ELECTROLYTIC CELL AND ELECTROLYTIC CELLS IN SERIES, WHICH CAN BE USED AS CHLORALKALI ELECTROLYTIC CELL AND PROCESS CO2
An electrolytic cell includes a cation exchange membrane, a cathode compartment, and an anode compartment. The cathode compartment includes a gas diffusion electrode and a flow channel element, in which the flow channel element is between the cation exchange membrane and the gas diffusion electrode, and has a plurality of flow channels arranged in parallel with each other. The anode compartment includes an anode mesh, in which the cation exchange membrane is between the anode mesh and the flow channel element. A distance between the anode mesh and the gas diffusion electrode is substantially equal to the sum of a first thickness of the cation exchange membrane and a second thickness of the flow channel element. The novel electrolytic cell can combine with a chloralkali electrolytic cell to deal with gaseous CO2 and produce products, e.g., synthesis gas, for other purposes.
This application claims priority to Taiwan Application Serial Number 111212041, filed Nov. 3, 2022, which is herein incorporated by reference in its entirety.
BACKGROUND Field of InventionThe present disclosure relates to an electrolytic cell and an electrolytic cell in series.
Description of Related ArtCarbon dioxide (CO2) is a common greenhouse gas that causes global warming. Electrolyzing carbon dioxide and converting it into syngas (carbon monoxide and hydrogen gas), formic acid, ethylene, ethanol, and so on can not only achieve carbon reduction but also recycle the product. However, the method of electrolyzing carbon dioxide with the solid oxide electrolytic cell requires a high temperature of 750° C. to 1300° C. The high demand for the equipment does not meet the operating cost. Dissolving carbon dioxide gas into the electrolyte to form a solution containing carbonate ion or bicarbonate ion and then electrolyzing the solution are limited by the solubility of carbon dioxide, so when the electricity increases, there may be not enough carbon dioxide to dissolve and to electrolyze. Therefore, it is necessary to develop an electrolytic cell that can directly electrolyze gas, has good electrolysis efficiency, saves electricity, and meets the economic costs.
SUMMARYThe present disclosure relates to an electrolytic cell. The electrolytic cell includes a cation exchange membrane, a cathode compartment, and an anode compartment. The cathode compartment includes a gas diffusion electrode and a flow channel element, in which the flow channel element is between the cation exchange membrane and the gas diffusion electrode, and the flow channel element has a plurality of flow channels arranged in parallel with each other. The anode compartment includes an anode mesh, in which the cation exchange membrane is between the anode mesh and the flow channel element, and a distance between the anode mesh and the gas diffusion electrode is substantially equal to the sum of a first thickness of the cation exchange membrane and a second thickness of the flow channel element.
In some embodiments, the first thickness of the cation exchange membrane is from 0.1 mm to 0.6 mm, and the second thickness of the flow channel element is from 0.1 mm to 0.8 mm.
In some embodiments, the gas diffusion electrode includes a catalyst layer, a hydrophilic layer, and a hydrophobic layer, the hydrophilic layer is between the catalyst layer and the hydrophobic layer, and the catalyst layer is in direct contact with the flow channel element.
In some embodiments, the catalyst layer includes cobalt, silver, iron, a combination of iron and ruthenium dioxide, zinc, copper, or combinations thereof.
In some embodiments, the hydrophilic layer is a carbon black layer, and the hydrophobic layer is a carbon fiber layer.
In some embodiments, the cathode compartment further includes an elastic mesh, the elastic mesh is formed and braided by a plurality of nickel wires, a wire diameter of the plurality of nickel wires is from 0.05 mm to 0.5 mm, a thickness of the elastic mesh is from 1 mm to 10 mm, and the elastic mesh is in direct contact with the gas diffusion electrode.
In some embodiments, the cathode compartment further includes a gas inlet and a liquid inlet, and the anode compartment further includes a liquid inlet.
