ELECTROCHEMICAL SYSTEM

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2024-0047674, filed on Apr. 8, 2024, and Korean Patent Application No. 10-2024-0073918, filed on Jun. 5, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in their entirety are herein incorporated by reference.

BACKGROUND

1. Field

The disclosure relates to an electrochemical system applicable to an electrochemical device configured to reduce carbon oxides.

2. Description of the Related Art

A reduction product generated on a cathode inside an electrochemical device may cross over an electrolyte membrane and may be contained in an anolyte.

For a high concentration of the reduction product contained in the anolyte inside the electrochemical device, the reduction product may be oxidized on an anode.

When the reduction product is oxidized on the anode inside the electrochemical device, the reduction efficiency of the electrochemical device may be degraded.

SUMMARY

Provided is an electrochemical system configured to circulate an anolyte to the outside of an electrochemical device.

Provided is an electrochemical system configured to separate, in real time, a reduction product contained in an anolyte.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to an aspect of the disclosure, in an electrochemical system including a purification module configured to separate, in real time, a reduction product reduced by an electrochemical device configured to reduce a carbon oxide, the electrochemical device includes an electrolyte membrane including a first surface and a second surface that are opposite to each other, a cathode arranged in parallel with the first surface of the electrolyte membrane and in which the reduction product is generated, an anode arranged in parallel with the second surface of the electrolyte membrane, and an anolyte for exchanging electric charges with the anode and containing at least a part of the reduction product having crossed over the electrolyte membrane, and the purification module includes a first flow path configured to extract the anolyte to the outside of the electrochemical device, a separation unit configured to separate the reduction product from the anolyte extracted to the outside of the electrochemical device, and a second flow path configured to supply, to the electrochemical device, the anolyte from which the reduction product is separated.

The purification module may control anolyte environmental conditions in the electrochemical device to be constant.

The anolyte environmental conditions controlled by the purification module may include at least one of pH conditions, concentration conditions of the reduction product, and an amount of the anolyte.

The purification module may include a pH sensor configured to measure a pH of the anolyte extracted to the outside of the electrochemical device and/or a concentration sensor configured to measure a concentration of the reduction product contained in the anolyte and an anolyte chamber connected to the second flow path and configured to replenish the anolyte, from which the reduction product is separated, to the inside of the electrochemical device.

The purification module may further include a third flow path connected to the first flow path and the second flow path and through which the anolyte extracted to the outside of the electrochemical device to selectively bypass the separation unit.

The separation unit may include a pervaporation unit or a vacuum membrane distillation unit.

The reduction product may include a multicarbon compound including at least one of methanol, ethanol, 1-propanol, 2-propanol, formic acid, acetic acid, acetaldehyde, and ethylene glycol.

The reduction product may include ethanol.

The anolyte may include at least one of KHCO₃, KOH, and H₂SO₄.

The electrochemical device may include a membrane electrode assembly (MEA) or a flow cell.

According to an aspect of the disclosure, a method of controlling anolyte environmental conditions in an electrochemical device configured to reduce a carbon oxide includes: circulating an anolyte to communicate with a purification module arranged outside the electrochemical device, measuring, by the purification module, the anolyte environmental conditions, separating, by a separation unit in the purification module, a reduction product from the anolyte, when the anolyte environmental conditions do not satisfy a predetermined criterion, and supplying the anolyte, from which the reduction product is separated, back to inside of the electrochemical device.

The anolyte environmental conditions may include pH conditions and/or concentration conditions of the reduction product.

The measuring, by the purification module, of the anolyte environmental conditions may include measuring, by a detection sensor disposed on a first flow path arranged in a front end of the separation unit, the anolyte environmental conditions.

The measuring, by the purification module, of the anolyte environmental conditions may include measuring, by a detection sensor disposed on a second flow path arranged in a rear end of the separation unit, the anolyte environmental conditions.

A case where the anolyte environmental conditions do not satisfy the predetermined criterion may include a case where a pH of the anolyte extracted to an outside of the electrochemical device is less than or equal to a first preset value or a case where a concentration of the reduction product is greater than or equal to a second preset value.

