KR102042683B1 - Carbon dioxide utilization system - Google Patents

Abstract

The present invention relates to a carbon dioxide utilization system which produces electricity, hydrogen and bicarbonate ions by using carbon dioxide through a voluntary electrochemical reaction without external power and can recover metal ions generated therefrom. According to the present invention, by using carbon dioxide through a voluntary electrochemical reaction without external power with various metals, electricity, hydrogen and bicarbonate ions can be produced. In addition, the carbon dioxide utilization system additionally comprises a metal recovery unit, thereby recovering metals with high purity consumed in the carbon dioxide utilization system and left in an ionic form.

Description

CO2 utilization system {CARBON DIOXIDE UTILIZATION SYSTEM}

The present invention relates to a carbon dioxide utilization system that utilizes carbon dioxide through a spontaneous electrochemical reaction without an external power source to produce electricity, hydrogen and bicarbonate ions, and recover metal ions generated therefrom.

With the recent industrialization, greenhouse gas emissions have been continuously increasing, and carbon dioxide accounts for the largest portion of greenhouse gases. Carbon dioxide emissions by industry type are the highest in energy sources such as power plants, and carbon dioxide from cement, steel, and refining industries, including power generation, accounts for half of the world's production. CO2 conversion / utilization can be classified into chemical conversion, biological conversion, and direct utilization, and the technical categories can be categorized into catalyst, electrochemical, bioprocess, light utilization, inorganic (carbonate), and polymer. Since carbon dioxide is produced in various industries and processes, and a single technology cannot achieve carbon dioxide reduction, various approaches for carbon dioxide reduction are required.

Currently, the US Department of Energy Department of Energy (DOE) is focusing on CCUS technology that combines Carbon Capture & Storage (CCS) and Carbon Capture & Utilization (CCU) as a technology to reduce carbon dioxide. CCUS technology is recognized as an effective GHG reduction measure, but faces high investment costs, the possibility of release of harmful trapping agents into the air, and low technology maturity. In addition, from an energy and climate policy perspective, CCUS provides a means to substantially reduce greenhouse gas emissions, but there are many complements to the realization of the technology. Therefore, there is a need for developing a new concept of breakthrough technology that more efficiently captures, stores and utilizes carbon dioxide.

As a prior patent document related to the technical field of the present invention, Japanese Patent Laid-Open No. 10-2015-0091834 discloses a sodium secondary battery for capturing carbon dioxide.

Republic of Korea Patent Publication No. 10-2015-0091834 "Carbon Dioxide Capture Secondary Battery" (2015.08.12.)

It is an object of the present invention to provide a system utilizing carbon dioxide, which is a greenhouse gas, through a spontaneous electrochemical reaction without using a separate power source.

Another object of the present invention is to provide a carbon dioxide utilization system that can produce hydrogen with high purity by using carbon dioxide with high purity.

Still another object of the present invention is to provide a carbon dioxide utilization system capable of capturing carbon dioxide into bicarbonate ions.

Another object of the present invention to provide a carbon dioxide utilization system that can recover the metal used in the anode in the carbon dioxide utilization system.

In order to achieve the above object of the present invention, according to an aspect of the present invention, the cathode including a first receiving space, the first aqueous solution and the cathode at least partially submerged in the first aqueous solution, the second receiving space, basic An anode portion including a second phosphorus aqueous solution and an anode of a metal at least partially submerged in the second aqueous solution, and a connection portion connecting the cathode portion and the anode portion, and collecting carbon dioxide introduced into the first aqueous solution as bicarbonate ions; Provided is a carbon dioxide utilization system that generates hydrogen ions and reacts with the electrons of the hydrogen ions to produce hydrogen.

In order to achieve the above object of the present invention, according to another aspect of the present invention, the reaction space for accommodating an aqueous solution, the cathode at least partially submerged in the aqueous solution in the reaction space and at least a portion of the aqueous solution in the reaction space Including a metal anode, the carbon dioxide introduced into the aqueous solution is collected by bicarbonate ions to produce hydrogen ions, and the hydrogen ions and the electrons of the cathode is provided with a carbon dioxide utilization system for producing hydrogen.

