Electrolytic hydrogen production plant and method for operating same

Abstract

The invention provides an electrolytic hydrogen production device and an operation method thereof. The electrolytic hydrogen production device comprises a proton exchange membrane flow battery, a first proton exchange membrane electrolytic bath, a second proton exchange membrane electrolytic bath, a positive electrode electrolyte water tank, a negative electrode electrolyte water tank, a methanol storage tank and a control switching device, the proton exchange membrane flow battery is used for performing reversible redox reaction on the positive electrode electrolyte and the negative electrode electrolyte to realize charging and discharging; an anode chamber of the first proton exchange membrane electrolytic cell is used for carrying out oxidation reaction on methanol to obtain methyl formate and hydrogen ions; a cathode chamber of the second proton exchange membrane electrolytic cell is used for reducing hydrogen ions to obtain hydrogen; the positive electrode electrolyte water tank is used for carrying out oxidation-reduction reaction on the positive electrode electrolyte and realizing circulation; the negative electrode electrolyte water tank is used for carrying out oxidation-reduction reaction on the negative electrode electrolyte and realizing circulation; the control switching device is used for controlling the operation mode of the device. The device is high in safety and volatility absorption capacity and large in energy storage capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic hydrogen production, and in particular to an electrolytic hydrogen production device and an operation method thereof. Background Art

[0002] Hydrogen energy storage is one of the important ways to store energy for a long time. However, the cathode hydrogen evolution reaction (HER) and the anode oxygen evolution reaction (OER) of traditional water electrolysis occur simultaneously in one reactor. When the power supply fluctuates, hydrogen and oxygen crossover easily occurs, thus causing safety hazards. In addition, OER is the rate-limiting reaction of water electrolysis, and its energy consumption is high, resulting in poor process economy.

[0003] In traditional energy storage systems, hydrogen storage and electrochemical storage are two independent modules, which have poor ability to absorb fluctuating electricity. In addition, traditional electrochemical energy storage has low capacity and is difficult to expand.

[0004] Therefore, there is an urgent need to develop a hydrogen production process with high safety, high volatility absorption capability and large energy storage capacity. Summary of the invention

[0005] The main purpose of the present invention is to provide an electrolytic hydrogen production device and an operating method thereof, so as to solve the problems in the prior art of poor safety and volatility absorption capacity of the hydrogen production process, as well as low electrochemical energy storage capacity and difficulty in expansion.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an electrolytic hydrogen production device, which comprises: a proton exchange membrane flow battery, a first proton exchange membrane electrolyzer, a second proton exchange membrane electrolyzer, a positive electrolyte water tank, a negative electrolyte water tank, a methanol storage tank and a control switching device, the proton exchange membrane flow battery is electrically connected to a first power supply, the proton exchange membrane flow battery has a positive electrode chamber and a negative electrode chamber, the positive electrode chamber is connected to a positive electrode electrolyte source, the negative electrode chamber is connected to a negative electrode electrolyte source, the proton exchange membrane flow battery is used to perform a reversible redox reaction of the positive electrode electrolyte and the negative electrode electrolyte to achieve charging and discharging; the first proton exchange membrane electrolyzer is electrically connected to the second power supply, the first proton exchange membrane electrolyzer has a first anode chamber and a first cathode chamber, the first anode chamber is used to perform an oxidation reaction on methanol to obtain methyl formate and hydrogen ions; the second proton exchange membrane electrolyzer is electrically connected to a third power supply, the second proton exchange membrane electrolyzer has a first cathode chamber and a first cathode chamber, the first anode chamber is used to perform an oxidation reaction on methanol to obtain methyl formate and hydrogen ions; There are two anode chambers and a second cathode chamber, and the second cathode chamber is used to reduce hydrogen ions to obtain hydrogen; the positive electrode electrolyte water tank is bidirectionally connected with the positive electrode chamber and the first cathode chamber respectively, and the positive electrode electrolyte water tank is used to store the positive electrode electrolyte and carry out oxidation-reduction reaction of the positive electrode electrolyte between the positive electrode chamber and the first cathode chamber and realize circulation; the negative electrode electrolyte water tank is bidirectionally connected with the negative electrode chamber and the second anode chamber respectively, and the negative electrode electrolyte water tank is used to store the negative electrode electrolyte and carry out oxidation-reduction reaction of the negative electrode electrolyte between the negative electrode chamber and the second anode chamber and realize circulation; the methanol storage tank is bidirectionally connected with the first anode chamber of the first proton exchange membrane electrolyzer, and the methanol storage tank is used to provide methanol to the first anode chamber; the control switching device is electrically connected with the first power supply, the second power supply and the third power supply respectively, and the control switching device is used to adjust the working state of the first power supply, the second power supply and the third power supply and the power supply form, so as to control the operation mode of the electrolytic hydrogen production device.

[0007] Further, the load of the proton exchange membrane flow battery is provided by the first proton exchange membrane electrolyzer and / or the second proton exchange membrane electrolyzer, and / or the power of the proton exchange membrane flow battery is 10-100 kW.

[0008] Furthermore, the proton exchange membrane flow battery is a vanadium flow battery or an iron-chromium flow battery; when the proton exchange membrane flow battery is a vanadium flow battery, the electrolyte in the positive electrode chamber is VO 2+ The electrolyte in the negative electrode compartment is V 3+ solution; the electrolyte in the first cathode chamber is the electrolyte VO in the positive electrode chamber 2+ The acid solution undergoes oxidation reaction to generate VO2 + Acid solution, VO2 + The acid solution undergoes a reduction reaction in the first cathode chamber to generate VO 2+ The electrolyte in the second anode chamber is the electrolyte V in the negative electrode chamber. 3+The solution undergoes a reduction reaction to generate V 2+ Solution, V 2+ The solution undergoes oxidation reaction in the second anode chamber to generate V 3+ Solution.

[0009] Furthermore, the positive electrode electrolyte in the positive electrode electrolyte water tank is a sulfuric acid solution containing pentavalent vanadium ions and tetravalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 0.1-1.5 mol / L, and the molar concentration of sulfate ions in the sulfuric acid solution is 0.1-2.5 mol / L; and / or, the negative electrode electrolyte in the negative electrode electrolyte water tank is a sulfuric acid solution containing trivalent vanadium ions and divalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 0.1-1.5 mol / L, and the molar concentration of sulfate ions in the sulfuric acid solution is 0.1-2.5 mol / L.

[0010] Furthermore, a circulation pump is provided on the connecting pipeline between the methanol storage tank and the first anode chamber for the circulation of methanol between the methanol storage tank and the first anode chamber; and / or, a circulation pump is independently provided on the connecting pipeline between the positive electrode electrolyte water tank and the positive electrode chamber, and on the connecting pipeline between the positive electrode electrolyte water tank and the first cathode chamber, for the circulation of the positive electrode electrolyte between the positive electrode chamber and the first cathode chamber; and / or, a circulation pump is independently provided on the connecting pipeline between the negative electrode electrolyte water tank and the negative electrode chamber, and on the connecting pipeline between the negative electrode electrolyte water tank and the second anode chamber, for the circulation of the negative electrode electrolyte between the negative electrode chamber and the second anode chamber.

