Photo-oxidation reactor suitable for processing large-flux organic gases

Abstract

This invention proposes a photo-oxidation reactor suitable for treating high-throughput organic gases, comprising a reactor shell; an ultraviolet (UV) lamp irradiation zone located at the inlet of the reactor shell, the UV lamp irradiation zone being equipped with a UV lamp assembly capable of emitting UV light; and an oxidation reaction zone located in the middle of the reactor shell, where the organic gases entering the reactor shell are irradiated by UV light and undergo oxidative degradation reactions. This invention achieves uniform UV light intensity distribution, reduces the reactor space velocity, and achieves efficient removal of organic gases through multi-stage modular gradation.

Description

Technical Field

[0001] This invention relates to a photo-oxidation reactor suitable for treating large-flux organic gases, belonging to the field of volatile organic compound (VOC) treatment. Background Technology

[0002] With rapid economic and social development, environmental issues have increasingly become a major contradiction affecting people's aspirations for a better life. Many countries and governments have recognized the seriousness of this problem and have promulgated a series of governance measures. Air pollution is one of the most acute environmental issues at present. In 2018, my country issued the "Three-Year Action Plan for Winning the Battle Against Air Pollution" to address the air pollution problems currently facing the country. The emission of volatile organic compounds (VOCs) is one of the important sources of air pollution, including organized and unorganized emissions from refining and chemical enterprises, as well as emissions from painting workshops in small and medium-sized enterprises.

[0003] Methods for treating volatile organic compounds (VOCs) are mainly divided into two categories: recovery methods and destruction methods. Recovery methods are primarily used for treating high-concentration, high-value VOC emissions, while destruction methods are suitable for treating low-concentration VOC emissions. Major destruction methods include regenerative thermal oxidizers (RTO), catalytic oxidation (RCO), biodegradation, photocatalytic oxidation, and advanced gas-phase oxidation. If the VOC concentration is low, for RTO, the heat generated from burning the VOCs is insufficient to maintain reactor operation, requiring additional gas combustion support; for catalytic oxidation, additional heating is needed to maintain the reaction temperature of the catalytic bed. Biodegradation methods are also unsuitable for treating large volumes of industrial waste gas.

[0004] Based on the above analysis, for gases with large flow rates and low VOC concentrations, VOC treatment methods such as RTO and RCO incur significant additional operating costs. If the flow rate is too high, additional treatment modules are required, further increasing investment costs. Advanced gas-phase oxidation (ACO) is a relatively new method that uses stronger oxidants, such as hydroxyl radicals and ozone, to replace oxygen, thereby achieving efficient VOC treatment. Currently, hydroxyl radical generation methods rely on ultraviolet light and the interaction of ozone and water vapor. Since hydroxyl radicals have a limited lifespan, the reactor is crucial for the oxidation of VOCs by hydroxyl radicals. Summary of the Invention

[0005] To address the aforementioned technical problems in the existing technology, this invention proposes a photo-oxidation reactor suitable for processing large-flux organic gases, achieving uniform distribution of ultraviolet light intensity, reducing the space velocity of the reactor, and achieving efficient removal of organic gases through multi-stage modular gradation.

[0006] This invention proposes a photo-oxidation reactor suitable for treating high-flux organic gases, comprising:

[0007] Reactor shell;

[0008] An ultraviolet (UV) lamp irradiation zone is located at the inlet of the reactor shell, and the UV lamp irradiation zone is equipped with a UV lamp assembly capable of emitting UV light; and

[0009] An oxidation reaction zone is located in the middle of the reactor shell. Organic gases entering the reactor shell are irradiated with ultraviolet light in the oxidation reaction zone and undergo an oxidative degradation reaction.

[0010] A further improvement of the present invention is that a highly reflective liner is provided on the inner wall of the reactor shell.

[0011] A further improvement of the present invention is that the reactor shell is provided with multiple inlet pipes, and each inlet pipe is provided with an ultraviolet lamp irradiation zone;

[0012] A further improvement of the present invention is that the inlet pipe is a cylindrical or cuboid cylinder, the inlet pipe is inclinedly arranged at the lower part of the reactor shell, and the included angle between two connected inlet pipes is less than 150°.

