Electrolysis device

Abstract

The present invention relates to an electrolysis device comprising: an electrolysis cell having a gas diffusion layer, a cathode, a separation membrane, an anode, and an electrolyte solution; and an acid solution tank connected outside the electrolytic cell through a discharge flow path for discharging the product from the cathode, wherein the separation membrane is a cationic separation membrane.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2023-0077536 filed in the Korean Intellectual Property Office on June 16, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] The invention relates to an electrolysis device for electrochemical reduction of carbon dioxide. Background Art

[0005] Carbon dioxide is a greenhouse gas that causes global warming and should therefore be reduced. As methods for reducing carbon dioxide, methods such as capture, chemical conversion or electrochemical conversion are known. In the above methods, the electrochemical conversion method allows precise control of the components to produce other synthetic gases and is therefore more economical than simply removing carbon dioxide. In addition, carbon dioxide can be electrolyzed with water to obtain carbon monoxide, ethylene, methane, formic acid, formates, various hydrocarbons and organic substances such as aldehydes or alcohols.

[0006] The process of electrochemically decomposing carbon dioxide is similar to the technology of electrolyzing water. However, since the activity of the electrochemical reaction is improved in a strong alkaline environment, a certain concentration of KOH aqueous solution is usually used as the electrolyte solution. When an electric current is applied while water is supplied to the anode, the water is decomposed into hydrogen ions and electrons, and oxygen is produced at the same time. The electrons are transferred to the cathode through an external wire, and the hydrogen ions are transferred to the cathode through an ion-selective separator. At this time, the transferred electrons react with the carbon dioxide and water supplied to the cathode, and then decompose into carbon monoxide and hydroxide ions (OH - ), and the generated hydroxide ions react with the hydrogen ions (H + ) reacts to produce water, thereby being in an electrically neutral state. Through the above process, the electrochemical decomposition reaction of carbon dioxide is completed. At this time, the water supplied together with carbon dioxide reacts with the transferred electrons (which are separated from the carbon monoxide production reaction) and is electrolyzed to produce hydrogen, and at the same time, hydroxide ions are produced. Such a reaction of water and electrons can be said to be in a competitive relationship with the carbon monoxide production reaction. Since the reaction is an electrochemical reaction, the amount of carbon monoxide generated and the ratio of hydrogen / carbon dioxide can be easily controlled by controlling the voltage.

[0007] Meanwhile, in a typical electrolysis device, OH is produced by a side reaction in the cathode during the CO2 electrolysis process. - , and OH - Reacts again with supplied carbon dioxide to produce carbonate (HCO3 -). Therefore, a typical electrolysis device has a problem in that the supplied carbon dioxide produces carbonate without being converted into a desired product, which results in a loss of carbon dioxide. In addition, a typical electrolysis device has a problem in that the electrolysis efficiency is reduced because the carbonate diffuses to the anode by passing through the anion exchange membrane and produces carbon dioxide by an oxidation reaction in the anode.

[0008] (Patent Document 001) KR 10-2018-0133688A Summary of the invention

[0009] Technical issues

[0010] An object to be achieved by the present invention is to provide an electrolysis device in which carbon dioxide is separated again from carbonate produced by a side reaction during electrolysis of carbon dioxide, thereby preventing the loss of carbon dioxide converted to carbonate and improving the yield of the product.

[0011] Technical Solution

[0012] The present invention provides an electrolysis device.

[0013] (1) The present invention provides an electrolysis device, comprising: an electrolytic cell having a gas diffusion layer, a cathode, a separator membrane, an anode and an electrolyte solution; and an acid solution storage tank connected outside the electrolytic cell through a discharge flow path for discharging a product from the cathode, wherein the separator membrane is a cationic separator membrane.

[0014] (2) In the above (1), the present invention provides an electrolysis device, wherein the acid solution storage tank contains an acidic solution containing one or more selected from phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, citric acid and oxalic acid.

