Chemical methanation tail gas ozone degradation purification device

Abstract

The present application relates to a kind of chemical methanation tail gas ozone degradation purification device, belong to purification device technical field.The device rack, pre-depth purification unit, first mixed constant temperature container, accurate humidifying unit and second ultraviolet reaction container are included, device rack is installed as whole base body, carries each function unit;Pre-depth purification unit is fixed on device rack, is made of depth desulfurization component and depth drying component in series, for removing impurities in original methanation tail gas and completely stripping water vapor;First mixed constant temperature container is arranged at the gas outlet side of pre-depth purification unit, the side wall is provided with A and B ports for gas inlet, is equipped with turbulence mixing component and constant temperature component inside, realizes the uniform mixing of dry tail gas and ozone and constant temperature control.

Description

Technical Field

[0001] This invention belongs to the field of purification device technology, and specifically relates to a purification device for ozone degradation of chemical methanation tail gas. Background Technology

[0002] The methanation process in coal-to-natural-gas and coke oven gas production continuously emits methanation off-gas, which contains low concentrations of methane, carbon monoxide, trace amounts of organic sulfides, and saturated water vapor. Direct emission of this gas causes greenhouse gas pollution and atmospheric odor pollution. Current mainstream treatment processes include thermal incineration and pressure swing adsorption (PSA). Thermal incineration requires continuous fuel replenishment to maintain high temperatures, resulting in high overall energy costs. PSA only separates gas components and cannot deeply degrade low-concentration methane pollutants.

[0003] Existing ozone ultraviolet degradation purification equipment mostly adopts a single-chamber integrated structure, where gas mixing, temperature control, water vapor replenishment, and ultraviolet degradation are all completed within the same chamber. In actual use, this structure suffers from mutual interference between the operating conditions of each process. The wet reaction environment can cause scaling and corrosion of the heat exchange structure. Simultaneously, the large fluctuations in the initial exhaust gas's water vapor and impurities lead to poor ozone mixing uniformity, unstable free radical generation, and inconsistent methane degradation effects. This easily results in incomplete degradation and byproduct residues, making it difficult to guarantee the equipment's operational stability and purification accuracy.

[0004] Existing technologies have at least the following problems during use: traditional single-chamber purification equipment cannot achieve decoupled control of dry and wet conditions, has large fluctuations and interference in exhaust gas conditions, and has core defects such as uneven ozone mixing, uncontrollable reaction parameters, easy corrosion and aging of equipment, and poor stability of methane degradation. Summary of the Invention

[0005] This invention provides a chemical methanation tail gas ozone degradation purification device to solve the technical problems of existing single-chamber purification equipment, such as the inability to achieve decoupled control of dry and wet conditions, large fluctuations in tail gas conditions, uneven ozone mixing, uncontrollable reaction parameters, easy corrosion and aging of equipment, and poor stability of methane degradation.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: An ozone degradation and purification device for chemical methanation tail gas includes a device frame, a pre-treatment deep purification unit, a first mixing and constant-temperature container, a precision humidification unit, and a second ultraviolet reaction container. The device frame is an integral mounting base used to support each functional unit. The pre-treatment deep purification unit is fixedly mounted on the device frame and includes a deep desulfurization component and a deep drying component arranged in series for removing impurities and stripping moisture from the raw methanation tail gas. The first mixing and constant-temperature container is fixedly mounted on the device frame and located on the outlet side of the pre-treatment deep purification unit. The first mixing thermostatic container has an A inlet port and a B inlet port through its side wall. A turbulence mixing component and a thermostatic component are fixedly installed inside the first mixing thermostatic container. The precision humidification unit is fixedly mounted between the first mixing thermostatic container and the second ultraviolet reaction container through the connecting pipe. The precision humidification unit is a gaseous micro-water replenishment structure. The second ultraviolet reaction container is fixedly mounted on the device frame and connected to the air outlet of the precision humidification unit. An ultraviolet excitation light source component is fixedly installed inside the second ultraviolet reaction container. An air outlet port C is through its bottom end of the second ultraviolet reaction container.

[0007] Furthermore, the first mixing constant temperature container and the second ultraviolet reaction container are independent closed pressure-bearing cavity structures, which are connected by a closed pipeline to form a physical isolation structure between the dry mixing cavity and the wet reaction cavity.

