WO2023195712A1

WO2023195712A1 - Carbon dioxide utilization system

Info

Publication number: WO2023195712A1
Application number: PCT/KR2023/004451
Authority: WO
Inventors: 김건태; 김정원; 표세원; 양예진
Original assignee: 주식회사 디알엠카탈리스트
Priority date: 2022-04-04
Filing date: 2023-04-03
Publication date: 2023-10-12

Abstract

The present invention relates to a secondary battery for producing hydrogen from a neutral aqueous solution containing chlorine ions (Cl-), and a combined power generation system comprising same. The present invention has the advantage of producing various carbonates and hydrogen, an eco-friendly fuel, with high purity by using seawater, a sustainable raw material, and carbon dioxide, a greenhouse gas, as raw materials.

Description

Carbon dioxide utilization system

This application relates to a system for producing hydrogen using carbon dioxide.

Recently, with industrialization, greenhouse gas emissions are continuously increasing, and carbon dioxide accounts for the largest proportion of greenhouse gases. Carbon dioxide emissions by industry type are highest from energy sources such as power plants, and carbon dioxide generated from cement/steel/refining industries, including power generation, accounts for half of global emissions. The field of carbon dioxide conversion/utilization can be broadly divided into chemical conversion, biological conversion, and direct utilization, and technical categories include catalyst, electrochemistry, bioprocess, light utilization, inorganic (carbonation), and polymer. Carbon dioxide is generated from various industries and processes, and since carbon dioxide reduction cannot be achieved with one technology, various approaches are needed to reduce carbon dioxide.

Currently, the U.S. Department of Energy (DOE) is interested in CCUS technology, which is a combination of CCS (Carbon Capture Storage) and CCU (CC & Utilization), as a technology to reduce carbon dioxide and is pursuing multifaceted technology development. CCUS technology is recognized as an effective greenhouse gas reduction method, but it faces the problems of high investment costs, the possibility of releasing harmful collectors into the air, and low technology maturity. Additionally, 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 to develop a new sustainable breakthrough technology that captures, stores, and utilizes carbon dioxide more efficiently.

Meanwhile, the method of producing precipitated calcium carbonate (PCC) is largely produced by injecting carbon dioxide gas into a solution containing dissolved calcium and mixing a soluble carbonate solution with a dissolved calcium salt solution. There are ways to do it, etc.

However, when injecting carbon dioxide in gaseous form, carbon dioxide must be secured separately, and quality control is not easy. Additionally, some of the carbon dioxide that fails to react is released into the atmosphere during the reaction, and carbon dioxide is generated during the firing process, causing environmental pollution. Moreover, the manufacturing process is complicated, and the manufacturing cost increases by calcining limestone at a high temperature of 1000°C or higher to produce quicklime, an intermediate material.

Therefore, in order to reduce the amount of carbon dioxide generated and lower the cost of producing calcium carbonate, there is a problem that calcium components should not be supplied to limestone and a calcium source that does not bind to carbon dioxide should be used.

On the other hand, when liquid calcium carbonate is produced by mixing a dissolved calcium salt solution with a soluble carbonate solution, there is a problem of increased cost because additional carbonate, etc. must be secured.

The first purpose of solving the above problem is as follows.

A cathode portion including a first aqueous solution containing potassium hydroxide accommodated in a first accommodating space, and a cathode at least partially submerged in the first aqueous solution; an anode portion including a second aqueous solution containing chlorine ions (Cl ^- ) accommodated in the second accommodating space, and a metal anode at least partially immersed in the second aqueous solution; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; and a carbon dioxide treatment unit communicating with the first accommodating space and having a first aqueous solution accommodated in the third accommodating space.

The second purpose of solving the above problem is as follows.

a cathode portion including a first aqueous solution contained in a first accommodating space, and a cathode at least partially submerged in the first aqueous solution; An anode comprising a second aqueous solution accommodated in a second accommodating space and containing a calcium salt containing calcium ions (Ca ²⁺ ) and chlorine ions (Cl ^- ), and a metal anode at least partially immersed in the second aqueous solution. wealth; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; and a carbon dioxide treatment unit provided with a first aqueous solution accommodated in a third accommodating space in communication with the first accommodating space and injecting a carbon dioxide-containing gas into the third accommodating space.

In addition, an elution reactor for eluting calcium ions from a calcium-containing material using an eluting agent to generate a second aqueous solution containing calcium ions (Ca ²⁺ ) and chlorine ions (Cl ^- ); and a secondary battery to which carbon dioxide-containing gas and the second aqueous solution are supplied and produces calcium carbonate (CaCO ₃ ) through a reaction.

Additionally, it relates to a method for producing calcium carbonate using the secondary battery and calcium carbonate production equipment.

The third purpose to solve the above problem is as follows.

a cathode portion including a first aqueous solution contained in a first accommodating space, and a cathode (anode) at least partially submerged in the first aqueous solution; an anode portion including a second aqueous solution contained in a second accommodating space and a metal anode at least partially submerged in the second aqueous solution; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and an ion exchange membrane located in the connecting passage; A power supply device connecting the cathode and anode; And a calcium carbonate generator connected to the first accommodating space and the third accommodating space to generate calcium carbonate (CaCO _{3 (S)} ); When power is supplied to the power supply device, hydrogen gas and calcium carbonate are generated. The purpose is to provide a water electrolysis system that generates electricity.

The fourth purpose to solve the above problem is as follows.

a first electrode unit including a first aqueous solution accommodated in the first accommodating space, and a first electrode at least partially submerged in the first aqueous solution; a second electrode unit including a second aqueous solution accommodated in a second receiving space, and a second electrode at least partially submerged in the second aqueous solution; a first connection portion including a connecting passage connecting the first accommodating space and the second accommodating space, and a cation exchange membrane provided in the connecting passage; a third electrode unit including a third aqueous solution accommodated in a third accommodating space, and a third electrode at least partially submerged in the third aqueous solution; a second connection portion including a connecting passage connecting the second accommodating space and the third accommodating space, and an exchange membrane provided in the connecting passage; The object is to provide a composite secondary battery including a power supply connected to the second electrode and the third electrode.

The first technical solution related to the first objective is as follows.

A secondary battery according to one aspect includes a cathode portion including a first aqueous solution containing potassium hydroxide accommodated in a first accommodating space, and a cathode at least partially submerged in the first aqueous solution; an anode unit including a second aqueous solution containing chlorine ions (Cl-) accommodated in the second accommodating space, and a metal anode at least partially submerged in the second aqueous solution;

a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; and a carbon dioxide treatment unit that communicates with the first accommodation space and includes a first aqueous solution accommodated in the third accommodation space. When discharging, the anode unit oxidizes chlorine ions (Cl) to produce chlorine gas (Cl2). Electrons (e-) are generated, and carbon dioxide gas flows into the first aqueous solution in the third accommodation space, and hydrogen ions (H+) and bicarbonate ions (HCO3-) are generated by the reaction of the first aqueous solution and the carbon dioxide gas. The cathode part is characterized in that hydrogen gas (H2) is generated by combining the hydrogen ions (H+) with the electrons of the cathode.

The carbon dioxide treatment unit may separate un-ionized carbon dioxide gas from the carbon dioxide gas flowing into the first aqueous solution of the third accommodation space to prevent it from being supplied to the cathode unit.

The carbon dioxide treatment unit may separate the non-ionized carbon dioxide gas using a difference in specific gravity from the first aqueous solution.

The carbon dioxide processing unit may collect the non-ionized carbon dioxide gas from an upper portion of the water surface of the first aqueous solution in the third accommodation space.

The carbon dioxide treatment unit is located below the water surface of the first aqueous solution in the third accommodation space and includes an inlet through which carbon dioxide gas flows; and a communication port located below the inlet and formed to communicate with the first accommodating space in the third accommodating space.

The cathode unit may further include a first outlet that is located above the water surface of the first aqueous solution accommodated in the first accommodation space and discharges hydrogen gas generated during discharge.

The carbon dioxide treatment unit may be located above the water surface of the first aqueous solution in the third accommodation space and may further include a second outlet through which the non-ionized carbon dioxide gas is discharged during discharge.

The carbon dioxide processing unit may further include a carbon dioxide circulation supply unit supplying the non-ionized carbon dioxide gas to the first aqueous solution in the third accommodation space.

The second aqueous solution may contain one or more cations selected from the group consisting of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), aluminum (Al), and lithium (Li). .

The second aqueous solution may include seawater.

When the secondary battery is discharged, the cathode portion contains at least one carbonate selected from the group consisting of sodium bicarbonate (NaHCO ₃ ), potassium bicarbonate (KHCO ₃ ), calcium carbonate (CaCO ₃ ), and magnesium carbonate (MgCO ₃ ). can do.

A combined power generation system according to another aspect includes the secondary battery, which generates hydrogen using carbon dioxide as a raw material during a discharge process; and a fuel cell supplied with hydrogen generated from the secondary battery as fuel.

The second technical solution related to the second purpose is as follows.

A secondary battery according to one aspect includes a cathode portion including a first aqueous solution contained in a first accommodating space, and a cathode at least partially submerged in the first aqueous solution;

An anode comprising a second aqueous solution accommodated in a second accommodating space and containing a calcium salt containing calcium ions (Ca ²⁺ ) and chlorine ions (Cl ^- ), and a metal anode at least partially immersed in the second aqueous solution. wealth;

a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; and

It includes a carbon dioxide treatment unit having a first aqueous solution accommodated in a third accommodating space in communication with the first accommodating space, and injecting a carbon dioxide-containing gas into the third accommodating space,

During discharging, the anode unit oxidizes chlorine ions (Cl ^- ) to generate chlorine gas (Cl ₂ ) and electrons (e ^- ), and carbon dioxide gas flows into the first aqueous solution in the third accommodation space, thereby generating the first aqueous solution. Hydrogen ions (H ⁺ ) and bicarbonate ions (HCO ₃ ^- ) are generated by the reaction of the aqueous solution and the carbon dioxide gas, and the cathode unit combines the water (H ₂ O) with the electrons generated at the anode to produce hydroxide ions ( It is characterized by the generation of OH ^- ) and hydrogen gas (H ₂ ).

The first aqueous solution may include one or more compounds selected from the group consisting of KOH and KHCO ₃ .

When the secondary battery is discharged, the cathode unit can produce calcium carbonate ₍ CaCO 3 ) through the reaction of calcium ions (Ca ²⁺ ) that have moved through the cation exchange membrane with hydroxide ions (OH ^- ) and bicarbonate (HCO ₃ ^- ).

According to another aspect, a calcium carbonate production facility includes an elution reactor for eluting calcium ions from a calcium-containing material using an eluent to generate a second aqueous solution containing calcium ions (Ca ²⁺ ) and chlorine ions (Cl ^- ); and a secondary battery to which carbon dioxide-containing gas and the second aqueous solution are supplied, and which generates calcium carbonate (CaCO ₃ ) through a reaction.

When the secondary battery is discharged, the eluent remains in the first accommodation space, and the calcium carbonate (CaCO ₃ ) may be generated in the second accommodation space.

The eluent may be an ammonium salt.

The carbon dioxide-containing gas includes steel exhaust gas, high-purity carbon dioxide, FOG (FINEX off gas), FINEX tail gas (FTG), blast furnace gas (BFG), converter gas, coal-fired power plant exhaust gas, It may be one or more selected from the group consisting of gas power plant off-gas, incinerator off-gas, glass melting off-gas, thermal facility off-gas, petrochemical process off-gas, petrochemical process process gas, pre-/post-combustion off-gas, and gasifier off-gas.

The calcium-containing material may be one or more selected from the group consisting of waste cement, waste concrete, coal ash, fly ash, iron slag, quicklime (CaO), calcium chloride (CaCl ₂ ), wollastonite, limestone, olivine, serpentine, asbestos, and deinked ash. .

A method for producing calcium carbonate according to another aspect includes an elution step of eluting calcium ions from a calcium-containing material using an eluting agent to produce a second aqueous solution; and a calcium carbonate generation step of reacting the carbon dioxide-containing gas and the second aqueous solution with sodium hydroxide (NaOH) generated during discharging of the secondary battery according to claim 1 to produce calcium carbonate (CaCO ₃ ).

The third technical solution related to the third objective is as follows.

A water electrolysis system according to one aspect includes a cathode portion including a first aqueous solution contained in a first accommodating space, and a cathode (anode) at least partially submerged in the first aqueous solution; an anode portion including a second aqueous solution contained in a second accommodating space and a metal anode at least partially submerged in the second aqueous solution; A power supply device connecting the cathode and anode; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and an ion exchange membrane located in the connecting passage; And a calcium carbonate generator connected to the first accommodating space and the third accommodating space to generate calcium carbonate (CaCO _{3 (S)} ); When supplying power to the power supply device, the first accommodating space is connected to the first accommodating space and the third accommodating space. Carbon dioxide gas flows into the electrolyte solution, and hydrogen ions (H ⁺ ) and bicarbonate ions (HCO ₃ ^- ) are generated by the reaction of the first electrolyte solution and the carbon dioxide gas, and the hydrogen ions (H ⁺ ) and the power supply are supplied. It is characterized in that electrons (e ^- ) are combined to generate hydrogen gas (H ₂ ).

The calcium carbonate generating unit includes a reactor that generates calcium carbonate (CaCO _3(S) ); A first inlet connecting the first accommodation space and the reactor and introducing bicarbonate ions (HCO ₃ ^- ) from the first accommodation space into the reactor; A second inlet connected to the reactor and introducing calcium ions (Ca ²⁺ ) into the reactor; and a third inlet that connects the third accommodating space and the reactor and injects the remaining liquid after the calcium carbonate (CaCO _3(S) ) production reaction into the third accommodating space.