The method may further include, after the measuring, by the purification module, of the anolyte environmental conditions, when the pH of the anolyte exceeds the first preset value or the concentration of the reduction product is less than the second preset value, supplying, by the purification module, the anolyte, extracted to the outside of the electrochemical device, back to the electrochemical device without to passing through the separation unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain embodiments will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of an electrochemical system according to an embodiment;

FIG. 2 is an exploded perspective view of an electrochemical device according to an embodiment;

FIG. 3 is a diagram to describe a detection sensor according to an embodiment;

FIG. 4 is a diagram to describe a detection sensor according to an embodiment;

FIG. 5 is diagram to describe an anolyte chamber according to an embodiment;

FIG. 6 is a diagram to describe a third flow path according to an embodiment;

FIG. 7 is a flowchart to describe a method of controlling an anolyte environment condition inside an electrochemical device, according to an embodiment;

FIG. 8 is a flowchart to describe a method of controlling an anolyte environment condition inside an electrochemical device, according to an embodiment;

FIG. 9 is a schematic diagram to describe an electrochemical system including a plurality of electrochemical devices according to an embodiment; and

FIG. 10 is a schematic diagram to describe an electrochemical system including a plurality of electrochemical devices according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

Hereinafter, various embodiments disclosed herein will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals denote like components, and sizes of components in the drawings may be exaggerated for convenience of explanation. Meanwhile, embodiments to be described are merely examples, and various modifications may be made from such embodiments. When an expression “above” or “on” may include not only “directly on/under/at left/right contactually”, but also “on/under/at left/right contactlessly”. Singular forms may include plural forms unless apparently indicated otherwise contextually. When a portion is referred to as “comprises” a component, the portion may not exclude another component but may further include another component unless stated otherwise. The use of the terms of “the above-described” and similar indicative terms may correspond to both the singular forms and the plural forms. When there is an explicit description of the order of operations of the method or there is no description contrary thereto, these operations may be performed in an appropriate order and the order is not necessarily limited to the described order. The term used herein such as “unit” or “module” indicates a unit for processing at least one function or operation, and may be implemented in hardware, software, or in a combination of hardware and software. Connections of lines or connection members between components shown in the drawings are illustrative of functional connections and/or physical or circuit connections, and in practice, may be represented as alternative or additional various functional connections, physical connections, or circuit connections. The use of all examples or exemplary terms is only to describe technical spirit in detail, and the scope is not limited by these examples or terms unless limited by the claims.

It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein. Hereinbelow, an electrochemical system 1 according to an embodiment will be described in more detail.

FIG. 1 is a schematic diagram of the electrochemical system 1 according to an embodiment. FIG. 2 is an exploded perspective view of an electrochemical device 2 according to an embodiment.

Referring to FIGS. 1 and 2, the electrochemical system 1 according to an embodiment may include the electrochemical device 2 configured to reduce carbon oxides. A carbon oxide that may be reduced by the electrochemical device 2 may include, but not limited to, at least one type of a carbon dioxide and a carbon monoxide. The carbon oxide may be reduced to a multicarbon compound by the electrochemical device 2. The electrochemical device 2 may synthesize the multicarbon compound by reducing the carbon oxide. Herein, the multicarbon compound may include methanol, ethanol, 1-propanol, 2-propanol, formic acid, acetic acid, acetaldehyde, ethylene glycol, etc.

The electrochemical device 2 according to an embodiment may reduce the carbon oxide by reducing the carbon oxide supplied from the outside into a multicarbon compound. The electrochemical device 2 may reduce the carbon oxide supplied from the outside to the multicarbon compound, e.g., ethanol, etc. The carbon oxide reduced by the electrochemical device 2 may be referred to as a “reduction product”.

The electrochemical device 2 according to an embodiment may include an electrolyte membrane 20, a cathode 21, and an anode 22. The electrolyte membrane 20 may exchange electric charges with the cathode 21. The electrolyte membrane 20 may exchange electric charges with the anode 22. The electrolyte membrane 20 may be disposed between the cathode 21 and the anode 22 and may electrically connect the cathode 21 to the anode 22. The electrolyte membrane 20 may include, but is not limited to, an anion exchange membrane (“AEM”) or a cation exchange membrane (“CEM”). For example, the electrolyte membrane 20 may include a proton exchange membrane (“PEM”).

The electrochemical device 2 according to an embodiment may include a first housing 25 and a second housing 26. Between the first housing 25 and the second housing 26, the cathode 21, the electrolyte membrane 20, and the anode 22 may be sequentially disposed. The first housing 25 may face the cathode 21. The carbon oxide may be supplied to the inside of the electrochemical device 2 through the first housing 25. The carbon oxide may be supplied to the cathode 21 through the first housing 25.

