Device and method for coupling hydrogen production by water electrolysis of proton exchange membrane with carbon dioxide trapping

Abstract

The invention provides a proton exchange membrane water electrolysis hydrogen production coupled carbon dioxide capture device, which comprises an electrolysis device and a carbon dioxide capture device, the electrolysis device comprises a proton exchange membrane, an anode assembly, a cathode assembly, a power supply, a first solution pool, a second solution pool, an intermediate solution pool and a third solution pool, the anode assembly and the cathode assembly are arranged on the two sides of the proton exchange membrane and connected with the positive electrode and the negative electrode of the power source respectively, the anode assembly is provided with a first inlet and a first outlet, the first inlet is communicated with the first solution pool and provided with a liquid inlet pump, the first outlet is communicated with the second solution pool, one side of the second solution pool is communicated with the first solution pool, and the other side of the second solution pool is communicated with the second solution pool. The cathode assembly is provided with a second outlet, the second outlet is communicated with the intermediate solution tank and is provided with a hydrogen outlet, the intermediate solution tank is provided with a second inlet, is communicated with the third solution tank and is provided with a liquid inlet pump, and the third solution tank is communicated with the second solution tank. The invention further discloses a method.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon dioxide capture, and in particular relates to a device and method for coupling proton exchange membrane water electrolysis with carbon dioxide capture to produce hydrogen. Background Art

[0002] In the face of the intensification of global climate challenges, reducing greenhouse gas emissions has become a common goal of the international community and is shaping a new trend in global economic development. At the same time, with the rapid development of hydrogen energy technology, the technology of producing hydrogen by electrolysis of water is gradually becoming one of the main ways to obtain hydrogen. Despite this, the existing carbon dioxide capture technology still faces challenges such as complex processes, strict conditions and low capture efficiency. In addition, the large amount of energy consumption required in the regeneration process is also an important factor restricting the development of carbon capture technology. At present, the technology of hydrogen production by electrolysis of water mainly focuses on the production of hydrogen, but fails to fully utilize the potential energy resources brought about by the change of solution during the electrolysis process.

[0003] The prior art proposes a method for capturing carbon dioxide while producing hydrogen by electrolyzing water. This method uses the acid-base solution produced during the electrolysis process to capture carbon dioxide, and removes sulfur dioxide in the flue gas through air oxidation, thereby improving the carbon dioxide capture efficiency. However, this method has the following problems. The salt bridge or diaphragm used will increase the ion transfer impedance, resulting in the need to apply a higher voltage to maintain the same current during the electrolysis process, which will lead to reduced electrolysis efficiency and increased energy consumption. At the same time, it makes the device structure complex, requires additional space, and makes the structure non-compact, which affects the space utilization efficiency of the system and brings inconvenience to certain application scenarios.

[0004] In order to solve the above technical problems, the present invention designs a device and method for coupling proton exchange membrane water electrolysis to produce hydrogen and capture carbon dioxide. Summary of the invention

[0005] The present invention provides a device and method for producing hydrogen by electrolyzing water with a proton exchange membrane and capturing carbon dioxide, aiming to solve the problems of large ion transmission impedance and complex and uncompact device structure during electrolysis.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a device for producing hydrogen by electrolyzing water with a proton exchange membrane and coupling carbon dioxide capture, comprising an electrolysis device and a carbon dioxide capture device, wherein the electrolysis device comprises a proton exchange membrane, an anode assembly, a cathode assembly, a power supply, a first solution pool, a second solution pool, an intermediate solution pool and a third solution pool, wherein the anode assembly and the cathode assembly are arranged on both sides of the proton exchange membrane and are respectively connected to the positive electrode and the negative electrode of the power supply, the anode assembly is provided with a first inlet and a first outlet, the first inlet is connected to the first solution pool and is provided with a liquid inlet pump, the first outlet is connected to the second solution pool, one side of the second solution pool is connected to the first solution pool and the other side is connected to the carbon dioxide capture device, the cathode assembly is provided with a second outlet, the second outlet is connected to the intermediate solution pool and is provided with a hydrogen outlet, the intermediate solution pool is provided with a second inlet, and is connected to the third solution pool and is provided with a liquid inlet pump, and the third solution pool is connected to the second solution pool.

[0007] Based on the above technical solution, the anode assembly includes an anode porous transport layer and an anode bipolar plate, and the anode bipolar plate and the anode porous transport layer are arranged in sequence along a direction close to the proton exchange membrane.

