A photocatalytic device and method for hydrogen production and hydrogen extraction in a two-stage series connection

Abstract

The application provides a cyclone reinforced hydrogen production and hydrogen extraction two-stage series light catalytic device and method, and relates to the technical field of hydrogen production. The device comprises a light cyclone hydrogen production device and a cyclone hydrogen extraction device which are connected in series and physically separated. The hydrogen production device is provided with parallel cyclone reactors, a feed distribution unit, and a light source introduction unit composed of an external light source and an embedded light guide rod. The hydrogen extraction device is provided with parallel cyclone separators, the top overflow port of which is connected to a gas phase collection unit, and the bottom underflow port is connected back to the feed distribution unit through a liquid phase circulation recycling unit. The application decouples the reaction and separation, and synergistically enhances the hydrogen production and extraction efficiency through a strong cyclone field, a uniform light field and a modular parallel structure, thereby improving the processing capacity and flexibility.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, and in particular to a photocatalytic device and method for two-stage tandem hydrogen production and extraction using cyclone-enhanced hydrogen production. Background Technology

[0002] Hydrogen energy is a highly efficient and clean secondary energy source. Among numerous hydrogen production technologies, photocatalytic water splitting technology can directly convert water into hydrogen using sunlight. The reaction process is mild and environmentally friendly, making it considered one of the most promising green hydrogen production technologies. This technology directly converts solar energy into chemical energy for storage, using water as the feedstock, and theoretically produces no carbon emissions, thus possessing immense development potential. The photocatalytic reactor, as the core equipment for realizing the conversion of light energy into chemical energy, directly determines the hydrogen production efficiency and its potential for large-scale application. In recent years, researchers have conducted extensive innovative work on photocatalytic reactors, but there is still room for improvement in areas such as photo-fluid synergistic enhancement, the uniformity of multi-unit parallel operation, and the decoupling control of reaction and separation.

[0003] In terms of light-flow synergistic enhancement, existing technologies such as CN206901818U use a swirling flow generator to enhance fluid turbulence and improve mass transfer, CN119368100A improves light energy utilization by using a bottom light source in conjunction with a reflective inner wall, and CN219596606U uses an internally illuminating lamp post to improve illumination uniformity. These solutions all employ independent designs for light field distribution and flow field structure, failing to achieve synergistic matching between light and flow space. The introduction of the swirling flow field does not address the problem of blind spots in illumination, and the optimization of the light source layout ignores the impact of fluid turbulence on light transmission, resulting in limited light energy utilization efficiency and difficulty in simultaneously meeting the dual requirements of strong swirling shear and uniform light irradiation.

[0004] In terms of multi-unit parallel amplification, existing technologies such as CN117963840A use multiple parallel reaction sub-modules to achieve hydrogen production performance regulation, while CN101973519B uses optical fibers to distribute concentrated sunlight to multiple reaction units. These technologies struggle to guarantee the uniformity of operating conditions among the parallel units—the former lacks a fluid distribution structure, leading to significant differences in the flow field between units; the latter's external optical splitter cannot guarantee the consistency of light intensity received by each unit, and the external light source introduces coupling losses, resulting in uneven performance among units during amplification and hindering the linear improvement of processing capacity.

[0005] In terms of decoupling control of reaction-separation, the reaction process and separation process in existing technologies are mutually constrained and fail to achieve true decoupling. For example, CN119503947A integrates the reaction and separation in the same flow field, which leads to mutual constraints between reaction conditions and separation efficiency. CN111874864B connects the reactor and separation device directly in series. Although spatial separation is achieved, the discharge fluctuation still directly affects the separation stability, and the catalyst cannot be circulated in a controlled manner, making it difficult to maintain the catalyst activity in long-term operation.

[0006] It is worth noting that a common design philosophy in existing technologies is that photocatalytic reactions and product separation should be integrated into the same unit or kept tightly coupled to avoid energy loss and catalyst sedimentation risks during material transport. However, after in-depth research, the inventors of this application discovered that the intrinsic kinetics of photocatalytic hydrogen production (millisecond to second-level) differs significantly in time scale from the physical processes of gas-liquid separation (sub-millisecond-level). Forcibly coupling the reaction and separation processes leads to a mutual constraint between reaction conditions and separation efficiency. Existing technologies have not recognized this time scale difference, nor have they provided an effective solution.

[0007] In summary, existing photocatalytic hydrogen production technologies still have shortcomings in areas such as photo-fluid synergistic enhancement, uniformity of multi-unit parallel operation, and decoupled control of reaction and separation. In particular, how to avoid mutual interference between reaction and separation processes while enhancing mass transfer, and how to achieve independent optimization of reaction conditions and separation efficiency through modular design, have not yet been systematically resolved. To address these issues, this invention provides a photocatalytic device and method for two-stage tandem hydrogen production and extraction enhanced by cyclone flow. 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 photocatalytic device and method for two-stage tandem hydrogen production and extraction enhanced by swirling flow. This method physically separates and functionally decouples the chemical reaction and physical separation processes. By constructing a strong swirling flow field, a uniform light field, and a modular parallel structure, it synergistically enhances the photocatalytic hydrogen evolution process and product purification efficiency, thereby significantly improving the device's processing capacity, system stability, and operational flexibility.

[0009] This invention provides the following technical solution: In a first aspect, embodiments of this application provide a photocatalytic device for two-stage tandem cyclone enhanced hydrogen production and extraction, the photocatalytic device comprising a photocyclone hydrogen production device and a cyclone hydrogen extraction device connected in series and physically separated along the material flow direction; The photocyclone hydrogen production device includes: A swirl reaction unit includes multiple swirl reactors connected in parallel. The feed distribution unit has a tangential feed inlet and multiple discharge outlets, which are respectively connected to the inlet of each of the cyclone reactors and are used to distribute catalyst slurry to each of the cyclone reactors. The light source introduction unit includes an external light source and multiple built-in light guides. One end of each light guide is disposed inside the corresponding swirling reactor, and the other end is connected to the external light source. The hydrocyclone hydrogen extraction device includes: The hydrocyclone hydrogen extraction unit includes multiple hydrocyclone separators arranged in parallel in a circumferential array. Each hydrocyclone separator has a tangential feed inlet, a top overflow inlet, and a bottom underflow inlet. The tangential feed inlet is in fluid communication with the outlet of the hydrocyclone reactor. A gaseous product collection unit is connected to the top overflow port; The liquid phase recycling unit connects the bottom underflow port to the tangential feed port of the feed distribution unit, forming a circulation path for the catalyst slurry.