In order to achieve the above object of the present invention, according to another aspect of the present invention, the metal recovery unit further comprising a supply unit for receiving a second aqueous solution in which the metal ions oxidized in the anode is dissolved, the supply A recovery space accommodating the second aqueous solution received, a second cathode having the same material as the anode at least partially submerged in the second aqueous solution accommodated in the recovery space, a second anode submerged at least partially in the second aqueous solution accommodated in the recovery space; Provided is a carbon dioxide utilization system comprising a power supply for supplying power to the second cathode and the second anode, recovering the oxidized metal ions from the supplied second aqueous solution.

In order to achieve the above object of the present invention, in accordance with another aspect of the present invention, the metal recovery unit further comprises a metal supply unit for supplying an aqueous solution in which the oxidized metal ions are dissolved in the anode, the supplied aqueous solution A second cathode of the same material as the anode at least partially submerged in the aqueous solution contained in the recovery space, a second anode and at least a portion of the second anode and the second cathode submerged in the aqueous solution contained in the recovery space; Provided with a power supply for supplying power to the anode, there is provided a carbon dioxide utilization system for recovering the oxidized metal ions from the supplied aqueous solution.

According to the present invention, all the objects of the present invention described above can be achieved. Specifically, the use of various metals to generate electricity, hydrogen and bicarbonate ions by utilizing carbon dioxide through a spontaneous electrochemical reaction without a separate external power source.

In addition, the carbon dioxide utilization system further includes a metal recovery unit, so that the metal consumed in the carbon dioxide utilization system and left in the form of ions can be recovered with high purity.

1 is a schematic diagram showing the operation of the carbon dioxide utilization system according to an embodiment of the present invention.
Figure 2 is a schematic diagram showing the operation of the carbon dioxide utilization system according to another embodiment of the present invention.
Figure 3 is a schematic diagram showing the operation of the carbon dioxide utilization system according to another embodiment of the present invention.
Figure 4 is a schematic diagram showing the operation of the carbon dioxide utilization system including a carbon dioxide treatment unit according to an embodiment of the present invention.
5 is a schematic diagram showing an operation process of the carbon dioxide utilization system including a metal recovery unit according to an embodiment of the present invention.

Hereinafter, with reference to the drawings will be described in detail the configuration and operation of the embodiment of the present invention.

1 shows a configuration of a carbon dioxide utilization system according to an embodiment of the present invention. Referring to FIG. 1, a carbon dioxide utilization system 100a according to an embodiment of the present invention includes a cathode unit 110, an anode unit 150, and a connection unit 190 connecting the cathode unit 110 and the anode unit 150. ). The connection unit 190 may be a salt bridge. The carbon dioxide utilization system 100a uses carbon dioxide gas (CO ₂ ), which is a greenhouse gas, as a raw material in a voluntary redox reaction, and produces hydrogen (H ₂ ), which is an environmentally friendly fuel.

The cathode unit 110 includes a first aqueous solution 115 contained in the first accommodating space 111, and a cathode 118 at least partially submerged in the first aqueous solution 115. The first aqueous solution 115 may be an alkaline aqueous solution (in this embodiment, eluted with CO ₂ in a strong basic solution of 1M KOH), seawater, tap water, and distilled water. The cathode 118 is an electrode for forming an electric circuit, and may be carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, metal thin film, or a combination thereof, and a platinum catalyst may also be used. In the case of a catalyst, in addition to the platinum catalyst, all other catalysts that can be generally used as an oxygen generation reaction (HER) catalyst, such as a carbon-based catalyst, a carbon-metal based composite catalyst, and a perovskite oxide catalyst, are also included. The cathode part 110 is provided with a first inlet 112 and a first outlet 113 communicating with the first accommodating space 111. The first inlet 112 is positioned below the first accommodating space 111 to be positioned below the surface of the first aqueous solution 115. The first outlet 113 is positioned above the first accommodating space 111 to be located above the water surface of the first aqueous solution 115. Carbon dioxide used as fuel in the reaction process is introduced into the first accommodating space 111 through the first inlet 112, and if necessary, the first aqueous solution 115 may also be introduced. The gas generated in the reaction process is discharged to the outside through the first outlet 113. Although not shown, the inlet 112 and the outlet 113 may be selectively opened and closed in a timely manner by a valve or the like during the reaction. In the cathode unit 110, a carbon dioxide eluting reaction occurs in the reaction process.

