Plasma and metal catalysis integrated waste gas treatment equipment

Abstract

The invention relates to the technical field of environmental protection engineering and waste gas treatment, in particular to plasma and metal catalysis integrated waste gas treatment equipment which comprises a ventilation box and at least one plasma and metal catalysis module. The plasma synergistic metal catalysis module comprises a plasma discharge module and a metal catalysis net, the plasma discharge module and the metal catalysis net are vertically arranged in the ventilation box body in parallel, and the distance between the plasma discharge module and the metal catalysis net is 2-30 cm; plasma and ultraviolet light escaping from the plasma discharge module are utilized to perform photoelectric synergistic catalysis with the metal catalysis net, so that advantage complementation is realized, efficient mineralization of VOCs at normal temperature and normal pressure is realized, and a more efficient waste gas purification effect is achieved; the distance between the plasma discharge module and the metal catalysis net is controlled, so that a catalyst of the metal catalysis net can keep long-term stability in a high-concentration plasma environment, the adaptability is wider, and purification treatment of low-concentration and high-concentration organic waste gas is met.

Description

Technical Field

[0001] This invention relates to the fields of environmental engineering and waste gas treatment technology, specifically to an integrated waste gas treatment device using plasma-assisted metal catalysis. Background Technology

[0002] Existing industrial organic waste gas treatment solutions require activated carbon adsorption, followed by desorption via zeolite rotor heating after adsorption saturation, and then into a catalytic combustion tower (RCO) or ultra-high concentration plasma circulation treatment before being discharged into the atmosphere.

[0003] This solution requires complex processes, occupies a large area, consumes a lot of energy, and has high operating costs. Activated carbon, as a hazardous industrial product, not only places a significant economic burden on enterprises when used in large quantities, but also creates an environmental pollution burden. The catalytic combustion tower requires a large site, significant upfront investment, and high energy consumption during operation, resulting in persistently high operating costs.

[0004] Plasma generators ionize gases using a high-voltage electric field, producing high-energy electrons, ions, and free radicals. These particles collide with pollutant molecules, breaking their chemical bonds and oxidizing them into harmless substances (such as CO2 and H2O). This process can simultaneously treat complex mixed waste gases containing sulfur, chlorine, and benzene, and is particularly suitable for treating low-concentration, high-odor waste gases.

[0005] Plasma generators, due to their inherent limitations, have low energy utilization rates when treating organic waste gas. They require high power to generate ultra-high concentrations of plasma to degrade organic pollutants, necessitating the installation of catalytic devices at the tail end to meet emission standards. To improve purification efficiency, ultraviolet lamps are installed within the catalytic device to activate the catalyst. However, ultraviolet lamps are prone to generating heat and pose a risk of combustion and explosion. If the catalyst is filled into the plasma generator, its long-term stability is poor. Summary of the Invention

[0006] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide an integrated waste gas treatment device with plasma-coordinated metal catalysis.

[0007] The objective of this invention is achieved through the following technical solution: an integrated waste gas treatment device with plasma-coordinated metal catalysis, comprising a ventilation box and at least one set of plasma-coordinated metal catalysis modules housed within the ventilation box, wherein the air inlet of the ventilation box, the plasma-coordinated metal catalysis modules, and the air outlet of the ventilation box are sequentially connected; the plasma-coordinated metal catalysis module comprises a plasma discharge module and a metal catalytic mesh disposed downwind of the plasma discharge module, wherein the plasma discharge module and the metal catalytic mesh are arranged vertically and parallel within the ventilation box, and the distance between the plasma discharge module and the metal catalytic mesh is 2-30 cm.

[0008] Preferably, the plasma discharge module includes a DDBD dual-dielectric plasma discharge disk fixedly connected to the ventilation box.

[0009] Preferably, the power density of the DDBD dual-dielectric plasma discharge disk is 650-1000W, the required pulse frequency is 1-30KHz, and the required voltage is 12000V-25000V.

[0010] Preferably, the number of plasma-coordinated metal catalytic modules is 2-5, and the distance between adjacent plasma discharge modules and metal catalytic mesh is 3-25 cm.

[0011] Preferably, the metal catalytic mesh includes a mesh frame slidably connected to the ventilation box, a catalytic mesh plate fixedly connected to the inner side wall of the mesh frame, and a catalyst layer adhered to the surface of the catalytic mesh plate.

