Process for producing hydrogen from water in bipolar electrolytic cell
By using a bipolar electrolyzer for hydrogen production from water, the problems of varying electrical load and regulating hydrogen and oxygen pressure in electrolyzer-based hydrogen production have been solved. This has enabled stable liquid levels and balanced concentrations in the hydrogen-oxygen separator, ensuring the stability and zero emissions of industrial production.
Patent Information
- Application Number
- CN202411450833.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2025-01-07
AI Technical Summary
Existing water-to-hydrogen processes include electrolysis, which suffers from large variations in power load, difficulty in regulating hydrogen and oxygen pressure, and large fluctuations in downstream pressure. In alkaline water-to-hydrogen processes, the hydrogen and oxygen tank level control is risky and there is an explosion risk.
The process employs a bipolar electrolyzer for hydrogen production, including a hydrogen gas holder, two hydrogen production systems, a gas-liquid separation system, and a water and alkali replenishment circulation system. Interlocking technology enables rapid current increases and decreases, ensuring stable liquid levels and concentration in the hydrogen-oxygen separator. U-shaped bends and nitrogen-filling pipelines are installed to ensure safety.
It enables rapid adjustment of current during the production process, stable liquid level in the hydrogen-oxygen separator, and balanced concentration, ensuring stable industrial production and achieving zero emissions.
Smart Images
Figure CN119265588A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a bipolar electrolyzer water hydrogen production process, belonging to the technical field of water electrolysis hydrogen production. Background Art
[0002] Hydrogen production by water electrolysis is one of the most widely used and mature methods. The process of producing hydrogen with water as raw material is the reverse process of hydrogen and oxygen burning to produce water. Therefore, as long as a certain form of certain energy is provided, water can be decomposed. The efficiency of providing electric energy to decompose water to produce hydrogen is generally 75-85%. The process is simple and pollution-free, but it consumes a lot of electricity, so its application is subject to certain restrictions. Using the peak and valley difference of the power grid to electrolyze water to produce hydrogen is also unique as a means of energy storage. my country is rich in hydropower resources, and the use of hydropower to generate electricity and electrolyze water to produce hydrogen has its development prospects. Solar energy is inexhaustible, and the method of using photoelectric hydrogen production is called solar hydrogen energy system, which has been experimentally studied abroad. With the improvement of solar cell conversion efficiency, the reduction of cost and the extension of service life, its prospect for hydrogen production is immeasurable. At the same time, solar energy, wind energy and ocean energy can also be used to produce hydrogen through electricity and use hydrogen as an intermediate energy carrier to regulate and store conversion energy, making the energy supply to users more flexible and convenient. When the power supply system is at a low point, the surplus electricity can also be used to electrolyze water to produce hydrogen, achieving the purpose of energy storage. There are hundreds of water electrolysis hydrogen production devices of various sizes in my country, but they are all small-scale electrolysis hydrogen production equipment, and their purpose is to produce hydrogen feedstock rather than as energy. With the gradual expansion of hydrogen energy applications, water electrolysis hydrogen production methods will surely develop.
[0003] At present, water hydrogen production processes mainly include electrolytic water hydrogen production and alkaline water hydrogen production. The two processes mainly have the following problems: 1. When using the electrolytic cell water hydrogen production process, the power load changes greatly, and the hydrogen and oxygen pressures at the cell outlet are difficult to adjust, and the pressure after the valve fluctuates greatly; 2. When using alkaline water to produce hydrogen, the liquid level in the hydrogen and oxygen tank is mainly controlled by connecting the bottom pipeline of the hydrogen and oxygen separator, relying on the control of the oxygen side pressure and the hydrogen and oxygen pressure difference in cascade control. During the electrolysis process, as the electrolysis time progresses, the concentration difference in the hydrogen and oxygen tank will increase, and once the liquid level control valve is not good, the liquid level of the hydrogen and oxygen separator will be out of adjustment, there will be a risk of explosion. Summary of the invention
[0004] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of the prior art, a bipolar electrolyzer water hydrogen production process is provided to achieve rapid increase and decrease of current, stable liquid level of hydrogen and oxygen separator, and balanced concentration during the production process, to achieve industrialized stable production and achieve zero emissions.
