Carrier, manufacturing method thereof and methanol-to-hydrogen equipment

Abstract

The invention provides a carrier, a manufacturing method thereof and methanol-to-hydrogen equipment. The carrier comprises a three-dimensional net-shaped base body which is formed by weaving metal wires and is overlapped in multiple layers; the reticular matrix has a gradient pore distribution structure of which the porosity is gradually reduced from inside to outside, and the change range of the porosity is 80-90%; the temperature difference of the carrier is reduced, the reaction uniformity is ensured, and the reaction efficiency of the catalyst is improved through the multi-layer overlapped three-dimensional net-shaped matrix formed by weaving the metal wires and the gradient pore distribution design of the carrier; the high porosity is maintained, the specific surface area is optimized, the permeability is enhanced, the unit hydrogen production amount is increased, the coating amount of the catalyst is reduced, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production, in particular to a carrier and a manufacturing method thereof, and a methanol hydrogen production device. BACKGROUND

[0002] Current catalytic reaction carriers mainly use metal honeycomb, ceramic honeycomb (such as cordierite) or alumina particles, which have uniform porosity distribution and strong structural rigidity. As shown in experimental data, although the metal honeycomb carrier (porosity 80%) has a high specific surface area (0.0451 m2), the cross-sectional temperature difference is as high as 80-85℃, which seriously affects the uniformity of the reaction. This contradiction of "high temperature difference-low efficiency" restricts the development of strong exothermic reactions such as hydrogen production.

[0003] In order to solve the above technical problems, the existing technology attempts to improve the porosity gradient as follows: 1. In the prior art, the prior art proposes to realize gradient by changing the honeycomb pore diameter, but due to the limitation of the overall structural rigidity, the porosity adjustment range is only 65-75%, and the processing cost is high.

[0004] 2. In the prior art, although the alumina small ball has a small temperature difference, it has a risk of pulverization and poor fluid disturbance effect.

[0005] 3. Although the metal wire woven carrier can adjust the porosity by adjusting the number of layers, the homogeneous structure formed by the traditional process leads to uneven fluid distribution, and experiments show that the temperature difference is as high as 40-45℃. More importantly, the prior art does not realize the influence of the porosity gradient direction on the reaction efficiency - when the fluid diffuses from the inside to the outside, the uniform porosity structure will aggravate the temperature difference at the outer edge due to the accumulation of reaction heat, which is the fundamental reason for the large temperature difference of the carrier.

[0006] The disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present patent application, nor does it necessarily provide technical teaching; there is no clear evidence that the above-mentioned novelty and inventiveness of the present application. SUMMARY

[0007] In order to solve the above technical problems, the present application proposes a carrier and a manufacturing method thereof, and a methanol hydrogen production device, which reduces the temperature difference of the carrier by forming a three-dimensional mesh matrix with multiple layers of superimposed metal wires and designing the gradient porosity distribution of the carrier, ensures the uniformity of the reaction, and improves the catalyst reaction efficiency; while maintaining high porosity, the specific surface area is optimized and the permeability is enhanced, which not only improves the unit hydrogen production, but also reduces the coating amount of the catalyst and the production cost.

[0008] In order to achieve the above purpose, the technical scheme of the present application is as follows: In one aspect, the application provides a carrier, comprising: a three-dimensional mesh matrix formed by weaving metal wires in multiple layers; The mesh matrix has a gradient pore distribution structure with a gradually decreasing porosity from inside to outside, and the porosity ranges from 80% to 90%.

[0009] The application provides a carrier and a manufacturing method thereof, and a methanol-to-hydrogen device. The three-dimensional mesh matrix formed by weaving metal wires in multiple layers and the gradient pore distribution design of the carrier reduce the temperature difference of the carrier, ensure the uniformity of the reaction, and improve the reaction efficiency of the catalyst. While maintaining high porosity, the specific surface area is optimized and the permeability is enhanced, which not only improves the unit hydrogen production amount, but also reduces the coating amount of the catalyst and the production cost.

[0010] As a preferred technical solution, the weaving includes plain weaving and / or twill weaving, and the weaving angle is 30-60°. The mesh area of the mesh matrix is 4-100mm 2 , and the mesh cross section is square or rhombic. The wire diameter of the metal wire is 0.2-0.5mm, and the metal wire is an iron-chromium-aluminum alloy wire.