The anode unit 150 includes a second aqueous solution 155 contained in the second accommodating space 151, and an anode 158 at least partially submerged in the second aqueous solution 155. As the second aqueous solution 155, a high concentration of an alkaline solution is used. For example, 1M KOH or 6M KOH may be used. The anode 158 is a metal electrode constituting an electric circuit. In this embodiment, zinc (Zn) or aluminum (Al) is used as the anode 158. In addition, an alloy including zinc or aluminum may be used as the anode 158.

Both ends of the salt bridge (connector 190) are immersed in the first aqueous solution 115 and the second aqueous solution 155, respectively. As the internal solution of the salt bridge, a commonly used salt solution of the salt bridge, such as potassium chloride (KCl), sodium chloride (NaCl), and the like may be used.

Now, the reaction process of the carbon dioxide utilization system 100a described above as the configuration center is described in detail. 1 illustrates a reaction process of the carbon dioxide utilization system 100a. Referring to FIG. 1, carbon dioxide is injected into the first aqueous solution 115 through the inlet 112, and the cathode 110 performs a chemical elution reaction of carbon dioxide as shown in the following [Scheme 1].

Scheme 1

_{H 2 O (l) + CO} 2 (g) → H + (aq) + HCO 3 - (aq)

That is, in the cathode unit 110, carbon dioxide (CO ₂ ) supplied to the cathode unit 110 spontaneously reacts with water (H ₂ O) of the first aqueous solution 115 to form a hydrogen cation (H ⁺ ) and a bicarbonate (HCO). ^₃ generates).

In addition, the cathode 110, the electrical reaction is made as shown in the following [Scheme 2].

Scheme 2

^{2H + (aq) + 2e -} → H 2 (g)

That is, the hydrogen cation (H ⁺ ) in the cathode unit 110 receives electrons (e ⁻ ) to generate hydrogen (H ₂ ) gas. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 113.

In addition, the cathode 110 is a complex hydrogen generation reaction as shown in the following [Reaction Scheme 3].

Scheme 3

_{2H 2 O (l) + 2CO} 2 (g) + 2e - → H 2 (g) + 2HCO 3 - (aq)

In addition, in the anode unit 150, when the anode 158 is zinc (Zn), an oxidation reaction is performed as shown in [Scheme 4].

Scheme 4

^{Zn + 4OH - → Zn (OH} ) 4 2- + 2e - (E0 = -1.25V)

^{_{Zn (OH) 4 2- → ZnO}} + H2O + 2OH -

As a result, when the anode 158 is zinc (Zn), the entire reaction formula formed in the reaction process is as follows.

Scheme 5

_{Zn + 2CO 2 + 2H 2 O} + 2OH - → ZnO + 2HCO 3 - (aq) + H 2 (g) (E0 = 1.25V)

If the anode 158 is aluminum (Al) in the anode unit 150, an oxidation reaction is performed as shown in [Scheme 6].

Scheme 6

^{Al + 3OH - → Al (OH} ) 3 + 3e - (E0 = -2.31V)

As a result, in the case where the anode 158 is aluminum (Al), the entire reaction formula formed in the reaction process is as shown in [Scheme 7].

Scheme 7

_{2Al + 6CO 2 + 6H 2 O} + 6OH - → 2Al (OH) 3 + 6HCO 3 - (aq) + 3H 2 (g) (E0 = 2.31V)

As a result, as can be seen from [Scheme 5] and [Scheme 7], the hydrogen ions generated by the carbon dioxide eluted in the first aqueous solution 115 during the reaction receives electrons from the cathode 118 to the hydrogen gas Reduced, it is discharged through the first outlet 113, the metal anode 158 is changed into the form of oxide. As the reaction proceeds, HCO ₃ ⁻ (bicarbonate ion) is produced in the first aqueous solution 115. When the inner solution of the salt bridge contains sodium ions (Na ⁺ ) such as sodium chloride (NaCl), the salt bridge is used to balance the ions. Sodium ions diffuse from them to exist as ions in the form of aqueous sodium hydrogen carbonate (NaHCO ₃ ) solution. Drying this solution additionally gives a sodium carbonate solid product in the form of baking soda.

