A device for producing high-purity hydrogen

Abstract

This invention discloses a high-purity hydrogen production device, comprising: an evaporation module, a reforming module, and a purification module; the temperature of the medium within the evaporation module, reforming module, and purification module gradually increases, and heat from the high-temperature module can be transferred to the low-temperature module; the evaporation module has multiple heat exchange plates, and a partition is provided between adjacent heat exchange plates, dividing the space between adjacent heat exchange plates into a preheating space and an inflow space; the reforming module has several reforming channel groups, which are connected to the evaporation module by a gradually narrowing channel; the purification module has purification channels, and several hydrogen permeable membranes are provided within the purification channels; the purification channels are connected to the reforming channel groups; the purification module passes sequentially through the reforming module and the evaporation module, so that the purification channels can transfer heat with the reforming module and the evaporation module. This allows for thermal coupling between multiple modules, enabling gradient energy utilization and solving the problems of uneven heating within the reforming reaction chamber.

Description

Technical Field

[0001] This invention relates to the field of reforming hydrogen production technology, and in particular to a device for producing high-purity hydrogen. Background Technology

[0002] Methanol is a common and inexpensive chemical raw material with a wide range of sources; moreover, methanol has a high hydrogen content, and the production of hydrogen through methanol catalytic reforming can support the direct use of hydrogen in energy equipment such as fuel cells, avoiding the problems of hydrogen transportation and storage.

[0003] The temperature of a large amount of industrial waste heat is 200-400 degrees Celsius. This temperature range can provide sufficient thermodynamic conditions for methanol reforming. Therefore, using industrial waste heat to produce hydrogen from methanol reforming can reduce energy consumption in the hydrogen production process and achieve the goal of energy conservation.

[0004] Currently, methanol reforming for hydrogen production technology is widely used in energy equipment such as fuel cells. Its core modules consist of three parts: an evaporation module, a methanol reforming module, and a hydrogen purification module. The reformer structures include tubular, plate, and microchannel types. Tubular and plate reformers commonly suffer from uneven reforming temperatures within the reforming chamber, leading to hot spots. Furthermore, the low integration of the core modules in methanol catalytic reforming results in a significant waste of high-quality energy. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an apparatus for producing high-purity hydrogen using industrial waste heat, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0006] The solution to the technical problem of this invention is:

[0007] A high-purity hydrogen preparation apparatus, characterized in that it comprises: an evaporation module, a reforming module, and a purification module;

[0008] The purification module passes through the reforming module and the evaporation module in sequence. The evaporation module can transfer heat with the reforming module and the purification module, so that the evaporation module can use the waste heat of the reforming module and the purification module to evaporate the material.

[0009] The gas in the purification module flows countercurrently to the gas in the evaporation module and the reforming module; the purification module is provided with a purification channel, and the purification channel is provided with several hydrogen selective permeation membranes.

[0010] The reforming module is equipped with several parallel reforming channel groups. The inlet of the reforming channel group is connected to the evaporation module through a converging channel, and the outlet of the reforming channel group is connected to the purification channel through a pressure controller. The converging channel is used to increase the pressure difference between the gas and the back pressure, provide additional power for gas flow, increase the gas flow rate, and reduce the gas pressure to increase hydrogen production.

[0011] The above technical solution can realize the thermal coupling of heat conduction and convection heat transfer among the purification module, reforming module and evaporation module, so as to achieve the purpose of energy gradient utilization. At the same time, it can also solve the shortcomings and defects such as uneven heating in the reforming reaction chamber, which leads to increased by-product generation and reduced reforming catalytic reaction efficiency to a certain extent.

[0012] As a further improvement to the above technical solution, the reforming channel group is further provided with a catalyst pre-positioning tank, a first reforming channel and a second reforming channel. The catalyst pre-positioning tank is connected to the lower end of the first reforming channel, and the upper end of the second reforming channel is provided with a second arc-shaped corner section. The catalyst pre-positioning tank is connected to the second arc-shaped corner section.

[0013] The above technical solution uses a catalyst pre-positioning tank to hold the catalyst, thus preventing it from falling into the evaporation module.