[0005] The technical solution adopted by the present invention to solve the above problems is: a bipolar electrolyzer water hydrogen production process, including a hydrogen gas cabinet and two hydrogen production systems, and the two hydrogen production systems are connected to the hydrogen gas cabinet; The hydrogen production system comprises a hydrogen preparation system, a gas-liquid separation system, a water-adding alkali supplementation circulation system, and a power supply and distribution and control system. The hydrogen preparation system is connected to the gas-liquid separation system, and the gas-liquid separation system is connected to the water-adding alkali supplementation circulation system. The power supply and distribution and control system are respectively connected to the hydrogen preparation system, the gas-liquid separation system, and the water-adding alkali supplementation circulation system by electric wires. Two hydrogen preparation systems and two gas-liquid separation systems are each provided, and the two hydrogen preparation systems correspond to the two gas-liquid separation systems one by one. The hydrogen preparation system comprises an electrolytic cell, in which water is decomposed into hydrogen and oxygen under the action of electric current; The gas-liquid separation system comprises a hydrogen gas-liquid cooling separator and an oxygen gas-liquid cooling separator, and the electrolyzer of the hydrogen preparation system is connected to the hydrogen gas-liquid cooling separator and the oxygen gas-liquid cooling separator respectively; The water-adding alkali-supplementing circulation system comprises a circulating alkali tank and a pure water storage tank, wherein the pure water storage tank is connected to the circulating alkali tank; The circulating alkali tank is connected with two elbows, which correspond to the hydrogen gas-liquid cooling separator and the oxygen gas-liquid cooling separator respectively. The liquid outlet of the hydrogen gas-liquid cooling separator and the liquid outlet of the oxygen gas-liquid cooling separator are both connected to the circulating alkali tank through the elbows. The gas outlet of the hydrogen gas-liquid cooling separator is connected to the hydrogen main pipe, and the gas outlet of the oxygen gas-liquid cooling separator is connected to the oxygen main pipe. The electrolyzer is connected to the circulating alkali tank, and the electrolyte circulates among the electrolyzer, the hydrogen gas-liquid cooling separator and the oxygen gas-liquid cooling separator through a circulating pump. The circulating alkali tank is connected to the hydrogen gas cabinet through a water mist collector.
[0006] Preferably, the bent pipe is U-shaped.
[0007] Preferably, the height of the curved pipe is 4 m.
[0008] Preferably, the working process of the power supply and distribution and control system is as follows: Set up the interlocking process. When the interlocking input signal is abnormal, in order to ensure that the hydrogen production device is shut down and effectively handled, the specific operations are as follows; 1.1. Low flow alarm interlock of cathode and anode electrolyte in the electrolytic cell. If the electrolyte flow rate LL exceeds 5 seconds, the system will stop. 1.2. The rectifier fault cannot be restored, the system stops and enters the automatic processing program; 1.3. If the hydrogen-oxygen pressure difference at the electrolyzer outlet exceeds the HH value for 5 seconds, the system will stop; 1.4. If the oxygen and hydrogen content at the outlet of the electrolyzer exceeds the HH value for 3 seconds, the system will be shut down; 1.5. The total voltage of the electrolytic cell and the voltage of each unit are monitored online. If the HH and LL are abnormal for more than 5 seconds, the system will stop; As a preferred option, after parking, the system interlocks automatically and the following are the output signals: 2.1. The cathode liquid water supply valve is cut off, the flow rate is 0, and the pump is frequency-controlled; 2.2. The valve from the hydrogen and oxygen pipeline to the user is automatically cut off, and the hydrogen and oxygen system can be filled with nitrogen for replacement and pressure maintenance; 2.3. The circulation flow of anode and cathode is automatically adjusted to maintain circulation and a certain temperature.
[0009] Preferably, a nitrogen filling valve is installed at the end of the anode and cathode main pipes of the electrolytic cell.
[0010] Preferably, the circulating alkali tank is provided with a nitrogen filling pipeline.
[0011] Preferably, the pure water storage tank transports the pure water to the circulating alkali tank via a water pump.
[0012] Preferably, the hydrogen produced by the hydrogen production system enters the hydrogen gas tank, and the hydrogen in the hydrogen gas tank is pressurized by a compressor and transported to customers.