When the electrochemical device 2 according to an embodiment operates, a reduction reaction may occur on the cathode 21. The carbon oxide may be reduced to a reduction product on the cathode 21 of the electrochemical device 2. The reduction product may be generated on the cathode 21. At least a part of the reduction product may travel to the outside of the electrochemical device 2 through the first housing 25. However, at least a part of the reduction product may cross over the electrolyte membrane 20 in a direction toward the anode 22, as described below in more detail.

The electrolyte membrane 20 according to an embodiment may include a first surface 201 and a second surface 202 that are opposite to each other. The cathode 21 and anode 22 may be formed in a film form to correspond to the first surface 201 and the second surface 202 of the electrolyte membrane 20, respectively. The cathode 21 may be disposed on the first surface 201 of the electrolyte membrane 20. The anode 22 may be disposed on the second surface 202 of the electrolyte membrane 20.

External voltage may be applied to the anode 22 and the cathode 21 such that the electrochemical device 2 according to an embodiment may reduce the carbon oxide. External voltage may be applied between the anode 22 and the cathode 21 such that a current density of 50 microamperes per square centimeters (mA/cm²) or more may be formed between the anode 22 and the cathode 21 of the electrochemical device 2. In another embodiment, external voltage may be applied to the anode 22 and the cathode 21 such that a current density of 100 mA/cm² or more may be formed between the anode 22 and the cathode 21 of the electrochemical device 2.

The cathode 21 according to an embodiment may be disposed to face the first surface 201 of the electrolyte membrane 20. That is, the cathode 21 may be disposed in parallel to the first surface 201 of the electrolyte membrane 20. When the cathode 21 is disposed in parallel to the first surface 201 of the electrolyte membrane 20, an area in which the cathode 21 may exchange electric charges with the electrolyte membrane 20 may be large.

The anode 22 according to an embodiment may be disposed to face the second surface 202 of the electrolyte membrane 20. That is, the anode 22 may be disposed in parallel to the second surface 202 of the electrolyte membrane 20. When the anode 22 is disposed in parallel to the second surface 202 of the electrolyte membrane 20, an area in which the anode 22 may exchange electric charges with the electrolyte membrane 20 may be large.

The cathode 21 according to an embodiment may be pressed onto the first surface 201 of the electrolyte membrane 20. The anode 22 may be pressed onto the second surface 202 of the electrolyte membrane 20. When the cathode 21 and the anode 22 are pressed onto the first surface 201 and the second surface 202 of the electrolyte membrane 20, respectively, an electrical resistance between the cathode 21 and the anode 22 may not be great. For example, the electrochemical device 2 may include a membrane electrode assembly (“MEA”). However, an arrangement relationship among the cathode 21, the anode 22, and the electrolyte membrane 20 is not limited to the foregoing description. For another example, the electrochemical device 2 may include a flow cell in which the cathode 21 and the electrolyte membrane 20 are separated from each other by a predetermined space and a catholyte electrically connects the cathode 21 to the electrolyte membrane 20.

The first surface 201 and the second surface 202 of the electrolyte membrane 20 according to an embodiment may have the same type of electric charges. For example, the first surface 201 and the second surface 202 of the electrolyte membrane 20 may have positive electric charges. For another example, the first surface 201 and the second surface 202 of the electrolyte membrane 20 may have negative electric charges. However, the types of the electric charges of the first surface 201 and the second surface 202 of the electrolyte membrane 20 are not limited to the foregoing description. For still another example, the first surface 201 and the second surface 202 of the electrolyte membrane 20 may have different types of electric charges.

The electrolyte membrane 20 between the cathode 21 and the anode 22 according to an embodiment may include one type of an AEM or a PEM. For example, the cathode 21 and the anode 22 may contact opposite sides of the AEM. For another example, the cathode 21 and the anode 22 may contact opposite sides of the PEM. When the electrolyte membrane 20 between the cathode 21 and the anode 22 includes one type of exchange membranes, a resistance of the MEA may not be great. When the electrolyte membrane 20 between the cathode 21 and the anode 22 includes one type of exchange membranes, stability of the MEA may be high. However, the foregoing description of the type of electrolyte membrane 20 between the cathode 21 and the anode 22 is only an example description and the disclosure is not limited thereto. For another example, the electrolyte membrane 20 may include a bipolar membrane formed by joining an AEM and a PEM.

The electrochemical device 2 according to an embodiment may include an anolyte. The anolyte may exchange electric charges with the anode 22. The anolyte may include, but not limited to, at least one of KHCO₃, KOH, and H₂SO₄. A concentration of the anolyte may be, but not limited to, at least about 0.01 molarity (M) but not more than about 10 M.