[0011] According to another aspect of the present invention, there is provided an operating method for producing hydrogen using the above-mentioned electrolytic hydrogen production device, the operating method comprising: during the charging process of the proton exchange membrane flow battery, the positive electrode electrolyte undergoes a first oxidation reaction at the positive electrode of the proton exchange membrane flow battery to obtain first oxidized ions; the first oxidized ions undergo a first reduction reaction at the first cathode of the first proton exchange membrane electrolyzer to obtain first reduced ions; methanol undergoes a second oxidation reaction at the first anode of the first proton exchange membrane electrolyzer to obtain methyl formate and hydrogen ions; the negative electrode electrolyte undergoes a second reduction reaction at the negative electrode of the proton exchange membrane flow battery to obtain second reduced ions; the second reduced ions undergo a third oxidation reaction at the second anode of the second proton exchange membrane electrolyzer to obtain third oxidized ions; the hydrogen ions undergo a third oxidation reaction at the first anode of the second proton exchange membrane electrolyzer to obtain third oxidized ions; The second cathode of the two proton exchange membrane electrolyzers undergoes a third reduction reaction to obtain hydrogen; during the discharge process of the proton exchange membrane flow battery, the positive electrode of the proton exchange membrane flow battery undergoes a first reduction reaction, and the negative electrode of the proton exchange membrane flow battery undergoes a first oxidation reaction; the operating state of the first power supply, the second power supply, and the third power supply and the power supply form are switched by controlling the switching device to control the operation mode of the electrolytic hydrogen production device; wherein, the negative electrode electrolyte circulates between the negative electrode of the proton exchange membrane flow battery and the second anode of the second proton exchange membrane electrolyzer; the positive electrode electrolyte circulates between the positive electrode of the proton exchange membrane flow battery and the first cathode of the first proton exchange membrane electrolyzer; and methanol circulates between the first anode of the first proton exchange membrane electrolyzer and the methanol storage tank.

[0012] Further, the proton exchange membrane flow battery is a vanadium flow battery or an iron-chromium flow battery; when the proton exchange membrane flow battery is a vanadium flow battery, the operation mode of the electrolytic hydrogen production device is a non-time-sharing operation mode, and the first power supply, the second power supply, and the third power supply are controlled to independently provide power for photovoltaics, and the current values ​​of the first power supply, the second power supply, and the third power supply are the same and independently 10 to 1000A, wherein the reaction equations of the first oxidation reaction, the first reduction reaction, the second oxidation reaction, the second reduction reaction, the third oxidation reaction, and the third reduction reaction are as follows:

[0013] VO 2+ (aq)+H2O(l)→VO2 + (aq)+2H + (aq)+e - (I)

[0014] VO2 + (aq)+2H + (aq)+e - →VO 2+ (aq)+H2O(l) (II)

[0015] 2CH3OH(l)→HCOOCH3(l)+4H+ (aq)+4e - (III)

[0016] V 3+ (aq)+e - →V 2+ (aq) (IV)

[0017] V 2+ (aq)→V 3+ (aq)+e - (V)

[0018] 2H + (aq)+2e - →H2(g) (VI).

[0019] Furthermore, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the second power supply work, and the first power supply and the second power supply are controlled to independently provide power for the photovoltaic power generation. The current values ​​of the first power supply and the second power supply are the same and independently 10 to 1000A. The H + The molar concentration of is 0.5-6.0 mol / L, and (I)-(IV) reactions occur during the daytime operation; at night, only the third power source works, and the third power source is controlled to provide valley electricity, and the current value of the third power source is 10-1000A; H in the negative electrode electrolyte + The molar concentration is 0.2-5.0 mol / L, and (V)-(VI) reactions occur during nighttime operation.

[0020] Furthermore, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the third power supply work. The first power supply and the third power supply are controlled to independently provide power for the photovoltaic power plant. The current values ​​of the first power supply and the third power supply are the same and independently 10 to 1000A. The H + The molar concentration of is 0.1-4.0 mol / L, and reactions (I), (IV)-(VI) occur during the daytime operation; at night, only the second power supply works, and the second power supply is controlled to provide power for valley electricity, and the current value of the second power supply is 10-1000A; H in the negative electrode electrolyte + The molar concentration is 0.2-5.0 mol / L, and reactions (II) and (III) occur during nighttime operation.

[0021] Furthermore, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the second power supply and the third power supply work. The second power supply and the third power supply are controlled to independently provide power to the photovoltaic power plant. The current values ​​of the second power supply and the third power supply are the same and independently 10 to 1000A. The H +The molar concentration of is 0.1-4.0 mol / L, and reactions (II), (III), (V), and (VI) occur during the daytime operation; at night, only the first power source works, and the first power source is controlled to provide power for valley electricity, and the current value of the first power source is 10-1000A; H in the negative electrode electrolyte + The molar concentration is 0.2-5.0 mol / L, and reactions (I) and (IV) occur during nighttime operation.

[0022] Furthermore, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power source works and controls the first power source to provide power for photovoltaic power generation. The current value of the first power source is 10 to 1000A. + The molar concentration of the second power supply is 0.5-6.0 mol / L, and the reactions (I) and (IV) occur during the daytime operation; at night, only the second power supply and the third power supply work, and the second power supply and the third power supply are controlled to independently provide power for valley electricity, and the current values ​​of the second power supply and the third power supply are the same and independently 10-1000A, and the H in the negative electrolyte + The molar concentration is 0.1-4.0 mol / L, and reactions (II), (III), (V) and (VI) occur during nighttime operation.

[0023] Applying the technical solution of the present invention, the present application integrates the flow battery with the decoupled methanol electrolysis hydrogen production process to obtain the above-mentioned electrolysis hydrogen production device. Specifically, the proton exchange membrane flow battery, the positive electrode electrolyte water tank and the negative electrode electrolyte water tank form a liquid circulation system, and the charging and discharging of the proton exchange membrane flow battery are realized by the reversible redox reaction of the electrolyte. On the basis of the above process, during the charging process of the proton exchange membrane flow battery, the high-valent ions generated by its positive electrode are reduced at the cathode of the first proton exchange membrane electrolyzer, and at the same time, methanol undergoes an oxidation reaction in the first anode chamber of the first proton exchange membrane electrolyzer to produce methyl formate and hydrogen ions, and the low-valent ions generated by the negative electrode of the proton exchange membrane flow battery undergo an oxidation reaction in the second anode chamber of the second proton exchange membrane electrolyzer, and at the same time, the hydrogen ions undergo a reduction reaction in the second cathode chamber of the second proton exchange membrane electrolyzer to produce hydrogen. The electrolytic hydrogen production device of the present invention also has the following advantages: 1) The present invention utilizes the reversible redox reaction in the liquid current system to realize the decoupled electrolysis of methanol to produce hydrogen. The electrolysis reaction can be divided into two independent steps in time and space. The oxidation reaction and the reduction reaction can occur in sequence in different chambers with the help of liquid redox media, thereby simultaneously producing hydrogen and organic oxidation product methyl formate in different regions and times. At the same time, the use of organic methanol oxidation reaction to replace the anode oxygen evolution reaction can significantly reduce energy consumption, thereby achieving higher economic value and safety. 2) Especially in the application of fluctuating renewable energy power electrolysis hydrogen production, the use of proton exchange membrane flow battery as an intermediate power source for water electrolysis hydrogen production can effectively utilize the advantages of the strong time response characteristics of electrochemical cells, thereby improving the process stability of hydrogen production. 3) The present invention utilizes two water electrolysis half reactions to couple with the positive and negative electrode reactions of the proton exchange membrane flow battery, respectively, so as to simultaneously convert the electrical energy to be consumed into battery chemical energy and hydrogen energy, which can solve the problem of low capacity and difficult expansion of traditional electrochemical energy storage. 4) The electrolytic hydrogen production device of the present invention is an integrated device, and the size of the equipment can be reduced by improving the degree of integration. The interrelated reversible battery reaction and hydrogen production reaction improve the responsiveness of the molecular reaction time scale. Compared with the control between two independent systems, the electrolytic hydrogen production device of the present invention has a stronger ability to absorb fluctuating electricity. 5) The operating state and power supply form of each of the above-mentioned power sources are adjusted by the above-mentioned control switching device to control the operation mode of the electrolytic hydrogen production device, which can maximize the price advantage of electricity at different times, thereby further improving the economy of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1A schematic diagram of the electrolytic hydrogen production device in Example 1 of the present application is shown.