[0013] Preferably, the gas phase pressure at the anode and cathode of the electrolytic cell is 20Kpa to 240Kpa.
[0014] Compared with the prior art, the advantages of the present invention are: The invention discloses a bipolar electrolyzer water hydrogen production process, which realizes rapid rise and fall of current, stable liquid level of hydrogen and oxygen separator, and balanced concentration during the production process, realizes industrialized stable production, and realizes zero emission. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a structural block diagram of a bipolar electrolyzer water hydrogen production process of the present invention; Figure 2 This is the structural block diagram of the connection between the hydrogen gas tank and the compressor; Figure 3 It is the structural block diagram of the hydrogen production system; Figure 4 It is a schematic diagram of the connection structure of the hydrogen preparation system, the gas-liquid separation system and the circulating alkali tank; Figure 5 It is a structural diagram of the power supply and distribution and control system.
[0016] Among them: hydrogen gas cabinet 1, compressor 2, electrolyzer 3, hydrogen gas-liquid cooling separator 4, oxygen gas-liquid cooling separator 5, circulating alkali tank 6, pure water storage tank 7, water pump 8, elbow 9, circulating pump 10, water mist collector 11. DETAILED DESCRIPTION
[0017] like Figure 1-5 As shown, a bipolar electrolyzer water hydrogen production process in this embodiment includes a hydrogen gas cabinet 1 and two hydrogen production systems. The two hydrogen production systems are connected to the hydrogen gas cabinet 1. The hydrogen produced by the hydrogen production system enters the hydrogen gas cabinet 1. The hydrogen in the hydrogen gas cabinet 1 is then pressurized by the compressor 2 and transported to the customer. The hydrogen production system comprises a hydrogen preparation system, a gas-liquid separation system, a water-adding alkali supplementation circulation system, and a power supply and distribution and control system. The hydrogen preparation system is connected to the gas-liquid separation system, and the gas-liquid separation system is connected to the water-adding alkali supplementation circulation system. The power supply and distribution and control system are respectively connected to the hydrogen preparation system, the gas-liquid separation system, and the water-adding alkali supplementation circulation system by electric wires. Two hydrogen preparation systems and two gas-liquid separation systems are each provided, and the two hydrogen preparation systems correspond to the two gas-liquid separation systems one by one. The hydrogen preparation system comprises an electrolytic cell 3, in which water in the electrolytic cell 3 is decomposed into hydrogen and oxygen under the action of electric current; The gas-liquid separation system comprises a hydrogen gas-liquid cooling separator 4 and an oxygen gas-liquid cooling separator 4, and the electrolyzer 3 of the hydrogen preparation system is connected to the hydrogen gas-liquid cooling separator 4 and the oxygen gas-liquid cooling separator 4 respectively; The water-adding alkali supplementation circulation system comprises a circulating alkali tank 6 and a pure water storage tank 7, wherein the pure water storage tank 7 is connected to the circulating alkali tank 6, and the pure water storage tank 7 transports pure water to the circulating alkali tank 6 through a water pump 8; The circulating alkali tank 6 is connected to two elbows 9, the elbows 9 are U-shaped, and the two elbows 9 correspond to the hydrogen gas-liquid cooling separator 4 and the oxygen gas-liquid cooling separator 4 respectively. The liquid outlet of the hydrogen gas-liquid cooling separator 4 and the liquid outlet of the oxygen gas-liquid cooling separator 4 are connected to the circulating alkali tank 6 through the U-shaped elbow 9, the gas outlet of the hydrogen gas-liquid cooling separator 4 is connected to the hydrogen main pipe, and the gas outlet of the oxygen gas-liquid cooling separator 4 is connected to the oxygen main pipe. The electrolyzer 3 is connected to the circulating alkali tank 6, and the circulating pump 10 is used to realize the circulation of electrolyte between the electrolyzer 3, the hydrogen gas-liquid cooling separator 4 and the oxygen gas-liquid cooling separator 4. The circulating alkali tank 6 is connected to the hydrogen gas cabinet 1 through the water mist collector 