The anode 22 according to an embodiment may include a porous material. At least a part of the anolyte may be dipped in the anode 22. The anolyte may electrically connect the electrolyte membrane 20 to the anode 22. However, the foregoing description of the material of the anode 22 and electrical connection between the electrolyte membrane 20 and the anode 22 is only an example, and the disclosure is not limited thereto.

The anolyte according to an embodiment may be circulated in communication with the outside of the electrochemical device 2. More specifically, at least a part of the anolyte may be extracted to the outside of the electrochemical device 2, undergo a predetermined treatment process, and be supplied to the inside of the electrochemical device 2. By circulating the anolyte in communication with the outside of the electrochemical device 2, anolyte environmental conditions in the electrochemical device 2 may be controlled to be constant. More specifically, by circulating the anolyte in communication with the outside of the electrochemical device 2, an oxide oxidized on the anode 22 may be discharged to the outside of the electrochemical device 2. For example, when the anolyte is circulated, hydroxide ions generated on the cathode 21 may be discharged to the outside of the electrochemical device 2. For example, when the anolyte is circulated, oxygen molecules generated on the cathode 21 may be discharged to the outside of the electrochemical device 2.

The second housing 26 according to an embodiment may be disposed to face the anode 22. The second housing 26 may include an anolyte extraction unit 261 and an anolyte supply unit 262. At least a part of the anolyte may be extracted to the outside of the electrochemical device 2 through the anolyte extraction unit 261 of the second housing 26 and may be supplied back to the inside of the electrochemical device 2 through the anolyte supply unit 262 after passing through a predetermined treatment process.

In addition, at least a part of a reduction product generated on the cathode 21 may cross over the electrolyte membrane 20. More specifically, the reduction product generated on the cathode 21 may move through the first surface 201 and the second surface 202 of the electrolyte membrane 20 in a direction toward the anode 22. For example, ethanol generated on the cathode 21 may move through the first surface 201 and the second surface 202 of the electrolyte membrane 20 in a direction toward the anode 22. The anolyte may contain at least a part of the reduction product crossing over the electrolyte membrane 20. The reduction product crossing over the electrolyte membrane 20 may accumulate in the anolyte. In this case, when the concentration of the reduction product contained in the anolyte is excessive, the reduction product may be oxidized on the anode 22. For example, when the ethanol generated on the cathode 21 crosses over the electrolyte membrane 20 and accumulates excessively in the anolyte, the ethanol may be oxidized to acetate on the anode 22. For example, when the ethanol generated on the cathode 21 crosses over the electrolyte membrane 20 and accumulates excessively in the anolyte, the ethanol may be oxidized to acetaldehyde on the anode 22. When the reduction product is oxidized on the anode 22, the pH inside the electrochemical device 2 may decrease. In other words, the pH of the anolyte inside the electrochemical device 2 may decrease. When the pH of the anolyte inside the electrochemical device 2 is excessively low, the reduction efficiency of the electrochemical device 2 may decrease. Herein, the reduction efficiency may include, but not limited to, a Faraday efficiency (“FE”). In this case, by controlling the concentration of the reduction product contained in the anolyte not to increase excessively, the reduction efficiency of the electrochemical device 2 may be prevented from being degraded due to excessive oxidation of the reduction product on the anode 22.

The electrochemical system 1 according to an embodiment may include a purification module 5. The purification module 5 may be configured to separate, in real time, a reduction product reduced by the electrochemical device 2. The separation of the reduction product by the purification module 5 may include separating the reduction product contained in the anolyte from the anolyte. The “real-time separation” may mean, but not limited to, that an operation of the electrochemical device 2 and the separation of the reduction product are performed at the same time.

The purification module 5 according to an embodiment may control the anolyte environmental conditions in the electrochemical device 2 to be constant. The anolyte environmental conditions may include pH conditions. Controlling the anolyte environmental conditions to be constant may include controlling the pH of the anolyte not to fall out of a predetermined range. The anolyte environmental conditions may include concentration conditions of the reduction product. Controlling the anolyte environmental conditions to be constant may include controlling the concentration of the reduction product contained in the anolyte not to fall out of a predetermined range. When the purification module 5 controls the anolyte environmental conditions to be constant, the reduction efficiency of the electrochemical device 2 may be effectively prevented from degrading.