[0008] Furthermore, the turbulent mixing component includes multiple sets of staggered baffles, which are arranged at equal intervals along the air intake direction of the first mixing thermostatic container to form a reciprocating turbulent mixing channel.

[0009] Furthermore, the constant temperature component is a laterally distributed embedded plate heater. The plate heater is embedded and fixed in the inner wall of the first mixing constant temperature container cavity, and is fitted to the inner wall of the container. The heat exchange plate surface is arranged parallel to the gas flow direction and is evenly distributed laterally along the side wall of the cavity to achieve full-range constant temperature control of the dry mixed gas.

[0010] Furthermore, the precision humidification unit is arranged adjacent to the air inlet port of the second ultraviolet reaction container, and the water replenishment output end of the precision humidification unit is coaxially connected to the air inlet port of the second ultraviolet reaction container.

[0011] Furthermore, the ultraviolet excitation light source assembly includes multiple sets of quartz sleeves and ultraviolet lamps. The multiple sets of quartz sleeves are vertically arrayed and fixed inside the second ultraviolet reaction vessel, and the ultraviolet lamps are correspondingly nested inside the quartz sleeves.

[0012] Furthermore, the deep desulfurization component is a fixed-bed adsorption chamber structure, the deep drying component is a molecular sieve adsorption drying chamber structure, and the outlet end of the deep desulfurization component is in sealed communication with the inlet end of the deep drying component.

[0013] Furthermore, a residual ozone depletion unit is also fixedly installed on the device frame, and the inlet end of the residual ozone depletion unit is in sealed communication with the C outlet port of the second ultraviolet reaction vessel.

[0014] This invention provides an ozone degradation and purification device for chemical methanation tail gas, with the following beneficial effects: By setting up independent first mixing isothermal containers and second UV reaction containers, the physical decoupling of dry mixing isothermal conditions and wet UV degradation conditions is achieved, effectively avoiding corrosion of the heat exchange structure by wet water vapor, significantly reducing equipment failure rate, and extending equipment lifespan. A pre-treatment deep purification unit thoroughly removes impurities and raw water vapor from the exhaust gas, unifies the intake baseline, eliminates interference from exhaust gas fluctuations, and, in conjunction with a precise humidification unit, achieves quantitative and controllable reaction water vapor, significantly improving the stability and repeatability of the methane degradation reaction. The turbulent mixing and isothermal components inside the first mixing isothermal container achieve uniform mixing and constant temperature control of dry exhaust gas and ozone, preventing premature ozone decomposition at high temperatures and reducing ozone consumable consumption and operating energy consumption. The adjacent precise humidification structure design shortens the wet mixed gas transport distance, reduces ozone pre-decomposition loss, ensures precise matching of UV reaction system parameters, effectively improves the thoroughness of methane degradation, and eliminates byproduct residues. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a chemical methanation tail gas ozone degradation and purification device provided in an embodiment of the present invention; Figure 2 This is a top view of a chemical methanation tail gas ozone degradation and purification device provided in an embodiment of the present invention; Figure 3 For along Figure 2 A cross-sectional view of the AA path unfolded in the middle.

[0017] In the diagram: 1-device frame; 2-pre-processing deep purification unit; 21-deep desulfurization component; 22-deep drying component; 3-first mixing and constant temperature container; 31-A-inlet port; 32-B-inlet port; 33-turbulent mixing component; 34-constant temperature component; 4-precision humidification unit; 5-second ultraviolet reaction container; 51-ultraviolet excitation light source component; 52-C-outlet port. Detailed Implementation

[0018] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0019] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to welding, bolting, or riveting; they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] Example: like Figures 1 to 3 As shown, a chemical methanation tail gas ozone degradation and purification device includes a device frame 1, a pre-treatment deep purification unit 2, a first mixing constant temperature container 3, a precision humidification unit 4, a second ultraviolet reaction container 5, and a residual ozone decomposition unit. Each functional unit is modularly fixed on the device frame 1, and the overall layout is compact and adaptable to the installation and maintenance needs of chemical sites.

[0023] The pre-treatment deep purification unit 2 consists of a deep desulfurization component 21 and a deep drying component 22 connected in series in a closed manner. The deep desulfurization component 21 adopts a fixed-bed adsorption chamber structure and is filled with desulfurization adsorbent. It can completely remove trace amounts of organic sulfur and hydrogen sulfide impurities from the methanation tail gas, avoiding the quenching of free radicals by sulfides and corrosion of downstream equipment. The deep drying component 22 adopts a molecular sieve adsorption drying chamber structure, which can deeply dehydrate the desulfurized tail gas, completely remove the fluctuating water vapor in the original tail gas, unify the baseline of the inlet parameters, and completely eliminate the interference of front-end operating condition fluctuations on the subsequent degradation reaction.

