Medium-temperature methane dry reforming and wet reforming integrated hydrogen production device and operation method

Abstract

The invention relates to a medium-temperature methane dry reforming and wet reforming integrated hydrogen production device and an operation method. The device comprises a double-membrane reactor, a trough type solar heat collector, a heat regeneration system, an alcohol amine absorption system and a control system. According to the invention, a dry-wet reforming reaction synergistic coupling structure is designed, the wet reforming byproduct CO2 is directly used as a dry reforming raw material, a closed-loop carbon circulation path is constructed, and the utilization efficiency of carbon resources is greatly improved. A high-efficiency membrane material suitable for a medium-temperature reaction condition is adopted, a gas separation and catalysis synergistic reactor of a double-membrane structure is constructed, the high hydrogen production efficiency is ensured while the device cost is reduced, an intelligent complementary energy supply mode of solar photo-thermal and retentate gas combustion is adopted, a multi-energy coupled energy gradient utilization system is established, and the energy utilization efficiency is improved. Stable energy supply of the double-membrane reactor is ensured; through double-membrane structure design, modular integration and system optimization, a compact hydrogen production device is developed, and the compact hydrogen production device is suitable for various distributed energy scenes and meets the increasing hydrogen utilization requirements.

Description

Technical Field

[0001] This invention belongs to the field of methane reforming hydrogen production technology, specifically relating to an integrated medium-temperature methane dry reforming and wet reforming hydrogen production device and its operation method. Background Technology

[0002] Hydrogen energy, as a clean and efficient secondary energy source, has become one of the core directions of global energy transition. Methane steam reforming or wet reforming (SMR) Dry methane reforming (DMR) is currently the main technological route for industrial hydrogen production. However, traditional SMR processes suffer from problems such as high reaction temperatures (800–1000℃), high energy consumption, high CO2 emissions, and complex downstream chemical units. The reaction is an effective method for preparing H2 / CO (syngas) and one of the most promising CO2 conversion and utilization processes. It can be designed in conjunction with downstream hydrogen production processes, but it has the problem of extremely harsh reaction temperature conditions (700-1000℃).

[0003] Currently, most membrane reactors are single-membrane reactors that separate hydrogen, while dual-membrane reactors have broad research and application prospects in terms of efficient product separation and improved reaction efficiency.

[0004] Existing technology 1 (CN114604827B) discloses a system and method for producing syngas (H2, CO) based on biogas dry and wet reforming coupled with methanol cracking. However, this existing technology focuses on syngas production and has the following drawbacks: In terms of energy utilization, this invention mainly relies on the waste heat of syngas to preheat methanol and drive the cracking reaction, failing to achieve effective integration with renewable energy sources, resulting in a single energy source and limited improvement in overall system energy efficiency; In terms of device integration, this invention adopts a step-by-step conversion coupling method, with dry reforming and wet reforming reactions carried out in different reaction units, leading to large equipment size, increased operating costs, and the need for additional energy consumption to maintain the temperature of multiple reactors, which is not conducive to system miniaturization and intensification; This invention only involves the separation and utilization of CO2, failing to achieve simultaneous and efficient separation of H2 and CO2, lacking in-situ separation of high-purity hydrogen and a mechanism for immediate CO2 reuse, resulting in low product separation efficiency and limited resource utilization, making it difficult to meet the industrial demand for continuous and efficient hydrogen production.

