US20240150906A1

US20240150906A1 - Electrolytic cell and electrolytic cells in series, which can be used as chloralkali electrolytic cell and process co2

Info

Publication number: US20240150906A1
Application number: US18/314,362
Authority: US
Inventors: Hao-Ming Chen; Tai-Lung Chen; Wan-Tun HUNG; Yu-Cheng Chen; Kuo-Ming Huang; Fu-Da YEN; Che-Jui LIAO
Original assignee: Formosa Plastics Corp; National Taiwan University NTU
Current assignee: Formosa Plastics Corp; National Taiwan University NTU
Priority date: 2022-11-03
Filing date: 2023-05-09
Publication date: 2024-05-09
Also published as: TWM646259U

Abstract

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.

Description

RELATED APPLICATIONS

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 Invention

The present disclosure relates to an electrolytic cell and an electrolytic cell in series.

Description of Related Art

Carbon 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.

SUMMARY

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 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.

BRIEF DESCRIPTION OF THE DRAWINGS

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.

FIG. 1 is a schematic diagram of a side view of an electrolytic cell according to some embodiments of the present disclosure.

FIG. 2 is a schematic diagram of an exploded view of an electrolytic cell according to some embodiments of the present disclosure.

FIG. 3 is a schematic diagram of the back side of the cathode compartment of an electrolytic cell according to some embodiments of the present disclosure.

FIG. 4 is a schematic diagram of a sectional view of the anode mesh, the cation exchange membrane, the flow channel element, the gas diffusion electrode, the elastic mesh, and the conductive mesh of an electrolytic cell according to some embodiments of the present disclosure.

FIG. 5 is a schematic diagram of a perspective view of the anode compartment of an electrolytic cell according to some embodiments of the present disclosure.

FIG. 6 is a schematic diagram of a side view of an electrolytic cell in series according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

