A multi-tube parallel large-scale photocatalytic hydrogen production device and method based on cyclone strengthening

Abstract

The application provides a multi-tube parallel large-scale photocatalytic hydrogen production device and method based on cyclone strengthening, and relates to the technical field of hydrogen production. The device comprises: a feed distribution unit for uniformly distributing catalyst slurry; a cyclone reaction unit composed of multiple inclined insertion type parallel light-transmitting cyclone reactors, each reactor being provided with a tangential feed port, an overflow port and a underflow port, and the tangential feed port being connected with the distribution unit; a light source introduction unit for introducing light radially into the reactor through an external light source matched with a built-in light guide rod; a gas phase product collection and liquid phase recycling unit for collecting gas phase products through a main pipe and recycling catalyst slurry through a pipeline. While maintaining high activity of the catalyst, the application realizes high integration of reaction-separation and deep coupling of flow field-light field, has excellent engineering amplification characteristics, and provides a feasible path for industrialization of photocatalytic hydrogen production.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, and in particular to a large-scale photocatalytic hydrogen production device and method based on swirl-enhanced multi-tube parallel connection. Background Technology

[0002] Hydrogen energy, as a core component of the future clean energy system, has become a strategic high ground in global energy technology competition due to its large-scale, low-cost, and green production technologies. Solar-powered photocatalytic water splitting (or organic matter reforming) for hydrogen production is considered one of the most promising hydrogen production pathways for sustainable development due to its significant advantages such as direct utilization of solar energy, mild reaction conditions, and zero carbon emissions. However, this technology still faces multiple engineering bottlenecks in its transition from laboratory to industrial application: difficulties in achieving efficient synergy between light energy, flow field, and solid catalyst phases; challenges in rapid in-situ removal of hydrogen products; the difficulty in balancing high activity and efficient continuous recovery of powdered catalysts; and problems such as uneven fluid distribution and significant "scale-up effects" during high-throughput scale-up. Existing technologies have explored these issues extensively, but significant limitations remain at the reactor engineering design level. Traditional batch or tubular reactors (such as CN104226224B and CN117504773A) rely on mechanical stirring or simple flow to enhance mass transfer, but they have limited shear strength, high energy consumption, and hydrogen bubbles tend to remain in the liquid phase for a long time, increasing the probability of reverse reaction and increasing the burden on subsequent separation.

[0003] While immobilized catalyst schemes (such as CN111453696B and CN111874864B) facilitate catalyst recovery, the utilization rate of active sites decreases significantly, and the mass transfer resistance increases significantly. In particular, under high-throughput conditions, local overheating or concentration gradients are prone to occur.

[0004] In recent years, membrane photocatalytic reactors and floating interfacial reaction systems (such as CN111056528B) have achieved rapid product separation to some extent, but due to limitations in effective reaction area and continuous processing capacity, they are difficult to meet the needs of industrial-scale hydrogen production.

[0005] To overcome the bottleneck of single reactor processing capacity, some schemes have attempted to connect multiple reactors in parallel (such as CN119368100A and CN117963840A). However, most of them use simple parallel pipelines and lack scientific fluid distribution theory guidance, resulting in significant differences in feed rate, flow field intensity, and illumination conditions among the parallel units. The overall efficiency is far lower than theoretical expectations, exhibiting a typical "scale-up distortion" phenomenon.

[0006] In terms of enhancing the coupling between the light field and the flow field, existing methods mostly employ central optical fiber or external focusing light introduction (such as CN101973519B). However, the uniformity of light energy in three-dimensional space is still insufficient. Especially under conditions of high solid content and multiphase turbulence, obvious "light dead zone" and "overexposure zone" are easily formed, which limits the further improvement of light quantum efficiency.

[0007] Based on the above analysis, there is an urgent need in this field for a novel, multi-tube parallel configuration cyclone-enhanced photocatalytic hydrogen production reactor. This reactor should maintain the high activity of the powdered catalyst while achieving a high degree of integration of reaction and separation, deep coupling of flow field and light field, and good engineering scale-up characteristics, thereby providing a feasible path for the industrialization of photocatalytic hydrogen production technology. Summary of the Invention

[0008] In view of this, the purpose of this invention is to overcome the shortcomings of the prior art and provide a large-scale photocatalytic hydrogen production device and method based on swirling enhanced multi-tube parallel connection. While maintaining the high activity of powder catalyst, it achieves high integration of reaction and separation, deep coupling of flow field and light field, and has good engineering scale-up characteristics, thereby providing a feasible path for the industrialization of photocatalytic hydrogen production technology.

[0009] This invention provides the following technical solution: In a first aspect, embodiments of this application provide a large-scale photocatalytic hydrogen production device based on swirling-enhanced multi-tube parallel connection, the device comprising: The feed distribution unit is used to evenly distribute the catalyst slurry; The swirl reaction unit includes multiple obliquely inserted parallel swirl reactors. The swirl reactors are made of a light-transmitting material and are respectively provided with a tangential feed inlet, an overflow outlet and an underflow outlet. The tangential feed inlet is connected to the feed distribution unit. The light source introduction unit includes an external light source and a built-in light guide rod. The built-in light guide rod is coaxially arranged inside the swirling reaction unit and is used to radially introduce the light from the external light source into the swirling reactor. The gas phase product collection and liquid phase recycling unit includes a gas phase product outlet manifold connected to the overflow port and a catalyst slurry circulation pipeline connected to the underflow port.

