Hydrogen separation and CO2 adsorption synergistic enhanced solar methanol reforming hydrogen production system

Abstract

The invention relates to the technical field of solar thermochemical utilization and hydrogen preparation, and discloses a hydrogen separation and CO2 adsorption synergistic reinforced solar methanol reforming hydrogen production system, which integrates a reaction unit and a separation unit, and solves the problem of reaction separation disjunction of a traditional system. In the prior art, most of a reaction unit, a carbon dioxide removal unit and a hydrogen separation unit are independent equipment and need to be connected through pipelines, and the problems of heat loss, reaction inhibition and the like exist. The membrane-adsorption coupling reaction separation unit adopts an integrated reforming reaction kettle structure of a glass tube, a vacuum region, a heat absorption tube, a reaction region and a hydrogen permeable membrane, and four functions of solar heat absorption, methanol steam reforming reaction, carbon dioxide adsorption removal and hydrogen selective separation are integrated and designed in the same equipment; real-time cooperation of reaction and separation is guaranteed from the space structure, the space utilization rate is improved, meanwhile, heat loss and the reaction inhibition effect are greatly reduced, and the overall efficiency of the system is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of solar thermochemical utilization and hydrogen production technology, specifically a solar methanol reforming hydrogen production system that synergistically enhances hydrogen separation and CO2 adsorption. Background Technology

[0002] Against the backdrop of a global energy structure transition towards cleaner and lower-carbon energy, hydrogen energy, with its advantages of high energy density, combustion byproducts consisting only of water, and zero carbon emissions throughout its entire lifecycle, has demonstrated enormous application potential in transportation, distributed energy, and industrial decarbonization, becoming a key strategic direction for addressing climate change and ensuring energy security. However, the large-scale application of hydrogen energy heavily relies on efficient, low-cost, and low-energy-consumption hydrogen production technologies. Currently, the mainstream hydrogen production method still primarily relies on fossil fuels (such as natural gas steam reforming). This technological path not only consumes non-renewable resources but also generates substantial carbon dioxide emissions, fundamentally contradicting the "clean" nature of hydrogen energy. Therefore, developing green and low-carbon hydrogen production technologies has become a core direction for the industry's development.

[0003] Among various low-carbon hydrogen production technologies, methanol steam reforming has become a research hotspot in the field of low-carbon hydrogen production over the past decade due to its advantages such as the wide availability of methanol, safe and convenient storage and transportation, and mild reforming reaction conditions (typically a reaction temperature of 280-320℃, far lower than the 700-900℃ of natural gas steam reforming). Its core reaction process includes methanol steam reforming and methanol decomposition. The carbon monoxide generated by the latter is further converted into carbon dioxide and additional hydrogen through a water-gas shift reaction, with the ultimate goal of obtaining high-purity hydrogen products.

[0004] Despite the significant advantages of methanol steam reforming for hydrogen production, the existing technology system still faces three major bottlenecks that severely restrict its industrial application and green upgrading: First, energy consumption and carbon emissions are prominent issues. Methanol steam reforming is an endothermic reaction, and traditional systems rely on the combustion of fossil fuels (such as natural gas and diesel), which not only leads to additional carbon emissions but also consumes non-renewable fossil energy resources. Compared to the ideal state of consuming only methanol feedstock, this significantly increases energy consumption.

[0005] Second, the product separation efficiency is low, limiting the purity and yield of hydrogen. The products of methanol steam reforming are a mixture of hydrogen, carbon dioxide, carbon monoxide, and water vapor. Traditional systems require multi-step separation processes to purify the hydrogen. While pressure swing adsorption (PSA) can produce high-purity hydrogen (above 99.9%), it suffers from problems such as large equipment size, high investment costs, the need for regular adsorbent replacement, and low hydrogen yield (typically only 70%-85%). Conventional membrane separation technology is limited by the permeation selectivity and flux of the membrane material, making it difficult to simultaneously meet the requirements of high purity and high yield. Furthermore, unreacted methanol and carbon dioxide cannot be separated in time, inhibiting the forward reforming reaction from methanol and water to hydrogen and carbon dioxide (according to Le Chatelier's principle), further reducing the hydrogen production efficiency.

[0006] Third, the system integration is low, and energy utilization efficiency needs to be improved. Existing methanol steam reforming hydrogen production systems typically design the reaction unit, heating unit, and separation unit independently, resulting in poor energy coupling between the units and significant heat loss (e.g., the waste heat of the reaction products is not effectively recovered and utilized for preheating the raw materials). At the same time, the coupled application of renewable energy sources such as solar energy is still in the exploratory stage. Most solar-driven systems only use solar collectors to directly heat the reactor without coordinating with the product separation process, resulting in low solar energy utilization efficiency.