[0011] As a preferred technical solution, the three-dimensional mesh matrix has a cylindrical structure, the cross-sectional diameter of the cylindrical structure is φ10-120mm, the axial length is 10-60mm, and the cylindrical structure is formed by spiral winding 2-25 turns.

[0012] As a preferred technical solution, the carrier has a solid structure. And / or the carrier has a hollow structure, and the hollow part of the hollow structure has a cross-sectional diameter of φ2-30mm.

[0013] As a preferred technical solution, the carrier surface is loaded with a methanol-to-hydrogen catalyst coating, and the thickness of the methanol-to-hydrogen catalyst coating is 8-15μm.

[0014] In another aspect, the application provides a manufacturing method of a carrier, which manufactures the carrier as described above, and comprises the following steps: S1 weaving metal wires to form a metal wire mesh; S2 folding the metal wire mesh to form a folded metal wire mesh; S3 winding the folded metal wire mesh into a three-dimensional mesh matrix with a gradient pore distribution under the condition of a dynamically increasing tension force.

[0015] As a preferred technical solution, the dynamically increasing tension force in step S3 ranges from 5N to 15N, and the gradient increment of the dynamically increasing tension force does not exceed 2N / m. The three-dimensional reticular matrix with the gradient pore distribution manufactured through the step S3 is subjected to heat treatment to make the surface layer of the matrix phase change and form a transition layer with enhanced bonding force with the methanol-to-hydrogen catalyst coating, and the heat treatment comprises the following steps: annealing treatment at a temperature of 700-800 ℃ for 1.5-2.5 hours.

[0016] In still another aspect, the application further provides a methanol-to-hydrogen device, comprising: a reaction tube and a carrier as described above assembled in the reaction tube.

[0017] As a preferred technical solution, a plurality of the carriers are assembled along the axial direction of the reaction tube, and the outermost metal mesh porosity of the carrier is less than the outermost metal mesh porosity of the adjacent carrier.

[0018] As a preferred technical solution, a blank carrier without the methanol-to-hydrogen catalyst coating is arranged at the reactant inlet side of the reaction tube.

[0019] The application provides a carrier, a manufacturing method thereof and a methanol-to-hydrogen device, which have the following beneficial effects: 1) The application provides a carrier, a manufacturing method thereof and a methanol-to-hydrogen device, which reduce the temperature difference of the carrier, ensure the reaction uniformity and improve the catalyst reaction efficiency through the three-dimensional reticular matrix formed by wire weaving and the gradient pore distribution design of the carrier; the specific hydrogen production amount is improved, the catalyst coating amount is reduced and the production cost is reduced while the high porosity, the optimized specific surface area and the enhanced permeability are maintained.

[0020] 2) The application provides a carrier, a manufacturing method thereof and a methanol-to-hydrogen device, which make the reactant permeate from the outside to the inside: the outer dense structure quickly conducts heat to avoid edge heat accumulation; the high-porosity inner layer increases the reaction contact area and reduces the risk of local overheating, optimizes the heat conduction channel of the carrier, solves the fundamental problem of the large cross-sectional temperature difference of the traditional carrier, ensures the reaction uniformity and improves the catalyst reaction efficiency. Through the design of the three-dimensional reticular matrix formed by wire weaving, the specific surface area is optimized while the high porosity (80-90%) is maintained, the permeability is improved, the specific hydrogen production amount is improved, the catalyst coating amount is reduced and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 FIG. 1 is a structural schematic diagram of a carrier (solid structure) provided by the application; Figure 2 FIG. 2 is a partially expanded structural schematic diagram of a carrier (solid structure) provided by the application; Figure 3 A structural schematic diagram from another perspective of a carrier (solid structure) provided by the present invention; Figure 4 A schematic diagram of the structure of a carrier provided by the present invention from another perspective; Figure 5 A schematic diagram of a carrier (hollow structure) provided by the present invention; Figure 6 This is a schematic diagram of a methanol-to-hydrogen device provided by the present invention; Among them, 1-carrier; 2-mesh; 3-metal wire; 4-hollow part; 5-methanol to hydrogen equipment; 6-reaction tube. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] like Figures 1-5 As shown, the present invention provides a carrier comprising: a three-dimensional mesh matrix formed by weaving metal wires into multiple layers; The mesh matrix has a gradient pore distribution structure with porosity gradually decreasing from the inside to the outside, and the porosity ranges from 80-90%.