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.
Refer to FIGS. 1 to 3 . FIG. 1 is a schematic diagram of a side view of the electrolytic cell 100 according to some embodiments of the present disclosure. FIG. 2 is a schematic diagram of an exploded view of the electrolytic cell 100 according to some embodiments of the present disclosure. FIG. 3 is a schematic diagram of the back side of the cathode compartment 102 of the electrolytic cell 100 according to some embodiments of the present disclosure. The electrolytic cell 100 includes the cathode compartment 102, the anode compartment 104, and the cation exchange membrane 103, in which the cation exchange membrane 103 is between the cathode compartment 102 and the anode compartment 104. In some embodiments, a length 102L of the cathode compartment 102 is from 10 cm to 40 cm, for example, 10 cm, 20 cm, 30 cm, and 40 cm; a width 102W of the cathode compartment 102 is from 10 cm to 40 cm, for example, 10 cm, 20 cm, 30 cm, and 40 cm; and a thicknesses of 102T of the cathode compartment 102 is from 5 cm to 20 cm, for example, 5 cm, 10 cm, 15 cm, and 20 cm. In some embodiments, a length 104L of the anode compartment 104 is from 10 cm to 40 cm, for example, 10 cm, 20 cm, 30 cm, and 40 cm; a width 104W of the anode compartment 104 is from 10 cm to 40 cm, for example, 10 cm, 20 cm, 30 cm, and 40 cm; and a thickness 104T of the anode compartment 104 is from 5 cm to 20 cm, for example, 5 cm, 10 cm, 15 cm, and 20 cm.
Continually refer to FIGS. 1 to 3 . The electrolytic cell 100 further includes a cathode gasket 106, an anode gasket 108, and a plurality of screws 110. The cathode gasket 106 and the anode gasket 108 are respectively between the cation exchange membrane 103 and the cathode compartment 102 and the cation exchange membrane 103 and the anode compartment 104. The cathode compartment 102, the anode compartment 104, the cathode gasket 106, and the anode gasket 108 respectively have a plurality of holes 102H, a plurality of holes 104H, a plurality of holes 106H, and a plurality of holes 108H. The holes 102H, the holes 104H, the holes 106H, and the holes 108H are aligned with each other, in which the screws 110 inside the holes combine the cathode compartment 102, the anode compartment 104, the cathode gasket 106, and the anode gasket 108 together. The cathode compartment 102 and the anode compartment 104 respectively have a cave 102A and cave 104A, and the cave 102A and the cave 104A depress in the direction facing each other, so when the cathode compartment 102, the anode compartment 104, the cathode gasket 106, and the anode gasket 108 are combined with the screws 110, the cation exchange membrane 103 can be located inside a space 112 formed by connecting the cave 102A and the cave 104A (not shown in the view of FIG. 1 , and details please refer to a schematic diagram of an exploded view in FIG. 2 ). The space 112 also contains the anode mesh 114 of the anode compartment 104, and the flow channel element 116, the gas diffusion electrode 118, the elastic mesh 120, and the conductive mesh 122 of the cathode compartment 102. The above-mentioned details will be explained in the following.
Continually refer to a sectional view of the electrolytic cell 100 in FIG. 4 , which includes the anode mesh 114, the cation exchange membrane 103, the flow channel element 116, the gas diffusion electrode 118, the elastic mesh 120, and the conductive mesh 122 according to some embodiments of the present disclosure. A distance D between the anode mesh 114 and the gas diffusion electrode 118 is substantially equal to the sum of a first thickness T1 of the cation exchange membrane 103 and a second thickness T2 of the flow channel element 116. Therefore, the distance D between the anode mesh 114 and the gas diffusion electrode 118 is minimized to reduce the resistance, thereby reducing the voltage to perform the electrolysis and saving electricity use. In some embodiments, the first thickness T1 of the cation exchange membrane 103 is from 0.1 mm to 0.6 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, and 0.6 mm. In some embodiments, the second thickness T2 of the flow channel element 116 is from 0.1 mm to 0.8 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, and 0.8 mm. In some embodiments, the distance D between the anode mesh 114 and the gas diffusion electrode 118 is from 0.2 mm to 1.4 mm, for example, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, and 1.4 mm.
Continually refer to FIGS. 1 to 3 . The cathode compartment 102 and the anode compartment 104 respectively further include a conductive structure 1028 with unlimited numbers and a conductive structure 1048 with unlimited numbers, in which the conductive structure 102B and the conductive structure 104B are respectively in direct contact with the conductive mesh 122 of the cathode compartment 102 and the anode mesh 114 of the anode compartment. The above-mentioned details will be explained in the following. The cathode compartment 102 further includes a gas inlet 102C with unlimited numbers, a liquid inlet 102D with unlimited numbers, a gas outlet 102E with unlimited numbers, and a liquid outlet 102F with unlimited numbers, which are connecting to the outer surface of the electrolytic cell 100, and the anode compartment 104 further includes a liquid inlet 104C with unlimited numbers and a gas/liquid outlet 104D with unlimited numbers, which are connecting to the outer surface of the electrolytic cell 100. The above-mentioned details will be explained in the following. The anode compartment 104 further includes an inclined plate 124 with unlimited numbers and a gas-liquid separation chamber 126 with unlimited numbers, in which the inclined plate 124 is adjacent to the conductive structure 104B, and the gas-liquid separation chamber 126 is located above the inclined plate 124. The above-mentioned details will be explained in the following.
