PEM electrolytic cell-based green electricity hydrogen and oxygen production and air separation coupling system and process thereof

Abstract

The invention discloses a PEM electrolytic cell-based green electricity hydrogen and oxygen production and air separation coupling system, which comprises a PEM electrolytic cell, an oxygen outlet of the PEM electrolytic cell is directly connected to an air inlet of an air separation device through a pipeline; the intelligent pressure control system can dynamically adjust the operation pressure of the PEM electrolytic bath and the air inlet pressure of the air separation device in real time, so that the pressure matching precision of the PEM electrolytic bath and the air inlet pressure is controlled within the range of + / -0.05 MPa; the heat exchanger is arranged between the PEM electrolytic cell and the air separation device and used for preheating inlet air of the air separation device through waste heat generated by the PEM electrolytic cell. Through system-level coupling, dynamic pressure matching, double-effect heat recovery and multi-parameter collaborative optimization, efficient integration of the PEM electrolytic cell and the air separation system is achieved, the system performance is remarkably improved, and the industrial defects of low oxygen utilization rate, high compression energy consumption and low heat efficiency in a traditional process are overcome.

Description

Technical Field

[0001] This invention relates to a green electricity generation hydrogen and oxygen production and air separation coupling system based on a PEM electrolyzer and its process, belonging to the field of renewable energy technology. Background Technology

[0002] Currently, in the fields of renewable energy hydrogen production and industrial gas separation, proton exchange membrane electrolyzers and air separation systems are typically operated as two independent units. This independent operation mode suffers from a series of significant technical bottlenecks and resource waste, specifically manifested in the following aspects:

[0003] First, oxygen resources are severely wasted. PEM electrolyzers produce high-purity oxygen as a byproduct during hydrogen production, with a stoichiometric ratio approximately half that of hydrogen. In existing technologies, this valuable oxygen resource is typically not effectively utilized, but rather directly discharged or simply stored, resulting in a long-term oxygen utilization rate of less than 50% for the entire system. This not only wastes resources but also fails to realize the full value of the electrolytic hydrogen production unit as a gas production unit.

[0004] Secondly, the system has high energy consumption. Because the electrolyzer and air separation unit operate independently, the oxygen produced by electrolysis must be transported through pipelines and requires additional compression equipment to match the inlet pressure requirements of the air separation unit if it is to be utilized. This pressure mismatch and intermediate transportation links significantly increase the system's compression energy consumption; it is estimated that compression energy consumption increases by approximately 12.3%, thereby lowering the overall system energy efficiency, typically below 60%. Furthermore, the independent system design requires separate compressors, storage equipment, and control systems, as well as dedicated pipelines and facilities for intermediate oxygen storage and transportation. This increases the system's complexity and initial investment cost; compared to an integrated solution, equipment investment costs increase by approximately 15%.

[0005] Finally, the system's waste heat is not recovered, resulting in low thermal efficiency. The PEM electrolyzer generates approximately 80°C of low-grade waste heat during operation. In existing technologies, this heat is typically discharged directly into the environment through the cooling system, failing to be effectively recovered and utilized. This leads to the system's thermal energy not being utilized in a cascade manner, resulting in overall low thermal efficiency.

[0006] The existing technology mainly consists of three parts: a PEM electrolyzer, an oxygen storage device, and an air separation device. There is a lack of effective process coordination and system-level coupling between the links, such as the existing patent technologies with patent numbers CN112609406A and US20210086245A1.

[0007] Although there are improvements to PEM electrolyzers or air separation devices in existing technologies, none of them have proposed an overall solution that couples the two at the system level. In particular, there is a lack of key innovative designs such as dynamic pressure matching control and dual-effect heat recovery, which has led to the long-term existence of the industry pain points of low oxygen utilization, low system energy efficiency and high investment costs.

[0008] Therefore, there is an urgent need in this field for a revolutionary technology and system that can achieve efficient integration of PEM electrolyzers and air separation systems, full utilization of resources, and significant reduction in energy consumption. Summary of the Invention

[0009] The purpose of this invention is to provide a green electricity hydrogen and oxygen production and air separation coupling system based on a PEM electrolyzer, and also to provide a green electricity hydrogen and oxygen production and air separation coupling process based on a PEM electrolyzer. This invention aims to solve the technical bottlenecks caused by the independent operation of traditional PEM electrolyzers and air separation systems, such as waste of oxygen resources, high compression energy consumption, and low thermal efficiency.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0011] A green electricity production and air separation coupling system based on a PEM electrolyzer includes a PEM electrolyzer, an air separation device, an intelligent pressure control system, and a heat exchanger.

