Methanol fuel cell and photovoltaic synergetic carbon dioxide electrolytic hydrogen production system and method

Abstract

The invention relates to the technical field of renewable energy power generation, in particular to a methanol fuel cell and photovoltaic synergetic carbon dioxide electrolytic hydrogen production system and method. The system comprises a methanol reforming module, a fuel cell module, a gas turbine module, a photovoltaic power generation module and a solid oxide electrolytic cell module, the methanol reforming module firstly converts methanol and water into hydrogen-rich synthesis gas, then the hydrogen-rich synthesis gas is conveyed to the fuel cell module for power generation, and the generated electric energy is directly supplied to the solid oxide electrolytic cell module for electrolytic reaction; the gas turbine module cooperates with the output of the fuel cell to jointly meet the lowest load requirement of the electrolytic cell, and the photovoltaic power generation module increases the operation load of the electrolytic cell by supplementing electric energy, so that the electrolytic cell is always kept in an efficient hydrogen production interval. And capture and resource conversion of carbon dioxide are realized.

Description

Technical Field

[0001] This invention relates to the field of renewable energy power generation technology, and in particular to a system and method for producing hydrogen by carbon dioxide electrolysis in conjunction with a methanol fuel cell and photovoltaics. Background Technology

[0002] Hydrogen energy, as a high-energy-density secondary energy source with zero carbon emissions during its utilization, is widely considered to play a core role in the future energy system, particularly suitable for transportation, industrial raw materials, and grid energy storage. However, currently, over 95% of hydrogen production still relies on fossil fuel reforming processes, which are accompanied by significant carbon dioxide emissions. The actual cleanliness of "green hydrogen" is highly dependent on the carbon footprint of its production process. Therefore, developing hydrogen production systems based on renewable energy sources that can achieve carbon recycling or even negative carbon emissions has become a key technological path for promoting energy structure transformation.

[0003] Among various green hydrogen production technologies, the high-temperature solid oxide electrolysis cell (SOEC) offers a new approach to achieving efficient carbon resource recycling due to its high electrochemical efficiency at high temperatures and its ability to simultaneously electrolyze carbon dioxide and water vapor (co-electrolysis) to produce syngas. However, SOEC technology still faces a series of challenges in practical application: on the one hand, its efficient and stable operation heavily relies on a continuous and stable high-temperature environment and power supply, placing extremely high demands on the system's thermal and electrical management; on the other hand, highly volatile renewable energy sources (such as solar and wind power) cannot independently meet the continuous and efficient operating load requirements of SOEC, especially under conditions of no sunlight or low wind speed, where system performance will significantly decline. More importantly, to achieve practically meaningful carbon capture and utilization (CCU), a stable and inexpensive carbon dioxide source and an efficient conversion pathway must be provided.

[0004] In summary, existing green hydrogen production technologies still have significant shortcomings in addressing the volatility of renewable energy, ensuring the continuous and stable operation of SOEC, and achieving low-cost carbon cycling. There is an urgent need to develop a new integrated system that can integrate the advantages of multiple energy sources and achieve efficient and synergistic conversion of electricity, hydrogen, and carbon. Summary of the Invention

[0005] The purpose of this invention is to provide a carbon dioxide electrolysis hydrogen production system and method that combines methanol fuel cells and photovoltaics, aiming to build a green hydrogen production and carbon resource utilization system with good technical and economic efficiency and operational reliability through multi-module collaboration, energy cascade utilization and intelligent control strategies.

[0006] To achieve the above objectives, the present invention provides a methanol fuel cell and photovoltaic synergy carbon dioxide electrolysis hydrogen production system. The system includes a methanol reforming module, a fuel cell module, a gas turbine module, a photovoltaic power generation module, and a solid oxide electrolyzer module. The methanol reforming module is connected to the fuel cell module via a pipeline. Both the fuel cell module and the methanol reforming module are connected to the gas turbine module. The fuel cell module, the gas turbine module, and the photovoltaic power generation module are all connected to the solid oxide electrolyzer module via cables. The solid oxide electrolyzer module is connected to the carbon dioxide exhaust port of the gas turbine module via a pipeline. The methanol reforming module is used to convert methanol and water into hydrogen-rich syngas and deliver it to the fuel cell module. The fuel cell module is used to convert the chemical energy in hydrogen-rich syngas into electrical energy through an electrochemical reaction. The gas turbine module is used to burn the exhaust gas produced after the fuel cell module operates and the residual gas produced after the methanol reforming module operates, to drive the generator to generate supplementary electrical energy, and at the same time discharge the carbon dioxide-containing mixed gas produced by combustion. The photovoltaic power generation module is used to convert solar energy into electrical energy; The solid oxide electrolyzer module is used to receive the carbon dioxide-containing mixed gas output from the gas turbine module and the externally supplemented water vapor, while receiving electrical energy from the fuel cell module, the gas turbine module and the photovoltaic power generation module, and to perform a co-electrolysis reaction on the input carbon dioxide-containing mixed gas and water vapor to generate hydrogen-rich syngas.