[0014] As a further improvement to the above technical solution, it also includes a first heating device, which is disposed between the first reforming pipeline and the purification channel; it also includes a waste heat exchange module, which is provided with a high-temperature gas channel and a heat exchange mounting cavity, and the reforming module and the evaporation module are both installed in the heat exchange mounting cavity.

[0015] Through the above technical solution, the first heating device provides additional thermal conditions for purification and reforming. By setting up a waste heat exchange module, the high-temperature gas generated during the factory production process can enter the waste heat exchange module to provide thermal conditions for the high-purity hydrogen production unit, thereby improving the factory's energy utilization rate and effectively reducing resource waste.

[0016] As a further improvement to the above technical solution, the high-temperature gas channel is spirally coiled around the heat exchange mounting cavity; the gas in the high-temperature gas channel flows sequentially past the side of the reforming module and the side of the evaporation module.

[0017] Through the above technical solution, high-temperature industrial waste gas is introduced into the high-temperature gas channel. The high-temperature industrial waste gas carries a large amount of industrial waste heat. The flow direction of the high-temperature gas is from the side of the reforming module to the side of the evaporation module, which is opposite to the flow direction of hydrogen. This allows the high-temperature gas to fully exchange heat with hydrogen, which is beneficial to improving the heat utilization rate of industrial waste heat.

[0018] As a further improvement to the above technical solution, the evaporation module is provided with multiple heat exchange plates and a pressure sensor; a partition is provided between two adjacent heat exchange plates, the partition dividing the space between the two adjacent heat exchange plates into a preheating space and an inflow space, the partition being used to separate the unpreheated gas from the preheated gas to improve the evaporation efficiency; the pressure sensor is placed at the bottom of the evaporation module.

[0019] Through the above technical solution, the heat from the waste heat exchange module is transferred to the methanol aqueous solution via heat exchange plates. By setting multiple heat exchange plates and multiple first holes, the heating area of ​​the methanol aqueous solution can be increased, so as to better preheat and evaporate the methanol aqueous solution.

[0020] The beneficial effects of this invention are: by utilizing the temperature difference between the working temperatures of different modules, thermal coupling of heat conduction and convection heat transfer is achieved among the purification module, reforming module and evaporation module, so as to achieve the purpose of energy gradient utilization. At the same time, it can also solve the shortcomings and defects such as uneven heating in the reforming reaction chamber, which leads to increased by-product generation and reduced reforming catalytic reaction efficiency.

[0021] This invention relates to the field of hydrogen production through reforming. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly explained below. Obviously, the described drawings are only a part of the embodiments of the present invention, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a half-section structure according to an embodiment of the present invention;

[0024] Figure 2 This is a cross-sectional view of the temperature distribution according to an embodiment of the present invention;

[0025] Figure 3 This is a cross-sectional view of the steam volume fraction distribution according to an embodiment of the present invention;

[0026] Figure 4 This is a cross-sectional view of the pressure distribution according to an embodiment of the present invention.

[0027] In the diagram, 100 is the reforming module; 110 is the third reforming pipeline; 120 is the first reforming pipeline; 130 is the catalyst powder collection tank; 140 is the second reforming pipeline; 150 is the catalyst pre-positioning tank; 200 is the evaporation module; 210 is the raw material inlet; 220 is the heat exchange plate; 221 is the first perforation body; 230 is the partition plate; 300 is the purification module; 310 is the hydrogen permeation membrane; 400 is the waste heat exchange module; 410 is the heat exchange mounting cavity; 420 is the high-temperature gas channel; 401 is the high-temperature gas inlet; 402 is the high-temperature gas outlet; 500 is the first heating device; and 600 is the second heating device. Detailed Implementation

[0028] The following will clearly and completely describe the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Furthermore, all connections / linkages mentioned herein do not simply refer to direct connection of components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0029] Reference Figures 1 to 4 A high-purity hydrogen production device includes: a reforming module 100, an evaporation module 200, a purification module 300, and a waste heat exchange module 400. Heat from the higher-temperature modules can be transferred to the lower-temperature modules through heat conduction and convection.