[0012] Preferably, the catalyst layer is at least one selected from titanium dioxide, carbon nitride, cadmium sulfide, manganese dioxide, zinc oxide, copper oxide, iron oxide, ferrous oxide, and aluminum oxide.

[0013] Preferably, the integrated waste gas treatment equipment further includes a pre-filtration system, which includes a spray filter and a dry filter, and the spray filter, the dry filter and the ventilation box are connected in sequence along the gas conveying direction.

[0014] Preferably, the integrated waste gas treatment equipment further includes a fan connected to the air outlet of the ventilation box, the fan being used to control the gas flow rate inside the ventilation box to be between 1-10 m / s.

[0015] The beneficial effects of this invention are as follows: The integrated waste gas treatment device of the present invention, which utilizes plasma-coordinated metal catalysis, employs a ventilation box and at least one set of plasma-coordinated metal catalysis modules housed within the ventilation box. The air inlet of the ventilation box, the plasma-coordinated metal catalysis modules, and the air outlet of the ventilation box are sequentially connected. The plasma-coordinated metal catalysis module includes a plasma discharge module and a metal catalytic mesh disposed downwind of the plasma discharge module. The plasma discharge module and the metal catalytic mesh are arranged vertically and parallel within the ventilation box, with a distance of 2-30 cm between them. On one hand, the plasma discharge module and the metal catalytic mesh have a dual function, utilizing the plasma and ultraviolet light emitted from the plasma discharge module to achieve photoelectric synergistic catalysis with the metal catalytic mesh, realizing mutually beneficial synergistic effects. Furthermore, the high-energy environment generated by plasma can activate the catalyst, forming highly active electron-hole pairs, enhancing its low-temperature activity and improving energy utilization efficiency. Simultaneously, it enhances the efficiency of free radical chain reactions, significantly increasing free radical yield and overall oxidizing power. This enables efficient decomposition of recalcitrant VOCs such as benzene and aldehydes, promotes the decomposition of ozone into atomic oxygen, inhibits the accumulation of byproducts, and achieves efficient mineralization of VOCs at room temperature and pressure. This results in more efficient waste gas purification without increasing energy consumption. On the other hand, controlling the spacing allows the catalyst in the metal catalytic mesh to maintain long-term stability in a high-concentration plasma environment. Moreover, the ultraviolet light generated by the plasma discharge module is cold light, avoiding the risk of combustion and explosion associated with traditional ultraviolet lamps, making it more adaptable and suitable for the purification of both low-concentration and high-concentration organic waste gases.

[0016] Compared to traditional industrial waste gas treatment processes and catalytic combustion towers (RCO), the integrated waste gas treatment equipment of this invention does not require additional activated carbon adsorption and zeolite rotor desorption processes, has low site requirements, and can achieve direct discharge of purified waste gas with low energy consumption, providing an optimized solution for waste gas treatment for more enterprises. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating Embodiment 1 of the present invention; The attached diagram is labeled as follows: 1. Ventilation box; 2. Plasma discharge module; 3. Metal catalytic mesh; 31. Mesh frame; 32. Catalytic mesh plate; 4. Spray filter; 5. Dry filter; 6. Fan. Detailed Implementation

[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0019] Example 1 like Figure 1As shown, an integrated waste gas treatment device using plasma-coordinated metal catalysis includes a ventilation box 1 and at least one set of plasma-coordinated metal catalysis modules housed within the ventilation box 1. The air inlet, the plasma-coordinated metal catalysis modules, and the air outlet of the ventilation box 1 are sequentially connected. The plasma-coordinated metal catalysis module includes a plasma discharge module 2 and a metal catalytic mesh 3 disposed downwind of the plasma discharge module 2. The plasma discharge module 2 and the metal catalytic mesh 3 are arranged vertically and parallel within the ventilation box 1, with a distance of 2-30 cm between them.

[0020] Furthermore, the plasma discharge module 2 includes a DDBD dual-dielectric plasma discharge disk fixedly connected to the ventilation box 1.