[0007] The methanol fuel cell and photovoltaic-coordinated carbon dioxide electrolysis hydrogen production system further includes a compressor module, a hydrogen purification module, a carbon dioxide storage tank, a first separator module, a second separator module, a mixer module, and a waste heat recovery power generation device. The compressor module is used to compress air and deliver the compressed air to the cathode of the fuel cell module; The hydrogen purification module is connected between the methanol reforming module and the fuel cell module. It is used to purify the hydrogen in the hydrogen-rich synthesis gas and deliver the high-purity hydrogen to the anode of the fuel cell module, and deliver the remaining gas to the gas turbine module. The carbon dioxide storage tank is used to collect carbon dioxide-containing mixed gas generated during the operation of the gas turbine module; The first separator module is connected to the anode outlet of the solid oxide electrolyzer module and is used to separate and collect the oxygen generated during electrolysis. The second separator module is connected to the cathode outlet of the solid oxide electrolyzer module and is used to separate and collect the hydrogen and carbon monoxide synthesis gas generated during electrolysis. The mixer module is used to mix the electrolyte from the first separator module and the second separator module and then return it to the solid oxide electrolytic cell module; The waste heat recovery power generation device is used to recover the high-temperature product gas from the anode and cathode outlets of the solid oxide electrolytic cell module and the waste heat from the exhaust gas of the gas turbine module, and convert it into supplementary electrical energy. The power output terminal of the waste heat recovery power generation device is connected to the solid oxide electrolytic cell module via a cable to provide it with some operating power.

[0008] The methanol reforming module is specifically configured to: introduce methanol and water together, and use the waste heat generated by the fuel cell module as the heat source for the reforming reaction to convert methanol and water into hydrogen-rich syngas. The hydrogen-rich syngas is then transported to the fuel cell module through a pipeline for power generation.

[0009] The fuel cell module is specifically configured to receive hydrogen-rich synthesis gas from the methanol reforming module, pass it into the anode of the fuel cell to undergo an electrochemical oxidation reaction, and simultaneously pass air into the cathode to undergo a reduction reaction. The electrochemical reaction between the two electrodes generates electrical energy to provide power for the subsequent electrolysis process.

[0010] The fuel cell module and the gas turbine module are both connected to the solid oxide electrolyzer module via cables. When the photovoltaic power generation module is unable to provide power to the solid oxide electrolyzer module, the fuel cell module and the gas turbine module continuously supply power to the solid oxide electrolyzer to ensure that it always meets the minimum operating load requirements.

[0011] The solid oxide electrolyzer module is specifically configured to receive carbon dioxide generated by the gas turbine module and externally supplemented carbon dioxide, while simultaneously introducing water vapor. Under the synergistic effect of electrolysis and high-temperature pyrolysis, carbon dioxide and water are converted into hydrogen-rich syngas.