[0013] A further improvement of the present invention is that the inlet pipe is frustoconical or pyramidal, and the central axis of the inlet pipe is radially disposed at the lower part of the reactor shell.

[0014] A further improvement of the present invention is that the inlet of the reactor shell is provided with a first ultraviolet light induction device, which is a frustum-shaped or pyramid-shaped reflector that reflects ultraviolet light into the oxidation reaction zone.

[0015] A further improvement of the present invention is that a second ultraviolet light induction device is provided at the outlet of the reactor shell. The second ultraviolet light induction device is a frustum-shaped or pyramidal reflector that reflects ultraviolet light into the oxidation reaction zone.

[0016] A further improvement of the present invention is that the ultraviolet lamp group includes several groups of ultraviolet lamps, and multiple ultraviolet lamps in each group are arranged in parallel, and the ultraviolet lamp group is parallel or perpendicular to the airflow direction.

[0017] A further improvement of the present invention is that an air stirrer is provided in the oxidation reaction zone.

[0018] A further improvement of the present invention is that the inlet of the reactor shell is provided with a flange.

[0019] Compared with the prior art, the advantages of the present invention are as follows:

[0020] The photo-oxidation reactor described in this invention is suitable for treating high-throughput organic gases. It primarily relies on the generation of active components such as hydroxyl radicals from ozone and water vapor under ultraviolet light, which then oxidize and degrade the organic gases. The intensity of ultraviolet light affects the generation rate of hydroxyl radicals, requiring a high degree of control over the light intensity distribution within the reactor to enhance the effective residence time of organic gases. Therefore, a certain space velocity is required within the reactor. To address these issues, this invention optimizes the reactor structure to achieve a uniform distribution of ultraviolet light intensity, reducing the reactor's space velocity. Furthermore, through multi-stage modular gradation, it achieves highly efficient removal of organic gases. This technology facilitates the promotion and application of advanced gas-phase oxidation technology in industrial organic gas treatment.

[0021] This invention places the ultraviolet lamp assembly at the gas inlet, and the ultraviolet lamp assembly adopts an easy-to-disassemble design for convenient daily maintenance. The multi-inlet mode can significantly reduce the inlet flow rate, thereby reducing the space velocity in the reactor and increasing the residence time in the reactor, thus increasing the efficiency of VOCs oxidation. On the other hand, this reactor can be used in situations with fluctuating flow rates. By controlling the flow rate, the number of inlets that can be opened can be selected, thereby greatly reducing operating costs.

[0022] The present invention employs a light guiding device at the inlet or outlet to increase the uniformity of light intensity inside the reactor and reduce ultraviolet leakage. Attached Figure Description

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0024] Figure 1 The diagram shown is a schematic representation of a photo-oxidation reactor suitable for processing large-flux organic gases according to an embodiment of the present invention, showing the reactor shell with multiple cylindrical or rectangular inlet pipes.

[0025] Figure 2 The diagram shown is a schematic representation of a photo-oxidation reactor suitable for processing large-flux organic gases according to an embodiment of the present invention, showing the reactor shell with multiple frustum-shaped or pyramidal-shaped inlet pipes.

[0026] Figure 3 The diagram shown is a schematic representation of a photo-oxidation reactor suitable for processing large-flux organic gases according to an embodiment of the present invention, showing a single-inlet cuboid reactor shell.

[0027] Figure 4 The diagram shown is a schematic representation of a photo-oxidation reactor suitable for processing large-flux organic gases according to an embodiment of the present invention, showing a single-inlet cylindrical reactor shell;

[0028] Figure 5The diagram shown is a schematic representation of the inlet pipe according to an embodiment of the present invention.

[0029] Figure 6 The diagram shown is a structural schematic of an ultraviolet lamp assembly according to an embodiment of the present invention;

[0030] Figure 7 The diagram shown is a schematic diagram of the connection of an oxidation reaction apparatus according to an embodiment of the present invention.