[0021] Furthermore, the DDBD dual-dielectric plasma discharge disk has a power density of 650-1000W, a required pulse frequency of 1-30KHz, and a required voltage of 12000V-25000V. In this embodiment, the DDBD dual-dielectric plasma discharge disk has a power density of 1000W, a required pulse frequency of 10kHz, and a required voltage of 15000V. The DDBD dual-dielectric plasma discharge disk generates low-temperature plasma with a plasma molar concentration of 10^24. During this process, gas molecules are ionized, forming active particles including high-energy electrons, ions, free radicals, and excited-state molecules. These active particles can collide with pollutant molecules in the exhaust gas, causing them to ionize, dissociate, and excite, thereby triggering a series of complex physical and chemical reactions. This transforms complex macromolecular pollutants into simple, safe small-molecule substances, or converts toxic and harmful substances into non-toxic, harmless, or low-toxic and low-harm substances. When excited-state molecules or ions transition from high-energy levels to low-energy levels, they release energy, a portion of which is radiated in the form of photons, accompanied by the generation of ultraviolet light. The plasma-generated high-energy environment of the metal catalytic network 3 promotes photoelectric synergistic catalysis, achieving complementary advantages. The high-energy environment of the plasma can activate the catalyst, forming highly active electron-hole pairs, enhancing its low-temperature activity and improving energy utilization efficiency. At the same time, it enhances the efficiency of free radical chain reaction, significantly increasing the free radical yield and greatly improving the overall oxidation performance. It achieves efficient decomposition of recalcitrant VOCs such as benzene and aldehydes, promotes the decomposition of ozone into atomic oxygen, inhibits the accumulation of by-products, and achieves efficient mineralization of VOCs at room temperature and pressure. Without increasing energy consumption, it achieves a more efficient waste gas purification effect. On the other hand, controlling the spacing is beneficial for the catalyst of the metal catalytic network 3 to maintain long-term stability in a high-concentration plasma environment. Moreover, the ultraviolet light generated by the plasma discharge module 2 is cold light, avoiding the risk of combustion and explosion associated with traditional ultraviolet lamps, making it more adaptable and meeting the purification treatment needs of both low-concentration and high-concentration organic waste gases.

[0022] Furthermore, the number of plasma-coordinated metal catalytic modules is 2-5 sets, and the distance between adjacent plasma discharge modules 2 and metal catalytic mesh 3 is 3-25 cm. In this embodiment, the number of plasma-coordinated metal catalytic modules is 3 sets, and the distance between adjacent plasma discharge modules 2 and metal catalytic mesh 3 is 10 cm.

[0023] Furthermore, the metal catalytic mesh 3 includes a mesh frame 31 slidably connected to the ventilation box 1, a catalytic mesh plate 32 fixedly connected to the inner side wall of the mesh frame 31, and a catalyst layer adhered to the surface of the catalytic mesh plate 32.

[0024] Furthermore, the catalyst layer is at least one of anatase titanium dioxide, carbon nitride, cadmium sulfide, manganese dioxide, zinc oxide, copper oxide, iron oxide, ferrous oxide, and aluminum oxide. Furthermore, the catalyst layer is composed of anatase titanium dioxide, carbon nitride, manganese dioxide, iron oxide, and ferrous oxide in a weight ratio of 3-5:1-2:1:1-2:1-2. In this embodiment, the catalyst layer is composed of anatase titanium dioxide, carbon nitride, manganese dioxide, iron oxide, and ferrous oxide in a weight ratio of 4:2:1:1:1. Anatase titanium dioxide has strong photochemical activity, can absorb light energy, generate electron-hole pairs, and thus initiate redox reactions. Carbon nitride has good light absorption performance and chemical stability, and can form heterojunctions with titanium dioxide, promoting the separation and transport of photogenerated charge carriers, thereby improving photoelectrocatalytic efficiency. Manganese dioxide, iron oxide, and ferrous oxide provide abundant redox active sites, which synergistically participate in photoelectrocatalytic reactions with the active sites of titanium dioxide and carbon nitride, achieving a more efficient waste gas purification effect.

[0025] Furthermore, the integrated waste gas treatment equipment also includes a pre-filtration system, which comprises a spray filter 4 and a dry filter 5. The spray filter 4, dry filter 5, and ventilation housing 1 are connected sequentially along the gas conveying direction. The spray filter 4 sprays water mist into the waste gas, utilizing the principle of heat absorption through water evaporation to effectively reduce the temperature of the waste gas. Simultaneously, the water mist collides and agglomerates with particulate matter in the waste gas, forming larger particles that subsequently settle down due to gravity, thereby removing particulate matter from the waste gas. The dry filter 5 effectively removes particulate matter from the waste gas through the interception and adsorption of filter media, while simultaneously reducing the relative humidity of the waste gas to below 80%.