[0012] This invention also provides a method for producing hydrogen by carbon dioxide electrolysis in conjunction with a methanol fuel cell and photovoltaic system, applicable to the methanol fuel cell and photovoltaic system for producing hydrogen by carbon dioxide electrolysis as described above, comprising the following steps: Using the thermal energy provided by the gas battery module, methanol and water undergo a reforming reaction in the methanol reforming module to generate hydrogen-rich syngas. The hydrogen-rich syngas is then separated by the hydrogen purification module to obtain high-purity hydrogen and carbon-containing tail gas. High-purity hydrogen is introduced into the anode of the fuel cell module, while air compressed by the compressor module is introduced into the cathode of the fuel cell module to carry out an electrochemical reaction to generate electricity and produce high-temperature exhaust gas. The carbon-containing exhaust gas generated by the hydrogen purification module and the high-temperature exhaust gas generated by the fuel cell module are fed into the gas turbine module for combustion, driving the generator to generate supplementary electrical energy and generating high-temperature flue gas rich in carbon dioxide. The high-temperature flue gas rich in carbon dioxide is then temporarily stored and buffered in the carbon dioxide storage tank. The buffered carbon dioxide-containing gas is mixed with externally supplied carbon dioxide and water vapor in the mixer module to form electrolysis feed gas; The electrical energy generated by the fuel cell module, the gas turbine module, and the photovoltaic power generation module is collected and delivered to the solid oxide electrolyzer module. When there is insufficient sunlight, the fuel cell module and the gas turbine module provide basic power to maintain the minimum operating load of the solid oxide electrolyzer module. When there is sufficient sunlight, the photovoltaic power generation module provides the main or incremental power to increase the operating load of the solid oxide electrolyzer module to the high-efficiency range. The electrolytic raw material gas obtained after mixing by the mixer module is introduced into the solid oxide electrolytic cell module. Under the action of electrical energy and high temperature, carbon dioxide and water vapor undergo a co-electrolysis reaction, generating a mixed synthesis gas of hydrogen and carbon monoxide at the cathode and generating oxygen at the anode. The oxygen generated at the anode of the solid oxide electrolyzer module is separated and collected by the first separator module, and the hydrogen and carbon monoxide mixed synthesis gas generated at the cathode is separated and collected by the second separator module. The high-temperature product gas at the outlet of the solid oxide electrolyzer module and the waste heat in the flue gas emitted by the gas turbine module are recovered and converted into supplementary electrical energy through the waste heat recovery power generation device, and fed back to the power supply system of the solid oxide electrolyzer module.

[0013] This invention discloses a methanol fuel cell and photovoltaic synergistic carbon dioxide electrolysis hydrogen production system and method, comprising a methanol reforming module, a fuel cell module, a gas turbine module, a photovoltaic power generation module, and a solid oxide electrolyzer module. The methanol reforming module first converts methanol and water into hydrogen-rich syngas, which is then fed to the fuel cell module to generate electricity. The generated electricity is directly supplied to the solid oxide electrolyzer module for the electrolysis reaction. The gas turbine module, in conjunction with the fuel cell module, outputs enough to meet the minimum load requirements of the electrolyzer. The photovoltaic power generation module supplements the electrolyzer's operating load by providing additional electricity, ensuring it remains within the high-efficiency hydrogen production range. This system introduces carbon dioxide generated from methanol reforming, the fuel cell, and the gas turbine, along with carbon dioxide and water vapor supplied from a carbon dioxide tank, into the solid oxide electrolyzer module, ultimately converting it into syngas. This technical solution effectively ensures the continuous and efficient operation of the solid oxide electrolyzer module, achieving carbon dioxide capture and resource conversion. Simultaneously, this system provides a feasible technical path for emission reduction and efficiency improvement in the industrial sector, and has practical significance for promoting energy structure transformation. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the principle of the methanol fuel cell and photovoltaic synergistic carbon dioxide electrolysis hydrogen production system provided by the present invention.

[0016] Figure 2 This is a flowchart of the steps of the method for producing hydrogen by carbon dioxide electrolysis in conjunction with methanol fuel cells and photovoltaics provided by the present invention.

