A system for the production of high temperature co-electrolysis syngas

Abstract

The embodiment of the specification discloses a preparation system of high-temperature co-electrolysis synthesis gas, which comprises multiple structural same electric pile-heat box modules integrated in a prying dress assembly, a gas supply system, a quantitative evaporation device, an air supply system and a tail gas treatment system. The gas supply system independently supplies carbon dioxide, nitrogen and hydrogen for each module through a high-pressure gas tank and a gas inlet main pipe; the quantitative evaporation device provides water vapor for each module through an electronic water pump, a high-pressure common rail and an evaporator; the air supply system supplies air for the electric pile cabin and the heat box air flow gap through an air main pipe and an oxygen-enriched air main pipe respectively; the tail gas treatment system processes the output gas through a condenser, a low-pressure tank, a carbon removal device and a compression circuit, and realizes the recycling of unreacted gas. Through the same structure modular design and the public main pipe system, the system can realize flexible expansion from the hundred kilowatt level to the megawatt level, and ensure the efficiency and stability of the synthesis gas preparation process.

Description

Technical Field

[0001] This application relates to the field of high-temperature co-electrolysis technology, and in particular to a system for preparing high-temperature co-electrolysis syngas. Background Technology

[0002] Solid oxide electrolysis (SOEC) high-temperature co-electrolysis technology is a highly efficient electrochemical conversion process capable of simultaneously electrolyzing water vapor and carbon dioxide. This technology leverages the thermodynamic advantages of a high-temperature environment to significantly reduce the electrical energy required for the reaction and can directly produce hydrogen, carbon monoxide, or a mixture thereof (i.e., syngas). Syngas is a key precursor for the production of methanol, Fischer-Tropsch fuels, synthetic ammonia, and other bulk chemicals. Therefore, high-temperature co-electrolysis is considered one of the core pathways to achieve renewable energy storage and carbon dioxide resource utilization.

[0003] Currently, this technology has gradually moved from laboratory research to pilot-scale demonstrations at the kilowatt and even megawatt levels. Companies and research institutions in Europe, the United States, and Japan have launched numerous demonstration projects, such as using megawatt-level SOEC devices to combine captured carbon dioxide with a renewable electricity-driven water electrolysis process to produce methanol. Regarding system scale-up schemes, existing technologies largely draw on the modular experience of solid oxide fuel cells (SOFCs), primarily employing the method of combining multiple independent heatbox units or stack modules on-site to increase total power. While these schemes achieve capacity expansion to some extent, they are essentially still simple aggregations of independent units.

[0004] However, directly transplanting such modular solutions originating from power generation applications to high-temperature co-electrolysis scenarios reveals significant limitations in adaptability. Firstly, existing modular structures are primarily designed for power generation conditions, failing to adequately consider the uniform distribution and dynamic control of the carbon dioxide and water vapor mixture, as well as the corresponding thermal management mechanisms. Secondly, low system-level integration leads to common engineering challenges when scaling to hundreds of kilowatts or larger, including uneven flow distribution among fuel cells, complex thermal coupling management, and inconsistent electrical interfaces, limiting stable system operation and further scaling. Furthermore, the lack of a unified standardized design in existing technologies necessitates extensive customization during system expansion, increasing engineering complexity and cost, and hindering flexible and economical large-scale deployment.

[0005] Therefore, there is an urgent need in this field for a high-temperature co-electrolysis system architecture that is highly integrated and inherently scalable for power levels of hundreds of kilowatts and above, in order to address the shortcomings of existing technologies in terms of engineering scale-up, system integration and standardization. Utility Model Content

[0006] This specification provides a high-temperature co-electrolysis syngas preparation system to solve at least one of the technical problems mentioned above.

[0007] To solve the above-mentioned technical problems, the embodiments in this specification are implemented as follows:

[0008] According to a first aspect of the present invention, a high-temperature co-electrolysis syngas preparation system is provided, comprising:

[0009] Skid-mounted components, multiple fuel cell stack-heatbox modules, gas supply system, quantitative evaporation unit, air supply system, exhaust gas treatment system, and syngas output main pipeline;

[0010] in,

[0011] The multiple identical fuel cell stack-thermal box modules are integrated within the skid-mounted assembly. Each fuel cell stack-thermal box module includes a fuel cell compartment and a thermal box that covers the outside of the fuel cell compartment. An airflow gap is formed between the thermal box and the fuel cell compartment.

[0012] The gas supply system is integrated within the skid-mounted assembly and includes a high-pressure gas tank, an inlet main pipe connecting the high-pressure gas tank, and a first gas distribution branch and a second gas distribution branch independently provided for each fuel cell stack-heatbox module. The inlet main pipe includes a carbon dioxide main pipe, a nitrogen main pipe, and a hydrogen main pipe. The first gas distribution branch is connected one-to-one to the carbon dioxide / nitrogen inlet of each fuel cell stack-heatbox module, and the second gas distribution branch is connected one-to-one to the hydrogen inlet of each fuel cell stack-heatbox module.

[0013] The quantitative evaporation device is integrated into the skid-mounted assembly and includes an electronic water pump, a high-pressure common rail, and an evaporator. The input end of the electronic water pump is connected to the ultrapure water main pipe, the output end of the electronic water pump is connected to the high-pressure common rail, the output end of the high-pressure common rail is connected to the evaporator, and the output end of the evaporator is connected to the steam inlet of each fuel cell stack-heatbox module through steam branch pipes.

[0014] The air supply system is integrated within the skid-mounted assembly and includes an air main pipe, an oxygen-enriched air main pipe, and an air branch independently provided for each fuel cell stack-heatbox module; the input end of the air branch is connected to the air main pipe, and the output end of the air branch is connected to the fuel cell stack compartment; the oxygen-enriched air main pipe is connected to the airflow gap of each heatbox through oxygen-enriched air branch pipes.