[0007] In summary, current methanol steam reforming hydrogen production technology still has significant shortcomings in terms of green energy sources, efficient product separation, and synergistic system integration. There is an urgent need to develop a new type of hydrogen production system that can combine solar energy drive and efficient product separation to achieve stable production of low-energy-consumption, zero-emission, and high-purity hydrogen, and promote the green development of small and medium-sized hydrogen energy industries. Summary of the Invention

[0008] This invention provides a solar-powered methanol reforming hydrogen production system that synergistically enhances hydrogen separation and CO2 adsorption, solving the problems of non-clean energy sources, low product separation efficiency, and poor system integration in existing methanol steam reforming hydrogen production technologies.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A solar-powered methanol reforming hydrogen production system that synergistically enhances hydrogen separation and CO2 adsorption includes a membrane-adsorption coupled reaction separation unit. This unit is an integrated reactor comprising, from the outside to the inside, a glass tube, a heat absorber tube, and a hydrogen permeation membrane. The glass tube, heat absorber tube, and hydrogen permeation membrane are sealed together. A vacuum zone is established between the glass tube and the heat absorber tube. The reactor is sealed on both sides by a sealing assembly. A pretreated methanol-water solution is introduced into one side of the area between the heat absorber tube and the hydrogen permeation membrane, and an outlet is provided on the other side. Water vapor is introduced into one side of the area inside the hydrogen permeation membrane, and an outlet is provided on the other side. The reactor is mounted on a solar-coupled heating unit.

[0010] Preferably, the solar-coupled heating unit includes a trough solar collector, on which multiple crossbeams are evenly and parallelly arranged. The multiple crossbeams are fixed by two longitudinal beams, which are perpendicular to the crossbeams. Multiple crossbeam fixing seats are provided on the longitudinal beams, and the multiple crossbeams are fixed by the multiple crossbeam fixing seats. Each crossbeam is connected to an A-type bracket assembly, and the apexes of the multiple A-type bracket assemblies are on a uniform horizontal line. The reactor is fixedly installed on the line connecting the apexes of the multiple A-type bracket assemblies.

[0011] Preferably, the lower end of each type A bracket assembly is fixedly connected to the corresponding crossbeam via a crossbeam fixing seat, and the upper end is fixed to the reactor via a U-shaped support frame.

[0012] Preferably, the parabolic trough solar collector adopts a parabolic design, and the elevation angle adjustment range of the parabolic trough solar collector is 30°-60°.

[0013] Preferably, the area between the heat absorber and the hydrogen permeation membrane is filled with a mixture of Cu-based Al2O3-ZnO methanol steam reforming hydrogen production catalyst and modified hydrotalcite-based carbon dioxide adsorbent.

[0014] Preferably, the hydrogen permeation membrane is coaxially disposed inside the heat absorber tube, and the membrane material is a palladium-silver alloy.

[0015] Preferably, the inner diameter of the glass tube is 1.5-2.0 times the inner diameter of the heat-absorbing tube, and the inner diameter of the hydrogen permeation membrane is 0.4-0.6 times the inner diameter of the heat-absorbing tube.

[0016] Preferably, the water vapor and methanol-water solution are provided through a raw material pretreatment unit, which includes a methanol storage tank and a deionized water storage tank. The deionized water storage tank outputs two streams of deionized water, which enter the first preheater and the raw material mixer, respectively. The deionized water in the first preheater is heated and then input into the internal region of the hydrogen permeation membrane. The methanol storage tank outputs methanol to the raw material mixer, where it is mixed to form a methanol-water solution, which then enters the second preheater. The methanol-water solution is heated and then input into the region between the heat absorber and the hydrogen permeation membrane.

[0017] Preferably, the molar ratio of methanol to deionized water in the methanol-water solution is 1:1.1 to 1:2.0.

[0018] Preferably, a U-shaped bracket is evenly threaded through the heat absorption tube, and a support is connected to the U-shaped bracket, with the other end of the support supporting the hydrogen permeation membrane.

[0019] Compared with existing technologies, this invention has the following advantages: This invention provides a solar-powered methanol reforming hydrogen production system that synergistically enhances hydrogen separation and CO2 adsorption, integrating the reaction and separation units into a single design, thus solving the problem of reaction and separation disconnect in traditional systems. In existing technologies, the reaction unit, carbon dioxide removal unit, and hydrogen separation unit are mostly independent devices that need to be connected by pipelines, resulting in heat loss and reaction inhibition. The membrane-adsorption coupled reaction and separation unit of this invention adopts an integrated reforming reactor structure of "glass tube-vacuum region-heat absorber tube-reaction region-hydrogen permeation membrane," integrating the four major functions of solar heat absorption, methanol steam reforming reaction, carbon dioxide adsorption and removal, and selective hydrogen separation into a single device. This spatial structure ensures real-time synergy between reaction and separation, improving space utilization while significantly reducing heat loss and reaction inhibition effects, thus significantly improving the overall system efficiency.