[0010] In some embodiments of the first aspect, the multi-tube parallel large-scale photocatalytic hydrogen production device based on swirl enhancement has an inner cavity, and a first cylindrical body and a second cylindrical body are sequentially sleeved from the outside to the inside. The second cylindrical body is light-transmitting and divides the inner cavity from the inside to the outside into a slurry collection cavity, a feed cavity and an outer overflow cavity. The tangential feed inlets of the plurality of cyclone reactors are connected to the feed chamber, the overflow outlets are connected to the outer overflow chamber, and the underflow outlets are connected to the slurry collection chamber; The gas phase product outlet manifold is connected to the outer overflow cavity, and one end of the catalyst slurry circulation pipeline is connected to the slurry collection cavity, while the other end is connected to the feed distribution unit.

[0011] In some embodiments of the first aspect, the surface of the built-in light guide is provided with a light scattering microstructure, the light scattering microstructure being selected from one or more combinations of microlens arrays, frosted surfaces, grating structures, and coatings doped with scattering particles.

[0012] In some embodiments of the first aspect, the axis of the cyclone reactor has an acute angle β between itself and the horizontal line, the angle β ranging from α to 60°, where α is the angle of repose of the catalyst particles.

[0013] In some embodiments of the first aspect, the longitudinal section of the slurry collecting cavity is spindle-shaped and includes an upper columnar collecting section, a middle diameter expanding section and a lower discharge section connected in sequence.

[0014] In some embodiments of the first aspect, the external light source is sunlight or an electronic light source.

[0015] Secondly, this application also provides a method for large-scale photocatalytic hydrogen production using a multi-tube parallel system with cyclone enhancement, employing the apparatus described in any of the above embodiments, comprising the following steps: S100: Turn on the external light source, and the light is introduced through the built-in light guide and radially and evenly distributed to each cyclone reactor; S200: The slurry containing photocatalyst and reaction liquid is evenly distributed through the feed distribution unit and tangentially injected into the cyclone reactor. Under the synergistic effect of the light field and the cyclone field, the photocatalytic hydrogen production reaction is carried out. The generated hydrogen gas is enriched towards the center under the action of centrifugal force and discharged through the overflow port to achieve in-situ separation. S300: Hydrogen is collected through the gas phase product outlet manifold. The separated catalyst slurry is partially recycled back to the feed distribution unit through the catalyst slurry circulation pipeline for reuse, and the remaining part is discharged and fresh catalyst is added.

[0016] In some embodiments of the first aspect, in S300, the catalyst slurry is recycled at a rate of 10% to 80% of the total feed flow.

[0017] In some embodiments of the first aspect, the reaction solution is a mixture of ultrapure water and a sacrificial agent or industrial wastewater containing oxidizable organic matter.

[0018] The embodiments of the present invention have the following advantages: The large-scale photocatalytic hydrogen production device based on swirling enhancement and multi-tube parallel connection provided by this invention has a feed distribution unit located in the middle layer of the device. Its core is an annular feed chamber, used to uniformly distribute fresh catalyst slurry (containing photocatalyst powder and reaction liquid) to multiple inclined swirling reactors, ensuring balanced feed flow in each reaction channel and avoiding the scale-up effect of traditional parallel connections. The swirling reaction unit, located in the middle of the device, consists of multiple inclined parallel swirling reactors. Each swirling reactor has a tangential feed inlet, overflow outlet, and underflow outlet, with its axis forming an acute angle with the horizontal line. This inclined layout not only improves the space utilization of the device but also promotes the full development of the swirling field within the channels and the rapid radial migration of hydrogen bubbles. The light source introduction unit includes an external light source (such as a solar concentrator or LED array) and a built-in light guide rod. The light guide rod is coaxially positioned at the center of the inner slurry collection chamber, and its surface has light scattering microstructures to efficiently introduce and radially and uniformly disperse light energy into the inclined reaction channels, achieving three-dimensional light field optimization. The gas phase product collection and liquid phase recycling unit is integrated into the outer layer and bottom of the device. It includes a hydrogen collection pipe connected to the overflow chamber and a circulation pipeline connecting the slurry collection chamber and the feed distribution unit. It is used to collect hydrogen in real time and return the catalyst-rich slurry to achieve continuous recycling.