[0015] (3) In (1) or (2) above, the present invention provides an electrolysis device, wherein the electrolyte solution is an aqueous solution comprising one or more selected from the following: Cs2CO3, CsHCO3, Cs2SO4, CsCl, CsNO3, K2CO3, KHCO3, K2SO4, K3PO4, KCl, KNO3, Na2CO3, NaHCO3, Na2SO4, Na3PO4, NaCl and NaNO3.

[0016] (4) In any one of (1) to (3) above, the present invention provides an electrolysis device, wherein the electrolysis cell is a zero-gap membrane electrode assembly cell in which a gas diffusion layer, a cathode, a separator membrane and an anode in which an anode liquid flow path is formed are stacked sequentially.

[0017] (5) In any one of (1) to (4) above, the present invention provides an electrolysis device, wherein products produced by the electrolysis reaction in the cathode are transferred to an acid solution storage tank through an exhaust flow path, wherein the products include carbon monoxide, water vapor and salt.

[0018] (6) In the above (5), the present invention provides an electrolysis apparatus in which carbon dioxide generated from salt in an acid solution storage tank is supplied to an electrolytic cell.

[0019] (7) In (5) or (6) above, the present invention provides an electrolysis device wherein the salt is a carbonate.

[0020] (8) In any one of (1) to (7) above, the present invention provides an electrolysis device, wherein the electrolysis device electrolyzes carbon dioxide.

[0021] (9) In (8) above, the present invention provides the electrolysis apparatus, wherein the carbon dioxide is supplied in a state containing water vapor when supplied to the electrolytic cell.

[0022] (10) In any one of (1) to (9) above, the present invention provides an electrolysis device, wherein the electrolysis device electrolyzes carbon dioxide to produce one or more selected from the following: carbon monoxide, ethylene, methane, formic acid, hydrocarbons, aldehydes and alcohols.

[0023] Beneficial Effects

[0024] The electrolysis device of the present invention connects the acid solution storage tank to the electrolytic cell, thereby separating carbon dioxide from salt produced by a side reaction in the acid solution storage tank, and thus can prevent the loss of carbon dioxide.

[0025] In addition, the electrolysis device of the present invention reduces the loss of carbon dioxide and thus can improve the electrolysis efficiency of carbon dioxide, thereby increasing the yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a carbon dioxide electrolysis device according to the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, the present invention will be described in more detail to facilitate understanding of the present invention. In this case, it will be understood that the words or terms used in the specification and claims should not be interpreted as having the meaning defined in the commonly used dictionary. It will be further understood that, based on the inventors can appropriately define the meaning of the words or terms to best illustrate the principles of the present invention, the words or terms should be interpreted as having the meaning consistent with its meaning in the context of the relevant technology and the technical concept of the present invention.

[0028] The terms used herein are for describing exemplary embodiments only and are not intended to limit the present invention. Unless the context clearly indicates otherwise, a singular expression includes a plural expression.

[0029] It will also be understood that the terms “comprises,” “comprising,” or “having,” when used in this specification, specify the presence of stated features, numbers, steps, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, elements, or combinations thereof.

[0030] The present invention provides an electrolysis device, which includes: an electrolytic cell having a gas diffusion layer, a cathode 13, a separator membrane 15, an anode 11 and an electrolyte solution; and an acid solution storage tank 20 connected outside the electrolytic cell through a discharge flow path 30 for discharging products from the cathode 13, wherein the separator membrane 15 is a cationic separator membrane.

[0031] According to one embodiment of the present invention, the electrolysis device can be used in all fields of electrochemical conversion, and the electrolysis device can be a fuel cell, a device capable of producing useful chemical substances by electrochemical conversion such as water electrolysis, or a device that can be used for reducing and converting carbon dioxide and NOx. Specifically, the electrolysis device can be an electrochemical conversion device that converts carbon dioxide into carbon monoxide and ethylene.