2 shows a configuration of a carbon dioxide utilization system 100b according to another embodiment of the present invention. Referring to FIG. 2, the connection part 190 connecting the cathode part 110 and the anode part 150 of the carbon dioxide utilization system 100b according to an embodiment of the present invention has a first accommodation space and the second accommodation space. It is installed between, the ion transport member of the porous structure to block the movement of the first aqueous solution and the second aqueous solution and to pass through the ionic material dissolved in the aqueous solution.

The carbon dioxide utilization system 100b according to the embodiment shown in FIG. 2 has the same configuration as described in detail with reference to FIG. 1 except for the difference in the connection unit 190 described below, and the reaction process as well. Uses carbon dioxide gas as fuel and generates hydrogen gas.

The cathode part 110 is provided with a first inlet 112, a first outlet 113, and a first connector 114 communicating with the first accommodating space 111. The first connector 114 is located below the water surface of the first aqueous solution 115, and the connector 190 is connected to the first connector 114. In the cathode unit 110, a carbon dioxide eluting reaction occurs in the reaction process.

The anode part 150 is provided with a second connector 154 in communication with the second receiving space 151. The second connector 154 is located below the water surface of the second aqueous solution 155, and the connector 190 is connected to the second connector 154.

The connection part 190 according to the present exemplary embodiment includes a connection passage 191 connecting the cathode 110 and the anode part 150 to the porous ion transfer member, and an ion transfer member installed inside the connection passage 191. 192.

The connection passage 191 extends between the first connector 114 formed in the cathode part 110 and the second connector 154 formed in the anode part 150 to form the first accommodation space 111 of the cathode part 110. ) And the second accommodating space 151 of the anode unit 150 communicate with each other. An ion transfer member 192 is installed in the connection passage 191.

The ion transfer member 192 has a disk shape and is installed to block the inside of the connection passage 191. The ion transfer member 192 is made of a porous structure to allow movement of ions between the cathode portion 110 and the anode portion 150, while blocking the movement of the aqueous solutions 115 and 155. In this embodiment, the material of the ion transfer member is described as glass, but the present invention is not limited thereto, and other materials having a porous structure may also be used, which is also within the scope of the present invention. In this embodiment, the ion transfer member 192 has a pore size of 40 to 90 microns corresponding to G2 grade, 15 to 40 microns corresponding to G3 grade, 5 to 15 microns corresponding to G4 grade, Porous glass of 1 to 2 microns corresponding to G5 can be used. The ion transfer member 192 transfers only ions to solve the ion imbalance generated in the reaction process.

3 shows a configuration of a carbon dioxide utilization system 100c according to another embodiment of the present invention. 3, the carbon dioxide utilization system 100c according to an embodiment of the present invention is a reaction space 161 for receiving an aqueous solution 161, at least a portion of the aqueous solution 161 in the reaction space 161 A submerged cathode 118 and a metal anode 158 that is at least partially submerged in the aqueous solution 161 in the reaction space 161.

The reaction vessel 160 provides a reaction space 161 in which an aqueous solution 162 is contained and in which a cathode 118 and an anode 158 are accommodated. The reaction vessel 160 is provided with a first inlet 112 and a first outlet 113 communicating with the reaction space 161. The first inlet 112 is positioned below the reaction space 161 to be below the water surface of the aqueous solution 162. The first outlet 113 is positioned above the reaction space 161 to be located above the water surface of the aqueous solution 162. Carbon dioxide gas, which is used as fuel in the reaction process, is introduced into the reaction space 161 through the first inlet 112, and an aqueous solution 162 may also be introduced if necessary. The gas generated in the reaction process is discharged to the outside through the first outlet 113. Although not shown, the first inlet 112 and the first outlet 113 may be selectively opened and closed at a suitable time by a valve or the like during filling and reaction. The first connector 114 is located below the water surface of the first aqueous solution 115, and the connector 190 is connected to the first connector 114. In the reaction space 161, a carbon dioxide eluting reaction occurs during the reaction.