[0031] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0032] The meanings of the reference numerals in the attached figures are as follows:

[0033] 1. Reactor shell, 2. Reactor inlet, 3. Reactor outlet, 4. Ultraviolet lamp irradiation zone, 5. First ultraviolet light induction device, 6. Second ultraviolet light induction device, 7. Oxidation reaction zone, 8. High reflectivity liner, 9. Ultraviolet lamp assembly, 10. Inlet pipe. Detailed Implementation

[0034] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0035] Figure 1 The diagram schematically illustrates a photo-oxidation reactor according to the present invention, suitable for treating high-throughput organic gases, comprising a reactor shell 1; an inlet 2 of the reactor shell is provided with an ultraviolet lamp irradiation zone 4, the ultraviolet lamp irradiation zone 4 being provided with an ultraviolet lamp assembly capable of emitting ultraviolet light. An oxidation reaction zone 7 is provided in the middle of the reactor shell 1, where the organic gases entering the reactor shell 1 are irradiated with ultraviolet light and undergo an oxidative degradation reaction.

[0036] A particulate eliminator and a microwave thermal coupling purifier are connected to outlet 3 of reactor shell 1. Organic gas enters reactor shell 1 from inlet 2, first passing through ultraviolet lamp irradiation zone 4 before entering oxidation reaction zone 7. Under ultraviolet irradiation, highly reactive components with high oxidizing power, such as hydroxyl radicals, are generated. These hydroxyl radicals react with organic gas molecules, degrading most of them into CO2 and H2O. Some organic gas molecules form oligomers, or nanoparticles, under the action of hydroxyl radicals. The unreacted ozone in the catalytic bed is then treated by the particulate eliminator and microwave thermal coupling purifier, ensuring the treated gas meets emission standards.

[0037] In one embodiment, a high-reflectivity liner 8 is provided on the inner wall of the reactor shell 1. The high-reflectivity liner 8 is capable of reflecting ultraviolet light. Preferably, in this embodiment, high-reflectivity mirror aluminum is used, with a reflectivity of 98%. Due to the reflective effect of the mirror, a high intensity of ultraviolet light can be maintained even in the oxidation reaction zone 7.

[0038] In one embodiment, such as Figure 2 As shown, the reactor shell 1 is provided with multiple inlet pipes 10, and each inlet pipe 10 is provided with an ultraviolet lamp irradiation zone 4.

[0039] Preferably, the inlet pipe 10 has a cylindrical or cuboid structure. For a cuboid inlet pipe 10, the angle between one inlet pipe 10 and a connected inlet pipe 10 is <150°. For a cylindrical inlet pipe 10, the angle between the tangents at the confluence point of two circular pipes is <150°. By providing multiple inlet pipes 10 while maintaining the original flow rate, the gas velocity can be reduced, allowing the gas to remain in the reactor shell 1 for a longer time, thus enabling the gas to react fully. In this embodiment, the cylindrical shape can be a straight cylindrical cavity or an arc-shaped cylindrical cavity, and its cross-section can be circular or elliptical.

[0040] In one embodiment, such as Figure 3 As shown, multiple inlet pipes 10 are provided on both sides of the reactor shell 1, and each inlet pipe 10 is provided with an ultraviolet lamp irradiation zone 4. The inlet pipe 10 is a truncated cone or frustum-shaped cylindrical structure, wherein the central axis of the truncated cone is radially arranged at the lower part of the reactor shell 1.

[0041] The reflective surface of the truncated cone or pyramidal pipe inlet 2 allows more light to illuminate the oxidation reaction zone 7. At the same time, multiple inlets 2 can reduce the gas flow rate, allowing the gas to remain in the reactor shell 1 for a longer time, thus enabling the gas to react fully.

[0042] In one embodiment, such as Figure 5 As shown, the inlet 2 of the reactor shell is provided with a first ultraviolet light induction device 5, which is a frustum-shaped or pyramid-shaped reflector that reflects ultraviolet light into the oxidation reaction zone 7.