[0010] In some embodiments of the first aspect, an intermediate buffer tank is provided between the photocyclone hydrogen production device and the cyclone hydrogen extraction device. The inlet of the intermediate buffer tank is connected to the outlet of the cyclone reactor, and the side or bottom outlet of the intermediate buffer tank is connected to the tangential feed port of the cyclone separator via a transfer pump. The intermediate buffer tank is equipped with a liquid level detection and control device, which is electrically connected to the transfer pump and is used to adjust the operating parameters of the transfer pump according to the liquid level in the tank.

[0011] In some embodiments of the first aspect, the feeding and dispensing unit is a feeding tank, the bottom of which is connected to the tangential feeding port, and the periphery of which is connected to each of the discharge ports; The cyclone reaction unit includes a cyclone tank, and the cyclone hydrogen extraction unit includes a separation tank; The cyclone tank has multiple cyclone inlets on its periphery and a cyclone outlet at its top. The separation tank is formed with an overflow chamber, a feed buffer chamber, and an underflow chamber arranged sequentially from top to bottom and separated from each other. The cyclone inlet is connected to the corresponding outlet of the cyclone reactor, the cyclone outlet is connected to the feed buffer chamber through an intermediate buffer tank, the tangential feed inlet of the cyclone separator is connected to the feed buffer chamber, the overflow chamber is connected to the top overflow port of the cyclone separator and the gas phase product collection unit respectively; the underflow chamber is connected to the bottom underflow port of the cyclone separator and the liquid phase recycling unit respectively.

[0012] In some embodiments of the first aspect, the inlet of each of the cyclone reactors is connected to the corresponding outlet via a regulating valve.

[0013] In some embodiments of the first aspect, the built-in light guide rod is provided with a light scattering microstructure at one end inside the swirling reactor; the light scattering microstructure is selected from at least one of surface roughening structure, microprism array structure, light scattering coating, and fiber grating bundle structure, so that the light intensity non-uniformity on the radial cross section of the swirling reactor is less than 10%.

[0014] Secondly, embodiments of this application also provide a photocatalytic method for a two-stage tandem process of cyclone-enhanced hydrogen production and extraction, utilizing the apparatus described in any one of the above embodiments, comprising: S100: External light source is introduced through the built-in light guide rod, and a uniform light field is formed on the radial section of the cyclone reactor; S200: The catalyst slurry is injected into the cyclone reactor of the photocyclone hydrogen production device to form a cyclone field, so that the catalyst particles dynamically update the surface active sites under the action of centrifugal force, and carry out photocatalytic hydrogen production reaction under the irradiation of an external light source to obtain a gas-liquid mixture. S300: The gas-liquid mixture is fed into the hydrocyclone separator of the hydrocyclone hydrogen extraction device for gas-liquid separation to obtain hydrogen products and a slurry rich in catalyst. S400: Collect the hydrogen products and return at least a portion of the catalyst-rich slurry to the feed distribution unit of the photocyclone hydrogen production device via the liquid phase recycling unit.

[0015] In some embodiments of the second aspect, in S200, the average residence time of the catalyst slurry in the cyclone reactor is 30 s to 300 s, and the solid content of the slurry is 0.1 wt% to 5.0 wt%.

[0016] In some embodiments of the second aspect, in S400, 10% to 80% of the hydrogen-extracted catalyst slurry is returned to the feed distribution unit of the photocyclone hydrogen production device, while another portion of the slurry is discharged and fresh catalyst slurry is added to maintain the catalyst activity and concentration balance.

[0017] In some embodiments of the second aspect, the external light source is sunlight or an artificial light source.

[0018] In some embodiments of the second aspect, the liquid medium used in the reaction is deionized water or wastewater containing degradable organic matter.

[0019] The embodiments of the present invention have the following advantages: The photocatalytic device for enhanced hydrogen production and extraction, provided by this invention, employs a circumferentially parallel multi-tube cyclone reactor design. By increasing the number of parallel reactors, the processing capacity of the device can be linearly increased, breaking through the capacity limit of a single-tube reactor. The modular design allows the scale of the reaction and separation modules to be independently adjusted according to needs, resulting in high operational flexibility. Through the circumferentially parallel multi-tube design and the uniform distribution effect of the feed distribution unit, uniform flow distribution among the cyclone reactors can be achieved.

[0020] The high shear force generated by the strong swirling flow field not only promotes reactant mixing and mass transfer, but also dynamically reconstructs the catalyst surface, continuously exposing and activating active sites, significantly improving the photocatalytic reaction rate and hydrogen yield. The synergistic effect of the strong swirling flow field and the uniform light field can significantly enhance the photocatalytic reaction rate and hydrogen yield.

[0021] The two-stage series modular design, combined with the buffering and level control functions of the intermediate buffer tank, achieves true decoupling of the two core processes: photocatalytic hydrogen production and hydrogen purification. The reaction residence time of the hydrogen production module and the separation parameters of the hydrogen purification module can be independently set under the buffering effect of the intermediate buffer tank, without mutual constraints. The intermediate buffer tank also provides pressure buffering and safety relief functions, significantly improving the system's operational stability, operational flexibility, and inherent safety. Furthermore, the intermediate buffer tank also solves the problem in traditional series systems where upstream discharge fluctuations directly affect downstream separation stability.

[0022] The coaxial integration of the built-in light guide rod and the cyclone reactor enables efficient light energy introduction and uniform dispersion. This effectively solves the light attenuation problem of traditional side-illuminated or bottom-illuminated reactors. The efficient cyclone gas-liquid separation technology ensures the rapid collection of high-purity hydrogen, while the efficient recycling of the catalyst slurry reduces catalyst consumption and operating costs.

[0023] The device structure and method are applicable to a variety of light sources and reaction media. It can utilize solar energy for green hydrogen production and treat wastewater containing organic matter to achieve synergistic environmental remediation and resource recovery.

[0024] 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

[0025] 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.

[0026] Figure 1 This is a schematic diagram of the overall structure of a photocatalytic device for two-stage tandem hydrogen production and extraction, as described in one embodiment of the present invention. Figure 2 This is a schematic diagram of the overall structure of a photocatalytic hydrogen production device in one embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of a cyclone reactor in one embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a hydrocyclone hydrogen extraction device in one embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a cyclone separator in one embodiment of the present invention; Figure 6 This is a flowchart illustrating the principle of a photocatalytic method for two-stage tandem hydrogen production and extraction enhanced by cyclone enhancement, as described in one embodiment of the present invention.

[0027] Explanation of key component symbols: 1-Feed distribution unit; 11-Mixing pump; 12-Feed distribution chamber; 2-Light source introduction unit; 21-Light guide rod; 3-Swirl reaction unit; 31-Swirl reactor; 32-Swirl tank; 4-Intermediate buffer tank; 5-Hydrocyclone hydrogen extraction unit; 51-Overflow chamber; 52-Hydrocyclone separator; 521-Top overflow port; 522-Tangential feed port; 523-Bottom underflow port; 53-Feed buffer chamber; 54-Underflow chamber; 6-Gas-phase product collection unit; 7-Sewage outlet; 8-Liquid phase recycling unit. Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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 in the template description 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.