[0005] Existing technology CN102674247A discloses a method for hydrogen production from methane through steam reforming with dual enhancement of decarbonization and dehydrogenation. However, it uses a single palladium membrane reactor for hydrogen separation, and the composite catalyst used in the decarbonization process requires interruption of the reaction process after continuous operation, and regeneration is achieved through heating and desorption, resulting in intermittent system operation. Therefore, the existing technology has the following drawbacks: the coupled dry and wet reforming scheme for methane adopts a multi-stage independent processing mode, which has problems such as complex downstream chemical units in the gas production process and low equipment space utilization efficiency, making it difficult to meet the needs of small-scale, on-site hydrogen production; the heating and desorption regeneration process of the decarbonization catalyst limits the continuity and stability of the overall operation of the device, and the palladium membrane material used for hydrogen separation is expensive, restricting its large-scale industrial application; the coupled dehydrogenation and decarbonization process is complex, with high overall energy consumption, affecting the overall reaction efficiency of the device. Summary of the Invention

[0006] In order to overcome the above-mentioned problems in the prior art, the present invention provides an integrated hydrogen production device and operation method for medium-temperature methane dry reforming and wet reforming, which is used to solve the above-mentioned problems in the prior art.

[0007] An integrated hydrogen production unit combining medium-temperature methane dry reforming and wet reforming includes: a dual-membrane reactor, a trough-type solar collector, a regeneration system, an alkanolamine absorption system, and a control system. The dual-membrane reactor is equipped with a hydrogen-permeable membrane and a carbon dioxide-permeable membrane, which divide the dual-membrane reactor into a wet methane reforming section and a dry methane reforming section. The dual-membrane reactor is installed at the focal point of the parabolic trough solar collector for providing heat to the dual-membrane reactor. The regenerative system is located below the outlet end of the dual-membrane reactor and is used to burn the permeate gas generated by the reaction in the dual-membrane reactor and return the resulting gas to the dual-membrane reactor. The alkanolamine absorption system processes the low-temperature reflux gas generated by the dual-membrane reactor to obtain CO2 gas, and then returns the gas to the dual-membrane reactor. The control system is used to monitor the overall operating status of the device.

[0008] In addition to the aspects and any possible implementations described above, a further implementation is provided in which both the hydrogen permeation membrane and the carbon dioxide permeation membrane are made of membrane materials suitable for the medium temperature range.

[0009] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the dual-membrane reactor includes an inlet zone, an outlet zone, and a reaction zone. The reaction zone includes an outermost layer, a middle layer, and an innermost layer from the outside to the inside. The outermost layer has two inlets on the inlet end face of the inlet zone of the dual-membrane reactor. Both inlets are used to introduce methane gas into the innermost layer. The outlet end side of the outlet zone has two outlets for discharging reaction permeate. The outermost layer has a high-temperature reflux gas inlet on its upper side near the outlet end and a low-temperature reflux gas outlet on its lower side near the inlet end.

[0010] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the intermediate layer is a regenerating pipe, on which a CO2 gas inlet and a water vapor inlet are provided at the inlet end near the inlet end of the dual-membrane reactor.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the regenerative system includes a burner that combusts the residual gas to obtain high-temperature reflux gas, and the high-temperature reflux gas is returned to the high-temperature reflux gas inlet via a pipeline.

[0012] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the regenerative system further includes a CO adsorption tower for adsorbing CO gas in the permeate.

[0013] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the alcohol amine absorption system includes an absorption tower, a lean-rich liquid heat exchanger, and a desorption tower connected in series.

[0014] In addition to the aspects and any possible implementations described above, a further implementation is provided in which a rich flow pump is provided between the absorption tower and the lean-rich liquid heat exchanger, and a lean flow pump is provided between the lean-rich liquid heat exchanger and the desorption tower.

[0015] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the high-temperature reflux gas includes H2, CO2, and water vapor.