The reaction vessel 160 provides a reaction space 161 in which an aqueous solution 162 is contained and in which a cathode 118 and an anode 158 are accommodated. The reaction vessel 160 is provided with a first inlet 112 and a first outlet 113 communicating with the reaction space 161. The first inlet 112 is positioned below the reaction space 161 to be below the water surface of the aqueous solution 162. The first outlet 113 is positioned above the reaction space 161 to be located above the water surface of the aqueous solution 162. Carbon dioxide gas, which is used as fuel in the reaction process, is introduced into the reaction space 161 through the first inlet 112, and an aqueous solution 162 may also be introduced if necessary. The gas generated in the reaction process is discharged to the outside through the first outlet 113. Although not shown, the first inlet 112 and the first outlet 113 may be selectively opened and closed at a suitable time by a valve or the like during the reaction. The first connector 114 is located below the water surface of the first aqueous solution 115, and the connector 190 is connected to the first connector 114. In the reaction space 161, a carbon dioxide eluting reaction occurs during the reaction.

The aqueous solution 162 is contained in the reaction space 161, and at least a portion of the cathode 118 and at least a portion of the anode 158 are immersed in the aqueous solution 162. It will be described that a basic solution or seawater is used as the aqueous solution 162 in this embodiment. The aqueous solution 162 becomes weakly acidic by the carbon dioxide gas introduced through the first inlet 112 during the reaction.

The cathode 118 is at least partially submerged in the aqueous solution 162 in the reaction space 161. The cathode 118 is located in the reaction space 161 relatively closer to the first inlet 112 than to the anode 158. The cathode 118 is an electrode for forming an electric circuit, and may be carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, metal thin film, or a combination thereof, and a platinum catalyst may also be used. In the case of the catalyst, in addition to the platinum catalyst, carbon-based catalysts, carbon-metal-based composite catalysts, perovskite oxide catalysts, and all other catalysts that can generally be used as an oxygen evolution reaction (HER) catalyst. During the reaction, a reduction reaction occurs in the cathode 118, and accordingly hydrogen is generated.

The anode 158 is at least partially submerged in the aqueous solution 162 in the reaction space 161. The anode 158 is located relatively far from the first inlet 112 than the cathode 118 in the reaction space 161. The anode 158 is a metal electrode constituting an electric circuit. In this embodiment, the anode 158 is vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), or nickel. It is explained that (Ni), copper (Cu), aluminum (Al) or zinc (Zn) are used. Further, at least one of vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), aluminum (Al), and zinc (Zn) Alloys may also be included. In the reaction, the anode 158 generates an oxidation reaction according to a weakly acidic environment.

Now, the reaction process of the carbon dioxide utilization system 100c described above as the configuration center is described in detail. 3 illustrates a reaction process of the carbon dioxide utilization system 100c. Referring to FIG. 3, carbon dioxide gas is injected into the aqueous solution 162 through the first inlet 112, and a chemical elution reaction of carbon dioxide is performed in the reaction space 161 as shown in the following [Scheme 1].

Scheme 1

_{H 2 O (l) + CO} 2 (g) → H + (aq) + HCO 3 - (aq)

That is, carbon dioxide (CO ₂ ) supplied to the reaction space 161 spontaneously reacts with water (H ₂ O) in the aqueous solution 162 to generate hydrogen cations (H ⁺ ) and bicarbonate (HCO ₃ ⁻ ).

In addition, the cathode 118 is an electrical reaction as shown in the following [Scheme 2].

Scheme 2

^{2H + (aq) + 2e -} → H 2 (g)

That is, the hydrogen cation (H ⁺ ) around the cathode 118 receives the electron (e ⁻ ) to generate a hydrogen (H ₂ ) gas. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 113.

In addition, a complex hydrogen generation reaction is performed around the cathode 118 as shown in the following [Scheme 3].

Scheme 3

_{2H 2 O (l) + 2CO} 2 (g) + 2e - → H 2 (g) + 2HCO 3 - (aq)

In addition, in the anode unit 150, when the anode 158 is zinc (Zn), an oxidation reaction is performed as shown in [Scheme 4].

Scheme 4

^{Zn + 4OH - → Zn (OH} ) 4 2- + 2e - (E0 = -1.25V)

^{_{Zn (OH) 4 2- → ZnO}} + H2O + 2OH -

As a result, when the anode 158 is zinc (Zn), the entire reaction formula formed in the reaction process is as follows.