[0017] 1-Compressor module, 2-Methanol reforming module, 3-Hydrogen purification module, 4-Fuel cell module, 5-Gas turbine module, 6-Carbon dioxide storage tank, 7-Photovoltaic power generation module, 8-Solid oxide electrolyzer module, 9-First separator module, 10-Second separator module, 11-Mixer module, 12-Waste heat recovery power generation device. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] Please see Figure 1 This invention provides a methanol fuel cell and photovoltaic synergy carbon dioxide electrolysis hydrogen production system. The methanol fuel cell and photovoltaic synergy carbon dioxide electrolysis hydrogen production system includes a methanol reforming module 2, a fuel cell module 4, a gas turbine module 5, a photovoltaic power generation module 7, and a solid oxide electrolyzer module 8. The methanol reforming module 2 is connected to the fuel cell module 4 through a pipeline. The fuel cell module 4 and the methanol reforming module 2 are both connected to the gas turbine module 5. The fuel cell module 4, the gas turbine module 5, and the photovoltaic power generation module 7 are all connected to the solid oxide electrolyzer module 8 through cables. The solid oxide electrolyzer module 8 is connected to the carbon dioxide discharge port of the gas turbine module 5 through a pipeline. The methanol reforming module 2 is used to convert methanol and water into hydrogen-rich syngas and deliver it to the fuel cell module 4. The fuel cell module 4 is used to convert the chemical energy in hydrogen-rich syngas into electrical energy through an electrochemical reaction. The gas turbine module 5 is used to burn the exhaust gas generated after the fuel cell module 4 operates and the residual gas generated after the methanol reforming module 2 operates, to drive the generator to generate supplementary electrical energy, and at the same time discharge the carbon dioxide-containing mixed gas generated by combustion. The photovoltaic power generation module 7 is used to convert solar energy into electrical energy; The solid oxide electrolyzer module 8 is used to receive the carbon dioxide-containing mixed gas output from the gas turbine module 5 and the externally supplemented water vapor, while also receiving electrical energy from the fuel cell module 4, the gas turbine module 5 and the photovoltaic power generation module 7, and to perform a co-electrolysis reaction on the input carbon dioxide-containing mixed gas and water vapor to generate hydrogen-rich syngas.

[0020] In this embodiment, the methanol reforming module 2 first converts methanol and water into hydrogen-rich syngas, which is then fed to the fuel cell module 4 to generate electricity. The generated electricity is directly supplied to the solid oxide electrolyzer module 8 for electrolysis. The gas turbine module 5, in conjunction with the fuel cell output, meets the minimum load requirement of the electrolyzer, while the photovoltaic power generation module 7 supplements the electrolyzer's operating load by providing additional electricity, ensuring it remains within the high-efficiency hydrogen production range. This system introduces carbon dioxide generated from methanol reforming, the fuel cell, and the gas turbine, along with carbon dioxide and water vapor supplied from the carbon dioxide tank, into the solid oxide electrolyzer module 8, ultimately converting it into syngas. This technical solution effectively ensures the continuous and efficient operation of the solid oxide electrolyzer module 8, achieving carbon dioxide capture and resource conversion. Simultaneously, this system provides a feasible technical path for emission reduction and efficiency improvement in the industrial sector, and has practical significance for promoting energy structure transformation.

[0021] Furthermore, the methanol fuel cell and photovoltaic-coordinated carbon dioxide electrolysis hydrogen production system also includes a compressor module 1, a hydrogen purification module 3, a carbon dioxide storage tank 6, a first separator module 9, a second separator module 10, a mixer module 11, and a waste heat recovery power generation device 12. The compressor module 1 is used to compress air and deliver the compressed air to the cathode of the fuel cell module 4; The hydrogen purification module 3 is connected between the methanol reforming module 2 and the fuel cell module 4. It is used to purify the hydrogen in the hydrogen-rich synthesis gas, and deliver the high-purity hydrogen to the anode of the fuel cell module 4, and deliver the remaining gas to the gas turbine module 5. The carbon dioxide storage tank 6 is used to collect carbon dioxide-containing mixed gas generated during the operation of the gas turbine module 5; The first separator module 9 is connected to the anode outlet of the solid oxide electrolyzer module 8 and is used to separate and collect the oxygen generated by electrolysis; The second separator module 10 is connected to the cathode outlet of the solid oxide electrolyzer module 8 and is used to separate and collect the hydrogen and carbon monoxide synthesis gas generated during electrolysis. The mixer module 11 is used to mix the electrolyte from the first separator module 9 and the second separator module 10 and then return it to the solid oxide electrolytic cell module 8; The waste heat recovery power generation device 12 is used to recover the high-temperature product gas from the anode and cathode outlets of the solid oxide electrolytic cell module 8 and the waste heat from the exhaust gas of the gas turbine module 5, and convert it into supplementary electrical energy. The power output terminal of the waste heat recovery power generation device 12 is connected to the solid oxide electrolytic cell module 8 via a cable to provide it with some operating power.