[0026] Furthermore, the integrated waste gas treatment equipment also includes a fan 6 connected to the air outlet of the ventilation box 1, the fan 6 being used to control the gas flow velocity within the ventilation box 1 to be between 1 and 10 m / s. In this embodiment, the fan 6 is used to control the gas flow velocity within the ventilation box 1 to be 5 m / s.

[0027] Example 2 The difference between this embodiment and Embodiment 1 is that: The DDBD dual-dielectric plasma discharge disk has a power density of 650W, a required pulse frequency of 10KHz, and a required voltage of 12000V.

[0028] The number of plasma-coordinated metal catalytic modules is 4, and the distance between adjacent plasma discharge modules and metal catalytic mesh is 3 cm.

[0029] Example 3 The difference between this embodiment and Embodiment 1 is that: The DDBD dual-dielectric plasma discharge disk has a power density of 1000W, a required pulse frequency of 20KHz, and a required voltage of 25000V.

[0030] The number of plasma-coordinated metal catalytic modules is 2 sets, and the distance between adjacent plasma discharge modules and metal catalytic mesh is 20cm.

[0031] Comparative Example 1 The difference between this comparative example and Example 1 is as follows: A plasma purification waste gas treatment device includes a ventilation box and a plasma discharge module housed in the ventilation box. The air inlet of the ventilation box, the plasma discharge module and the air outlet of the ventilation box are connected in sequence. The number of plasma discharge modules is 6, and the 6 plasma discharge modules are arranged vertically and parallel in the ventilation box. The distance between two adjacent plasma discharge modules is 10cm.

[0032] The plasma discharge module includes a DDBD dual-dielectric plasma discharge disk fixedly connected to the ventilation box.

[0033] The DDBD dual-dielectric plasma discharge disk has a power density of 1000W, a required pulse frequency of 10KHz, and a required voltage of 15000V.

[0034] The integrated waste gas treatment equipment also includes a pre-filtration system, which includes a spray filter and a dry filter. The spray filter, the dry filter, and the ventilation box are connected in sequence along the gas conveying direction.

[0035] The integrated waste gas treatment equipment also includes a fan connected to the air outlet of the ventilation box, which is used to control the gas flow rate inside the ventilation box to 5m / s.

[0036] Comparative Example 2 The difference between this comparative example and Example 1 is as follows: A metal catalytic purification waste gas treatment device includes a ventilation box and a metal catalytic mesh housed in the ventilation box. The air inlet of the ventilation box, the metal catalytic mesh and the air outlet of the ventilation box are connected in sequence. There are 6 metal catalytic meshes, which are arranged vertically and parallel in the ventilation box, and the distance between two adjacent metal catalytic meshes is 10cm.

[0037] The metal catalytic mesh includes a mesh frame that is slidably connected to the ventilation box, a catalytic mesh plate that is fixedly connected to the inner side wall of the mesh frame, and a catalyst layer that is adhered to the surface of the catalytic mesh plate.

[0038] The catalyst layer is composed of anatase titanium dioxide, carbon nitride, manganese dioxide, iron oxide and ferrous oxide in a weight ratio of 4:2:1:1:1.

[0039] The integrated waste gas treatment equipment also includes a pre-filtration system, which includes a spray filter and a dry filter. The spray filter, the dry filter, and the ventilation box are connected in sequence along the gas conveying direction.

[0040] The integrated waste gas treatment equipment also includes a fan connected to the air outlet of the ventilation box, which is used to control the gas flow rate inside the ventilation box to 5m / s.

[0041] Comparative Example 3 The difference between this comparative example and Example 1 is as follows: The catalyst layer is composed of cobalt tetroxide, palladium alumina, manganese dioxide, iron oxide and ferrous oxide in a weight ratio of 4:2:1:1:1.

[0042] Comparative Example 4 The difference between this comparative example and Example 1 is as follows: The distance between adjacent plasma discharge modules and metal catalytic mesh is 0.8 cm.

[0043] Comparative Example 5 The difference between this comparative example and Example 1 is as follows: The distance between adjacent plasma discharge modules and metal catalytic mesh is 35cm.