[0015] The exhaust gas treatment system includes a condenser, a low-pressure tank, a decarbonization device, a first compression circuit, and a second compression circuit. The input end of the condenser is connected to the output gas outlet of each fuel cell stack-heatbox module via output gas branch pipes, and the output end of the condenser is connected to the low-pressure tank. The outlet of the low-pressure tank is connected to the input end of the first compression circuit and the input end of the decarbonization device via three-way valves. The decarbonization device has a carbon dioxide output end and a reducing gas output end. The carbon dioxide output end is connected to the main carbon dioxide pipeline via a carbon dioxide circulation pipeline, and the reducing gas output end is connected to the main hydrogen pipeline via a reducing gas circulation pipeline. The first compression circuit includes a first compressor, the output end of which is connected to the high-pressure gas tank. The second compression circuit includes a second compressor, the input end of which is connected to the carbon dioxide output end and the reducing gas output end of the decarbonization device, and the output end of the second compressor is connected to the main carbon dioxide pipeline and the main hydrogen pipeline, respectively.

[0016] The syngas output main pipe is connected to the reducing gas output terminal of the carbon removal device;

[0017] The main intake pipe, ultrapure water main pipe, air main pipe, oxygen-enriched air main pipe, and syngas output main pipe together constitute a common main pipeline system.

[0018] In some optional implementations, the first gas distribution branch is composed of gas rail group A; each of the gas rail group A is connected in series with a first shut-off valve, a first flow meter, a first fan and a first nozzle, the first input end of the first shut-off valve is connected to the carbon dioxide main pipe and the second input end is connected to the nitrogen main pipe, and the output end of the first nozzle is connected to the carbon dioxide and nitrogen inlet of the corresponding fuel cell stack-heatbox module.

[0019] The second gas distribution branch is composed of gas rail group B; each of the gas rail group B is connected in series with a second shut-off valve, a second flow meter, a second fan and a second nozzle. The input end of the second shut-off valve is connected to the hydrogen main pipe, and the output end of the second nozzle is connected to the hydrogen inlet end of the corresponding fuel cell stack-heatbox module.

[0020] Each of the air branch lines is connected in series with a third fan and a third flow meter. The input end of the third fan is connected to the main air pipe, and the output end of the third flow meter is connected to the air inlet of the fuel cell stack compartment.

[0021] In some alternative implementations, both the first nozzle and the second nozzle are sonic nozzles that operate based on the critical flow principle, and the flow rate of the sonic nozzle is only related to the pressure and temperature of the upstream gas.

[0022] In some alternative embodiments, a heating unit is provided inside the hot box;

[0023] The high-pressure gas tank includes a shared high-pressure gas tank, the outlet of which is connected to the carbon dioxide main pipeline and the nitrogen main pipeline.

[0024] In some optional embodiments, the skid-mounted assembly is divided into a fuel cell module area, a quantitative evaporation area, a gas supply area, and an exhaust gas treatment area; the multiple fuel cell-heatbox modules are arranged in the fuel cell module area, the quantitative evaporation device is located in the quantitative evaporation area, the gas supply system is located in the gas supply area, and the exhaust gas treatment system is located in the exhaust gas treatment area.

[0025] The number of the fuel cell stack-thermal box modules is three or more.

[0026] In some optional embodiments, each of the gas rail group A, gas rail group B, and the output end of the evaporator is provided with an independent shut-off valve on the connecting pipeline between the stack-heatbox module and each of the fuel cell stack modules.

[0027] In some alternative implementations, the configuration of the independent shut-off valves enables the system to selectively establish feed atmospheres of pure water vapor, pure carbon dioxide, or a mixture of water vapor and carbon dioxide for different fuel cell stack-thermal box modules.

[0028] In some alternative embodiments, both the carbon dioxide circulation line and the reducing gas circulation line are equipped with check valves.

[0029] In some alternative implementations, the condenser cools the output gas from the fuel cell-heatbox module to 80 to 90 degrees Celsius to remove unreacted water vapor from the output gas.

[0030] The technical solution of this application has several significant technical advantages, as detailed below:

[0031] This application's technical solution integrates multiple identical fuel cell stack-heatbox modules into a unified skid-mounted assembly and constructs a common main pipeline system consisting of an intake, ultrapure water, air, oxygen-enriched air, and syngas output main pipeline. This enables standardized integration and coordinated operation of multiple isomorphic electrolysis units, overcoming the shortcomings of traditional modular solutions in terms of low system integration and inconsistent interfaces during expansion. Based on the system architecture of isomorphic modules and a unified main pipeline, combined with independently set gas distribution branches, quantitative evaporation devices, and tail gas circulation pipelines for each module, precise distribution of the reaction medium and efficient product recovery are achieved through centralized supply and distributed control. This highly integrated and modular collaborative design enables flexible expansion and stable operation at power levels from hundreds of kilowatts to megawatts. It solves the problems of expansion difficulties, uneven gas distribution, and insufficient tail gas utilization caused by structural heterogeneity in existing technologies, improving the economy and reliability of large-scale system applications. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the overall architecture of the high-temperature co-electrolysis syngas preparation system provided in this application;

[0034] Figure 2 This is a modular layout diagram of the interior of the skid-mounted assembly;

[0035] Figure 3 A detailed structural diagram of the gas supply and exhaust gas recirculation. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of one or more embodiments of this specification clearer, the technical solutions of one or more embodiments of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of one or more embodiments of this specification.

[0037] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another.