[0033] In related technologies, the inventors of this application, after in-depth research, discovered that existing photocatalytic hydrogen production technologies generally suffer from key bottlenecks in practical applications, such as uneven light energy distribution, low mass transfer efficiency, difficulty in gas-liquid separation, and limited device scale-up. Although optimizing the light source layout, introducing stirring, or adding external separation equipment can improve local performance to some extent, it is often difficult to achieve synergistic enhancement of multiple fields—light, flow, reaction, and separation—at the system level. Especially in suspended catalyst systems, how to maintain high catalyst dispersibility and activity while achieving rapid separation of product hydrogen and stable recycling of the catalyst is the core challenge restricting the large-scale application of this technology.

[0034] Based on this, and after systematically analyzing the shortcomings of existing technologies, this invention proposes a two-stage tandem photocatalytic device and method for enhanced hydrogen production and extraction via swirling flow. This invention achieves true decoupling of the reaction and separation processes through the physical separation of the photocatalytic hydrogen production module and the hydrogen purification module, and the introduction of an intermediate buffer tank 4. It should be noted that the "decoupling" in this invention means that the reaction residence time of the photocatalytic hydrogen production module and the separation parameters of the hydrogen purification module can be independently optimized under the constraints of system material balance, and there is no direct coupling constraint between the two. The circumferentially parallel multi-tube swirling reactor 31 and the array-arranged swirling separator 52 are designed in a coordinated manner to achieve efficient integration and independent control of photocatalytic hydrogen production and hydrogen purification. Combined with the uniform light field distribution achieved by the coaxial arrangement of the built-in light guide rod 21 and the swirling reactor 31, and the dynamic reconstruction mechanism of the catalyst surface by the strong swirling flow field, the light energy utilization efficiency and hydrogen evolution reaction rate are significantly improved. Meanwhile, by recycling and adjusting the concentration of the catalyst slurry, the stability and activity of the system are maintained during long-term operation, providing a new technical path for the industrial application of photocatalytic hydrogen production technology.

[0035] In the implementation of this invention, the tangential flow velocity within the cyclone reactor 31 is a key operating parameter affecting the photo-fluid synergistic enhancement effect. When the tangential flow velocity is too low, the cyclone field intensity is insufficient to drive the catalyst particles to undergo surface dynamic reconstruction, resulting in insufficient exposure of active sites and a limited hydrogen evolution reaction rate. When the tangential flow velocity is too high, not only does energy consumption increase significantly, but it also exacerbates collision and wear between catalyst particles, shortening the catalyst's lifespan. Considering both the reaction enhancement effect and operational economy, the tangential flow velocity is preferably controlled within the range of 1.5-3.0 m / s. Similarly, through the intermediate buffer tank 4 located between the two modules and its level-controlled transfer pump, the outlet flow rate of the hydrogen production module and the inlet flow rate of the hydrogen extraction module can be independently adjusted. Therefore, the tangential flow velocity within the cyclone separator 52 can be independently set according to the gas-liquid separation efficiency requirements, independent of the flow velocity within the reactor, demonstrating the decoupling design advantage of this invention.

[0036] like Figures 1 to 5 As shown, in order to solve the above-mentioned technical problems, this application provides a photocatalytic device for two-stage tandem hydrogen production and extraction, wherein the photocatalytic device includes a photocyclone hydrogen production device and a cyclone hydrogen extraction device that are connected in series and physically separated along the material flow direction; The photocyclone hydrogen production device includes: The swirling reaction unit 3 includes multiple swirling reactors 31 arranged in parallel. The feed distribution unit 1 has a tangential feed inlet and multiple discharge outlets, which are respectively connected to the inlet of each of the cyclone reactors 31 and are used to distribute catalyst slurry to each of the cyclone reactors 31. The light source introduction unit 2 includes an external light source and multiple built-in light guide rods 21. One end of each light guide rod 21 is disposed inside the corresponding swirling reactor 31, and the other end is connected to the external light source. The hydrocyclone hydrogen extraction device includes: The hydrocyclone hydrogen extraction unit 5 includes multiple hydrocyclone separators 52 arranged in parallel along a circumferential array. Each hydrocyclone separator 52 has a tangential feed inlet 522, a top overflow outlet 521, and a bottom underflow outlet 523. The tangential feed inlet 522 is in fluid communication with the outlet of the hydrocyclone reactor 31. The gaseous product collection unit 6 is connected to the top overflow port 521; The liquid phase recycling unit 8 is connected to the bottom underflow port 523 and the tangential feed port of the feed distribution unit 1 to form a circulation path for the catalyst slurry.

[0037] In these embodiments, the present invention provides a photocatalytic device for two-stage tandem hydrogen production and extraction enhanced by cyclone flow, comprising a photocyclone hydrogen production device and a cyclone hydrogen extraction device connected in series and physically separated along the material flow direction.

[0038] The photocyclone hydrogen production device includes: Swirl reactor unit 3: It consists of multiple swirl reactors 31 connected in parallel, and each swirl reactor 31 is arranged symmetrically in a circle; Feed distribution unit 1: It is equipped with one tangential feed port and multiple discharge ports. Each discharge port is connected to the tangential inlet of each cyclone reactor 31 through distribution pipelines of equal length and diameter to ensure uniform distribution of catalyst slurry. Light source introduction unit 2: includes a set of ultraviolet LED external light source and multiple quartz light guide rods 21. One end of each light guide rod 21 is inserted into the central axis position of the corresponding swirling reactor 31, and the other end is coupled to the beam splitting output end of the external light source to achieve uniform internal irradiation.

[0039] The hydrocyclone hydrogen extraction device includes: Hydrogen extraction unit 5: includes multiple hydrocyclones 52 arranged in a circumferential array. Each hydrocyclone 52 has a tangential feed inlet 522, a top overflow inlet 521, and a bottom underflow inlet 523. The outlet of each hydrocyclone reactor 31 is directly connected to the tangential feed inlet 522 of the corresponding hydrocyclone 52 through a pipeline to form a strong swirling field. Gas phase product collection unit 6: It is an annular gas collection chamber connected to the top overflow port 521 of all cyclone separators 52, and is used to collect high-purity hydrogen. Liquid phase recycling unit 8: After the bottom flow ports 523 of each hydrocyclone 52 are merged, the flow is sent back to the tangential feed port of the feed distribution unit 1 through a circulation pump to form a closed loop, with no catalyst loss.

