Efficient hydrogen production system integrating proton conduction solid oxide electrolytic tank and oxygen pump

Abstract

The invention discloses a high-efficiency hydrogen production system integrating a proton conduction solid oxide electrolytic tank and an oxygen pump. The high-efficiency hydrogen production system comprises the proton conduction solid oxide electrolytic tank and the oxygen pump, the proton conduction solid oxide electrolytic tank comprises an oxygen electrode, a first electrolyte, a fuel electrode, a fuel electrode runner and an oxygen electrode runner; the oxygen pump comprises an oxygen pump anode, a second electrolyte, an oxygen pump cathode and an oxygen pump flow channel; the oxygen electrode flow channel is adjacent to the oxygen pump flow channel and is separated by the second electrolyte, the oxygen pump anode and the oxygen pump cathode; the oxygen electrode flow channel is used for introducing air containing water vapor; the oxygen pump flow channel is used for introducing nitrogen or inert gas; the fuel electrode runner is used for leading out generated pure hydrogen; according to the efficient hydrogen production system integrating the proton conduction solid oxide electrolytic tank and the oxygen pump, oxygen generated on the oxygen electrode side can be actively extracted and discharged through the oxygen pump, the oxygen partial pressure is remarkably reduced, the leakage current is reduced, the Faraday efficiency is improved, and the electrolysis voltage is reduced.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, specifically to a high-efficiency hydrogen production system that integrates a proton-conducting solid oxide electrolyzer and an oxygen pump. Background Technology

[0002] Proton-conducting solid oxide electrolyzers directly generate high-purity, dry hydrogen at the cathode, avoiding product gas mixing and subsequent complex separation / drying steps. Furthermore, compared to proton exchange membrane electrolyzers that rely on noble metal catalysts (such as platinum), proton-conducting solid oxide electrolyzers typically do not require noble metal catalysts, significantly reducing system catalyst costs and constituting a significant economic advantage.

[0003] However, experimental and theoretical simulation studies reveal that under oxidizing atmosphere conditions, proton-conducting electrolyte materials contain various point defects, mainly including proton defects. oxygen vacancies and electron holes The electron-hole concentration increases significantly with increasing ambient oxygen partial pressure. These migrating electrons and holes generate leakage current, leading to a decrease in the Faraday efficiency of the proton-conducting solid oxide electrolyzer.

[0004] For the oxygen electrode (anode) chamber of a proton-conducting solid oxide electrolyzer, the oxygen inside mainly comes from: firstly, the oxygen contained in the water vapor carrier gas (such as air) that is introduced, the concentration of which can be partially controlled by optimizing the composition of the carrier gas (e.g., using an inert gas or a low-oxygen gas); secondly, the oxygen generated and released by the electrolysis reaction itself at the oxygen electrode, however, the generation of which is unavoidable and difficult to suppress effectively.

[0005] To improve the current efficiency of proton-conductive solid oxide electrolyzers, integrating an oxygen pump on the oxygen electrode side is an effective solution. This oxygen pump, based on electrochemical principles, drives oxygen vacancies to migrate directionally from the anode side (high oxygen partial pressure) to the cathode side (low oxygen partial pressure) by applying a DC voltage across the dense oxygen-ion conductor electrolyte, thus achieving active oxygen transport. Coupling the oxygen pump to the oxygen electrode chamber of the proton-conductive solid oxide electrolyzer actively and efficiently removes oxygen generated during water electrolysis, significantly reducing the oxygen partial pressure in the anode chamber. This reduction in oxygen partial pressure directly leads to a decrease in the electron-hole concentration within the electrolyte, effectively suppressing leakage current and thereby improving the current efficiency of the proton-conductive solid oxide electrolyzer. Therefore, the integration of the oxygen pump with the proton-conductive solid oxide electrolyzer, actively regulating the oxygen electrode microenvironment to reduce oxygen partial pressure and suppress electron-hole conductivity, is a key path to improving the energy conversion efficiency of the electrolyzer and has significant technological value. Summary of the Invention

[0006] The purpose of this invention is to provide a highly efficient hydrogen production system that integrates a proton-conducting solid oxide electrolyzer and an oxygen pump. The oxygen pump actively extracts and discharges oxygen generated on the oxygen electrode side, significantly reducing oxygen partial pressure, reducing leakage current, improving Faraday efficiency, and lowering electrolysis voltage.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A highly efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump, comprising a proton-conducting solid oxide electrolyzer and an oxygen pump;

[0009] The proton-conducting solid oxide electrolytic cell includes an oxygen electrode, a first electrolyte, a fuel electrode, a fuel electrode channel, and an oxygen electrode channel.