[0030] The waste heat exchange module 400 is provided with a heat exchange mounting cavity 410 and a high-temperature gas passage 420. The reforming module 100 and the evaporation module 200 are both installed in the heat exchange mounting cavity 410. The reforming module 100, the evaporation module 200, and the purification module 300 are all installed in the heat exchange mounting cavity 410.

[0031] The high-temperature gas channel 420 is provided with a high-temperature gas inlet 401 and a high-temperature gas outlet 402. The high-temperature gas outlet 402 of the high-temperature gas channel 420 is located below the high-temperature gas inlet 401 of the high-temperature gas channel 420.

[0032] The high-temperature gas channel 420 is spirally arranged and coils around the heat exchange mounting cavity 410, so that the gas flowing in the high-temperature gas channel 420 can effectively transfer heat to the heat exchange mounting cavity 410. The side wall of the high-temperature gas channel 420 is provided with through holes.

[0033] By setting up a waste heat exchange module 400, the high-temperature gas generated during the factory production process can enter the waste heat exchange module 400 to provide thermal conditions for the high-purity hydrogen production unit, thereby improving the factory's energy utilization rate and effectively reducing resource waste.

[0034] The evaporation module 200 is provided with a raw material inlet 210, and methanol flows into the evaporation module 200 from the raw material inlet 210.

[0035] The evaporation module 200 includes multiple heat exchange plates 220, which are arranged at equal intervals in the vertical direction. Each heat exchange plate 220 has multiple first holes 221, which are evenly arranged in the heat exchange plate 220 and penetrate the heat exchange plate 220 in the vertical direction.

[0036] Specifically, in this embodiment, the first hole body 221 is arranged in multiple layers of hole groups, and the first hole body 221 of each layer of hole group is arranged in a circular shape. The multiple layers of hole groups are concentrically arranged, and the number of the first hole bodies 221 of the hole groups from the center of the heat exchange plate 220 to the outside of the heat exchange plate 220 is set to 20, 28, 32 and 40 respectively.

[0037] The heat from the waste heat exchange module 400 is transferred to the methanol aqueous solution via the heat exchange plates 220. By setting multiple heat exchange plates 220 and multiple first holes 221, the heating area of ​​the methanol aqueous solution can be increased to better preheat and evaporate the methanol aqueous solution.

[0038] The evaporation module 200 is also equipped with a partition 230, which is located between two adjacent heat exchange plates 220. The partition 230 divides the space between the two adjacent heat exchange plates 220 into two regions: an inflow space and a preheating space. The preheating space is located on the side of the inflow space near the inner wall of the waste heat exchange module 400. By separating the space between the two adjacent heat exchange plates 220 into a preheating space and an inflow space, the partition 230 separates the unpreheated fluid from the preheated fluid, thereby improving evaporation efficiency.

[0039] The evaporation module 200 is divided into inner and outer parts by multiple partitions 230, so that the preheated methanol solution and the newly flowing methanol solution are separated.

[0040] The inflow space and the preheating space at the bottom are connected, so that the newly flowing methanol solution can flow from the bottom of the evaporation module 200 into the preheating space, so that the newly flowing methanol solution mixes with the preheated methanol solution at the bottom of the evaporation module 200, thereby avoiding the direct evaporation of the newly flowing methanol solution.

[0041] The reforming module 100 is positioned above the evaporation module 200. The reforming module 100 has multiple reforming channel groups arranged in a circular array around the purification module 300. Specifically, in this embodiment, the number of reforming channel groups is set to eight. In other embodiments, the number of reforming channel groups can be set to six, seven, nine, etc., according to actual needs. Those skilled in the art can increase or decrease the number of reforming channel groups according to actual requirements.

[0042] The reforming channel group is connected to the evaporation module 200 by a converging channel. The converging channel is used to increase the pressure difference between the gas and the back pressure, providing additional power for the gas flow. According to Le Chatelier's principle, the methanol catalytic reforming reaction will move in the forward direction, thereby increasing the hydrogen production.

[0043] The reforming channel group includes a third reforming pipe 110, a first reforming pipe 120, a catalyst powder collection tank 130, a second reforming pipe 140, and a catalyst pre-positioning tank 150.

