 4, the ion exchange membrane 100 of the present invention includes a channel 200 for guiding a fluid flow on an ion exchange membrane.

More specifically, the channel 200 is formed of the same material as the ion exchange membrane 100 and includes a plurality of first members 210 arranged at predetermined intervals along the height direction of the channel 200.

The first member 210 includes a first member 210 and a second member 220. The second member 220 connects the two adjacent first members 210 and is formed of a material different from the first member 210.

The channel 200 may have a height of 10 to 100 micrometers and a width of 4 to 100 micrometers.

Here, the height of the channel 200 is more preferably 10 to 50 micrometers.

If the height of the channel 200 is more than 100 micrometers, a shear stress due to fluid may be generated and the structure may be structurally weak such as a dropout phenomenon.

In addition, in the case of the retro-electrodialysis apparatus having the ion exchange membrane 100, the movement speed of the ions is drastically reduced, and the performance of the retro-electrodialysis apparatus can be reduced.

The height of the ion exchange membrane 100 may be 10 to 100 micrometers, preferably 30 to 50 micrometers.

When the height of the ion exchange membrane 100 exceeds 100 micrometers, the electrical resistance increases due to the structural limitations of the ion exchange membrane, and the performance can be reduced.

Also, the internal resistance of the cell can be minimized when the height of the ion exchange membrane 100 is in the range of 30 to 50 micrometers.

The height of the first member 210 may be 10 to 30 micrometers.

At least one first member 210 of the channel may be provided to contact the ion exchange membrane 100.

Here, when the first member 210 is a low viscosity material, it can be stacked more.

The second member 220 may be formed of a catechol compound comprising an acrylic, vinyl, epoxy silane coupling agent and polydodamine, a polymer electrolyte to induce an electrostatic attractive force, and an adhesive comprising cyanoacrylate . ≪ / RTI >

Particularly, the polymer electrolyte includes a polymer having an electric charge opposite to that of the ion exchange membrane. For example, since the cation exchange membrane has a positive charge, the polymer electrolyte can have a negative charge, and the anion exchange membrane has a negative charge, so that the polymer electrolyte can have a positive charge.

Here, the first member 210 may be made of the same material as the material of the ion exchange membrane used in the present invention, and may be an ion exchange resin used for preparing an ion exchange membrane.

In addition, at least a portion of the first member 210 and the second member 220 may be hydrophobic.

More specifically, the first member 210 and the second member 220 include a part of the hydrophobic material such as graphene or a part of the hydrophobic functional group so that the first member 210 and the second member 220 220 can be reduced to prevent film contamination.

Meanwhile, adhesion between the ion exchange membrane 100 and the channel 200 or between the first member 210 and the second member 220 by a click reaction, an epoxy-thiol reaction, and an epoxy- .

3, the first member 210 and the second member 220 may be sequentially arranged along the height direction of the channel on the ion exchange membrane 100, and although not shown, The second member 220 and the first member 210 may be sequentially arranged along the height direction of the channel on the substrate 100.

In order to prevent the channel 200 formed as described above from being easily detached from the ion exchange membrane due to an external force such as a hydraulic pressure, the second member is structured to be anchored, that is, A compound, a polymer electrolyte, and an adhesive.

The anchoring phenomenon as described above causes the ion exchange resin to be absorbed into the ion exchange membrane 100 and at the same time maintains the constant structure in the outside and the channel 200 is removed (removed) from the ion exchange membrane 100 by water pressure .

Referring again to FIGS. 1 and 2, the ion exchange membrane 100 may be provided by alternating the cation exchange membrane 101 and the anion exchange membrane 102.

The immersion type electrodialyzed electric power generator of the present invention further includes a microfilter 600 installed to prevent the floating substances in the seawater from flowing into the plurality of first flow paths 300 provided between the ion exchange membranes 100 .

The seawater supplied to the submerged retro-electrodialysis unit 10 of the present invention is formed in the housing of the back electrodialysis unit main body 11, that is, on the outer wall thereof, (600).

In other words, seawater passing through the microfilter 600 can prevent clogging of the flow path of the ion exchange membrane provided therein, and enables long-term operation of the immersion type electrodialysis system 10.

In addition, the first flow path 300 and the seawater suction unit 310 are fluidly connected to each other, and the seawater stored in the first flow path 300 is discharged to the outside of the main body 11 through the seawater suction unit 310 And then discharged.

Here, there is an effect that the flow of seawater flowing in the first flow path 300 of the submerged electrostatic electrodeposition generator 10 can be smoothly performed by using the pump connected to the seawater suction unit 310.

That is, when the pump is not used, the flow rate in the flow path is reduced and the amount of electricity generated by the reverse electrodeposition power generation apparatus may decrease. Therefore, the seawater flow in the apparatus, i.e., the first flow path 300, .

At this time, the energy consumed by the pump used can be compensated by the pressure head of the seawater, so that it consumes very little energy compared with the pump power consumed to flow seawater into the retro-electrodialysis power plant operated on the land. .

The fresh water may be at least one of industrial wastewater discharge water treated secondarily, sewage treatment plant discharge water, and power plant discharge water.

That is, the resource recycling effect can be obtained.

Here, the fresh water supply unit 410 and the fresh water discharge unit 420 may be connected to a pump for supplying or discharging fresh water.

More specifically, the pump is used to supply fresh water to the retro-electrodialysis power generator 10 installed below the sea level. Since the position head of the retro-electrodialysis generator is smaller than the source of the fresh water, Energy is less than the energy consumed to supply freshwater to equipment operating onshore.