[0040] During operation, the catalyst slurry enters through the tangential feed inlet, is distributed, and then injected tangentially into each cyclone reactor 31, forming a high-speed rotating flow field inside. Simultaneously, the light guide rod 21 provides uniform axial illumination, achieving synergistic enhancement of light and flow. The reacted gas-liquid mixture enters the cyclone separator 52, where centrifugal force achieves efficient gas-liquid separation. The gas is discharged from the top overflow port 521, while the liquid, carrying the catalyst, returns to the system from the bottom. This design achieves complete spatial and functional decoupling of the reaction and separation processes, avoiding reaction fluctuations caused by separation disturbances in traditional integrated designs.

[0041] In some embodiments, an intermediate buffer tank 4 is provided between the photocyclone hydrogen production device and the cyclone hydrogen extraction device. The inlet of the intermediate buffer tank 4 is connected to the outlet of the cyclone reactor 31, and the top outlet of the intermediate buffer tank 4 is connected to the tangential feed port 522 of the cyclone separator 52 via a transfer pump. The intermediate buffer tank 4 is equipped with a liquid level detection and control device, which is electrically connected to the transfer pump and is used to adjust the operating parameters of the transfer pump according to the liquid level in the tank.

[0042] In these embodiments, an intermediate buffer tank 4 is provided between the photocyclone hydrogen production device and the cyclone hydrogen extraction device. The inlet of the intermediate buffer tank 4 is connected to the outlet of all cyclone reactors 31 through a manifold, and is used to temporarily store the gas-liquid-solid three-phase mixture after the reaction; its top is provided with an outlet, which is connected to the tangential feed port 522 of each cyclone separator 52 via a variable frequency delivery pump.

[0043] The intermediate buffer tank 4 is equipped with a liquid level detection and control device, such as an ultrasonic level gauge or a differential pressure level sensor, to monitor the liquid level in the tank in real time. This liquid level detection and control device is electrically connected to the frequency converter of the delivery pump, forming a closed-loop control system. When the liquid level is higher than the set upper limit (e.g., 80% of the tank volume), the system automatically increases the speed of the delivery pump to accelerate the feeding rate to the cyclone separator 52; when the liquid level is lower than the lower limit (e.g., 30%), the pump speed is reduced or operation is stopped to prevent the cyclone separator 52 from experiencing gas leakage or dry running due to insufficient feed.

[0044] Photocatalytic reactions are affected by factors such as light intensity and catalyst activity, and the gas production rate may fluctuate in the short term. The buffer tank can smooth out changes in the discharge flow rate, ensuring that the hydrocyclone separator 52 always operates under stable conditions. During start-up, shutdown, or load adjustment phases, the buffer tank can serve as a temporary storage unit to prevent overflow or cavitation caused by inconsistent response speeds between upstream and downstream units. By maintaining a constant feed flow rate to the hydrocyclone separator 52, the gas-liquid separation efficiency is significantly improved.

[0045] In some embodiments, the feeding and distributing unit 1 is a feeding tank, the bottom of which is connected to the tangential feeding port, and the periphery of which is connected to each of the discharge ports; The cyclone reaction unit 3 includes a cyclone tank 32, and the cyclone hydrogen extraction unit 5 includes a separation tank. The cyclone tank 32 has multiple cyclone inlets on its periphery and a cyclone outlet at its top. The separation tank is formed with an overflow chamber 51, a feed buffer chamber 53, and an underflow chamber 54 arranged sequentially from top to bottom and separated from each other. The cyclone inlet is connected to the outlet of the corresponding cyclone reactor 31, the cyclone outlet is connected to the feed buffer chamber 53 through the intermediate buffer tank 4, the tangential feed inlet 522 of the cyclone separator 52 is connected to the feed buffer chamber 53, the overflow chamber 51 is connected to the top overflow port 521 of the cyclone separator 52 and the gas phase product collection unit 6 respectively; the underflow chamber 54 is connected to the bottom underflow port 523 of the cyclone separator 52 and the liquid phase recycling unit 8 respectively.

[0046] In these embodiments, the photocatalytic device of the present invention adopts a highly integrated tank design, including a feed tank, a cyclone tank 32, an intermediate buffer tank 4, and a separation tank. The components are connected by internal or short-distance pipelines, which significantly improves the system's compactness and operational stability.

[0047] The feed distribution unit 1 is a vertical cylindrical feed tank with a tangential feed port at the center of its bottom, which is connected to the liquid phase recycling unit 8; multiple discharge ports are evenly distributed on its periphery for distributing catalyst slurry downstream.

[0048] The swirling reaction unit 3 includes an integral swirling tank 32, which integrates multiple parallel swirling reaction channels (i.e., equivalent to multiple swirling reactors 31). The swirling tank 32 has multiple swirling inlets on its periphery, which are connected to the outlets of the feed tank through short pipes to achieve tangential feeding and form a strong swirling field; the top center of the swirling tank 32 has a uniform swirling outlet for discharging the gas-liquid-solid three-phase mixture after the reaction.

[0049] The hydrocyclone hydrogen extraction unit 5 includes a separation tank, which is internally divided into three sealed and isolated chambers from top to bottom by two horizontal partitions: Overflow chamber 51: Located at the top, with a gas collection port at the top; Feed buffer chamber 53: located in the middle; Bottom flow chamber 54: Located at the bottom, with a drain port at the bottom.

[0050] The catalyst slurry enters from the bottom of the feed tank tangentially towards the feed inlet, enters the cyclone reactor 31 through the peripheral discharge outlet, and then enters the cyclone inlet of the cyclone tank 32, where it undergoes a photocatalytic water splitting reaction under the irradiation of the built-in light guide rod 21. The reaction products flow out from the cyclone outlet at the top of the cyclone tank 32 and first enter the intermediate buffer tank 4 for gas-liquid temporary storage and flow homogenization. The outlet of the intermediate buffer tank 4 sends the mixture into the feed buffer chamber 53 of the separator via a variable frequency delivery pump. This feed buffer chamber 53 is directly connected to the tangential feed inlets 522 of multiple cyclone separators 52.

[0051] It should be noted that the hydrocyclone separator 52 is installed inside the separation tank. The tangential feed port 522 of the hydrocyclone separator 52 is directly exposed in the feed buffer chamber 53, the bottom underflow port 523 is directly exposed in the underflow chamber 54, and the top overflow port 521 is directly exposed in the overflow chamber 51.

[0052] The hydrogen separated by each cyclone separator 52 rises from the top overflow port 521 into the overflow chamber 51 at the top of the separator tank, and flows into the gas phase product collection unit 6 through the gas collection interface.

[0053] The separated catalyst-containing slurry flows from the bottom underflow port 523 of the hydrocyclone 52 into the underflow chamber 54 at the bottom of the separator tank, and then returns to the tangential feed port of the feed tank through the pipeline to complete the cycle.