[0024] This invention proposes a carrier that uses a multi-layered, three-dimensional mesh matrix formed by weaving metal wires and a gradient pore distribution design to reduce the temperature difference of the carrier, ensure reaction uniformity, and improve catalyst reaction efficiency. While maintaining high porosity, the optimized specific surface area and enhanced permeability not only increase the unit hydrogen production but also reduce the amount of catalyst coating, thereby reducing production costs.

[0025] Preferably, such as Figures 1-5 As shown, the weaving includes plain weave and / or twill weave, and the weaving angle is 30-60°. The preferred weaving angle is 30°, 45° or 60°. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the scope of protection. The mesh area of ​​the mesh substrate is 4-100 mm². 2 The cross-section of the mesh 2 is square or rhomboid, and the area of ​​the mesh 2 of the mesh substrate is preferably 4 mm. 2 52 mm 2 Or 100mm 2 Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the scope of protection. The diameter of the metal wire 3 is 0.2-0.5 mm. The metal wire 3 is an iron-chromium-aluminum alloy wire. The preferred diameter of the metal wire 3 is 0.2 mm, 0.25 mm, 0.35 mm or 0.5 mm. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection. Preferably, the metal wire 3 is plain woven: the warp and weft wires interweave once every other wire to form a dense interlacing structure, providing high surface flatness and uniform pore distribution, enhancing the uniformity of reactant diffusion; at the same time, its high air permeability facilitates rapid heat transfer and avoids the formation of local hot spots; Preferably, the metal wire 3 is twill woven: the warp and weft wires interweave at least every two wires (e.g., 2 up 1 down or 3 up 1 down) to form a twill pattern, making the structure denser and thicker, improving wear resistance and mechanical strength; under high temperature conditions, it can effectively resist thermal stress deformation and extend the service life of the carrier; The weaving angle is 30-60°, and the weaving is diagonally interwoven at a certain angle. Heat is evenly diffused along the diagonal path, reducing temperature fluctuations, maintaining the optimal activity temperature window of the catalyst, buffering external force impacts, reducing the risk of crack propagation, and improving shock resistance. The mesh area of ​​the mesh matrix is ​​preferably 4-100 mm. 2 The range balances diffusion efficiency and mechanical strength; small mesh area increases surface area and improves catalyst loading; large mesh area optimizes fluid permeability, reduces pressure drop, and ensures that reactants fully contact active sites. The preferred cross-section of the mesh 2 is a square cross-section: it is adapted to plain weave, provides uniform flow channels, reduces flow dead angles, promotes uniform distribution of reactants, optimizes pore utilization efficiency, and improves mass transfer performance per unit area. The preferred cross-section of the mesh 2 is a rhomboid cross-section: it is adapted to twill weave, uses an asymmetric structure to guide turbulence, enhances the local mass transfer rate, inhibits carbon buildup and blockage, optimizes pore utilization efficiency, and improves the mass transfer performance per unit area. The wire diameter of metal wire 3 is preferably 0.2-0.5 mm. Within this range, the optimal balance between surface area and strength is achieved, which improves the thermal fatigue life of the support and maintains a high reaction rate. A finer wire diameter is preferred to increase the specific surface area and increase the density of active sites of the catalyst; a thicker wire diameter strengthens the structural rigidity and resists thermal expansion deformation. The preferred metal wire is an iron-chromium-aluminum alloy wire, which is an electrothermal material with iron, chromium and aluminum as the main components. It has the characteristics of high resistivity, small temperature coefficient of resistance, good oxidation resistance and high operating temperature. Its maximum operating temperature can reach 1400℃. This alloy is lightweight, low cost and does not have the problem of high temperature brittleness.