[0026] The above drawings include the following reference numerals:

[0027] 1. Proton exchange membrane flow battery; 2. First proton exchange membrane electrolyzer; 3. Second proton exchange membrane electrolyzer; 4. Positive electrode electrolyte water tank; 5. Negative electrode electrolyte water tank; 6. Methanol storage tank; 7. Circulation pump A; 8. Circulation pump B; 9. Circulation pump C; 10. Circulation pump D; 11. Circulation pump E. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] As analyzed in the background technology of this application, the hydrogen production process in the prior art has the problems of poor safety and volatility absorption capacity, as well as low electrochemical energy storage capacity and difficulty in expansion. In order to solve the above problems, this application provides an electrolytic hydrogen production device and its operation method.

[0030] In a typical embodiment of the present application, a hydrogen production device by electrolysis is provided, such as Figure 1As shown, the electrolytic hydrogen production device includes: a proton exchange membrane flow battery 1, a first proton exchange membrane electrolyzer 2, a second proton exchange membrane electrolyzer 3, a positive electrode electrolyte water tank 4, a negative electrode electrolyte water tank 5, a methanol storage tank 6 and a control switching device, the proton exchange membrane flow battery 1 is electrically connected to the first power supply, the proton exchange membrane flow battery 1 has a positive electrode chamber and a negative electrode chamber, the positive electrode chamber is connected to the positive electrode electrolyte source, the negative electrode chamber is connected to the negative electrode electrolyte source, the proton exchange membrane flow battery 1 is used to perform a reversible redox reaction of the positive electrode electrolyte and the negative electrode electrolyte to achieve charging and discharging; the first proton exchange membrane electrolyzer 2 is electrically connected to the second power supply, the first proton exchange membrane electrolyzer 2 has a first anode chamber and a first cathode chamber, the first anode chamber is used to perform an oxidation reaction on methanol to obtain methyl formate and hydrogen ions; the second proton exchange membrane electrolyzer 3 is electrically connected to the third power supply, the second proton exchange membrane electrolyzer 3 has a second anode chamber and a second cathode chamber, The second cathode chamber is used to reduce hydrogen ions to obtain hydrogen; the positive electrode electrolyte water tank 4 is bidirectionally connected with the positive electrode chamber and the first cathode chamber respectively, and the positive electrode electrolyte water tank 4 is used to store the positive electrode electrolyte and carry out oxidation-reduction reaction of the positive electrode electrolyte between the positive electrode chamber and the first cathode chamber and realize circulation; the negative electrode electrolyte water tank 5 is bidirectionally connected with the negative electrode chamber and the second anode chamber respectively, and the negative electrode electrolyte water tank 5 is used to store the negative electrode electrolyte and carry out oxidation-reduction reaction of the negative electrode electrolyte between the negative electrode chamber and the second anode chamber and realize circulation; the methanol storage tank 6 is bidirectionally connected with the first anode chamber of the first proton exchange membrane electrolyzer 2, and the methanol storage tank 6 is used to provide methanol to the first anode chamber; the control switching device is electrically connected with the first power supply, the second power supply, and the third power supply respectively, and the control switching device is used to adjust the working state of the first power supply, the second power supply, and the third power supply and the power supply form, so as to control the operation mode of the electrolytic hydrogen production device.

[0031] The present application integrates a flow battery with a decoupled methanol electrolysis hydrogen production process to obtain the above-mentioned electrolysis hydrogen production device. Specifically, the proton exchange membrane flow battery 1, the positive electrode electrolyte water tank 4 and the negative electrode electrolyte water tank 5 form a liquid circulation system, and the charging and discharging of the proton exchange membrane flow battery 1 are realized by the reversible redox reaction of the electrolyte. On the basis of the above process, during the charging process of the proton exchange membrane flow battery 1, the high-valent ions generated by the positive electrode are reduced at the cathode of the first proton exchange membrane electrolyzer 2, and at the same time, methanol undergoes an oxidation reaction in the first anode chamber of the first proton exchange membrane electrolyzer 2 to produce methyl formate and hydrogen ions, and the low-valent ions generated by the negative electrode of the proton exchange membrane flow battery 1 undergo an oxidation reaction in the second anode chamber of the second proton exchange membrane electrolyzer 3, and at the same time, the hydrogen ions undergo a reduction reaction in the second cathode chamber of the second proton exchange membrane electrolyzer 3 to produce hydrogen. The electrolytic hydrogen production device of the present invention also has the following advantages: 1) The present invention utilizes the reversible redox reaction in the liquid current system to realize the decoupled electrolysis of methanol to produce hydrogen. The electrolysis reaction can be divided into two independent steps in time and space. The oxidation reaction and the reduction reaction can occur in sequence in different chambers with the help of liquid redox media, thereby simultaneously producing hydrogen and organic oxidation product methyl formate in different regions and times. At the same time, the use of organic methanol oxidation reaction to replace the anode oxygen evolution reaction can significantly reduce energy consumption, thereby achieving higher economic value and safety. 2) Especially in the application of fluctuating renewable energy power electrolysis hydrogen production, the proton exchange membrane liquid flow battery 1 is used as an intermediate power source to electrolyze water to produce hydrogen, which can effectively utilize the advantages of the strong time response characteristics of the electrochemical battery, thereby improving the process stability of hydrogen production. 3) The present invention utilizes two water electrolysis half reactions to couple with the positive and negative electrode reactions of the proton exchange membrane liquid flow battery 1, respectively, so as to simultaneously convert the electrical energy to be consumed into battery chemical energy and hydrogen energy, which can solve the problem of low capacity and difficult expansion of traditional electrochemical energy storage. 4) The electrolytic hydrogen production device of the present invention is an integrated device, and the size of the equipment can be reduced by improving the degree of integration. The interrelated reversible battery reaction and hydrogen production reaction improve the responsiveness of the molecular reaction time scale. Compared with the control between two independent systems, the electrolytic hydrogen production device of the present invention has a stronger ability to absorb fluctuating electricity. 5) The operating state and power supply form of each of the above-mentioned power sources are adjusted by the above-mentioned control switching device to control the operation mode of the electrolytic hydrogen production device, which can maximize the price advantage of electricity at different times, thereby further improving the economy of the process.

[0032] In one embodiment of the present application, the load of the proton exchange membrane flow battery 1 is provided by the first proton exchange membrane electrolyzer 2 and / or the second proton exchange membrane electrolyzer 3, and / or the power of the proton exchange membrane flow battery 1 is 10 to 100 kW.

[0033] Preferably, the first proton exchange membrane electrolyzer 2 and the second proton exchange membrane electrolyzer 3 provide a load to the proton exchange membrane flow battery 1 and control the power of the proton exchange membrane flow battery 1 within the above range, which helps to realize the circulation of the reversible redox pair in the battery system through the two half reactions in the first proton exchange membrane electrolyzer 2 and the second proton exchange membrane electrolyzer 3, and simultaneously use the battery chemical energy for the production of hydrogen and methyl formate. Preferably, the material of the first proton exchange membrane electrolyzer 2 and the second proton exchange membrane electrolyzer 3 is titanium or a metal material with a titanium coating on the surface.