[0038] Figure 1 A schematic diagram of the overall architecture of the high-temperature co-electrolysis syngas preparation system provided in this application; Figure 2 This is a modular layout diagram of the interior of the skid-mounted assembly; Figure 3 This is a detailed structural diagram of the gas supply and exhaust gas recirculation. The following description, in conjunction with the accompanying drawings, explains the high-temperature co-electrolysis syngas preparation system provided by this application. Figure 1 and Figure 2 As shown, the high-temperature co-electrolysis syngas preparation system provided in this application includes:

[0039] Skid-mounted components, multiple fuel cell stack-heatbox modules, gas supply system, quantitative evaporation unit, air supply system, exhaust gas treatment system, and syngas output main pipeline;

[0040] in,

[0041] The multiple identical fuel cell stack-thermal box modules are integrated within the skid-mounted assembly. Each fuel cell stack-thermal box module includes a fuel cell compartment and a thermal box that covers the outside of the fuel cell compartment. An airflow gap is formed between the thermal box and the fuel cell compartment.

[0042] The gas supply system is integrated within the skid-mounted assembly and includes a high-pressure gas tank, an inlet main pipe connecting the high-pressure gas tank, and a first gas distribution branch and a second gas distribution branch independently provided for each fuel cell stack-heatbox module. The inlet main pipe includes a carbon dioxide main pipe, a nitrogen main pipe, and a hydrogen main pipe. The first gas distribution branch is connected one-to-one to the carbon dioxide / nitrogen inlet of each fuel cell stack-heatbox module, and the second gas distribution branch is connected one-to-one to the hydrogen inlet of each fuel cell stack-heatbox module.

[0043] The quantitative evaporation device is integrated into the skid-mounted assembly and includes an electronic water pump, a high-pressure common rail, and an evaporator. The input end of the electronic water pump is connected to the ultrapure water main pipe, the output end of the electronic water pump is connected to the high-pressure common rail, the output end of the high-pressure common rail is connected to the evaporator, and the output end of the evaporator is connected to the steam inlet of each fuel cell stack-heatbox module through steam branch pipes.

[0044] The air supply system is integrated within the skid-mounted assembly and includes an air main pipe, an oxygen-enriched air main pipe, and an air branch independently provided for each fuel cell stack-heatbox module; the input end of the air branch is connected to the air main pipe, and the output end of the air branch is connected to the fuel cell stack compartment; the oxygen-enriched air main pipe is connected to the airflow gap of each heatbox through oxygen-enriched air branch pipes.

[0045] The exhaust gas treatment system includes a condenser, a low-pressure tank, a decarbonization device, a first compression circuit, and a second compression circuit. The input end of the condenser is connected to the output gas outlet of each fuel cell stack-heatbox module via output gas branch pipes, and the output end of the condenser is connected to the low-pressure tank. The outlet of the low-pressure tank is connected to the input end of the first compression circuit and the input end of the decarbonization device via three-way valves. The decarbonization device has a carbon dioxide output end and a reducing gas output end. The carbon dioxide output end is connected to the main carbon dioxide pipeline via a carbon dioxide circulation pipeline, and the reducing gas output end is connected to the main hydrogen pipeline via a reducing gas circulation pipeline. The first compression circuit includes a first compressor, the output end of which is connected to the high-pressure gas tank. The second compression circuit includes a second compressor, the input end of which is connected to the carbon dioxide output end and the reducing gas output end of the decarbonization device, and the output end of the second compressor is connected to the main carbon dioxide pipeline and the main hydrogen pipeline, respectively.

[0046] The syngas output main pipe is connected to the reducing gas output terminal of the carbon removal device;

[0047] The main intake pipe, ultrapure water main pipe, air main pipe, oxygen-enriched air main pipe, and syngas output main pipe together constitute a common main pipeline system.

[0048] The following description, in conjunction with the accompanying drawings, illustrates a possible configuration of the above-mentioned technical solution in a practical scenario. The overall architecture and modular layout of this high-temperature co-electrolysis syngas preparation system are shown below. Figure 1 and Figure 2 As shown. This system employs a highly integrated skid-mounted design, connecting multiple isomorphic fuel cell stack-thermal box modules via a common trunk piping system, achieving efficient, stable, and scalable operation. The skid-mounted assembly serves as the integrated carrier for the entire system, housing all functional modules and enabling a compact, standardized layout that facilitates transportation, installation, and on-site deployment. From Figure 2 As can be seen, the skid-mounted assembly forms a well-organized installation space, with each component arranged according to functional zones. This ensures optimized design of gas flow paths, circuits, and heat exchange paths, while also reserving reasonable operating space for maintenance of each system, guaranteeing the overall feasibility of the system's engineering applications. Multiple identical fuel cell stack-heatbox modules are integrated in parallel within the skid-mounted assembly, forming the system's electrolysis reaction unit. Each fuel cell stack-heatbox module includes a fuel cell compartment and a heatbox. The heatbox is fitted over the fuel cell compartment in an enclosed structure, with an annular airflow gap formed between the inner wall of the heatbox and the outer wall of the fuel cell compartment. This structure allows for airflow from... Figure 2The relative positions of the intermediate heating box and the fuel cell stack compartment are observable. The fuel cell stack compartment houses the solid oxide electrolytic reactor required for high-temperature co-electrolysis, which supports the co-electrolysis reaction of H2O and CO2. The heating box contains a heating unit that provides a high-temperature reaction environment of 700℃ to 900℃ for the fuel cell stack compartment, ensuring the thermodynamic conditions of the electrolysis reaction. At the same time, the enclosure structure of the heating box reduces heat loss and improves the system's thermal efficiency.