The purification module 5 according to an embodiment may be disposed the outside the electrochemical device 2. The purification module 5 may circulate the anolyte to the outside of the electrochemical device 2. More specifically, the purification module 5 may extract at least a part of the anolyte to the outside of the electrochemical device 2 and supply the anolyte back to the inside of the electrochemical device 2 after a predetermined treatment process. The concentration of the reduction product contained in the anolyte extracted from the inside of the electrochemical device 2 by the purification module 5 may be different from, but not limited to, the concentration of the reduction product contained in the anolyte supplied to the electrochemical device 2 by the purification module 5.

The purification module 5 according to an embodiment may include a first flow path 51, a separation unit 50, and a second flow path 52. The first flow path 51 may be configured to extract at least a part of the anolyte to the outside of the electrochemical device 2. The first flow path 51 may be connected to, for example, but not limited to, the anolyte extraction unit 261 of the second housing 26. The separation unit 50 may be connected to the first flow path 51. At least a part of the anolyte inside the electrochemical device 2 may reach the separation unit 50 via the first flow path 51. The separation unit 50 may separate the reduction product from the anolyte extracted to the outside of the electrochemical device 2. The second flow path 52 may be connected to the separation unit 50. The second flow path 52 may supply the anolyte from which the reduction product is separated, to the electrochemical device 2. The second flow path 52 may be connected to, for example, but not limited to, the anolyte supply unit 262 of the second housing 26. That is, the purification module 5 may circulate the anolyte to the outside of the electrochemical device 2 via the first flow path 51, the separation unit 50, and the second flow path 52.

The separation unit 50 according to an embodiment may reduce the concentration of the reduction product contained in the anolyte circulated in the purification module 5. In other words, the concentration of the reduction product contained in the anolyte may decrease as the anolyte passes through the separation unit 50. The concentration of the reduction product contained in the anolyte moving in the second flow path 52 may be lower than the concentration of the reduction product contained in the anolyte moving in the first flow path 51. The purification module 5 may extract the anolyte including the reduction product of a high concentration in the electrochemical device 2 and separate the reduction product from the anolyte, thereby supplying the anolyte including the reduction product of a low concentration to the electrochemical device 2. The purification module 5 may extract the anolyte in the electrochemical device 2, separate the reduction product contained in the anolyte, and supply the anolyte, from which the reduction product is separated, back to the electrochemical device 2, thereby controlling the concentration of the reduction product contained in the anolyte in the electrochemical device 2 to be maintained below a predetermined value. The purification module 5 may control the concentration of the reduction product contained in the anolyte in the electrochemical device 2 not to be excessively high, thereby effectively preventing the reduction efficiency of the electrochemical device 2 from decreasing.

The separation unit 50 according to an embodiment may provide a separator structure that selectively transmits the reduction product in the anolyte containing the reduction product. When the anolyte containing the reduction product passes through the separation unit 50, the reduction product may be selectively transmitted through the separator structure. However, the selective transmission of the reduction product through the separator structure may not mean that the anolyte may not pass through the separator structure. In other words, the separator structure may provide a structure through which the reduction product more easily passes than the anolyte, such that the reduction product may be separated from the anolyte. The separator structure may include, but not limited to, a zeolite material. To the separation unit 50, various principles for separating the reduction product from the anolyte containing the reduction product as well as the separator structure may be applied.

A principle by which the separation unit 50 according to an embodiment separates the reduction product from the anolyte may include a diffusion principle based on the transmission speed difference between the anolyte and the reduction product, e.g., solution-diffusion and/or adsorption diffusion, etc. For example, the separation unit 50 may include a pervaporation unit. When the separation unit 50 includes the pervaporation unit, the reduction product may be separated from the anolyte in units of molecules. When the separation unit 50 includes the pervaporation unit, process stability may be high. The reduction product separated from the anolyte by the separation unit 50 may have, but not limited to, a liquid phase.

A principle by which the separation unit 50 according to another embodiment separates the reduction product from the anolyte may include using the saturation pressure difference on a saturation curve of each of the anolyte and the reduction product. The separation unit 50 may evaporate at least a part of the reduction product contained in the anolyte by heating the anolyte. In still another embodiment, a principle by which the separation unit 50 separates the reduction product from the anolyte may include using the polarity difference between the anolyte and the reduction product. For example, the separation unit 50 may include a vacuum membrane distillation (“VMD”) unit.