[0034] In one embodiment of the present application, the proton exchange membrane flow battery 1 is a vanadium flow battery or an iron-chromium flow battery; when the proton exchange membrane flow battery 1 is a vanadium flow battery, the electrolyte in the positive electrode chamber is VO 2+ The electrolyte in the negative electrode compartment is V 3+ solution; the electrolyte in the first cathode chamber is the electrolyte VO in the positive electrode chamber 2+ The acid solution undergoes oxidation reaction to generate VO2 + Acid solution, VO2 + The acid solution undergoes a reduction reaction in the first cathode chamber to generate VO 2+ The electrolyte in the second anode chamber is the electrolyte V in the negative electrode chamber. 3+ The solution undergoes a reduction reaction to generate V 2+ Solution, V 2+ The solution undergoes oxidation reaction in the second anode chamber to generate V 3+ Solution.

[0035] Compared with the method of directly connecting the power supply to the electrolyzer, it is preferred to introduce the above-mentioned type of proton exchange membrane flow battery 1 into the electrolytic hydrogen production device, which helps to achieve the decoupling of hydrogen production and methyl formate production through the above-mentioned reaction, while avoiding the process of gas-liquid separation in different electrolyzers, thereby further simplifying the process of the present application.

[0036] In one embodiment of the present application, the positive electrode electrolyte in the above-mentioned positive electrode electrolyte water tank 4 is a sulfuric acid solution containing pentavalent vanadium ions and tetravalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 0.1-1.5 mol / L, and the molar concentration of sulfate ions in the sulfuric acid solution is 0.1-2.5 mol / L; and / or, the negative electrode electrolyte in the negative electrode electrolyte water tank 5 is a sulfuric acid solution containing trivalent vanadium ions and divalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 0.1-1.5 mol / L, and the molar concentration of sulfate ions in the sulfuric acid solution is 0.1-2.5 mol / L.

[0037] It is preferred to control the types and molar concentrations of the positive electrolyte in the positive electrolyte tank 4 and the negative electrolyte in the negative electrolyte tank 5 within the above range, which helps to achieve charging and discharging of the proton exchange membrane flow battery 1 through the reversible redox reaction of the above positive and negative electrolytes.

[0038] In one embodiment of the present application, a circulation pump is provided on the connecting pipeline between the methanol storage tank 6 and the first anode chamber, which is used for the circulation of methanol between the methanol storage tank 6 and the first anode chamber; and / or, a circulation pump is independently provided on the connecting pipeline between the positive electrode electrolyte water tank 4 and the positive electrode chamber, and on the connecting pipeline between the positive electrode electrolyte water tank 4 and the first cathode chamber, for the circulation of the positive electrode electrolyte between the positive electrode chamber and the first cathode chamber; and / or, a circulation pump is independently provided on the connecting pipeline between the negative electrode electrolyte water tank 5 and the negative electrode chamber, and on the connecting pipeline between the negative electrode electrolyte water tank 5 and the second anode chamber, for the circulation of the negative electrode electrolyte between the negative electrode chamber and the second anode chamber.

[0039] The above-mentioned circulation pump is preferably provided to help circulate the electrolyte, thereby ensuring the normal operation of the device.

[0040] In another typical embodiment of the present application, a method for operating hydrogen produced by the above-mentioned electrolytic hydrogen production device is provided, and the operating method includes: during the charging process of the proton exchange membrane flow battery 1, the positive electrode electrolyte undergoes a first oxidation reaction at the positive electrode of the proton exchange membrane flow battery 1 to obtain a first oxidized ion; the first oxidized ion undergoes a first reduction reaction at the first cathode of the first proton exchange membrane electrolyzer 2 to obtain a first reduced ion; methanol undergoes a second oxidation reaction at the first anode of the first proton exchange membrane electrolyzer 2 to obtain methyl formate and hydrogen ions; the negative electrode electrolyte undergoes a second reduction reaction at the negative electrode of the proton exchange membrane flow battery 1 to obtain a second reduced ion; the second reduced ion undergoes a third oxidation reaction at the second anode of the second proton exchange membrane electrolyzer 3 to obtain a third oxidized ion; the hydrogen ion The second cathode of the second proton exchange membrane electrolyzer 3 undergoes a third reduction reaction to obtain hydrogen; during the discharge process of the proton exchange membrane flow battery 1, the positive electrode of the proton exchange membrane flow battery 1 undergoes a first reduction reaction, and the negative electrode of the proton exchange membrane flow battery 1 undergoes a first oxidation reaction; the operating state of the first power supply, the second power supply, and the third power supply and the power supply form are switched by controlling the switching device to control the operation mode of the electrolytic hydrogen production device; wherein, the negative electrode electrolyte circulates between the negative electrode of the proton exchange membrane flow battery 1 and the second anode of the second proton exchange membrane electrolyzer 3; the positive electrode electrolyte circulates between the positive electrode of the proton exchange membrane flow battery 1 and the first cathode of the first proton exchange membrane electrolyzer 2; and methanol circulates between the first anode of the first proton exchange membrane electrolyzer 2 and the methanol storage tank 6.

[0041] The above-mentioned electrolytic hydrogen production device is used to produce hydrogen through the above-mentioned operation method, and the charging and discharging of the proton exchange membrane flow battery 1 can be realized through the reversible redox reaction of the electrolyte, thereby realizing the decoupled electrolysis of methanol to produce hydrogen. The electrolysis reaction can be divided into two independent steps in time and space. The oxidation reaction and the reduction reaction can occur in sequence in different chambers with the help of liquid redox media, thereby simultaneously producing hydrogen and organic oxidation product methyl formate in different regions and times. At the same time, the use of organic methanol oxidation reaction instead of anode oxygen evolution reaction can significantly reduce energy consumption, thereby achieving higher economic value and safety. The above-mentioned operation mode can maximize the price advantage of electricity at different times, thereby further improving the economy of the process. Among them, the separation method of methanol and methyl formate is vacuum distillation, and the generated hydrogen enters the three-tower drying device for purification without deoxygenation treatment.

[0042] In one embodiment of the present application, the proton exchange membrane flow battery 1 is a vanadium flow battery or an iron-chromium flow battery; when the proton exchange membrane flow battery 1 is a vanadium flow battery, the operation mode of the electrolytic hydrogen production device is a non-time-sharing operation mode, and the first power supply, the second power supply, and the third power supply are controlled to independently provide power for photovoltaics, and the current values ​​of the first power supply, the second power supply, and the third power supply are the same and independently 10 to 1000A, wherein the reaction equations of the first oxidation reaction, the first reduction reaction, the second oxidation reaction, the second reduction reaction, the third oxidation reaction, and the third reduction reaction are as follows:

[0043] VO 2+ (aq)+H2O(l)→VO2 + (aq)+2H + (aq)+e - (I)

[0044] VO2 + (aq)+2H + (aq)+e - →VO 2+ (aq)+H2O(l) (II)

[0045] 2CH3OH(l)→HCOOCH3(l)+4H + (aq)+4e - (III)

[0046] V 3+ (aq)+e - →V 2+ (aq) (IV)

[0047] V 2+ (aq)→V 3+ (aq)+e - (V)

[0048] 2H + (aq)+2e - →H2(g) (VI).

[0049] It is preferred to control the operation mode of the electrolytic hydrogen production device to a non-time-sharing operation mode, and use photovoltaic power to provide power to the first power supply, the second power supply, and the third power supply and control their respective current values ​​within the above-mentioned range, which helps to make full use of photovoltaic power to carry out methanol electrolysis half-reaction to produce methyl formate, thereby reducing operating energy consumption.

[0050] In one embodiment of the present application, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the second power supply work, and the first power supply and the second power supply are controlled to independently provide power for photovoltaic power. The current values ​​of the first power supply and the second power supply are the same and independently 10 to 1000A. The H in the negative electrode electrolyte + The molar concentration of is 0.5-6.0 mol / L, and (I)-(IV) reactions occur during the daytime operation; at night, only the third power source works, and the third power source is controlled to provide valley electricity, and the current value of the third power source is 10-1000A; H in the negative electrode electrolyte + The molar concentration is 0.2-5.0 mol / L, and (V)-(VI) reactions occur during nighttime operation.