[0019] Compared to existing technologies, this application boasts high space utilization and integration. The obliquely inserted multi-tube parallel design significantly improves the device's volumetric efficiency, reducing footprint and height compared to traditional vertical or horizontal parallel connections, making it suitable for compact industrial environments. The obliquely inserted channels promote strong synergy between the swirling flow field and radial light scattering, enhancing mass transfer rates while suppressing catalyst sedimentation and ensuring exposure of highly active sites. The uniform distribution based on the obliquely inserted layout avoids the uneven flow field of traditional parallel connections, allowing for flexible scaling to industrial-scale production without sacrificing efficiency. In-situ hydrogen separation efficiency is high, and catalyst reuse rate is high. If organic wastewater is used as the reaction liquid, pollutant degradation and hydrogen production can be achieved simultaneously, providing dual environmental benefits.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] 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.

[0022] Figure 1This diagram shows a schematic view of a large-scale photocatalytic hydrogen production device based on swirl enhancement and multi-tube parallel connection, provided by an embodiment of the present invention. Figure 2 This diagram shows a schematic structural view of a cyclone separator provided by an embodiment of the present invention. Figure 3 The figure shows a graph illustrating the relationship between the installation angle β of a cyclone separator and the maximum allowable concentration of inlet particles Ci, according to an embodiment of the present invention. Figure 4 The diagram illustrates the principle flow of a large-scale photocatalytic hydrogen production method based on swirling-enhanced multi-tube parallel connection provided by an embodiment of the present invention.

[0023] Explanation of key component symbols: 1-Feed distribution unit; 2-Swirl reaction unit; 21-Tangential feed inlet; 22-Overflow port; 23-Underflow port; 3-Light source introduction unit; 41-Gas phase product outlet manifold; 42-Catalyst slurry circulation pipeline. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] like Figure 1 and Figure 2 As shown, in order to solve the above-mentioned technical problems, this application provides a large-scale photocatalytic hydrogen production device based on swirling-enhanced multi-tube parallel connection, the device comprising: Feed distribution unit 1 is used to uniformly distribute the catalyst slurry; The swirl reaction unit 2 includes multiple obliquely inserted parallel swirl reactors. The swirl reactors are made of a light-transmitting material and are respectively provided with a tangential feed inlet 21, an overflow outlet 22 and an underflow outlet 23. The tangential feed inlet 21 is connected to the feed distribution unit 1. The light source introduction unit 3 includes an external light source and a built-in light guide rod. The built-in light guide rod is coaxially arranged inside the swirling reaction unit 2 and is used to radially introduce the light from the external light source into the swirling reactor. The gas phase product collection and liquid phase recycling unit includes a gas phase product outlet manifold 41 connected to the overflow port 22 and a catalyst slurry circulation pipeline 42 connected to the underflow port 23.

[0030] In these embodiments, this application provides a large-scale photocatalytic hydrogen production device based on swirl-enhanced multi-tube parallel connection, which includes the following components: The feed distribution unit 1 includes a central feed main pipe and a multi-stage diversion distributor connected thereto. This distributor employs a biomimetic tree-like branching structure or an equal-pressure-drop annular distribution chamber design to ensure that the catalyst slurry flowing into each parallel branch has the same flow rate and pressure. For example, there are 12 parallel branches, each corresponding to a cyclone reactor.

[0031] The swirl reaction unit 2 includes multiple obliquely inserted parallel swirl reactors. Each reactor is installed at a 15° angle along the circumferential direction on the reactor support frame, forming a radial layout, which is beneficial for uniform illumination and compact space.

[0032] Each cyclone reactor is made of high-transmittance quartz glass and is cylindrical. It has a tangential feed inlet 21 on its side wall, which is sealed to the corresponding branch of the feed distribution unit 1 via a quick-connect flange; an overflow port 22 is provided at the top for discharging the light phase (gas phase product mainly composed of hydrogen); and an underflow port 23 is provided at the bottom for discharging the concentrated phase.

[0033] When the catalyst slurry enters the cyclone reactor through the tangential feed inlet 21, a strong swirling field is formed under the action of centrifugal force: the heavy phase (catalyst particles) is thrown against the reactor wall and flows upward along a spiral path, exiting from the underflow outlet 23; the light phase (gas-phase products mainly composed of hydrogen) converges towards the central low-pressure zone, flows downward, and overflows from the overflow outlet 22. This swirling structure enables in-situ enrichment of the catalyst and rapid removal of hydrogen during the reaction process, significantly reducing bubble entrainment.

[0034] The light source introduction unit 3 includes an external high-power LED array light source and a built-in light guide rod. The light guide rod is arranged coaxially along the geometric central axis of the entire swirling reaction unit 2, penetrating the internal cavities of all swirling reactors.

[0035] Ultraviolet-visible light emitted from an external light source is focused by a condenser lens assembly and coupled into a light guide rod. It then undergoes total internal reflection and propagates axially. A microprism structure on the sidewall of the light guide rod ensures uniform radial light emission, allowing the light to radiate from the center of the reactor outwards and penetrate the swirling liquid film. Because the thin liquid film formed by the swirling flow adheres closely to the light-transmitting wall of the swirling reactor and is in a high-speed rotating state, the light shielding effect present in traditional static systems is effectively avoided, significantly improving photon utilization.