[0026] Preferably, such as Figures 1-5As shown, the three-dimensional mesh matrix has a cylindrical structure with a cross-sectional diameter of φ10-120mm and an axial length of 10-60mm, and is formed by spiral winding 2-25 times. The cross-sectional diameter of the cylindrical structure is preferably φ10mm, φ65mm or φ120mm. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the scope of protection. The axial length of the cylindrical structure is preferably 10mm, 35mm or 60mm. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the scope of protection. The number of spiral turns of the cylindrical structure is preferably 2, 13 or 25. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the scope of protection. The cylindrical structure provides a symmetrical heat flow path, uniformly distributing heat and further reducing internal temperature differences (compressible to within ±5°C), which stems from its geometric symmetry offsetting local expansion stress. The preferred diameter of the cylindrical structure cross-section is φ10-120mm, and the diameter range (φ10-120mm) is suitable for reactors of different sizes. Axial length (10-60mm) controls heat gradient transfer: shorter length reduces the risk of axial temperature difference, while longer length extends the reaction residence time and improves conversion rate; The cylindrical structure forms a continuous interlocking structure by spiraling 2-25 times, which enhances its resistance to thermal fatigue.

[0027] Preferably, the carrier 1 is a solid structure (e.g., Figures 1-4 (as shown) And / or the carrier 1 is a hollow structure (e.g. Figures 4-5 As shown in the figure, the diameter of the hollow part of the hollow structure is φ2-30mm. As the diameter of reaction tube 6 increases, the temperature difference across the cross section becomes more pronounced, to the point that the temperature in a certain range at the center of support 1 approaches or falls below the lower limit of the optimal reaction temperature range for the catalyst, resulting in low reaction efficiency or no reaction at the center. The catalyst coated in this part is an ineffective catalyst. By removing the central part of the support, a hollow structure is obtained, reducing the amount of catalyst used and lowering production costs. Preferably, such as Figures 1-4 As shown, the diameter of the solid structure carrier 1 is preferably 10-30 mm. The diameter of the solid structure carrier 1 is preferably 10 mm, 20 mm or 30 mm. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the scope of protection. like Figures 4-5The diameter of the hollow carrier 1 shown is preferably 30-120 mm. The diameter of the hollow carrier 1 is preferably 30 mm, 75 mm or 120 mm. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection.

[0028] Preferably, such as Figures 1-5 As shown, the surface of the carrier 1 is loaded with a methanol-to-hydrogen catalyst coating, the thickness of which is 8-15 μm; preferably, the thickness of the methanol-to-hydrogen catalyst coating is 8 μm, 12 μm, or 15 μm. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection. An appropriate thickness ensures sufficient contact between the reactant gas and the catalyst, while avoiding internal diffusion restriction due to excessive thickness, thus effectively reducing the amount of catalyst coating while meeting the hydrogen production efficiency requirements.

[0029] On the other hand, the present invention provides a method for manufacturing a carrier, which manufactures the carrier as described above, comprising the following steps: S1 is made of metal wire 3 woven to form a metal wire mesh; S2 folds the metal wire mesh to form a folded metal wire mesh; S3 winds the folded metal wire mesh into a three-dimensional mesh matrix with a gradient pore distribution under dynamically increasing tension.

[0030] This invention proposes a methanol-to-hydrogen device. By using a multi-layered, three-dimensional mesh matrix formed by weaving metal wires and a gradient pore distribution design on the carrier, the temperature difference of the carrier is reduced, ensuring reaction uniformity and improving catalyst reaction efficiency. While maintaining high porosity, the optimized specific surface area and enhanced permeability not only increase the unit hydrogen production but also reduce the amount of catalyst coating, thereby reducing production costs.

[0031] Preferably, the following step is included between steps S2 and S3: Cutting steps: Cut the wire mesh into individual mesh pieces with a length of 80-5000mm and a width of 15-150mm; Inspection steps: Conduct quality inspection on the length and width dimensions, mesh parameters, wire diameter, and weight of the mesh sheet; The length of the independent mesh panel is preferably 100mm, 400mm or 1200mm. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection. The width of the independent mesh panel is preferably 20mm, 50mm or 100mm. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection. Preferably, step S3 further includes the following steps: Fixing steps: Fix the three-dimensional mesh matrix with gradient pore distribution by fixing the end of the mesh to the side plate of the carrier through laser welding to obtain the fixed three-dimensional mesh matrix with gradient pore distribution; Shaping steps: Shaping the fixed three-dimensional mesh matrix with gradient pore distribution to control the overall dimensional accuracy of the matrix.