[0010] The oxygen pump includes an oxygen pump anode, a second electrolyte, an oxygen pump cathode, and an oxygen pump flow channel;

[0011] The oxygen electrode flow channel is adjacent to the oxygen pump flow channel and is separated by the second electrolyte, the oxygen pump anode and the oxygen pump cathode.

[0012] The oxygen electrode channel is used to introduce air containing water vapor;

[0013] The oxygen pump channel is used to introduce nitrogen or inert gas;

[0014] The fuel electrode channel is used to export the generated pure hydrogen gas;

[0015] When power is supplied to the proton-conducting solid oxide electrolyzer, water vapor in the oxygen electrode channel is electrolyzed to generate oxygen in the oxygen electrode channel and pure hydrogen in the fuel electrode channel.

[0016] When a DC voltage is applied to the oxygen pump, the oxygen pump cathode reduces the oxygen in the oxygen electrode channel, eliminates oxygen vacancies and forms lattice oxygen ions. The lattice oxygen ions migrate to the oxygen pump anode via the second electrolyte. The lattice oxygen ions are oxidized to release oxygen and regenerate oxygen vacancies. The released oxygen is discharged into the oxygen pump channel to reduce the oxygen partial pressure in the oxygen electrode channel.

[0017] In a highly efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided by at least one embodiment of this disclosure, the first electrolyte is located between the oxygen electrode and the fuel electrode.

[0018] In a highly efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided by at least one embodiment of this disclosure, the second electrolyte is located between the oxygen pump anode and the oxygen pump cathode.

[0019] In a highly efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided by at least one embodiment of this disclosure, the second electrolyte is an oxygen ion conductor solid.

[0020] In the efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided in at least one embodiment of this disclosure, the proton-conducting solid oxide electrolyzer has a plate structure.

[0021] In the efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided in at least one embodiment of this disclosure, an oxygen electrode gas inlet and an oxygen electrode gas outlet are respectively provided on both sides of the oxygen electrode flow channel.

[0022] In the efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided in at least one embodiment of this disclosure, a nitrogen inlet and a nitrogen outlet are respectively provided on both sides of the oxygen pump flow channel.

[0023] In a high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided by at least one embodiment of this disclosure, the fuel electrode channel has a fuel electrode gas inlet and a fuel electrode gas outlet.

[0024] The efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump provided in at least one embodiment of this disclosure also includes a conductive current collector and an external power source.

[0025] The oxygen pump anode and oxygen electrode share the same conductive current collector, and the oxygen pump cathode is connected to the negative terminal of an external power source.

[0026] The beneficial effects of this invention are as follows: by using an electric field to drive the directional migration of oxygen vacancies in an ionic conductor, a net transfer of oxygen in space is achieved through electrode reactions, which significantly reduces the oxygen partial pressure, suppresses the generation of electron holes, thereby reducing leakage current, significantly improving the Faraday efficiency of the proton-conducting solid oxide electrolytic cell and reducing the electrolysis voltage. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of a proton-conducting solid oxide electrolytic cell.

[0029] Figure 2 This is a schematic diagram of the structure of a high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to the present invention.

[0030] Figure 3 The relationship between the electrolysis voltage and external current density of System 1 and System 2 under operating conditions is shown.

[0031] Figure 4 The oxygen partial pressure in the oxygen electrode flow channel of System 1 and System 2 under operating conditions is shown.

[0032] Figure 5 The Faraday efficiency of System 1 and System 2 under operating conditions is demonstrated.

[0033] In the picture:

[0034] 1. Oxygen electrode; 2. First electrolyte; 3. Fuel electrode; 4. Oxygen pump flow channel; 5. Oxygen pump anode; 6. Second electrolyte; 7. Oxygen pump cathode; 8. Oxygen electrode flow channel; 9. Proton-conducting solid oxide electrolytic cell; 10. Fuel electrode flow channel. Detailed Implementation

[0035] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments, not all embodiments.

[0036] Example

[0037] like Figure 1 and 2 As shown, this embodiment provides a high-efficiency hydrogen production system that integrates a proton-conducting solid oxide electrolyzer and an oxygen pump, including a proton-conducting solid oxide electrolyzer 9, an oxygen pump, a conductive current collector, and an external power supply.