[0036] The overflow port 22 is connected to the gas phase product outlet manifold 41 through a pipeline. This manifold is connected to the gas-liquid separator to achieve the initial separation of hydrogen and liquid. The hydrogen is dried and stored, while the liquid is returned to the slurry preparation system.

[0037] The underflow port 23 is connected to the slurry storage tank through the catalyst slurry circulation pipeline 42, and then pumped back into the feed distribution unit 1 to form a closed loop.

[0038] During startup, the catalyst slurry is evenly distributed to each cyclone reactor by the feed distribution unit 1; at the same time, the external light source is turned on, and the light is radially introduced into the center of each reactor through the light guide rod; after the slurry enters tangentially, it forms a cyclone, and the photocatalytic reaction takes place in a high-speed rotating thin liquid film; the generated hydrogen gas quickly gathers towards the center and is discharged with the overflow, while the catalyst is enriched in the underflow for recycling.

[0039] In some embodiments, the multi-tube parallel large-scale photocatalytic hydrogen production device based on swirl enhancement has an inner cavity, and a first cylindrical body and a second cylindrical body are sequentially sleeved from the outside to the inside. The second cylindrical body is light-transmitting and divides the inner cavity from the inside to the outside into a slurry collection cavity, a feed cavity and an outer overflow cavity. The tangential feed inlet 21 of the plurality of cyclone reactors is connected to the feed chamber, the overflow port 22 is connected to the outer overflow chamber, and the underflow port 23 is connected to the slurry collection chamber; The gas phase product outlet manifold 41 is connected to the outer overflow cavity, and one end of the catalyst slurry circulation pipeline 42 is connected to the slurry collection cavity, while the other end is connected to the feed distribution unit 1.

[0040] In these embodiments, a highly integrated photocatalytic hydrogen production device is provided, the core of which is the use of a three-layer concentric cylindrical structure, which integrates the traditionally dispersed functions of fluid distribution, reaction and product separation into a single compact cavity, significantly improving the system's sealing performance, flow field uniformity and space utilization.

[0041] The device has a cylindrical main shell, inside which a first cylindrical body and a second cylindrical body are sequentially nested from the outside in. Specifically: the first cylindrical body is an opaque metal cylinder (such as 316L stainless steel) and constitutes the outermost structure of the device; the second cylindrical body is made of high-transmittance quartz glass and is coaxially nested inside the first cylindrical body. Three independent annular / cylindrical chambers are formed between the two cylinders and inside the second cylindrical cylinder: Slurry collection chamber: located in the central area inside the second cylindrical body; Feed chamber: located in the second cylindrical body; Outer overflow cavity: located in the first cylindrical body.

[0042] In this embodiment, a plurality of inclined swirl reactors are provided, which are evenly distributed around the periphery of the second cylindrical body along the circumferential direction and penetrate the wall between the first cylindrical body and the second cylindrical body at a preset angle.

[0043] The interfaces of each cyclone reactor are connected to different chambers: After passing through the first cylindrical body, the tangential feed inlet 21 connects to the feed chamber—that is, the catalyst slurry enters the cyclone reactor from the feed chamber through the tangential inlet. The overflow port 22 extends upward and connects to the outer overflow chamber, where the light phase (gas-phase products mainly composed of hydrogen) overflows and directly flows into the outer overflow chamber. The underflow port 23 extends downward and connects to the slurry collection chamber, where the concentrated phase enriched with catalyst settles into the central slurry collection chamber.

[0044] This design achieves embedded fluid distribution and collection without external piping, significantly reducing dead volume and pressure loss, while avoiding the uneven flow distribution problem common in multi-pipe parallel systems.

[0045] The gas phase product outlet manifold 41 is led out from the top of the device and connected to the outer overflow chamber, which is used to uniformly export the hydrogen-containing overflow liquid generated by all the cyclone reactors to the gas-liquid separation unit. One end of the catalyst slurry circulation pipeline 42 is connected to the bottom outlet of the slurry collection chamber, and the other end returns to the feed distribution unit 1 after passing through the circulation pump, thus completing the closed-loop circulation of the catalyst.

[0046] An internal light guide rod runs along the central axis of the entire device through the slurry collection chamber. The light emitted from it penetrates radially through the second cylindrical body and illuminates the inner walls of multiple swirling reactors surrounding it. Because the swirling reactors are in close contact with the light-transmitting cylinder and form a high-speed rotating thin liquid film inside, the light energy utilization rate is significantly improved.

[0047] In some embodiments, the surface of the built-in light guide rod is provided with a light scattering microstructure, which is selected from one or more combinations of microlens arrays, frosted surfaces, grating structures, and coatings doped with scattering particles.

[0048] In these embodiments, the outer surface of the built-in light guide rod is provided with light scattering microstructures to break the total internal reflection condition and enable the guided light to be emitted radially efficiently and uniformly into multiple surrounding swirling reactors.