[0032] Preferably, the dynamic increasing tension force in step S3 is in the range of 5-15N, and the gradient increase of the dynamic increasing tension force does not exceed 2N / m; The three-dimensional network matrix with gradient pore distribution obtained in step S3 is subjected to heat treatment to cause a phase change in the surface layer of the matrix, forming a transition layer with enhanced adhesion to the methanol-to-hydrogen catalyst coating. The heat treatment includes the following steps: annealing at 700-800℃ for 1.5-2.5 hours. The preferred temperature for the heat treatment is 700℃, 750℃, or 800℃. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection. The preferred time for the heat treatment is 1.5 hours, 2 hours, or 2.5 hours. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the scope of protection. The three-dimensional mesh material with gradient pore distribution is an iron-chromium-aluminum alloy. The methanol-to-hydrogen catalyst coating is preferably a Pt / In / Al2O3 noble metal catalyst coating. After heat treatment, a transition layer with enhanced adhesion to the methanol-to-hydrogen catalyst coating is formed on the surface of the iron-chromium-aluminum alloy. The transition layer with enhanced adhesion to the methanol-to-hydrogen catalyst coating is preferably an Al2O3 oxide film. The Al2O3 oxide film is the same as the Pt / In / Al2O3 noble metal catalyst substrate, which greatly increases the adhesion between the catalyst coating and the support, effectively reduces the catalyst coating peeling rate, and extends the catalyst service life.

[0033] On the other hand, such as Figure 6 As shown, the present invention also provides a methanol-to-hydrogen apparatus, comprising: a reaction tube 6 and a carrier 1 as described above assembled within the reaction tube 6.

[0034] Preferably, multiple carriers 1 are assembled along the axial direction of the reaction tube 6, such that the porosity of the outermost metal mesh of the carrier 1 is less than the porosity of the outermost metal mesh of the adjacent carrier 1. In actual use, the methanol-to-hydrogen equipment 5 contains one or more reaction tubes 6. Depending on the amount of hydrogen produced, the number of carriers 1 in each reaction tube 6 varies from 1 to 30. As the heat transfer fluid on the heating side transfers heat, the temperature gradually decreases along the flow direction. Inevitably, the heat transfer in the reaction tube 6 gradually decreases from front to back, resulting in a large temperature difference between the front and back of the reaction tube 6.

[0035] Accordingly, to further optimize the effect of temperature difference along the axial direction of the reaction tube 6, more refined specifications are set for the metal wire mesh carrier 1 with the same outer diameter. Specifically, both the solid cylindrical metal wire mesh carrier 1 and the hollow cylindrical metal wire mesh carrier 1 contain 1-5 different specifications of carriers. Along the axial direction of the reaction tube 6, the outermost layer of the metal mesh of the carrier 1 has a gradient step of gradually decreasing porosity, or a gradient step of gradually increasing porosity. Since the mesh matrix has a gradient porosity distribution structure with gradually decreasing porosity from the inside to the outside, the radial cross-section of the reaction tube 6 forms a gradient porosity distribution. The radial cross-section and the axial direction of the reaction tube 6 both form a gradient porosity distribution, thereby solving the problem of the catalyst reaction efficiency being affected by temperature difference in the radial cross-section and the axial direction of the reaction tube 6. For ease of description, the solid wire mesh carrier 1 is distinguished by the porosity of its outermost layer, specifically divided into low-porosity, medium-porosity, and high-porosity wire mesh carriers 1. Similarly, the hollow wire mesh carrier 1 is also distinguished by the porosity of its outermost layer, specifically divided into low-porosity, medium-porosity, and high-porosity hollow wire mesh carriers 1.

[0036] Preferably, a blank carrier without a methanol-to-hydrogen catalyst coating is provided on the hot flue gas inlet side of the reaction tube 6. In addition to the temperature difference issue in the cross-section of the reaction tube, the structural design of the shell-and-tube methanol-to-hydrogen reactor must also be considered. When the heating flue gas enters the shell-side flow channel, it blows directly onto the reaction tube 6 from the end face or the side of the front end of the reaction tube 6. The high-temperature flue gas (400-650℃) at the inlet can easily cause catalyst deactivation at the front end of the reaction tube 6. Correspondingly, a blank carrier without methanol-to-hydrogen catalyst coating is set in the affected area. Similarly, the blank carrier without methanol-to-hydrogen catalyst coating is also divided into two forms: solid and hollow.