[0012] The oxygen outlet of the PEM electrolyzer is directly connected to the air inlet of the air separation device through a pipeline, forming an integrated process without intermediate storage. Deionized water is input into the PEM electrolyzer, and oxygen is produced as a byproduct while electrolyzing hydrogen. The process is powered by green electricity from wind and solar power.

[0013] The intelligent pressure control system can dynamically adjust the operating pressure of the PEM electrolyzer and the inlet pressure of the air separator in real time, so that the pressure matching accuracy of the two is controlled within ±0.05MPa, and the oxygen supply and demand balance is dynamically adjusted in real time.

[0014] The heat exchanger is located between the PEM electrolysis cell and the air separation device, and is used to preheat the air intake of the air separation device with the waste heat generated by the PEM electrolysis cell, so as to achieve efficient heat recovery.

[0015] In the aforementioned system, the operating pressure range of the PEM electrolyzer is 0.8 to 1.2 MPa, and the inlet pressure range of the air separator is 0.5 to 1 MPa.

[0016] In the aforementioned system, the current density of the PEM electrolyzer is 2.0–2.1 A / cm². 2 .

[0017] In the aforementioned system, the waste heat utilized by the heat exchanger is at a temperature of 80–85°C.

[0018] In the aforementioned system, the PEM electrolytic cell, air separation device, intelligent pressure control system, and heat exchanger are all connected by pipelines, the length of which does not exceed 50 meters, and there are no intermediate storage devices.

[0019] A green electricity generation process for hydrogen and oxygen production coupled with air separation based on a PEM electrolyzer includes the following steps:

[0020] A. Deionized water is fed into a PEM electrolyzer for electrolysis to produce hydrogen and oxygen as a byproduct.

[0021] B. The by-product oxygen is directly fed into the air separation device without intermediate storage and transportation;

[0022] C. The operating pressure of the PEM electrolyzer and the inlet pressure of the air separation device are dynamically adjusted in real time by the intelligent pressure control system so that the pressure matching accuracy between the two is controlled within ±0.05MPa.

[0023] D. The waste heat generated by the PEM electrolysis cell is used to preheat the air intake of the air separation device through a heat exchanger.

[0024] In the aforementioned process, the operating pressure range of the PEM electrolyzer is 0.8 to 1.2 MPa, and the inlet pressure range of the air separation device is 0.5 to 1 MPa.

[0025] In the aforementioned process, the current density of the PEM electrolytic cell is 2.0–2.1 A / cm². 2 .

[0026] In the aforementioned process, the waste heat preheating temperature is 80–85°C.

[0027] The aforementioned process also includes multi-parameter coordinated optimization of current density, electrolytic cell pressure, air separation pressure and heat recovery temperature, with the goal of maximizing the overall efficiency of the system.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] (1) This invention effectively improves the utilization rate of resources. By directly connecting the by-product oxygen from electrolysis to the air separation unit, the intermediate storage and transportation losses are eliminated, and the oxygen utilization rate is increased from 50% in the traditional process to more than 98.5%, realizing the high-value and full-quantity utilization of by-product resources.

[0030] (2) The energy efficiency and thermal efficiency of the system of the present invention have been significantly optimized. The overall energy efficiency of the system has been increased from 55% of the traditional process to 68.5%, an increase of 13.5 percentage points. Furthermore, the innovative dynamic pressure matching control has solved the problem of oxygen supply and demand pressure imbalance, avoiding additional compression requirements and reducing compression energy consumption. It also utilizes the waste heat of the electrolytic cell at 80-85℃ to preheat the air separation intake, realizing the cascade utilization of energy and improving the thermal efficiency of the system.

[0031] (3) The present invention has good economic benefits. The integrated process eliminates the need for separate oxygen storage, transportation and some compression equipment, thereby reducing the initial investment cost of the system. The reduction in energy consumption and the improvement in resource utilization directly reduce the long-term operating cost of the system.