The anode may include an oxygen evolution reaction catalyst.

The oxygen evolution reaction catalyst may be one or more selected from the group consisting of metal oxide catalysts, perovskite oxide catalysts, metal sulfide catalysts, metal carbide catalysts, and carbon catalysts.

The metal contained in the oxygen evolution reaction catalyst is selected from the group consisting of Li, Co, Ni, Zn, Fe, Ti, Na, Mn, Cu, Ga, Sn, Cr, W, Ru, Ir, Pt, and Au. There may be at least one type.

The cathode may include carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, and metal thin film.

The cathode may further include a hydrogen evolution reaction catalyst.

The carbon dioxide treatment unit may further include a carbon dioxide treatment unit that communicates with the first accommodation space and includes a third aqueous solution accommodated in the third accommodation space.

The carbon dioxide treatment unit may separate unionized carbon dioxide gas from the carbon dioxide gas flowing into the third accommodation space from the third aqueous solution and prevent it from being supplied to the anode unit.

The carbon dioxide treatment unit may separate the non-ionized carbon dioxide gas using a difference in specific gravity from the third aqueous solution.

The carbon dioxide treatment unit is located below the water surface of the third aqueous solution in the third accommodation space and includes an inlet through which carbon dioxide gas flows. and a communication port located below the inlet and formed to communicate with the first accommodating space in the third accommodating space.

The carbon dioxide treatment unit may be located above the water surface of the third aqueous solution in the third accommodation space and may further include a second outlet through which the non-ionized carbon dioxide gas is discharged during discharge.

The carbon dioxide treatment unit may further include a carbon dioxide circulation supply unit that resupplies the non-ionized carbon dioxide gas to the third aqueous solution in the third accommodation space.

The first or second aqueous solution may be an alkaline aqueous solution containing alkaline metal ions.

Alkaline metal ions in the second accommodation space may move to the first accommodation space through the ion exchange membrane.

The fourth technical solution related to the fourth objective is as follows.

A composite secondary battery according to one aspect includes a first electrode portion including a first aqueous solution accommodated in a first accommodating space, and a first electrode at least partially submerged in the first aqueous solution; a second electrode unit including a second aqueous solution accommodated in a second receiving space, and a second electrode at least partially submerged in the second aqueous solution; a first connection portion including a connecting passage connecting the first accommodating space and the second accommodating space, and a cation exchange membrane provided in the connecting passage; a third electrode unit including a third aqueous solution accommodated in a third accommodating space, and a third electrode at least partially submerged in the third aqueous solution; a second connection portion including a connecting passage connecting the second accommodating space and the third accommodating space, and an exchange membrane provided in the connecting passage; And a power supply connected to the second electrode and the third electrode; and, when discharging, the first electrode unit allows carbon dioxide gas to flow into the first aqueous solution in the first accommodation space so that the first aqueous solution and the carbon dioxide Hydrogen ions (H ⁺ ) and bicarbonate ions (HCO ₃ ^- ) are generated by the reaction of the gas, the second electrode unit generates electrons (e ^- ) through an oxidation reaction, and the first electrode unit generates the hydrogen ions ( It is characterized in that hydrogen gas (H ₂ ) is generated by combining H ⁺ ) and electrons (e ^- ) generated in the second electrode portion.

The composite secondary battery includes a reactor that generates calcium carbonate (CaCO _3(S) ); A first inlet connecting the first accommodation space and the reactor and introducing bicarbonate ions (HCO ₃ ^- ) from the first accommodation space into the reactor; A second inlet connected to the reactor and introducing calcium ions (Ca ²⁺ ) into the reactor; And a third inlet connecting the third receiving space and the reactor and injecting the remaining liquid after the calcium carbonate (CaCO _{3 (S)} ) production reaction into the third receiving space. Calcium carbonate (CaCO _{3 (S)} ) comprising a. It may include a creation unit.

The composite secondary battery may further include a carbon dioxide treatment unit that communicates with the first accommodating space and includes a fourth aqueous solution accommodated in the fourth accommodating space.

The carbon dioxide treatment unit may separate unionized carbon dioxide gas from the fourth aqueous solution and prevent it from being supplied to the first electrode unit.

The carbon dioxide treatment unit is located below the water surface of the fourth aqueous solution in the fourth accommodation space and includes an inlet through which carbon dioxide gas flows; and a communication port located below the inlet and formed to communicate with the first accommodating space in the fourth accommodating space.

The first electrode unit may be located above the water surface of the first aqueous solution accommodated in the first accommodation space and may further include a first outlet for discharging hydrogen gas generated during discharge.

The carbon dioxide treatment unit may be located above the water surface of the fourth aqueous solution in the fourth accommodation space and may further include a second outlet through which the non-ionized carbon dioxide gas is discharged during discharge.

The carbon dioxide treatment unit may further include a carbon dioxide circulation supply unit that re-supplies the non-ionized carbon dioxide gas to the fourth aqueous solution in the fourth accommodation space.

When the third electrode unit is supplied with power from a power supply device, an oxygen evolution reaction (OER) and a chlorine evolution reaction (CER) may occur.

The third electrode unit may be located above the water surface of the third aqueous solution accommodated in the third accommodation space and may further include a second outlet for discharging oxygen gas and chlorine gas generated when power is supplied to the power supply device.

The third electrode unit may further include a residual liquid circulation supply unit that re-supplies the remaining liquid after reaction to the fourth aqueous solution in the fourth receiving space when power is supplied to the power supply device.

The effects of the first invention in relation to the first technical solution are as follows.

The secondary battery according to one embodiment has the advantage of being able to produce various carbonates and hydrogen, an eco-friendly fuel, with high purity using seawater, a sustainable raw material, and carbon dioxide, a greenhouse gas.

The effects of the present invention are not limited to the effects mentioned above. The effects of the present invention should be understood to include all effects that can be inferred from the following description.

The effects of the second invention related to the second technical solution are as follows.

A secondary battery according to one aspect can produce hydrogen with high purity, and a calcium carbonate production facility using the secondary battery has the advantage of being able to produce calcium carbonate, a carbonate, with high purity.

The effects of the third invention related to the third technical solution are as follows.

The water electrolysis system according to one aspect has the advantage of being able to produce not only oxygen and chlorine, but also hydrogen and calcium carbonate with high purity.

The effects of the fourth invention related to the fourth technical solution are as follows.

A composite secondary battery according to one aspect has the advantage of being able to produce not only oxygen and chlorine, but also hydrogen and calcium carbonate with high purity.

In addition, the composite secondary battery according to one aspect can regenerate the metal of the electrode consumed by discharge according to the application of power to the power supply device, so it is possible to economically and efficiently produce calcium carbonate through the application of power to the power supply device without replacing the metal. There are advantages to this.

Figure 1 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to an embodiment of the present invention.

Figure 2 is a schematic diagram showing the discharge process of a secondary battery using carbon dioxide according to another embodiment.

Figure 3 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to an embodiment of the present invention.

Figure 4 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to another embodiment.

Figure 5 is a schematic diagram schematically showing a calcium carbonate manufacturing facility using a secondary battery according to another embodiment.

Figure 6 is a graph showing the XRD analysis results of calcium carbonate (CaCO3) produced as a result of operating the calcium carbonate production facility manufactured according to Example 1.

Figure 7 is a schematic diagram showing the water electrolysis process of a water electrolysis system according to an embodiment.

Figure 8 is a schematic diagram showing the water electrolysis process of a water electrolysis system according to another embodiment.

Figure 9 is a schematic diagram showing the discharge process of a composite secondary battery using carbon dioxide according to an embodiment.

Figure 10 is a schematic diagram showing the discharge process of a composite secondary battery using carbon dioxide according to another embodiment.

The above objects, other objects, features and advantages will be easily understood through the following preferred embodiments in conjunction with the accompanying drawings. However, it is not limited to the embodiments described here and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content will be thorough and complete and the technical ideas can be sufficiently conveyed to those skilled in the art.

While describing each drawing, similar reference numerals are used for similar components. In the attached drawings, the dimensions of the structures are enlarged from the actual size for clarity of the present invention. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof. Additionally, when a part of a layer, membrane, region, plate, etc. is said to be “on” another part, this includes not only being “directly above” the other part, but also cases where there is another part in between. Conversely, when a part of a layer, membrane, region, plate, etc. is said to be "underneath" another part, this includes not only being "immediately below" the other part, but also cases where there is another part in between.

Unless otherwise specified, all numbers, values, and/or expressions used herein expressing quantities of components, reaction conditions, polymer compositions, and formulations are intended to represent, among other things, how such numbers inherently occur in obtaining such values. Since they are approximations reflecting the various uncertainties of measurement, they should be understood in all cases as being qualified by the term "approximately". Additionally, where a numerical range is disclosed herein, such range is continuous and, unless otherwise indicated, includes all values from the minimum to the maximum of such range inclusively. Furthermore, when such range refers to an integer, all integers from the minimum value up to and including the maximum value are included, unless otherwise indicated.

In this specification, when a range is stated for a variable, the variable will be understood to include all values within the stated range, including the stated endpoints of the range. For example, the range "5 to 10" includes the values 5, 6, 7, 8, 9, and 10, as well as any subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc. It will be understood that it also includes any values between integers that fall within the scope of the stated range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, and 6.5 to 9, etc. Also, for example, the range "10% to 30%" includes values such as 10%, 11%, 12%, 13%, etc. and all integers up to and including 30%, as well as 10% to 15%, 12% to 12%, etc. It will be understood that it includes any subranges, such as 18%, 20% to 30%, etc., and any value between reasonable integers within the range of the stated range, such as 10.5%, 15.5%, 25.5%, etc.

Although many means have been provided to reduce conventional greenhouse gas emissions, there is a need to develop a new concept of sustainable breakthrough technology that captures, stores, and utilizes carbon dioxide more efficiently. In addition, in order to reduce carbon dioxide emissions and lower the cost of producing calcium carbonate, there was a problem that calcium components should not be supplied to limestone and a calcium source that does not bind to carbon dioxide should be used.

Accordingly, the present inventors conducted intensive research to solve the above problem, and as a result, a cathode portion including a first aqueous solution containing potassium hydroxide accommodated in the first accommodation space, and a cathode at least partially submerged in the first aqueous solution; an anode portion including a second aqueous solution containing chlorine ions (Cl ^- ) accommodated in the second accommodating space, and a metal anode at least partially immersed in the second aqueous solution; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; In the case of a secondary battery including a carbon dioxide treatment unit that communicates with the first accommodation space and includes a first aqueous solution accommodated in the third accommodation space, when discharging, the anode unit oxidizes chlorine ions (Cl ^- ) into chlorine. Gas (Cl ₂ ) and electrons (e ^- ) are generated, and carbon dioxide gas flows into the first aqueous solution in the third accommodation space to generate hydrogen ions (H ⁺ ) and It was discovered that bicarbonate ions (HCO ₃ ^- ) are generated, and the cathode unit combines the hydrogen ions (H ⁺ ) with the electrons of the cathode to generate high purity hydrogen gas (H ₂ ).

In addition, as a result of intensive research by the present inventors to solve the above problem, the present inventors have found: a cathode portion including a first aqueous solution included in the first accommodation space, and a cathode at least partially submerged in the first aqueous solution; An anode comprising a second aqueous solution accommodated in a second accommodating space and containing a calcium salt containing calcium ions (Ca ²⁺ ) and chloride ions (Cl-), and a metal anode at least partially immersed in the second aqueous solution. wealth; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; And a carbon dioxide treatment unit provided with a first aqueous solution accommodated in a third accommodating space in communication with the first accommodating space and injecting a carbon dioxide-containing gas into the third accommodating space. In the case of a secondary battery comprising a high-purity hydrogen gas (H In addition to producing ₂ ), the present invention was completed by discovering that the calcium carbonate production facility using the secondary battery can produce calcium carbonate, a carbonate, with high purity.

In addition, as a result of intensive research by the present inventors to solve the above problem, the present inventors have found: a cathode portion including a first aqueous solution contained in the first accommodating space, and a cathode (anode) at least partially submerged in the first aqueous solution; an anode portion including a second aqueous solution contained in a second accommodating space and a metal anode at least partially submerged in the second aqueous solution; a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and an ion exchange membrane located in the connecting passage; A power supply device connecting the cathode and anode; In the case of a water electrolysis system including a calcium carbonate generator connected to the first accommodation space and the third accommodation space to generate calcium carbonate (CaCO _{3 (S)} ), when power is supplied to the power supply device, oxygen and chlorine, etc., as well as producing hydrogen and calcium carbonate with high purity.

In addition, as a result of intensive research by the present inventors to solve the above problem, the present inventors have found: a first electrode unit including a first aqueous solution accommodated in the first accommodating space, and a first electrode at least partially submerged in the first aqueous solution; a second electrode unit including a second aqueous solution accommodated in a second receiving space, and a second electrode at least partially submerged in the second aqueous solution; a first connection portion including a connecting passage connecting the first accommodating space and the second accommodating space, and a cation exchange membrane provided in the connecting passage; a third electrode unit including a third aqueous solution accommodated in a third accommodating space, and a third electrode at least partially submerged in the third aqueous solution; a second connection portion including a connecting passage connecting the second accommodating space and the third accommodating space, and an exchange membrane provided in the connecting passage; In the case of a composite secondary battery including a power supply connected to the second electrode and the third electrode, not only can hydrogen be produced with high purity, but also oxygen and hydrogen can be produced, and calcium carbonate can be produced with high purity. It was discovered that it was effective and a composite secondary battery was completed.