Scheme 5

_{Zn + 2CO 2 + 2H 2 O} + 2OH - → ZnO + 2HCO 3 - (aq) + H 2 (g) (E0 = 1.25V)

If the anode 158 is aluminum (Al) in the anode 150, an oxidation reaction is performed as shown in [Scheme 6].

Scheme 6

^{Al + 3OH - → Al (OH} ) 3 + 3e - (E0 = -2.31V)

As a result, in the case where the anode 158 is aluminum (Al), the entire reaction formula formed in the reaction process is as shown in [Scheme 7].

Scheme 7

_{2Al + 6CO 2 + 6H 2 O} + 6OH - → 2Al (OH) 3 + 6HCO 3 - (aq) + 3H 2 (g) (E0 = 2.31V)

As a result, as can be seen from [Scheme 5] and [Scheme 7], the hydrogen ions produced by the carbon dioxide eluted in the aqueous solution 162 during the reaction receives electrons from the cathode 118 is reduced to hydrogen gas And is discharged through the first outlet 113, and the metal anode 158 is changed into an oxide. As the reaction proceeds, HCO ₃ ⁻ (bicarbonate ion) is produced in the aqueous solution 162.

4 is a schematic diagram illustrating a reaction process of a carbon dioxide utilization system including a carbon dioxide processing unit 200 according to an embodiment of the present invention. Referring to FIG. 4, the carbon dioxide utilization system 100a, 100b, 100c may further include a carbon dioxide processor 200. The carbon dioxide processing unit 200 includes an aqueous solution that is the same as the first aqueous solution 115 of the cathode unit 110 or the aqueous solution 162 of the reaction space 161. The carbon dioxide processing unit 200 is a cathode 110 or the reaction space 161 and the connection pipe 210 for communicating the carbon dioxide processing unit 200, the second inlet port 220 in which carbon dioxide is introduced, the second located above It may include an outlet 230 and the carbon dioxide circulation supply unit 240. Carbon dioxide utilization system (100a, 100b, 100c) is the same as described in the embodiment shown in Figures 1 to 3, detailed description thereof will be omitted.

The second inlet 220 is located above the connection pipe 210 in the carbon dioxide treatment unit 200, and is located below the water surface of the second outlet 230 and the first aqueous solution 115 or the aqueous solution 162. Carbon dioxide gas used as fuel in the reaction process is introduced into the carbon dioxide processing unit 200 through the second inlet 220. The first aqueous solution 115 or the aqueous solution 162 may also be supplied through the second inlet 220 as necessary. The second inlet 220 and the first outlet 113 may be opened and closed at a suitable time selectively by a valve or the like during the reaction.

The connection pipe 210 is positioned below the second inlet 220 in the carbon dioxide processing unit 200, and the carbon dioxide processing unit 200 is connected to the first accommodation space 111 or the reaction space 161 through the connection pipe 210. Communicating with

The second outlet 230 is positioned above the water surface of the second inlet 220 and the first aqueous solution 115 or the aqueous solution 162 in the carbon dioxide treatment unit 200. Carbon dioxide gas that has not been ionized because it is not dissolved in the first aqueous solution 115 or the aqueous solution 162 in the carbon dioxide treatment unit 200 through the second outlet 230 is discharged to the outside. The carbon dioxide discharged through the second outlet 230 is supplied to the second inlet 220 through the carbon dioxide circulation supply unit 240.

The carbon dioxide circulation supply unit 240 circulates the carbon dioxide discharged through the second outlet 230 to the second inlet 220 and supplies it again.

The connecting pipe 210 is connected to the first inlet 112 of the first receiving space 111 or the reaction space 161. The first accommodating space 111 or the reaction space 161 and the carbon dioxide processor 200 communicate with each other through the connection pipe 210.