[0037] Therefore, in the specific methanol-to-hydrogen reaction tube 6, the preferred combination of carriers is: a blank solid carrier without a methanol-to-hydrogen catalyst coating + a solid carrier with low outermost metal mesh porosity + a solid carrier with high outermost metal mesh porosity + a solid carrier with high outermost metal mesh porosity. The same principle applies to the distribution of hollow metal wire mesh carriers in methanol-to-hydrogen equipment with large hydrogen production capacity. It should be noted that the specific carriers with low outermost metal mesh porosity, high outermost metal mesh porosity, and high outermost metal mesh porosity are not necessarily arranged in the same quantity within the reaction tube 6; the specific arrangement depends on the actual temperature distribution of each reaction tube 6.

[0038] Compared to using a carrier of the same specifications, the above arrangement method maintains high catalyst activity and efficiency while effectively reducing the amount of catalyst used. It also effectively avoids incomplete reactions and the generation of side reaction products due to temperature differences.

[0039] Additionally, for methanol-to-hydrogen equipment 5 with a large hydrogen production capacity, such as a hydrogen production capacity greater than 50 Nm³, 3 / h, often multiple sets of reaction tubes 6 are distributed in parallel within the methanol to hydrogen equipment 5, and there will also be temperature differences in the cross-sectional direction of the methanol to hydrogen equipment 5 itself. Different combinations of carriers 1 can also be used for the reaction tubes 6 in different areas according to the temperature distribution trend.

[0040] Example 1 like Figures 1-5 As shown, the present invention provides a carrier comprising: a three-dimensional mesh matrix formed by weaving metal wires into multiple layers; The diameter of the carrier 1 is 20 mm; The metal wire 3 is made of iron-chromium-aluminum alloy (grade 0Cr25AL5). The metal wire 3 has a diameter of 0.25 mm, a weaving angle of 30°, and a mesh area of ​​6 mm². 2 After molding, the carrier has a cylindrical structure with a cross-sectional diameter of 12 mm and a length of 20 mm. The carrier has a gradient pore distribution with a porosity that gradually decreases from 90% in the inside to 80% in the outside. The number of spiral windings is 5.5. The surface of the carrier is loaded with a methanol-to-hydrogen catalyst coating with a thickness of 12 μm. The methanol-to-hydrogen catalyst is preferably Pt / In / Al2O3. The preparation process of the above-mentioned carrier is as follows: Weaving: A metal wire braiding machine is used, set to twill weave, unidirectional corrugation, and a weaving angle of 30°, to weave 0.25mm diameter iron-chromium-aluminum alloy wires to form a metal wire mesh; Cutting: Cut the wire mesh into individual mesh sheets, each 115m long and 40mm wide; Inspection: The main inspections include the length and width dimensions, mesh size, wire diameter, and weight of the cut wire mesh. Folding: The inspected and qualified mesh sheet is folded using a bending machine. In the width direction of the mesh sheet, both sides are folded towards the central axis, resulting in a mesh sheet with a length of 115mm, a width of 20mm, and an overall thickness of 0.95mm. Leveling: The qualified wire mesh is leveled and the edges are trimmed; Winding: The flattened mesh is loaded into the winding equipment. The winding equipment has a special fixing fixture, which includes a winding-side clamping head and a tensioning-side clamping head. The winding-side clamping head rotates around an axis to wind the mesh into a cylindrical carrier. The tensioning-side clamping head provides tension force. During the winding process, the tension force increases uniformly within a set range of 5-15N, and the gradient increase of the dynamically increasing tension force does not exceed 2N / m, ensuring that the metal wire mesh carrier after winding meets the requirements. After winding, the clamping head is used to fix it. Welding: Laser welding is used to fix the tail end of the mesh to the side plate of the carrier to prevent it from spreading out; Shaping: Shaping the wound carrier to control the dimensional accuracy of the metal wire mesh carrier; Heat treatment: The carrier is annealed at 750℃ for 2 hours to relieve stress and enhance surface activity; Catalyst coating: A methanol-to-hydrogen catalyst coating is applied to the surface of the support so that the methanol-to-hydrogen catalyst coating is loaded onto the surface of the support.

[0041] Example 2 The rest is the same as in Example 1, except for the winding step: the flattened mesh is loaded into the winding device, which has a special fixing fixture. The fixture includes a winding-side clamping head and a tensioning-side clamping head. The winding-side clamping head rotates around an axis to wind the mesh into a cylindrical carrier. The tensioning-side clamping head provides tension force. During the winding process, the preset tension force is constant at 4N, so that the porosity of the carrier is constant at 91%.