[0038] In this embodiment, the proton-conducting solid oxide electrolyzer 9 includes an oxygen electrode 1, a first electrolyte 2, a fuel electrode 3, a fuel electrode channel 10, and an oxygen electrode channel 8.

[0039] Furthermore, the oxygen pump includes an oxygen pump anode 5, a second electrolyte 6, an oxygen pump cathode 7, and an oxygen pump flow channel 4;

[0040] Specifically, the oxygen electrode channel 8 is adjacent to the oxygen pump channel 4 and is separated by the second electrolyte 6, the oxygen pump anode 5 and the oxygen pump cathode 7.

[0041] Specifically, the oxygen electrode channel 8 is used to introduce air containing water vapor, and oxygen electrode gas inlet (not shown) and oxygen electrode gas outlet (not shown) are respectively provided on both sides of the oxygen electrode channel 8; the oxygen pump channel 4 is used to introduce nitrogen or inert gas, and nitrogen inlet (not shown) and nitrogen outlet (not shown) are respectively provided on both sides of the oxygen pump channel 4; the fuel electrode channel 10 is used to export the generated pure hydrogen gas, and the fuel electrode channel 10 has fuel electrode gas inlet (not shown) and fuel electrode gas outlet (not shown).

[0042] Specifically, the first electrolyte 2 is located between the oxygen electrode 1 and the fuel electrode 3; the second electrolyte 6 is located between the oxygen pump anode 5 and the oxygen pump cathode 7.

[0043] Specifically, the second electrolyte 6 is an oxygen ion conductor solid. The proton-conducting solid oxide electrolytic cell 9 has a plate structure.

[0044] Specifically, the oxygen pump anode 5 and the oxygen electrode 1 share a common conductive current collector, and the oxygen pump cathode 7 is connected to the negative terminal of an external power source.

[0045] In this embodiment, the oxygen pump is used to reduce the oxygen in the oxygen electrode channel 8 under the drive of an external electric field, eliminate oxygen vacancies and form lattice oxygen ions. The lattice oxygen ions migrate to the oxygen pump anode 5 via the second electrolyte 6. The lattice oxygen ions are oxidized to release oxygen and regenerate oxygen vacancies. The oxygen is discharged into the oxygen pump channel 4.

[0046] When power is supplied to the proton-conducting solid oxide electrolytic cell 9, water vapor in the oxygen electrode channel 8 is electrolyzed to produce oxygen in the oxygen electrode channel 8 and pure hydrogen in the fuel electrode channel 10. At the same time, a DC voltage is applied to the oxygen pump, and the oxygen pump cathode 7 reduces the oxygen in the oxygen electrode channel 8, eliminates oxygen vacancies and forms lattice oxygen ions. The lattice oxygen ions migrate to the oxygen pump anode 5 via the second electrolyte 6. The lattice oxygen ions are oxidized to release oxygen and regenerate oxygen vacancies. The oxygen is discharged from the oxygen pump channel 4, thereby actively reducing the oxygen partial pressure in the oxygen electrode channel 8.

[0047] When applying the equipment, after obtaining the proton-conducting solid oxide electrolyzer and the oxygen pump, they are installed in the appropriate and well-sealed equipment according to the structural sequence of oxygen pump channel 4, oxygen pump anode 5, second electrolyte 6, oxygen pump cathode 7, oxygen electrode channel 8, proton-conducting solid oxide electrolyzer 9, and fuel electrode channel 10; wherein the oxygen electrode side is connected to the oxygen electrode channel, and the fuel electrode side is connected to the fuel electrode channel.

[0048] The proton-conducting solid oxide electrolyzer and the oxygen pump share the same oxygen electrode channel 8. Air carrying water vapor is introduced into the oxygen electrode channel 8, while nitrogen is introduced into the oxygen pump channel 4. The oxygen pump actively extracts oxygen from the oxygen electrode channel 8 and discharges it into the oxygen pump channel 4, thereby reducing the oxygen partial pressure in the oxygen electrode channel 8 and improving the performance of the proton-conducting solid oxide electrolyzer.

[0049] The following section will verify the model of the proton-conducting solid oxide electrolyzer system in the embodiments. Theoretical models will be performed for the oxygen pump anode, the second electrolyte, the oxygen pump cathode, the oxygen electrode flow channel, and the proton-conducting solid oxide electrolyzer.

[0050] The model simulated the operation of an oxygen pump and a proton-conducting solid oxide electrolyzer at 873 K and an operating pressure of 1 atmosphere. The oxygen electrode channel was set to be purged with a gas composition of 90% air (containing 21% oxygen and 79% nitrogen) and 10% water vapor, while the oxygen pump channel was set to be purged with a gas composition of 0.01% oxygen and 99.99% nitrogen.