[0049] In this embodiment, the light scattering microstructure takes any of the following forms or a combination thereof: Microlens array: Periodic protruding microlenses are formed on the surface of the light guide rod by hot embossing or laser direct writing process, so that the light is refracted and emitted radially in a divergent manner; Frosted surface: The outer wall of the light guide is sandblasted to achieve wide-angle light distribution through random scattering; Grating structure: Subwavelength periodic gratings are etched on the surface of the light guide rod, and the direction angle of the emitted light is controlled by diffraction; Coating with doped scattering particles: A transparent resin coating with a thickness of 10-50 μm is coated on the outer surface of the light guide rod, in which TiO2 or SiO2 nanoparticles are uniformly dispersed to enhance radial light output by Mie scattering.

[0050] When ultraviolet and visible light emitted from an external light source couples into the light guide rod, during transmission, the light scattering microstructure continuously converts part of the guided light into a radiation mode, achieving uniform illumination that is continuous along the axial direction and divergent in the radial direction. Because the swirling reactor is in close contact with the light-transmitting second cylindrical body and forms a high-speed rotating thin liquid film inside, light can efficiently penetrate the reaction liquid layer, exciting the suspended catalyst particles and significantly improving the quantum efficiency.

[0051] In some embodiments, the axis of the cyclone reactor has an acute angle β between it and the horizontal line, the angle β ranging from α to 60°, where α is the angle of repose of the catalyst particles.

[0052] In these embodiments, the plurality of swirl reactors are not installed vertically or parallel to the central axis, but are arranged at an angle, such that their own axis forms the aforementioned angle β with the horizontal line.

[0053] All the swirl reactors are radially distributed around the outer periphery of the second cylindrical shell. The central axis of each reactor extends obliquely from the outer edge of the top of the device toward the center of the bottom, eventually pointing toward or near the axis of the central light guide rod, forming an angle β with the horizontal line.

[0054] The specific values ​​and effects of the included angle β: When β = 10°: the cyclone reactor is close to horizontal, the axial component of gravity is small, which is more conducive to reducing flow resistance and the fluid pressure drop is small, making it suitable for low viscosity slurries or low energy consumption scenarios. When β = 30°: it exhibits good overall performance in terms of centrifugal force, optical path length, and spatial arrangement density. At this point, the distance between the reactor inner wall and the surface of the light guide gradually decreases along the axial direction, making the incident angle of light closer to the normal and improving light transmission efficiency; at the same time, the inclined structure enhances secondary flow and promotes bubble detachment. When β = 60°: the swirl intensity is significantly enhanced, the catalyst settling path is shortened, which is beneficial for the continuous operation of the high solids content system, but requires higher pumping power and the top installation space is limited.

[0055] This inclined layout allows multiple swirling reactors to be arranged in a high-density ring within a limited radial space, avoiding mutual obstruction, while ensuring that each reactor can effectively receive radial outgoing light from the central light guide.

[0056] Because the cyclone reactor is installed at an angle β, the swirling liquid film formed inside it not only rotates circumferentially but also flows spirally in the axial direction, further enhancing mass transfer and bubble stripping. Simultaneously, the gap between the reactor inner wall and the light guide gradually changes along the flow direction, creating a dynamic optical path modulation effect: moderate light intensity in the upstream region facilitates reaction initiation, while increased light intensity in the downstream region due to the thinner liquid film compensates for catalyst activity decay, achieving a uniform reaction rate along the flow path. This oblique installation not only improves the space utilization of the device but also promotes the full development of the swirling field within the channel and the rapid radial migration of hydrogen bubbles.

[0057] In some embodiments, the cyclone reactor is arranged in an inverted configuration, and the included angle β is greater than the angle of repose of the catalyst particles to be treated.

[0058] In this embodiment, the cyclone reactor is installed in an inverted configuration. An inverted configuration means that the overflow port 22 of the cyclone reactor is located in the lower region of the device, while the underflow port 23 faces the slurry collection chamber at the upper center.

[0059] More importantly, the acute angle β between the axis of the cyclone reactor and the horizontal line is designed to be greater than the angle of repose of the catalyst particles to be treated. This ensures that the dense-phase catalyst slurry forms static accumulation or blockage on the inclined tube wall.

[0060] like Figure 3 As shown, the horizontal axis represents the installation angle β, and the vertical axis represents the maximum allowable concentration of inlet catalyst slurry particles Ci. The figure contains two curves, representing the upright and inverted loading modes, respectively. The curves clearly show that, at the same installation angle, the allowable inlet concentration in the inverted loading mode is much higher than that in the upright loading mode; and as the installation angle increases, the allowable inlet concentration in the inverted loading mode shows a significant upward trend.

[0061] In some embodiments, the longitudinal section of the slurry collecting cavity is spindle-shaped and includes an upper columnar collecting section, a middle diameter-expanding section, and a lower discharge section connected in sequence.