[0022] In this embodiment, air first enters the compressor module 1 for pressurization, and the compressed air is delivered to the cathode of the fuel cell module 4. Simultaneously, water and methanol enter the methanol reforming module 2, where a reforming reaction generates hydrogen-rich syngas. This syngas then enters the hydrogen purification module 3, where hydrogen is purified and delivered to the fuel cell module 4. The remaining gases enter the gas turbine module 5. In the fuel cell module 4, hydrogen undergoes an electrochemical oxidation reaction to generate electricity, and the exhaust gases from both the anode and cathode outlets are introduced into the gas turbine module 5. The electricity generated by the fuel cell module 4 supplies the solid oxide electrolyzer module 8 to produce hydrogen. The mixed gas is burned and expanded in the gas turbine module 5, driving a generator to produce electricity, which is also used to support the operation of the solid oxide electrolyzer module 8. The carbon dioxide-containing mixed gas at the system outlet first enters the carbon dioxide storage tank 6 for buffering, and then enters the mixer module 11, where it mixes with the liquid fluid at the outlet of the solid oxide electrolyzer module 8 before entering the electrolyzer. The electrical energy generated by the photovoltaic power generation module 7 is used to ensure the efficient and stable operation of the solid oxide electrolyzer module 8. In the electrolyzer, carbon dioxide and water are electrolyzed to produce hydrogen and carbon monoxide. The first separator module 9 and the second separator module 10 are used to separate the oxygen generated at the anode and the hydrocarbon fuel generated at the cathode of the solid oxide electrolyzer module 8, respectively.

[0023] Furthermore, the methanol reforming module 2 is specifically configured to: introduce methanol and water together, and use the waste heat generated by the fuel cell module 4 as the heat source for the reforming reaction to convert methanol and water into hydrogen-rich synthesis gas, which is then transported to the fuel cell module 4 through a pipeline for power generation.

[0024] Furthermore, the fuel cell module 4 is specifically configured to receive hydrogen-rich synthesis gas from the methanol reforming module 2, pass it into the anode of the fuel cell to undergo an electrochemical oxidation reaction, and simultaneously pass air into the cathode to undergo a reduction reaction. The electrochemical reaction between the two electrodes generates electrical energy to provide power for the subsequent electrolysis process.

[0025] Furthermore, both the fuel cell module 4 and the gas turbine module 5 are connected to the solid oxide electrolyzer module 8 via cables. When the photovoltaic power generation module 7 is unable to provide power to the solid oxide electrolyzer module 8, the fuel cell module 4 and the gas turbine module 5 continuously supply power to the solid oxide electrolyzer to ensure that it always meets the minimum operating load requirements.