The purification module 5 according to an embodiment may separate the reduction product contained in the anolyte and extract the reduction product of a high concentration. The purification module 5 may separate the reduction product from the anolyte and accumulate the concentrated reduction product. The purification module 5 may include a storage unit 500. The storage unit 500 may be connected to the separation unit 50 to accumulate the concentrated reduction product. The concentration of the reduction product accumulating in the storage unit 500 may be about 0.01 weight percentages (wt %) to about 30 wt %. The concentration of the reduction product accumulating in the storage unit 500 may be about 0.1 wt % to about 20 wt %. However, the foregoing description of the concentration of the reduction product extracted by the purification module 5 is only an example, and the disclosure is not limited thereto.

The electrochemical system 1 according to another embodiment may provide a dual reduction product storage route. More specifically, the electrochemical system 1 may provide a route in which the reduction product of the anolyte crossing over the electrolyte membrane 20 in the cathode 21 is separated by the purification module 5 and stored as well as a route in which the reduction product generated in the cathode 21 of the electrochemical device 2 is stored without crossing over the electrolyte membrane 20. However, the foregoing description of a way for the electrochemical system 1 to store the reduction product is only an example and the disclosure is not limited thereto.

FIG. 3 is a diagram to describe a detection sensor 6 according to an embodiment.

Referring to FIGS. 1 to 3, the purification module 5 according to an embodiment may include the detection sensor 6. The detection sensor 6 may measure the anolyte environmental conditions extracted to the outside of the electrochemical device 2. The detection sensor 6 may determine the anolyte environmental conditions in the electrochemical device 2 by measuring the environmental conditions of the anolyte extracted to the outside of the electrochemical device 2. The detection sensor 6 may be disposed on the first flow path 51. However, the foregoing description of an arrangement of the detection sensor 6 is only an example, and the disclosure is not limited thereto.

The detection sensor 6 according to an embodiment may include a pH sensor. The environmental conditions of the anolyte that may be measured by the detection sensor 6 may include pH conditions. The detection sensor 6 may be configured to measure a pH of the anolyte. The anolyte environmental conditions that may be measured by the detection sensor 6 may include concentration conditions of the reduction product contained in the anolyte. The detection sensor 6 may be configured to measure the concentration of the reduction product contained in the anolyte.

The electrochemical system 1 according to an embodiment may determine whether the reduction efficiency of the electrochemical device 2 is maintained appropriately by measuring the anolyte environmental conditions by the detection sensor 6. For example, the electrochemical system 1 may determine that the reduction efficiency of the electrochemical device 2 degrades when the pH of the anolyte measured by the detection sensor 6 is excessively low. For example, the electrochemical system 1 may determine that the reduction efficiency of the electrochemical device 2 degrades when the concentration of the reduction product contained in the anolyte, measured by the detection sensor 6, is excessively high.

The purification module 5 according to an embodiment may control a circulation flow rate of the anolyte depending on the anolyte environmental conditions measured by the detection sensor 6. More specifically, when the pH of the anolyte is excessively low, the purification module 5 may restore the pH of the anolyte in the electrochemical device 2 to a normal range by increasing the circulation flow rate of the anolyte circulated to the outside of the electrochemical device 2. When the concentration of the reduction product contained in the anolyte is excessively high, the purification module 5 may restore the concentration of the reduction product contained in the anolyte in the electrochemical device 2 to a normal range by increasing the circulation flow rate of the anolyte circulated to the outside of the electrochemical device 2. As the purification module 5 controls the circulation flow rate of the anolyte circulated to the outside of the electrochemical device 2 according to the anolyte environmental conditions, the reduction efficiency of the electrochemical device 2 may be prevented from degrading.

FIG. 4 is a diagram to describe the detection sensor 6 according to an embodiment.

Hereinbelow, a redundant description will be omitted and a description mainly of a difference will be made.

Referring to FIGS. 1, 2, and 4, the detection sensor 6 according to an embodiment may be disposed on the second flow path 52. When the detection sensor 6 is disposed on the second flow path 52, the environmental conditions of the anolyte supplied to the electrochemical device 2 may be measured. When the detection sensor 6 is disposed on the second flow path 52, the detection sensor 6 may measure the concentration of the anolyte from which at least a part of the reduction product is separated. When the detection sensor 6 is disposed on the second flow path 52, the anolyte containing the reduction product of a high concentration may be prevented from being excessively loaded onto the detection sensor 6. When the detection sensor 6 is disposed on the second flow path 52, the durability of the detection sensor 6 may be extended.

However, the foregoing description of an arrangement of the detection sensor 6 is only an example, and the disclosure is not limited thereto. For example, the detection sensor 6 may be arranged on each of the first flow path 51 and the second flow path 52. When the detection sensor 6 is arranged on each of the first flow path 51 and the second flow path 52, the performance of the separation unit 50 to separate the reduction product from the anolyte may be measured.