[0008] Optionally, the cathode assembly includes a cathode porous transport layer and a cathode bipolar plate, and the cathode bipolar plate and the cathode porous transport layer are sequentially arranged in a direction close to the proton exchange membrane.

[0009] Based on the above technical solution, the side of the proton exchange membrane facing the anode assembly is coated with an anode catalyst layer, and the side of the proton exchange membrane facing the cathode assembly is coated with a cathode catalyst layer.

[0010] Based on the above technical solution, the first outlet is provided with an oxygen outlet.

[0011] Based on the above technical solution, liquid inlet valves are provided between the first solution pool and the second solution pool, and between the middle solution pool and the third solution pool.

[0012] Based on the above technical solution, the intermediate solution pool is provided with an exhaust port, and the exhaust port is provided with an exhaust valve.

[0013] In a second aspect, the present application provides a method for coupling proton exchange membrane water electrolysis with carbon dioxide capture, which is applied to a device for coupling proton exchange membrane water electrolysis with carbon dioxide capture as described in any of the above embodiments, and comprises the following steps: the first solution pool provides electrolyte to the anode through the first inlet under the action of a liquid inlet pump, and a second solution, oxygen and hydrogen ions are generated at the anode, the second solution enters the second solution pool, and the oxygen is discharged through the oxygen outlet; hydrogen ions and metal cations enter the cathode through the proton exchange membrane, and an intermediate solution and hydrogen are generated at the cathode, the hydrogen is discharged, and the intermediate solution enters the intermediate solution pool, and when the pH of the intermediate solution pool reaches a preset value, air is introduced into the intermediate solution pool through the second inlet, the intermediate solution reacts with the air to obtain a third solution, and the third solution enters the third solution pool; the third solution enters the second solution pool, and reacts with the second solution to generate a first solution and carbon dioxide, the carbon dioxide is captured by a carbon dioxide capture device, and the first solution enters the first solution pool for recycling.

[0014] On the basis of the above technical scheme, the method for coupling carbon dioxide capture with proton exchange membrane water electrolysis to produce hydrogen also includes introducing dust-free flue gas and then introducing air when the pH value of the intermediate solution pool reaches a preset value, and the intermediate solution reacts with the flue gas to generate HCO3 - and SO3 2- , the air will SO3 2- Oxidized to SO4 2- , HCO3 - Enter the second solution pool.

[0015] Based on the above technical solution, the electrolyte in the first solution pool is an aqueous solution of potassium sulfate, sodium sulfate, ammonium sulfate or magnesium sulfate.

[0016] Compared with the related art, the beneficial effects of the present invention are as follows: The present invention provides an electrolyte for the anode of an electrolysis device by arranging a first solution pool. The electrolyte enters the anode component through the first inlet under the action of a liquid inlet pump, and is electrolyzed to generate oxygen and hydrogen ions. Part of the hydrogen ions react with the first solution to obtain an acidic second solution. The second solution enters the second solution pool, and the oxygen is discharged. Part of the hydrogen ions and metal cations enter the cathode component through a proton exchange membrane, and hydrogen and an intermediate solution are generated at the cathode. The hydrogen is discharged, and the intermediate solution enters the intermediate solution pool. When the pH value of the intermediate solution pool reaches a preset value, air is introduced into the intermediate solution pool, and the alkaline intermediate solution reacts with the air to generate a third solution. The third solution enters the third solution pool, and then flows into the second solution pool, reacts with the second solution to generate a first solution and carbon dioxide. The carbon dioxide is captured by a carbon dioxide capture device, and the generated first solution flows into the first solution pool for recycling in subsequent electrolysis processes.

[0017] Compared with the existing technology, the setting of the proton exchange membrane can significantly reduce the ion transfer impedance during the electrolysis process. The improvement of the electrolytic cell allows the electrolyte to be recycled, thereby improving the electrolysis efficiency. It can also eliminate the complex structure of the salt bridge and diaphragm, simplify the system design, and make the entire device more compact. At the same time, it improves the carbon dioxide capture efficiency to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0019] Figure 1 It is a schematic structural diagram of a device for producing hydrogen by electrolyzing water with a proton exchange membrane and capturing carbon dioxide provided by the present invention; Figure 2 It is a flow chart of the method for producing hydrogen through proton exchange membrane water electrolysis coupled with carbon dioxide capture provided by the present invention.