In some embodiments, the anode compartment further includes an inclined plate, and an angle between the inclined plate and the anode mesh is from 3 degrees to 10 degrees.
In some embodiments, the anode compartment further includes a gas-liquid separation chamber, and the gas-liquid separation chamber has an opening above the inclined plate.
In some embodiments, the gas-liquid separation chamber includes a debubbling mesh.
The present disclosure also relates to an electrolytic cell in series. The electrolytic cell in series includes at least two above-mentioned electrolytic cells formed in series.
The present disclosure yet also relates to an electrolytic cell. The electrolytic cell includes a cation exchange membrane, a cathode compartment, and an anode compartment. The cathode compartment includes a flow channel element and a gas diffusion electrode, in which the flow channel element is between the cation exchange membrane and the gas diffusion electrode, the flow channel element has a plurality of flow channels arranged in parallel with each other, the gas diffusion electrode includes a catalyst layer, a hydrophilic layer, and a hydrophobic layer, the hydrophilic layer is between the catalyst layer and the hydrophobic layer, and the catalyst layer is in direct contact with the flow channel element. The cation exchange membrane is between the anode compartment and the cathode compartment.
In some embodiments, the catalyst layer includes cobalt, silver, iron, a combination of iron and ruthenium dioxide, zinc, copper, or combinations thereof.
In some embodiments, the hydrophilic layer is a carbon black layer, and the hydrophobic layer is a carbon fiber layer.
In some embodiments, the cathode compartment further includes an elastic mesh, the elastic mesh is formed and braided by a plurality of nickel wires, a wire diameter of the plurality of nickel wires is from 0.05 mm to 0.5 mm, a thickness of the elastic mesh is from 1 mm to 10 mm, and the elastic mesh is in direct contact with the gas diffusion electrode.
When reading the accompanying figures of the present disclosure, it is recommended to understand the various aspects of the present disclosure from the following description. It is noted that according to standard industry practice, the sizes of various features may not be drawn to scale. For the clarity of the discussion, the sizes of various features may be increased or decreased arbitrarily.
To make the description of the present disclosure more detailed and complete, the following is an illustrative description of the aspects of the embodiment and the specific embodiment. It is not intended to limit the embodiment of the present disclosure to only one form. Embodiments of the present disclosure may be combined or replaced by each other under beneficial instances. Other embodiments may be added without further statement or explanation.
In addition, spatially relative terms, such as below and above, describe the relationship between one component or feature and another component or feature in the present disclosure. In addition to the orientation described in the figures, the spatially relative terms are intended to cover the different orientations when the device is used or operated. For example, the device may be otherwise oriented (e.g., rotating 90 degrees or in other directions), and the spatially relative terms of the present disclosure may be interpreted accordingly. In the present disclosure, unless otherwise specified, the same reference number in different figures means the same or similar components formed in the same or similar materials by the same or similar methods.
The present disclosure relates to an electrolytic cell. The electrolytic cell includes a cation exchange membrane, a cathode compartment, and an anode compartment. The cathode compartment includes a gas diffusion electrode and a flow channel element, in which the flow channel element is between the cation exchange membrane and the gas diffusion electrode, and the flow channel element has a plurality of flow channels arranged parallel to each other. The anode compartment includes an anode mesh, in which the cation exchange membrane is between the anode mesh and the flow channel element. A distance between the anode mesh and the gas diffusion electrode is substantially equal to the sum of a first thickness of the cation exchange membrane and a second thickness of the flow channel element. The electrolytic cell of the present disclosure will be explained in detail in the following. The electrolytic cell of the present disclosure can be used as a chloralkali electrolytic cell and can electrolyze carbon dioxide gas to generate syngas used for other purposes and the carbon dioxide gas is recycled.