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

Figure 1 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to an embodiment of the present invention. Referring to FIG. 1, the secondary battery 100 according to an embodiment of the present invention includes a cathode portion 110, an anode portion 150, and a connection portion connecting the cathode portion 110 and the anode portion 150. 190). The secondary battery 100 can produce hydrogen (H ₂ ), an eco-friendly fuel, by using carbon dioxide gas (CO2), a greenhouse gas, as a raw material during the discharge process.

The cathode portion 110 may include a first aqueous solution 115 contained in the first receiving space 111 and a cathode 118 that is at least partially submerged in the first aqueous solution 115.

The first aqueous solution 115 may be an alkaline aqueous solution (in this example, CO ₂ dissolved in a strong basic solution of 1M KOH is used), seawater, tap water, distilled water, etc., and preferably, dissolves carbon dioxide. It may be an alkaline aqueous solution for ease of use.

According to one embodiment, the first aqueous solution 115 may be a strongly basic solution of 1M KOH, and may be used by further eluting CO ₂ during subsequent discharge.

The cathode 118 may have one side in contact with the first electrolyte, but preferably may be positioned so that at least a portion of the cathode 118 is submerged in the first electrolyte.

The cathode 118 may be a cathode for forming an electric circuit, and is not particularly limited as long as it contains a material that can reduce electrons at the cathode, for example, carbon paper, carbon fiber, carbon felt, It may be one or more selected from the group consisting of carbon cloth, metal foam, and metal thin film.

The cathode 118 may further include a catalyst within the cathode to promote the reduction reaction. Specifically, it may be a hydrogen evolution reaction catalyst, for example, one or more types selected from the group consisting of platinum catalysts, carbon-based catalysts, carbon-metal composite catalysts, and perovskite oxide catalysts. It may include, and preferably, may further include a platinum catalyst with the highest hydrogen generation reaction activity.

The cathode portion 110 may further include a first inlet 112, a first outlet 113, and a first connector 114 that communicate with the first receiving space 111.

The first inlet 112 may be located at the lower part of the first receiving space 111 so as to be located below the water surface of the first aqueous solution 115. The first outlet 113 may be located at the upper part of the first receiving space 111 so as to be above the water surface of the first aqueous solution 115. Carbon dioxide, which is used as a raw material during the discharge process, flows into the first receiving space 111 through the first inlet 112, and when necessary, the first aqueous solution 115 can also flow in. Gas generated during charging and discharging can be discharged to the outside through the first outlet 113. Although not shown, the inlet 112 and outlet 113 may be selectively opened and closed at appropriate times by a valve or the like during charging and discharging. The first connector 114 is located below the water surface of the first aqueous solution 115, and a connector 190 is connected to the first connector 114. A carbon dioxide elution reaction may occur in the cathode portion 110 during the discharge process.

The anode unit 150 may include a second aqueous solution 155 contained in the second receiving space 151 and an anode 158 that is at least partially submerged in the second aqueous solution 155.

The second aqueous solution 155 may be seawater, tap water, distilled water, etc., and preferably contains chlorine ions (Cl ^- ) as anions, potassium (K), sodium (Na), calcium (Ca), It may be a neutral solution that contains one or more cations selected from the group consisting of magnesium (Mg), aluminum (Al), and lithium (Li), thereby suppressing the oxygen evolution reaction, which is a competing reaction.

According to one embodiment, the second aqueous solution 155 may be a 1M KCl solution or seawater containing a compound containing chloride ions (Cl ^- ).

The anode 158 may have one side in contact with the second electrolyte, but preferably may be positioned so that at least a portion of the anode 158 is submerged in the second electrolyte.

The anode 158 is a metal anode that forms an electric circuit, and oxidizes chlorine ions (Cl ^- ) to generate chlorine gas (Cl ₂ ) and electrons (e ^- ). ; CER) including catalysts, e.g., the group consisting of metal oxide catalysts, perovskite oxide catalysts, metal sulfide catalysts (e.g. NiS), metal carbide catalysts (e.g. WC), and carbon catalysts. It may be selected from, and more specifically, it may be selected from the group consisting of metal oxide catalysts and perovskite oxide catalysts. The metals of the metal oxide catalyst, metal sulfide catalyst, and metal carbide catalyst include Li, Co, Ni, Zn, Fe, Ti, Na, Mn, Cu, Ga, Sn, Cr, W, Ru, Ir, Pt, and Au. It may be at least one type selected from the group consisting of. Specifically, the metal oxide catalyst may be an oxide of a metal selected from the group consisting of Co, Ni, Mn, Ru, and Ir.

A second connector 154 communicating with the second receiving space 151 is formed in the anode portion 150. The second connector 154 is located below the water surface of the second aqueous solution 155, and the connector 190 may be connected to the second connector 154.

The connection portion 190 may include a connection passage 191 connecting the cathode portion 110 and the anode portion 150, and a cation exchange membrane 192 installed inside the connection passage 191.

The connection passage 191 extends between the first connector 114 formed in the cathode portion 110 and the second connector 154 formed in the anode portion 150 to form the first receiving space of the cathode portion 110 ( 111 and the second accommodation space 151 of the anode unit 150 may be connected. A cation exchange membrane 192 may be installed inside the connection passage 191.

The cation exchange membrane 192 may be installed to block the interior of the connection passage 191. The cation exchange membrane (membrane) 192 allows only the movement of ions between the cathode portion 110 and the anode portion 150 to resolve ion imbalance occurring during the discharge process. Preferably, the second aqueous solution ( Cations contained in 155) may move to the first aqueous solution 115.

According to one embodiment, the membrane capable of moving cations to the cation exchange membrane 192 is Nafion (Nafion 117, 212, 211, etc.), a fluororesin-based cation exchange membrane developed by DuPont in the United States. can be used.

Figure 2 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to another embodiment. Referring to FIG. 2, the secondary battery 100a includes a cathode portion 110, an anode portion 150, a connection portion 190 connecting the cathode portion 110 and the anode portion 150, a carbon dioxide treatment portion 120, and a carbon dioxide It may include a circulation supply unit 130 and a connection pipe 140 that communicates the cathode unit 110 and the carbon dioxide treatment unit 120.

Among the content related to the cathode portion 110, the anode portion 150, and the connection portion 190, content that overlaps with the content described in the embodiment shown in FIG. 1 may be omitted.

The carbon dioxide treatment unit 120 may be accommodated in the third accommodation space 121 and may be provided with a first aqueous solution 115 that is the same as the first aqueous solution 115 of the cathode unit 110.

The carbon dioxide treatment unit 120 includes a second inlet 122 through which carbon dioxide flows into the third accommodation space 121, a communication port 123 to which the connection pipe 140 is connected, and an upper portion of the third accommodation space 121. It may include a second outlet 124 located at.

The second inlet 122 may be located above the communication port 123 in the third receiving space 121, and may be located below the second outlet 124 and the water surface of the first aqueous solution 115. Carbon dioxide gas used as fuel during the discharge process can flow into the third receiving space 121 through the second inlet 122, and the first aqueous solution 115 is also supplied through the second inlet 122 as needed. It can be.

The second outlet 124 is located above the water level of the second inlet 122 and the first aqueous solution 115 in the third accommodation space 121. Carbon dioxide gas that is not dissolved in the first aqueous solution 115 and thus not ionized in the third accommodation space 121 through the second outlet 124 floats to the top due to the difference in specific gravity and is finally discharged to the outside. Carbon dioxide gas discharged through the second outlet 124 may be supplied to the second inlet 122 through the carbon dioxide circulation supply unit 130.

This has the advantage of increasing the purity of hydrogen (H ₂ ) gas discharged from the first outlet. In other words, the existing method did not include a separate carbon dioxide treatment unit, so there was a disadvantage in that unionized carbon dioxide gas and hydrogen gas generated from the secondary battery were mixed and discharged, lowering the purity. However, the secondary battery according to another embodiment has a carbon dioxide treatment unit, so that the carbon dioxide gas flowing into the third accommodation space is not dissolved in the first aqueous solution and thus the unionized carbon dioxide gas cannot move to the first accommodation space of the cathode unit. There is an advantage in that high purity hydrogen gas can be obtained by separately discharging the non-ionized carbon dioxide gas through the second outlet 124, which is different from the first outlet through which hydrogen gas generated from the secondary battery is discharged.

Meanwhile, the second inlet 122 and the first outlet 113 may be selectively opened and closed at appropriate times by a valve or the like during charging and discharging.

The communication port 123 is located below the second inlet 122 in the third accommodation space 121, and a connection pipe 140 may be connected to the communication port 123. The third accommodating space 121 may be in communication with the first accommodating space 111 through the communication port 123.

The connection pipe 140 may connect the first inlet 112 of the first accommodation space 111 and the communication port 123 of the third accommodation space 121. The first accommodating space 111 and the third accommodating space 121 may be communicated through the connecting passage 141 formed inside the connecting pipe 140.

The carbon dioxide circulation supply unit 130 may circulate the carbon dioxide gas discharged through the second outlet 224 to the second inlet 122 and re-supply it.

That is, among the carbon dioxide gas that flows into the third accommodation space 121 of the carbon dioxide processing unit 120 through the second inlet 122, the carbon dioxide gas that is not dissolved in the first aqueous solution 115 and thus is not ionized is in the cathode unit 110. It fails to move to the first accommodating space 111 and rises, collects in the space above the water surface of the first aqueous solution 115 in the third accommodating space 121, and is then discharged through the second outlet 124 and the second outlet 124. The carbon dioxide gas discharged through is supplied to the third receiving space 121 through the second inlet 122 by the carbon dioxide circulation supply unit 130 and recycled.

Therefore, the secondary battery according to another embodiment has the advantage of increasing the energy efficiency of the battery because it can supply non-ionized carbon dioxide gas to the second inlet 122 through the carbon dioxide circulation supply unit 130.

Now, the discharging process of the secondary battery 100 described above in terms of configuration will be described. Figure 1 or Figure 2 shows the discharging process of the secondary battery 100. Referring to this, carbon dioxide as a raw material for hydrogen production is injected into the first aqueous solution 115 through the first inlet 112, and a chemical elution reaction of carbon dioxide occurs in the cathode unit 110 as shown in the following [Reaction Formula 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 undergoes a spontaneous chemical reaction with water (H ₂ O) of the first aqueous solution 115 to form hydrogen cations (H ⁺ ) and bicarbonate ( HCO ₃ ^- ) can be produced.

Additionally, an electrical reaction occurs in the cathode unit 110 as shown in [Reaction Formula 2].

[Scheme 2]

2H ⁺ (aq) + 2e ^- → H ₂ (g)

That is, in the cathode part 110, hydrogen positive ions (H+) receive electrons (e ^- ) and hydrogen (H ₂ ) gas is generated. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 113.

In addition, a complex hydrogen generation reaction occurs in the cathode unit 110 as shown in [Reaction Formula 3].

[Scheme 3]

2H ₂ O(l) + 2CO ₂ (g) + 2e ^- → H ₂ (g) + 2HCO ₃ ^- (aq)

As a result, the generated bicarbonate (HCO ₃ ^- ) reacts with cations moving from the anode unit 150 through the connection unit 190 to produce sodium bicarbonate (NaHCO ₃ ), potassium bicarbonate (KHCO ₃ ), and calcium carbonate (CaCO ₃ ), and magnesium carbonate (MgCO ₃ ). One or more carbonates selected from the group consisting of may be produced.

And, in the anode unit 150, the anode 158 undergoes an oxidation reaction as shown in [Reaction Formula 4] through a chlorine generation reaction.

[Scheme 4]

2Cl ^- (aq) → Cl ₂ (g) + 2e ^-

As a result, as can be seen through the above reaction equations, during discharge, chlorine ions (Cl ^- ) are oxidized in the metal anode 158 to generate chlorine gas (Cl ₂ ) and electrons (e ^- ), and the anode part ( Cations contained in the second aqueous solution 155 of 150 pass through the cation exchange membrane 192 and move to the first aqueous solution 115 of the cathode unit 110, thereby preventing changes in the first aqueous solution due to carbon dioxide supply. there is. Meanwhile, hydrogen ions generated by carbon dioxide eluted from the first aqueous solution 115 may receive electrons from the cathode 118, be reduced to hydrogen gas, and be discharged through the first outlet 113.

In addition, according to another embodiment, a composite power generation system including the above-described secondary battery and a fuel cell supplied as fuel with hydrogen generated from the secondary battery can be provided.

According to another embodiment, the hydrogen fuel cell can generate water and electrical energy through a chemical reaction between hydrogen and oxygen. Specifically, the hydrogen fuel cell may be a solid oxide fuel cell (SOFC).

Conventionally, hydrogen fuel cells have many advantages in terms of environmental friendliness, but they must be supplied with hydrogen extracted through methane-steam reforming. However, the combined power generation system according to another embodiment has the advantage that efficiency can be significantly improved by constructing a hydrogen fuel cell and a secondary battery as one system and receiving hydrogen gas generated from the secondary battery as fuel. There is.

Figure 3 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to an embodiment of the present invention. Referring to FIG. 3, the secondary battery 100 according to an embodiment of the present invention includes a cathode portion 110, an anode portion 150, and a connection portion connecting the cathode portion 110 and the anode portion 150. 190). The secondary battery 100 uses carbon dioxide gas (CO ₂ ), a greenhouse gas, as a raw material during the discharge process to produce hydrogen (H ₂ ), an eco-friendly fuel, and calcium carbonate (CaCO ₃ ), a carbonate.