[0020] In the figure: 1. electrolysis device; 11. proton exchange membrane; 12. anode assembly; 121. first inlet; 122. first outlet; 123. liquid inlet pump; 124. anode porous transport layer; 125. anode bipolar plate; 126. oxygen outlet; 13. cathode assembly; 131. second inlet; 132. second outlet; 133. cathode porous transport layer; 134. cathode bipolar plate; 14. first solution pool; 15. second solution pool; 16. third solution pool; 161. hydrogen outlet; 17. intermediate solution pool; 171. liquid inlet valve; 172. exhaust port; 173. exhaust valve; 174. air blocking valve; 18. power supply; 2. carbon dioxide capture device. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and examples: Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] Combination Figure 1 As shown, the embodiment of the present disclosure provides a device for producing hydrogen by electrolyzing water with a proton exchange membrane and coupling carbon dioxide capture, comprising an electrolysis device 1 and a carbon dioxide capture device 2, wherein the electrolysis device 1 comprises a proton exchange membrane 11, an anode assembly 12, a cathode assembly 13, a power supply 18, a first solution pool 14, a second solution pool 15, an intermediate solution pool 17 and a third solution pool 16, wherein the anode assembly 12 and the cathode assembly 13 are arranged on both sides of the proton exchange membrane 11 and are respectively connected to the positive electrode and the negative electrode of the power supply 18, wherein the anode assembly 12 is provided with a first inlet 121 and a first outlet 122, wherein the The first inlet 121 is connected to the first solution pool 14 and is provided with a liquid inlet pump 123. The first outlet 122 is connected to the second solution pool 15. One side of the second solution pool 15 is connected to the first solution pool 14, and the other side is connected to the carbon dioxide capture device 2. The cathode assembly 13 is provided with a second outlet 132. The second outlet 132 is connected to the intermediate solution pool 17 and is provided with a hydrogen outlet 161. The intermediate solution pool 17 is provided with a second inlet, and is connected to the third solution pool 16 and is provided with a liquid inlet pump 123. The third solution pool 16 is connected to the second solution pool 15.

[0025] In the device for producing hydrogen by electrolyzing water with a proton exchange membrane and capturing carbon dioxide provided in an embodiment of the present disclosure, a first solution pool 14 is provided to provide an electrolyte for the anode of the electrolysis device 1. The electrolyte enters the anode assembly 12 through the first inlet 121 under the action of the liquid inlet pump 123, and is electrolyzed to generate oxygen and hydrogen ions. Part of the hydrogen ions react with the first solution to obtain an acidic second solution. The second solution enters the second solution pool 15, and the oxygen is discharged. Part of the hydrogen ions and metal cations enter the cathode assembly 13 through the proton exchange membrane 11, and hydrogen and an intermediate solution are generated at the cathode. The hydrogen is discharged from the hydrogen outlet 161, and the intermediate solution enters the intermediate solution pool 17. Air is introduced into the intermediate solution pool 17, and the alkaline intermediate solution reacts with the air to generate a third solution. The third solution enters the third solution pool 16, and the third solution enters the second solution pool 15, and reacts with the second solution to generate a first solution and carbon dioxide. The carbon dioxide is captured by the carbon dioxide capture device 2, and the generated first solution flows into the first solution pool 14 for recycling in subsequent electrolysis processes.

[0026] Compared with the prior art, the provision of the proton exchange membrane 11 can significantly reduce the ion transfer impedance during the electrolysis process. The improvement of the electrolytic cell allows the electrolyte to be recycled, thereby improving the electrolysis efficiency. It can also eliminate the complex structure of the salt bridge and diaphragm, simplifying the system design and making the entire device more compact. At the same time, it improves the carbon dioxide capture efficiency to a certain extent.

[0027] Based on the above technical solution, the anode assembly 12 includes an anode porous transport layer 124 and an anode bipolar plate 125 , and the anode bipolar plate 125 and the anode porous transport layer 124 are sequentially arranged in a direction close to the proton exchange membrane 11 .

[0028] Optionally, the cathode assembly 13 includes a cathode porous transport layer 133 and a cathode bipolar plate 134 , and the cathode bipolar plate 134 and the cathode porous transport layer 133 are sequentially arranged in a direction close to the proton exchange membrane 11 .