[0020] Furthermore, in existing technologies, hydrogen separation often employs either "negative pressure extraction" or "single membrane separation." The former can easily lead to excessive pressure differences across the membrane, damaging the membrane material; the latter is limited by product accumulation on the membrane surface, resulting in low permeation efficiency. The membrane-adsorption coupled reaction separation unit of this invention adopts a structural design of "reaction zone - hydrogen permeation membrane - sweeping zone," where the sweeping zone is the internal region of the hydrogen permeation membrane, and the reaction zone is the region between the heat absorber and the hydrogen permeation membrane. Water vapor is introduced into the sweeping zone through the inlet. On one hand, the partial pressure difference between water vapor and hydrogen allows hydrogen to rapidly permeate from the reaction zone into the sweeping zone; on the other hand, the water vapor can gently purge the membrane surface, reducing membrane fouling caused by impurity adsorption and extending the membrane's service life.

[0021] Furthermore, existing technologies rely on fossil fuel heating or indirect heating methods using "solar energy + heat transfer oil circulation," which suffer from problems such as large carbon emissions or heat loss. This invention, through the direct heat absorption design of a membrane-adsorption coupled reaction separation unit, allows solar energy to be focused by a reflector and directly absorbed by the heat absorber tube and transferred to the reaction zone. This eliminates the need for fossil fuels, and apart from the carbon dioxide generated in the reforming reaction, the entire process produces no additional carbon emissions, significantly improving the environmental friendliness and energy efficiency of the hydrogen production process.

[0022] Furthermore, existing systems require separate reactors, carbon dioxide adsorption towers, hydrogen separation systems, solar collectors, and complex piping connections, resulting in large equipment size, high investment costs, and difficult maintenance. This invention integrates the membrane-adsorption coupled reaction separation unit into a single reactor, achieving a compact size, reducing piping, valves, and other auxiliary equipment, lowering maintenance costs during operation, and improving system reliability and integration. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a connection diagram of the raw material pretreatment unit and the membrane-adsorption coupled reaction separation unit in an embodiment of the present invention; Figure 2 This is a structural diagram of the solar-coupled heating unit according to an embodiment of the present invention; Figure 3 This is a structural diagram of the membrane-adsorption coupling reaction separation unit in an embodiment of the present invention; Figure 4 This is a schematic diagram of the material inlet and outlet of the membrane-adsorption coupled reaction separation unit in an embodiment of the present invention; Figure 5 This is a schematic diagram of the A-type bracket assembly structure of the solar-coupled heating unit according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the beam fixing seat structure of the solar coupling heating unit according to an embodiment of the present invention; In the diagram, 1. Sweeping zone feed inlet, 2. Valve No. 2, 3. First preheater, 4. Metering pump No. 1, 5. Metering pump No. 2, 6. Three-way valve, 7. Deionized water storage tank, 8. Methanol storage tank, 9. Valve No. 1, 10. Metering pump No. 3, 11. Raw material mixer, 12. Valve No. 3, 13. Second preheater, 14. Valve No. 4, 15. Reaction zone feed inlet, 16. Type A support assembly No. 1, 17. Reactor, 18. Type A support assembly No. 2, 19. Long support for reflector No. 1, 20. Type A support assembly No. 3, 21. Trough solar collector, 22. Type A support assembly No. 4, 23. Long support for reflector No. 2, 24. Type A support assembly No. 5, 25. Reflector support frame No. 1, 26. Fifth crossbeam, 27. Fourth crossbeam, 28. 29. Second crossbeam, 30. First crossbeam, 31. Second reflector support frame, 32. Glass tube, 33. Absorber tube, 34. Hydrogen permeation membrane, 35. U-shaped bracket, 36. Membrane support frame, 37. Membrane support frame, 38. Hex nut, 39. Reaction zone outlet, 40. External flange, 41. Internal flange, 42. Hex nut, 43. Hex nut, 44. Sweeping zone outlet, 45. Columnar support base, 46. Long rod, 47. Short rod, 48. U-shaped support frame, 49. Long rod, 50. Columnar support base, 51. Hex nut, 52. Hex nut, 53. Hex nut, 54. Hex nut, 55. Crossbeam fixing seat, 56. Hex nut, 8. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components.