[0049] The gas supply system, integrated within the skid-mounted assembly, provides a stable and accurate supply of reaction gases to each fuel cell stack-thermal chamber module. It includes a high-pressure gas tank, a main inlet pipe, and a first and second gas distribution branch independently configured for each fuel cell stack-thermal chamber module. The main inlet pipe consists of a carbon dioxide main pipe, a nitrogen main pipe, and a hydrogen main pipe; the input ends of all three main pipes are connected to the high-pressure gas tank. Figure 1The connection between the medium- and high-pressure gas tanks and each main gas inlet pipe clarifies this structure. This design enables centralized storage and unified supply of reaction gases. The carbon dioxide main pipe is used to transport CO2, the raw material for co-electrolysis reaction; the nitrogen main pipe is used for purging protection gas during system startup / shutdown; and the hydrogen main pipe is used to provide reducing protection gas and reaction auxiliary gas. The first gas distribution branch is connected one-to-one with the carbon dioxide / nitrogen inlet of each fuel cell stack-heatbox module, allowing selective delivery of CO2 or nitrogen to the corresponding module to meet the gas requirements of different operating stages. The second gas distribution branch is connected one-to-one with the hydrogen inlet of each fuel cell stack-heatbox module, specifically responsible for supplying hydrogen to each module to ensure the reducing operating environment of the fuel cell stack. Through the independent distribution branch design, independent control of the gas supply to each fuel cell stack-heatbox module is achieved, ensuring the consistency of operating conditions when multiple modules are running in parallel. The quantitative evaporation unit is also integrated into the skid-mounted assembly. It is used to convert ultrapure water into high-temperature steam and precisely supply it to each fuel cell stack-heatbox module. It includes an electric water pump, a high-pressure common rail, and an evaporator. The three are connected in series to form a complete steam preparation chain. The input end of the electric water pump is connected to the ultrapure water main pipe to draw ultrapure water raw material. The output end of the electric water pump is connected to the high-pressure common rail, which can stably maintain the ultrapure water pressure at 1MPa, providing a stable pressure basis for subsequent quantitative evaporation. The output end of the high-pressure common rail is connected to the evaporator. The evaporator heats the high-pressure ultrapure water to an evaporation state through a built-in heating element, converting it into high-temperature steam. The output end of the evaporator is connected to the steam inlet of each fuel cell stack-heatbox module through multiple steam branch pipes, thereby realizing the on-demand distribution of steam. The air supply system, integrated within the skid-mounted assembly, provides gas for the fuel cell reactor and thermal management of the hotbox. It includes a main air pipe, an oxygen-enriched air main pipe, and independent air branches for each fuel cell-hotbox module. The inputs of these air branches are connected to the main air pipe, and their outputs are connected to the air inlets of each fuel cell compartment. These air branches supply air to the fuel cell compartments, providing the necessary oxygen partial pressure environment for the electrolysis reaction and participating in the fuel cell's thermal balance regulation. The oxygen-enriched air main pipe is connected to the airflow gaps of each hotbox via multiple oxygen-enriched air branches. The oxygen-enriched air flows within these gaps, helping to maintain temperature stability in the hotboxes and carrying away excess heat transferred from the fuel cell compartments to the hotboxes, thus achieving module thermal management.

[0050] The exhaust gas treatment system is used to treat, separate, and recycle the reaction products of the fuel cell stack-heatbox module. It includes a condenser, a low-pressure tank, a decarbonization device, a first compression loop, and a second compression loop. These components are connected sequentially via pipelines to form a closed-loop treatment system. The condenser's input is connected to the output gas outlets of each fuel cell stack-heatbox module via multiple output gas branch pipes. After entering the condenser, the output gas is cooled to 80℃~90℃, removing unreacted water vapor and achieving gas-liquid separation. The condenser's output is connected to the low-pressure tank, where the cooled and dehydrated gas is temporarily stored. A three-way valve is installed at the low-pressure tank's outlet to switch the flow direction of the gas. During system startup, the gas is returned to the high-pressure tank via the first compression loop, which includes a first compressor. The compressor's input is connected to the three-way valve, and its output is connected to the high-pressure tank. During normal electrolysis, the gas is introduced into the decarbonization device, which is equipped with carbon dioxide. The output end and reducing gas output end (mainly a mixture of H2 and CO) enable efficient separation of unreacted CO2 and reducing gas. The carbon dioxide output end is connected to the main carbon dioxide pipeline via a carbon dioxide circulation pipeline, and the separated unreacted CO2 flows back to the gas supply system to participate in the reaction again. The reducing gas output end is connected to the main hydrogen pipeline via a reducing gas circulation pipeline, and part of the reducing gas is recycled. The second compression circuit includes a second compressor. The input end of the second compressor is connected to the carbon dioxide output end and the reducing gas output end of the decarbonization unit, respectively, and the output end is connected to the main carbon dioxide pipeline and the main hydrogen pipeline, respectively, providing power support for the reflux of the separated gas and ensuring the stable operation of the circulation pipeline. The input end of the syngas output main pipeline is connected to the reducing gas output end of the decarbonization unit. After separation by the decarbonization unit, the unrecycled reducing gas, i.e., the target syngas (containing H2 and CO), is output through this main pipeline to supply downstream processes such as methanol synthesis and Fischer-Tropsch synthesis. This output flow direction is from... Figure 1 The layout of the syngas main pipeline is clearly visible. The main inlet pipeline (including carbon dioxide, nitrogen, and hydrogen pipelines), ultrapure water pipeline, air pipeline, oxygen-enriched air pipeline, and syngas outlet pipeline together form a common main pipeline system. This system runs through the entire skid-mounted assembly, providing a unified fluid transmission channel for each functional module. It ensures centralized supply and output of gases and water vapor, while also guaranteeing consistent media distribution during parallel operation of multiple modules. This system serves as a supporting structure for system scalability. Figure 1 The layout and connection of the main pipelines further demonstrate the system's integrative role.

[0051] This system achieves a high-temperature co-electrolysis reaction of H2O and CO2 through the integrated design and collaborative operation of the above-mentioned components. It can stably produce syngas containing H2 and CO, while improving the utilization rate of raw materials through tail gas recycling. The modular skid-mounted design ensures the system's scalability.