[0054] The above configuration reduces external bends and long pipelines, lowering pump power consumption. The intermediate buffer tank 4 smooths out reaction fluctuations, and the feed buffer chamber 53 balances multiple feeds, providing dual protection for the stable operation of the hydrocyclone separator 52. The overflow chamber 51, feed buffer chamber 53, and underflow chamber 54 are strictly separated to avoid gas-phase backmixing or liquid-phase short-circuiting, ensuring stable hydrogen purity.

[0055] In this embodiment, the outer wall of the cyclone reactor 31 is made of quartz glass to transmit light.

[0056] It should be noted that a baffle is installed inside the separator to separate the overflow chamber 51, the feed buffer chamber 53, and the underflow chamber 54. The cyclone separator 52 is installed on the baffle, and the rated number can be changed by disassembling and assembling the cyclone separator 52 and the baffle to adapt to long-term or phased changes in the upstream reaction capacity.

[0057] In some embodiments, the inlet of each of the cyclone reactors 31 is connected to the corresponding outlet via a regulating valve.

[0058] In these embodiments, to further improve the uniformity of operation and the flexibility of operation of the multi-channel parallel system, the inlet of each of the cyclone reactors 31 is connected to the outlet of the corresponding feed tank through a regulating valve.

[0059] Specifically, an electrically operated proportional control valve is installed downstream of each discharge port of the feed tank and upstream of each cyclone inlet of the cyclone tank 32. This control valve is a corrosion-resistant pneumatic / electric V-type ball valve with continuous opening adjustment capability and is equipped with a position feedback sensor.

[0060] In addition, the introduction of regulating valves also supports the on-demand start-up and shutdown of some reaction units, such as activating only two channels during periods of low light intensity, reducing the energy consumption of the circulating pump, and achieving flexible production capacity adjustment.

[0061] In some embodiments, the built-in light guide rod 21 has a light scattering microstructure at one end inside the swirling reactor 31; the light scattering microstructure is selected from at least one of surface roughening structure, microprism array structure, light scattering coating, fiber optic grating bundle structure or volume grating structure, so that the light intensity non-uniformity on the radial cross section of the swirling reactor 31 is less than 10%.

[0062] In these embodiments, to address the problem of excessive radial light intensity gradient caused by beam concentration within the swirling reactor 31, the present invention provides a light scattering microstructure at one end (i.e., the light-emitting end) of the built-in light guide rod 21 located inside the swirling reactor 31, so as to achieve uniform distribution of light energy in the reaction area.

[0063] The built-in light guide rod 21 is made of fused silica, with one end coupled to an external ultraviolet LED light source and the other end extending into the central axis of the cyclone reactor 31. Light scattering microstructures are integrated on the end face and near-end sidewall region of this extended end. The light scattering microstructures are selected from at least one of the following: Surface roughening structure: A random array of micro-pits is formed on the end face of the light guide rod 21 by femtosecond laser etching; Microprism array structure: a square pyramidal microstructure is imprinted on the end face; Light scattering coating: Coated with composite nanoparticles, with refractive index matching the substrate; Fiber Bragg grating bundle structure: Multiple short-period fiber Bragg gratings are connected in parallel at the end of the light guide rod 21 to achieve multi-angle diffraction of light; Volume grating structure: A periodic refractive index modulation structure formed inside the light guide rod 21 by ultraviolet laser writing or femtosecond laser direct writing, which diffracts the light energy transmitted along the axial direction and couples it out radially.

[0064] The principle behind the aforementioned light-scattering microstructures improving the uniformity of light distribution lies in the fact that light energy transmitted along the axial direction of the light guide rod 21 is scattered or diffracted when it encounters these microstructures, and some of the light energy is coupled out of the light guide rod 21 and radiated radially. By rationally designing the axial density distribution of the microstructures (e.g., lower density at the inlet end and higher density at the end), the attenuation of light energy along the path can be compensated, ensuring that the radially emitted light intensity remains uniform along the axial direction. Using the above structure, the light intensity non-uniformity on the radial cross-section of the cyclone reactor 31 can be less than 10% (i.e., the ratio of the difference between the maximum and minimum light intensities to the average light intensity is less than 0.1).

[0065] The number of cyclone reactors 31 connected in parallel in the cyclone reaction unit 3 can be changed from 1 to 20 to adapt to different production capacity requirements. Specific changes include: (1) Configurable changes during the manufacturing stage: prefabricate the required number of cyclone reactors 31 by designing different numbers of discharge ports; (2) Adjustable changes during the operation stage: set a shut-off valve on the inlet pipe of each cyclone reactor 31, and adjust the actual number of operating reactors by opening and closing the valves; (3) Modular expansion changes: reserve expansion interfaces on the feed chamber, distribution chamber and collection chamber, and add additional cyclone reactors 31 on the reserved interfaces when production expansion is required to achieve online expansion.

[0066] During operation, the catalyst slurry is first evenly distributed to each cyclone reactor 31 through the feed distribution unit 1. After the slurry is injected, a strong swirling field is formed inside the cyclone reactor 31. At the same time, light energy emitted by an external light source is introduced into the reaction zone through the built-in light guide rod 21 that runs through each cyclone reactor 31. The built-in light guide rod 21 is coaxially arranged with the cyclone reactor 31, and the light scattering microstructure on the surface of the light guide rod 21 enables the light energy to be evenly distributed in the radial direction of the reactor, so that the light intensity non-uniformity on the radial cross section of the cyclone reactor 31 is less than 10%. Under the synergistic effect of the uniform light field and the strong swirling field, the catalyst particles are subjected to high shear force and undergo surface dynamic reconstruction, the active sites are fully exposed and effectively excited, driving the photocatalytic water splitting reaction to continuously generate hydrogen. The gas-liquid mixture generated by the reaction flows out, is buffered by the intermediate buffer tank 4, and is then transported to the feed buffer chamber 53 of the hydrogen extraction module, and enters multiple cyclone separators 52 arranged in a circular array at a tangential velocity. Inside the cyclone separator 52, the centrifugal force generated by the high-speed swirling flow causes gaseous hydrogen to rapidly gather towards the center and enter the gaseous product collection unit 6 from the top overflow port 521. The catalyst-rich liquid phase moves downward along the wall and enters the liquid phase recycling unit 8 through the bottom underflow port 523. Most of the catalyst slurry is returned to the feed distribution unit 1 of the photocatalytic hydrogen production module via the circulation pipeline, where it mixes with fresh slurry and participates in the reaction again. A small amount of slurry is discharged through the drain port 7 to maintain concentration balance, while fresh catalyst is added to maintain reaction activity. The entire device, through a two-stage series modular layout, achieves physical separation and process connection between the photocatalytic hydrogen production reaction and hydrogen purification. The reaction residence time in the cyclone reactor 31 and the separation parameters in the cyclone separator 52 can be set independently without mutual constraints. Each unit operates continuously and collaboratively to ensure the stable and efficient photocatalytic hydrogen production process.