[0032] (4) This invention enhances the reliability and technical synergy of the system. By controlling key parameters such as current density, pressure and temperature in a coordinated manner, it breaks through the bottleneck of single parameter optimization and maximizes the overall efficiency of the system. Dynamic pressure matching, dual-effect heat recovery and multi-parameter coordination constitute a complementary innovation system, which together ensures the efficient and stable operation of the system under different working conditions. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the coupling system and control principle of the present invention. Detailed Implementation

[0034] In existing technologies, oxygen produced as a byproduct of PEM electrolyzers is typically discharged or stored after simple treatment, resulting in oxygen utilization rates remaining below 50% for extended periods. The lack of process synergy between the air separation system and the electrolyzer leads to a 12.3% increase in compression energy consumption during oxygen transport. Furthermore, the 80°C waste heat generated by the electrolyzer is not recovered, resulting in an overall system thermal efficiency of less than 60%. These issues contribute to low system energy efficiency (55%) and high investment costs (an increase of 15%), making it difficult to meet the high-efficiency requirements of green electricity-to-hydrogen production under the "dual-carbon" strategy. This invention achieves a breakthrough in system-level coupling of "electrolysis water-air separation," directly connecting the by-product oxygen from the PEM electrolyzer to the air inlet of the air separator, eliminating losses during intermediate oxygen storage and transportation. It innovatively proposes dynamic pressure matching control (real-time dynamic adjustment of the electrolyzer pressure (0.8-1.2 MPa) and the air separation pressure (0.5-1 MPa), with an accuracy of ±0.05 MPa) to solve the oxygen supply-demand imbalance problem. A dual-effect heat recovery system is designed to preheat the air inlet of the air separator using waste heat from the electrolyzer, improving the system's thermal efficiency by 8%. Furthermore, it achieves multi-parameter synergistic optimization of current density, pressure, and heat recovery, increasing the system's energy efficiency to 68.5%.

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] Embodiment 1 of the present invention: A green electricity production hydrogen and oxygen and air separation coupling system based on PEM electrolyzer, comprising a PEM electrolyzer, an air separation device, an intelligent pressure control system and a heat exchanger;

[0037] The oxygen outlet of the PEM electrolyzer is directly connected to the air inlet of the air separator via a pipeline, forming an integrated process without intermediate storage. Deionized water is fed into the PEM electrolyzer, which produces hydrogen as a byproduct during electrolysis. The electrolyzer is powered by green electricity from wind and solar power. The current density of the PEM electrolyzer is precisely 2-2.1 A / cm³. 2 The electrolyzer pressure is precisely controlled at 0.8-1.1 MPa, and the hydrogen production rate is 180-220 Nm³. 3 At the same time, it produces 90-110 Nm³ of oxygen per hour. 3 / h, electrolysis by-product oxygen is directly fed into the air separator, with an inlet pressure of 0.5-0.8MPa and an accuracy of ±0.05MPa;

[0038] The intelligent pressure control system can dynamically adjust the operating pressure of the PEM electrolyzer and the inlet pressure of the air separator in real time, so that the pressure matching accuracy of the two is controlled within ±0.05MPa, and the oxygen supply and demand balance is dynamically adjusted in real time.

[0039] A heat exchanger is installed between the PEM electrolyzer and the air separator to preheat the air intake of the air separator using the waste heat generated by the PEM electrolyzer. The waste heat of 80-85℃ generated by the electrolyzer preheats the air intake for air separation via the heat exchanger, separating out 85.5-100 Nm³ of oxygen. 3 / h and nitrogen 45-52.5Nm 3 / h, achieving efficient heat energy recovery.

[0040] Specifically, the PEM electrolyzer, air separation unit, intelligent pressure control system and heat exchanger are all connected by pipelines with a length not exceeding 50 meters and no intermediate storage equipment, forming a closed loop.

[0041] This embodiment achieves precise control of the current density at 2-2.1 A / cm². 2 Key parameters such as electrolytic cell pressure (0.8-1.1 MPa), air separation pressure (0.5-0.8 MPa), and heat recovery temperature (80-85℃) ensure immediate oxygen utilization, dynamic pressure matching, and efficient heat recovery.

[0042] Embodiment 2 of the present invention: A green electricity generation process for hydrogen and oxygen production and air separation coupling based on a PEM electrolyzer, comprising the following steps:

[0043] A. Deionized water is fed into a PEM electrolyzer for electrolysis, producing hydrogen and oxygen as a byproduct. The operating pressure range of the PEM electrolyzer is 0.8–1.2 MPa, and the current density is 2.0–2.1 A / cm³. 2 ;

[0044] B. The by-product oxygen is directly fed into the air separator without intermediate storage and transportation. The air separator's inlet pressure range is 0.5 to 1 MPa.

[0045] C. The operating pressure of the PEM electrolyzer and the inlet pressure of the air separator are dynamically adjusted in real time by the intelligent pressure control system, so that the pressure matching accuracy of the two is controlled within ±0.05MPa.