In addition, at least a part of the anolyte may be separated together with the reduction product through the separation unit 50. The amount of anolyte moving through the second flow path 52 may be less than the amount of anolyte moving through the first flow path 51. The electrochemical system 1 may further supply anolyte from the outside of the electrochemical device 2 to appropriately maintain the amount of anolyte in the electrochemical device 2.

FIG. 5 is diagram to describe an anolyte chamber 54 according to an embodiment.

Referring to FIGS. 1, 2, and 5, the purification module 5 according to an embodiment may include the anolyte chamber 54. The anolyte chamber 54 may control the anolyte environmental conditions of the electrochemical system 1 by accommodating extra anolyte. The anolyte chamber 54 may be connected to the separation unit 50. The anolyte chamber 54 may be connected to the second flow path 52. The anolyte chamber 54 may accommodate the anolyte from which the reduction product is separated by the separation unit 50. The anolyte chamber 54 may be configured to replenish the anolyte to the inside of the electrochemical device 2.

The anolyte chamber 54 according to an embodiment may control the amount of anolyte moving through the first flow path 51 and the second flow path 52 to appropriately maintain the amount of anolyte in the electrochemical device 2. More specifically, the anolyte chamber 54 may replenish the anolyte, separated together with the reduction product by the separation unit 50, to the inside of the electrochemical device 2 through the second flow path 52, thereby controlling the amount of anolyte of the electrochemical device 2 to be maintained appropriately.

The detection sensor 6 according to an embodiment may be disposed on the anolyte chamber 54. When the detection sensor 6 is disposed on the anolyte chamber 54, the environmental conditions of the anolyte supplied to the electrochemical device 2 may be measured. However, the foregoing description of an arrangement of the detection sensor 6 is only an example, and the disclosure is not limited thereto.

FIG. 6 is a diagram to describe a third flow path 53 according to an embodiment.

Referring to FIGS. 1 to 6, the purification module 5 according to an embodiment may include the third flow path 53. The third flow path 53 may be connected to the first flow path 51 and the second flow path 52 and configured to selectively bypass anolyte. The third flow path 53 may provide a bypass route such that anolyte extracted to the outside of the electrochemical device 2 may be supplied back to the electrochemical device 2 without passing through the separation unit 50.

The electrochemical system 1 according to an embodiment may provide a plurality of routes through which the anolyte is circulated to the outside of the electrochemical device 2. More specifically, the electrochemical system 1 may provide a route through which the anolyte extracted to the outside of the electrochemical device 2 is circulated to pass through the separation unit 50 and a route through which the extracted anolyte is provided back to the electrochemical device 2 without passing through the third flow path 53. The electrochemical system 1 may efficiently circulate the anolyte by providing a selective circulation route depending on the anolyte environmental conditions.

Hereinbelow, a method, performed by the electrochemical system 1, of controlling the anolyte environmental conditions in the electrochemical device 2 will be described in more detail. In this case, a redundant description will be omitted and a description mainly of a difference will be made.

FIG. 7 is a flowchart to describe a method of controlling an anolyte environment condition inside an electrochemical device, according to an embodiment. FIG. 8 is a flowchart to describe a method of controlling an anolyte environment condition inside an electrochemical device, according to an embodiment.

Referring to FIGS. 1 to 8, a method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment may include operation S101 of circulating the anolyte to communicate with the purification module 5 disposed outside the electrochemical device 2. Operation S101 of circulating the anolyte to communicate with the purification module 5 disposed outside the electrochemical device 2 may include an operation of extracting, by the first flow path 51, the anolyte to the outside of the electrochemical device 2 and supplying, by the second flow path 52, the anolyte to the electrochemical device 2.

The method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment may include operation S102, performed by the purification module 5, of measuring the anolyte environmental conditions. The anolyte environmental conditions that may be measured by the purification module 5 may include pH conditions of the anolyte and/or the concentration conditions of the reduction product contained in the anolyte. In an embodiment, the operation S102, performed by the purification module 5, of measuring the anolyte environmental conditions may include an operation of measuring the anolyte environmental conditions in the first flow path 51 disposed at a front end of the separation unit 50. In another embodiment, the operation S102, performed by the purification module 5, of measuring the anolyte environmental conditions may include an operation of measuring the anolyte environmental conditions in the second flow path 52 disposed at a rear end of the separation unit 50.