[0029] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] like Figure 3 As shown, this invention provides a solar-powered methanol reforming hydrogen production system that synergistically enhances hydrogen separation and CO2 adsorption. The system includes a membrane-adsorption coupled reaction separation unit, which is an integrated reactor. From the outside to the inside, the reactor consists of a glass tube 32, a heat-absorbing tube 33, and a hydrogen permeation membrane 34. The glass tube 32, heat-absorbing tube 33, and hydrogen permeation membrane 34 are sealed together. A vacuum zone is established between the glass tube 32 and the heat-absorbing tube 33. The reactor is sealed on both sides by a sealing assembly. A pretreated methanol-water solution is introduced into one side of the area between the heat-absorbing tube 33 and the hydrogen permeation membrane 34, and an outlet is provided on the other side. Water vapor is introduced into one side of the internal area of ​​the hydrogen permeation membrane 34, and an outlet is provided on the other side. The reactor is mounted on a solar-coupled heating unit.

[0031] By synergistically designing a membrane-adsorption coupled reaction separation unit and a solar-coupled heating unit, this technology effectively overcomes the bottlenecks of existing methanol steam reforming hydrogen production technology. It replaces fossil fuel heating with solar-powered heating, avoiding additional carbon emissions and non-renewable resource consumption, thus achieving a green energy source. The integrated reactor can instantly separate reaction products, driving the reforming reaction forward, improving hydrogen purity and yield, and overcoming the low efficiency and reaction-restricting problems of traditional separation processes. The efficient coupling of each unit enhances system integration, reduces heat loss, and improves energy utilization efficiency. Ultimately, this achieves stable production of low-energy-consumption, zero-emission, high-purity hydrogen, contributing to the green development of small and medium-sized hydrogen energy industries.

[0032] The detailed design of this invention is as follows: This invention utilizes a solar trough collector capable of tracking the sun to collect solar energy and convert it into heat energy to drive a hydrogen production reaction within an integrated reforming reactor. The integrated design concentrates the solar heating process, methanol steam reforming reaction process, carbon dioxide adsorption process, and hydrogen permeation process inside the reactor. This allows the adsorbent to perform carbon dioxide adsorption and hydrogen permeation simultaneously with the methanol steam reforming hydrogen production reaction, reducing the products of the forward reaction of methanol steam reforming, shifting the reaction equilibrium to the right, thereby increasing the methanol conversion rate and hydrogen yield. The entire system also boasts advantages such as high hydrogen purity, fast reaction efficiency, and low carbon emissions.

[0033] The design process of this invention is as follows: For the raw material pretreatment unit, firstly, based on the hydrogen production scale, the raw material consumption is calculated, the volume of the water storage tank and methanol storage tank is determined, and a filter is installed at the outlet of the storage tank to avoid raw material contamination. Then, based on the raw material ratio and flow accuracy requirements, a suitable metering pump is selected to ensure the molar ratio error of methanol and deionized water. For the solar heating unit, firstly, based on the heat required for the reaction, a suitable trough-type solar collector is selected. The parabolic surface of the collector adopts a parabolic design with a reflectivity ≥95%. It is fixed by a reflector bracket assembly to ensure that the focal line of the collector coincides with the axis of the membrane-adsorption coupling reaction separation unit. The elevation angle adjustment range is 30°-60° to adapt to different solar altitude angles. The reflector and the reflector bracket are fixed with hexagonal nuts. For the membrane-adsorption coupling reaction separation unit, a "glass tube" is used. The multi-layered coaxial cylindrical structure, consisting of a vacuum zone, absorber tube, reaction zone, hydrogen permeation membrane, and sweeping zone, ensures axial coordination of functions such as sunlight penetration, heat insulation, heat transfer, reaction, and gas separation, avoiding efficiency losses caused by spatial misalignment of functional modules. The glass tube is made of high borosilicate glass with excellent light transmittance. The vacuum zone is designed according to vacuum insulation technology standards to ensure that the system's heat loss is ≤5%. The absorber tube is made of a high-temperature resistant alloy with excellent thermal conductivity and coated with a high absorptivity and low emissivity coating. The reaction zone is based on reaction kinetics and adsorption kinetics models to calculate the filling amounts of catalyst and carbon dioxide adsorbent, ensuring sufficient residence time for raw materials to meet reaction completion requirements, while matching the efficiency of the absorber tube to avoid local overheating or insufficient temperature. The hydrogen permeation membrane is a palladium-silver alloy membrane, and the membrane module is fixed inside the absorber tube by a membrane support inside the absorber tube.

[0034] like Figure 1 As shown, the raw material pretreatment unit includes a sweeping zone inlet 1, a second valve 2, a first preheater 3, a first metering pump 4, a second metering pump 5, a three-way valve 6, a deionized water storage tank 7, a methanol storage tank 8, a first valve 9, a third metering pump 10, a raw material mixer 11, a third valve 12, a second preheater 13, a fourth valve 14, and a reaction zone inlet 15.