The first aqueous solution 115 may be a neutral aqueous solution, a slightly alkaline aqueous solution, seawater, tap water, distilled water, etc., and may preferably be a slightly alkaline aqueous solution with a pH of about 10.

According to one embodiment, the first aqueous solution 115 may be a strongly basic solution of 1M NaOH, and during subsequent discharge, CO ₂ may be further dissolved and may be a weakly alkaline solution of 1M KHCO ₃ .

The cathode 118 may further include a catalyst within the cathode to promote the reduction reaction. Specifically, it may be a hydrogen evolution reaction catalyst, for example, one or more types selected from the group consisting of platinum catalysts, carbon-based catalysts, carbon-metal composite catalysts, and perovskite oxide catalysts. It may include, and preferably may further include, a platinum catalyst having excellent hydrogen generation activity at various pH.

The second aqueous solution 155 may be seawater, tap water, distilled water, etc., and preferably contains chlorine ions (Cl ^- ) as anions and calcium ions (Ca ²⁺ ) that can produce calcium carbonate. It may be a solution in which carbon chloride (CaCl ₂ ) is dissolved.

According to one embodiment, the second aqueous solution 155 may be a carbon chloride (CaCl ₂ ) solution dissolved in a concentration of 0.1M to 2.0M.

The anode 158 is an oxidizing electrode forming an electric circuit, and is not particularly limited as long as it can oxidize chlorine ions (Cl ^- ) to generate chlorine gas (Cl ₂ ) and electrons (e ^- ), and is a chlorine generation reaction catalyst, For example, it may include one or more selected from the group consisting of a metal oxide catalyst, a perovskite oxide catalyst, a metal sulfide catalyst, a metal carbide catalyst, and a carbon catalyst, and preferably, the chlorine generation The reaction catalyst may be at least one selected from the group consisting of Li, Co, Ni, Zn, Fe, Ti, Na, Mn, Cu, Ga, Sn, Cr, W, Ru, Ir, Pt, and Au.

The cation exchange membrane 192 may be installed to block the interior of the connection passage 191. The cation exchange membrane (membrane) 192 allows only the movement of ions between the cathode portion 110 and the anode portion 150 to resolve ion imbalance occurring during the discharge process. Preferably, the second aqueous solution ( Calcium ions (Ca ²⁺ ) contained in 155) may move to the first aqueous solution 115.

According to one embodiment, as a membrane capable of moving cations to the cation exchange membrane 192, Nafion (Nafion 212, 117, etc.), a fluororesin-based cation exchange membrane developed by DuPont in the United States, is used. You can.

Figure 4 is a schematic diagram showing the discharging process of a secondary battery using carbon dioxide according to another embodiment. Referring to FIG. 4, the secondary battery 100a includes a cathode portion 110, an anode portion 150, a connection portion 190 connecting the cathode portion 110 and the anode portion 150, a carbon dioxide treatment portion 120, and a carbon dioxide It may include a circulation supply unit 130 and a connection pipe 140 that communicates the cathode unit 110 and the carbon dioxide treatment unit 120.

Among the content related to the cathode portion 110, the anode portion 150, and the connection portion 190, content that overlaps with the content described in the embodiment shown in FIG. 3 may be omitted.

The connection pipe 140 may connect the first inlet 112 of the first accommodation space 111 and the communication port 123 of the third accommodation space 121. The first accommodating space 111 and the third accommodating space 121 may be communicated through a connection passage formed inside the connecting pipe 140.

The carbon dioxide circulation supply unit 130 may circulate the carbon dioxide gas discharged through the second outlet 124 to the second inlet 122 and re-supply it.

Now, the discharging process of the secondary battery 100 described above in terms of configuration will be described. Figure 3 or Figure 4 shows the discharging process of the secondary battery 100. Referring to this, carbon dioxide as a raw material for hydrogen production is injected into the first aqueous solution 115 through the first inlet 112, and a chemical elution reaction of carbon dioxide occurs in the cathode unit 110 as shown in the following [Reaction Formula 5].

[Scheme 5]

H ₂ O(l) + CO ₂ (g) → H ⁺ (aq) + HCO ₃ ^- (aq)

Meanwhile, an electrical reaction occurs in the cathode unit 110 as shown in [Reaction Formula 6].

[Scheme 6]

2H ₂ O + 2e ^- →2OH ^- + H ₂ (g)

Next, calcium carbonate can be produced at high concentration through a chemical reaction as shown in [Reaction Formula 7].

[Scheme 7]

Ca ²⁺ + OH ^- + HCO ₃ ^- → CaCO _3(S) + H ₂ O

That is, in the cathode unit 110, water (H ₂ O) receives electrons (e ^- ) and generates hydrogen (H ₂ ) gas and hydroxide ions (OH ^- ). Meanwhile, hydroxide ions (OH ^- ) generated from water (H ₂ O) and bicarbonate (HCO ₃ ^- ) generated from carbon dioxide react with calcium ions (Ca ²⁺ ) that have moved through the cation exchange membrane to form calcium carbonate ( CaCO ₃ ) can be produced.

At this time, hydroxide ions (OH ^- ) may remain in the first accommodation space and may be reintroduced through a circulation process.

Meanwhile, the hydrogen cation (H+) receives electrons (e ^- ) and generates hydrogen (H ₂ ) gas. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 113.

And, in the anode unit 150, an oxidation reaction such as chlorine generation reaction occurs in the anode 158 as shown in [Reaction Formula 8].

[Scheme 8]

2Cl ^- (aq) → Cl ₂ (g) + 2e ^-

As a result, as can be seen through the above reaction equations, during discharge, chlorine ions (Cl ^- ) are oxidized in the metal anode 158 to generate chlorine gas (Cl ₂ ) and electrons (e ^- ), and the anode part ( Cations contained in the second aqueous solution 155 of 150 pass through the cation exchange membrane 192 and move to the first aqueous solution 115 of the cathode unit 110, thereby preventing changes in the first aqueous solution due to carbon dioxide supply. there is.

Meanwhile, hydrogen ions generated by carbon dioxide eluted from the first aqueous solution 115 may receive electrons from the cathode 118, be reduced to hydrogen gas, and be discharged through the first outlet 113.

With reference to this, the calcium carbonate production facility includes an elution reactor that elutes calcium ions from a calcium-containing material using an eluent to produce a second aqueous solution containing calcium ions (Ca ²⁺ ) and chloride ions (Cl ^- ); and a secondary battery to which carbon dioxide-containing gas and the second aqueous solution are supplied, and which generates calcium carbonate (CaCO ₃ ) through a reaction.

The elution reactor is supplied with an eluent and a calcium-containing material, and calcium ions are eluted from the calcium-containing material by the eluent to produce an aqueous calcium salt solution, preferably calcium ions (Ca ²⁺ ) and chloride ions (Cl ^- ). A second aqueous solution containing The eluting agent reacts with the calcium-containing material and contributes to eluting the calcium contained in the calcium-containing material in the form of calcium ions (Ca ²⁺ ). The type is not particularly limited, but may be an ammonium salt. The ammonium is preferably, for example, at least one selected from the group consisting of ammonium chloride, ammonium nitrate, and ammonium acetate.

The calcium-containing material is not particularly limited as long as it is a material capable of eluting calcium ions using an eluent, but for example, waste cement, waste concrete, coal ash, fly ash, iron slag, low-grade quicklime (CaO), calcium chloride (CaCl ₂ ), it may be one or more selected from the group consisting of wollastonite, limestone, olivine, serpentine, asbestos, and deinked ash.

According to one embodiment, when ammonium chloride is used as an eluent to elute calcium ions contained in iron slag, calcium salt aqueous solution containing calcium ions (Ca ²⁺ ) and chloride ions (Cl ^- ) is obtained according to the following reaction equation 9: A second aqueous solution can be produced.

[Scheme 9]

Steel slag + NH ₄ Cl → CaCl ₂ + NH ₄ OH

The generated second aqueous solution can be supplied to the fuel cell, and in addition to the fuel cell, carbon dioxide-containing gas can be supplied to the fuel cell.

In particular, the sodium bicarbonate and calcium carbonate production facility according to another embodiment has the advantage of being able to ultimately produce calcium carbonate at a high concentration by directly supplying hydroxide ions generated by the fuel cell reaction without the need to additionally supply sodium hydroxide. There is.

In other words, there is no need to supply additional sodium hydroxide, which not only reduces costs and increases calcium carbonate production efficiency, but also the eluent remains in the first accommodation space of the fuel cell, and the calcium carbonate (CaCO- ₃ ) is stored in the second accommodation space. Since it is produced in space, it has the advantage of being able to obtain high yields of calcium carbonate (CaCO- ₃ ) without containing impurities such as solvents.

Meanwhile, pure carbon dioxide can be used as the carbon dioxide-containing gas, and any gas containing carbon dioxide can also be suitably used, such as industrial by-product gas or power plant exhaust gas. For example, steel exhaust gas, high purity carbon dioxide, FOG (FINEX off gas), FINEX tail gas (FTG), blast furnace gas (BFG), converter gas, coal power plant exhaust gas, gas power plant. It may be one or more selected from the group consisting of flue gas, incinerator flue gas, glass melting flue gas, thermal facility flue gas, petrochemical process flue gas, petrochemical process process gas, pre-/post-combustion flue gas, and gasifier flue gas.

According to one embodiment, carbon dioxide-containing gas may be introduced into the third receiving space in the carbon dioxide treatment unit of the secondary battery using steel exhaust gas and high purity carbon dioxide.

The secondary battery can produce calcium carbonate, a high value-added material, at high concentration, and calcium carbonate, a solid material, can be recovered using a solid-liquid separation device (not shown).

Additionally, according to another embodiment, a method for producing calcium carbonate can be provided using a calcium carbonate production facility using a secondary battery.

Specifically, an elution step of eluting calcium ions from a calcium-containing material using an eluting agent to generate a second aqueous solution; and a calcium carbonate generation step of reacting the carbon dioxide-containing gas and the second aqueous solution with sodium hydroxide (NaOH) generated during discharge of the secondary battery to produce calcium carbonate (CaCO ₃ ).

At this time, if any content explaining the manufacturing method overlaps with the content described in the secondary battery or calcium carbonate manufacturing facility, it can be omitted.

in other words. When producing calcium carbonate using the calcium carbonate production facility according to another embodiment, there is an advantage in that calcium carbonate, a carbonate, can be produced with high purity.

The present invention will be described in more detail through examples below. The following examples are merely examples to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

실시예 1 : 탄산칼슘 제조 설비를 이용하여 생성된 탄산칼슘 순도 및 고체상 확인Example 1: Confirmation of purity and solid phase of calcium carbonate produced using calcium carbonate production equipment

A second aqueous solution of 1M calcium chloride (CaCl ₂ ) was prepared using calcium chloride (CaCl ₂ ) as a calcium-containing material and ammonium chloride as an eluent, and supplied to the second receiving space of the anode part of the fuel cell. Meanwhile, carbon dioxide is supplied to 1M KOH, the first aqueous solution contained in the first accommodation space of the cathode part of the fuel cell, so that carbon dioxide is dissolved in the first aqueous solution and 1M potassium hydrogen carbonate (KHCO ₃ ), which is a saturated solution in a slightly alkaline environment, is added. A calcium carbonate manufacturing facility was manufactured using the solution.

Next, after operating the manufactured calcium carbonate manufacturing facility at 100 mA for about 250 min, the purity and phase of the calcium carbonate (CaCO ₃ ) generated in the cathode part was analyzed using XRD (X-ray diffraction) analysis, and the results were obtained. is shown in Figure 6.

Specifically, Figure 6 is a graph showing the XRD analysis results of calcium carbonate (CaCO ₃ ) produced as a result of operating the calcium carbonate production facility manufactured according to Example 1.

Referring to FIG. 6, the crystalline phase of calcium carbonate (CaCO ₃ ) produced through the calcium carbonate production facility manufactured above was confirmed, and it was also confirmed that more than 99% of the solid phase of calcium carbonate was formed in the form of calcite.

Figure 7 is a schematic diagram showing the water electrolysis process of a water electrolysis system according to an embodiment. Referring to FIG. 7, a cathode portion 110 including a first aqueous solution 115 accommodated in the first accommodating space 111, and a cathode 118 at least partially submerged in the first aqueous solution 115; An anode portion 150 including a second aqueous solution 155 accommodated in the second accommodating space 151, and an anode 158 at least partially submerged in the second aqueous solution; A power supply device 160 connecting the cathode 118 and anode 158; a connecting portion 190 including a connecting passage 191 that communicates the first accommodating space 111 and the second accommodating space 151, and an ion exchange membrane 192 provided in the connecting passage; And a calcium carbonate generating unit 120 connected to the first accommodating space 111 and the second accommodating space 151 to generate calcium carbonate (CaCO _{3 (S)} ).

The cathode portion 110 may include a first aqueous solution 115 accommodated in the first accommodation space 111, and a cathode 118 that is at least partially submerged in the first aqueous solution 115.

The first aqueous solution 115 is an aqueous electrolyte. Specifically, it may be an alkaline aqueous solution in which an alkali metal hydroxide (e.g., LiOH, NaOH, or KOH) is dissolved in water, and is preferably an alkaline aqueous solution in which carbon dioxide is easily dissolved. It may be an aqueous KOH solution.

According to one embodiment, the first aqueous solution 115 may be obtained by eluting CO ₂ from a strong basic solution of 1M KOH.

The cathode 118 is an electrode for forming a water electrolysis system and may be a reduction electrode that receives electrons (e ^- ) and generates hydrogen gas (H ₂ ).