[0026] Furthermore, the solid oxide electrolyzer module 8 is specifically configured to receive carbon dioxide generated from the gas turbine module 5 and externally supplemented carbon dioxide, while simultaneously introducing water vapor. Under the synergistic effect of electrolysis and high-temperature pyrolysis, carbon dioxide and water are converted into hydrogen-rich synthesis gas. Please see Figure 2 The present invention also provides a method for producing hydrogen by carbon dioxide electrolysis in conjunction with a methanol fuel cell and a photovoltaic system, applicable to the methanol fuel cell and photovoltaic system for producing hydrogen by carbon dioxide electrolysis as described above, comprising the following steps: S1: After being compressed by the compressor module 1, the air enters the cathode of the fuel cell module 4 to provide the oxygen required for the electrochemical reaction. At the same time, water and methanol enter the methanol reforming module 2 and are converted into a mixed gas under the action of a catalyst and high temperature. Its main components are hydrogen, water vapor, methanol, carbon dioxide and carbon monoxide. S2: The above-mentioned mixed gas enters the hydrogen purification module 3 for separation. The purified hydrogen is transported to the anode of the fuel cell module 4 as fuel for the electrochemical reaction. The remaining components, including water vapor, methanol, carbon dioxide and carbon monoxide, are introduced into the gas turbine module 5 for combustion and expansion to do work and drive power generation. S3: At the cathode of the fuel cell module 4, oxygen undergoes a reduction reaction to generate oxygen ions. These oxygen ions migrate to the anode via the electrolyte and combine with hydrogen ions generated by the oxidation of hydrogen at the anode to generate water vapor. This process is accompanied by the directional movement of electrons, thereby generating electrical energy. The mixed gas (mainly containing oxygen and nitrogen) at the cathode outlet of the fuel cell module 4 and the mixed gas (mainly containing hydrogen and water vapor) at the anode outlet are both introduced into the gas turbine module 5 for further utilization. S4: Water vapor, methanol, carbon dioxide and carbon monoxide from the outlet of the hydrogen purification module 3, together with oxygen, nitrogen, hydrogen and water vapor from the outlet of the fuel cell module 4, enter the gas turbine module 5 for combustion. The high-temperature gas after combustion expands and does work to drive power generation. S5: The carbon dioxide-containing mixed gas from the outlet of the gas turbine module 5 first enters the carbon dioxide storage tank 6 for buffering, and then is transported to the solid oxide electrolysis cell module 8. In the electrolysis cell, the water vapor in the mixed gas is electrolyzed to generate hydrogen, and the carbon dioxide is electrolyzed to generate carbon monoxide. Both are discharged from the cathode outlet. At the same time, the oxygen generated by electrolysis is discharged from the anode outlet. S6: Since the temperature of the mixed gas at the anode and cathode outlets of the solid oxide electrolysis cell module 8 is high, it needs to be cooled first, and then enters the first separator module 9 and the second separator module 10 for gas-liquid separation. After separation, the oxygen at the anode outlet is collected, and the hydrogen and carbon-based mixed fuel at the cathode outlet are collected separately. S7: The high-temperature mixed gas at the anode and cathode outlet of the solid oxide electrolyzer module 8 is thermally utilized by the waste heat recovery power generation device 12. The recovered heat energy is supplied to the waste heat recovery power generation device 12 for power generation. The electrical energy generated by the waste heat recovery power generation device 12, the fuel cell module 4, the gas turbine module 5, and the photovoltaic power generation module 7 are all used to drive the operation of the solid oxide electrolyzer module 8. In one specific embodiment, the methanol fuel cell and photovoltaic synergistic carbon dioxide electrolysis hydrogen production system of the present invention underwent a 24-hour continuous operation test in a typical sunny area of ​​Inner Mongolia, which fully verified its comprehensive performance of multi-energy coupling, energy cascade utilization and carbon resource conversion.

[0027] During nighttime and low-light periods (00:00 to 08:16 and 16:80 to 24:00), the system primarily relies on the combined power of the fuel cell module 4 and the gas turbine module 5. In this mode, the methanol reforming module 2 utilizes the waste heat from the fuel cell reaction to convert methanol and water into hydrogen-rich syngas, which is then supplied to the fuel cell for power generation. The generated electricity, along with waste heat power generation, maintains the minimum operating load of the solid oxide electrolyzer (SOEC). Actual measurement data shows that the SOEC operates stably during this period, with a stable current density of 0.1071 A / cm². 2 The average Faraday efficiency is 90.3%, and the overall system energy efficiency is approximately 41%. The hourly hydrogen production remains at 1.63–1.69 mol / s, the carbon monoxide production at 0.95–0.99 mol / s, and the total system input power remains stable at 1071.19 kW, demonstrating the system's self-sufficiency and operational reliability under light-free conditions.

[0028] During periods of abundant sunlight (08:16 to 16:80), the output power of the photovoltaic power generation module 7 increases significantly, working in conjunction with the fuel cell-waste heat system to drive the SOEC into a high-load, high-efficiency operating state. With the increase in photovoltaic input, the SOEC current density increases from 0.1071 A / cm². 2 It gradually increased, reaching a maximum of approximately 0.524 A / cm. 2 The Faraday efficiency was increased to over 99.3%. At high current densities, the electrolysis reaction rate increased significantly, with hydrogen production reaching a peak of approximately 11.41 mol / s and carbon monoxide production reaching a peak of approximately 6.66 mol / s. Simultaneously, the system voltage exhibited good thermal management characteristics with changes in temperature and current density, and the total system input power increased to a maximum of approximately 5240 kW. During this stage, the overall system energy efficiency was significantly improved, reaching a maximum of 84.8%, fully demonstrating the enhancing effect of photovoltaic energy on the system's hydrogen production efficiency.