Carbon dioxide gas that is not ionized because it is not dissolved in the first aqueous solution 115 or the aqueous solution 162 of the carbon dioxide introduced into the carbon dioxide treatment unit 200 through the second inlet 220 may be the first accommodation space 111 or the reaction space ( 161 does not move to the rising and gathers in the space above the water surface of the first aqueous solution 115 or the aqueous solution 162 in the carbon dioxide treatment unit 200 and is discharged through the second outlet 230, the second outlet 230 The carbon dioxide gas discharged through is supplied to the carbon dioxide processing unit 200 through the second inlet 220 by the carbon dioxide circulation supply unit 240 and recycled. In addition, carbon dioxide gas which is not ionized because it is not dissolved in the first aqueous solution 115 or the aqueous solution 162 of the carbon dioxide introduced into the carbon dioxide treatment unit 200 may not move to the first accommodation space 111 or the reaction space 161. Therefore, high purity hydrogen in which carbon dioxide is not mixed may be discharged through the first outlet 113.

5 is a schematic diagram showing a reaction process of a carbon dioxide utilization system including a metal recovery unit 300 according to an embodiment of the present invention. Referring to FIG. 5, the carbon dioxide utilization system 100a, 100b, 100c may further include a metal recovery unit 300. The metal recovery part 200 includes the same aqueous solution as the second aqueous solution 155 of the anode part 150 or the aqueous solution 162 of the reaction space 161. The metal recovery part 300 may include a supply part 320 that receives the second aqueous solution 155 used in the anode part 150 or the aqueous solution 162 used in the reaction space 161, and the received wastewater solution 155 or 162. A second cathode 330 for recovering metal from the metal, a second anode 340 for forming an electric circuit, and a power supply 350 for supplying power to the second cathode 330 and the second anode 340. It may include. Carbon dioxide utilization system (100a, 100b, 100c) is the same as described in the embodiment shown in Figures 1 to 3, detailed description thereof will be omitted.

The supply unit 320 supplies an aqueous solution 155 or 162 in which metal ions are dissolved from the carbon dioxide utilization systems 100a, 100b, and 100c to the metal recovery unit 300. The supply unit 320 may be opened and closed at a suitable time selectively by a valve or the like as necessary.

At least a part of the second cathode 330 is immersed in the aqueous solution 155 or 162 accommodated in the recovery space 310, and is made of the same material as the anode 158. When the anode 158 of the carbon dioxide utilization systems 100a, 100b, and 100c is zinc (Zn), Zn (OH) ₄ ²⁻ may exist in the supplied aqueous solution 155 or 162. In addition, in the second cathode 330 of the recovery space 310, a reduction reaction may be performed as shown in Scheme 8 below.

Scheme 8

^{_{Zn (OH) 4 2- + 2e}} - → Zn + 4OH -

If the anode 158 is aluminum (Al), Al (OH) ₄ ^2- is present in the supplied aqueous solution 155 or 162. In the second cathode 330 of the recovery space 310, a metal recovery reaction may be performed as shown in Scheme 8 below. A reduction reaction may be performed as shown in Scheme 9 below.

Scheme 9

^{_{Al (OH) 3 + 3e -}} → Al + 3OH -

As can be seen from [Scheme 8] and [Scheme 9], the metal ions dissolved in the aqueous solution (155 or 162) supplied from the utilization system (100a, 100b, 100c) is electrons from the second cathode (330) Can be reduced to metal.

The second anode 340 is at least partially submerged in the aqueous solution accommodated in the recovery space 310, and is an electrode for forming an electrical circuit. The material of the second anode may be carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, metal thin film, or a combination thereof, and a platinum catalyst may also be used. In the case of the catalyst, in addition to the platinum catalyst, carbon-based catalysts, carbon-metal-based composite catalysts, perovskite oxide catalysts, and all other catalysts that can generally be used as an oxygen evolution reaction (HER) catalyst.

In the second anode 310 of the recovery space 310, a metal recovery reaction is performed as shown in [Scheme 10]. An oxidation reaction as shown in [Scheme 10] can be performed.

Scheme 10

_{^{4OH - → 2H 2 O + O}} 2 + 4e -

The power supply 350 is electrically connected to the second cathode 330 and the second anode 340 to provide electricity. The cathode of the power supply unit 350 is electrically connected to the second cathode 330 of the metal recovery unit 300, and the anode of the power supply unit 350 is electrically connected to the second anode 340 of the metal recovery unit 300. Connected. The power supply unit 300 is not limited thereto, but renewable energy such as solar cells and wind power generation may be used as well as general batteries or generators.

Although the present invention has been described through the above embodiments, the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will recognize that such modifications and changes also belong to the present invention.