Specifically, the cathode 118 may be a material that can cause a reduction reaction through electrons (e ^- ) generated when power is supplied to the power supply device.

According to one embodiment, the cathode 118 may be one or more selected from the group consisting of carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, and metal thin film.

The cathode 118 may further include a catalyst within the cathode to promote the reduction reaction. Specifically, it may include a hydrogen evolution reaction catalyst.

In one embodiment, the cathode 118 may include one or more selected from the group consisting of a platinum catalyst, a carbon-based catalyst, a carbon-metal composite catalyst, and a perovskite oxide catalyst, preferably , it may further include a platinum catalyst known to have the highest catalytic activity for the hydrogen generation reaction in an aqueous electrolyte.

The first inlet 112 may be located at the lower part of the first receiving space 111 so as to be located below the water surface of the first aqueous solution 115. The first outlet 113 may be located at the upper part of the first receiving space 111 so as to be above the water surface of the first aqueous solution 115. Carbon dioxide, which is used as a raw material during the discharge process, flows into the first receiving space 111 through the first inlet 112, and when necessary, the first aqueous solution 115 can also flow in. Gas generated during the water electrolysis process can be discharged to the outside through the first outlet 113. Although not shown, the inlet 112 and outlet 113 may be selectively opened and closed at appropriate times by a valve or the like during charging and discharging. The first connector 114 is located below the water surface of the first aqueous solution 115, and a connector 190 is connected to the first connector 114. A carbon dioxide elution reaction may occur in the cathode 110 during the water electrolysis process.

The anode 150 may include a second aqueous solution 155 accommodated in the second accommodating space 151, and an anode 158 at least partially submerged in the second aqueous solution 155, and preferably, the electronic It may be an oxidation electrode part where an oxidation reaction that generates (e ^- ) occurs.

The second aqueous solution 155 is an aqueous electrolyte. Specifically, it may be an alkaline aqueous solution in which an alkali metal hydroxide (e.g., LiOH, NaOH, or KOH) is dissolved in water, and is preferably oxidized through an oxygen generation reaction. It may be a high-concentration KOH aqueous solution that facilitates the reduction reaction.

According to one embodiment, the second aqueous solution 155 may be a 1M KOH or 6M KOH strongly basic solution.

The anode 158 may have one side in contact with the second electrolyte 155, but is preferably positioned so that at least part of the anode 158 is submerged in the second electrolyte 155.

The anode 158 is an oxidizing electrode that forms a water electrolysis system, and can generate electrons (e ^- ) through the oxidation reactions of oxygen evolution reaction (OER) and chlorine evolution reaction (CER), and preferably, generate oxygen. Reaction (Oxygen Evolution Reaction, OER) catalyst may be included.

According to one embodiment, the oxygen generation reaction catalyst included in the anode may be one or more selected from the group consisting of a metal oxide catalyst, a perovskite oxide catalyst, a metal sulfide catalyst, a metal carbide catalyst, and a carbon catalyst, wherein , the metal contained in the oxygen evolution reaction catalyst is selected from the group consisting of Li, Co, Ni, Zn, Fe, Ti, Na, Mn, Cu, Ga, Sn, Cr, W, Ru, Ir, Pt, and Au. There may be at least one type.

The anode unit 150 may further include a third inlet 127, a second outlet 153, and a second connector 154 that communicate with the second accommodation space 151.

The third inlet 127 may be located at the lower part of the second receiving space 151 so as to be located below the water surface of the second aqueous solution 155. The second outlet 153 may be located at the upper part of the second receiving space 151 so as to be above the water surface of the second aqueous solution 155.

The remaining liquid remaining after generating calcium carbonate in the calcium carbonate (CaCO _{3 (S)} ) generating unit 120 may be injected into the second receiving space 151 through the third inlet 127. Oxygen (O ₂ ) and chlorine (Cl ₂ ), which are gases generated when power is supplied to the power supply device, may be discharged to the outside through the second outlet 153. Although not shown, the third inlet 127 and the second outlet 153 may be selectively opened and closed at appropriate times by a valve or the like when the power supply device is supplied with power.

The anode part 150 may be formed with a second connector 154 communicating 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 may be connected to the second connector 154.

The connection part 190 is a connection passage 191 connecting the first accommodation space 111 of the cathode unit 110 and the second accommodation space 151 of the anode unit 150, and the interior of the connection passage 191. It may be provided with an ion exchange membrane (membrane) 192 installed in the.

Specifically, the connection passage 191 extends between the first connector 114 formed in the cathode portion 110 and the second connector 154 formed in the anode portion 150 to connect the first connector 114 of the cathode portion 110. The receiving space 111 and the second receiving space 151 of the anode unit 150 may be connected. An ion exchange membrane 192 may be provided inside the first connection passage 191.

The ion exchange membrane 192 may be installed to block the interior of the connection passage 191. The ion exchange membrane 192 only allows the movement of ions between the cathode portion 110 and the anode portion 150, thereby resolving ion imbalance occurring during the water electrolysis process.

Specifically, alkali metal ions, specifically potassium ions (K ⁺ ), contained in the second electrolyte solution 155 can move to the first electrolyte solution 115 by the ion exchange membrane 192.

According to one embodiment, Nafion, a fluororesin-based cation exchange membrane developed by DuPont in the United States, may be used as the ion exchange membrane 192.

The calcium carbonate generating unit 120 includes a reactor 121 that generates calcium carbonate (CaCO _3(S) ); A first inlet 123 that connects the first accommodation space 111 and the reactor 121 and injects bicarbonate ions (HCO ₃ ^- ) in the first accommodation space 111 into the reactor 121; A second inlet 125 connected to the reactor 121 and introducing calcium ions (Ca ²⁺ ) into the reactor 121; and a third inlet 127 that connects the second accommodation space 151 and the reactor 121 and injects the remaining liquid after the calcium carbonate (CaCO _3(S) ) production reaction into the second accommodation space 151; may include.

The first inlet 123 connects the first accommodating space 111 and the reactor 121, and bicarbonate ions (HCO ₃ ^- ), which are the product after reaction in the first accommodating space 111, are converted into calcium carbonate (CaCO _3(S) ) can be introduced into the reactor 121 of the production unit 120.

According to one embodiment, KHCO _3(aq), which is a product after reaction in the first receiving space 111, may be introduced into the reactor 121.

The second inlet 125 is connected to the reactor 121, and reacts with bicarbonate ions (HCO ₃ ^- ) introduced into the reactor 121 through the first inlet 123 to produce calcium carbonate (CaCO _{3 (S).} ) Calcium ions (Ca ²⁺ ) that can generate can be introduced.

According to one embodiment, CaCl _2(aq) may be added to the reactor 121.

The reactor 121 reacts with bicarbonate ions (HCO ₃ ^- ) introduced from the first inlet 123 and calcium ions (Ca ²⁺ ) introduced from the second inlet 125 to produce calcium carbonate (CaCO _{3 (S)} ) is produced, and residues may remain after the production reaction.

According to one embodiment, the residue may be KCl _(aq) .

The third inlet 127 is connected to the second receiving space 151 and the reactor 121, and the remaining liquid after the production reaction in the reactor 121 is injected into the second receiving space 151 to form the anode 158. It is possible to provide a solution that progresses the oxygen evolution reaction (OER) and the chlorine evolution reaction (CER).

Figure 8 is a schematic diagram showing the water electrolysis process of a water electrolysis system according to another embodiment. Referring to FIG. 8, the secondary battery 100a includes a cathode portion 110, an anode portion 150, a connection portion 190 connecting the cathode portion 110 and the anode portion 150, and a cathode portion 110. 1 Calcium carbonate generating unit 120, carbon dioxide processing unit 130, carbon dioxide circulation supply unit 135, and cathode unit 110 connecting the accommodation space 111 and the second accommodation space 151 of the anode unit 150. It may include a first connection pipe 140 that communicates with the carbon dioxide treatment unit 130.

Among the contents related to the cathode unit 110, anode unit 150, connection unit 190, and calcium carbonate generating unit 120, contents that overlap with the description of the water electrolysis system shown in FIG. 7 can be omitted. there is.

The carbon dioxide processing unit 130 may be in communication with the first accommodation space 111.

The third aqueous solution 135 accommodated in the third accommodating space 131 in the carbon dioxide treatment unit 130 may be the same aqueous solution as the first aqueous solution 115 of the cathode unit 110.

The carbon dioxide treatment unit 130 includes a second inlet 132 through which carbon dioxide flows into the third accommodation space 131, a communication port (not shown) to which the connection pipe 140 is connected, and a third accommodation space 131. It may include a third outlet 133 located at the top.

The second inlet 132 may be located above the communication port (not shown) in the fourth receiving space 131 and below the water level of the third outlet 133 and the third aqueous solution 135. Carbon dioxide gas, which is used as a fuel in the water electrolysis process, can flow into the third receiving space 131 through the second inlet 132, and a third aqueous solution 135 can also be supplied through the second inlet 132 as needed. can be supplied.

The third outlet 133 is located above the water level of the second inlet 132 and the third aqueous solution 135 in the third accommodation space 131. Carbon dioxide gas that is not dissolved in the fourth aqueous solution 135 in the fourth accommodating space 131 through the third outlet 133 and thus is not ionized floats to the top due to the difference in specific gravity and is finally discharged to the outside. Carbon dioxide gas discharged through the third outlet 133 may be supplied to the second inlet 132 through the carbon dioxide circulation supply unit 135.

This has the advantage of increasing the purity of hydrogen (H ₂ ) gas discharged from the first outlet 113. In other words, the existing method did not include a separate carbon dioxide treatment unit, so there was a disadvantage in that unionized carbon dioxide gas and hydrogen gas generated from the secondary battery were mixed and discharged, lowering the purity. However, the water electrolysis system according to another embodiment has a carbon dioxide treatment unit 130, so that among the carbon dioxide introduced into the third accommodation space 131, the carbon dioxide gas that is not dissolved in the third aqueous solution and thus not ionized is disposed of in the cathode unit 110. Unable to move to the first receiving space 111, the non-ionized carbon dioxide gas is discharged separately through the third outlet 133, making a difference from the first outlet 113 through which hydrogen gas generated in the water electrolysis system is discharged. There is an advantage in obtaining high purity hydrogen gas.

Meanwhile, the second inlet 132 and the first outlet 113 may be selectively opened and closed at appropriate times by a valve or the like during charging and discharging.

The communication port (not shown) is located below the second inlet 132 in the third receiving space 131, and a connection pipe 140 may be connected to the communication port (not shown). The third accommodation space 131 may be in communication with the first accommodation space 111 through the connection pipe 140 connected to the communication port (not shown).

The connection pipe 140 may connect the first inlet 112 of the first accommodation space 111 and the communication port (not shown) of the third accommodation space 131. The first accommodating space 111 and the third accommodating space 121 may be communicated through a connection passage (not shown) formed inside the connecting pipe 140.

The carbon dioxide circulation supply unit 135 may circulate the carbon dioxide gas discharged through the third outlet 133 to the second inlet 132 and re-supply it.

That is, among the carbon dioxide that flows into the fourth accommodation space 131 of the carbon dioxide processing unit 130 through the second inlet 132, the carbon dioxide gas that is not ionized because it is not dissolved in the fourth aqueous solution 135 is connected to the first electrode unit 110. ) fails to move to the first accommodation space 111 and rises, collects in the space above the water surface of the fourth aqueous solution 135 in the fourth accommodation space 131, and is then discharged through the third outlet 133 and the third outlet ( The carbon dioxide gas discharged through 133) is supplied to the fourth accommodation space 131 through the second inlet 132 by the carbon dioxide circulation supply unit 135 and is recycled.

Therefore, the secondary battery according to another embodiment has the advantage of increasing the energy efficiency of the battery because it can supply non-ionized carbon dioxide gas to the second inlet 132 through the carbon dioxide circulation supply unit 135.

The water electrolysis process of the water electrolysis system (100, 100a) is as follows. Figure 7 or Figure 8 shows the water electrolysis process of the water electrolysis system (100, 100a). Referring to this, carbon dioxide as a raw material for hydrogen production is injected into the first aqueous solution 115 through the first inlet 112, and a chemical elution reaction of carbon dioxide occurs in the cathode portion 110 as shown in the following [Reaction Formula 10].

[Scheme 10]

H ₂ O(l) + CO ₂ (g) → H ⁺ (aq) + HCO ₃ ^- (aq)

^{That is, the cathode unit 110 produces hydrogen cations (H +} ₎ _and bicarbonate ( HCO ₃ ^- ) can be produced.

Additionally, an electrical reaction occurs in the cathode portion 110 as shown in [Reaction Formula 11].

[Scheme 11]

2H ⁺ (aq) + 2e ^- → H ₂ (g)

That is, in the cathode portion 110, hydrogen positive ions (H+) receive electrons (e ^- ) and hydrogen (H ₂ ) gas is generated. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 113.

In summary, a complex hydrogen generation reaction occurs in the cathode portion 110 as shown in [Reaction Formula 12].

[Scheme 12]

2H ₂ O(l) + 2CO ₂ (g) + 2e ^- → H ₂ (g) + 2HCO ₃ ^- (aq)

The aqueous solution containing bicarbonate (HCO ₃ ^- ) generated from the complex hydrogen generation reaction may be introduced into the reactor 121 of the calcium carbonate (CaCO _{3 (S)} ) production unit through the first inlet 123 along with positive ions.

At this time, the cation contained in the aqueous solution containing bicarbonate may be one or more types selected from the group consisting of potassium cation (K ⁺ ), sodium cation (Na ⁺ ), lithium (Li ⁺ ), and magnesium (Mg ⁺ ).