[0051] The above-mentioned time-sharing operation mode is preferably adopted, which is helpful to arrange production according to the demand of downstream products, new energy electricity prices and valley electricity prices, thereby helping to use fluctuating photovoltaic power for the methanol electrolysis half-reaction to produce methyl formate during the day, and use stable and low-cost valley electricity for the water electrolysis half-reaction to produce hydrogen at night, thereby helping to maintain stable hydrogen production, which is beneficial to the stability of the subsequent hydrogen compression section.

[0052] In one embodiment of the present application, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the third power supply work, and the first power supply and the third power supply are controlled to independently provide power for photovoltaic power. The current values ​​of the first power supply and the third power supply are the same and independently 10 to 1000A. The H in the negative electrode electrolyte + The molar concentration of is 0.1-4.0 mol / L, and reactions (I), (IV)-(VI) occur during the daytime operation; at night, only the second power supply works, and the second power supply is controlled to provide power for valley electricity, and the current value of the second power supply is 10-1000A; H in the negative electrode electrolyte + The molar concentration is 0.2-5.0 mol / L, and reactions (II) and (III) occur during nighttime operation.

[0053] The above-mentioned time-sharing operation mode is preferably adopted, which is helpful to arrange production according to the demand of downstream products, new energy electricity prices and valley electricity prices, thereby helping to use fluctuating photovoltaic power for water electrolysis half-reaction to produce hydrogen during the day, and use stable and low-cost valley electricity for electrolysis of methanol to methyl formate half-reaction at night, thereby helping to maintain a stable output of methyl formate, and further facilitating a stable supply of downstream chemical products.

[0054] In one embodiment of the present application, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the second power supply and the third power supply work, and the second power supply and the third power supply are controlled to independently provide power for photovoltaic power. The current values ​​of the second power supply and the third power supply are the same and independently 10 to 1000A. The H in the negative electrode electrolyte + The molar concentration of is 0.1-4.0 mol / L, and reactions (II), (III), (V), and (VI) occur during the daytime operation; at night, only the first power source works, and the first power source is controlled to provide power for valley electricity, and the current value of the first power source is 10-1000A; H in the negative electrode electrolyte + The molar concentration is 0.2-5.0 mol / L, and reactions (I) and (IV) occur during nighttime operation.

[0055] The above-mentioned time-sharing operation mode is preferably adopted, which is helpful to arrange production according to the demand of downstream products, new energy electricity prices and valley electricity prices, thereby helping to use fluctuating photovoltaic power for the methanol electrolysis half-reaction to produce methyl formate and the water electrolysis half-reaction to produce hydrogen during the day, and realize renewable energy storage through the conversion of electrical energy into chemicals. At the same time, the operation of the proton exchange membrane flow battery 1 at night can realize power peak regulation while restoring the electrolyte components.

[0056] In one embodiment of the present application, the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power source works, and the first power source is controlled to provide photovoltaic power. The current value of the first power source is 10 to 1000A, and the H in the negative electrode electrolyte is + The molar concentration of the second power supply is 0.5-6.0 mol / L, and the reactions (I) and (IV) occur during the daytime operation; at night, only the second power supply and the third power supply work, and the second power supply and the third power supply are controlled to independently provide power for valley electricity, and the current values ​​of the second power supply and the third power supply are the same and independently 10-1000A, and the H in the negative electrolyte + The molar concentration is 0.1-4.0 mol / L, and reactions (II), (III), (V) and (VI) occur during nighttime operation.

[0057] The above-mentioned time-sharing operation mode is preferably adopted, which is helpful to arrange production according to the demand of downstream products, new energy electricity prices and valley electricity prices, thereby helping to absorb the fluctuating photovoltaic power and restore the electrolyte components of the proton exchange membrane flow battery 1 during the day, and using stable and low-cost valley electricity at night to carry out the water electrolysis hydrogen production half-reaction and methanol electrolysis half-reaction to produce methyl formate, thereby helping to maintain a stable output of hydrogen and methyl formate, and further facilitating the realization of a stable downstream chemical product supply and power peak regulation.

[0058] The beneficial effects of the present application will be further illustrated below in conjunction with embodiments.

[0059] Example 1

[0060] Use Figure 1 The electrolytic hydrogen production device shown in the figure is used to electrolyze methanol to produce hydrogen. When the proton exchange membrane flow battery 1 is a vanadium flow battery, the positive electrode electrolyte is a sulfuric acid solution containing pentavalent vanadium ions and tetravalent vanadium ions. The total molar concentration of vanadium ions in the sulfuric acid solution is 1 mol / L, and the molar concentration of sulfate ions is 2 mol / L. During the charging process of the proton exchange membrane flow battery 1, the vanadium ions containing VO 2+ The positive electrode electrolyte of the sulfuric acid solution undergoes a first oxidation reaction (I) at the positive electrode of the proton exchange membrane flow battery 1, and the first oxidant ion VO2 + The concentration of the first oxidizing ion VO2 + The first reduction reaction (II) is carried out at the first cathode of the first proton exchange membrane electrolyzer 2, and the first reduced ion VO 2+ The concentration of anhydrous methanol is subjected to a second oxidation reaction (III) at the first anode of the first proton exchange membrane electrolyzer 2 to obtain methyl formate, and the hydrogen ion concentration at the cathode side of the first proton exchange membrane electrolyzer 2 is increased; the negative electrode electrolyte is a sulfuric acid solution containing trivalent vanadium ions and divalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 1 mol / L, the molar concentration of sulfate ions in the sulfuric acid solution is 2 mol / L, and the V 2+ and V 3+ The negative electrode electrolyte of the sulfuric acid solution undergoes a second reduction reaction (IV) at the negative electrode of the proton exchange membrane flow battery 1, and the second reduced ion V 2+ The concentration increases; the second reducing ion V 2+ The third oxidation reaction (V) is carried out at the second anode of the second proton exchange membrane electrolyzer 3, and the third oxidized ion V 3+The concentration increases; hydrogen ions undergo a third reduction reaction (VI) at the second cathode of the second proton exchange membrane electrolyzer 3 to obtain hydrogen; during the discharge process of the proton exchange membrane flow battery 1, the hydrogen production module does not work, the positive electrode of the proton exchange membrane flow battery 1 undergoes a first reduction reaction (I), and the negative electrode of the proton exchange membrane flow battery 1 undergoes a first oxidation reaction (II); wherein, the negative electrode electrolyte circulates between the negative electrode of the proton exchange membrane flow battery 1 and the second anode of the second proton exchange membrane electrolyzer 3 through a circulation pump D10; the positive electrode electrolyte circulates between the positive electrode of the proton exchange membrane flow battery 1 and the first cathode of the first proton exchange membrane electrolyzer 2 through a circulation pump A7; methanol circulates between the first anode of the first proton exchange membrane electrolyzer 2 and the methanol storage tank 6 through a circulation pump E11; a circulation pump B8 is provided on the connecting pipeline between the positive electrode electrolyte water tank 4 and the positive electrode chamber, and a circulation pump C9 is provided on the connecting pipeline between the negative electrode electrolyte water tank 5 and the negative electrode chamber.