[0046] D. The waste heat generated by the PEM electrolysis cell is used to preheat the air intake of the air separation device through a heat exchanger. The waste heat preheating temperature is 80-85℃.

[0047] E. Perform multi-parameter collaborative optimization on current density, electrolytic cell pressure, air separation pressure and heat recovery temperature, with the goal of maximizing the overall efficiency of the system.

[0048] Specifically, deionized water is prepared through the following steps: tap water is filtered through a reverse osmosis membrane and then treated with ion exchange resin, with the final conductivity accurate to 0.08 μS / cm.

[0049] Specifically, compressed air is used after being dehumidified by a drying tower.

[0050] The present invention will be further explained below through specific experimental embodiments and comparative examples.

[0051] Example 3:

[0052] A full-system simulation model was built in Aspen software. The experimental materials included:

[0053] 99.9% pure deionized water (preparation steps: tap water is filtered through a reverse osmosis membrane and then treated with ion exchange resin, with the final conductivity accurate to 0.08 μS / cm);

[0054] Compressed air pressure 0.8MPa (used after dehumidification in a drying tower).

[0055] Experimental steps:

[0056] Deionized water was fed into the PEM electrolyzer (PEM 500 model, rated power 500kW), and the current density was set precisely to 2A / cm³. 2The electrolyzer pressure is set to 0.8 MPa; the air separation unit's inlet pressure is dynamically adjusted to 0.5 MPa in real time via an intelligent pressure control system (adjustment accuracy ±0.05 MPa) to achieve an immediate balance between oxygen production and air separation requirements. Electrolysis byproduct oxygen is directly input into the air separation unit via a ≤50-meter pipeline without intermediate storage. After 10 hours of continuous operation, the electrolysis hydrogen production is 200 Nm³. 3 / h, by-product oxygen 100Nm 3 / h; the air separation unit separates 95Nm of oxygen. 3 / h and nitrogen 50Nm 3 / h; The oxygen utilization rate and system energy efficiency are recorded in real time throughout the process. After three repeated simulations, the oxygen utilization rate is stable at 95.2% (standard deviation ±0.15%) and the system energy efficiency is 62.3% (standard deviation ±0.18%).

[0057] This embodiment solves the compression energy consumption problem caused by oxygen supply and demand imbalance in existing technologies (such as patent documents CN112609406A and US20210086245A1) for the first time by using an innovative dynamic pressure matching mechanism (real-time dynamic adjustment of electrolytic cell pressure 0.8MPa and air separation pressure 0.5MPa with an accuracy of ±0.05MPa). This reduces compression energy consumption by 12.3% and improves system energy efficiency by 7.3 percentage points compared with traditional processes (55.0%).

[0058] This embodiment independently focuses on the process coupling of electrolyzer and air separation, without involving the production of synthetic ammonia or nitric acid. Its innovation lies in proposing a "dynamic pressure matching" control strategy to achieve real-time balance between oxygen supply and demand, avoiding additional compression equipment, providing basic technical support for the field of green electricity hydrogen production, and can be widely applied to high-purity nitrogen demand scenarios such as semiconductors and medical applications.

[0059] Example 4:

[0060] A full-system simulation model was built in Aspen software. Experimental materials:

[0061] 99.9% pure deionized water (preparation steps: tap water is filtered through a reverse osmosis membrane and then treated with ion exchange resin, with the final conductivity accurate to 0.08 μS / cm);

[0062] Compressed air pressure 0.8MPa (used after dehumidification in a drying tower).

[0063] Experimental steps:

[0064] Deionized water is fed into a PEM electrolyzer (PEM 500 model, rated power 500kW), with the current density set precisely at 2A / cm² and the electrolyzer pressure set at 1MPa. The air inlet pressure of the air separator is dynamically adjusted in real-time to 0.7MPa (accuracy ±0.05MPa) via an intelligent pressure control system to achieve immediate oxygen supply and demand balance. Simultaneously, the waste heat generated by the electrolyzer at 80℃ is used to preheat the air inlet gas for air separation via a heat exchanger, and then the gas is directly fed into the air separator via a ≤50-meter pipeline without intermediate storage. After 10 hours of continuous operation, the electrolysis hydrogen production is 200 Nm³. 3 / h, by-product oxygen 100Nm 3 / h; the air separator separated 97.8 Nm of oxygen. 3 / h and nitrogen 50Nm 3 / h; key indicators were recorded in real time throughout the process. After three repeated simulations, the oxygen utilization rate was stable at 97.8% (standard deviation ±0.12%), and the system energy efficiency was 67.3% (standard deviation ±0.10%).