According to one embodiment, an aqueous solution of KHCO _{3 (aq)} may be introduced into the reactor 121.

Bicarbonate (HCO ₃ ^- ) introduced into the reactor 121 is an aqueous solution containing calcium ions (Ca ²⁺ ) introduced into the reactor through the second inlet 125 and a calcium carbonate production reaction as shown in [Reaction Formula 13]. It comes true.

[Scheme 13]

2 KHCO _3(aq) + CaCl _2(aq) → 2 KCl _(aq) + CO _2(g) + CaCO _3(s) + H ₂ O _(l)

or

K ₂ CO _3(aq) + CaCl _2(aq) → 2 KCl _(aq) + CaCO _3(s)

At this time, the anion contained in the aqueous solution containing calcium ion (Ca ²⁺ ) is selected from the group consisting of chlorine anion (Cl ^- ), hydroxide ion (OH ^- ), fluorine (F ^- ), and bromine (Br ^- ). There may be more than one type.

According to one embodiment, an aqueous CaCl _{2 (aq)} solution may be introduced into the reactor 121.

After the calcium carbonate production reaction, the remaining liquid may be injected into the anode unit 150 through the third inlet 127.

At this time, it may include cations contained in an aqueous solution containing bicarbonate and anions contained in an aqueous solution containing calcium ions (Ca ²⁺ ).

According to one embodiment, it may be an aqueous KCl _(aq) solution.

And, in the anode unit 150, the remaining liquid after the calcium carbonate generation reaction injected from the third inlet 127 undergoes an oxidation reaction of oxygen evolution reaction (OER) as shown in [Reaction Formula 14].

[Scheme 14]

4 OH ^- _(aq) → O _2(g) + 2H ₂ O _(l) + 4 e ^-

Meanwhile, if the remaining liquid after the calcium carbonate generation reaction injected from the third inlet 127 contains chlorine ions (Cl-), the oxidation reaction of the chlorine generation reaction as shown in the following [Reaction Formula 15] also occurs.

[Scheme 15]

2 Cl ^- _(aq) → Cl _2(g) + 2 e ^-

In other words, the water electrolysis system according to one aspect has the advantage of being able to produce not only oxygen and chlorine, but also hydrogen and calcium carbonate with high purity.

Figure 9 is a schematic diagram showing the discharge process of a composite secondary battery using carbon dioxide according to an embodiment. Referring to FIG. 9, a first electrode portion including a first aqueous solution 115 accommodated in the first accommodation space 111 and a first electrode 118 at least partially submerged in the first aqueous solution 115 ( 110); a second electrode unit 150 including a second aqueous solution 155 accommodated in the second accommodating space 151, and a second electrode 158 at least partially submerged in the second aqueous solution; A first connection portion 190 including a connection passage 191 that communicates the first accommodation space 111 and the second accommodation space 151, and a cation exchange membrane 192 provided in the connection passage; A third electrode unit 170 including a third aqueous solution 175 accommodated in the third accommodating space 171, and a third electrode 178 at least partially submerged in the third aqueous solution 175; A second connection portion including a connection passage 191' that communicates the second accommodation space 151 and the third accommodation space 171, and an exchange membrane 192' provided in the connection passage 191' ( 190'); and a power supply device 160 connected to the second electrode 158 and the third electrode 178.

The first electrode unit 110 may include a first aqueous solution 115 accommodated in the first accommodation space 111, and a first electrode 118 at least partially submerged in the first aqueous solution 115. Preferably, it may be a reduction electrode unit capable of generating hydrogen gas.

The first aqueous solution 115 may be a neutral aqueous solution, an alkaline aqueous solution, seawater, tap water, or distilled water, and may preferably be an alkaline aqueous solution in which carbon dioxide is easily dissolved.

According to one embodiment, the first aqueous solution 115 may be a strongly basic solution of 1M NaOH, and may be used by further eluting CO ₂ during subsequent discharge.

One side of the first electrode 118 may be in contact with the first electrolyte, but preferably, it may be positioned so that at least a portion is submerged in the first electrolyte.

The first electrode 118 may be a reduction electrode capable of forming an electric circuit and generating hydrogen gas during discharge.

The first electrode 118 is made of materials that can cause a reduction reaction through electrons (e ^- ) generated from the second electrode, such as carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, and metal thin film. It may be one or more types selected from the group consisting of.

The first electrode 118 may further include a catalyst in the first electrode to promote a reduction reaction. Specifically, it may be a hydrogen evolution reaction catalyst, for example, one or more types selected from the group consisting of platinum catalysts, carbon-based catalysts, carbon-metal composite catalysts, and perovskite oxide catalysts. It may include, and preferably, may further include a platinum catalyst having excellent electrochemical activity for the hydrogen generation reaction.

The first electrode unit 110 may further include a first inlet 112, a first outlet 113, and a first connector 114 that communicate with the first accommodation space 111.

The first inlet 112 may be located at the lower part of the first receiving space 111 so as to be located below the water surface of the first aqueous solution 115. The first outlet 113 may be located at the upper part of the first receiving space 111 so as to be above the water surface of the first aqueous solution 115. Carbon dioxide, which is used as a raw material during the discharge process, flows into the first receiving space 111 through the first inlet 112, and when necessary, the first aqueous solution 115 can also flow in. Gas generated during charging and discharging can be discharged to the outside through the first outlet 113. Although not shown, the inlet 112 and outlet 113 may be selectively opened and closed at appropriate times by a valve or the like during charging and discharging. The first connector 114 is located below the water surface of the first aqueous solution 115, and a connector 190 is connected to the first connector 114. A carbon dioxide elution reaction may occur in the first electrode unit 110 during the discharge process.

The second electrode unit 150 may include a second aqueous solution 155 accommodated in the second receiving space 151, and a second electrode 158 at least partially submerged in the second aqueous solution 155. Preferably, it may be an oxidation electrode part where an oxidation reaction that generates electrons (e ^- ) occurs.

The second aqueous solution 155 can promote the electrochemical reaction of the metal electrode unit 158, and preferably, a high concentration alkaline aqueous solution with dominant conductivity of cation Na ⁺ or K ⁺ can be used.

According to one embodiment, the second aqueous solution 155 may be a 1M NaOH or 6M NaOH strongly basic solution.

The second electrode 158 may have one side in contact with the second electrolyte 155, but is preferably positioned so that at least part of the second electrode 158 is submerged in the second electrolyte 155.

The second electrode 158 is an oxide electrode made of a metal material that forms an electric circuit, and is not particularly limited as long as it can generate electrons (e ^- ) through an oxidation reaction. For example, zinc (Zn), aluminum (Al) ), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), lithium (Li), sodium (Na), magnesium (Mg), nickel (Ni), and copper (Cu). ) may be an alloy containing one type of metal or two or more types selected from the group consisting of ), and preferably includes zinc (Zn) or aluminum (Al), which has high electrochemical reaction and high voltage in an alkaline environment. .

A second connector 154 communicating with the second receiving space 151 is formed in the second electrode portion 150. The second connector 154 is located below the water surface of the second aqueous solution 155, and the connector 190 may be connected to the second connector 154.

The first connection portion 190 includes a first connection passage 191 connecting the first accommodating space 111 of the first electrode portion 110 and the second accommodating space 151 of the second electrode portion 150, and A cation exchange membrane 192 installed inside the first connection passage 191 may be provided.

Preferably, the first connection passage 191 extends between the first connector 114 formed on the first electrode portion 110 and the second connector 154 formed on the second electrode portion 150. The first accommodating space 111 of the first electrode unit 110 and the second accommodating space 151 of the second electrode unit 150 may be connected. A cation exchange membrane 192 may be provided inside the first connection passage 191.

The cation exchange membrane 192 may be installed to block the interior of the first connection passage 191. The cation exchange membrane 192 allows only the movement of ions between the first electrode portion 110 and the first electrode portion 150 to resolve ion imbalance occurring during the discharge process, preferably, Cations contained in the second aqueous solution 155 may move to the first aqueous solution 115.

According to one embodiment, as a membrane capable of moving cations to the cation exchange membrane 192, Nafion-212, 217, a fluororesin-based cation exchange membrane developed by DuPont in the United States, etc. You can use it.

The third electrode unit 170 may include a third aqueous solution 175 accommodated in the third accommodation space 171, and a third electrode 178 that is at least partially submerged in the third aqueous solution 175. . Preferably, at the same time that a spontaneous discharge reaction occurs in the first electrode 118 and the second electrode 158, the third electrode 178 and the second electrode 158 are connected to the power supply and are connected to the power supply. When power is supplied, oxidation reactions of oxygen evolution reaction (OER) and chlorine evolution reaction (CER) may occur in the third electrode 178.

The third aqueous solution 175 may be a neutral or slightly alkaline aqueous solution or an aqueous electrolyte containing Cl ^- ions.

According to one embodiment, the third aqueous solution 175 may be a potassium chloride (KCl) solution.

The third electrode 178 may have one side in contact with the third electrolyte 175, but is preferably positioned so that at least part of the third electrode 178 is submerged in the third electrolyte 175.

The third electrode 178 is an oxidizing electrode made of metal that forms an electric circuit with the second electrode 158, and generates electrons (e ^- ) through the oxidation reactions of the oxygen evolution reaction (OER) and the chlorine evolution reaction (CER). There is no particular limitation as long as it can be generated, and for example, one metal selected from the group of metal oxide catalysts, perovskite oxide catalysts, metal sulfide catalysts, metal carbide catalysts, and carbon catalysts, or an alloy containing two or more kinds It may include Pt, Ir, and IrOx, which are noble metal-based catalysts.

The third electrode unit 170 may further include a third inlet 127, a second outlet 173, and a third connector 174 that communicate with the third accommodation space 171.

The third inlet 127 may be located below the third accommodating space 171 so as to be below the water surface of the third aqueous solution 175. The second outlet 173 may be located at the upper part of the third accommodation space 171 so as to be above the water surface of the third aqueous solution 175. The remaining liquid remaining after generating calcium carbonate in the calcium carbonate (CaCO _{3 (S)} ) generating unit 120 may be injected into the third receiving space 171 through the third inlet 127. Oxygen (O ₂ ) and chlorine (Cl ₂ ), which are gases generated when power is supplied to the power supply device, may be discharged to the outside through the third outlet 173. Although not shown, the third inlet 127 and the second outlet 173 may be selectively opened and closed at appropriate times by a valve or the like when the power supply device is supplied with power. A third connector 174 communicating with the second receiving space 151 is formed in the third electrode portion 170. The third connector 174 is located below the water surface of the third aqueous solution 175, and the second connector 190' may be connected to the third connector 174.

The second connection part 190' is a second connection passage 191' connecting the second accommodation space 151 of the second electrode unit 150 and the third accommodation space 171 of the third electrode unit 170. , and an exchange membrane 192' installed inside the second connection passage 191'.

Preferably, the second connection passage 191' extends between the second connector 154 formed in the second electrode portion 150 and the third connector 174 formed in the third electrode portion 170. The second accommodating space 151 of the second electrode unit 150 and the third accommodating space 171 of the third electrode unit 170 may be connected. A cation exchange membrane 192' may be provided inside the second connection passage 191'.

The exchange membrane 192' may be installed to block the interior of the second connection passage 191'. The exchange membrane 192' allows only the movement of ions between the first electrode portion 110 and the first electrode portion 150, thereby resolving ion imbalance occurring during the discharge process. Preferably, Cations contained in the third aqueous solution 175 may move to the second aqueous solution 155.

According to one embodiment, the membrane capable of moving positive ions (K+, Na+, etc.) to the exchange membrane 192 is Nafion (Nafion 212, 217), a fluororesin-based cation exchange membrane developed by DuPont in the United States. etc.) can be used.

The composite secondary battery 100 includes a reactor 121 that generates calcium carbonate (CaCO _{3 (S)} ); A first inlet 123 that connects the first accommodation space 111 and the reactor 121 and injects bicarbonate ions (HCO ₃ ^- ) in the first accommodation space 111 into the reactor 121; A second inlet 125 connected to the reactor 121 and introducing calcium ions (Ca ²⁺ ) into the reactor 121; and a third inlet 127 that connects the third accommodation space 171 and the reactor 121 and injects the remaining liquid after the calcium carbonate (CaCO _3(S) ) production reaction into the third accommodation space 171; It may include a calcium carbonate (CaCO _{3 (S)} ) generating unit 120 containing.

The first inlet 123 connects the first accommodating space 111 and the reactor 121, and bicarbonate ions (HCO ₃ ^- ), which are the product after reaction in the first accommodating space 111, are converted into calcium carbonate (CaCO _3(S) ) can be introduced into the reactor 121 of the production unit 120, and preferably, after reaction in the first receiving space 111, the product KHCO _3(aq) is introduced into the reactor 121. It can be.

The second inlet 125 is connected to the reactor 121, and reacts with bicarbonate ions (HCO ₃ ^- ) introduced into the reactor 121 through the first inlet 123 to produce calcium carbonate (CaCO _{3 (S).} ) Calcium ions (Ca ²⁺ ) capable of producing ) can be added, preferably CaCl _{2 (aq)} .

The reactor 121 reacts with bicarbonate ions (HCO ₃ ^- ) introduced from the first inlet 123 and calcium ions (Ca ²⁺ ) introduced from the second inlet 125 to produce calcium carbonate (CaCO _{3 (S)} ) is produced, and a residue may remain after the production reaction. Preferably, the residue may be KCl _(aq) .

The third inlet 127 is connected to the third receiving space 171 and the reactor 121, and injects the remaining liquid after the production reaction in the reactor 121 into the third receiving space 171 to form a third electrode 178. ), it is possible to provide a solution that progresses the oxygen generation reaction (OER) and the chlorine generation reaction (CER).