[0067] like Figure 6 As shown, in some embodiments, this application also provides a photocatalytic method for a two-stage tandem process of cyclone-enhanced hydrogen production and extraction, utilizing the apparatus described in any one of the above embodiments, comprising: S100: An external light source is introduced through the built-in light guide rod 21, and a uniform light field is formed on the radial section of the swirling reactor 31.

[0068] When an external light source is turned on, light energy is guided into each swirling reactor 31 via the built-in light guide rod 21. The end of the light guide rod 21 is equipped with a light-scattering microstructure, ensuring uniform irradiation of light across the radial cross-section of the swirling reactor 31. Verification using a CCD light intensity imaging system shows that the light intensity non-uniformity across this cross-section is less than 10%.

[0069] S200: The catalyst slurry is injected into the cyclone reactor 31 of the photocyclone hydrogen production device to form a cyclone field, so that the catalyst particles dynamically update the surface active sites under the action of centrifugal force, and carry out photocatalytic hydrogen production reaction under the irradiation of an external light source to obtain a gas-liquid mixture.

[0070] The catalyst slurry is injected into the cyclone reactor 31 at a tangential flow rate of 1.5-3.0 m / s to form a strong cyclone field, which causes the catalyst particles to dynamically renew the surface active sites under the action of centrifugal force, and at the same time, they are excited by a uniform light field to carry out the photocatalytic hydrogen production reaction.

[0071] S300: The gas-liquid mixture is fed into the cyclone separator 52 of the cyclone hydrogen extraction device for gas-liquid separation to obtain hydrogen products and a catalyst-rich slurry.

[0072] The generated gas-liquid mixture is injected into the cyclone separator 52, and the hydrogen gas is separated from the catalyst slurry by utilizing the cyclone field. The inlet tangential flow rate of the cyclone separator 52 is set according to the separation requirements, and the inlet tangential flow rate of the cyclone reactor 31 is set according to the reaction requirements. Both are adjusted separately.

[0073] S400: Collect the hydrogen products and send at least a portion of the catalyst-rich slurry back to the feed distribution unit 1 of the photocyclone hydrogen production device through the liquid phase recycling unit 8.

[0074] The separated hydrogen gas is collected, and the catalyst-rich slurry portion after separation is returned to the feed distribution unit 1 of the photocatalytic hydrogen production module through the liquid phase recycling unit 8 to participate in the recycling reaction.

[0075] It should be noted that the tangential flow velocity is controlled within the range of 1.5-3.0 m / s: below 1.5 m / s, the swirling flow field intensity is insufficient to drive the dynamic reconstruction of the catalyst particle surface; above 3.0 m / s, energy consumption increases significantly and catalyst particle wear intensifies. A uniform radial strong light field covers the entire flow channel. Under the action of swirling shear force, the catalyst particles are highly dispersed and continuously renew their surfaces, while being uniformly excited by the light field, efficiently producing hydrogen and forming tiny hydrogen bubbles. The gas-liquid mixture after the reaction flows out from the swirling outlet and enters the subsequent functional unit.

[0076] In some embodiments, in S200, the average residence time of the catalyst slurry in the cyclone reactor 31 is 30 s to 300 s, and the solid content of the slurry is 0.1 wt% to 5.0 wt%.

[0077] In these embodiments, to balance photocatalytic reaction efficiency, catalyst utilization economy, and swirling field stability, the average residence time of the catalyst slurry in the swirling reactor 31 is controlled between 30 s and 300 s, and the slurry solid content is controlled between 0.1 wt% and 5.0 wt%. This parameter window represents the optimal balance range for achieving high hydrogen production rates and low energy consumption operation.

[0078] The residence time is 30 s and the solid content is 0.1 wt%. Under these conditions, the catalyst dosage is low and the system pressure is low, making it suitable for high light intensity and fast reaction scenarios, but the total hydrogen production is limited.

[0079] The residence time is 120 s, and the solid content is 1.0 wt%. This is the recommended operating condition. Photogenerated carriers have sufficient time to participate in the reaction, and the swirling flow field effectively suspends the particles, resulting in optimal stability.

[0080] The residence time is 300 s, and the solid content is 5.0 wt%. It is suitable for scenarios with low light intensity or high production capacity requirements. When the solid content is greater than 5.0 wt%, particle sedimentation or light guide rod 21 is prone to occur in the swirling field, resulting in light intensity attenuation; when the residence time is less than 30 s, the reaction conversion rate is insufficient, and the hydrogen yield drops sharply.

[0081] The above results demonstrate that the method of this invention can operate stably and efficiently within a residence time range of 30 to 300 s and a solid content range of 0.1 to 5.0 wt%, and can be flexibly adapted to different lighting conditions and production capacity requirements by adjusting these two parameters. Furthermore, the residence time is controlled by adjusting the feed flow rate and the effective volume of the cyclone reactor 31, and the solid content is controlled by adjusting the slurry concentration and the circulating dilution ratio, making the operation simple.

[0082] In some embodiments, in S400, 10% to 80% of the hydrogen-extracted catalyst slurry is returned to the feed distribution unit 1 of the photocyclone hydrogen production device, while another portion of the slurry is discharged and fresh catalyst slurry is added to maintain the catalyst activity and concentration balance.

[0083] In these embodiments, to balance catalyst utilization efficiency and long-term system stability, 10% to 80% of the catalyst-rich slurry discharged from the cyclone hydrogen extraction device is returned to the feed distribution unit 1 of the photocyclone hydrogen production device, while the remaining 20% ​​to 90% of the slurry is discharged from the system as a discharge, and an equal volume of fresh catalyst slurry is added simultaneously, thereby dynamically maintaining the catalyst activity, concentration and impurity level in the reaction system within the optimal range.

[0084] During photocatalysis, reaction byproducts are gradually adsorbed or photo-corrosion occurs on the catalyst surface, leading to passivation of active sites. Simultaneously, small particles may be lost due to aggregation or wear. If 100% full recycling is used, impurities will continuously accumulate, causing irreversible activity degradation; frequent complete replacement is costly and complex. Therefore, partial discharge combined with partial replenishment is an economical and efficient balancing solution. When the recycling ratio is greater than 80% (e.g., 95%), byproduct accumulation after 7 days leads to excessive pH drop and a decrease in hydrogen production rate; when the recycling ratio is less than 10% (e.g., 5%), catalyst costs increase, and system concentration fluctuations are large, making control difficult.

[0085] The above results indicate that a cycle ratio range of 10% to 80% can effectively balance the three objectives of catalyst activity maintenance, operating cost, and operational stability.

[0086] In some embodiments, the external light source is sunlight or an artificial light source. Artificial light sources include LEDs, xenon lamps, etc.