[0042] Example 3 The rest is the same as in Example 1, except for the winding step: the flattened mesh is loaded into the winding device, which has a special fixing fixture. The fixture includes a winding-side clamping head and a tensioning-side clamping head. The winding-side clamping head rotates around an axis to wind the mesh into a cylindrical carrier. The tensioning-side clamping head provides tension. During the winding process, the preset tension is constant at 16N, so that the porosity of the carrier is constant at 78%.

[0043] Performance Test 1 Different carrier forms were loaded into the same single-tube reactor with an inner diameter of 20 mm. The same heating and control conditions were used. Specific carrier parameters and performance test results are shown in the table below. The carrier forms used for comparison were alumina microsphere carriers, metal honeycomb carriers, and metal wire mesh carriers (Examples 1-3 of this application). The metal wire mesh carriers and metal honeycomb carriers in Examples 1-3 of this application were both φ20*20 mm in size. Conventional φ4 mm alumina microspheres were used. Three sets of different specifications of the metal wire mesh carriers in Examples 1-3 were set up for comparison. The three sets of metal wire mesh carriers were selected based on porosities >90%, 80-90%, and <80%, respectively. The metal honeycomb carriers used a specification with an inner wall material thickness of 0.1 mm. The number of metal wire mesh carriers and metal honeycomb carriers in Examples 1-3 was one. The alumina microsphere carrier was loaded to a height of 20 mm. The metal wire mesh carriers, metal honeycomb carriers, and alumina microsphere carriers in Examples 1-3 of this application were tested using the following experimental methods: Dimensions and weight: Measured directly using vernier calipers (accuracy 0.02mm) and an electronic balance (accuracy 0.001g); Porosity: tested using μ-CT nondestructive testing (ZEISS Xradia 620 Versa); Catalyst coating amount: measured using X-ray fluorescence spectroscopy (XRF); Maximum hydrogen production per unit volume: The hydrogen production capacity was tested according to GB / T 24460-2009 "Test Method for Activity of Methanol Steam Reforming Hydrogen Production Catalysts". Maximum temperature difference test of cross section: The temperature distribution of the cross section is monitored by placing temperature sensors in the cross section area; The experimental data obtained from testing the metal wire mesh carrier, metal honeycomb carrier, and alumina microsphere carrier in Examples 1-3 are shown in Table 1 below: Table 1. Performance test data of metal wire mesh carrier, metal honeycomb carrier, and alumina microsphere carrier in Examples 1-3 of the application. From Table 1, we can observe that Example 2 can effectively reduce the cross-sectional temperature difference, but the constant large porosity of the support causes the flow rate to be too fast, and the hydrogen production efficiency is not high. Example 3 has the highest hydrogen production per unit volume, but due to the constant small porosity of the support, obvious agglomeration has occurred in the actual in-body catalyst coating. The corresponding increase in catalyst dosage is not proportional to the increase in hydrogen production. The metal honeycomb support has the largest surface area and the largest amount of catalyst coating. However, due to its internal straight-through flow channel, the flow rate is fast and the effective contact time between reactants and catalyst is short. When the temperature difference of the metal honeycomb support is as high as 80-85℃, the hydrogen production is only 7.78g / h. The alumina microsphere support has a significant advantage in terms of weight and the temperature difference in the cross-section is relatively small. Although the surface area is much lower than other comparative groups, due to the microporous structure of its surface, the actual amount of catalyst is not low. However, the spherical structure does not have a high actual disturbance effect on the fluid. In addition, the hydrogen production of alumina microspheres at a temperature difference of 25-30℃ (10.13g / h) is still limited by the microporous structure. Example 1 of this application, through a gradient pore design (80-90% dynamic variation), enables the support to achieve a hydrogen production rate of 12.67 g / h with a catalyst coating amount of 0.2 g and a surface area of ​​0.018 m², while controlling the temperature difference at 35-40 °C. This is significantly superior to the comparative groups (Examples 2-3, metal honeycomb support, and alumina microsphere support). The support provided in Example 1 of this application avoids the excessively high flow rate caused by high porosity (the problem of the support in Example 2) and solves the catalyst accumulation caused by low porosity (Example 3).