100a, 100b, 100c: carbon dioxide utilization system
110: cathode 111: first accommodation space
112: first inlet 113: first outlet
114: first connector 115: first aqueous solution
118: cathode 150: anode
151: second accommodation space 154: second connector
155: second aqueous solution 158: anode
160: reaction vessel 161: reaction space
162: aqueous solution 190: connection part
191: connecting passage 192: ion transport member
200: carbon dioxide treatment unit 210: connector
220: second inlet 230: second outlet
240: carbon dioxide circulation supply unit 300: metal recovery unit
310: recovery space 320: supply unit
330: second cathode 340: second anode
350: power supply

Claims (25)

A cathode part comprising a first accommodating space, a first aqueous solution, and a cathode at least partially submerged in the first aqueous solution;
An anode portion comprising a second accommodation space, a basic second aqueous solution and an anode of a metal at least partially submerged in the second aqueous solution;
A connection part connecting the cathode part and the anode part; And
It includes; metal recovery unit,
The carbon dioxide introduced into the first aqueous solution is trapped by bicarbonate ions to generate hydrogen ions, and the anode supplies electrons to the cathode through spontaneous oxidation, and the hydrogen ions react with electrons of the cathode to produce hydrogen. and,
The metal recovering unit may include a supply unit receiving a second aqueous solution in which metal ions oxidized in the anode are dissolved;
A recovery space accommodating the supplied second aqueous solution;
A second cathode of the same material as the anode at least partially submerged in the second aqueous solution contained in the recovery space;
A second anode at least partially submerged in a second aqueous solution accommodated in the recovery space; And
And a power supply unit supplying power to the second cathode and the second anode.
A carbon dioxide utilization system for recovering the oxidized metal ions from the supplied second aqueous solution. The method of claim 1,
The anode material is carbon dioxide utilization system comprising aluminum (Al), zinc (Zn) or their alloys. The method of claim 1,
The connection portion is a carbon dioxide utilization system salt bridge. The method of claim 3, wherein
The internal solution of the salt bridge is carbon dioxide utilization system containing sodium ions. The method of claim 1,
The connecting portion is installed between the first receiving space and the second receiving space, the carbon dioxide utilization system is a porous structure ion transfer member that blocks the movement of the first aqueous solution and the second aqueous solution and allows the movement of ions. The method of claim 5,
And a material of the ion transport member is glass. The method of claim 5,
The pores formed in the ion transfer member is 40 to 90 microns, 15 to 40 microns, 5 to 15 microns or 1 to 2 microns carbon dioxide utilization system. The method of claim 1,
The cathode unit has a first outlet for discharging the generated hydrogen, the first outlet is located carbon dioxide above the water surface of the first aqueous solution. The method of claim 1,
It further comprises a carbon dioxide treatment unit having a first connecting tube in communication with the first receiving space and the first aqueous solution,
The carbon dioxide processing unit is a carbon dioxide utilization system to prevent the non-ionized carbon dioxide is not supplied to the cathode portion of the introduced carbon dioxide. The method of claim 9,
The carbon dioxide processing unit,
The carbon dioxide utilization system for separating the non-ionized carbon dioxide by using the difference in specific gravity with the first aqueous solution in the carbon dioxide treatment unit. The method of claim 9,
The carbon dioxide processing unit,
The carbon dioxide utilization system for collecting the non-ionized carbon dioxide on the water surface of the first aqueous solution in the carbon dioxide treatment unit. The method of claim 9,
The carbon dioxide processing unit,
And an inlet through which carbon dioxide flows in a position lower than the surface of the first aqueous solution in the carbon dioxide treatment unit.
The first connecting pipe is provided with a carbon dioxide utilization system lower than the inlet. The method of claim 9,
The carbon dioxide treatment unit has a carbon dioxide utilization system having a second outlet for discharging carbon dioxide that is not ionized on the water surface of the first aqueous solution in the carbon dioxide treatment unit. The method of claim 9,
The carbon dioxide processing unit further includes a carbon dioxide circulation supply unit supplying unionized carbon dioxide separated from the first aqueous solution in the first accommodation space to the first aqueous solution in the carbon dioxide processing unit. delete delete delete delete delete delete delete delete delete delete delete

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