[0052] This application's technical solution integrates multiple identical fuel cell stack-heatbox modules into a unified skid-mounted assembly and constructs a common main pipeline system consisting of an intake, ultrapure water, air, oxygen-enriched air, and syngas output main pipeline. This enables standardized integration and coordinated operation of multiple isomorphic electrolysis units, overcoming the shortcomings of traditional modular solutions in terms of low system integration and inconsistent interfaces during expansion. Based on the system architecture of isomorphic modules and a unified main pipeline, combined with independently set gas distribution branches, quantitative evaporation devices, and tail gas circulation pipelines for each module, precise distribution of the reaction medium and efficient product recovery are achieved through centralized supply and distributed control. This highly integrated and modular collaborative design enables flexible expansion and stable operation at power levels from hundreds of kilowatts to megawatts. It solves the problems of expansion difficulties, uneven gas distribution, and insufficient tail gas utilization caused by structural heterogeneity in existing technologies, improving the economy and reliability of large-scale system applications.

[0053] Based on the technical solutions described above, this specification also provides some specific implementation schemes, which are described below.

[0054] In an optional embodiment, the first gas distribution branch is composed of gas rail A group; each of the gas rail A group is connected in series with a first shut-off valve, a first flow meter, a first fan and a first nozzle. The first input end of the first shut-off valve is connected to the carbon dioxide main pipe and the second input end is connected to the nitrogen main pipe. The output end of the first nozzle is connected to the carbon dioxide and nitrogen inlet of the corresponding fuel cell stack-heatbox module.

[0055] The second gas distribution branch is composed of gas rail group B; each of the gas rail group B is connected in series with a second shut-off valve, a second flow meter, a second fan and a second nozzle. The input end of the second shut-off valve is connected to the hydrogen main pipe, and the output end of the second nozzle is connected to the hydrogen inlet end of the corresponding fuel cell stack-heatbox module.

[0056] Each of the air branch lines is connected in series with a third fan and a third flow meter. The input end of the third fan is connected to the main air pipe, and the output end of the third flow meter is connected to the air inlet of the fuel cell stack compartment.

[0057] The following is combined Figure 3 The contents of the gas distribution branch and the air branch in this embodiment are described. For example... Figure 3 As shown, Figure 3The structure and connection relationships of the first gas distribution branch, the second gas distribution branch, and the air branch are clearly illustrated. The first gas distribution branch is composed of gas rail group A, which includes multiple parallel branches (such as...). Figure 3 The air rails A1, A2, and A3 are indicated in the diagram, and each branch line is connected in series with a first shut-off valve, a first flow meter, a first fan, and a first nozzle in a fixed order. Specifically, Figure 3 The components designated "Fan 1" and "Fan 2" are the first fans on different branches of gas rail group A. Each fan is connected in series with the first shut-off valve, the first flow meter, and the first nozzle of its respective branch. The first shut-off valve has two input terminals: one connected to the carbon dioxide main pipe and the other connected to the nitrogen main pipe, allowing for switching between carbon dioxide and nitrogen supply depending on the system's operating phase. The output terminal of the first nozzle is connected to the carbon dioxide or nitrogen inlet of the corresponding fuel cell stack-heatbox module, enabling independent control of the gas supply for each individual path.

[0058] Similarly, the second gas distribution branch is composed of gas rail group B, which also contains multiple parallel branches (such as...). Figure 3 The air rails B1, B2, and B3 are marked in the middle. Each branch is connected in series with a second shut-off valve, a second flow meter, a second fan, and a second nozzle. Figure 3 The fans connected in series on each branch of the gas rail B group are the second fans, distinct from the first fans of the gas rail A group; the second shut-off valve has only one input end, which is connected to the main hydrogen pipeline and is dedicated to transporting hydrogen; the output end of the second nozzle is connected to the hydrogen inlet of the corresponding fuel cell stack-heatbox module, ensuring the stability and independence of the hydrogen supply. Furthermore, Figure 3 The diagram also illustrates the connection structure of the air branch circuits, with each air branch circuit connected in series with a third fan and a third flow meter. Figure 3 The component that won the bid, designated as "Fan 3," is the third fan on the air branch line. The input end of the third fan is connected to the main air pipe, while the output end of the third flow meter is connected to the air intake end of the fuel cell stack compartment. By adjusting the air intake volume through the third fan and monitoring the flow rate through the third flow meter, an independent air supply and control path is formed for each fuel cell stack-heatbox module, meeting the oxygen partial pressure requirements of the electrolysis reaction.

[0059] In an optional embodiment, both the first nozzle and the second nozzle are sonic nozzles that operate based on the critical flow principle, and the flow rate of the sonic nozzle is only related to the pressure and temperature of the upstream gas.

[0060] In an optional embodiment, the hot box is equipped with a heating unit; the high-pressure gas tank includes a common high-pressure gas tank, the outlet pipeline of which is connected to the carbon dioxide main pipe and the nitrogen main pipe.

[0061] In this embodiment, each fuel cell stack-heatbox module has a dedicated heating unit inside its heatbox. This heating unit maintains the system at a high temperature and, during startup, accurately controls the temperature of the fuel cell stack from room temperature to the operating temperature range of 700 to 900 degrees Celsius. During normal operation, it continuously compensates for system heat loss, ensuring a uniform and stable temperature field across all modules. This modular, independent heating design allows for accurate thermal management of each fuel cell stack, creating the necessary thermodynamic conditions for the high-temperature co-electrolysis reaction and ensuring temperature consistency and reaction stability under different operating conditions.

[0062] Meanwhile, in this embodiment, an integrated gas source configuration scheme is adopted in the gas supply system. The system is equipped with a shared high-pressure gas tank (i.e., in...). Figure 1 The high-pressure tank (located in the lower left corner and at the top) is connected to both the carbon dioxide and nitrogen main pipelines via branch lines. This design fully utilizes the complementary nature of nitrogen and carbon dioxide usage during system operation; nitrogen is primarily used for start-up purging and shutdown protection phases, while carbon dioxide is dedicated to the normal electrolysis reaction phase. Through coordinated control of the gas circuit valves, the supply of the two gases can be switched on demand.