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In some embodiments, sodium hydroxide aqueous solution is a cathode electrolyte and it enters the flow channel element 116 of the cathode compartment 102 through the liquid inlet 102D, carbon dioxide gas is a gas reactant and it enters the cathode compartment 102 through the gas inlet 102C, and sodium chloride aqueous solution is an anode electrolyte and it enters the anode compartment 104 through the liquid inlet 104C. The cathode electrolysis reaction occurs on the gas diffusion electrode 118 to electrolyze water in the sodium hydroxide aqueous solution to hydrogen gas and to electrolyze carbon dioxide and water in the sodium hydroxide aqueous solution to carbon monoxide. The Faradaic efficiency of converting carbon dioxide to carbon monoxide is more than 85%, and the molar ratio of hydrogen gas to carbon monoxide is from 1:9 to 9:1. The anode electrolysis reaction occurs on the anode mesh 114 to electrolyze the chloride ions in the sodium chloride aqueous solution to chlorine gas. The electrolysis reduces carbon dioxide to achieve carbon reduction and produces syngas (carbon monoxide and hydrogen gas) and chlorine gas, which can be reused, for example, as a fuel in power generation, an industrial raw material, and so on. In addition, the hydroxide ion formed after electrolyzing the sodium hydroxide aqueous solution may combine with the sodium ion which enters the flow channel element 116 from the anode compartment 104 through the cation exchange membrane 103 to form sodium hydroxide, thereby increasing the concentration of the sodium hydroxide aqueous solution in the flow channel element 116. The sodium hydroxide aqueous solution with increased concentration can be reused for other industrial purposes. In some embodiments, the concentration of sodium hydroxide aqueous solution entering from the liquid inlet 102D is 30%, and the concentration of sodium hydroxide aqueous solution leaving from the liquid outlet 102F is 32%.
The present disclosure also relates to an electrolytic cell in series. The electrolytic cell in series is formed by connecting at least two above-mentioned electrolytic cells in series. Refer to
The electrolytic cell and the electrolytic cell in series in the present disclosure can directly electrolyze gas, and whether the reactant is gas or liquid, the reactant is mixed uniformly to improve the electrolysis efficiency and avoid insufficient electrolysis to cause voltage consumption greater than expected, which increases the electricity waste. The electrolytic cell and the electrolytic cell in series in the present disclosure have small resistance values to save electricity, save energy, be environmentally friendly, and meet economic costs. The electrolytic cell and the electrolytic cell in series in the present disclosure have electrolytic Faradaic efficiency of up to 90%, so when the size of the electrolytic cell increases, the electrolytic efficiency is still good to save electricity consumption, thereby being suitable for large-scale commercial or industrial use. The electrolytic cell and the electrolytic cell in series in the present disclosure meet the economic cost by having a long lifetime of the electrolytic cell and having good electrolytic efficiency at a temperature from 70° C. to 80° C. The electrolytic cell and the electrolytic cell in series in the present disclosure can electrolyze carbon dioxide gas and sodium chloride aqueous solution and use sodium hydroxide aqueous solution as cathode electrolyte to produce syngas (carbon monoxide and hydrogen gas), chlorine gas, and sodium hydroxide aqueous solution with an increased concentration to reduce carbon dioxide gas and reuse the product.
The present disclosure is described in detail in some embodiments. However, other embodiments may be feasible. Therefore the description of the embodiments contained in the present disclosure is not intended to limit the scope and spirit of the attached claims.
For one skilled in the art, they may modify and change the present disclosure without deviating from the spirit and scope of the present disclosure. As long as the above-mentioned modifications and changes fall within the scope and spirit of the attached claims, these modifications and changes are covered by the present disclosure.
Claims
1. An electrolytic cell, comprising:
- a cation exchange membrane;
- a cathode compartment, comprising a gas diffusion electrode and a flow channel element, wherein the flow channel element is between the cation exchange membrane and the gas diffusion electrode, and the flow channel element has a plurality of flow channels arranged in parallel with each other; and
- an anode compartment, comprising an anode mesh, wherein the cation exchange membrane is between the anode mesh and the flow channel element, and a distance between the anode mesh and the gas diffusion electrode is substantially equal to the sum of a first thickness of the cation exchange membrane and a second thickness of the flow channel element.