[0087] In some embodiments, the liquid medium used in the reaction is deionized water or wastewater containing biodegradable organic matter.

[0088] For example, in an industrial application of photocatalytic hydrogen production in a fine chemical industrial park, according to the method of the present invention, a two-stage photocatalytic device for enhanced hydrogen production and extraction is used to conduct a photocatalytic hydrogen production treatment experiment on methanol-containing organic wastewater discharged from a chemical plant in the park. This achieves wastewater purification while recovering hydrogen energy. 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 by the chemical plant before the reaction are shown in Table 1 below.

[0089]

[0090] Note: This wastewater is a medium-concentration organic wastewater generated from the methanol synthesis and distillation process. 2. Photocatalytic experimental setup for two-stage tandem hydrogen production and extraction enhanced by cyclone flow The experimental setup employs a two-stage, series-connected modular layout. The photocatalytic hydrogen production section comprises ten circumferentially parallel swirling reactors 31, evenly distributed around the circumference and integrated with the collection chamber via a feed distribution cavity 12. Each swirling reactor 31 has an inner diameter of 60 mm and a height of 600 mm, and is made of high-transmittance quartz glass. An inlet with a cross-sectional area of ​​20 mm² is located at the bottom of each reactor. An internal light guide rod 21 is inserted through the central axis of each swirling reactor 31, coaxially positioned with the reactor. The light guide rod 21 has a diameter of 12 mm and a length of 620 mm, and its surface is covered with light-scattering microstructures. These microstructures are formed using a chemical etching method to roughen the surface, achieving an average roughness Ra of 1 to 5 μm, causing diffuse scattering of light at the interface. Simultaneously, along the axial direction of the light guide rod 21, the density of the microstructures gradually increases from the light source inlet to the free end, with 20 scattering points per centimeter at the inlet and 80 scattering points per centimeter at the outlet, compensating for light energy attenuation along the path. In addition, the surface of the light guide rod 21 is also coated with a wear-resistant coating (such as a diamond-like carbon coating) to withstand the wear of the catalyst slurry in a strong swirling flow field. One end of the light guide rod 21 is connected to an external LED light source via an optical fiber interface. The external light source has a power of 1000 W and a spectral range of 350-550 nm. The other end is a free end.

[0091] The hydrogen purification module is equipped with 13 circumferentially parallel micro-cyclone separators 52, integrated through a shared overflow chamber 51, feed buffer chamber 53, and underflow chamber 54. Each cyclone separator 52 has an inner diameter of 30 mm, a height of 250 mm, is made of stainless steel, and has a polished inner wall. The separator has a tangential feed inlet 522, a top overflow port 521 connected to the overflow chamber 51 and the gas phase product collection unit 6, and a bottom underflow port 523 connected to the underflow chamber 54 and the liquid phase recycling unit 8. The overall processing capacity of the unit is designed to be 0.5 m³ / h.

[0092] An intermediate buffer tank 4 is installed between the photocatalytic hydrogen production module and the hydrogen purification module. The intermediate buffer tank 4 is a vertical cylindrical container made of stainless steel, designed with a pressure of 1.0 MPa, and its volume is designed to be 3 times the output volume of the hydrogen production module per minute.

[0093] The top of the intermediate buffer tank 4 is equipped with a pressure transmitter, a safety relief valve and a corrugated plate flame arrester; the middle of the tank is equipped with a magnetic float level gauge for continuous monitoring of the liquid level inside the tank; the top of the tank is equipped with a liquid outlet connected to a variable frequency delivery pump.

[0094] The target liquid level range is set to 30%-70% of the tank volume. When the liquid level is below 30%, the transfer pump speed is reduced to decrease the downstream extraction volume; when the liquid level is above 70%, the transfer pump speed is increased. The system issues an alarm signal when the liquid level exceeds the warning range of 20%-80%; if the liquid level remains abnormal (e.g., below 10% or above 90% for more than 30 seconds), the system automatically executes a shutdown protection procedure. The safety relief valve's discharge port is led to a safe outdoor area.

[0095] 3. Implementation process The method of this invention is implemented as follows: First, add to the wastewater The photocatalyst, prepared as a catalyst slurry with a solid content of 1.5 wt%, is stored in a feed tank and transported to the feed distribution unit 1 via a mixing pump 11. An external LED light source is turned on, and light energy is introduced into each swirling reactor 31 via a built-in light guide rod 21. The uniform radial light field distribution in the reaction zone is achieved through the light scattering microstructure on the surface of the light guide rod 21.

[0096] The feed flow rate was adjusted to ensure the catalyst slurry was uniformly injected into each cyclone reactor 31 at a tangential velocity of 2.0 m / s. The strong swirling flow field created by the tangential feed generated high shear force, driving the dynamic reconstruction of the catalyst particle microstructure. The average residence time of the catalyst slurry within the cyclone reactor 31 was controlled to be 150 s, ensuring continuous and stable system operation. Methanol in the wastewater, acting as a hole sacrificial agent, underwent a reforming reaction under the action of a photocatalyst, continuously generating hydrogen gas.

[0097] The gas-liquid mixture generated by the reaction flows out through the outlet of the cyclone reactor 31, is buffered by the intermediate buffer tank 4, and then transported to the feed buffer chamber 53 of the hydrogen extraction module, entering each cyclone separator 52 at a tangential flow velocity of 2.8 m / s. Inside the cyclone separator 52, the centrifugal force generated by the high-speed cyclone causes the gaseous hydrogen to rapidly gather towards the center and enter the gaseous product collection unit 6 from the top overflow port 521; the catalyst-rich liquid phase moves downward along the vessel wall and flows into the underflow chamber 54 from the bottom underflow port 523.

[0098] After separation, approximately 70% of the catalyst slurry is returned to the feed distribution unit 1 of the photocatalytic hydrogen production module via the circulation pipeline of the liquid phase recycling unit 8. There, it mixes with fresh wastewater and replenished catalyst before re-participating in the reaction. The remaining 30% is discharged through the drain outlet 7 to exit the system and enter the subsequent solid-liquid separation unit for catalyst recovery. Simultaneously, an equal amount of fresh catalyst is added to the system to maintain the activity and concentration balance of the catalyst within the reaction system. The system operates continuously for 72 hours.

[0099] Implementation Results: After the reaction operation stabilized, the light intensity distribution inside each cyclone reactor 31 was detected. The results are as follows: the light intensity at the inner wall of the reactor is 90 mW / cm², the light intensity at the center is 85 mW / cm², and the radial light intensity non-uniformity is less than 8%. This indicates that the coaxial setting of the built-in light guide rod 21 and the cyclone reactor 31, combined with the surface light scattering microstructure and density gradient design, has achieved a good uniform distribution of the light field.