[0016] The present invention also provides an operation method for an integrated medium-temperature methane dry reforming and wet reforming hydrogen production unit. The method is carried out using the aforementioned unit and includes: S1. Methane is simultaneously introduced from the inlet of the dual-membrane reactor into the wet reforming section SMR and the dry reforming section DRM within the dual-membrane reactor, and corresponding feed gas is introduced into the two sections at the same time. S2. When the solar collector of the device provides heat source, SMR and DRM generate H2 and CO2 and H2 and CO respectively under the action of temperature and catalyst. H2 is collected through hydrogen permeation membrane pipe, and part of the reaction permeate gas formed by CO2 and CO enters the reheat system for reheat treatment. The high temperature gas obtained is returned to the middle layer of the double membrane reactor and obtained as low temperature reflux gas after heat exchange. S3. The low-temperature reflux gas enters the alcohol amine absorption system through the low-temperature reflux gas outlet for recovery treatment, and the recovered CO2 enters the dual-membrane reactor through the CO2 inlet. S4. The device's control system monitors the temperature changes of the entire device in real time and makes real-time adjustments.

[0017] Beneficial effects of the present invention This invention discloses an integrated hydrogen production device and operating method for medium-temperature methane dry and wet reforming. The device includes a dual-membrane reactor, a trough solar collector, a regenerative system, an alkanolamine absorption system, and a control system. The invention designs a synergistic coupling architecture for the dry and wet reforming reactions, directly using CO2, a byproduct of wet reforming, as feedstock for dry reforming, thus constructing a closed-loop carbon cycle and significantly improving carbon resource utilization efficiency. High-efficiency membrane materials suitable for medium-temperature reaction conditions are employed, and a dual-membrane gas separation and catalytic synergistic reactor is constructed. This reduces device costs while ensuring high hydrogen production efficiency. An intelligent complementary energy supply mode combining solar thermal and residual gas combustion is adopted, establishing a multi-energy coupled energy cascade utilization system to ensure stable energy supply to the dual-membrane reactor. Through dual-membrane structure design, modular integration, and system optimization, a compact hydrogen production device is developed, suitable for various distributed energy scenarios, meeting the ever-increasing demand for hydrogen, realizing "on-demand" hydrogen production, and overcoming the technical difficulties of the traditional hydrogen energy supply chain. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the device structure of the present invention; Figure 2 This is a schematic diagram of the dual-membrane reactor structure of the present invention; Figure 3 This is a schematic diagram of the operation of the device of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the operation of the device of the present invention. Figure 2 ; Figure 5 This is a cross-sectional view of the dual-membrane reactor of the present invention. Detailed Implementation

[0019] To better understand the technical solution of this invention, the content of this invention includes, but is not limited to, the specific embodiments described below. Similar technologies and methods should be considered within the scope of protection of this invention. To make the technical problems to be solved, the technical solutions, and advantages of this invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0020] It should be understood that the embodiments described in this invention are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0021] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0022] like Figure 1 As shown, the operating environment temperature of this invention is medium temperature, i.e., 400-600℃. The medium temperature conditions required for the reaction are provided based on the Le Chatelier principle. A double-membrane structure device is used for product separation, reducing product partial pressure and continuously pushing the reaction to equilibrium, thereby allowing the integrated dry and wet reforming reaction of methane to proceed continuously, improving conversion rate and reducing reaction temperature. Figure 1 As shown, the integrated methane dry reforming and wet reforming hydrogen production device provided by the present invention includes: a dual-membrane reactor 1, a trough-type solar collector 2, a regeneration system 3, an alkanolamine absorption system 4, and a control system 5. The dual-membrane reactor 1 is provided with a hydrogen permeable membrane 6 and a carbon dioxide permeable membrane 7, which divide the dual-membrane reactor into a wet methane reforming section (SMR) and a dry methane reforming section (DMR). The dual-membrane reactor 1 is provided at the focal point of the parabolic trough solar collector 2 for providing heat to the dual-membrane reactor 1. The regenerative system is located below the outlet end of the dual-membrane reactor 1 and is used to burn the permeate generated by the reaction in the dual-membrane reactor 1, and to return the resulting high-temperature reflux gas back to the dual-membrane reactor. The alkanolamine absorption system processes the low-temperature reflux gas generated by the high-temperature reflux gas flowing into the dual-membrane reactor to obtain CO2 gas, and then returns the gas to the dual-membrane reactor. The control system is used to monitor the operating status of the dual-membrane reactor.