Refer to FIGS. 2 and 4 for the detailed explanation of the flow channel element 116, the liquid inlet 102D, and the liquid outlet 102F of the cathode compartment 102. The flow channel element 116 is between the cation exchange membrane 103 and the gas diffusion electrode 118, and is in direct contact with the cation exchange membrane 103 and the gas diffusion electrode 118. The flow channel element 116 has a plurality of flow channels 116A (e.g., flow channels made in metal) arranged parallel to each other. The liquid inlet 102D and the liquid outlet 102F are respectively located on the upper side and the lower side of the flow channel element 116, and respectively connect the flow channel element 116. The cathode electrolyte enters the flow channel element 116 through the liquid inlet 102D, and the cathode reaction occurs on the surface where the flow channel element 116 and the gas diffusion electrode 118 are in direct contact. The cathode electrolyte then leaves the cathode compartment 102 through the liquid outlet 102F. Compared with placing the cathode electrolyte in a single chamber, flowing the cathode electrolyte in a plurality of flow channels 116A reduces the resistance of the cathode electrolyte and the resistance caused by the bubbles in the cathode electrolyte.
Refer to FIGS. 2, 3, and 4 for the detailed explanation of the gas diffusion electrode 118, the gas inlet 102C, and the gas outlet 102E of the cathode compartment 102. The gas diffusion electrode 118 is between the flow channel element 116 and the elastic mesh 120, and includes a catalyst layer 118A, a hydrophilic layer 118B, and a hydrophobic layer 118C. The gas inlet 102C and the gas outlet 102E are respectively located on the opposite side of the cathode compartment 102. When the gas reactant enters the cathode compartment 102 through the gas inlet 102C, the gas reactant diffuses to the surface where the gas diffusion electrode 118 and the flow channel element 116 are in direct contact for the cathode reaction to occur. The gas product exits the cathode compartment 102 through the gas outlet 102E. The catalyst layer 118A includes a catalyst 128 and is in direct contact with the flow channel element 116. The hydrophilic layer 1188 is between the catalyst layer 118A and the hydrophobic layer 118C. The hydrophilic layer 118B increases the contact between the cathode electrolyte in the flow channel element 116 and the gas diffusion electrode 118 to avoid too little catalyst 128 reacting with the cathode electrolyte to result in excessive voltage use. The Hydrophilic layer 118B may also increase the adhesion between the catalyst layer 118A and the hydrophilic layer 1188. The hydrophobic layer 118C prevents the cathode electrolyte in the flow channel element 116 from entering the side of the gas diffusion electrode 118 opposite to the flow channel element 116 to avoid the cathode electrolyte affecting the concentration and the rate of the gas reactant that diffuses to the gas diffusion electrode 118, thereby improving the electrolysis efficiency. The hydrophobic layer 118C also makes the gas product formed in the electrolysis quickly desorbs from the gas diffusion electrode 118, which therefore avoids the deterioration of electrolysis efficiency caused by the gas product residue, and avoids the enhancement of the electrolysis voltage that causes electrical waste. Because of the good electrolysis efficiency, electrical waste is avoided even if the size of the gas diffusion electrode 118 is increased. In some embodiments, the area of the gas diffusion electrode 118 is from 0.02 m²to 2.9 m², for example, 0.04 m², 0.28 m², or 2.85 m². In some embodiments, the hydrophilic layer 118B is a carbon black layer, including carbon black 130, and the hydrophobic layer 118C is a carbon fiber layer, including carbon fiber 132. In some embodiments, the thickness ratio of the hydrophilic layer 118B to the hydrophobic layer 118C is 1:1. In some embodiments, a thickness T3 of the hydrophilic layer 118B and the hydrophobic layer 118C is 0.3 mm. In some embodiments, the catalyst 128 includes cobalt, silver, iron, a combination of iron and ruthenium dioxide, zinc, copper, or combinations thereof. In some embodiments, the flow rate of the gas reactant entering the gas inlet 102C is from 30 sccm to 100 sccm.
Refer to FIGS. 2 and 4 for the detailed explanation of the elastic mesh 120 of the cathode compartment 102. The elastic mesh 120 is formed and braided by a plurality of metal wires 134 (e.g., nickel wires), in which a wire diameter of the plurality of metal wires 134 is from 0.05 mm to 0.5 mm, for example, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm. The thickness of the elastic mesh 120 is from 1 mm to 10 mm, for example, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, and 10 mm, and the elastic mesh 120 is in direct contact with the gas diffusion electrode 118. The elastic mesh 120 has compressibility, for example, up to 2000 mmH₂O. The elastic mesh 120 makes the gas diffusion electrode 118, the flow channel element 116, the cation exchange membrane 103, and the anode mesh 114 combine with each other more closely, thereby improving the electrolysis efficiency and reducing the resistance between the anode mesh 114 and the gas diffusion electrode 118.