Figure 10 is a schematic diagram showing the discharge process of a composite secondary battery using carbon dioxide according to another embodiment. Referring to FIG. 10, the secondary battery 100a includes a first electrode portion 110, a second electrode portion 150, and a first connection portion connecting the first electrode portion 110 and the second electrode portion 150. 190), a third electrode unit 170, a second connection unit 190' connecting the second electrode unit 150 and the third electrode unit 170, and a second connection unit 190' connecting the first electrode unit 110 and the third electrode unit. a calcium carbonate generating unit 120, a carbon dioxide processing unit 130, a carbon dioxide circulation supply unit 135, a first connection pipe 140 communicating between the first electrode unit 110 and the carbon dioxide processing unit 130, and a residual liquid circulation. It may include a supply unit 160.

Related to the first electrode unit 110, the second electrode unit 150, the first connection unit 190, the third electrode unit 170, the second connection unit 190', and the calcium carbonate generating unit 120. Content that overlaps with the content described in the embodiment shown in FIG. 1 may be omitted.

The carbon dioxide treatment unit 130 is in communication with the first accommodation space 111, and the fourth aqueous solution 135 accommodated in the fourth accommodation space 131 is the first aqueous solution 115 of the first electrode unit 110. It may be the same aqueous solution as.

The carbon dioxide processing unit 130 includes a second inlet 132 through which carbon dioxide flows into the fourth accommodation space 131, a communication port 133 to which the connection pipe 140 is connected, and an upper portion of the fourth accommodation space 131. It may include a third outlet 134 located at.

The second inlet 132 may be located above the communication port 133 in the fourth receiving space 131, and may be located below the third outlet 134 and the water surface of the first aqueous solution 115. Carbon dioxide gas used as fuel during the discharge process can flow into the fourth receiving space 131 through the second inlet 132, and a fourth aqueous solution 135 is also supplied through the second inlet 132 as needed. It can be.

The third outlet 134 is located above the water level of the second inlet 132 and the first aqueous solution 115 in the fourth accommodation space 131. Carbon dioxide gas that is not dissolved in the fourth aqueous solution 135 in the fourth accommodating space 131 through the third outlet 134 and thus is not ionized floats to the top due to the difference in specific gravity and is finally discharged to the outside. Carbon dioxide gas discharged through the third outlet 134 may be supplied to the second inlet 132 through the carbon dioxide circulation supply unit 135.

This has the advantage of increasing the purity of hydrogen (H ₂ ) gas discharged from the first outlet 113. In other words, the existing method did not include a separate carbon dioxide treatment unit, so there was a disadvantage in that unionized carbon dioxide gas and hydrogen gas generated from the secondary battery were mixed and discharged, lowering the purity. However, the secondary battery according to another embodiment has a carbon dioxide treatment unit 130, so that among the carbon dioxide flowing into the third accommodation space 131, the carbon dioxide gas that is not ionized because it is not dissolved in the fourth aqueous solution is stored in the first electrode unit 110. ), the non-ionized carbon dioxide gas is separately discharged through the second outlet 134, thereby making the difference from the first outlet 113 through which hydrogen gas generated from the secondary battery is discharged. There is an advantage in being able to obtain high purity hydrogen gas.

The communication port 133 is located below the second inlet 132 in the fourth accommodation space 131, and a connection pipe 140 may be connected to the communication port 133. The fourth accommodating space 131 may be communicated with the first accommodating space 111 through the communication port 133.

The connection pipe 140 may connect the first inlet 112 of the first accommodation space 111 and the communication port 133 of the fourth accommodation space 131. The first accommodating space 111 and the fourth accommodating space 121 may be communicated through the connecting passage 141 formed inside the connecting pipe 140.

The carbon dioxide circulation supply unit 135 may circulate the carbon dioxide gas discharged through the third outlet 134 to the second inlet 132 and re-supply it.

That is, among the carbon dioxide that flows into the fourth accommodation space 131 of the carbon dioxide processing unit 130 through the second inlet 132, the carbon dioxide gas that is not ionized because it is not dissolved in the fourth aqueous solution 135 is connected to the first electrode unit 110. ) fails to move to the first accommodation space 111 and rises, collects in the space above the water surface of the fourth aqueous solution 135 in the fourth accommodation space 131, and is then discharged through the third outlet 134 and the third outlet ( The carbon dioxide gas discharged through 134) is supplied to the fourth accommodation space 131 through the second inlet 132 by the carbon dioxide circulation supply unit 135 and is recycled.

In addition, as the secondary battery according to another embodiment further includes a carbon dioxide circulation supply unit 135, the third electrode unit 170 receives the remaining liquid after the reaction as a fourth compartment when power is supplied from the power supply device 160. It further includes a residual liquid circulation supply unit 180 that re-supplies the fourth aqueous solution 135 in the space 131.

Therefore, the secondary battery according to another embodiment has the advantage of eliminating the need for continuous supply of positive ions, for example, additional supply of K+ or Na+ for carbon dioxide capture, as it further includes a residual liquid circulation supply unit 180.

The discharging process of the

secondary batteries

100 and 100a is as follows. Figure 9 or Figure 10 shows the discharging process of the

secondary batteries

100 and 100a. Referring to this, carbon dioxide is injected as a raw material for hydrogen production into the first aqueous solution 115 through the first inlet 112, and a chemical elution reaction of carbon dioxide is performed in the first electrode unit 110 as shown in [Reaction Formula 16]. It comes true.

[Scheme 16]

H ₂ O(l) + CO ₂ (g) → H ⁺ (aq) + HCO ₃ ^- (aq)

That is, the first electrode unit 110 converts carbon dioxide (CO ₂ ) supplied to the first electrode unit ₁₁₀ into hydrogen cations (H ⁺ ) and bicarbonate (HCO ₃ ^- ) can be produced.

Additionally, an electrical reaction occurs in the first electrode unit 110 as shown in [Reaction Formula 17].

[Scheme 17]

2H ⁺ (aq) + 2e ^- →H ₂ (g)

That is, in the first electrode unit 110, hydrogen positive ions (H+) receive electrons (e ^- ) and hydrogen (H ₂ ) gas is generated. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 113.

In addition, a complex hydrogen generation reaction occurs in the first electrode unit 110 as shown in [Reaction Formula 18].

[Scheme 18]

2H ₂ O(l) + 2CO ₂ (g) + 2e ^- → H ₂ (g) + 2HCO ₃ ^- (aq)

Bicarbonate (HCO ₃ ^- ) introduced into the reactor 121 is combined with an aqueous solution containing calcium ions (Ca ²⁺ ) introduced into the reactor through the second inlet 125 and a calcium carbonate production reaction as shown in [Reaction Formula 19]. It comes true.

[Scheme 19]

or

K ₂ CO _3(aq) + CaCl _2(aq) → 2 KCl _(aq) + CaCO _3(s)

After the calcium carbonate production reaction, the remaining liquid may be injected into the third electrode unit 170 through the third inlet 127.

According to one embodiment, it may be an aqueous KCl _(aq) solution.

And, when the second electrode 158 is zinc (Zn), an oxidation reaction occurs in the second electrode unit 150 as shown in [Reaction Formula 20].

[Scheme 20]

Zn + 4OH ^- → Zn(OH) ₄ ^2- + 2e ^- (E ⁰ = -1.25 V)

Zn(OH) ₄ ^2- → ZnO + H ₂ O + 2OH ^-

Ultimately, when the second electrode 158 is zinc (Zn), the overall reaction equation that occurs during the discharge process is as follows [Reaction Formula 21].

[Scheme 21]

Zn + 2CO ₂ + 2H ₂ O + 2OH ^- → ZnO + 2HCO ₃ ^- (aq) + H ₂ (g) (E ⁰ = 1.25 V)

If the second electrode 158 in the second electrode unit 150 is aluminum (Al), an oxidation reaction occurs as shown in [Reaction Formula 22].

[Scheme 22]

Al + 3OH ^- → Al(OH) ₃ + 3e ^- (E ⁰ = -2.31 V)

Ultimately, when the second electrode 158 is made of aluminum (Al), the overall reaction equation that occurs during the discharge process is as follows [Equation 23].

[Scheme 23]

2Al + 6CO ₂ + 6H ₂ O + 6OH ^- → 2Al(OH) ₃ + 6HCO ₃ ^- _(aq) + 3H ₂ (g) (E ⁰ = 2.31 V)

As a result, as can be seen through [Reaction Formula 21] and [Reaction Formula 23], hydrogen ions generated by carbon dioxide eluted from the first aqueous solution 115 during discharge receive electrons from the first electrode 118 and form hydrogen. It is reduced to gas and discharged through the first outlet 113, and the second electrode 158 changes to the form of an oxide. During discharge, potassium ions (K ⁺ ) contained in the second aqueous solution 155 of the second electrode unit 150 pass through the cation exchange membrane 192 and move to the first aqueous solution 115 of the first electrode unit 110. By doing so, it is possible to prevent changes in KOH concentration due to carbon dioxide supply.

Meanwhile, when power is applied to the power supply device 160 at the same time as the discharge reaction of the secondary battery occurs, the following reaction may proceed.

Specifically, in the third electrode unit 170, the remaining liquid after the calcium carbonate generation reaction injected from the third inlet 127 undergoes an oxygen generation reaction ( OER) oxidation reaction takes place.

[Scheme 24]

4 OH ^- _(aq) → O _2(g) + 2H ₂ O _(l) + 4 e ^-

Meanwhile, if the remaining liquid after the calcium carbonate generation reaction injected from the third inlet 127 contains chlorine ions (Cl-), the oxidation reaction of the chlorine generation reaction as shown in the following [Reaction Formula 25] also occurs.

[Scheme 25]

2 Cl ^- _(aq) → Cl _2(g) + 2 e ^-

At this time, while the previously mentioned reaction is carried out through discharge in the second electrode unit 150, the reduction reaction of the metal production reaction can occur simultaneously depending on the application of power to the power supply device 160. In particular, when the second electrode 158 of the second electrode unit 150 is zinc, a reaction occurs as shown in [Reaction Formula 26], and the second electrode 158 of the second electrode unit 150 is aluminum. In this case, the reaction proceeds as shown in [Reaction Formula 27].

[Scheme 26]

Zn(OH) ₄ ^2- + 2e ^- → Zn + 4OH ^-

[Scheme 27]

Al(OH) ₃ + 3e ^- → Al + 3OH ^-

That is, the composite secondary battery according to one embodiment is capable of producing high-purity hydrogen gas and calcium carbonate through a spontaneous discharge reaction of the secondary battery, but is consumed by discharge according to the application of power to the power supply device of the third electrode and the second electrode. Since the metal of the second electrode can be regenerated, there is an advantage in that calcium carbonate can be produced economically and efficiently by applying power to the power supply device without replacing the metal of the second electrode.

Claims

A cathode portion including a first aqueous solution containing potassium hydroxide accommodated in a first accommodating space, and a cathode at least partially submerged in the first aqueous solution;

an anode portion including a second aqueous solution containing chlorine ions (Cl - ) accommodated in the second accommodating space, and a metal anode at least partially immersed in the second aqueous solution;

a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; and

It includes a carbon dioxide treatment unit that communicates with the first accommodating space and has a first aqueous solution accommodated in the third accommodating space,

During discharging, the anode unit oxidizes chlorine ions (Cl - ) to generate chlorine gas (Cl 2 ) and electrons (e - ), and carbon dioxide gas flows into the first aqueous solution in the third receiving space, thereby generating the first aqueous solution. Hydrogen ions (H + ) and bicarbonate ions (HCO 3 - ) are generated by the reaction of the aqueous solution and the carbon dioxide gas, and the cathode unit combines the hydrogen ions (H + ) with the electrons of the cathode to produce hydrogen gas (H 2 ) A secondary battery characterized in that it generates.
According to paragraph 1,

The carbon dioxide processing unit

A secondary battery wherein un-ionized carbon dioxide gas among carbon dioxide gas flowing into the first aqueous solution of the third accommodation space is separated from the first aqueous solution to prevent it from being supplied to the cathode portion.
According to paragraph 2,

The carbon dioxide processing unit,

A secondary battery that separates the un-ionized carbon dioxide gas using a difference in specific gravity from the first aqueous solution.
According to paragraph 2,

The carbon dioxide processing unit

A secondary battery that collects the un-ionized carbon dioxide gas from an upper portion of the water surface of the first aqueous solution in the third accommodation space.
According to paragraph 2,

The carbon dioxide processing unit

an inlet located below the water surface of the first aqueous solution in the third accommodation space and through which carbon dioxide gas flows; and

A secondary battery further comprising a communication port located below the inlet and formed to communicate with the first accommodating space in the third accommodating space.
According to paragraph 1,

The cathode part

The secondary battery further includes a first outlet located above the water surface of the first aqueous solution accommodated in the first accommodation space and discharging hydrogen gas generated during discharge.
According to paragraph 2,

The carbon dioxide processing unit

The secondary battery further includes a second outlet located above the water surface of the first aqueous solution in the third accommodation space, through which the non-ionized carbon dioxide gas is discharged during discharge.
According to paragraph 2,

The carbon dioxide processing unit

A secondary battery further comprising a carbon dioxide circulation supply unit that supplies the non-ionized carbon dioxide gas to the first aqueous solution in the third accommodation space.
According to paragraph 1,

The second aqueous solution is

A secondary battery comprising one or more cations selected from the group consisting of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), aluminum (Al), and lithium (Li).
According to paragraph 1,