[0062] In these embodiments, the longitudinal section of the slurry collection cavity, from top to bottom along the axial direction, includes: Upper columnar collecting section: used to collect the dense phase slurry discharged from the underflow outlets of each swirl reactor and maintain a relatively stable flow field. When dense phase slurry from multiple swirl reactors converges, this structure can suppress eddy current disturbances caused by sudden changes in flow velocity, while maintaining a moderate back pressure at the underflow outlet 23 of the swirl reactor to prevent external gas backflow or liquid phase short circuit; The central expansion section, the region with the largest diameter, serves as a buffer for the slurry and removes air bubbles. The expansion causes a sharp drop in flow velocity, giving the entrained trace hydrogen bubbles sufficient time to rise and escape, preventing them from entering the circulating pump and causing cavitation or flow fluctuations. Lower discharge section: Connects to catalyst slurry circulation pipeline 42. Its structural design (can be conical or cylindrical) is designed to efficiently divert and circulate the slurry, ensuring that the dense phase slurry flows out stably under the combined action of gravity and pump suction, without any dead spots of sedimentation.

[0063] In some embodiments, the external light source is sunlight or an electronic light source.

[0064] like Figure 4 As shown, in some embodiments, this application also provides a method for large-scale photocatalytic hydrogen production using a multi-tube parallel system with cyclone enhancement, employing the apparatus described in any one of the above embodiments, comprising the following steps: S100: Turn on the external light source, and the light is introduced through the built-in light guide and radially and evenly distributed to each swirl reactor.

[0065] In these embodiments, an external high-power LED array light source is activated to emit ultraviolet light with a dominant wavelength of 365 nm. The light is coupled into the built-in light guide rod through a focusing lens group. Due to the light scattering microstructures (such as microlens arrays or coatings doped with scattering particles) on the surface of the light guide rod, the light energy is continuously converted into radial radiation light during axial transmission, uniformly illuminating the inner walls of the multiple swirling reactors arranged around it.

[0066] S200: The slurry containing the photocatalyst and reaction liquid is uniformly distributed through the feed distribution unit 1 and tangentially injected into the cyclone reactor. Under the synergistic effect of the light field and the cyclone field, the photocatalytic hydrogen production reaction is carried out. The generated hydrogen gas is enriched towards the center under the action of centrifugal force and discharged through the overflow port 22 to achieve in-situ separation.

[0067] In these embodiments, a pre-prepared catalyst slurry is fed into the feed distribution unit 1 via a feed pump. After being evenly distributed by a multi-stage distributor, the slurry is tangentially injected into the tangential feed inlet 21 of each cyclone reactor.

[0068] Inside the cyclone reactor, the slurry forms a high-speed rotating thin liquid film under centrifugal force, adhering closely to the light-transmitting wall. Under the synergistic effect of this cyclone field and the light field, the catalyst is excited to generate electron-hole pairs, driving water splitting and methanol oxidation, continuously producing hydrogen.

[0069] The generated hydrogen bubbles, due to their low density, rapidly migrate and accumulate in the central low-pressure zone within the swirling flow field. They then move with the light phase liquid and are discharged from the overflow port 22. Meanwhile, the catalyst particles are thrown against the vessel wall by centrifugal force and enter the slurry collection chamber from the bottom outlet 23 under the action of the swirling centrifugal force.

[0070] S300: Hydrogen is collected through the gas phase product outlet manifold 41. The separated catalyst slurry is partially recycled back to the feed distribution unit 1 through the catalyst slurry circulation pipeline 42 for recycling, and the remaining part is discharged and fresh catalyst is added.

[0071] In these embodiments, the gaseous product mainly composed of hydrogen or a hydrogen-rich fluid containing a small amount of liquid entrainment is discharged from the overflow port 22 of each cyclone reactor. In a preferred embodiment, the hydrogen-rich fluid can be collected as a hydrogen product after being discharged through the outer overflow chamber / gas-phase product outlet manifold. If necessary, the entrained droplets can be further removed by a gas-liquid separator.

[0072] The dense-phase slurry entering the slurry collection chamber undergoes bubble removal and flow stabilization within the spindle-shaped structure before being led out through the bottom catalyst slurry circulation pipeline 42. Of this, 10% to 80% of the slurry is recycled to the feed distribution unit 1, mixed with fresh slurry, and then reinjected into the reactor, achieving efficient catalyst recycling. 5% to 15% of the slurry is discharged to compensate for trace amounts of deactivation or loss during operation, and simultaneously replenishes an equal amount of fresh catalyst to maintain stable system activity.

[0073] In some embodiments, in S300, the catalyst slurry is recycled at a rate of 10% to 80% of the total feed flow to maintain catalyst activity.

[0074] In some embodiments, the reaction solution is a mixture of ultrapure water and a sacrificial agent or industrial wastewater containing oxidizable organic matter.

[0075] In some embodiments, the number of parallel swirling reactors in the swirling reaction unit 2 can be flexibly configured in the range of 1 to 300, and the fluid distribution and light field coverage can be optimized by adjusting the oblique insertion angle.