[0044] The second reforming pipeline 140, catalyst pre-positioning tank 150, first reforming pipeline 120, catalyst powder collection tank 130, and third reforming pipeline 110 are arranged from bottom to top.

[0045] The second reforming pipe 140 is provided with a second arc-shaped bend section, which is located at the upper end of the second reforming pipe 140 and is connected to the catalyst pre-positioning tank 150. By providing the catalyst pre-positioning tank 150 and the second arc-shaped bend section, the catalyst can be prevented from falling into the evaporation module 200.

[0046] The catalyst pre-positioning tank 150 is connected to the lower end of the first reforming pipeline 120. The catalyst powder collection tank 130 is located above the catalyst pre-positioning tank 150. The first reforming pipeline 120 has a first arc-shaped corner section, which is located at the upper end of the first reforming pipeline 120 and is connected to the catalyst powder collection tank 130. The catalyst powder collection tank 130 is connected to the lower end of the third reforming pipeline 110.

[0047] In this high-purity hydrogen production unit, the entire exterior of the reforming channel group is covered with a metal with high specific heat capacity and high thermal conductivity, and is directly connected to the heat exchange mounting cavity 410 of the waste heat exchange module 400, in order to reduce temperature fluctuations in the reforming pipeline and prevent the occurrence of local hot spots.

[0048] The purification module 300 is equipped with a purification channel, the upper end of which is connected to the third reforming pipeline 110. Reformed gas flows into the purification module 300 through the reforming channel assembly. The purification channel contains several hydrogen permeable membranes 310, specifically copper-palladium membranes. The purification channel is connected to the first reforming pipeline 120. Multiple hydrogen permeable membranes 310 are arranged vertically to form a finned structure. The hydrogen permeable membranes 310 are directly connected to the reforming module 100, enabling heat transfer to the reforming module 100 simultaneously with the purification of the reformed gas, thus achieving energy gradient utilization.

[0049] The high-purity hydrogen production unit also includes a gas pressure detection and control device. This device is located between the purification channel and the reforming channel assembly. It regulates the pressure of the reformed gas, pressurizing it to ensure it meets the power requirements for passing through the hydrogen permeation membrane 310, thus driving the hydrogen through the purification components.

[0050] The evaporation module 200 is equipped with a pressure sensor, which is located at the bottom of the evaporation module 200. In order to reduce pressure fluctuations caused by liquid surface fluctuations, it is necessary to perform a time delay judgment based on pressure changes at different liquid heights. The pressure sensor, in conjunction with the control system and other flow control structures, determines the liquid flow rate at the raw material inlet 210 based on the measured pressure value.

[0051] It also includes a first heating device 500, which is disposed beside the first reforming pipeline 120. The first heating device 500 provides additional thermal conditions for purification and reforming.

[0052] It also includes a second heating device 600, which is disposed in the purification channel and provides thermal conditions for the purification process.

[0053] In other embodiments, the arrangement of the evaporation module and the reforming module is not limited to a vertical arrangement, and the flow path of the high-temperature gas will change accordingly depending on the arrangement of the evaporation module and the reforming module.

[0054] To more clearly and completely illustrate the beneficial effects of this disclosure, computational gas dynamics methods are used to verify these effects. To simplify the numerical calculation process, the evaporation of the methanol-water mixture is considered as the evaporation of pure water, with an evaporation temperature of 80°C. The catalyst section is set as a porous media region, and its viscous resistance and inertial resistance are calculated using the following formulas: Its reciprocal is viscous resistance, inertial resistance. Dp is the catalyst particle size, and ε is the porosity of the catalyst layer.

[0055] The simulation dimensions selected for model calculation are as follows: the total length of the device is 280mm, the diameter is 51mm, the inlet diameter of the methanol aqueous solution is 10mm, the evaporation module 200 has 12 layers of discs 220, the partition 230 divides multiple first holes 221 into inner and outer parts, the number of first holes 221 in the inner layer is 20 and 28 respectively, and the number of first holes 221 in the outer layer is 32 and 40 respectively; the inner diameter of the reforming channel group is 6mm; the total length in the vertical direction is 45mm, and a total of 8 channels are set; the overall length of the heat exchange mounting cavity 410 is 74mm, and the diameter of the heat exchange mounting cavity 410 is 22mm.