The second aqueous solution is

A secondary battery containing seawater.
According to paragraph 1,

When discharging, the cathode part

A secondary battery comprising at least one carbonate selected from the group consisting of sodium bicarbonate (NaHCO 3 ), potassium bicarbonate (KHCO 3 ), calcium carbonate (CaCO 3 ), and magnesium carbonate (MgCO 3 ).
A secondary battery according to claim 1, which generates hydrogen using carbon dioxide as a raw material during the discharge process; and

A combined power generation system comprising a fuel cell supplied with hydrogen generated from the secondary battery as fuel.
a cathode portion including a first aqueous solution contained in a first accommodating space, and a cathode at least partially submerged in the first aqueous solution;

An anode comprising a second aqueous solution accommodated in a second accommodating space and containing a calcium salt containing calcium ions (Ca 2+ ) and chlorine ions (Cl - ), and a metal anode at least partially immersed in the second aqueous solution. wealth;

a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and a cation exchange membrane located in the connecting passage; and

It includes a carbon dioxide treatment unit having a first aqueous solution accommodated in a third accommodating space in communication with the first accommodating space, and injecting a carbon dioxide-containing gas into the third accommodating space,

During discharging, the anode unit oxidizes chlorine ions (Cl - ) to generate chlorine gas (Cl 2 ) and electrons (e - ), and carbon dioxide gas flows into the first aqueous solution in the third accommodation space, thereby generating the first aqueous solution. Hydrogen ions (H + ) and bicarbonate ions (HCO 3 - ) are generated by the reaction of the aqueous solution and the carbon dioxide gas, and the cathode unit combines the water (H 2 O) with the electrons generated at the anode to produce hydroxide ions ( A secondary battery characterized in that OH - ) and hydrogen gas (H 2 ) are generated.
According to clause 13,

The carbon dioxide processing unit

A secondary battery wherein un-ionized carbon dioxide gas among carbon dioxide gas flowing into the first aqueous solution of the third accommodation space is separated from the first aqueous solution to prevent it from being supplied to the cathode portion.
According to clause 14,

The carbon dioxide processing unit,

A secondary battery that separates the un-ionized carbon dioxide gas using a difference in specific gravity from the first aqueous solution.
According to clause 14,

The carbon dioxide processing unit

A secondary battery that collects the un-ionized carbon dioxide gas from an upper portion of the water surface of the first aqueous solution in the third accommodation space.
According to clause 14,

The carbon dioxide processing unit

an inlet located below the water surface of the first aqueous solution in the third accommodation space and through which carbon dioxide gas flows; and

A secondary battery further comprising a communication port located below the inlet and formed to communicate with the first accommodating space in the third accommodating space.
According to clause 13,

The cathode part

The secondary battery further includes a first outlet located above the water surface of the first aqueous solution accommodated in the first accommodation space and discharging hydrogen gas generated during discharge.
According to clause 14,

The carbon dioxide processing unit

The secondary battery further includes a second outlet located above the water surface of the first aqueous solution in the third accommodation space, through which the non-ionized carbon dioxide gas is discharged during discharge.
According to clause 14,

The carbon dioxide processing unit

A secondary battery further comprising a carbon dioxide circulation supply unit that supplies the non-ionized carbon dioxide gas to the first aqueous solution in the third accommodation space.
According to clause 13,

The first aqueous solution is

A secondary battery comprising at least one compound selected from the group consisting of KOH and KHCO 3 .
According to clause 13,

When discharging, the cathode part

A secondary battery in which calcium ions (Ca 2+ ) moved through a cation exchange membrane react with hydroxide ions (OH - ) and bicarbonate (HCO 3 - ) to produce calcium carbonate (CaCO 3 ).
An elution reactor for eluting calcium ions from a calcium-containing material using an eluting agent to produce a second aqueous solution containing calcium ions (Ca 2+ ) and chlorine ions (Cl - ); and

A calcium carbonate manufacturing facility comprising a secondary battery to which a carbon dioxide-containing gas and the second aqueous solution are supplied and which produces calcium carbonate (CaCO 3 ) through a reaction.
According to clause 23,

When discharging the secondary battery,

The eluting agent remains in the first receiving space,

The calcium carbonate (CaCO 3 ) is a calcium carbonate manufacturing facility in which the calcium carbonate (CaCO 3 ) is produced in the second receiving space.
According to clause 23,

The eluent is

Equipment for manufacturing calcium carbonate, which is an ammonium salt.
According to clause 23,

The carbon dioxide-containing gas is

Steel exhaust gas, high purity carbon dioxide, FOG (FINEX off gas), FINEX tail gas (FTG), blast furnace gas (BFG), converter gas, coal power plant exhaust gas, gas power plant exhaust gas, incinerator A calcium carbonate manufacturing facility that is at least one selected from the group consisting of flue gas, glass melting flue gas, heat facility flue gas, petrochemical process flue gas, petrochemical process process gas, pre-/post-combustion flue gas, and gasifier flue gas.
According to clause 23,

The calcium-containing material is one or more calcium carbonates selected from the group consisting of waste cement, waste concrete, coal ash, fly ash, iron slag, quicklime (CaO), calcium chloride (CaCl 2 ), wollastonite, limestone, olivine, serpentine, asbestos, and deinked ash. Manufacturing facilities.
An elution step of eluting calcium ions from a calcium-containing material using an eluting agent to produce a second aqueous solution; and

A method for producing calcium carbonate comprising a step of producing calcium carbonate (CaCO 3 ) by reacting carbon dioxide-containing gas and the second aqueous solution with sodium hydroxide (NaOH) generated during discharging of the secondary battery according to claim 1.
a cathode portion including a first aqueous solution contained in a first accommodating space, and a cathode (anode) at least partially submerged in the first aqueous solution;

an anode portion including a second aqueous solution contained in a second accommodating space and a metal anode at least partially submerged in the second aqueous solution;

A power supply device connecting the cathode and anode;

a connecting portion including a connecting passage that communicates the first accommodating space and the second accommodating space, and an ion exchange membrane located in the connecting passage; and

It includes a calcium carbonate generating unit connected to the first accommodating space and the third accommodating space to generate calcium carbonate (CaCO 3 (S) ),

When power is supplied to the power supply device, carbon dioxide gas flows into the first electrolyte from the cathode, and hydrogen ions (H + ) and bicarbonate ions (HCO 3 - ) are generated by the reaction of the first electrolyte and the carbon dioxide gas. , A water electrolysis system characterized in that hydrogen gas (H 2 ) is generated by combining the hydrogen ions (H + ) and electrons (e - ) supplied by power supply.
According to clause 29,

The calcium carbonate producing unit

A reactor for producing calcium carbonate (CaCO 3(S) );

A first inlet connecting the first accommodation space and the reactor and introducing bicarbonate ions (HCO 3 - ) from the first accommodation space into the reactor;

A second inlet connected to the reactor and introducing calcium ions (Ca 2+ ) into the reactor; and

A third inlet connects the third accommodating space and the reactor and injects the remaining liquid after the calcium carbonate (CaCO 3 (S) ) production reaction into the third accommodating space,

Water electrolysis system.
According to clause 29,

A water electrolysis system wherein the anode includes an oxygen evolution reaction catalyst.
According to clause 31,

The oxygen generation reaction catalyst is

A water electrolysis system comprising at least one selected from the group consisting of metal oxide catalysts, perovskite oxide catalysts, metal sulfide catalysts, metal carbide catalysts, and carbon catalysts.
According to clause 32,

The metal contained in the oxygen generation reaction catalyst is

A water electrolysis system comprising at least one selected from the group consisting of Li, Co, Ni, Zn, Fe, Ti, Na, Mn, Cu, Ga, Sn, Cr, W, Ru, Ir, Pt, and Au.
According to clause 29,

The water electrolysis system wherein the cathode includes carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, and metal thin film.
According to clause 34,

The water electrolysis system wherein the cathode further includes a hydrogen evolution reaction catalyst.
According to clause 29,

The carbon dioxide processing unit

A water electrolysis system further comprising a carbon dioxide treatment unit that communicates with the first accommodation space and includes a third aqueous solution accommodated in the third accommodation space.
According to clause 36,

The carbon dioxide processing unit

A water electrolysis system that separates un-ionized carbon dioxide gas from the carbon dioxide gas flowing into the third receiving space from the third aqueous solution and prevents it from being supplied to the anode part.
According to clause 36,

The carbon dioxide processing unit

A water electrolysis system that separates the non-ionized carbon dioxide gas using the difference in specific gravity from the third aqueous solution.
According to clause 36,

The carbon dioxide processing unit

an inlet located below the water surface of the third aqueous solution in the third accommodation space and through which carbon dioxide gas flows; and

The water electrolysis system further includes; a communication port located below the inlet and formed to communicate with the first accommodating space in the third accommodating space.
According to clause 29,

The cathode part

The water electrolysis system further includes a first outlet located above the water surface of the first aqueous solution accommodated in the first accommodation space and discharging hydrogen gas generated during discharge.
According to clause 36,

The carbon dioxide processing unit

The water electrolysis system is located above the water surface of the third aqueous solution in the third accommodation space and further includes a second outlet through which the non-ionized carbon dioxide gas is discharged during discharge.
According to clause 36,

The carbon dioxide processing unit

A water electrolysis system further comprising a carbon dioxide circulation supply unit that resupplies the non-ionized carbon dioxide gas to the third aqueous solution in the third accommodation space.
According to clause 29,

A water electrolysis system wherein the first aqueous solution or the second aqueous solution is an alkaline aqueous solution containing alkaline metal ions.
According to clause 43,

A water electrolysis system in which alkaline metal ions in the second accommodation space move to the first accommodation space through an ion exchange membrane.
a first electrode unit including a first aqueous solution accommodated in the first accommodating space, and a first electrode at least partially submerged in the first aqueous solution;

a second electrode unit including a second aqueous solution accommodated in a second receiving space, and a second electrode at least partially submerged in the second aqueous solution;

a first connection portion including a connecting passage connecting the first accommodating space and the second accommodating space, and a cation exchange membrane provided in the connecting passage;

a third electrode unit including a third aqueous solution accommodated in a third accommodating space, and a third electrode at least partially submerged in the third aqueous solution;

a second connection portion including a connecting passage connecting the second accommodating space and the third accommodating space, and an exchange membrane provided in the connecting passage; and

It includes a power supply connected to the second electrode and the third electrode,

When discharging, carbon dioxide gas flows into the first aqueous solution in the first electrode unit, and hydrogen ions (H + ) and bicarbonate ions (HCO 3 - ) are generated by the reaction of the first aqueous solution and the carbon dioxide gas. generated, the second electrode unit generates electrons (e - ) through an oxidation reaction, and the first electrode unit combines the hydrogen ions (H + ) with the electrons (e - ) generated in the second electrode unit to form hydrogen. A composite secondary battery characterized in that gas (H 2 ) is generated.
According to clause 45,

A reactor for producing calcium carbonate (CaCO 3(S) );

A first inlet connecting the first accommodation space and the reactor and introducing bicarbonate ions (HCO 3 - ) from the first accommodation space into the reactor;

A second inlet connected to the reactor and introducing calcium ions (Ca 2+ ) into the reactor; and

A third inlet connecting the third accommodating space and the reactor and injecting the remaining liquid after the calcium carbonate (CaCO 3(S) ) production reaction into the third accommodating space; producing calcium carbonate (CaCO 3(S) ) including a A composite secondary battery containing parts.
According to clause 45,

A composite secondary battery further comprising a carbon dioxide treatment unit that communicates with the first accommodating space and includes a fourth aqueous solution accommodated in the fourth accommodating space.
According to clause 47,

The carbon dioxide processing unit

A composite secondary battery in which un-ionized carbon dioxide gas among the carbon dioxide gas flowing into the fourth accommodation space is separated from the fourth aqueous solution to prevent it from being supplied to the first electrode unit.
According to clause 47,

The carbon dioxide processing unit,

A composite secondary battery that separates the un-ionized carbon dioxide gas using the difference in specific gravity from the fourth aqueous solution.
According to clause 47,

The carbon dioxide processing unit

an inlet located below the water surface of the fourth aqueous solution in the fourth accommodation space and through which carbon dioxide gas flows; and

A composite secondary battery further comprising; a communication port located below the inlet and formed to communicate with the first accommodating space in the fourth accommodating space.
According to clause 45,

The first electrode part

The composite secondary battery further includes a first outlet located above the water surface of the first aqueous solution accommodated in the first accommodation space and discharging hydrogen gas generated during discharge.
According to clause 47,

The carbon dioxide processing unit

The composite secondary battery further includes a second outlet located above the water surface of the fourth aqueous solution in the fourth accommodation space, through which the un-ionized carbon dioxide gas is discharged during discharge.
According to clause 47,

The carbon dioxide processing unit

A composite secondary battery further comprising a carbon dioxide circulation supply unit that re-supplies the non-ionized carbon dioxide gas to the fourth aqueous solution in the fourth accommodating space.
According to clause 45,

The third electrode part

A composite secondary battery in which an oxygen evolution reaction (OER) and a chlorine evolution reaction (CER) occur when power is supplied from a power supply device.
According to clause 45,

The third electrode part

The composite secondary battery further includes a second outlet located above the water surface of the third aqueous solution accommodated in the third accommodation space and discharging oxygen gas and chlorine gas generated when power is supplied to the power supply device.
According to clause 45,

The third electrode part

A composite secondary battery further comprising a residual liquid circulation supply unit that re-supplies the residual liquid after reaction to the fourth aqueous solution in the fourth accommodating space when power is supplied to the power supply device.