Refer to FIGS. 1, 2, and 4 for the detailed explanation of the conductive mesh 122 and the conductive structure 1028 of the cathode compartment 102. The conductive mesh 122 is between the conductive structure 102B and the elastic mesh 120. The conductive structure 102B is connected to the power supply (not drawn) to conduct the electron flow to the conductive mesh 122, the elastic mesh 120, and the gas diffusion electrode 118 sequentially, where the cathode electrolysis reaction occurs on the gas diffusion electrode 118. The conductive mesh 122 also has the role of supporting the elastic mesh 120. In some embodiments, the conductive mesh 122 is a nickel mesh with a thickness of 1.0 mm. In some embodiments, the conductive structure 1028 is a nickel plate with a thickness of 1.2 mm.
Refer to FIGS. 2 and 4 for the detailed explanation of the anode mesh 114 and the conductive structure 104B of the anode compartment 104. The anode mesh 114 is between the conductive structure 1048 and the cation exchange membrane 103. The conductive structure 1048 is connected to the power supply (not shown) to conduct the current through the conductive structure 104B to the anode mesh 114, where the anode electrolysis reaction occurs on the anode mesh 114. In some embodiments, the anode mesh 114 is a ruthenium-iridium titanium electrode.
Refer to FIGS. 2 and 5 for the detailed explanation of the liquid inlet 104C, the gas/liquid outlet 104D, the inclined plate 124, and the gas-liquid separation chamber 126 of the anode compartment 104, in which FIG. 5 is a schematic diagram of a perspective view of the anode compartment 104 of the electrolytic cell 100 according to some embodiments of the present disclosure. The gas-liquid separation chamber 126 is located above the anode compartment 104 and has an opening 126H located above the inclined plate 124. The gas-liquid separation chamber 126 further includes a debubbling mesh 136 inside the gas-liquid separation chamber 126. The inclined plate 124 is located below the gas-liquid separation chamber 126 and an angle A between the inclined plate 124 and the anode mesh 114 is from 3 degrees to 10 degrees, for example, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, and 10 degrees. The liquid inlet 104C is located below the inclined plate 124. The gas/liquid outlet 104D is located below the anode compartment 104 and has a pipe 138 connected to the gas-liquid separation chamber 126. The anode electrolyte enters the anode compartment 104 from the liquid inlet 104C located below the anode compartment 104, and the anode electrolysis reaction occurs on the anode mesh 114. The diluted anode electrolyte after the reaction quickly returns to the bottom of the anode compartment 104 through the inclined plate 124 and mixes with the anode electrolyte that has just entered the anode compartment 104, so that the anode electrolyte in the entire anode compartment 104 is mixed evenly to improve the electrolysis efficiency. The homogeneous mixing of the anode electrolyte also makes the cations exchange evenly on the cation exchange membrane, thereby prolonging the lifetime using the cation exchange membrane. Since the gas produced in the electrolysis remains easily on the top of the anode compartment 104, when the gas is exhausted from the electrolyte cell in a large amount, it slaps the cation exchange membrane 103 and causes the cation exchange membrane 103 damage and/or the gas remained in the electrolyte cell increases the resistance value of the electrolyte cell. When the anode electrolyte containing the gas product enters the gas-liquid separation chamber 126 through the opening 126H, the debubbling mesh 136 of the gas-liquid separation chamber 126 reduces the size of the bubble of the gas, thereby avoiding the gas damaging the cation exchange membrane 103 and avoiding the gas increasing the resistance. The bubble of the gas with the reduced size exits from the anode compartment 104 through the gas/liquid outlet 104D with the anode electrolyte.
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 FIG. 6 for the detailed explanation of the electrolytic cell in series. FIG. 6 is a schematic diagram of a side view of the electrolytic cell in series 200 according to some embodiments of the present disclosure. The first electrolytic cell 202 and the second electrolytic cell 204 are substantially the above-mentioned electrolytic cell 100, so the details may not be repeated herein. The second anode compartment 204A of the second electrolytic cell 204 is located on the side of the first electrolytic cell 202 having the first cathode compartment 202B, so the first electrolytic cell 202 and the second electrolytic cell 204 are electrically connected in a series connection. In some embodiments, the gas inlet, the liquid inlet, the gas outlet, and the liquid outlet of the first cathode compartment 202B of the first electrolytic cell 202B respectively have a pipeline (not shown) connected to the gas inlet, the liquid inlet, the gas outlet, and the liquid outlet of the second cathode compartment 204B of the second electrolytic cell 204. In some embodiments, the gas inlet and the gas/liquid outlet of the first anode compartment 202A of the first electrolytic cell 202 respectively have a pipeline (not shown) connected to the gas inlet and the gas/liquid outlet of the second anode compartment 204A of the second electrolytic cell 204. The electrolytic cells in the electrolytic cell in series have the above-mentioned good electrolysis efficiency and increase the electrolysis output through the series connection, thereby applicable to large-scale commercial and industrial purposes.
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

What is claimed is:

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.