[0061] The operation mode of the electrolytic hydrogen production device is a non-time-sharing operation mode. The switching device is controlled to control the first power supply, the second power supply, and the third power supply to provide power from photovoltaics. The current values ​​of the first power supply, the second power supply, and the third power supply are the same and are 500A. The circulation pumps A to E are all turned on. The first proton exchange membrane electrolyzer 2 and the second proton exchange membrane electrolyzer 3 are the loads of the proton exchange membrane flow battery 1, with a power of 50kW. The proton exchange membrane flow battery 1 is charged and discharged at the same time. At the same time, the anode of the first proton exchange membrane electrolyzer 2 generates methyl formate, and the synchronously generated H + It passes through the proton exchange membrane in the first proton exchange membrane electrolyzer 2, the proton exchange membrane flow battery 1, and the second proton exchange membrane electrolyzer 3 in sequence, and produces hydrogen on the cathode side of the second proton exchange membrane electrolyzer 3. In this process, the components in the positive and negative electrolyte water tanks do not change, the overall reaction is reaction (VII), and the reversible reaction (VIII) is carried out simultaneously. Among them, the reaction equations of the first oxidation reaction, the first reduction reaction, the second oxidation reaction, the second reduction reaction, the third oxidation reaction, the third reduction reaction, the overall reaction, and the reversible reaction are as follows:

[0062] VO 2+ (aq)+H2O(l)→VO2 + (aq)+2H + (aq)+e - (I)

[0063] VO2 + (aq)+2H + (aq)+e - →VO 2+ (aq)+H2O(l) (II)

[0064] 2CH3OH(l)→HCOOCH3(l)+4H+ (aq)+4e - (III)

[0065] V 3+ (aq)+e - →V 2+ (aq) (IV)

[0066] V 2+ (aq)→V 3+ (aq)+e - (V)

[0067] 2H + (aq)+2e - →H2(g) (VI)

[0068] 2CH3OH(l)→HCOOCH3(l)+2H2(g) (VII)

[0069]

[0070] Example 2

[0071] The difference from Example 1 is that the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the second power supply work. Both the first power supply and the second power supply provide electricity from photovoltaics. The current values ​​of the first power supply and the second power supply are the same and are both 500A. The circulation pumps A7, B8 and E11 are turned on. The first proton exchange membrane electrolyzer 2 is the load of the proton exchange membrane flow battery 1, with a power of 50kW. The proton exchange membrane flow battery 1 is charged and discharged on the positive side at the same time. At the same time, the anode of the first proton exchange membrane electrolyzer 2 generates methyl formate, and the synchronously generated H + The H2O2 passes through the first proton exchange membrane electrolyzer 2 and the proton exchange membrane in the proton exchange membrane flow battery 1 in turn, and enters the negative electrode electrolyte water tank 5. In this process, the components in the positive electrode electrolyte water tank 4 do not change, while the H2O2 in the negative electrode electrolyte water tank 5 + The molar concentration of is increased to 5 mol / L, and the system is shut down after the photovoltaic power is interrupted. During the daytime operation, reactions (I) to (IV) occur.

[0072] At night, only the third power supply works, and the third power supply provides valley electricity. The current value of the third power supply is 500A; the circulation pump C9 and the circulation pump D10 are turned on, and the second proton exchange membrane electrolyzer 3 is the load of the proton exchange membrane flow battery 1, with a power of 50kW, and the negative electrode side of the proton exchange membrane flow battery 1 is discharged. At the same time, the H in the negative electrode electrolyte tank 5 + The H2O2 in the negative electrode electrolyte water tank 5 passes through the proton exchange membrane in the second proton exchange membrane electrolyzer 3, and hydrogen is produced on the cathode side of the second proton exchange membrane electrolyzer 3.+ The molar concentration is reduced to 4 mol / L, and reactions (V) to (VI) occur during night operation.

[0073] On a day-long scale, the overall reaction is reaction (VII), and the reversible reaction (VIII) is carried out simultaneously. The components in the positive electrode electrolyte water tank 4 and the negative electrode electrolyte water tank 5 do not change.

[0074] Example 3

[0075] The difference from Example 1 is that the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the third power supply work. Both the first power supply and the third power supply provide electricity from photovoltaics. The current values ​​of the first power supply and the third power supply are the same and are both 500A. The circulation pump C9 and the circulation pump D10 are turned on. The second proton exchange membrane electrolyzer 3 is the load of the proton exchange membrane flow battery 1 with a power of 50kW. The proton exchange membrane flow battery 1 is charged and discharged on the negative electrode side at the same time. At the same time, the H generated in the positive electrode electrolyte water tank 4 + The H2O2 passes through the proton exchange membrane in the proton exchange membrane flow battery 1 and the second proton exchange membrane electrolyzer 3 in sequence, and the cathode of the second proton exchange membrane electrolyzer 3 generates hydrogen. In this process, the components in the negative electrode electrolyte water tank 5 do not change, while the H2O2 in the positive electrode electrolyte water tank 4 does not change. + The molar concentration of the ions is reduced to 3 mol / L, and the system is shut down after the photovoltaic power is interrupted. During the daytime operation, reactions (I), (IV) to (VI) occur.

[0076] At night, only the second power supply is working, and the second power supply provides power for valley electricity. The current value of the second power supply is 500A; the circulation pump A7, the circulation pump B8, and the circulation pump E11 are turned on, and the first proton exchange membrane electrolyzer 2 is the load of the proton exchange membrane flow battery 1, with a power of 50kW, and the positive side of the proton exchange membrane flow battery 1 is discharged. At the same time, the anode of the first proton exchange membrane electrolyzer 2 generates methyl formate, and the synchronously generated H + The H in the positive electrode electrolyte water tank 4 passes through the proton exchange membrane of the first proton exchange membrane electrolyzer 2 and enters the positive electrode electrolyte water tank 4. + The molar concentration was increased to 4 mol / L, and reactions (II) and (III) occurred during night operation.

[0077] On a day-long scale, the overall reaction is reaction (VII), and the reversible reaction (VIII) is carried out simultaneously. The components in the positive electrode electrolyte water tank 4 and the negative electrode electrolyte water tank 5 do not change.

[0078] Example 4

[0079] The difference from Example 1 is that the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the second power supply and the third power supply work. Both the second power supply and the third power supply provide electricity from photovoltaic power. The current values ​​of the second power supply and the third power supply are the same and are both 500A. The circulation pump A7, the circulation pump D10 and the circulation pump E11 are turned on. The proton exchange membrane flow battery 1 discharges on the positive and negative sides at the same time. Hydrogen is generated at the cathode of the second proton exchange membrane electrolyzer 3, and methyl formate is generated on the anode side of the first proton exchange membrane electrolyzer 2. In this process, H in the negative electrode electrolyte water tank 5 + The molar concentration of H in the positive electrolyte water tank 4 is reduced to 3 mol / L. + The molar concentration of is increased to 5 mol / L, and the system is shut down after the photovoltaic power is interrupted. During the daytime operation, reactions (II), (III), (V), and (VI) occur.

[0080] At night, only the first power supply is working, and the first power supply provides power for valley electricity. The current value of the first power supply is 500A; the circulation pump B8 and the circulation pump C9 are turned on. The proton exchange membrane flow battery 1 is charged. During this process, the H in the negative electrode electrolyte tank 5 + The molar concentration of H in the positive electrolyte water tank 4 is increased to 4 mol / L. + The molar concentration of is reduced to 4 mol / L, and reactions (I) and (IV) occur during night operation.

[0081] On a day-long scale, the overall reaction is reaction (VII), and the reversible reaction (VIII) is carried out simultaneously. The components in the positive electrode electrolyte water tank 4 and the negative electrode electrolyte water tank 5 do not change.

[0082] Example 5

[0083] The difference from Example 1 is that the operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power source works. The first power source provides power for photovoltaics. The current value of the first power source is 500A. The circulating pump B8 and the circulating pump C9 are turned on. The proton exchange membrane flow battery 1 is charged. In this process, the H in the negative electrode electrolyte water tank 5 is + The molar concentration of H in the positive electrolyte water tank 4 is increased to 5 mol / L. + The molar concentration of (I) and (IV) is reduced to 3 mol / L, and the system is shut down after the photovoltaic power is interrupted.