[0035] Three-way valve 6 is connected via pipelines to deionized water storage tank 7, metering pump 4 (number one), and metering pump 5 (number two), enabling the transport of deionized water to the raw material mixer and the first preheater. Metering pump 4 is connected via pipelines to three-way valve 6 and the first preheater 3, providing power and controlling the flow rate of deionized water from the deionized water storage tank to the first preheater. Metering pump 5 is connected via pipelines to three-way valve 6 and the raw material mixer 11, providing power and controlling the flow rate of deionized water from the deionized water storage tank to the raw material mixer. The first preheater 3 is connected via pipelines to valve 2 (number two) and metering pump 4 (number one), heating the deionized water into steam for transport to the sweeping zone inlet. Valve 2 (number two) is connected via pipelines to the first preheater 3 and the sweeping zone inlet 1, controlling the opening and closing of the pipeline between the first preheater 3 and the sweeping zone inlet 1. Valve 9... The methanol storage tank 8 and the third metering pump 10 are connected by pipes to control the flow between the methanol storage tank 8 and the raw material mixer pipe 11. The third metering pump 10 is connected by pipes to the first valve 9 and the raw material mixer 11 to provide power for transporting methanol liquid from the methanol storage tank 8 to the raw material mixer 11 and to control its flow rate. The raw material mixer 11 is connected by pipes to the third metering pump 10 and the third valve 12. It has a built-in stirring device that can uniformly mix methanol liquid and deionized water according to a set molar ratio. The third valve 12 is connected by pipes to the raw material mixer 11 and the second preheater 13 to control the flow between the raw material mixer 11 and the second preheater 13. The fourth valve 14 is connected by pipes to the second preheater 13 and the reaction zone inlet 15 to control the flow between the second preheater 13 and the reaction zone inlet 15.

[0036] like Figure 2 As shown, the present invention discloses a solar methanol vapor reforming hydrogen production system based on hydrogen permeation membrane and carbon dioxide adsorption enhancement, comprising a first type A support assembly 16, a reactor 17, a second type A support assembly 18, a first reflector long support 19, a third type A support assembly 20, a trough solar collector 21, a fourth type A support assembly 22, a second trough solar collector long support 23, a fifth type A support assembly 24, a first trough solar collector support frame 25, a fifth crossbeam 26, a fourth crossbeam 27, a third crossbeam 28, a second crossbeam 29, a first crossbeam 30, and a second trough solar collector support frame 31.

[0037] The first crossbeam 30, the second crossbeam 29, the third crossbeam 28, the fourth crossbeam 27, and the fifth crossbeam 26 are parallel and equidistantly distributed along the length of the system, and are all installed above the trough solar collector 21. Type A bracket assemblies 16, 18, 20, 22, and 24 are vertical support components, equidistantly arranged along the length of the system. The lower end of each Type A bracket assembly is fixedly connected to the corresponding crossbeam via a measuring fixing seat, and the upper end is fixed to the reactor via a U-shaped support frame. Long supports 19 and 23 of the first and second trough solar collectors are longitudinally extending rods, their extension direction perpendicular to the crossbeams, closely attached to both sides of the trough solar collector 21, and fixed to the crossbeams above them via crossbeam fixing seats. The No. 1 trough solar collector support frame 25 and the No. 2 trough solar collector support frame 31 are horizontal connecting components used to fix the position of the trough solar collector 21.

[0038] The parabolic trough solar collector 21 employs a parabolic reflector structure with a reflectivity of ≥95%, enabling efficient collection and focused reflection of solar radiation. The collector is fixed via a combination of a reflector end bracket and a crossbeam bracket, constructed from high-strength aluminum alloy to ensure structural stability and wind resistance. The reflector and bracket are securely connected with hexagonal nuts, ensuring convenient assembly and disassembly while maintaining reliable fixation. This unit can track the sun's trajectory in real time, focusing and reflecting the collected solar energy onto the absorber tubes of the membrane-adsorption coupled reaction separation unit. This directly provides a continuous and stable heat source for the methanol vapor reforming hydrogen production reaction within the reactor, eliminating the need for additional fossil fuels and achieving a greener hydrogen production process.

[0039] like Figure 3 , Figure 4 As shown, the membrane-adsorption coupled reaction separation unit includes a glass tube 32, a heat absorption tube 33, a hydrogen permeation membrane 34, a U-shaped support frame 35, a first membrane support 36, a second membrane support 37, a first hexagonal nut 38, a reaction zone outlet 39, an external flange 40, an internal flange 41, a second hexagonal nut 42, a third hexagonal nut 43, and a sweeping zone outlet 44.