[0043] In one embodiment, the outlet 3 of the reactor shell 1 is provided with a second ultraviolet light inducing device 6. The second ultraviolet light inducing device 6 is a frustum-shaped or pyramidal reflector that reflects ultraviolet light onto the oxidation reaction zone 7. By providing the first ultraviolet light inducing device 5 and the second ultraviolet light inducing device 6, the intensity of ultraviolet light inside the reactor shell 1 is enhanced and the loss of ultraviolet light is reduced.

[0044] In one embodiment, such as Figure 6As shown, the ultraviolet lamp assembly includes several groups of ultraviolet lamps, and multiple ultraviolet lamps in each group are arranged in parallel. Each group of ultraviolet lamps can be arranged side by side horizontally or longitudinally back and forth, and the ultraviolet lamps in each group can be parallel to or perpendicular to the airflow direction.

[0045] In one embodiment, an air stirrer is provided in the oxidation reaction zone 7. After the organic gas enters the reaction zone, it is stirred and rotated by the air stirrer. During the rotation, the collision between the active components and volatile organic compounds is increased, thereby increasing the reaction rate.

[0046] In a preferred embodiment, the reactor inlet 2 is provided with a flange. This allows for quick disassembly, removal, or installation of the ultraviolet lamp, facilitating disassembly, assembly, and maintenance.

[0047] In this embodiment, as Figure 7 As shown, a particulate eliminator and a microwave thermal coupling purifier are connected to outlet 3 of reactor shell 1. The included angle of outlet 3 of the photoreactor has a certain mathematical relationship with the included angle between the pipes; the included angle at outlet 3 is equal to half the included angle between the pipes. The photoreactor also includes flame arresters at inlet 2 and outlet 3 to prevent chain explosions. The particulate eliminator can use a nanofilter or an electrostatic precipitator for particulate removal. The microwave thermal coupling purifier uses microwaves to heat the catalytic bed to further eliminate unreacted organic gases and excess ozone, ensuring that the gas emitted from outlet 3 meets emission standards.

[0048] Example 1

[0049] This implementation example Figure 1 As shown, a photo-oxidation reactor suitable for processing large-flux organic gases includes a reactor shell 1 with two inlet pipes 10, each inlet pipe 10 having a reactor inlet 2, and each reactor inlet 2 having an ultraviolet lamp irradiation zone 4. The ultraviolet lamp irradiation zone 4 contains two groups of ultraviolet lamps 9, each group containing five ultraviolet lamps arranged side-by-side. The number and power of the ultraviolet lamps depend on the size and processing capacity of the reactor and can be adjusted as needed. In this embodiment, the ultraviolet lamps are oriented parallel to the gas flow direction.

[0050] The high-reflectivity material is high-reflectivity mirror aluminum with a reflectivity of 98%. Due to the reflective effect of the mirror, a high intensity of ultraviolet light can be maintained even in the oxidation reaction zone 7. In this embodiment, the inlet 2 and outlet 3 of the reactor shell are equipped with a first ultraviolet light induction device 5 and a second ultraviolet light induction device 6, which adopt a narrowing method. The narrowing angle α is preferably 60°, and the angle of the inlet 2 is the same as that of the outlet 3.

[0051] The included angle b between the two inlet pipes 10 is preferably 120°. The ultraviolet light that is vertically irradiated on the wall of the inlet 2 by the ultraviolet lamp can be reflected into the oxidation reaction zone 7, thereby increasing the ultraviolet irradiation intensity of the oxidation reaction zone 7. The ultraviolet light passes through the oxidation reaction zone 7 and then through the ultraviolet light induction device at the outlet 3, and returns to the oxidation reaction zone 7. The purpose of this is to reflect the ultraviolet light into the reactor and reduce the leakage of ultraviolet light.

[0052] The structure of this embodiment has two effects. On the one hand, the intensity of ultraviolet light in the reactive oxidation reaction zone 7 will increase, which will increase the intensity and duration of ultraviolet irradiation of the mixed gas, thereby increasing the amount and efficiency of hydroxyl radical production. On the other hand, the amount of ultraviolet light leakage will be reduced, increasing the energy utilization efficiency of the device and reducing operating costs over long periods of operation.