[0032] As described in the background art, an electrolytic cell having a typical structure in which an electrolyte solution flows in front of a cathode has a problem in that OH generated by a side reaction during a reduction process of carbon dioxide is - It reacts with carbon dioxide again to produce carbonate (HCO3 - ), and thus lose carbon dioxide, wherein this problem can be solved by flowing an acidic electrolyte solution in front of the cathode, but in this case, additional resistance occurs due to the acidic electrolyte solution, which produces another problem of voltage increase. In addition, as a separator included in the carbon dioxide electrolyzer, an anion exchange membrane is mainly used, and the anion exchange membrane is fast in ion transfer and thus has excellent carbon dioxide conversion efficiency, but has very low mechanical strength, and in addition, carbonate passes through the anion exchange membrane and diffuses to the anode and produces carbon dioxide by an oxidation reaction in the anode, so that there is a problem of reduced efficiency of electrolysis.

[0033] Therefore, the inventors of the present invention have developed an electrolysis device of the present invention, in which the carbonate produced does not diffuse into the anode 11, and the carbon dioxide is separated again from the carbonate produced, thereby reducing the loss of the supplied carbon dioxide. Specifically, the electrolysis device includes an electrolytic cell and an acid solution storage tank 20 connected to the outside of the electrolytic cell. The electrolysis device includes a cathode 13 and an anode 11, wherein a gas diffusion layer may be arranged near the cathode 13, and a separator 15 and an electrolyte solution may be arranged between the cathode 13 and the anode 11. In addition, the electrolysis device according to the present invention may include an electrolytic cell having a structure of a zero-gap membrane electrode assembly to be described later. The electrolytic cell having a structure of a zero-gap membrane electrode assembly has a structure in which the electrolyte solution does not flow in front of the cathode 13, and the electrolyte solution flows only in front of the anode 11, so that the additional problem of voltage increase during the electrolysis reaction can be solved. In addition, the electrolytic cell may include a cation exchange membrane to prevent the produced carbonate from being transported to the anode 11.

[0034] Figure 1 is a schematic diagram of a carbon dioxide electrolysis device according to the present invention.

[0035] According to one embodiment of the present invention, the cathode 13 is connected to a supply line for supplying reactants and an exhaust flow path 30 for discharging products produced after electrolysis. The reactant may be carbon dioxide, and the carbon dioxide may be in a gaseous state and may contain water vapor at about 40° C. to 60° C. In addition, the product is produced by electrolyzing carbon dioxide and may be one or more selected from the following: carbon monoxide, ethylene, methane, formic acid, hydrocarbons, aldehydes, and alcohols. Unreacted carbon dioxide, water vapor, and carbonates produced by side reactions may also be discharged together with the products discharged from the exhaust flow path 30.

[0036] Reference Figure 1 The acid solution storage tank 20 is connected to the discharge flow path 30, and carbon dioxide can be separated again from carbonate by the acid solution contained in the acid solution storage tank 20. Specifically, the hydrogen ions (H + ) and carbonate (HCO3 - ) can react with each other to produce water and carbon dioxide. In addition, the acid solution storage tank 20 can include an acidic solution containing one or more selected from phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, citric acid and oxalic acid. The acidic solution can be used to regenerate carbon dioxide by reacting with the produced carbonate radical, and compared with a typical electrolysis device, the electrolysis device of the present invention also includes an acid solution storage tank 20 to regenerate carbon dioxide from carbonate radical, and therefore the electrolysis efficiency can be improved and the amount of carbon dioxide loss to carbonate radical can be reduced.

[0037] According to one embodiment of the present invention, the separator 15 is a cation separator 15, and specifically, it can be a Nafion separator 15. The cation separator 15 can be used to prevent the carbonate generated from the cathode 13 from diffusing to the anode 11. In addition, if the separator 15 is an anion separator 15, the carbonate diffuses to the anode 11, which is not conducive to the transportation of the carbonate to the acid solution storage tank 20, which may reduce the overall electrolysis efficiency and may increase the loss of carbon dioxide.