[0051] Establish a system-one, proton-conducting solid oxide electrolyzer without an integrated oxygen pump.

[0052] Meanwhile, a System II is established, which includes an oxygen electrode channel with a length of 0.1m, a width of 0.1m, and a height of 0.01m; a second electrolyte with a length of 0.1m, a width of 0.1m, and a thickness of 0.005m; and a proton-conducting solid oxidation electrolysis cell with a length of 0.1m and a width of 0.1m, which serves as a control group.

[0053] Figure 3 The relationship between the electrolysis voltage and external current density under operating conditions is shown for System 1 and System 2. Figure 3 As can be seen, System 2, which integrates an oxygen pump, has a significantly lower electrolysis voltage than System 1 under the same external current density. This lower electrolysis voltage helps improve the operational stability of the proton-conducting solid oxide electrolyzer and reduce its energy consumption.

[0054] Figure 4 The oxygen partial pressure in the oxygen electrode flow channel of System 1 and System 2 under operating conditions is shown. Figure 4 This indicates that during operation, the oxygen partial pressure at the oxygen electrode channel of System 2, which integrates the oxygen pump, is much lower than that of System 1.

[0055] Figure 5 The Faraday efficiency of System 1 and System 2 under operating conditions is demonstrated. From Figure 5 It can be seen that, under the same operating conditions, System 2, which integrates an oxygen pump, has a Faraday efficiency that is approximately 4% to 14% higher than that of System 1. This result demonstrates that integrating an oxygen pump can effectively improve the Faraday efficiency of the proton-conducting solid oxide electrolyzer.

[0056] Although embodiments of this application have been shown and described above, the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be conceived without inventive effort should be covered within the scope of protection of this invention. Unless expressly stated otherwise, no element, action or instruction used herein should be construed as critical or necessary.

Claims

1. A highly efficient hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump, characterized in that, include: Proton-conducting solid oxide electrolyzer and oxygen pump; The proton-conducting solid oxide electrolytic cell includes an oxygen electrode, a first electrolyte, a fuel electrode, a fuel electrode channel, and an oxygen electrode channel. The oxygen pump includes an oxygen pump anode, a second electrolyte, an oxygen pump cathode, and an oxygen pump flow channel; The oxygen electrode flow channel is adjacent to the oxygen pump flow channel and is separated by the second electrolyte, the oxygen pump anode and the oxygen pump cathode. The oxygen electrode channel is used to introduce air containing water vapor; The oxygen pump channel is used to introduce nitrogen or inert gas; The fuel electrode channel is used to export the generated pure hydrogen gas; When power is supplied to the proton-conducting solid oxide electrolyzer, water vapor in the oxygen electrode channel is electrolyzed to generate oxygen in the oxygen electrode channel and pure hydrogen in the fuel electrode channel. When a DC voltage is applied to the oxygen pump, the oxygen pump cathode reduces the oxygen in the oxygen electrode channel, eliminates oxygen vacancies and forms lattice oxygen ions. The lattice oxygen ions migrate to the oxygen pump anode via the second electrolyte. The lattice oxygen ions are oxidized to release oxygen and regenerate oxygen vacancies. The released oxygen is discharged into the oxygen pump channel to reduce the oxygen partial pressure in the oxygen electrode channel.

2. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 1, characterized in that, The first electrolyte is located between the oxygen electrode and the fuel electrode.

3. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 2, characterized in that, The second electrolyte is located between the oxygen pump anode and the oxygen pump cathode.

4. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 3, characterized in that, The second electrolyte is an oxygen ion conductor solid.

5. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 1, characterized in that, The proton-conducting solid oxide electrolytic cell has a plate structure.

6. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 1, characterized in that, The oxygen electrode flow channel is provided with an oxygen electrode gas inlet and an oxygen electrode gas outlet on both sides.

7. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 1, characterized in that, The oxygen pump has a nitrogen inlet and a nitrogen outlet on both sides of the flow channel.

8. The high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 1, characterized in that, The fuel electrode flow channel has a fuel electrode gas inlet and a fuel electrode gas outlet.

9. A high-efficiency hydrogen production system integrating a proton-conducting solid oxide electrolyzer and an oxygen pump according to claim 8, characterized in that, Also includes: Conductive current collector and external power supply; The oxygen pump anode and oxygen electrode share the same conductive current collector, and the oxygen pump cathode is connected to the negative terminal of an external power source.

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