[0023] The dual-membrane reactor 1 is the core hydrogen production unit. Its internal structure employs a dual-membrane coupling mechanism and can be divided into an outlet zone, an inlet zone, and a reaction zone, specifically a left-end outlet zone, a right-end inlet zone, and a middle reaction zone. The middle reaction zone of the dual-membrane reactor 1 consists of three layers from the outside in: an outermost layer, a middle layer, and an innermost layer. The outermost layer is an insulation layer used to enhance the concentrating and heat collection effect, with no reactive gas flowing through it. The middle layer is equipped with a reheat pipe 10. High-temperature reflux gas enters from the high-temperature reflux gas inlet on the upper left side of the dual-membrane reactor 1. This inlet passes through the outermost layer and into the middle layer. After sufficient heat exchange, the high-temperature reflux gas becomes low-temperature reflux gas, which flows out from the low-temperature reflux gas outlet on the lower right side of the reactor 1. This low-temperature reflux gas outlet passes through the middle layer and the outermost layer into the outside environment, entering the amine absorption system 4. The innermost layer is the core reaction chamber, which is equipped with a hydrogen permeable membrane 6 and a carbon dioxide permeable membrane 7. The hydrogen permeable membrane 6 is tubular and located at the center of the reaction chamber. The carbon dioxide permeable membrane 7 is sheet-like and is fixed along the axial direction of the hydrogen permeable membrane 6 to the middle of the left and right sides of the outer periphery of the hydrogen permeable membrane 6. The double membrane structure composed of the hydrogen permeable membrane 6 and the carbon dioxide permeable membrane 7 extends axially to both ends of the reaction chamber and radially to the innermost reaction chamber wall. Several small raised platforms are set on the two side walls to support and fix the carbon dioxide permeable membrane 7 extending to this position, thereby supporting the double membrane structure. The double membrane structure is supported by the small platforms to ensure that it is fixed in the entire reaction chamber, thus dividing the reaction chamber into an upper wet reforming SMR reaction zone and a lower dry reforming DRM reaction zone. The outermost layer of the middle reaction zone is a glass tube to ensure light concentration and heat collection.

[0024] Water vapor enters reactor 1 through the upper right water vapor inlet. This inlet allows steam to pass through the outermost and middle layers and enter the innermost SMR region. CO2 enters reactor 1 through the lower right CO2 inlet. This inlet allows steam to pass through the outermost and middle layers and enter the innermost DRM region. The internal structure of the right-end inlet zone of the dual-membrane reactor 1 is as follows: Figure 5 As shown, methane gas enters through the methane inlet in the right-end inlet zone and flows into the upper wet reforming (SMR) and lower dry reforming (DRM) regions in the middle reaction zone through two outlets located on the right-end inlet zone. The internal structure of the left-end inlet zone of the dual-membrane reactor 1 is also as shown. Figure 5 As shown, the gas after the reaction (permeate gas) enters from the inlets of the two regions connecting the upper wet reforming SMR and the lower dry reforming DRM, and flows out from the permeate gas outlet on the lower side into the regenerator system. The process structure of the dual-membrane reactor 1 is as follows. Figure 2 As shown.