[0056] The flow rate of the high-temperature gas inlet 401 is 300 L / h; where 300 L / h = 0.3 m³ / h = 0.3 / 3600 m³ / s. Water flow velocity: Water: Re = ρud / μ = 4148.4, belonging to turbulent flow, Pr = Cpμ / λ = 1.23, Nu = 0.023, Re = 0.8, Pr0.4 = 24.39.

[0057] The model was built using SpaceClaim software, then imported into Meshing software for mesh generation using a hexahedral unstructured mesh. The meshed model was then imported into Fluent for numerical simulation, employing a multiphase flow model, a double-precision solver, and enabling the energy equations. In the multiphase flow model, the three phases were set as air, water, and water vapor, respectively, with the phase transition temperature for water evaporation into water vapor set at 80°C; the Reynolds number was set to 4148.4, and the Ke turbulence model Realizable was used to enhance the wall functions, making the simulation more closely resemble real-world flow.

[0058] The temperature of the heating element in the purification channel is set to 500℃, the temperature of the heating device 500 next to the reforming module 100 is set to 400℃, and the average temperature of industrial waste heat is taken as 300℃.

[0059] Based on numerical simulation results Figure 3 It is clear that the methanol-water solution had completely evaporated before entering the reforming pipeline, according to... Figure 2 It can be seen that all the thermodynamic conditions for methanol reforming to produce hydrogen meet the actual requirements and the temperature is uniform without any localized hot spots.

[0060] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A device for producing high purity hydrogen, characterized by: include: Evaporation module, reforming module, purification module; The purification module passes through the reforming module and the evaporation module in sequence. The evaporation module can transfer heat with the reforming module and the purification module, so that the evaporation module can use the waste heat of the reforming module and the purification module to evaporate the material. The gas in the purification module flows countercurrently to the gas in the evaporation module and the reforming module; the purification module is provided with a purification channel, and the purification channel is provided with several hydrogen selective permeation membranes. The reforming module is equipped with several parallel reforming channel groups. The inlet of the reforming channel group is connected to the evaporation module through a converging channel, and the outlet of the reforming channel group is connected to the purification channel through a pressure controller. The converging channel is used to increase the pressure difference between the gas and the back pressure, provide additional power for gas flow, increase the gas flow rate, and reduce the gas pressure to increase hydrogen production. The reforming channel group includes a second reforming pipe, a catalyst pre-positioning tank, a first reforming pipe, a catalyst powder collection tank, and a third reforming pipe arranged sequentially from bottom to top; the upper end of the purification channel is connected to the third reforming pipe; The catalyst pre-positioning tank is connected to the lower end of the first reforming pipe, and the upper end of the second reforming pipe is provided with a second arc-shaped corner section, the catalyst pre-positioning tank is connected to the second arc-shaped corner section; the catalyst powder collection tank is connected to the lower end of the third reforming pipe, and the upper end of the first reforming pipe is provided with a first arc-shaped corner section, the first arc-shaped corner section is connected to the catalyst powder collection tank. The evaporation module is equipped with multiple heat exchange plates and a pressure sensor; a partition is provided between two adjacent heat exchange plates, which divides the space between the two adjacent heat exchange plates into a preheating space and an inflow space. The partition is used to separate the unpreheated gas from the preheated gas to improve the evaporation efficiency; the pressure sensor is placed at the bottom of the evaporation module.

2. The apparatus for producing high-purity hydrogen according to claim 1, wherein: It also includes a first heating device, which is disposed between the first reforming pipeline and the purification channel; it also includes a waste heat exchange module, which is provided with a high-temperature gas channel and a heat exchange mounting cavity, and the reforming module and the evaporation module are both installed in the heat exchange mounting cavity.

3. The apparatus for producing high purity hydrogen according to claim 2, wherein: The high-temperature gas channel is spirally coiled around the heat exchange mounting cavity; the gas in the high-temperature gas channel flows sequentially past the side of the reforming module and the side of the evaporation module.

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