[0053] In this embodiment, the reactor has a symmetrical structure on both the left and right sides. The three-dimensional structure diagram on the left side is shown below. Figure 3 As shown, the reactor inlet 2 has a frustum structure, and the ultraviolet lamp group is set on one side of the gas inlet 2, followed by the cuboid oxidation reaction zone 7.

[0054] A gas mixer is installed in oxidation reaction zone 7 to accelerate gas mixing, thereby increasing the collision probability between active components such as hydroxyl radicals and organic gases, and improving the reactor's efficiency in degrading organic gases. The gas mixer is also made of high-reflectivity aluminum material with a reflectivity of 98%.

[0055] This invention employs a novel ultraviolet (UV) irradiation oxidation method for treating organic gases. It utilizes UV light to irradiate a mixture of ozone, water vapor, and organic gases. Under UV irradiation, the ozone and water vapor generate oxidizing components with high oxidizing power, primarily hydroxyl radicals, thereby rapidly degrading the organic gases. In this embodiment, the gas enters the reactor through inlet 2 of the reactor shell, first passing through the UV irradiation zone. After UV irradiation, highly reactive components with high oxidizing power, such as hydroxyl radicals, are generated. These hydroxyl radicals react with organic gas molecules, degrading most of them into CO2 and H2O. Some organic gas molecules form oligomers, or nanoparticles, under the action of the hydroxyl radicals. A dust collector and a catalytic bed for treating unreacted ozone are installed in the subsequent equipment of the reactor, ensuring that the treated gas meets emission standards.

[0056] Example 2

[0057] This implementation example Figure 2As shown, the main structure is similar to that of Embodiment 1, except that two inlet pipes 10 are provided at the inlet 2 of the reactor shell, and each inlet pipe 10 is provided with an ultraviolet lamp irradiation zone 4. The inlet pipe 10 is a truncated cone or frustum-shaped cylindrical structure, wherein the central axis of the truncated cone is arranged radially at the lower part of the reactor shell 1.

[0058] In this embodiment, the gas is split into two streams. The main irradiation area of ​​the ultraviolet light is the Y-shaped bifurcation reaction oxidation region of the ultraviolet lamp, where the gas is mainly oxidized and degraded before merging again. In this embodiment, the interior of the reactor shell 1 is lined with highly reflective mirror aluminum with a reflectivity of 98%.

[0059] In this embodiment, the two ultraviolet lamps are located inside the same cavity. In addition, an optimized structural design is provided on both sides of the device to enhance the reflectivity of ultraviolet light inside the cavity, so that the intensity of ultraviolet light is evenly distributed inside the reactor.

[0060] In oxidation reaction zone 7, a gas mixer is installed to mix the two gas paths after ultraviolet irradiation, accelerate the turbulence of the airflow, thereby accelerating the collision between hydroxyl radicals and organic gases and increasing the efficiency of the reactor in degrading organic gases.

[0061] Example 3

[0062] This implementation example Figure 3 As shown, the reactor shell 1 is a cylindrical or polygonal cylindrical structure, with an inlet 2 and an outlet 3. A first ultraviolet light induction device 5 is provided on the inlet 2 side, and a second ultraviolet light induction device 6 is provided on the outlet 3 side. The constriction is used to guide the ultraviolet light and ensure the intensity of the ultraviolet light in the entire reactor, thereby improving the efficiency of generating active oxidizing components and thus improving the efficiency of degrading organic gases.

[0063] In this embodiment, the inlet 2 adopts a frustum structure, the oxidation reaction zone 7 is a cuboid structure, and a gas mixer is installed inside the cuboid.