[0025] To ensure efficient gas separation under medium- and high-temperature conditions, a palladium-based material is selected as the hydrogen permeation membrane 6 in the dual-membrane structure, exhibiting excellent hydrogen selectivity and stability. Simultaneously, a ceramic carbonate biphase material is selected as the carbon dioxide permeation membrane 7, which possesses both high permeability and selectivity for CO2 in the medium- and high-temperature range. These two membranes work synergistically to ensure their respective separation performance while maintaining the stable progress of the reforming reaction. In practical applications, other membrane materials suitable for efficient gas separation under medium-temperature conditions and without affecting the reforming reaction can be selected for the hydrogen and carbon dioxide permeation membranes, depending on the specific circumstances. The reaction chamber is divided into two regions: upper wet reforming (SMR) and lower dry reforming (DRM). The SMR and DRM reaction catalysts are respectively filled on the upper and lower sides of the reactor. The SMR reaction occurs on the upper side of the reaction chamber, with the reaction formula as follows: The feed gas consists of CH4 and water vapor, which react with an SMR catalyst to produce H2 and CO2. H2 is separated by hydrogen permeation membrane 6 and enters the hydrogen permeation membrane pipeline. All the pure hydrogen gas obtained from the reaction flows out from the H2 outlet on the left side of the pipeline. CO2 is separated by carbon dioxide permeation membrane 7 and enters the lower part of the reaction chamber for the DRM reaction. The reaction formula is as follows: The feed gas consists of CH4 and CO2. After reacting with the DRM catalyst, H2 and CO are produced. The H2 is separated by the hydrogen permeation membrane 6 and enters the hydrogen permeation membrane pipeline, flowing out from the left side and being collected. After the reaction is complete, the remaining gas, known as permeate gas, which includes unreacted CH4 and CO2, as well as the generated CO, enters the left-end outlet zone and flows out of the dual-membrane reactor 1. Therefore, CO2 is obtained in two ways: one is by separating and transferring the CO2 generated in the SMR region to the DRM region, and the other is by additional CO2 supplied through the inlet on the lower right side of the reactor. The purpose of this is to ensure sufficient feed gas for the DRM reaction so that the reaction can proceed normally.

[0026] The hydrogen permeable membrane 6 of the present invention enables in-situ H2 separation to drive reaction equilibrium, while the carbon dioxide permeable membrane 7 regulates CO2 transfer and separation, separating the CO2 generated in the SMR region and transferring it to the DRM region.

[0027] The parabolic trough solar collector 2 serves as the core heat source of the entire device through direct solar concentrating. Its installation position is directly adjacent to the dual-membrane reactor 1, focusing sunlight onto the reactor. Specifically, the parabolic trough reflector of the parabolic trough solar collector 2 directly focuses solar radiation onto the dual-membrane reactor 1 located at its focal line, thus achieving direct conversion of light and heat energy. This direct concentrating method transfers high-temperature heat energy, reaching 400-600℃, to the reactor 1 without delay. This heat energy is essential for driving the strongly endothermic reactions such as methane vapor reforming and dry reforming within the reactor. However, to address the intermittent nature of solar energy, this invention incorporates a regenerative system to provide auxiliary high-temperature heat energy. The two systems complement each other under the control system's scheduling: when solar energy is abundant, it acts as the primary heat source for direct irradiation heating; when it is insufficient, the regenerative system uses high-temperature fuel gas generated from burning residual gas to maintain the reaction temperature, together forming a stable and efficient complementary primary and auxiliary energy supply system.

[0028] The regenerative system 3 includes a burner 8 and a regenerative pipe 10. The permeate gas generated in reactor 1 flows into the burner 8 through the permeate gas outlet of the double-membrane reactor 1 for combustion, producing high-temperature reflux gas. This high-temperature reflux gas flows into the high-temperature reflux gas inlet on the upper left side of reactor 1, flows through the regenerative pipe 10 for heat exchange, and the resulting heat energy is transferred to the innermost layer of the regenerative pipe. After heat exchange, the regenerative pipe 10 produces low-temperature reflux gas, which finally flows out from the low-temperature reflux gas outlet on the lower right side of the double-membrane reactor 1. The high-temperature gas and the raw material gas in the reaction chamber undergo countercurrent heat exchange to ensure sufficient heat transfer to the double-membrane reactor 1 and maintain the required reaction temperature. The raw material gas includes pre-mixed CH4 and water vapor required for the SMR reaction and pre-mixed CH4 and CO2 required for the DRM reaction.