[0076] For example, in a large-scale photocatalytic hydrogen production pilot plant in a hydrogen energy industry demonstration park, the method of the present invention is used to treat methanol-containing organic wastewater discharged from the surrounding chemical industrial park using the aforementioned multi-tube parallel large-scale photocatalytic hydrogen production device based on cyclone enhancement. This achieves both industrial wastewater pretreatment and large-scale hydrogen energy recovery. The specific operation process and effects are described below: 1. Wastewater properties and related parameters The properties and parameters of the methanol-containing organic wastewater discharged from the chemical industrial park before the reaction are shown in Table 1 below.

[0077]

[0078] 2. Large-scale photocatalytic hydrogen production experimental device with multiple tubes in parallel The experimental apparatus adopts the integrated tank structure described in this invention, mainly including a feeding and distribution unit 1, a swirling reaction unit 2, a light source introduction unit 3, and a gas phase product collection and liquid phase recycling unit.

[0079] The main body of the device is 2.7 m high and the tank diameter is 0.8 m. The cyclone reaction unit 2 consists of 240 obliquely inserted parallel cyclone reactors. The nominal diameter of the cyclone core tube is 20 mm, the effective reaction length is 300 mm, and the material is high-transmittance quartz glass. The installation angle between the axis of each cyclone core tube and the horizontal plane is 30°, and they are arranged in an inverted configuration.

[0080] The feed distribution unit 1 is an annular feed chamber connected to the tangential feed inlets 21 of all cyclone reactors, used to uniformly distribute the catalyst slurry to 260 cyclone core tubes. The light source introduction unit 3 includes an external LED light source (total power 150 kW, spectral range 350-700 nm) and a built-in light guide rod. The light guide rod is coaxially arranged with the slurry collection chamber, and its top is connected to the external light source, allowing the introduced light energy to be uniformly emitted radially to each cyclone reactor. The gas phase product collection and liquid phase recycling unit includes a hydrogen collection manifold connected to the overflow chamber and a catalyst slurry circulation pipeline 42 connecting the slurry collection chamber and the feed distribution unit 1. The overall processing capacity of the unit is designed to be 80 m³ / h.

[0081] 3. Implementation Process The method of this invention is implemented as follows: S100: Introduction and uniform distribution of external light source: When the external LED light source is turned on, light energy is introduced from the top of the light guide rod through the light guide element. The light energy is efficiently concentrated and radially uniformly distributed to the swirling reaction unit 2 through the light scattering structure on the surface of the light guide rod, ensuring that there are no dead zones in the illumination within the 260 oblique insertion channels.

[0082] S200: Photocatalytic reaction and simultaneous hydrogen separation in a swirling field: Methanol-containing organic wastewater, sacrificial agent (methanol in the wastewater), and photocatalyst (8 wt% solids content) are prepared into a catalyst slurry, which is uniformly distributed and tangentially injected into 260 parallel swirling reactors via feed distribution unit 1. The feed flow rate of each reactor is controlled at 0.308 m³ / h, with a total processing capacity of 80 m³ / h, equivalent to a feed linear velocity of 5.7 m / s. The material forms a strong swirling field within the reactor. Under the synergistic effect of the uniform light field provided in step S100 and the strong swirling field formed by tangential injection, a highly efficient photocatalytic hydrogen production reaction occurs in the swirling reactor. Simultaneously, hydrogen bubbles are enriched towards the center under the centrifugal force of the swirling flow and discharged from the overflow port 22, achieving simultaneous in-situ separation. Due to the 30° slanted insertion angle inverted configuration, the deposition and blockage of catalyst particles at the bottom outlet 23 are effectively prevented.

[0083] S300: Product Collection and Catalyst Slurry Recycling: Hydrogen is collected through the overflow chamber outlet, and the remaining catalyst slurry after separation is partially returned to the feed distribution unit 1 through the circulation pipeline. The recycling ratio is controlled at 65%, and the remaining 35% is discharged from the system as slurry. The system operates continuously and stably for 120 hours.

[0084] 4. Implementation Results After the system stabilized, the test results are as follows: The relative deviation of light intensity at the inlet of each swirl reactor is less than 6%, indicating that the built-in light guide rod combined with the light scattering microstructure achieves uniform illumination under large-scale parallel conditions.

[0085] During 120 hours of continuous operation, no blockages were observed at any of the 260 underflow ports 23 of the cyclone reactors, and the pressure drop of the unit remained stable. Compared with the vertical installation mode, the particle concentration near the underflow port 23 was reduced by approximately 75%, verifying the significant advantage of the inverted installation mode in preventing particle deposition.

[0086] The average hydrogen yield was 1220 mmol / h, which is about 3.0 times higher than that of a conventional reactor (about 410 mmol / h) under the same conditions; the purity of the collected hydrogen was higher than 99.5%.

[0087] The properties and parameters of the treated wastewater are shown in Table 2 below. The COD removal rate reached 87.3%, and the methanol removal rate reached 93.6%.

[0088]

[0089] The gas-liquid separation efficiency of the cyclone reaction unit 2 is stable at over 96.5%, and the catalyst recovery rate is greater than 92%, achieving efficient catalyst recovery through the circulation pipeline.