11; The electrolyte and gas outputted from the electrolyzer 3 enter the hydrogen gas-liquid cooling separator 4 and the oxygen gas-liquid cooling separator 4 respectively, and the hydrogen and electrolyte are separated by the hydrogen gas-liquid cooling separator 4, and the oxygen and electrolyte are separated by the oxygen gas-liquid cooling separator 4, and enter the hydrogen valve and the oxygen valve for pressure adjustment, the oxygen is directly discharged, the hydrogen enters the demisting gas, and then enters the hydrogen water seal, breaks through the water seal and enters the hydrogen gas cabinet 1, and finally the hydrogen in the hydrogen gas cabinet 1 is pressurized by the hydrogen compressor 2 and sent to different customers; The working process of the power supply and distribution and control system is as follows: Set up the interlocking process. When the interlocking input signal is abnormal, in order to ensure that the hydrogen production device is shut down and effectively handled, the specific operations are as follows; 1.1. Low electrolyte flow alarm interlock of anode and cathode in electrolytic cell 3. If the electrolyte flow rate LL exceeds 5 seconds, the system will stop. 1.2. The rectifier fault cannot be restored, the system stops and enters the automatic processing program; 1.3. The hydrogen-oxygen pressure difference at the outlet of electrolyzer 3 exceeds the HH value for 5 seconds, and the system stops; 1.4. The oxygen and hydrogen content at the outlet of electrolyzer 3 exceeds the HH value for 3 seconds, and the system stops; 1.5. The total voltage of electrolytic cell 3 and the voltage of each unit are monitored online. If the HH and LL are abnormal for more than 5 seconds, the system will be shut down; After parking, the system interlocks automatically and the following are the output signals: 2.1. The cathode liquid water supply valve is cut off, the flow rate is 0, and the pump is frequency-controlled; 2.2. The valve from the hydrogen and oxygen pipeline to the user is automatically cut off, and the hydrogen and oxygen system can be filled with nitrogen for replacement and pressure maintenance; 2.3. The circulation flow of anode and cathode is automatically adjusted to maintain circulation and a certain temperature; Here, by setting up the hydrogen gas cabinet 1, the whole production process can be automated without human intervention, and can be adjusted adaptively when the current fluctuates greatly. When the current changes, the gas production of the electrolyzer 3 is small, and the hydrogen valve and the oxygen valve are automatically closed slowly, and PdICZA1201 can be cascaded according to PIT1202 to maintain the hydrogen-oxygen pressure difference. When the electrolyzer 3 is running at low load, the amount of hydrogen entering the hydrogen gas cabinet 1 is small. At this time, the hydrogen compressor group 2 adjusts the reflux volume or frequency conversion control according to the liquid level of the hydrogen gas cabinet 1; The cathode and anode electrolytes from the electrolytic cell 3 enter the circulating alkali tank 6 from the U-shaped bend 9 after separation. The U-shaped bend 9 acts as a liquid seal. Generally, the gas phase pressure of the cathode and anode of the electrolytic cell 3 is 20Kpa-240Kpa. The height of the U-shaped bend 9 is about 4m, which ensures that the gas will not break through the liquid seal and enter the circulating alkali tank 6 during the separation process, and ensures that the cathode and anode circulating liquids can be mixed after entering the circulating alkali tank 6 to maintain the uniformity of the electrolyte concentration, thereby solving the problem of different concentrations of the cathode and anode liquids when they are circulated separately, and ultimately ensuring that the concentration difference between the cathode and anode sides of the cell is small and the voltage is stable; Secondly, the nitrogen filling valve at the end of the anode and cathode main pipes of electrolytic cell 3 can automatically fill nitrogen; In addition, the circulating alkali tank 6 is equipped with a nitrogen filling pipeline to ensure the safety of the circulating tank; In summary, the rapid rise and fall of current, the stability of the liquid level in the hydrogen and oxygen separator, and the balance of concentration can be achieved during the production process, thus achieving industrialized and stable production and zero emissions.
[0018] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.