[0044] Performance Test 2 Performance comparison of different combinations with the same filling volume, mainly focusing on different combinations of metal wire mesh carriers: The experimental setup consisted of three carriers. Two carriers, 4 and 5, were introduced, both with dimensions of φ20*20. Carrier 4 weighed 6g, and the porosity of its outermost metal mesh was 86%. Carrier 5 weighed 7g, and the porosity of its outermost metal mesh was 84%. The setup was divided into two groups. The first group consisted of three identical carriers obtained in Example 2 of this application assembled into the reaction tube 6. The second group consisted of the reaction tube 6 sequentially assembled from the front end with the carriers obtained in Example 2, carrier 4, and carrier 5. Using the same heating and control conditions, the specific parameters and performance of the combined carriers were tested using the experimental methods described in Performance Test 1 above. The test results are shown in Table 2 below. Table 2. Experimental data on parameters and performance tests of the combined carrier. Results show that the experimental termination trigger condition is when the methanol content in the generated gas is greater than 100 ppm. The methanol inlet volume of the second group is slightly less than that of the first group, with a difference of about 0.9%. The total hydrogen production is very close, with a difference of about 0.94%. Since the difference is less than 1%, it can be considered that the two groups can achieve the same effect. The total weight difference between the two groups is 3g, and the total catalyst coating amount difference is 0.05g, which is a reduction of 8.3%. The carrier adopts the combination method of the second group, which further reduces the amount of catalyst coating and reduces production costs.

[0045] It is understood that this invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of this invention.

Claims

1. A carrier, characterized in that, include: Metal wires are woven to form a multi-layered, three-dimensional mesh matrix; The mesh matrix has a gradient pore distribution structure in which the porosity gradually decreases from the inside to the outside, and the porosity ranges from 80% to 90%.

2. The carrier according to claim 1, characterized in that, The weaving includes plain weave and / or twill weave, wherein the weaving angle is 30-60°; The mesh area of ​​the mesh matrix is ​​4-100 mm. 2 The cross-section of the mesh is square or rhomboid; The diameter of the metal wire is 0.2-0.5 mm, and the metal wire is an iron-chromium-aluminum alloy wire.

3. The carrier according to claim 1, characterized in that, The three-dimensional mesh matrix has a cylindrical structure with a cross-sectional diameter of φ10-120mm and an axial length of 10-60mm, and is formed by spiral winding 2-25 times.

4. The carrier according to claim 1, characterized in that, The carrier is a solid structure; And / or the carrier is a hollow structure, and the cross-sectional diameter of the hollow part of the hollow structure is φ2-30mm.

5. The carrier according to claim 1, characterized in that, The surface of the carrier is loaded with a methanol-to-hydrogen catalyst coating, the thickness of which is 8-15 μm.

6. A method for manufacturing a carrier, characterized in that, Manufacturing the carrier as described in claim 1 includes the following steps: S1 uses metal wire weaving to form a metal wire mesh; S2 folds the metal wire mesh to form a folded metal wire mesh; S3 winds the folded metal wire mesh into a three-dimensional mesh matrix with a gradient pore distribution under dynamically increasing tension.

7. The method for manufacturing the carrier according to claim 6, characterized in that, The dynamic increasing tension force in step S3 is in the range of 5-15N, and the gradient increase of the dynamic increasing tension force does not exceed 2N / m. The three-dimensional network matrix with gradient pore distribution obtained in step S3 is subjected to heat treatment to cause a phase change in the surface layer of the matrix, forming a transition layer with enhanced adhesion to the methanol-to-hydrogen catalyst coating. The heat treatment includes the following steps: Annealing is performed at 700-800℃ for 1.5-2.5 hours.

8. A methanol-to-hydrogen apparatus, characterized in that, Includes: a reaction tube and a carrier as described in claim 1 assembled within the reaction tube.

9. The methanol-to-hydrogen equipment according to claim 8, characterized in that, Multiple carriers are assembled along the axial direction of the reaction tube such that the porosity of the outermost metal mesh of the carrier is less than that of the outermost metal mesh of the adjacent carrier.

10. The methanol-to-hydrogen equipment according to claim 8, characterized in that, A blank carrier without a methanol-to-hydrogen catalyst coating is provided on the reactant inlet side of the reaction tube.

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