[0029] Based on the above technical solution, the side of the proton exchange membrane 11 facing the anode assembly 12 is coated with an anode catalyst layer, and the side of the proton exchange membrane 11 facing the cathode assembly 13 is coated with a cathode catalyst layer.

[0030] Based on the above technical solution, the first outlet 122 is provided with an oxygen outlet 126 .

[0031] On the basis of the above technical solution, a liquid inlet valve 171 is provided between the first solution pool 14 and the second solution pool 15 and between the middle solution pool 17 and the third solution pool 16 .

[0032] Based on the above technical solution, the intermediate solution pool 17 is provided with an exhaust port 172, and the exhaust port 172 is provided with an exhaust valve 173. When air is introduced into the intermediate solution pool 17 through the second inlet 131, carbon dioxide reacts with the intermediate solution, the exhaust valve 173 is opened, and the remaining other gases are discharged from the intermediate solution pool 17 through the exhaust port 172.

[0033] Optionally, a gas blocking valve 174 is provided between the second outlet and the intermediate solution pool. When air is introduced into the intermediate solution pool 17 through the second inlet 131, the gas blocking valve 174 is closed to prevent gas from entering the cathode assembly 13 during ventilation and affecting the normal operation of the device.

[0034] Combination Figure 2 As shown, the embodiment of the present disclosure provides a method for coupling carbon dioxide capture by proton exchange membrane water electrolysis to produce hydrogen, which is applied to the device for coupling carbon dioxide capture by proton exchange membrane water electrolysis to produce hydrogen as described in any one of the above embodiments, comprising the following steps: S201, the first solution tank 14 provides electrolyte to the anode through the first inlet 121 under the action of the liquid inlet pump 123, and the second solution, oxygen and hydrogen ions are generated at the anode. The second solution enters the second solution tank 15, and the oxygen is discharged through the oxygen outlet 126; S202, hydrogen ions and metal cations enter the cathode through the proton exchange membrane 11, an intermediate solution and hydrogen are generated at the cathode, the hydrogen is discharged, the intermediate solution enters the intermediate solution pool, and when the pH of the intermediate solution pool reaches a preset value, air is introduced into the intermediate solution pool through the second inlet, the intermediate solution reacts with the air to obtain a third solution, and the third solution enters the third solution pool 16; S203, the third solution enters the second solution pool 15, reacts with the second solution to generate the first solution and carbon dioxide, the carbon dioxide is captured by the carbon dioxide capture device 2, and the first solution enters the first solution pool 14 for recycling.

[0035] Based on the above technical solution, the method of coupling carbon dioxide capture with water electrolysis by proton exchange membrane 11 also includes introducing dust-removed flue gas to the cathode through the second inlet 131 and then introducing air, and the intermediate solution reacts with the flue gas to generate HCO3 - and SO3 2- , the air will SO3 2- Oxidized to SO4 2- , HCO3 - Enter the second solution tank 15. This step can remove the effects of sulfur dioxide and particulate matter on the capture of carbon dioxide.

[0036] Specifically, the generated HCO3 -The solution enters the second solution pool 15 from the third solution pool 16 and reacts with the acidic second solution to generate the first solution and carbon dioxide. The carbon dioxide is captured by the carbon dioxide capture device 2. The first solution enters the first solution pool 14 for recycling.

[0037] Based on the above technical solution, the electrolyte in the first solution pool 14 is an aqueous solution of potassium sulfate, sodium sulfate, ammonium sulfate or magnesium sulfate, or an aqueous solution of other metal cation sulfates or nitrates that can pass through the proton exchange membrane. The present application does not limit the type of electrolyte.

[0038] The embodiment of the present disclosure takes potassium sulfate solution as an example. The first solution pool 14 provides potassium sulfate solution electrolyte to the anode through the first inlet 121 under the action of the liquid inlet pump 123, and generates sulfuric acid aqueous solution and oxygen at the anode. The sulfuric acid aqueous solution enters the second solution pool 15, and the oxygen is discharged through the oxygen outlet 126; hydrogen ions and potassium ions enter the cathode through the proton exchange membrane 11, and potassium hydroxide solution and hydrogen are generated at the cathode. The hydrogen is discharged from the hydrogen outlet 161, and the potassium hydroxide solution enters the intermediate solution pool 17. When the pH value of the solution in the intermediate solution pool reaches 10, air is introduced into the intermediate solution pool 17, and the potassium hydroxide solution reacts with carbon dioxide in the air to obtain potassium carbonate solution, and the potassium carbonate solution enters the third solution pool 16 through the liquid inlet valve 171; the potassium carbonate solution enters the second solution pool 15 through the liquid inlet valve 171, and reacts with sulfuric acid aqueous solution to generate potassium sulfate solution and carbon dioxide. The carbon dioxide is captured by the carbon dioxide capture device 2, and the potassium sulfate solution enters the first solution pool 14 for recycling.