Claims
1. A bipolar electrolyzer water hydrogen production process, characterized in that: It comprises a hydrogen gas cabinet (1) and two hydrogen production systems, and the two hydrogen production systems are both connected to the hydrogen gas cabinet (1); The hydrogen production system comprises a hydrogen preparation system, a gas-liquid separation system, a water-adding alkali supplementation circulation system, and a power supply and distribution and control system. The hydrogen preparation system is connected to the gas-liquid separation system, and the gas-liquid separation system is connected to the water-adding alkali supplementation circulation system. The power supply and distribution and control system are respectively connected to the hydrogen preparation system, the gas-liquid separation system, and the water-adding alkali supplementation circulation system by electric wires. Two hydrogen preparation systems and two gas-liquid separation systems are each provided, and the two hydrogen preparation systems correspond to the two gas-liquid separation systems one by one. The hydrogen preparation system comprises an electrolytic cell (3), wherein water in the electrolytic cell (3) is decomposed into hydrogen and oxygen under the action of electric current; The gas-liquid separation system comprises a hydrogen gas-liquid cooling separator (4) and an oxygen gas-liquid cooling separator (4), and the electrolyzer (3) of the hydrogen preparation system is connected to the hydrogen gas-liquid cooling separator (4) and the oxygen gas-liquid cooling separator (4), respectively; The water-adding alkali-supplementing circulation system comprises a circulating alkali tank (6) and a pure water storage tank (7), wherein the pure water storage tank (7) is connected to the circulating alkali tank (6); The circulating alkali tank (6) is connected to two elbows (9), and the two elbows (9) correspond to the hydrogen gas-liquid cooling separator (4) and the oxygen gas-liquid cooling separator (4) respectively. The liquid outlet of the hydrogen gas-liquid cooling separator (4) and the liquid outlet of the oxygen gas-liquid cooling separator (4) are both connected to the circulating alkali tank (6) through the elbows (9). The gas outlet of the hydrogen gas-liquid cooling separator (4) is connected to the hydrogen main pipe, and the gas outlet of the oxygen gas-liquid cooling separator (4) is connected to the oxygen main pipe. The electrolyzer (3) is connected to the circulating alkali tank (6), and the circulating pump (10) is used to realize the circulation of electrolyte between the electrolyzer (3), the hydrogen gas-liquid cooling separator (4) and the oxygen gas-liquid cooling separator (4). The circulating alkali tank (6) is connected to the hydrogen gas cabinet (1) through a water mist collector (11).
2. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The curved pipe (9) is U-shaped.
3. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The height of the curved pipe (9) is 4 m.
4. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The working process of the power supply and distribution and control system is as follows: Set up the interlocking process. When the interlocking input signal is abnormal, in order to ensure that the hydrogen production device is shut down and effectively handled, the specific operations are as follows; 1.
1. Low flow alarm interlock of cathode and anode electrolyte in electrolytic cell (3). If the electrolyte flow rate LL exceeds 5 seconds, the system will stop. 1.
2. The rectifier fault cannot be restored, the system stops and enters the automatic processing program; 1.
3. If the hydrogen-oxygen pressure difference at the outlet of electrolyzer (3) exceeds the HH value for 5 seconds, the system will be shut down; 1.
4. If the oxygen and hydrogen content at the outlet of the electrolyzer (3) exceeds the HH value for 3 seconds, the system will be shut down; 1.
5. The total voltage of the electrolytic cell (3) and the voltage of each unit are monitored online. If the HH or LL voltage is abnormal for more than 5 seconds, the system will be shut down.
5. A bipolar electrolyzer water hydrogen production process according to claim 4, characterized in that: After parking, the system interlocks automatically and the following are the output signals: 2.
1. The cathode liquid water supply valve is cut off, the flow rate is 0, and the pump is frequency-controlled; 2.
2. The valve from the hydrogen and oxygen pipeline to the user is automatically cut off, and the hydrogen and oxygen system can be filled with nitrogen for replacement and pressure maintenance; 2.
3. The circulation flow of anode and cathode is automatically adjusted to maintain circulation and a certain temperature.
6. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The nitrogen filling valve at the end of the anode and cathode main pipes of the electrolytic cell (3) 7. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The circulating alkali tank (6) is provided with a nitrogen filling pipeline.
8. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The pure water storage tank (7) transports the pure water to the circulating alkali tank (6) via a water pump (8).
9. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The hydrogen produced by the hydrogen production system enters the hydrogen gas tank (1), and the hydrogen in the hydrogen gas tank (1) is pressurized by the compressor (2) and transported to the customer.
10. A bipolar electrolyzer water hydrogen production process according to claim 1, characterized in that: The gas phase pressure of the cathode and anode of the electrolytic cell (3) is 20Kpa to 240Kpa.