[0029] The integrated high-temperature waste heat recovery power generation device 12 further improves the overall energy efficiency. The ORC module effectively recovers the low- and medium-temperature heat emitted by the SOEC and fuel cells and converts it into electricity, realizing the cascade utilization of energy. Operational data shows that the ORC power generation varies with the main system load, outputting approximately 48–49 kW during low-load periods and reaching a maximum of 335 kW during high-load periods, greatly improving the overall economy and energy utilization rate of the system.

[0030] After 24 hours of continuous operation, the system produced approximately 0.85 tons of hydrogen and 6.98 tons of carbon monoxide, and successfully achieved carbon dioxide resource conversion, absorbing approximately 0.33 tons of carbon dioxide. The total power consumption of the system was approximately 59,727.92 kWh. Based on this, the unit hydrogen energy consumption (LCOH) was calculated to be approximately 0.27 Nm³ / kWh, and the unit carbon monoxide energy consumption (LCOC) was approximately 0.23 Nm³ / kWh. All indicators demonstrate that the system has significant advantages in energy conversion efficiency, carbon emission reduction benefits, and operational economy.

[0031] This embodiment fully demonstrates that the system of the present invention successfully solves the stringent requirements of continuous and stable power supply and thermal management in the high-temperature electrolysis process of SOEC by achieving stable output from a methanol fuel cell, green supplementation from photovoltaic energy, and effective recovery of waste heat for power generation, thus overcoming the intermittent nature of renewable energy power generation. The system not only achieves efficient electrolysis and conversion of carbon dioxide but also flexibly adjusts its operating load under different light conditions to maintain efficient hydrogen production, providing a reliable technical path and engineering demonstration for realizing a synergistic "electricity-hydrogen-carbon" cycle in the industrial sector.