[0100] Online gas chromatography analysis of the gaseous products revealed a hydrogen yield of 15.8 mmol / h (based on the total yield of 10 reactors), which is approximately 2.8 times higher than that of a traditional stirred reactor (with a hydrogen yield of approximately 5.6 mmol / h under the same illumination conditions and catalyst dosage). The collected hydrogen had a purity exceeding 99.0%.

[0101] The properties and parameters of the treated wastewater are shown in Table 2 below, with significant removal effects on COD and methanol content.

[0102]

[0103] During 72 hours of continuous system operation, the flow distribution deviation among the various cyclone reactors 31 was less than 5%, the hydrogen yield fluctuation range was within ±7%, and there was no obvious catalyst sedimentation or deactivation. The bottom outlets 523 of each cyclone separator 52 discharged smoothly without any bubble entrainment, and the gas-liquid separation efficiency remained stable. The COD and methanol content of the treated effluent were significantly reduced, achieving the dual objectives of wastewater purification and hydrogen recovery.

[0104] 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.

[0105] 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.

[0106] The above-described embodiments are merely illustrative 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 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 photocatalytic device for cyclone-enhanced hydrogen production and extraction in a two-stage tandem configuration, characterized in that, The photocatalytic device includes a photocyclone hydrogen production device and a cyclone hydrogen extraction device that are connected in series and physically separated along the material flow direction; The optical cyclone hydrogen production device includes: A swirl reaction unit includes multiple swirl reactors connected in parallel. The feed distribution unit has a tangential feed inlet and multiple discharge outlets, which are respectively connected to the inlet of each of the cyclone reactors and are used to distribute catalyst slurry to each of the cyclone reactors. The light source introduction unit includes an external light source and multiple built-in light guides. One end of each light guide is disposed inside the corresponding swirling reactor, and the other end is connected to the external light source. The hydrocyclone hydrogen extraction device includes: The hydrocyclone hydrogen extraction unit includes multiple hydrocyclone separators arranged in parallel in a circumferential array. Each hydrocyclone separator has a tangential feed inlet, a top overflow inlet, and a bottom underflow inlet. The tangential feed inlet is in fluid communication with the outlet of the hydrocyclone reactor. A gaseous product collection unit is connected to the top overflow port; The liquid phase recycling unit connects the bottom underflow port to the tangential feed port of the feed distribution unit, forming a circulation path for the catalyst slurry.

2. The photocatalytic device for cyclone-enhanced hydrogen production and extraction in a two-stage tandem configuration according to claim 1, characterized in that, An intermediate buffer tank is provided between the photocyclone hydrogen production device and the cyclone hydrogen extraction device. The inlet of the intermediate buffer tank is connected to the outlet of the cyclone reactor. The side or bottom outlet of the intermediate buffer tank is connected to the tangential feed port of the cyclone separator through a transfer pump. The intermediate buffer tank is equipped with a liquid level detection and control device, which is electrically connected to the transfer pump and is used to adjust the operating parameters of the transfer pump according to the liquid level in the tank.

3. The photocatalytic device for cyclone-enhanced hydrogen production and extraction in a two-stage tandem configuration according to claim 2, characterized in that, The feeding and distributing unit is a feeding tank, the bottom of which is connected to the tangential feeding port, and the periphery of which is connected to each of the discharge ports. The cyclone reaction unit includes a cyclone tank, and the cyclone hydrogen extraction unit includes a separation tank; The cyclone tank has multiple cyclone inlets on its periphery and a cyclone outlet at its top. The separation tank is formed with an overflow chamber, a feed buffer chamber, and an underflow chamber arranged sequentially from top to bottom and separated from each other. The cyclone inlet is connected to the corresponding outlet of the cyclone reactor, the cyclone outlet is connected to the feed buffer chamber through an intermediate buffer tank, the tangential feed inlet of the cyclone separator is connected to the feed buffer chamber, the overflow chamber is connected to the top overflow port of the cyclone separator and the gas phase product collection unit respectively; the underflow chamber is connected to the bottom underflow port of the cyclone separator and the liquid phase recycling unit respectively.

4. The photocatalytic device for cyclone-enhanced hydrogen production and extraction in a two-stage tandem configuration according to claim 3, characterized in that, The inlet of each of the cyclone reactors is connected to the corresponding outlet via a regulating valve.

5. The photocatalytic device for cyclone-enhanced hydrogen production and extraction in a two-stage tandem configuration according to claim 1, characterized in that, The built-in light guide rod has a light scattering microstructure at one end inside the swirling reactor; the light scattering microstructure is selected from at least one of surface roughening structure, microprism array structure, light scattering coating, and fiber grating bundle structure, so that the light intensity non-uniformity on the radial cross section of the swirling reactor is less than 10%.

6. A photocatalytic method for hydrogen production and extraction in a two-stage tandem process enhanced by cyclone flow, characterized in that, The apparatus of any one of claims 1 to 5 comprises: S100: External light source is introduced through the built-in light guide rod, and a uniform light field is formed on the radial section of the cyclone reactor; S200: The catalyst slurry is injected into the cyclone reactor of the photocyclone hydrogen production device to form a cyclone field, so that the catalyst particles dynamically update the surface active sites under the action of centrifugal force, and carry out photocatalytic hydrogen production reaction under the irradiation of an external light source to obtain a gas-liquid mixture. S300: The gas-liquid mixture is fed into the hydrocyclone separator of the hydrocyclone hydrogen extraction device for gas-liquid separation to obtain hydrogen products and a slurry rich in catalyst. S400: Collect the hydrogen products and return at least a portion of the catalyst-rich slurry to the feed distribution unit of the photocyclone hydrogen production device via the liquid phase recycling unit.

7. The photocatalytic method for cyclone-enhanced hydrogen production and extraction in a two-stage tandem process according to claim 6, characterized in that, In S200, the average residence time of the catalyst slurry in the cyclone reactor is 30s to 300s, and the solid content of the slurry is 0.1wt% to 5.0wt%.

8. The photocatalytic method for cyclone-enhanced hydrogen production and extraction in a two-stage tandem process according to claim 6, characterized in that, In the S400, 10% to 80% of the catalyst slurry after hydrogen extraction is returned to the feed distribution unit of the photocyclone hydrogen production unit, while another part of the slurry is discharged and fresh catalyst slurry is added to maintain the balance of catalyst activity and concentration.

9. The photocatalytic method for cyclone-enhanced hydrogen production and extraction in a two-stage tandem process according to claim 6, characterized in that, The external light source is sunlight or an artificial light source.

10. The photocatalytic method for cyclone-enhanced hydrogen production and extraction in a two-stage tandem process according to claim 6, characterized in that, The liquid medium used in the reaction is deionized water or wastewater containing biodegradable organic matter.

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