[0038] According to one embodiment of the present invention, the electrolyte solution may be an acidic or neutral electrolyte solution, and may contain cations (Na + , K + or Cs + ). For example, it can be Cs2CO3, CsHCO3, Cs2SO4, CsCl, CsNO3, K2CO3, KHCO3, K2SO4, K3PO4, KCl, KNO3, Na2CO3, NaHCO3, Na2SO4, Na3PO4, NaCl or NaNO3.

[0039] According to one embodiment of the present invention, the electrolytic cell may be a zero-gap membrane electrode assembly cell in which a gas diffusion layer, a cathode 13, a separator membrane 15, and an anode 11 having a liquid flow path of the anode 11 are sequentially stacked. Specifically, in order to improve the driving voltage and current efficiency, the zero-gap membrane electrode assembly may be formed into a very thin valve shape in which a gas diffusion layer, a cathode 13, a separator membrane 15, and an anode 11 having a liquid flow path of the anode 11 are sequentially stacked.

[0040] A typical electrolytic cell has a gap structure shape because the electrodes and the separator are separated from each other by a gap of several millimeters, while the above-mentioned zero gap is a sandwich-shaped electrolytic cell in which there is no gap between the electrodes and the separator because the cathode electrode and the anode and cathode electrodes are in contact with each other with the separator inserted therebetween. The zero gap electrolytic cell can reduce the solution ion resistance caused by the presence of the electrolyte, and can reduce the mass transfer resistance increased by the generated gas when implementing large-area electrodes.

[0041] In addition, the electrolyte solution flowing to the cathode 13 is called the cathode 13 liquid, and the electrolyte solution flowing to the anode 11 is called the anode 11 liquid, and the zero-gap membrane electrode assembly may not contain the cathode 13 liquid, but may only contain the anode 11 liquid. The zero-gap membrane electrode assembly minimizes the gap between the cathode 13, the anode 11 and the separator 15, and therefore, can have the advantages of being able to accelerate the transport of ions, reduce overvoltage and increase current efficiency. In addition, in this case, a separator may be provided on both sides of the zero-gap membrane electrode assembly to form a groove.

[0042] According to one embodiment of the present invention, the exhaust flow path 30 transports the product produced in the cathode 13 by the electrolytic reaction to the acid solution storage tank 20, and the product may include carbon dioxide, carbon monoxide, water vapor and salt. In addition, the carbon dioxide produced in the acid solution storage tank 20 may be supplied to the electrolytic cell.

[0043] The carbon dioxide produced by separating carbon dioxide from carbonate in the acid solution storage tank 20 can be supplied back to the cathode 13 through the supply pipeline. The electrolysis device of the present invention separates carbon dioxide from carbonate through the acid solution storage tank 20 and circulates carbon dioxide to the electrolytic cell to reduce the loss of carbon dioxide and improve the electrolysis efficiency.

[0044] In the following, the decomposition principle of the electrolysis device and the components of the electrolysis device will be described.

[0045] Electrolysis refers to the decomposition of materials by redox reactions by applying a direct current voltage to carry out decomposition reactions that do not occur spontaneously. The anode is an oxidizing electrode that oxidizes water to produce oxygen and hydrogen ions. The hydrogen ions produced in the anode are transferred to the cathode through an electrolyte solution, and the cathode is a reducing electrode, where the reactants introduced to the cathode can react with the electrons and hydrogen ions transferred from the anode and produce products. In addition, a separator can be provided between the anode and the cathode. The separator itself can be composed of an inert material that does not participate in the electrochemical reaction, but provides a path that allows ions to transfer between the anode and the cathode, and can be used to separate the physical contact between the anode and the cathode.