[0063] In an optional embodiment, the skid-mounted assembly is divided into a fuel cell module area, a quantitative evaporation area, a gas supply area, and an exhaust gas treatment area; the multiple fuel cell-heatbox modules are arranged in the fuel cell module area, the quantitative evaporation device is located in the quantitative evaporation area, the gas supply system is located in the gas supply area, and the exhaust gas treatment system is located in the exhaust gas treatment area.

[0064] The number of the fuel cell stack-thermal box modules is three or more.

[0065] In this embodiment, the internal structural layout of the skid-mounted assembly has been specifically optimized. The interior of the skid-mounted assembly is divided into four relatively independent and functionally defined working areas: the fuel cell stack module area, the quantitative evaporation area, the gas supply area, and the exhaust gas treatment area. In this specific layout, multiple identical fuel cell stack-heatbox modules are arranged side-by-side in the fuel cell stack module area, forming the core reaction unit of the system. The quantitative evaporation device is independently located in the quantitative evaporation area. This device achieves precise preparation and supply of water vapor through a combination of an electric water pump, a high-pressure common rail, and an evaporator. The gas supply system is centrally located in the gas supply area, including a high-pressure gas tank and related main inlet pipes and distribution branches. The exhaust gas treatment system is entirely located in the exhaust gas treatment area, including a condenser, a low-pressure tank, a carbon removal device, and a compression circuit, responsible for the treatment and recovery of the produced gas.

[0066] The fuel cell stack-heatbox module is configured with three or more modules. A three-module configuration can meet the basic requirements for hundreds of kilowatts of power output and provide the infrastructure for system power expansion. When further increasing system capacity is needed, simply increase the number of homogeneous modules in the fuel cell stack module area and correspondingly expand the capacity of the common trunk piping system to achieve a smooth expansion to megawatt-level scale. This modular, partitioned layout in this embodiment not only ensures a rational path for internal material and energy flow but also improves equipment maintainability and engineering implementation efficiency.

[0067] Through the above-described zoning and integration design, each functional system maintains relative independence in space while being closely connected through a common main pipeline system. The gas supply system delivers reactant gases to the fuel cell module area via the main pipeline, the metered evaporation unit supplies water vapor via a dedicated pipeline, and the exhaust gas treatment system processes the output gases from each module via collection pipelines. This layout effectively shortens the connection distance between functional units and reduces pipeline pressure loss and heat dissipation.

[0068] In an optional embodiment, each of the gas rail group A, gas rail group B, and the output end of the evaporator is equipped with an independent shut-off valve on the connecting pipeline between the gas rail group A, the gas rail group B, and each of the fuel cell stack-heatbox modules.

[0069] In this embodiment, independent shut-off valves are installed on the gas rail group A, gas rail group B, and the connecting pipelines between the evaporator output and each fuel cell stack-heatbox module. Specifically, in the gas supply system, the first gas distribution branch, i.e., gas rail group A, which is independently configured for each fuel cell stack-heatbox module, has an independent shut-off valve installed on the pipeline connecting to the carbon dioxide and nitrogen inlet of the corresponding module. Similarly, the second gas distribution branch, i.e., gas rail group B, also has an independent shut-off valve installed on the pipeline connecting to the hydrogen inlet of the corresponding module. In the quantitative evaporation system, each steam branch pipe leading from the evaporator output and connecting to the steam inlet of each fuel cell stack-heatbox module is also equipped with a corresponding independent shut-off valve. These independent shut-off valves enable the system controller to independently control the opening or closing of the carbon dioxide or nitrogen flow, hydrogen flow, and steam flow supplied to any specific fuel cell stack-heatbox module.

[0070] In this embodiment, the technical solution is based on the ability to independently control the medium supply to each module, which enables flexible configuration of the operating mode. For example, it is possible to selectively supply water vapor to some modules for water electrolysis, while supplying carbon dioxide to other modules for dry electrolysis. This allows for flexible adjustment of the ratio of hydrogen to carbon monoxide in the final syngas produced at the system level, meeting the specific requirements of different downstream chemical processes for syngas composition. At the same time, it avoids the operational risks and material stress problems caused by complex atmosphere switching within a single fuel cell stack.

[0071] In an optional embodiment, the configuration of the independent shut-off valve enables the system to selectively establish a feed atmosphere of pure water vapor, pure carbon dioxide, or a mixture of water vapor and carbon dioxide for different fuel cell stack-heatbox modules.

[0072] In this embodiment, by controlling the opening and closing combinations of the independent shut-off valves on the carbon dioxide / nitrogen branch and the steam output branch of the evaporator in gas rail group A, three different feed atmospheres can be established for each fuel cell stack-heatbox module. Specifically, when only the steam branch shut-off valve is opened and the carbon dioxide branch shut-off valve is closed, the module establishes a pure steam feed atmosphere to generate hydrogen through water electrolysis; when only the carbon dioxide branch shut-off valve is opened and the steam branch shut-off valve is closed, the module establishes a pure carbon dioxide feed atmosphere to generate carbon monoxide through dry electrolysis; when both the steam and carbon dioxide branch shut-off valves are opened simultaneously, a feed atmosphere of a mixture of steam and carbon dioxide is established to generate both hydrogen and carbon monoxide through co-electrolysis. In this embodiment, the independent control mechanism allows multiple parallel-running modules to operate in different electrolysis modes. For example, the three modules in the system can be configured such that two modules run pure water electrolysis and one module runs pure carbon dioxide electrolysis, thereby accurately controlling the molar ratio of hydrogen to carbon monoxide in the final syngas product at the system level, so that it stably reaches the 2:1 ratio required for downstream methanol synthesis or other specific ratios required by chemical processes.

[0073] In an optional embodiment, both the carbon dioxide circulation pipeline and the reducing gas circulation pipeline are equipped with one-way valves.