[0024] The first mixing constant-temperature container 3 and the second ultraviolet reaction container 5 are independent, sealed pressure chambers connected by a short-distance sealed pipeline, achieving physical decoupling between the dry mixing constant-temperature condition and the wet ultraviolet degradation condition. The first mixing constant-temperature container 3 has an A inlet port 31 and a B inlet port 32 on its side wall. The A inlet port 31 connects to the outlet of the pre-treatment deep purification unit 2, inputting dry and clean methanation tail gas. The B inlet port 32 connects to an external ozone generator, inputting high-purity ozone.

[0025] The first mixing constant-temperature container 3 is equipped with a turbulent mixing component 33, which includes a fixed turbulent structure and a dynamic turbulent structure. The fixed turbulent structure consists of multiple sets of staggered and equally spaced baffles, forming a reciprocating turbulent mixing channel along the air intake direction, which can initially deflect and mix the dry exhaust gas and ozone entering the cavity. At the same time, a blade turbulent structure is rotatably mounted at the center of the cavity. The blades can be passively rotated based on the airflow pressure difference to perform secondary cutting, dispersion, and turbulence on the deflected mixed gas. Through the composite turbulent structure of fixed baffles and dynamic rotating blades, the dry exhaust gas and ozone can be forced to fully mix in a turbulent manner, completely eliminating local concentration unevenness, laminar dead zones, and airflow deviation problems, significantly improving the mixing uniformity of the two gases, and ensuring that the gas component ratios entering subsequent reaction processes are uniform and stable.

[0026] The container's inner wall is laterally embedded with fixed plate heaters as a temperature control component 34. The plate heaters are arranged laterally along the inner wall of the cavity, with the heat exchange plates parallel to the gas flow direction. This does not obstruct the airflow channel or increase the system pressure drop. It can perform full-range, uniform, and precise temperature control of the dry mixed gas inside the cavity, keeping the mixing temperature stably controlled within the ozone safe and stable range. This effectively avoids premature thermal decomposition and loss of ozone caused by high temperatures. At the same time, the dry, sealed cavity environment can completely prevent scale, corrosion, and dust accumulation on the heaters, resulting in high long-term operational stability.

[0027] The dry, constant-temperature mixed gas in the first mixing constant-temperature container 3 is transported to the precision humidification unit 4 via pipeline. The precision humidification unit 4 is coaxially arranged next to the air inlet port of the second ultraviolet reaction container 5. It adopts a gaseous micro-water replenishment structure, which can quantitatively replenish gaseous water vapor to the mixed gas, precisely matching the free radical generation water vapor conditions required for the ultraviolet degradation reaction. Moreover, the short-distance docking structure minimizes the transport path of the wet mixed gas and reduces ozone pre-decomposition loss.

[0028] The second ultraviolet reaction vessel 5 houses a vertically arrayed ultraviolet excitation light source assembly 51. Ultraviolet lamps are nested within a quartz sleeve, stably emitting specific wavelengths of ultraviolet light to excite ozone decomposition and generate highly oxidizing hydroxyl radicals. These radicals break the CH chemical bonds of methane through a free radical chain reaction, progressively mineralizing methane in the exhaust gas into carbon dioxide and water, thus achieving complete pollutant degradation. The purified exhaust gas is discharged through the C-type outlet port 52 at the bottom of the second ultraviolet reaction vessel 5 and connected to a residual ozone decomposition unit. Residual escaped ozone is completely removed through catalytic decomposition, ultimately achieving compliant exhaust gas emissions.