[0046] In addition, the anode and cathode of the electrolysis device of the present invention may each include a catalyst layer. In addition, in the cathode region, the water vapor supplied together with the carbon dioxide generates a reduction product through an electric reduction reaction on the surface of the cathode. Therefore, the cathode may include a gas diffusion layer to uniformly supply humidified carbon dioxide gas to the cathode region. If the cathode includes a hydrophobic gas diffusion layer, the supplied carbon dioxide can be smoothly diffused, distributed and supplied to the catalyst layer of the cathode. In addition, the hydrophobic gas diffusion layer effectively prevents moisture from condensing, thereby making the supply of carbon dioxide continuous and uniform, and at the same time, allowing the electrolysis reaction to proceed smoothly. In addition, the catalyst layer may have a surface with a porous structure, etc. to well exert gas permeability characteristics on the surface.

[0047] According to one embodiment of the present invention, the anode may include a catalyst active in the electrolysis of water, and the catalyst layer of the anode may include one or more selected from the following: Pt, Au, Pd, Ir, Ag, Rh, Ru, Ni, Al, Mo, Cr, Cu, Ti, W, alloys thereof, or mixed metal oxides such as Ta2O5, IrO2, etc., for oxygen generation reaction. Specifically, in the electrolysis device of the present invention, the anode may include titanium (Ti) coated with iridium oxide (IrO2).

[0048] In addition, since the carbon dioxide reduction reaction occurring in the cathode competes with the hydrogen generation reaction, the voltage required for the hydrogen generation reaction is high, and a catalyst active in the carbon dioxide reduction reaction may be included. The catalyst layer of the cathode may include one or more selected from the following: Sn, Sn alloy, Al, Au, Ag, C, Cd, Co, Cr, Cu, Cu alloy, Ga, Hg, In, Mo, Nb, Ni, NiCo2O4, Ni alloy, Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn and mixtures thereof. Specifically, in the electrolysis device of the present invention, the cathode may include silver (Ag).

[0049] In addition, the separator membrane as described above may include a cation exchange membrane (CEM), and specifically, may be a Nafion exchange membrane. The cation exchange membrane may be used as a membrane to prevent the reduced substances generated by catalysis in the cathode from being transferred to the anode and oxidized, and may be a membrane to inhibit the transmission of anions and allow cations such as hydrogen ions (H + ) of the transport separation phase.

[0050] In addition, the electrolyte solution as described above can be an electrolyte solution according to the present invention, and specifically, it can be an acidic electrolyte solution, and more specifically, it can be an aqueous solution containing cesium bicarbonate. The electrolyte solution composition can include an electrolyte solution of 0.1M to 15.0M, preferably 0.25M to 10.0M. The concentration of the electrolyte solution is related to the production efficiency of the product (the production efficiency of the target product relative to the applied current density) and the voltage. The higher the concentration of the electrolyte solution, the lower the voltage, the required voltage or the overvoltage generated, but in order to minimize the increase in the production of the manufacturing cost and the other products caused by the side reaction, the above conditions are preferred.

[0051] In addition, the gas diffusion layer can use a porous body utilizing carbon materials, such as carbon fiber cloth, carbon fiber felt, carbon fiber paper, etc.; or a metal porous body made of a thin metal plate with a mesh structure, such as expanded metal, metal mesh, etc., and in the electrolysis device of the present invention, the gas diffusion layer can use carbon fiber cloth.

[0052] According to one embodiment of the present invention, the electrolysis device can be used in all fields requiring electrochemical conversion, and in particular, allows the desired products to be obtained by electrochemically decomposing carbon dioxide, and specifically, the electrolysis device can electrolyze carbon dioxide to produce one or more selected from the following: carbon monoxide, ethylene, methane, formic acid, hydrocarbons, aldehydes and alcohols.

[0053] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention can be presented in many different forms and is not limited to the embodiments set forth herein.