[0090] Compared to traditional vertical parallel connection, the oblique insertion multi-tube parallel design reduces the device height by about 25%, achieving compact integration.

[0091] After 120 hours of continuous operation, the hydrogen yield fluctuated within ±4%, and the operating conditions of each reactor were consistent, with no obvious scale-up effect observed.

[0092] The above results show that the device and method described in this invention, at an engineering scale of 80 m³ / h, achieves efficient integration of large-scale photocatalytic hydrogen production reaction and in-situ separation through a slanted multi-tube parallel structure and cyclone enhancement technology. It effectively purifies methanol-containing organic wastewater while producing hydrogen on a large scale, and has good prospects for industrial application.

[0093] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0094] 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.

[0095] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A large-scale photocatalytic hydrogen production device based on swirl-enhanced multi-tube parallel connection, characterized in that, The large-scale photocatalytic hydrogen production device based on swirl-enhanced multi-tube parallel configuration includes: The feed distribution unit is used to evenly distribute the catalyst slurry; The swirl reaction unit includes multiple obliquely inserted parallel swirl reactors. The swirl reactors are made of a light-transmitting material and are respectively provided with a tangential feed inlet, an overflow outlet and an underflow outlet. The tangential feed inlet is connected to the feed distribution unit. The light source introduction unit includes an external light source and a built-in light guide rod. The built-in light guide rod is coaxially arranged inside the swirling reaction unit and is used to radially introduce the light from the external light source into the swirling reactor. The gas phase product collection and liquid phase recycling unit includes a gas phase product outlet main pipe connected to the overflow port and a catalyst slurry circulation pipeline connected to the underflow port. The cyclone reactor has an acute angle β between its axis and the horizontal line, and the angle β ranges from α to 60°, where α is the angle of repose of the catalyst particles. The cyclone reactor is arranged in an inverted configuration.

2. The large-scale photocatalytic hydrogen production device based on swirl-enhanced multi-tube parallel connection according to claim 1, characterized in that, The large-scale photocatalytic hydrogen production device based on swirl enhancement has an inner cavity, and a first cylindrical body and a second cylindrical body are sequentially arranged from the outside to the inside. The second cylindrical body is light-transmitting and divides the inner cavity from the inside to the outside into a slurry collection cavity, a feed cavity and an outer overflow cavity. The tangential feed inlets of the plurality of cyclone reactors are connected to the feed chamber, the overflow outlets are connected to the outer overflow chamber, and the underflow outlets are connected to the slurry collection chamber; The gas phase product outlet manifold is connected to the outer overflow cavity, and one end of the catalyst slurry circulation pipeline is connected to the slurry collection cavity, while the other end is connected to the feed distribution unit.

3. The large-scale photocatalytic hydrogen production device based on swirl enhancement and multi-tube parallel connection according to claim 2, characterized in that, The surface of the built-in light guide rod is provided with a light scattering microstructure, which is selected from one or more combinations of microlens arrays, frosted surfaces, grating structures and coatings doped with scattering particles.

4. The large-scale photocatalytic hydrogen production device based on swirl-enhanced multi-tube parallel connection according to claim 2, characterized in that, The longitudinal section of the slurry collecting cavity is spindle-shaped and includes an upper columnar collecting section, a middle diameter expanding section and a lower discharge section connected in sequence.

5. The large-scale photocatalytic hydrogen production device based on swirl enhancement and multi-tube parallel connection according to claim 1, characterized in that, The external light source is sunlight or an electronic light source.

6. A method for large-scale photocatalytic hydrogen production using multiple parallel tubes based on swirl-enhanced technology, applied to the apparatus as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S100: Turn on the external light source, and the light is introduced through the built-in light guide and radially and evenly distributed to each cyclone reactor; S200: The slurry containing photocatalyst and reaction liquid is evenly distributed through the feed distribution unit and tangentially injected into the cyclone reactor. Under the synergistic effect of the light field and the cyclone field, the photocatalytic hydrogen production reaction is carried out. The generated hydrogen gas is enriched towards the center under the action of centrifugal force and discharged through the overflow port to achieve in-situ separation. S300: Hydrogen is collected through the gas phase product outlet manifold. The separated catalyst slurry is partially recycled back to the feed distribution unit through the catalyst slurry circulation pipeline for reuse, and the remaining part is discharged and fresh catalyst is added.

7. The method for large-scale photocatalytic hydrogen production using multiple parallel tubes based on swirl enhancement according to claim 6, characterized in that, In S300, the recycling rate of the catalyst slurry accounts for 10% to 80% of the total feed flow.

8. The method for large-scale photocatalytic hydrogen production based on swirling-enhanced multi-tube parallel connection according to claim 6, characterized in that, The reaction solution is a mixture of ultrapure water and a sacrificial agent or industrial wastewater containing oxidizable organic matter.

9. The method for large-scale photocatalytic hydrogen production using multiple parallel tubes based on swirl enhancement according to claim 8, characterized in that, The sacrificial agent is selected from one or more of methanol, ethanol, and ascorbic acid.

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