2. The electrolytic cell of claim 1, wherein the first thickness of the cation exchange membrane is from 0.1 mm to 0.6 mm, and the second thickness of the flow channel element is from 0.1 mm to 0.8 mm.
3. The electrolytic cell of claim 1, wherein the gas diffusion electrode comprises a catalyst layer, a hydrophilic layer, and a hydrophobic layer, the hydrophilic layer is between the catalyst layer and the hydrophobic layer, and the catalyst layer is in direct contact with the flow channel element.
4. The electrolytic cell of claim 3, wherein the catalyst layer comprises cobalt, silver, iron, a combination of iron and ruthenium dioxide, zinc, copper, or combinations thereof.
5. The electrolytic cell of claim 3, wherein the hydrophilic layer is a carbon black layer, and the hydrophobic layer is a carbon fiber layer.
6. The electrolytic cell of claim 1, wherein the cathode compartment further comprises an elastic mesh, the elastic mesh is formed and braided by a plurality of nickel wires, a wire diameter of the plurality of nickel wires is from 0.05 mm to 0.5 mm, a thickness of the elastic mesh is from 1 mm to 10 mm, and the elastic mesh is in direct contact with the gas diffusion electrode.
7. The electrolytic cell of claim 1, wherein the cathode compartment further comprises a gas inlet and a liquid inlet, and the anode compartment further comprises a liquid inlet.
8. The electrolytic cell of claim 1, wherein the anode compartment further comprises an inclined plate, and an angle between the inclined plate and the anode mesh is from 3 degrees to 10 degrees.
9. The electrolytic cell of claim 8, wherein the anode compartment further comprises a gas-liquid separation chamber, and the gas-liquid separation chamber has an opening above the inclined plate.
10. The electrolytic cell of claim 9, wherein the gas-liquid separation chamber comprises a debubbling mesh.
11. An electrolytic cell in series, comprising at least two electrolytic cells of claim 1 formed in series.
12. An electrolytic cell, comprising:
- a cation exchange membrane;
- a cathode compartment, comprising a flow channel element and a gas diffusion electrode, wherein the flow channel element is between the cation exchange membrane and the gas diffusion electrode, the flow channel element has a plurality of flow channels arranged in parallel with each other, the gas diffusion electrode comprises a catalyst layer, a hydrophilic layer, and a hydrophobic layer, the hydrophilic layer is between the catalyst layer and the hydrophobic layer, and the catalyst layer is in direct contact with the flow channel element; and
- an anode compartment, wherein the cation exchange membrane is between the anode compartment and the cathode compartment.
13. The electrolytic cell of claim 12, wherein the catalyst layer comprises cobalt, silver, iron, a combination of iron and ruthenium dioxide, zinc, copper, or combinations thereof.
14. The electrolytic cell of claim 12, wherein the hydrophilic layer is a carbon black layer, and the hydrophobic layer is a carbon fiber layer.
15. The electrolytic cell of claim 12, wherein the cathode compartment further comprises an elastic mesh, the elastic mesh is formed and braided by a plurality of nickel wires, a wire diameter of the plurality of nickel wires is from 0.05 mm to 0.5 mm, a thickness of the elastic mesh is from 1 mm to 10 mm, and the elastic mesh is in direct contact with the gas diffusion electrode.
Type: Application
Filed: May 9, 2023
Publication Date: May 9, 2024
Inventors: Hao-Ming CHEN (New Taipei City), Tai-Lung CHEN (New Taipei City), Wan-Tun HUNG (Kaohsiung City), Yu-Cheng CHEN (Kaohsiung City), Kuo-Ming HUANG (Kaohsiung City), Fu-Da YEN (Kaohsiung City), Che-Jui LIAO (Kaohsiung City)
Application Number: 18/314,362