[0029] like Figure 3As shown, the regenerative system 3 also includes a CO adsorption tower 11 for pretreating the permeate gas flowing out of the dual-membrane reactor 1. The CO adsorption tower 11 removes CO from the permeate gas, and existing physicochemical methods can be used for the specific treatment. After combustion and regenerative adsorption in the regenerative system 3, the low-temperature reflux gas (mainly composed of CO2) flowing out of the low-temperature reflux gas outlet then flows into the amine absorption system 4 for filtration. The amine absorption system 4 includes an absorption tower, a lean-rich liquid heat exchanger, a lean-flow pump, and a desorption tower connected in series. A rich-flow pump is installed between the absorption tower and the lean-rich liquid heat exchanger, and a lean-flow pump is installed between the lean-rich liquid heat exchanger and the desorption tower. When the system is running, the low-temperature reflux gas to be treated first enters the absorption tower through the low-temperature reflux gas outlet. The amine solution in the absorption tower selectively absorbs the CO2 to form a rich liquid. Subsequently, the rich liquid is preheated by the lean-rich liquid heat exchanger by the rich-flow pump and then enters the desorption tower by the lean-flow pump. Inside the desorption tower, the rich solution is regenerated by heating with an external heat source, releasing high-purity CO2, while the solution becomes lean. The lean solution is cooled by a heat exchanger and then returned to the absorption tower for recycling, thus forming a complete energy-saving cycle. The pure CO2 obtained from the amine absorption system 4 enters through a gas pipeline via the CO2 inlet on the lower right side of the dual-membrane reactor 1, and is reused in the DRM reaction, solving the carbon supply problem and combining integrated wet and dry reforming of methane for hydrogen production with carbon capture (i.e., CO2 capture, purification, and utilization) for recycling.

[0030] Preferably, such as Figure 4 As shown, the overall hydrogen production process is regulated by control system 5 to ensure temperature stability during the reaction. Real-time temperature monitoring of the reaction unit: Considering the three-layer structure of the reaction zone in the dual-membrane reactor 1, the goal is to control the temperature of the reaction zone to promote the reaction. A high-temperature sensor is installed in control system 5, directly embedded inside the reaction zone; its resistance value changes linearly with temperature. The resistance value measured by the high-temperature sensor is converted into a digital temperature signal by a signal conditioner and transmitted to the microcontroller in control system 5 for real-time monitoring to ensure data accuracy and reliability. The microcontroller is connected to a valve located at the high-temperature reflux gas inlet. When the temperature exceeds the set safety threshold, the microcontroller in control system 5 will send an adjustment signal, immediately adjusting the opening of the valve at the high-temperature reflux gas inlet to control the flow rate of the high-temperature reflux gas, and triggering an audible and visual alarm connected to the microcontroller in control system 5 to prevent damage to the unit due to overheating.

[0031] The parabolic trough solar collector 2 automatically tracks the sun's position and is connected to a dual-axis stepper motor. The control system 5 drives the parabolic trough solar collector 2 by controlling the connected dual-axis stepper motor, enabling it to automatically adjust its angle according to changes in the sun's azimuth and altitude angles, thereby maximizing solar energy absorption efficiency. The control system 5 monitors differences in light intensity in real time based on resistance signals from photosensors arranged around the parabolic trough solar collector 2. When the light intensity in one direction is significantly higher than in other directions, the control system 5 drives the dual-axis stepper motor to rotate towards the direction of higher light intensity, ensuring that the parabolic trough solar collector 2 is always facing the sun.

[0032] Preferably, such as Figure 4 As shown, this device can also utilize a portion of the generated high-purity H2 to power the control system 5 via the hydrogen-oxygen fuel cell 9. H2 is generated by both the SMR and DRM reactions and collected through the hydrogen permeation membrane pipe of the dual-membrane reactor 1, which exits through the leftmost hydrogen outlet in the left-hand gas outlet zone of the reactor. A small amount of the large quantity of H2 can then be diverted through the pipe and fed into the hydrogen-oxygen fuel cell 9, where the electrochemical reaction directly converts the chemical energy of hydrogen and oxygen into electrical energy to power the connected control system 5.