[0029] In summary, this invention utilizes a widened herringbone corrugated plate with a large wave pitch to construct a dedicated plate-type mixing channel, reducing pressure drop and preventing impurity blockage. Through pre-treatment of pre-gas-water separation and desulfurization adsorption, it removes water vapor and sulfur impurities from the tail gas, protecting the mixing structure and catalytic packing. A layered, multi-point ozone distribution structure achieves uniform mixing of a thin ozone layer, reducing ozone loss. A rear-mounted buffer gas equalization chamber with staggered baffles eliminates stratification of airflow velocity and concentration, stabilizing catalytic degradation conditions. A four-corner limiting and clamping mechanism for the plates prevents plate misalignment and airflow bypass. Combined with a perfluorinated corrosion-resistant seal, a pressure-bearing explosion-proof housing, and a PLC-linked automatic control system, the entire device is adaptable to complex conditions of high humidity, trace sulfur content, and pressure fluctuations in methanation off-gas tail gas. It boasts high ozone utilization, thorough low-temperature methane degradation, and a longer equipment maintenance cycle, enabling low-cost, stable, and compliant purification of chemical methanation tail gas.

[0030] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope described in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A chemical methanation tail gas ozone degradation and purification device, comprising a device frame (1), a pre-treatment deep purification unit (2), a first mixing constant temperature container (3), a precision humidification unit (4), and a second ultraviolet reaction container (5), characterized in that, The device frame (1) is an integral mounting base used to support each functional unit; the pre-deep purification unit (2) is fixedly installed on the device frame (1), and the pre-deep purification unit (2) includes a deep desulfurization component (21) and a deep drying component (22) arranged in series, used to remove impurities and strip water vapor from the original methanation tail gas; the first mixing constant temperature container (3) is fixedly installed on the device frame (1) and located on the outlet side of the pre-deep purification unit (2), and the side wall of the first mixing constant temperature container (3) is provided with an A inlet port (31) and a B inlet port (32), and the first mixing constant temperature container (3) is fixedly provided with a turbulence mixing component (33) and a constant temperature component (34); the precision humidification unit (4) is fixedly installed between the connecting pipe of the first mixing constant temperature container (3) and the second ultraviolet reaction container (5), and the precision humidification unit (4) is a gaseous micro-water replenishment structure; The second ultraviolet reaction container (5) is fixedly installed on the device frame (1) and connected to the air outlet of the precision humidification unit (4). The ultraviolet excitation light source assembly (51) is fixedly installed inside the second ultraviolet reaction container (5). The bottom end of the second ultraviolet reaction container (5) is provided with a C air outlet port (52).

2. The ozone degradation and purification device for chemical methanation tail gas according to claim 1, characterized in that, The first mixing constant temperature container (3) and the second ultraviolet reaction container (5) are independent closed pressure chamber structures. They are connected by a closed pipeline to form a physical isolation structure between the dry mixing chamber and the wet reaction chamber.

3. The ozone degradation and purification device for chemical methanation tail gas according to claim 2, characterized in that, The turbulent mixing component (33) includes multiple sets of staggered baffles. The multiple sets of baffles are arranged at equal intervals along the air intake direction of the first mixing thermostatic container (3) to form a reciprocating turbulent mixing channel.

4. The ozone degradation and purification device for chemical methanation tail gas according to claim 3, characterized in that, The thermostatic component (34) is embedded and fixed in the inner wall of the cavity of the first mixing thermostatic container (3). The thermostatic component (34) is fitted to the inner wall of the container, and the heat exchange plate is arranged parallel to the gas flow direction.

5. The ozone degradation and purification device for chemical methanation tail gas according to claim 4, characterized in that, The precision humidification unit (4) is arranged close to the air inlet port of the second ultraviolet reaction container (5), and the water replenishment output end of the precision humidification unit (4) is coaxially connected to the air inlet port of the second ultraviolet reaction container (5).

6. The ozone degradation and purification device for chemical methanation tail gas according to claim 5, characterized in that, The ultraviolet excitation light source assembly (51) includes multiple sets of quartz sleeves and ultraviolet lamps. The multiple sets of quartz sleeves are vertically arrayed and fixed inside the second ultraviolet reaction container (5). The ultraviolet lamps are correspondingly nested inside the quartz sleeves.

7. The ozone degradation and purification device for chemical methanation tail gas according to claim 6, characterized in that, The deep desulfurization component (21) is a fixed bed adsorption chamber structure, and the deep drying component (22) is a molecular sieve adsorption drying chamber structure. The outlet end of the deep desulfurization component (21) is in sealed communication with the inlet end of the deep drying component (22). A residual ozone decomposition unit is also fixedly installed on the device frame (1). The inlet end of the residual ozone decomposition unit is in sealed communication with the C outlet port (52) of the second ultraviolet reaction vessel (5).

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