[0084] At night, only the second power supply and the third power supply work. Both the second power supply and the third power supply provide valley electricity. The current values ​​of the second power supply and the third power supply are the same and are both 500A. The circulation pump A7, the circulation pump D10 and the circulation pump E11 are turned on. The proton exchange membrane flow battery 1 discharges on the positive and negative sides at the same time. Hydrogen is generated at the cathode of the second proton exchange membrane electrolyzer 3, and methyl formate is generated on the anode side of the first proton exchange membrane electrolyzer 2. In this process, H in the negative electrode electrolyte water tank 5 + The molar concentration of H in the positive electrolyte tank 4 is reduced to 4 mol / L. + The molar concentration of is increased to 4 mol / L, and reactions (II), (III), (V) and (VI) occur during night operation.

[0085] On a day-long scale, the overall reaction is reaction (VII), and the reversible reaction (VIII) is carried out simultaneously. The components in the positive electrode electrolyte water tank 4 and the negative electrode electrolyte water tank 5 do not change.

[0086] Comparative Example 1

[0087] The difference from Example 1 is that the electrolytic hydrogen production device does not have a proton exchange membrane flow battery 1, and methyl formate and hydrogen are finally obtained.

[0088] Test method:

[0089] Methyl formate yield = mass of methyl formate produced during continuous operation for 24 hours / mass of methanol input into the system.

[0090] The masses of methyl formate and methanol are measured by electronic scales, and the output of hydrogen is measured by a flow meter.

[0091] The results of hydrogen yield and methyl formate yield in the above examples and comparative examples are shown in Table 1.

[0092] Table 1

[0093]

[0094] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0095] The present application integrates a flow battery with a decoupled methanol electrolysis hydrogen production process to obtain the above-mentioned electrolysis hydrogen production device. Specifically, the proton exchange membrane flow battery, the positive electrode electrolyte water tank and the negative electrode electrolyte water tank form a liquid circulation system, and the charging and discharging of the proton exchange membrane flow battery is realized by the reversible redox reaction of the electrolyte. On the basis of the above process, during the charging process of the proton exchange membrane flow battery, the high-valent ions generated by its positive electrode are reduced at the cathode of the first proton exchange membrane electrolyzer, and at the same time, methanol undergoes an oxidation reaction in the first anode chamber of the first proton exchange membrane electrolyzer to produce methyl formate and hydrogen ions, and the low-valent ions generated by the negative electrode of the proton exchange membrane flow battery undergo an oxidation reaction in the second anode chamber of the second proton exchange membrane electrolyzer, and at the same time, the hydrogen ions undergo a reduction reaction in the second cathode chamber of the second proton exchange membrane electrolyzer to produce hydrogen. The electrolytic hydrogen production device of the present invention also has the following advantages: 1) The present invention utilizes the reversible redox reaction in the liquid current system to realize the decoupled electrolysis of methanol to produce hydrogen. The electrolysis reaction can be divided into two independent steps in time and space. The oxidation reaction and the reduction reaction can occur in sequence in different chambers with the help of liquid redox media, thereby simultaneously producing hydrogen and organic oxidation product methyl formate in different regions and times. At the same time, the use of organic methanol oxidation reaction to replace the anode oxygen evolution reaction can significantly reduce energy consumption, thereby achieving higher economic value and safety. 2) Especially in the application of fluctuating renewable energy power electrolysis hydrogen production, the use of proton exchange membrane flow battery as an intermediate power source for water electrolysis hydrogen production can effectively utilize the advantages of the strong time response characteristics of electrochemical cells, thereby improving the process stability of hydrogen production. 3) The present invention utilizes two water electrolysis half reactions to couple with the positive and negative electrode reactions of the proton exchange membrane flow battery, respectively, so as to simultaneously convert the electrical energy to be consumed into battery chemical energy and hydrogen energy, which can solve the problem of low capacity and difficult expansion of traditional electrochemical energy storage. 4) The electrolytic hydrogen production device of the present invention is an integrated device, and the size of the equipment can be reduced by improving the degree of integration. The interrelated reversible battery reaction and hydrogen production reaction improve the responsiveness of the molecular reaction time scale. Compared with the control between two independent systems, the electrolytic hydrogen production device of the present invention has a stronger ability to absorb fluctuating electricity. 5) The operating state and power supply form of each of the above-mentioned power sources are adjusted by the above-mentioned control switching device to control the operation mode of the electrolytic hydrogen production device, which can maximize the price advantage of electricity at different times, thereby further improving the economy of the process.

[0096] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydrogen production device by electrolysis, characterized in that: The electrolytic hydrogen production device comprises: A proton exchange membrane flow battery (1) is electrically connected to a first power source, the proton exchange membrane flow battery (1) comprising a positive electrode chamber and a negative electrode chamber, the positive electrode chamber being connected to a positive electrode electrolyte source, the negative electrode chamber being connected to a negative electrode electrolyte source, the proton exchange membrane flow battery (1) being used for performing a reversible redox reaction between the positive electrode electrolyte and the negative electrode electrolyte to achieve charging and discharging; A first proton exchange membrane electrolyzer (2) is electrically connected to a second power supply, wherein the first proton exchange membrane electrolyzer (2) comprises a first anode chamber and a first cathode chamber, wherein the first anode chamber is used to perform an oxidation reaction on methanol to obtain methyl formate and hydrogen ions; a second proton exchange membrane electrolyzer (3) electrically connected to a third power source, wherein the second proton exchange membrane electrolyzer (3) comprises a second anode chamber and a second cathode chamber, wherein the second cathode chamber is used to perform a reduction reaction on the hydrogen ions to obtain hydrogen; A positive electrode electrolyte water tank (4), the positive electrode electrolyte water tank (4) is bidirectionally connected to the positive electrode chamber and the first cathode chamber respectively, and the positive electrode electrolyte water tank (4) is used to store the positive electrode electrolyte and carry out an oxidation-reduction reaction of the positive electrode electrolyte between the positive electrode chamber and the first cathode chamber to realize circulation; A negative electrode electrolyte water tank (5), the negative electrode electrolyte water tank (5) is bidirectionally connected to the negative electrode chamber and the second anode chamber respectively, and the negative electrode electrolyte water tank (5) is used to store the negative electrode electrolyte and carry out an oxidation-reduction reaction of the negative electrode electrolyte between the negative electrode chamber and the second anode chamber to realize circulation; a methanol storage tank (6), the methanol storage tank (6) being bidirectionally connected to the first anode chamber of the first proton exchange membrane electrolyzer (2), and the methanol storage tank (6) being used to provide methanol to the first anode chamber; A control switching device, wherein the control switching device is electrically connected to the first power supply, the second power supply, and the third power supply respectively, and the control switching device is used to adjust the working status and power supply form of the first power supply, the second power supply, and the third power supply, so as to control the operation mode of the electrolysis hydrogen production device.

2. The electrolytic hydrogen production device according to claim 1, characterized in that: The load of the proton exchange membrane flow battery (1) is provided by the first proton exchange membrane electrolyzer (2) and / or the second proton exchange membrane electrolyzer (3), and / or the power of the proton exchange membrane flow battery (1) is 10 to 100 kW.