[0065] This embodiment, through an innovative dual-effect heat recovery design (using waste heat from the electrolyzer to preheat the intake gas), solves for the first time the problem of low thermal efficiency caused by unutilized waste heat in existing technologies, improving system thermal efficiency by 8% and system energy efficiency by 4.9 percentage points compared to Embodiment 1. It complements the dynamic pressure matching of Embodiment 1, together forming the core innovation system of this patent, providing fundamental technical support for the field of green electricity-to-hydrogen production.

[0066] Example 5:

[0067] A full-system simulation model was built in Aspen software. Experimental materials:

[0068] 99.9% pure deionized water (preparation steps: tap water is filtered through a reverse osmosis membrane and then treated with ion exchange resin, with the final conductivity accurate to 0.08 μS / cm);

[0069] Compressed air pressure 0.8MPa (used after dehumidification in a drying tower).

[0070] Experimental steps:

[0071] Deionized water was fed into the PEM electrolyzer (PEM 500 model, rated power 500kW), and the current density was set precisely to 2.1A / cm³. 2 The electrolyzer pressure is set to 1.1 MPa; the intelligent control system optimizes the air separator inlet pressure to 0.8 MPa (accuracy ±0.05 MPa) and the heat recovery temperature to 85℃ in real time, achieving multi-parameter coordination of current density, pressure, and heat recovery; the by-product oxygen from electrolysis is directly input into the air separator via a ≤50-meter pipeline without intermediate storage, and after 10 hours of continuous operation, the hydrogen production is 210 Nm³.3 / h, byproduct oxygen 105 Nm 3 / h; the air separator separated 98.5 Nm of oxygen. 3 / h and nitrogen 52.5Nm 3 / h; key indicators are recorded in real time throughout the process. After three repeated simulations, the oxygen utilization rate is stable at 98.5% (standard deviation ±0.10%) and the system energy efficiency is 68.5% (standard deviation ±0.08%).

[0072] This embodiment utilizes innovative multi-parameter collaborative optimization control (current density 2.1 A / cm²). 2 The system, with an electrolytic cell pressure of 1.1 MPa, an air separation pressure of 0.8 MPa, and a heat recovery temperature of 85°C, is the first to solve the system efficiency bottleneck caused by single parameter optimization in existing technologies. This improves the system energy efficiency by 1.2 percentage points and the oxygen utilization rate by 0.7 percentage points compared to Example 4. Together with Example 3 (dynamic pressure matching) and Example 4 (dual-effect heat recovery), it forms a complementary and innovative system, constituting the core technological pillar of this patent.

[0073] Comparative example (traditional process):

[0074] Based on the independent operation mode of the PEM electrolyzer and the air separation system, process coupling and dynamic optimization have not been achieved.

[0075] Experimental materials:

[0076] 99.9% pure deionized water (preparation steps: tap water is filtered through a reverse osmosis membrane and then treated with ion exchange resin, with conductivity accurate to 0.08 μS / cm);

[0077] Compressed air pressure 0.8MPa (used after dehumidification in a drying tower).

[0078] Experimental steps:

[0079] Deionized water was fed into the PEM electrolyzer (PEM 500 model, rated power 500kW), and the current density was set precisely to 2A / cm³. 2 The electrolyzer pressure is precisely 0.8 MPa, and after 10 hours of continuous operation, the hydrogen production is 200 Nm³. 3 / h, by-product oxygen 100Nm 3 / h; Electrolysis byproduct oxygen is transported via a 50-meter pipeline to an air separator (operating pressure precisely 0.7 MPa). Additional compression equipment is required to regulate the pressure, separating 50 Nm³ of oxygen. 3 / h and nitrogen 50Nm 3 / h; Meanwhile, the 80℃ waste heat generated by the electrolytic cell is directly discharged without heat recovery; the oxygen utilization rate and system energy efficiency are recorded in real time throughout the process. After three repeated simulations, the oxygen utilization rate is stable at 50% (standard deviation ±0.20%) and the system energy efficiency is 55% (standard deviation ±0.25%).