[0040] Glass tube 32 serves as the external cavity of the membrane-adsorption coupled reaction separation unit, forming the space for accommodating the reaction and separation units. Absorber tube 33 is coaxially nested inside glass tube 32, providing a heat transfer carrier for the reaction. Hydrogen permeation membrane 34 is coaxially placed inside absorber tube 33. Six sets of U-shaped supports 35 are evenly distributed inside absorber tube 33, providing stable support for the hydrogen permeation membrane structure. Membrane support 36 (number one) and membrane support 37 (number two) are fixed below the U-shaped supports 35, providing support. The inner flange 41 is sealed to the port of glass tube 32 using a glass-metal welding method. Absorber tube 33 is fixed to the groove of inner flange 41. Outer flange 39 is fastened to inner flange 41 using hexagonal nuts 38 (number one), 42 (number two), and 43 (number three), achieving a sealed connection between this unit and other components of the system. The discharge port 39 of the reaction zone and the discharge port 44 of the sweeping zone are fixed above outer flange 40.

[0041] Based on structural size matching and functional adaptability, the relative sizes of each core component need to be set in accordance with two core principles: the annual average solar heat flux density and the target hydrogen production scale. Taking the inner diameter of the absorber tube 33 as the design standard, set as M1, its size is equal to the outer diameter of the reaction zone. The design principle is to ensure that energy can be transferred to the reaction system quickly and uniformly. If the target hydrogen production scale is large, the diameter of the absorber tube and the inner diameter of the reaction zone need to be increased simultaneously, while maintaining a stable ratio between the two to avoid a decrease in reaction efficiency due to insufficient heat supply. The inner diameter M2 of the glass tube 32, which serves as the incident channel, needs to be 1.5 to 2.0 times the inner diameter M1 of the absorber tube. Sufficient insulation space should be reserved in the empty area to meet its design standards. If the annual average solar heat flux density of the project site is low, the diameter ratio of glass tube 32 to absorber tube 33 should be appropriately increased to improve the solar energy received per unit area. The space size of the reaction area and the sweeping area should be designed in a coordinated manner. The inner diameter M3 of the permeate membrane should be 0.4 to 0.6 times the inner diameter M1 of the absorber tube. Its size should be determined in combination with the size of the reaction area and the hydrogen permeability to avoid the membrane module being too large and encroaching on the space of the reaction area. The hydrogen separation efficiency should be ensured through reasonable membrane area design, and the size of each component should be coordinated with the solar energy utilization efficiency and hydrogen production capacity.

[0042] The reaction zone is filled with a mixture of Cu-based Al2O3-ZnO methanol steam reforming hydrogen production catalyst and modified hydrotalcite-based carbon dioxide adsorbent. The raw materials are provided by the raw material pretreatment unit and enter the reactor from the raw material inlet. Under specific temperatures of 280℃~320℃ and pressures of 0.1~0.3 MPa, methanol steam reforming and water-gas shift reactions occur simultaneously in the reactor, efficiently converting methanol into hydrogen, carbon dioxide, and trace amounts of carbon monoxide. The modified hydrotalcite-based carbon dioxide adsorbent selectively adsorbs carbon dioxide generated in the catalyst layer based on the Le Chatelier principle at the reaction temperature, promptly removing carbon dioxide and promoting the methanol steam reforming hydrogen production reaction from methanol and water to hydrogen and carbon dioxide in the forward direction, significantly improving the methanol conversion rate and hydrogen production.

[0043] The hydrogen permeation membrane 34 is located inside the absorber tube and is made of palladium-silver alloy. One side of the membrane is the reaction zone, and the other side is the sweeping zone. Water vapor is introduced into the sweeping zone through the sweeping inlet. Based on the difference in hydrogen partial pressure on both sides, the hydrogen generated in the reaction zone is rapidly and selectively passed through the hydrogen permeation membrane 34 into the sweeping zone. Since there is a significant difference in boiling points between water vapor and hydrogen, the mixed gas can be condensed and separated at the outlet of the sweeping zone to obtain hydrogen with a purity of 99.9%. The unpermeated gas and unreacted methanol vapor will be discharged through the reaction zone outlet of the reaction zone, and subsequent gas separation and waste heat recovery can be carried out.

[0044] like Figure 5 , Figure 6 As shown, the A-type bracket assembly includes a first columnar support base 45, a first long rod 46, a short rod 47, a U-shaped support frame 48, a second long rod 49, a second cylindrical support base 50, a fourth hexagonal nut 51, a fifth hexagonal nut 52, a sixth hexagonal nut 53, a seventh hexagonal nut 54, a crossbeam fixing seat 55, and a eighth hexagonal nut 56.