[0054] Example 1

[0055] The carbon dioxide electrolysis device having the following operating conditions is operated. The carbon dioxide electrolysis device is operated, which is a device having an anode, a cation separator (type: 212), a zero-gap structured membrane electrode assembly in which a cathode and a gas diffusion layer are sequentially stacked, and which includes an acid solution storage tank connected to the cathode and the outside of the membrane electrode assembly and filled with an acid solution (85%, H3PO4).

[0056] Reaction current density: 100mA / cm 2 (Constant current operation)

[0057] Reaction voltage: 1V to 4V

[0058] Reaction temperature: 40℃

[0059] Reaction pressure: 1atm (atmospheric pressure)

[0060] Anode catalyst: IrO2 on Ti mesh

[0061] Cathode catalyst: Silver powder

[0062] Electrode area: 100cm 2

[0063] Gas diffusion layer: Sigracet 39BB

[0064] Anolyte solution: 1.0M CsHCO3 (25ml / min)

[0065] Cathode reactant: 40℃ humidified CO2 gas (200ccm)

[0066] 40℃ humidified CO2 gas supply flow rate: 200ml / min

[0067] Example 2

[0068] The carbon dioxide electrolysis device was operated under the same conditions as in Example 1, except that the reaction current density was 200 mA / cm 2 .

[0069] Example 3

[0070] The carbon dioxide electrolysis device was operated under the same conditions as in Example 1, except that the reaction current density was 300 mA / cm 2 .

[0071] Comparative Example 1

[0072] The carbon dioxide electrolysis apparatus was operated under the same conditions as in Example 1, except that an anion exchange membrane was used instead of a cation exchange membrane and the acid solution storage tank was not included.

[0073] Comparative Example 2

[0074] The carbon dioxide electrolysis device was operated under the same conditions as in Example 2, except that an anion exchange membrane was used instead of a cation exchange membrane and the acid solution storage tank was not included.

[0075] Comparative Example 3

[0076] The carbon dioxide electrolysis device was operated under the same conditions as in Example 3, except that an anion exchange membrane was used instead of a cation exchange membrane and the acid solution storage tank was not included.

[0077] Comparative Example 4

[0078] The carbon dioxide electrolysis apparatus was operated under the same conditions as in Example 1, except that the acid solution storage tank was not included.

[0079] Comparative Example 5

[0080] The carbon dioxide electrolysis device was operated under the same conditions as in Example 2, except that the acid solution storage tank was not included.

[0081] Comparative Example 6

[0082] The carbon dioxide electrolysis device was operated under the same conditions as in Example 3, except that the acid solution storage tank was not included.

[0083] Experimental example

[0084] The product produced by the carbon dioxide reduction reaction performed by the carbon dioxide electrolysis device according to each of Examples 1 to 3 and Comparative Examples 1 to 6 was analyzed by gas chromatography. At this time, the amount of carbon dioxide initially introduced was compared with the amount of carbon dioxide produced, and the amount of carbon dioxide lost without being electrochemically reduced was measured. In addition, the Faraday efficiency of carbon monoxide and hydrogen was measured according to the following measurement method, and the measured characteristics are each described in the following Table 1.

[0085] (1) Carbon dioxide loss rate (CO2 loss, %)

[0086] The gas composition at the exhaust flow path was measured by gas chromatography (GC) analysis. The flow rate (mL / min) of the exhaust gas was multiplied by the percentage (%) of carbon dioxide measured by GC analysis to measure the flow rate (Q) of CO2 exhausted after electrochemical conversion. CO2 .f), and compare it with the initial input flow (Q CO2 .i) Compared to measure the total amount of CO2 used (CO2 use, %). Since the conversion rate of CO during the CO2 reduction reaction is 1:1, assuming that the flow rate of carbon monoxide gas (Qco) measured by GC analysis is equal to the amount of CO2 converted electrochemically (CO2 conversion, %), the remainder obtained by subtracting the conversion amount from the amount of CO2 used is calculated as CO2 loss. The measured value is calculated by the following equation 1.