[0080] This comparative example clearly demonstrates the three major drawbacks of the traditional process: low oxygen utilization (50%), high compression energy consumption (increased by 12.3%), and low thermal efficiency (no waste heat recovery). This contrasts sharply with Example 5: oxygen utilization is 48.5 percentage points lower, system energy efficiency is 13.5 percentage points lower, and investment costs are 15% higher. This comparative example focuses only on the independent operation of the electrolyzer and air separation, without involving the ammonia or nitric acid production process, fully presenting the inefficiency of the traditional process. It provides a precise comparative basis for the system-level coupling, dynamic pressure matching, dual-effect heat recovery, and multi-parameter synergistic optimization of this invention.

[0081] Table 1: Key Parameters and Performance Indicators of the Example

[0082]

[0083] Table 2: Comparison of Performance between Examples and Traditional Processes

[0084] Project Conventional process Example 3 Example 4 Example 5 Oxygen utilization (%) 50 95.2 97.8 98.5 System energy efficiency (%) 55 62.3 67.3 68.5 Oxygen utilization improvement (%) - 45.2 47.8 48.5 System energy efficiency improvement (%) - 7.3 12.3 13.5 Compressed energy consumption reduction (%) - 12.3 12.3 12.3 Thermal efficiency improvement (%) - 0 8 8

[0085] Note: All data are based on Aspen software simulation verification. After three repeated experiments, the standard deviation is <0.2%, and the consistency reaches over 99.5%. Example 3 solves the oxygen supply and demand imbalance problem through dynamic pressure matching; Example 4 improves thermal efficiency through double-effect heat recovery; Example 5 maximizes system efficiency through multi-parameter collaborative optimization. This invention focuses on the process coupling of electrolyzer and air separation, and innovatively proposes system-level coupling, dynamic pressure matching, double-effect heat recovery, and multi-parameter collaborative optimization technologies, solving the industry pain points of low oxygen utilization (<50%), high compression energy consumption (12.3%), and low thermal efficiency (no waste heat recovery) in traditional processes.

Claims

1. A green electricity generation and air separation coupling system based on a PEM electrolyzer, characterized in that, Includes PEM electrolyzer, air separation unit, intelligent pressure control system and heat exchanger; The oxygen outlet of the PEM electrolyzer is directly connected to the air inlet of the air separator via a pipeline. The intelligent pressure control system can dynamically adjust the operating pressure of the PEM electrolyzer and the inlet pressure of the air separator in real time, so that the pressure matching accuracy between the two is controlled within ±0.05MPa. The heat exchanger is located between the PEM electrolysis cell and the air separation device, and is used to preheat the air intake of the air separation device with the waste heat generated by the PEM electrolysis cell.

2. The system according to claim 1, characterized in that, The operating pressure range of the PEM electrolyzer is 0.8 to 1.2 MPa, and the inlet pressure range of the air separator is 0.5 to 1 MPa.

3. The system according to claim 1, characterized in that, The current density of the PEM electrolyzer is 2.0–2.1 A / cm². 2 .

4. The system according to claim 1, characterized in that, The waste heat utilized by the heat exchanger is at a temperature of 80–85°C.

5. The system according to claim 1, characterized in that, The PEM electrolytic cell, air separation device, intelligent pressure control system and heat exchanger are all connected by pipelines, the length of which does not exceed 50 meters and there is no intermediate storage equipment.

6. A green electricity generation process for hydrogen and oxygen production coupled with air separation based on a PEM electrolyzer, characterized in that, Includes the following steps: A. Deionized water is fed into a PEM electrolyzer for electrolysis to produce hydrogen and oxygen as a byproduct. B. The by-product oxygen is directly fed into the air separation device without intermediate storage and transportation; C. The operating pressure of the PEM electrolyzer and the inlet pressure of the air separation device are dynamically adjusted in real time by the intelligent pressure control system so that the pressure matching accuracy between the two is controlled within ±0.05MPa. D. The waste heat generated by the PEM electrolysis cell is used to preheat the air intake of the air separation device through a heat exchanger.

7. The process according to claim 6, characterized in that, The operating pressure range of the PEM electrolyzer is 0.8 to 1.2 MPa, and the inlet pressure range of the air separator is 0.5 to 1 MPa.

8. The process according to claim 6, characterized in that, The current density of the PEM electrolyzer is 2.0–2.1 A / cm². 2 .

9. The process according to claim 6, characterized in that, The waste heat preheating temperature is 80-85℃.

10. The process according to claim 6, characterized in that, It also includes multi-parameter coordinated optimization of current density, electrolytic cell pressure, air separation pressure and heat recovery temperature, with the goal of maximizing the overall efficiency of the system.

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