[0045] The U-shaped support frame 48 is connected to the first long rod 46 and the second long rod 48 via grooves. The reactor 17 is placed above the U-shaped support frame 48. The short rod 47 is connected to the first long rod 46 and the second long rod 49 by welding. The first long rod 46 is fixed above the first cylindrical support base 45, and the second long rod 49 is fixed above the second cylindrical support base 50. The crossbeam is connected to the A-type bracket by the fourth hexagonal nut 51 and the fifth hexagonal nut 52. The crossbeam and the crossbeam fixing seat 55 are fastened together with the seventh hexagonal nut 57 and the eighth hexagonal nut 56. The long bracket of the trough solar collector is fixed together with the crossbeam fixing seat 55 with the sixth hexagonal nut 53.

[0046] This invention also provides a method for operating a solar-powered methanol reforming hydrogen production system that synergistically enhances hydrogen separation and CO2 adsorption: 1. Before system startup, conduct airtightness tests on the raw material pretreatment unit, solar coupled heating unit, and membrane-adsorption coupled reaction separation unit to ensure that there are no leaks at the pipe, valve, and equipment connections; at the same time, check the positioning accuracy and support stability of the trough solar collector in the solar coupled heating unit, as well as the filling status of the catalyst and adsorbent in the membrane-adsorption coupled reaction separation unit.

[0047] 2. Start the raw material pretreatment unit and use metering pumps to draw raw materials from the methanol storage tank and deionized water storage tank respectively. The raw materials are delivered to the raw material mixer at a molar ratio of 1:1.1 to 1:2.0 and mixed to form a uniform methanol-water solution. After preheating, the solution is delivered to the feed inlet of the reaction zone of the membrane-adsorption coupling reaction separation unit.

[0048] 3. Monitor the solar heat flow intensity in real time. If the solar heat is insufficient to maintain the temperature of the reaction zone in the range of 280-320℃, adjust the output power of metering pumps No. 1, No. 2 and No. 3 according to the heat flow intensity. Reduce the feed rate of methanol-water solution at the feed inlet of the reaction zone and deionized water at the feed inlet of the sweeping zone to ensure that the raw material per unit volume can obtain sufficient heat and ensure the full progress of the methanol steam reforming reaction. After the solar heat flow intensity recovers to the set threshold, gradually increase the feed rate to the standard operating conditions.

[0049] 4. Start the solar coupling heating unit, track the sun and collect solar energy through the trough solar collector, focus it and absorb it through the heat absorption tube and transfer it to the reaction area, so that the temperature of the reaction area rises to the range of 280-320℃ required for the methanol vapor reforming reaction. 5. After the methanol-water solution enters the reaction zone, it undergoes methanol steam reforming and water-gas shift reaction under the action of Cu-based Al2O3-ZnO methanol steam reforming catalyst, generating hydrogen, carbon dioxide, carbon monoxide and a small amount of unreacted raw materials. During the reaction, the modified hydrotalcite-based carbon dioxide adsorbent selectively adsorbs the generated carbon dioxide, driving the reaction from methanol and water to hydrogen and carbon dioxide in the forward direction.

[0050] 6. Water vapor is introduced into the swept area of ​​the hydrogen permeation membrane. Based on the hydrogen partial pressure difference on both sides of the membrane, the hydrogen generated by the reaction quickly and selectively permeates into the swept area, forming a mixture with water vapor. After condensation, hydrogen with a purity of ≥99.9% is obtained. Unpermeated impurity gases and unreacted raw materials are discharged from the reaction zone outlet and can be recycled later.

[0051] 7. During system operation, parameters such as reaction zone temperature, raw material feed flow rate, hydrogen purity, and mass fraction of each substance at the reaction zone outlet are monitored in real time. The elevation angle of the trough solar collector is adjusted according to changes in solar irradiance to maintain a stable reaction temperature.

[0052] 8. When the system has accumulated 72 to 96 hours of operation, or when the carbon dioxide adsorption efficiency is detected to drop below the threshold, switch to regeneration mode. By slightly increasing the temperature of the reaction zone by 300°C to 350°C and introducing a reducing gas, such as CO, the adsorbent desorbs carbon dioxide. The desorbed carbon dioxide can be collected and processed. After regeneration is completed, the system automatically resumes hydrogen production operation.

[0053] 9. When the system stops running, first close the valve of the raw material delivery pipeline to stop the raw material supply; continue to run the solar-coupled heating unit for 5-10 minutes, and after the remaining raw materials in the reaction area have fully reacted, turn off the solar-coupled heating unit by detecting the methanol concentration at the outlet of the reaction area; finally, purge the system with nitrogen to remove residual gas and prevent catalyst oxidation and membrane module contamination. After the system temperature drops to room temperature, turn off all equipment.