[0039] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications made based on the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A device for producing hydrogen by proton exchange membrane electrolysis coupled with carbon dioxide capture, characterized in that: The invention comprises an electrolysis device and a carbon dioxide capture device. The electrolysis device comprises a proton exchange membrane, an anode assembly, a cathode assembly, a power supply, a first solution pool, a second solution pool, an intermediate solution pool and a third solution pool. The anode assembly and the cathode assembly are arranged on both sides of the proton exchange membrane and are respectively connected to the positive electrode and the negative electrode of the power supply. The anode assembly is provided with a first inlet and a first outlet. The first inlet is connected to the first solution pool and is provided with a liquid inlet pump. The first outlet is connected to the second solution pool. One side of the second solution pool is connected to the first solution pool and the other side is connected to the carbon dioxide capture device. The cathode assembly is provided with a second outlet. The second outlet is connected to the intermediate solution pool and is provided with a hydrogen outlet. The intermediate solution pool is provided with a second inlet, connected to the third solution pool and is provided with a liquid inlet pump. The third solution pool is connected to the second solution pool.

2. The device for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to claim 1, characterized in that: The anode assembly comprises an anode porous transport layer and an anode bipolar plate, and the anode bipolar plate and the anode porous transport layer are arranged in sequence along a direction close to a proton exchange membrane.

3. The device for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to claim 1, characterized in that: The cathode assembly comprises a cathode porous transport layer and a cathode bipolar plate, and the cathode bipolar plate and the cathode porous transport layer are arranged in sequence along a direction close to the proton exchange membrane.

4. The device for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to claim 1, characterized in that: The side of the proton exchange membrane facing the anode assembly is coated with an anode catalyst layer, and the side of the proton exchange membrane facing the cathode assembly is coated with a cathode catalyst layer.

5. The device for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to any one of claims 1 to 4, characterized in that: The first outlet is provided with an oxygen outlet.

6. The device for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to any one of claims 1 to 4, characterized in that: Liquid inlet valves are provided between the first solution pool and the second solution pool, and between the middle solution pool and the third solution pool.

7. The device for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to any one of claims 1 to 4, characterized in that: The intermediate solution pool is provided with an exhaust port, and the exhaust port is provided with an exhaust valve.

8. A method for coupling carbon dioxide capture by proton exchange membrane water electrolysis to produce hydrogen, applied to the device for coupling carbon dioxide capture by proton exchange membrane water electrolysis as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: The first solution tank provides electrolyte to the anode through the first inlet under the action of the liquid inlet pump, and the second solution, oxygen and hydrogen ions are generated at the anode. The second solution enters the second solution tank, and the oxygen is discharged through the oxygen outlet; Hydrogen ions and metal cations enter the cathode through the proton exchange membrane, an intermediate solution and hydrogen are generated at the cathode, the hydrogen is discharged, and the intermediate solution enters the intermediate solution pool. When the pH value of the intermediate solution pool reaches a preset value, air is introduced into the intermediate solution pool through the second inlet, and the intermediate solution reacts with the air to obtain a third solution, and the third solution enters the third solution pool; The third solution enters the second solution pool and reacts with the second solution to generate the first solution and carbon dioxide. The carbon dioxide is captured by the carbon dioxide capture device. The first solution enters the first solution pool for recycling.

9. The method for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to claim 8, characterized in that: It also includes the step of introducing dust-removed flue gas and then introducing air when the pH value of the intermediate solution pool reaches a preset value, and the intermediate solution reacts with the flue gas to generate HCO3 - and SO3 2- , the air will SO3 2- Oxidized to SO4 2- , HCO3 - Enter the second solution pool.

10. The method for producing hydrogen by proton exchange membrane water electrolysis coupled with carbon dioxide capture according to claim 8, characterized in that: The electrolyte in the first solution tank is an aqueous solution of potassium sulfate, sodium sulfate, ammonium sulfate or magnesium sulfate.

Images