The reverse electrodeposition power generation apparatus 10 of the present invention may further include a brine supply unit 700 for supplying brine to the second flow path 400 in a higher concentration than sea water, .

The brine supply unit 700 may further be provided to the main body 11 so as to be fluidly connected with the second flow path 400. The brine supply unit 410 may be provided with a brine supply unit 700, .

In addition, the fresh water supply unit 410 stops the supply of fresh water, switches the supply of the fresh water, and supplies the brine to the second flow path 400 through the fresh water supply unit 410 at the brine supply unit.

More specifically, in the operation of the immersion type reverse electrodeposition generator 10 of the present invention, problems such as fouling may occur on the surface of the ion exchange membrane 100 and the porous electrode 500.

Accordingly, in order to solve this problem, in order to stop the supply of fresh water to the second flow path 400 fluidly connected to the fresh water supply unit 410 and supply the brine having a salt concentration higher than that of the sea water, And the reverse potential is generated.

Whereby the potential difference applied to the electrode can be switched.

That is, the anode is changed to the cathode and the cathode is changed to the anode, whereby contaminants can be removed from the electrode surface.

Biofouling, which can cause problems on the membrane surface, can also prevent fouling formation by injecting highly concentrated brine.

Here, the brine having a salt concentration higher than that of sea water can have a concentration of about 7 wt% or more.

In addition, the seawater sucked through the seawater suction unit 310 can produce fresh water and highly concentrated brine in connection with the desalination process.

The fresh water produced as described above can be utilized for various purposes, and the concentrated water can be supplied to the submerged electrodialyzed power generator 10 of the present invention to be utilized for operation and maintenance of the apparatus.

The porous electrode may be a porous electrode of carbon material.

More specifically, the capacitive electrode may include a porous carbon material selected from the group consisting of carbon felt, carbon cloth, activated carbon, or surface activated carbon.

The electrolyte of the storage electrode may be an aqueous solution of sodium chloride or sodium chloride (NaCl).

Here, since the storage electrode does not need to use an electrode solution containing conventional cyanide, it is possible to prevent seawater contamination due to leakage of cyanide.

The electrolyte of the accumulator electrode may be a seawater pretreated with a filter or the like.

At this time, it may be necessary to switch the applied potential for power generation, and the highly concentrated brine can be utilized to switch the applied potential.

10: Submerged reverse electrodialysis power generator 11:
100: ion exchange membrane
101: Cation exchange membrane 102: Anion exchange membrane
200: channel
210: first member 220: second member
300: first flow path 301: seawater inflow section
310: Seawater suction unit
400: 2nd Euro
410: fresh water supply part 420: fresh water discharge part
500: Porous electrode
600: filter
700: brine supply part

Claims (14)

A main body having a seawater inflow section, a fresh water supply section, a fresh water discharge section, and a seawater sucking section;
A plurality of ion exchange membranes disposed within the body and having a structured surface;
And a porous electrode arranged to produce electricity by a difference in concentration of seawater and fresh water passing through the ion exchange membrane,
A plurality of ion exchange membranes are arranged to form a first flow path through which the seawater flows through the space therebetween and a second flow path through which the fresh water flows,
The ion exchange membrane includes a channel for guiding the fluid flow on the ion exchange membrane, the channel being formed of the same material as the ion exchange membrane, the plurality of first members being spaced apart from each other along the height direction of the channel; A second member formed of a different material from the first member, the second member being connected to two adjacent first members,
The second member may be an acrylic-based, vinyl-based, or epoxy-based silane coupling agent; Catechol compounds comprising polydodamine; A polymer electrolyte which induces an electrostatic attractive force; And an adhesive comprising cyanoacrylate; ≪ RTI ID = 0.0 > 1, < / RTI >
delete The method according to claim 1,
Wherein at least one first member of the channel is adapted to be in contact with the ion exchange membrane.
delete The method according to claim 1,
Wherein at least a part of the first member and the second member is hydrophobic. ◈ Claim 6 is abandoned due to the registration fee. The method according to claim 1,
Wherein the main body further comprises a filter provided to prevent the inflow of suspended matter in seawater into the first flow path. The method according to claim 1,
Wherein the first flow path and the seawater suction unit are fluidly connected to each other and the seawater stored in the first flow path is discharged through the seawater suction unit to the outside of the main body. ◈ Claim 8 is abandoned due to the registration fee. The method according to claim 1,
Wherein the ion exchange membrane is provided with a cation exchange membrane and an anion exchange membrane alternately. ◈ Claim 9 is abandoned upon payment of registration fee. The method according to claim 1,
Wherein the fresh water uses at least one of industrial wastewater discharge water treated secondarily, sewage treatment plant discharge water, and power plant discharge water. The method according to claim 1,
Wherein the porous electrode is a porous accumulator electrode made of carbon. 11. The method of claim 10,
Wherein the electrostatic electrode is made of a porous carbon material selected from the group consisting of carbon felt, carbon cloth, activated carbon, and surface activated carbon. 11. The method of claim 10,
Wherein the electrolyte of the capacitive electrode is an aqueous solution of sodium chloride or sodium chloride (NaCl). The method according to claim 1,
Further comprising a brine supply unit for supplying salt water having a concentration higher than that of seawater to said second flow path so as to generate a reverse potential. ◈ Claim 14 is abandoned due to registration fee. The method according to claim 1,
Wherein the seawater sucked through the seawater suction unit is combined with the desalination process to produce fresh water and highly concentrated brine.

Images