3. The electrolytic hydrogen production device according to claim 1 or 2, characterized in that: The proton exchange membrane flow battery (1) is a vanadium flow battery or an iron-chromium flow battery; when the proton exchange membrane flow battery (1) is the vanadium flow battery, the electrolyte in the positive electrode chamber is VO 2+ The electrolyte in the negative electrode compartment is V 3+ Solution; The electrolyte in the first cathode chamber is the electrolyte VO in the cathode chamber. 2+ The acid solution undergoes oxidation reaction to generate VO2 + The acid solution, the VO2 + The acid solution undergoes a reduction reaction in the first cathode chamber to generate VO 2+ Acid solution; The electrolyte in the second anode chamber is the electrolyte V in the cathode chamber. 3+ The solution undergoes a reduction reaction to generate V 2+ solution, the V 2+ The solution undergoes an oxidation reaction in the second anode chamber to generate V 3+ Solution.

4. The electrolytic hydrogen production device according to claim 3, characterized in that: The positive electrode electrolyte in the positive electrode electrolyte water tank (4) is a sulfuric acid solution containing pentavalent vanadium ions and tetravalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 0.1 to 1.5 mol / L, and the molar concentration of sulfate ions in the sulfuric acid solution is 0.1 to 2.5 mol / L; And / or, the negative electrode electrolyte in the negative electrode electrolyte water tank (5) is a sulfuric acid solution containing trivalent vanadium ions and divalent vanadium ions, the total molar concentration of vanadium ions in the sulfuric acid solution is 0.1 to 1.5 mol / L, and the molar concentration of sulfate ions in the sulfuric acid solution is 0.1 to 2.5 mol / L.

5. The electrolytic hydrogen production device according to any one of claims 1 to 4, characterized in that: A circulation pump is provided on the connecting pipeline between the methanol storage tank (6) and the first anode chamber, for circulating the methanol between the methanol storage tank (6) and the first anode chamber; and / or, a circulation pump is independently provided on the connecting pipeline between the positive electrode electrolyte water tank (4) and the positive electrode chamber, and on the connecting pipeline between the positive electrode electrolyte water tank (4) and the first cathode chamber, for circulating the positive electrode electrolyte between the positive electrode chamber and the first cathode chamber; and / or, a circulation pump is independently provided on the connecting pipeline between the negative electrode electrolyte water tank (5) and the negative electrode chamber, and on the connecting pipeline between the negative electrode electrolyte water tank (5) and the second anode chamber, for circulating the negative electrode electrolyte between the negative electrode chamber and the second anode chamber.

6. An operating method for producing hydrogen using the electrolytic hydrogen production device according to any one of claims 1 to 5, characterized in that: The operation method comprises: During the charging process of the proton exchange membrane flow battery (1), the positive electrode electrolyte undergoes a first oxidation reaction at the positive electrode of the proton exchange membrane flow battery (1) to obtain a first oxidized ion; The first oxidized ions undergo a first reduction reaction at a first cathode of a first proton exchange membrane electrolyzer (2) to obtain first reduced ions; Methanol undergoes a second oxidation reaction at the first anode of the first proton exchange membrane electrolyzer (2) to obtain methyl formate and hydrogen ions; The negative electrode electrolyte undergoes a second reduction reaction at the negative electrode of the proton exchange membrane flow battery (1) to obtain second reduced ions; The second reduced ions undergo a third oxidation reaction at the second anode of the second proton exchange membrane electrolyzer (3) to obtain third oxidized ions; The hydrogen ions undergo a third reduction reaction at the second cathode of the second proton exchange membrane electrolyzer (3) to obtain hydrogen; During the discharge process of the proton exchange membrane flow battery (1), the positive electrode of the proton exchange membrane flow battery (1) undergoes the first reduction reaction, and the negative electrode of the proton exchange membrane flow battery (1) undergoes the first oxidation reaction; The operating mode of the electrolytic hydrogen production device is controlled by switching the working state of the first power supply, the second power supply, and the third power supply and the power supply form through the control switching device; The negative electrode electrolyte circulates between the negative electrode of the proton exchange membrane flow battery (1) and the second anode of the second proton exchange membrane electrolyzer (3); The positive electrode electrolyte circulates between the positive electrode of the proton exchange membrane flow battery (1) and the first cathode of the first proton exchange membrane electrolyzer (2); The methanol circulates between the first anode of the first proton exchange membrane electrolyzer (2) and the methanol storage tank (6).

7. The operating method according to claim 6, characterized in that: The proton exchange membrane flow battery (1) is a vanadium flow battery or an iron-chromium flow battery; when the proton exchange membrane flow battery (1) is the vanadium flow battery, the operation mode of the electrolytic hydrogen production device is a non-time-sharing operation mode, and the first power supply, the second power supply, and the third power supply are controlled to independently provide photovoltaic power, and the current values ​​of the first power supply, the second power supply, and the third power supply are the same and independently 10 to 1000A, wherein the reaction equations of the first oxidation reaction, the first reduction reaction, the second oxidation reaction, the second reduction reaction, the third oxidation reaction, and the third reduction reaction are as follows: VO 2+ (aq)+H2O(l)→VO2 + (aq)+2H + (aq)+e - (I) VO2 + (aq)+2H + (aq)+e - →VO 2+ (aq)+H2O(l)(II) 2CH3OH(l)→HCOOCH3(l)+4H + (aq)+4e - (III) V 3+ (aq)+e - →V 2+ (aq)(IV) V 2+ (aq)→V 3+ (aq)+e - (V) 2H + (aq)+2e - →H2(g)(VI)。 8. The operating method according to claim 6, characterized in that: The operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the second power supply work. The first power supply and the second power supply are controlled to independently provide power for photovoltaic power generation. The current values ​​of the first power supply and the second power supply are the same and independently 10 to 1000A. The H in the negative electrode electrolyte + The molar concentration is 0.5-6.0 mol / L, and reactions (I)-(IV) occur during daytime operation; At night, only the third power source works, and the third power source is controlled to provide valley power. The current value of the third power source is 10-1000A. + The molar concentration is 0.2-5.0 mol / L, and (V)-(VI) reactions occur during nighttime operation.

9. The operating method according to claim 6, characterized in that: The operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply and the third power supply work. The first power supply and the third power supply are controlled to independently provide power for photovoltaic power generation. The current values ​​of the first power supply and the third power supply are the same and independently 10 to 1000A. The H in the negative electrode electrolyte + The molar concentration is 0.1 to 4.0 mol / L, and reactions (I) (I), (IV) to (VI) occur during daytime operation; At night, only the second power supply works, and the second power supply is controlled to provide valley power. The current value of the second power supply is 10-1000A. + The molar concentration is 0.2-5.0 mol / L, and reactions (II) and (III) occur during nighttime operation.

10. The operating method according to claim 6, characterized in that: The operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the second power supply and the third power supply work. The second power supply and the third power supply are controlled to independently provide power for photovoltaic power generation. The current values ​​of the second power supply and the third power supply are the same and independently 10 to 1000A. The H in the negative electrode electrolyte + The molar concentration is 0.1-4.0 mol / L, and reactions (II), (III), (V), and (VI) occur during daytime operation; At night, only the first power source works, and the first power source is controlled to provide valley power. The current value of the first power source is 10-1000A. + The molar concentration is 0.2-5.0 mol / L, and reactions (I) and (IV) occur during nighttime operation.

11. The operating method according to claim 6, characterized in that: The operation mode of the electrolytic hydrogen production device is a time-sharing operation mode. During the day, only the first power supply works and controls the first power supply to provide photovoltaic power. The current value of the first power supply is 10-1000A. The H + The molar concentration is 0.5-6.0 mol / L, and reactions (I) and (IV) occur during daytime operation; At night, only the second power supply and the third power supply work, and the second power supply and the third power supply are controlled to independently provide power for valley electricity, and the current values ​​of the second power supply and the third power supply are the same and independently 10 to 1000A, and the H in the negative electrode electrolyte is + The molar concentration is 0.1-4.0 mol / L, and reactions (II), (III), (V) and (VI) occur during nighttime operation.

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