[0032] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1.A system for hydrogen production by carbon dioxide electrolysis in cooperation with methanol fuel cell and photovoltaic, comprising a methanol reforming module, a fuel cell module, a gas turbine module, a photovoltaic module and a solid oxide electrolysis cell module, wherein the methanol reforming module is connected to the fuel cell module by a pipeline, the fuel cell module and the methanol reforming module are both connected to the gas turbine module, the fuel cell module, the gas turbine module and the photovoltaic module are all connected to the solid oxide electrolysis cell module by cables, and the solid oxide electrolysis cell module is connected to a carbon dioxide outlet of the gas turbine module by a pipeline. The methanol reforming module is used to convert methanol and water into hydrogen-rich synthesis gas and deliver the hydrogen-rich synthesis gas to the fuel cell module. The fuel cell module is used to convert chemical energy in the hydrogen-rich synthesis gas into electrical energy through an electrochemical reaction. The gas turbine module is used to burn tail gas generated after the operation of the fuel cell module and residual gas generated after the operation of the methanol reforming module, drive a generator to generate supplemental electrical energy, and discharge carbon dioxide-containing mixed gas generated by combustion. The photovoltaic module is used to convert solar energy into electrical energy. The solid oxide electrolysis cell module is used to receive carbon dioxide-containing mixed gas output by the gas turbine module and externally supplemented water vapor, receive electrical energy from the fuel cell module, the gas turbine module and the photovoltaic module, and perform a co-electrolysis reaction on the input carbon dioxide-containing mixed gas and water vapor to generate hydrogen-rich synthesis gas. 2.The system for hydrogen production by carbon dioxide electrolysis in cooperation with methanol fuel cell and photovoltaic according to claim 1, further comprising a compressor module, a hydrogen purification module, a carbon dioxide temporary storage tank, a first separator module, a second separator module, a mixer module and a waste heat recovery power generation device. The compressor module is used to compress air and deliver the compressed air to the cathode of the fuel cell module. The hydrogen purification module is connected between the methanol reforming module and the fuel cell module, used to purify hydrogen in the hydrogen-rich synthesis gas, deliver high-purity hydrogen to the anode of the fuel cell module, and deliver residual gas to the gas turbine module. The carbon dioxide temporary storage tank is used to collect carbon dioxide-containing mixed gas generated during the operation of the gas turbine module. The first separator module is connected to the anode outlet of the solid oxide electrolysis cell module, used to separate and collect oxygen generated by electrolysis. The second separator module is connected to the cathode outlet of the solid oxide electrolysis cell module, used to separate and collect hydrogen and carbon monoxide synthesis gas generated by electrolysis. The mixer module is used to mix electrolyte from the first separator module and the second separator module and then return the electrolyte to the solid oxide electrolysis cell module. The waste heat recovery power generation device is used to recover waste heat in high-temperature product gas from the anode and cathode outlets of the solid oxide electrolysis cell module and flue gas discharged by the gas turbine module, and convert the waste heat into supplemental electrical energy. ​ ​ The electricity output end of the waste heat recovery power generation device is connected to the solid oxide electrolytic cell module through a cable to provide part of the operating power for the solid oxide electrolytic cell module. 3.The system of claim 2, wherein the methanol reforming module is configured to receive the methanol and water, and convert the methanol and water into hydrogen-rich syngas using the waste heat generated by the fuel cell module as a heat source, and the hydrogen-rich syngas is then delivered to the fuel cell module for power generation. 4.The system of claim 3, wherein the fuel cell module is configured to receive the hydrogen-rich syngas from the methanol reforming module, and convert the hydrogen-rich syngas into electricity through electrochemical oxidation reaction at the anode and reduction reaction at the cathode. 5.The system of claim 4, wherein the fuel cell module and the gas turbine module are both connected to the solid oxide electrolytic cell module through a cable, and when the photovoltaic power generation module fails to provide electricity for the solid oxide electrolytic cell module, the fuel cell module and the gas turbine module continuously supply electricity for the solid oxide electrolytic cell module to ensure that it always meets the minimum operating load requirements. 6.The system of claim 5, wherein the solid oxide electrolytic cell module is configured to receive the carbon dioxide generated by the gas turbine module and the externally supplemented carbon dioxide, and water vapor, and convert the carbon dioxide and water into hydrogen-rich syngas under the synergistic effect of electrolysis and high-temperature pyrolysis. The system comprises the following steps: The methanol and water are reformed in the methanol reforming module using the heat energy provided by the fuel cell module to generate hydrogen-rich syngas, and the hydrogen-rich syngas is separated by the hydrogen purification module to obtain high-purity hydrogen and carbon-containing tail gas; The high-purity hydrogen is introduced into the anode of the fuel cell module, and the air compressed by the compressor module is introduced into the cathode of the fuel cell module to generate electricity through electrochemical reaction and generate high-temperature tail gas; The carbon-containing tail gas generated by the hydrogen purification module and the high-temperature tail gas generated by the fuel cell module are introduced into the gas turbine module for combustion to drive the generator to generate supplemental electricity, generate high-temperature flue gas rich in carbon dioxide, and store and buffer the flue gas rich in carbon dioxide in the carbon dioxide temporary storage tank; 7. A method for hydrogen production by carbon dioxide electrolysis in cooperation with a methanol fuel cell and photovoltaic, applied to the hydrogen production system by carbon dioxide electrolysis in cooperation with a methanol fuel cell and photovoltaic according to claim 6, characterized in that, The buffered carbon dioxide-containing gas is mixed with the externally supplemented carbon dioxide and water vapor in the mixer module to form electrolysis raw gas. ​ ​ ​ ​ The electricity generated by the fuel cell module, the gas turbine module and the photovoltaic power generation module is collected and transmitted to the solid oxide electrolysis cell module. When the light is insufficient, the fuel cell module and the gas turbine module provide basic power to maintain the minimum operating load of the solid oxide electrolysis cell module. When the light is sufficient, the photovoltaic power generation module provides main or incremental power to increase the operating load of the solid oxide electrolysis cell module to the high efficiency range. The mixed electrolysis raw gas obtained by the mixer module is introduced into the solid oxide electrolysis cell module. Under the action of electricity and high temperature, the co-electrolysis reaction of carbon dioxide and water vapor is carried out, hydrogen and carbon monoxide mixed synthesis gas is generated at the cathode, and oxygen is generated at the anode. The oxygen generated at the anode of the solid oxide electrolysis cell module is separated and collected by the first separator module. The hydrogen and carbon monoxide mixed synthesis gas generated at the cathode is separated and collected by the second separator module. The waste heat in the high-temperature product gas discharged from the solid oxide electrolysis cell module and the flue gas discharged from the gas turbine module is recovered. The waste heat is converted into supplementary electricity by the waste heat recovery power generation device and fed back to the power supply system of the solid oxide electrolysis cell module.

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