[0074] In this embodiment, one-way valves are installed on both the carbon dioxide circulation pipeline connecting the carbon dioxide output end of the decarbonization device to the carbon dioxide main pipeline and the reducing gas circulation pipeline connecting the reducing gas output end of the decarbonization device to the hydrogen main pipeline. The configuration of these one-way valves ensures that the unreacted carbon dioxide that is separated and recovered can only flow from the decarbonization device to the carbon dioxide main pipeline for recycling, while the separated reducing gas can only flow from the decarbonization device to the hydrogen main pipeline to participate in recirculation. This effectively prevents the gas in the high-pressure main pipeline from flowing back to the low-pressure side decarbonization device or from crosstalk between different gas circuits when the system pressure fluctuates.

[0075] In an optional embodiment, the condenser cools the output gas of the fuel cell stack-heatbox module to 80 to 90 degrees Celsius to remove unreacted water vapor from the output gas.

[0076] Based on the foregoing technical solutions, this utility model also provides a method for preparing high-temperature co-electrolysis syngas, applicable to any of the high-temperature co-electrolysis syngas preparation systems described above, comprising the following steps:

[0077] Reactant gases and water vapor are independently supplied to multiple identical fuel cell stack-thermal box modules. Specifically, carbon dioxide or nitrogen is independently supplied to the carbon dioxide or nitrogen inlet of each fuel cell stack-thermal box module, hydrogen is independently supplied to the hydrogen inlet, and water vapor is independently supplied to the water vapor inlet.

[0078] Air is introduced into the fuel cell compartment of each fuel cell stack-thermal box module, and oxygen-enriched air is introduced into the airflow gap of the thermal box of each fuel cell stack-thermal box module.

[0079] A high-temperature co-electrolysis reaction is carried out in the fuel cell-thermal box module to generate an output gas containing hydrogen and carbon monoxide;

[0080] The produced gas from each fuel cell stack-thermal box module is cooled to 80 to 90 degrees Celsius by a condenser. After cooling and dehydration, gas-liquid separation is performed to obtain the gas to be processed.

[0081] According to the system operation stage, the gas to be processed is processed accordingly, including:

[0082] During the system startup phase, the gas to be processed is returned to the high-pressure gas tank via the first compressor;

[0083] During the normal electrolysis phase of the system, the gas to be treated is passed into a carbon removal device for separation to obtain unreacted carbon dioxide and reducing gas. The unreacted carbon dioxide obtained is returned to the carbon dioxide main pipeline for recycling through a second compressor. A portion of the reducing gas is returned to the hydrogen main pipeline for recycling through a second compressor, and the remaining reducing gas is output as a synthesis gas product.

[0084] In this technical solution, a highly independent media supply system is first used to establish a precise and controllable reaction environment for each fuel cell stack-thermal box module. In the gas supply stage, the system accurately controls the gas flow rate of each module based on the critical flow principle, specifically through sonic nozzles for metering. The mass flow rate calculation formula is as follows:

[0085]

[0086] in For mass flow rate, C d Let γ be the flow coefficient, A be the throat area, P0 and T0 be the upstream gas pressure and temperature, respectively, γ be the specific heat ratio, and R be the gas constant. This formula shows that when the pressure difference across the nozzle reaches a critical state, the flow rate is only related to the upstream parameters, thus ensuring a stable gas supply for each module under different operating conditions. Simultaneously, the quantitative evaporation device maintains a 1MPa water pressure via an electronic water pump, working in conjunction with the atomizing nozzle to achieve precise metering of water vapor, forming a complete independent supply system for the gas and steam phases.

[0087] During the reaction phase, each fuel cell stack-heatbox module undergoes high-temperature co-electrolysis under unified and coordinated operating conditions. Carbon dioxide and water vapor are simultaneously introduced into the fuel cell stack compartment within a temperature range of 700-900℃ to co-electrolyze, generating a product gas containing hydrogen and carbon monoxide. Simultaneously, the system achieves thermal management through two independent gas paths: air is introduced into the fuel cell stack compartment to maintain an appropriate oxygen partial pressure, while oxygen-enriched air is introduced into the gas flow gaps of the heatbox, utilizing its convective heat transfer characteristics to maintain a uniform and stable temperature field within the heatbox. This zoned gas supply design allows each module to meet both the gas phase requirements of the electrolysis reaction and achieve accurate thermal balance control, creating the necessary conditions for efficient and stable co-electrolysis.

[0088] The treatment of the produced gas employs a differentiated strategy based on the system's operational phase. All produced gas from each module is first cooled to 80-90°C by a condenser to remove unreacted water vapor before undergoing gas-liquid separation. During system startup, the gas to be treated is directly returned to the high-pressure gas tank via the first compressor, achieving gas circulation and preheating within the system. Upon entering the normal electrolysis phase, the gas is introduced into a decarbonization unit for component separation. Unreacted carbon dioxide is returned to the carbon dioxide main pipeline via the second compressor, while some reducing gases (H2+CO) are returned to the hydrogen main pipeline, and the remainder is output as syngas. This dynamic treatment strategy based on operational phases ensures the stability of the startup process and enables efficient recycling of raw materials during normal operation, thereby improving the overall energy efficiency of the system.