[0064] Example 4

[0065] This implementation example Figure 3 As shown, in this embodiment, the reactor shell has a single outlet 3 at inlet 2, and the remaining inner walls are made of high-reflectivity aluminum material with a reflectivity of 98%. A first ultraviolet light induction device 5 is installed on the inlet 2 side, and a second ultraviolet light induction device 6 is installed on the outlet 3 side. These devices employ a constricted design to guide ultraviolet light, ensuring its intensity throughout the reactor and thus improving the efficiency of generating oxidizing active components, thereby increasing the efficiency of degrading organic gases. In this embodiment, inlet 2 uses a frustum structure, and the oxidation reaction zone 7 is a cuboid structure with a gas mixer installed inside.

[0066] Example 5

[0067] This implementation example Figure 4 As shown, the reactor shell inlet 2 has a frustum structure. An ultraviolet lamp assembly is positioned to one side of the gas inlet 2, followed by a cylindrical oxidation reaction zone 7. The reactor interior, like in other embodiments, is equipped with a highly reflective material with a reflectivity of 98%. The frustum structure at the reactor inlet 2, similar to a truncated pyramid structure, allows ultraviolet light to be directed into the reactor interior, enhancing the light intensity in the oxidation reaction zone 7. The cylindrical structure of the reactor's oxidation zone further enhances the reflection of ultraviolet light within the cavity. Increased ultraviolet light intensity increases the content of hydroxyl radicals, an oxidizing active factor, thereby increasing the degradation rate of organic gases.

[0068] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and / or modifications falling within the scope of the invention, and all changes and / or modifications made according to embodiments of the invention should be covered within the protection scope of the invention.

Claims

1. A photo-oxidation reactor suitable for treating large-flux organic gases, characterized in that, include: Reactor shell (1); An ultraviolet lamp irradiation area (4) is set at the inlet (2) of the reactor shell, and the ultraviolet lamp irradiation area (4) is equipped with an ultraviolet lamp group capable of emitting ultraviolet light; as well as An oxidation reaction zone (7) is set in the middle of the reactor shell (1). Organic gases entering the reactor shell (1) are irradiated by ultraviolet light in the oxidation reaction zone (7) and undergo an oxidative degradation reaction. The inner wall of the reactor shell (1) is provided with a high-reflectivity liner (8). Due to the reflection effect of the mirror, a high ultraviolet light intensity can be maintained in the oxidation reaction zone (7). The inlet (2) of the reactor shell is provided with a first ultraviolet light induction device (5), which is a frustum-shaped or pyramid-shaped reflector that reflects ultraviolet light into the oxidation reaction zone (7). The reactor shell (1) is provided with multiple inlet pipes (10), and each inlet pipe (10) is provided with an ultraviolet lamp irradiation area (4).

2. The photo-oxidation reactor for treating high-flux organic gases according to claim 1, characterized in that, The inlet pipe (10) is a cylindrical or rectangular tube. The inlet pipe (10) is inclinedly arranged at the lower part of the reactor shell (1), and the included angle between two connected inlet pipes (10) is less than 150°.

3. The photo-oxidation reactor for treating high-throughput organic gases according to claim 2, characterized in that, The inlet pipe (10) is frustum-shaped or pyramidal-shaped, and the central axis of the inlet pipe (10) is radially arranged at the lower part of the reactor shell (1).

4. The photo-oxidation reactor for treating high-flux organic gases according to claim 3, characterized in that, The outlet (3) of the reactor shell (1) is provided with a second ultraviolet light induction device (6), which is a frustum-shaped or pyramid-shaped reflector that reflects ultraviolet light into the oxidation reaction zone (7).

5. The photo-oxidation reactor for treating high-flux organic gases according to claim 4, characterized in that, The ultraviolet lamp group includes several groups of ultraviolet lamps, and multiple ultraviolet lamps in each group are arranged in parallel. The ultraviolet lamp group is parallel or perpendicular to the airflow direction.

6. The photo-oxidation reactor for treating high-flux organic gases according to claim 5, characterized in that, An air stirrer is installed in the oxidation reaction zone (7).

7. The photo-oxidation reactor for treating high-flux organic gases according to claim 6, characterized in that, The inlet (2) of the reactor shell is provided with a flange.

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