[0033] The novel hydrogen production device of methane dry / wet reforming, which combines a dual-membrane reactor and solar-combustion complementary power supply, uses concentrated solar power to drive the methane / water vapor reaction and utilizes the membrane reactor to continuously separate the products, thereby breaking the chemical equilibrium to achieve a clean energy technology for efficient hydrogen production at medium temperature (400-600℃). It features low temperature, high efficiency, and minimal structure, and is suitable for distributed hydrogen production.

[0034] The device in this invention combines the DRM reaction with the SMR reaction to establish a coupled wet and dry reforming hydrogen production system for methane. This solves the emission reduction problems of high carbon emissions and inefficient utilization of captured CO2 gas during hydrogen production, thereby improving feedstock utilization. Regarding the dual-membrane separation technology, this invention employs a hydrogen-permeable membrane 6 and a carbon dioxide-permeable membrane 7 working in synergy to achieve efficient in-situ separation of reaction products, thus promoting the forward reaction, improving reforming efficiency, and reducing reaction temperature. The device utilizes the medium-to-high temperature heat energy generated by the combustion of residual gas and solar thermal energy to form a complementary energy supply system, solving the problem of intermittent renewable energy and ensuring the temperature stability and optimized energy consumption control of the reaction process. All components in the device are modular and integrated, resulting in a compact structure and small footprint. This "on-demand" hydrogen production mode effectively solves the hydrogen storage and transportation problems and can be widely applied in distributed energy scenarios, providing a new technological option for end-use applications such as hydrogen refueling stations.

[0035] As an embodiment of the present invention, the present invention also provides an operation method for an integrated medium-temperature methane dry reforming and wet reforming hydrogen production device. The method is carried out using the device of the present invention, including: S1. Methane is simultaneously introduced from the gas inlet of the device into the wet reforming section SMR and the dry reforming section DRM in the dual membrane reactor, and corresponding feed gas is introduced into the two sections at the same time. S2. When the solar collector of the device provides heat, SMR and DRM generate H2 and CO2 and H2 and CO respectively under the action of temperature and catalyst. H2 is collected through the hydrogen permeation membrane pipe, a part of CO2 participates in the DRM reaction through the carbon dioxide permeation membrane, and the remaining unreacted CO2, CO generated by the DRM reaction and other unreacted gases enter the reheat system for reheat treatment. The high-temperature gas obtained is returned to the middle layer of the double membrane reactor and obtained as low-temperature reflux gas after heat exchange. S3. The low-temperature reflux gas enters the alcohol amine absorption system through the low-temperature reflux gas outlet for recovery treatment, and the recovered CO2 enters the dual-membrane reactor through the CO2 inlet. S4. The device's control system monitors the temperature changes of the entire device in real time and makes real-time adjustments.

[0036] Specifically, the entire process of the device is as follows: Methane is simultaneously introduced into the SMR and DRM regions from the right side of reactor 1, while the corresponding feed gases are introduced into both regions. Under the influence of temperature and catalyst, the SMR and DRM reactions produce H2 and CO2, and H2 and CO, respectively. The H2 obtained from both regions is collected through hydrogen permeate membrane pipes. The device is heated primarily by a solar collector. Residual gas from the reaction enters the burner for combustion; the resulting high-temperature gas flows back into the intermediate layer of the dual-membrane reactor 1 via a reheat pipe as an auxiliary heat source, and finally enters the amine absorption system to recover the CO2. The control system 5 monitors temperature changes in real time using sensors and controls the high-temperature reflux gas valve to precisely regulate the reaction temperature, maintaining it within a stable range. Power is supplied by a hydrogen-oxygen fuel cell. The overall process design ensures the feasibility and continuous stable operation of the device.