[0044] Performance testing: Take the waste gas treatment equipment of Example 1 and Comparative Examples 1-5, wherein, The plasma discharge modules used are all model SBS-100-1000W-2, which consists of a high-voltage AC power supply and a DDBD dual-dielectric plasma discharge disk. The technical parameters of each component are as follows: The technical parameters of the DDBD dual-dielectric plasma discharge disk are shown in Table 1 below:

[0045] The technical parameters of the high-voltage AC power supply are shown in Table 2 below:

[0046] I. Using the waste gas treatment equipment of Example 1 and Comparative Examples 1-5, a circulating treatment test was conducted, and the test results are shown in Table 3 below:

[0047] II. Using the waste gas treatment equipment of Example 1 and Comparative Examples 1-5, direct emission treatment tests were conducted, and the test results are shown in Table 4 below:

[0048] III. Using the waste gas treatment equipment of Example 1 and Comparative Examples 1-5, and simultaneously running it in an atmospheric environment for 1000 hours, a cycle treatment test was conducted again. The test results are shown in Table 5 below:

[0049] As shown in Tables 3 to 5 above, the waste gas treatment equipment of the present invention utilizes the plasma and ultraviolet light emitted from the plasma discharge module and the metal catalytic mesh for photoelectric synergistic catalysis, achieving complementary advantages and realizing efficient mineralization of VOCs at normal temperature and pressure, resulting in a more efficient waste gas purification effect. Controlling the distance between the plasma discharge module and the metal catalytic mesh helps the catalyst of the metal catalytic mesh to maintain long-term stability in a high-concentration plasma environment, making it more adaptable and meeting the purification treatment requirements of both low-concentration and high-concentration organic waste gases.

[0050] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. An integrated waste gas treatment device using plasma-assisted metal catalysis, characterized in that: The device includes a ventilation box and at least one set of plasma-coordinated metal catalytic modules housed within the ventilation box. The air inlet of the ventilation box, the plasma-coordinated metal catalytic modules, and the air outlet of the ventilation box are connected in sequence. The plasma-coordinated metal catalytic module includes a plasma discharge module and a metal catalytic mesh disposed downwind of the plasma discharge module. The plasma discharge module and the metal catalytic mesh are arranged vertically and parallel within the ventilation box, with a distance of 2-30 cm between them.

2. The integrated waste gas treatment equipment with plasma-assisted metal catalysis according to claim 1, characterized in that: The plasma discharge module includes a DDBD dual-dielectric plasma discharge disk fixedly connected to the ventilation box.

3. The integrated waste gas treatment equipment with plasma-assisted metal catalysis according to claim 2, characterized in that: The DDBD dual-dielectric plasma discharge disk has a power density of 650-1000W, a required pulse frequency of 1-30KHz, and a required voltage of 12000V-25000V.

4. The integrated waste gas treatment equipment with plasma-assisted metal catalysis according to claim 1, characterized in that: The number of plasma-coordinated metal catalytic modules is 2-5 sets, and the distance between adjacent plasma discharge modules and metal catalytic mesh is 3-25cm.

5. The integrated waste gas treatment equipment with plasma-assisted metal catalysis according to claim 1, characterized in that: The metal catalytic mesh includes a mesh frame that is slidably connected to the ventilation box, a catalytic mesh plate that is fixedly connected to the inner side wall of the mesh frame, and a catalyst layer that is adhered to the surface of the catalytic mesh plate.

6. The integrated waste gas treatment device with plasma-assisted metal catalysis according to claim 5, characterized in that: The catalyst layer is at least one of titanium dioxide, carbon nitride, cadmium sulfide, manganese dioxide, zinc oxide, copper oxide, iron oxide, ferrous oxide, and aluminum oxide.

7. The integrated waste gas treatment equipment with plasma-assisted metal catalysis according to claim 1, characterized in that: The integrated waste gas treatment equipment also includes a pre-filtration system, which includes a spray filter and a dry filter. The spray filter, the dry filter, and the ventilation box are connected in sequence along the gas conveying direction.

8. The integrated waste gas treatment equipment with plasma-assisted metal catalysis according to claim 1, characterized in that: The integrated waste gas treatment equipment also includes a fan connected to the air outlet of the ventilation box, which is used to control the gas flow rate inside the ventilation box to be between 1-10 m / s.

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