[0054] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0055] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A hydrogen separation and CO2 adsorption synergistically enhanced solar methanol reforming hydrogen production system, characterized in that, The application relates to a membrane-adsorption coupling reaction separation unit which adopts an integrated reactor, the reactor is sequentially provided with a glass tube (32), a heat absorption tube (33) and a hydrogen permeation membrane (34) from outside to inside, the glass tube (32), the heat absorption tube (33) and the hydrogen permeation membrane (34) are sealingly connected, a vacuum area is arranged between the glass tube (32) and the heat absorption tube (33), both sides of the reactor are sealingly connected through sealing assemblies, one side of the area between the heat absorption tube (33) and the hydrogen permeation membrane (34) is connected with a pretreated methanol-water solution, and the other side is provided with a discharge port, one side of the internal area of the hydrogen permeation membrane (34) is connected with water vapor, and the other side is provided with a discharge port, and the reactor is installed on a solar energy coupling heating unit.

2. The hydrogen separation and CO2 adsorption synergistically enhanced solar methanol reforming hydrogen generation system according to claim 1, characterized in that, The solar energy coupling heating unit comprises a trough type solar energy collector (21), a plurality of beams are uniformly and parallelly arranged on the trough type solar energy collector (21), the plurality of beams are fixed through two longitudinal beams, the longitudinal beams are perpendicular to the beams, a plurality of beam fixing seats (55) are arranged on the longitudinal beams, the plurality of beams are fixed through the plurality of beam fixing seats (55), each beam is connected with an A-shaped support combination, the vertexes of the plurality of A-shaped support combinations are located on a unified horizontal line, and the reactor is fixedly installed on the connecting line of the vertexes of the plurality of A-shaped support combinations.

3. The hydrogen production system of claim 2, wherein the system further comprises a CO2 adsorption unit. The lower ends of the A-shaped support combinations are fixedly connected with the corresponding beams through the beam fixing seats (55), and the upper ends are fixed with the reactor through U-shaped support frames (48).

4. The hydrogen separation and CO2 adsorption synergistically enhanced solar methanol reforming hydrogen generation system according to claim 2, characterized in that, The trough type solar energy collector (21) adopts a parabolic surface design, and the elevation angle of the trough type solar energy collector (21) can be adjusted in the range of 30-60 degrees.

5. The hydrogen separation and CO2 adsorption synergistic enhanced solar methanol reforming hydrogen production system according to claim 1, characterized in that, The area between the heat absorption tube (33) and the hydrogen permeation membrane (34) is filled with a Cu-based Al2O3-ZnO methanol steam reforming hydrogen catalyst and a modified hydrotalcite-based carbon dioxide adsorbent mixture.

6. The hydrogen separation and CO2 adsorption synergistic enhanced solar methanol reforming hydrogen production system according to claim 1, characterized in that, The hydrogen permeation membrane (34) is coaxially arranged in the heat absorption tube, and the membrane material is a palladium-silver alloy.

7. The hydrogen separation and CO2 adsorption synergistic enhanced solar methanol reforming hydrogen production system according to claim 1, characterized in that, The inner diameter of the glass tube (32) is 1.5-2.0 times that of the heat absorption tube (33), and the inner diameter of the hydrogen permeation membrane (34) is 0.4-0.6 times that of the heat absorption tube (33).

8. The hydrogen separation and CO2 adsorption synergistic enhanced solar methanol reforming hydrogen production system according to claim 1, characterized in that, The water vapor and the methanol-water solution are provided through a raw material pretreatment unit, the raw material pretreatment unit comprises a methanol storage tank (8) and a deionized water storage tank (7), the deionized water storage tank (7) outputs two-way deionized water which enters a first preheater (3) and a raw material mixer (11) respectively, the deionized water of the first preheater (3) is heated and then input into the internal area of the hydrogen permeation membrane (34), the methanol storage tank (8) outputs methanol to the raw material mixer (11), the methanol and the deionized water are mixed to form a methanol-water solution which is then input into a second preheater (13), and the methanol-water solution is heated and then input into the area between the heat absorption tube (33) and the hydrogen permeation membrane (34).

9. The hydrogen separation and CO2 adsorption synergistically reinforced solar methanol reforming hydrogen generation system according to claim 8, characterized in that, The molar ratio of methanol to deionized water in the methanol-water solution is 1:1.1-1:2.

0.

10. The hydrogen separation and CO2 adsorption synergistic enhanced solar methanol reforming hydrogen production system according to claim 1, characterized in that, The U-shaped support (35) is uniformly arranged on the heat absorption pipe, and a support is connected to the U-shaped support (35), and the other end of the support supports the hydrogen gas permeation membrane (34).

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