[0037] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. An integrated hydrogen production unit for medium-temperature methane dry reforming and wet reforming, characterized in that, include: Dual-membrane reactor, trough solar collector, regenerative system, amine absorption system and control system, The dual-membrane reactor is equipped with a hydrogen-permeable membrane and a carbon dioxide-permeable membrane, which divide the dual-membrane reactor into a wet methane reforming section and a dry methane reforming section. The dual-membrane reactor is installed at the focal point of the parabolic trough solar collector for providing heat to the dual-membrane reactor. The regenerative system is located below the outlet end of the dual-membrane reactor and is used to burn the permeate gas generated by the reaction in the dual-membrane reactor and return the resulting gas to the dual-membrane reactor. The alkanolamine absorption system processes the low-temperature reflux gas generated by the dual-membrane reactor to obtain CO2 gas, and then returns the gas to the dual-membrane reactor. The control system is used to monitor the overall operating status of the device.

2. The apparatus according to claim 1, characterized in that, Both the hydrogen permeation membrane and the carbon dioxide permeation membrane are made of membrane materials suitable for the medium temperature range.

3. The apparatus according to claim 1 or 2, characterized in that, The dual-membrane reactor includes an inlet zone, an outlet zone, and a reaction zone. The reaction zone consists of an outermost layer, a middle layer, and an innermost layer from the outside to the inside. The outermost layer has two inlets on the inlet end face of the inlet zone of the dual-membrane reactor. Both inlets are used to introduce methane gas into the innermost layer. The outlet end of the outlet zone has two outlets on its side for discharging residual reaction gas. The outermost layer has a high-temperature reflux gas inlet on its upper side near the outlet end and a low-temperature reflux gas outlet on its lower side near the inlet end.

4. The apparatus according to claim 3, characterized in that, The intermediate layer is a regenerating pipe, on which a CO2 gas inlet and a water vapor inlet are provided near the inlet end of the dual-membrane reactor.

5. The apparatus according to claim 3, characterized in that, The regenerative system includes a burner that burns the residual gas to obtain high-temperature reflux gas, which is then returned to the high-temperature reflux gas inlet via a pipeline.

6. The apparatus according to claim 1, characterized in that, The regenerative system also includes a CO adsorption tower for adsorbing CO gas in the residual gas.

7. The apparatus according to claim 1, characterized in that, The alcohol amine absorption system includes an absorption tower, a lean and rich liquid heat exchanger, and a desorption tower connected in series.

8. The apparatus according to claim 7, characterized in that, A rich flow pump is installed between the absorption tower and the lean-rich liquid heat exchanger, and a lean flow pump is installed between the lean-rich liquid heat exchanger and the desorption tower.

9. The apparatus according to claim 5, characterized in that, The high-temperature reflux gas includes H2, CO2, and water vapor.

10. A method for operating an integrated medium-temperature methane dry reforming and wet reforming hydrogen production unit, characterized in that, The method is carried out using the apparatus according to any one of claims 1-9, comprising: S1. Methane is simultaneously introduced from the inlet of the dual-membrane reactor into the wet reforming section SMR and the dry reforming section DRM in the dual-membrane reactor, and corresponding feed gas is introduced into the two sections at the same time. S2. When the solar collector of the device provides heat source, SMR and DRM generate H2 and CO2 and H2 and CO respectively under the action of temperature and catalyst. H2 is collected through hydrogen permeation membrane pipe, and part of the reaction permeate gas formed by CO2 and CO enters the reheat system for reheat treatment. The high temperature gas obtained is returned to the middle layer of the double membrane reactor and obtained as low temperature reflux gas after heat exchange. S3. The low-temperature reflux gas enters the alcohol amine absorption system through the low-temperature reflux gas outlet for recovery treatment, and the recovered CO2 enters the dual-membrane reactor through the CO2 inlet. S4. The device's control system monitors the temperature changes of the entire device in real time and makes real-time adjustments.

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