[0087] [Equation 1]

[0088]

[0089] CO2 loss (%) CO2 use (%) CO2 conversion (%)

[0090] (2) Carbon monoxide Faraday efficiency (%)

[0091] The gas composition at the exhaust flow path was measured by gas chromatography (GC) analysis. In addition, the Faraday efficiency was calculated by the following equation.

[0092] [Equation 2]

[0093]

[0094] In Equation 2 above, Q is the flow rate at the exhaust flow path, F is the Faraday constant, p is the pressure, T is the measured temperature, and R is the ideal gas constant. 总 is the value of the total current applied over time, and the current i relative to the product 产物 is the volume of the gas V measured by GC analysis 产物 The calculated value.

[0095] (3) Hydrogen Faraday efficiency (%)

[0096] The hydrogen Faraday efficiency was measured and calculated in the same manner as the carbon monoxide Faraday efficiency (2) described above.

[0097] [Table 1]

[0098]

[0099] Referring to Table 1, in the case of Examples 1 to 3 including the acid solution storage tank, the carbon monoxide Faraday efficiency was maintained at the same level, and at the same time, the carbon dioxide loss rate was significantly low, compared to Comparative Examples 1 to 6 not including the acid solution storage tank.

[0100] That is, the electrolysis device of the present invention separates carbon dioxide from carbonate again by including an acid solution storage tank, and therefore, can significantly reduce the loss of carbon dioxide converted into carbonate and has high electrolysis efficiency. In contrast, in the case of Comparative Examples 1 to 3 using anion exchange membranes or Comparative Examples 4 to 6 using cation exchange membranes but not including an acid solution storage tank, it can be seen that the amount of carbon dioxide lost due to conversion into carbonate is large, so that the electrolysis efficiency is reduced.

[0101] 11: Anode

[0102] 13: Cathode

[0103] 15: Separator membrane

[0104] 20: Acid solution storage tank

[0105] 30: Discharge flow path

[0106] 60: Gas-liquid separator

Claims

1. An electrolysis device, comprising: an electrolytic cell comprising a gas diffusion layer, a cathode, a separator, an anode and an electrolyte solution; and an acid solution storage tank connected outside the electrolyzer via a discharge flow path for discharging the product from the cathode, The separator membrane is a cationic separator membrane.

2. The electrolysis device according to claim 1, wherein the acid solution storage tank contains an acidic solution containing one or more selected from phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, citric acid and oxalic acid.

3. The electrolysis device according to claim 1, wherein the electrolyte solution is an aqueous solution comprising one or more selected from the group consisting of Cs2CO3, CsHCO3, Cs2SO4, CsCl, CsNO3, K2CO3, KHCO3, K2SO4, K3PO4, KCl, KNO3, Na2CO3, NaHCO3, Na2SO4, Na3PO4, NaCl and NaNO3.

4. The electrolysis device according to claim 1, wherein the electrolysis cell is a zero-gap membrane electrode assembly cell in which the gas diffusion layer, the cathode, the separator, and an anode in which an anode liquid flow path is formed are sequentially stacked.

5. The electrolysis device according to claim 1, wherein products generated by the electrolysis reaction in the cathode are transported to the acid solution storage tank through the exhaust flow path, wherein the products include carbon monoxide, water vapor, and salt. 6 . The electrolysis device according to claim 5 , wherein carbon dioxide generated from the salt in the acid solution storage tank is supplied to the electrolysis cell.

7. The electrolysis device according to claim 5, wherein the salt is a carbonate.

8. The electrolysis device according to claim 1, wherein the electrolysis device electrolyzes carbon dioxide. 9 . The electrolysis device according to claim 8 , wherein the carbon dioxide is supplied in a state containing water vapor when supplied to the electrolytic cell.

10. The electrolysis device according to claim 1, wherein the electrolysis device electrolyzes carbon dioxide to produce one or more selected from the group consisting of carbon monoxide, ethylene, methane, formic acid, hydrocarbons, aldehydes, and alcohols.

Images