The method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment may include operation S103, performed by the separation unit 50, of separating the reduction product from the anolyte. Operation S103, performed by the separation unit 50, of separating the reduction product from the anolyte may include an operation of separating the reduction product from the anolyte when the anolyte environmental conditions do not satisfy a predetermined criterion (S1021). Herein, a case where the anolyte environmental conditions do not satisfy the predetermined criterion may include a case where the pH of the anolyte is less than a preset value or the concentration of the reduction product contained in the anolyte is greater than or equal to a preset value. A method of controlling the anolyte environmental conditions in the electrochemical device 2 may control the concentration of the reduction product contained in the anolyte not to be excessively high, thereby preventing the reduction efficiency of the electrochemical device 2 from degrading.

The method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment may include operation S104 of supplying the anolyte back to the inside of the electrochemical device 2. Operation S104 of supplying the anolyte back to the inside of the electrochemical device 2 may include an operation of supplying the anolyte from which the reduction product is separated, to the inside of the electrochemical device 2. A method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment may control the amount of anolyte in the electrochemical device 2 to be maintained appropriately, by supplying the anolyte from which the reduction product is separated back to the inside of the electrochemical device 2.

Furthermore, the method of controlling the anolyte environmental conditions in the electrochemical device 2 may include bypassing the anolyte without separating the reduction product therefrom when the anolyte environmental conditions satisfy a predetermined criterion.

The method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment may include operation S1021 of determining whether the anolyte environmental conditions satisfy a reference value. Operation S1021 of determining whether the anolyte environmental conditions satisfy a reference value may include an operation of determining whether the pH of the anolyte exceeds a preset value or the concentration of the reduction product is less than a preset value.

In the method of controlling the anolyte environmental conditions in the electrochemical device 2 according to an embodiment, after operation S102, performed by the purification module 5, of measuring the anolyte environmental conditions, when the pH of the anolyte exceeds the preset value or the concentration of the reduction product is less than the preset value, the purification module 5 may bypass the anolyte such that the anolyte does not pass through the separation unit 50. The method of controlling the anolyte environmental conditions in the electrochemical device 2 may provide a plurality of routes in which the anolyte in the electrochemical device 2 may be circulated to the outside of the electrochemical device 2.

FIG. 9 is a schematic diagram to describe the electrochemical system 1 including a plurality of electrochemical devices 2 according to an embodiment.

Referring to FIGS. 1 to 9, the electrochemical system 1 according to an embodiment may include a plurality of electrochemical devices 2. When the electrochemical system 1 includes the plurality of electrochemical devices 2, a flow rate of a carbon oxide that may be reduced by the electrochemical system 1 may be great.

In the electrochemical system 1 including the plurality of electrochemical devices 2 according to an embodiment, the plurality of electrochemical devices 2 may be arranged in a line. In the electrochemical system 1 including the plurality of electrochemical devices 2, the purification module 5 may include the first flow path 51 configured to extract the anolyte from each of the plurality of electrochemical devices 2. The purification module 5 may include the separation unit 50 that is connected to the first flow path 51 to separate the reduction product contained in the anolyte. The purification module 5 may include the second flow path 52 configured to supply, to each of the plurality of electrochemical devices 2, the anolyte from which the reduction product is separated.

FIG. 10 is a schematic diagram to describe the electrochemical system 1 including the plurality of electrochemical devices 2 according to an embodiment.

Referring to FIGS. 1 to 8 and 10, the electrochemical system 1 including the plurality of electrochemical devices 2 may include a plurality of purification modules 5. The plurality of purification modules 5 may correspond to the plurality of electrochemical devices 2, respectively. More specifically, the plurality of separation units 50 may be disposed on upper sides of the plurality of electrochemical devices 2, respectively, rather than back sides of the anodes 22, and the second flow paths 52 may be located behind the cathodes 21. The plurality of separation units 50 may be provided to separate the reduction product from the anolyte extracted from each of the plurality of electrochemical devices 2.

The electrochemical system 1 according to an embodiment may control the anolyte environmental conditions in each of the plurality of electrochemical devices 2, thereby preventing the reduction efficiency of each of the plurality of electrochemical devices 2 from degrading.

The above embodiments are merely illustrative, and various modifications and equivalent other embodiments may be made therefrom by those skilled in the art. Therefore, the true technical protection range of an embodiment should be defined by the technical spirit set forth in the claims.

The electrochemical system according to an embodiment may control the anolyte environmental conditions inside the electrochemical device to be constant.

The electrochemical system according to an embodiment may separate, in real time, the reduction product from the anolyte containing the reduction product.

Embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.