[0089] Those skilled in the art will understand that the modules in the apparatus of the embodiments can be distributed in the apparatus of the embodiments as described in the embodiments, or they can be located in one or more devices different from this embodiment with corresponding changes. The modules of the above embodiments can be combined into one module, or they can be further divided into multiple sub-modules.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A system for preparing high-temperature co-electrolysis syngas, characterized in that, include: Skid-mounted components, multiple fuel cell stack-heatbox modules, gas supply system, metered evaporation unit, air supply system, exhaust gas treatment system, and syngas output main pipeline; among which, The multiple identical fuel cell stack-thermal box modules are integrated within the skid-mounted assembly. Each fuel cell stack-thermal box module includes a fuel cell compartment and a thermal box that covers the outside of the fuel cell compartment. An airflow gap is formed between the thermal box and the fuel cell compartment. The gas supply system is integrated within the skid-mounted assembly and includes a high-pressure gas tank, an inlet main pipe connecting the high-pressure gas tank, and a first gas distribution branch and a second gas distribution branch independently provided for each fuel cell stack-heatbox module. The inlet main pipe includes a carbon dioxide main pipe, a nitrogen main pipe, and a hydrogen main pipe. The first gas distribution branch is connected one-to-one to the carbon dioxide / nitrogen inlet of each fuel cell stack-heatbox module, and the second gas distribution branch is connected one-to-one to the hydrogen inlet of each fuel cell stack-heatbox module. The quantitative evaporation device is integrated into the skid-mounted assembly and includes an electronic water pump, a high-pressure common rail, and an evaporator. The input end of the electronic water pump is connected to the ultrapure water main pipe, the output end of the electronic water pump is connected to the high-pressure common rail, the output end of the high-pressure common rail is connected to the evaporator, and the output end of the evaporator is connected to the steam inlet of each fuel cell stack-heatbox module through steam branch pipes. The air supply system is integrated within the skid-mounted assembly and includes an air main pipe, an oxygen-enriched air main pipe, and an air branch independently provided for each fuel cell stack-heatbox module; the input end of the air branch is connected to the air main pipe, and the output end of the air branch is connected to the fuel cell stack compartment; the oxygen-enriched air main pipe is connected to the airflow gap of each heatbox through oxygen-enriched air branch pipes. The exhaust gas treatment system includes a condenser, a low-pressure tank, a decarbonization device, a first compression circuit, and a second compression circuit. The input end of the condenser is connected to the output gas outlet of each fuel cell stack-heatbox module via output gas branch pipes, and the output end of the condenser is connected to the low-pressure tank. The outlet of the low-pressure tank is connected to the input end of the first compression circuit and the input end of the decarbonization device via three-way valves. The decarbonization device has a carbon dioxide output end and a reducing gas output end. The carbon dioxide output end is connected to the main carbon dioxide pipeline via a carbon dioxide circulation pipeline, and the reducing gas output end is connected to the main hydrogen pipeline via a reducing gas circulation pipeline. The first compression circuit includes a first compressor, the output end of which is connected to the high-pressure gas tank. The second compression circuit includes a second compressor, the input end of which is connected to the carbon dioxide output end and the reducing gas output end of the decarbonization device, and the output end of the second compressor is connected to the main carbon dioxide pipeline and the main hydrogen pipeline, respectively. The syngas output main pipe is connected to the reducing gas output terminal of the carbon removal device; The main intake pipe, ultrapure water main pipe, air main pipe, oxygen-enriched air main pipe, and syngas output main pipe together constitute a common main pipeline system.

2. The high-temperature co-electrolysis syngas preparation system according to claim 1, characterized in that, The first gas distribution branch is composed of gas rail group A; each of the gas rail group A is connected in series with a first shut-off valve, a first flow meter, a first fan and a first nozzle. The first input end of the first shut-off valve is connected to the carbon dioxide main pipe and the second input end is connected to the nitrogen main pipe. The output end of the first nozzle is connected to the carbon dioxide and nitrogen inlet of the corresponding fuel cell stack-heatbox module. The second gas distribution branch is composed of gas rail group B; each of the gas rail group B is connected in series with a second shut-off valve, a second flow meter, a second fan and a second nozzle. The input end of the second shut-off valve is connected to the hydrogen main pipe, and the output end of the second nozzle is connected to the hydrogen inlet of the corresponding fuel cell stack-heatbox module. Each of the air branch lines is connected in series with a third fan and a third flow meter. The input end of the third fan is connected to the main air pipe, and the output end of the third flow meter is connected to the air inlet of the fuel cell stack compartment.

3. The high-temperature co-electrolysis syngas preparation system according to claim 2, characterized in that, Both the first nozzle and the second nozzle are sonic nozzles that operate based on the critical flow principle. The flow rate of the sonic nozzle is only related to the pressure and temperature of the upstream gas.

4. The high-temperature co-electrolysis syngas preparation system according to claim 1, characterized in that, The hot box is equipped with a heating unit; The high-pressure gas tank includes a shared high-pressure gas tank, the outlet of which is connected to the carbon dioxide main pipeline and the nitrogen main pipeline.

5. The high-temperature co-electrolysis syngas preparation system according to claim 1, characterized in that, The skid-mounted assembly is divided into a fuel cell module area, a quantitative evaporation area, a gas supply area, and an exhaust gas treatment area; the multiple fuel cell-heatbox modules are arranged in the fuel cell module area, the quantitative evaporation device is located in the quantitative evaporation area, the gas supply system is located in the gas supply area, and the exhaust gas treatment system is located in the exhaust gas treatment area. The number of the fuel cell stack-thermal box modules is three or more.

6. The high-temperature co-electrolysis syngas preparation system according to claim 2, characterized in that, Each of the gas rail group A, gas rail group B, and the output end of the evaporator is equipped with an independent shut-off valve on the connecting pipeline between the gas rail group A, the gas rail group B, and each of the fuel cell stack-heatbox modules.

7. The high-temperature co-electrolysis syngas preparation system according to claim 6, characterized in that, The configuration of the independent shut-off valves enables the system to selectively establish feed atmospheres of pure water vapor, pure carbon dioxide, or a mixture of water vapor and carbon dioxide for different fuel cell stack-heatbox modules.

8. The high-temperature co-electrolysis syngas preparation system according to claim 1, characterized in that, Both the carbon dioxide circulation pipeline and the reducing gas circulation pipeline are equipped with one-way valves.

9. The high-temperature co-electrolysis syngas preparation system according to claim 1, characterized in that, The condenser cools the output gas from the fuel cell-heatbox module to 80 to 90 degrees Celsius to remove unreacted water vapor from the output gas.

Images