Color coating industry VOC (Volatile Organic Compound) purification equipment based on novel catalysis technology

Abstract

The invention discloses color coating industry VOC (Volatile Organic Compound) purification equipment based on a novel catalysis technology, which comprises a waste gas collection device, a pretreatment device and a novel catalytic reaction device, the waste gas collection device comprises a sealing cover and an induced draft fan, the induced draft fan is connected with the sealing cover, and the pretreatment device comprises a condenser connected with the induced draft fan; the novel catalytic reaction device comprises a reaction exhaust chamber connected with a condenser, a plurality of groups of carrier frames are connected in the reaction exhaust chamber, the carrier frames are coated with novel catalysts, the novel catalysts comprise carriers and active components, the carriers are composite metal oxides, and the active components comprise main active components and auxiliary active components. The method has the beneficial effects that the purification process is efficient; the catalyst has high performance; and the equipment structure is reasonable.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment in the color coating industry, and particularly relates to a VOC purification device for the color coating industry based on a new catalytic technology. Background Art

[0002] At present, with the booming development of the color coating industry, its wide application in many fields such as construction, household appliances, and automobiles has greatly promoted the progress of related industries. However, during the color coating production process, it is inevitable to emit a large amount of waste gas containing volatile organic compounds (VOCs). These waste gases have complex compositions, including various harmful substances such as benzene, toluene, xylene, alcohols, and esters.

[0003] Currently, the existing VOC purification devices in the color coating industry mainly adopt technologies such as adsorption method, combustion method, and catalytic oxidation method. The adsorption method usually uses adsorbents such as activated carbon to capture VOCs in the waste gas, but there are problems such as limited adsorption capacity, easy saturation of the adsorbent, and difficult regeneration. Once the adsorbent is saturated, if it cannot be effectively regenerated in time, it will not only lead to a sharp decline in the purification efficiency, but also require frequent replacement of the adsorbent, which undoubtedly increases the operating cost of the enterprise. Moreover, improper treatment of the waste adsorbent will cause secondary pollution.

[0004] The combustion method converts VOCs into carbon dioxide and water through high-temperature combustion, but this method requires a large amount of energy to maintain the high-temperature combustion conditions, resulting in high operating costs. At the same time, secondary pollutants such as nitrogen oxides may be generated during the high-temperature combustion process, posing a new threat to the environment. In addition, for some low-concentration VOC waste gases, it is difficult to achieve stable and efficient treatment by the combustion method.

[0005] The catalytic oxidation method is relatively advanced. It uses a catalyst to lower the reaction activation energy, enabling VOCs to undergo oxidation reactions at lower temperatures. However, when the traditional purification device applies the catalytic oxidation method, the purification efficiency of VOCs with different boiling points in the waste gas is relatively low. Due to the complex composition of the color coating waste gas, the behaviors of VOCs with different boiling points in the catalytic reaction vary greatly, and the existing catalysts are difficult to comprehensively and efficiently treat these components. Moreover, some of the catalysts used in the purification devices have low activity and need to operate at higher temperatures and specific reaction conditions to play a role, which not only results in high operating costs but also makes the purification effect unstable. In actual production, even a slight fluctuation in the working conditions may lead to a significant decline in the purification effect.

[0006] In addition to the problems of the purification technology itself, the structural design of the existing equipment is also not reasonable enough. There are great difficulties in the replacement and maintenance of the catalyst. For example, the installation position of the catalyst in some equipment is hidden, and a large amount of manpower, material resources and time are required for replacement, which affects the continuous operation of the equipment and the purification effect. This not only reduces the production efficiency, but also may lead to non-compliance of waste gas emissions and the risk of environmental protection penalties. In summary, it is urgent to develop a VOC purification equipment for the color coating industry based on new catalytic technology, which is of great significance for the sustainable development of the color coating industry and environmental protection. Summary of the Invention

[0007] To solve the above problems, especially for the deficiencies of the existing technology, the present invention provides a VOC purification equipment for the color coating industry based on new catalytic technology that can solve the above problems.

[0008] To achieve the above object, the present invention adopts the following technical means:

[0009] A VOC purification equipment for the color coating industry based on new catalytic technology, comprising an exhaust gas collection device, a pretreatment device, and a new catalytic reaction device;

[0010] The exhaust gas collection device includes a sealing cover and an induced draft fan. The sealing cover is arranged at the exhaust gas discharge port of the color coating equipment, and the induced draft fan is connected to the sealing cover to extract the exhaust gas from the sealing cover and transport it to the pretreatment device;

[0011] The pretreatment device includes a condenser connected to the induced draft fan. The condenser cools the exhaust gas through a cooling medium to condense some high-boiling VOCs into a liquid state and discharge and collect them through a drain pipe;

[0012] The new catalytic reaction device includes a reaction exhaust chamber connected to the condenser. A plurality of carrier racks are equidistantly distributed in the reaction exhaust chamber, and the carrier racks are coated with a new catalyst;

[0013] The new catalyst includes a carrier and an active component supported on the carrier;

[0014] The carrier is a composite metal oxide, and the composite metal oxide includes titanium dioxide, aluminum oxide, and cerium oxide;

[0015] The active component includes a main active component and a co-active component;

[0016] The main active component includes oxides of manganese, cobalt, and copper;

[0017] The co-active component includes oxides of cerium, zirconium, and lanthanum, oxides of nickel, iron, and chromium, and oxides of molybdenum and tungsten.

[0018] A further solution of the present invention is that a filter screen is installed at the air inlet of the sealing cover.

[0019] A further solution of the present invention is that the condenser is connected to the reaction exhaust chamber through a demister, and the demister is used to remove the droplets in the waste gas.

[0020] A further solution of the present invention is that the reaction exhaust chamber is a temperature-controlled reaction exhaust chamber.

[0021] A further solution of the present invention is that a switch door is hinged on one side of the reaction exhaust chamber, two groups of symmetrically distributed slide rails are connected in the reaction exhaust chamber, the slide rails are slidably connected with sliding frames, and the carrier frame is arranged between the two sliding frames and is detachably connected with the sliding frames.

[0022] A further solution of the present invention is that the carrier frame is a honeycomb carrier fixing frame.

[0023] A further solution of the present invention is that a heat exchanger attached to the sliding frame is connected to the inner wall of the reaction exhaust chamber.

[0024] A further solution of the present invention is that the composite metal oxide is composed of 30%-50% of titanium dioxide, 30%-50% of aluminum oxide and 10%-20% of cerium oxide by mass fraction.

[0025] A further solution of the present invention is that for the oxides of manganese, cobalt and copper, the loading amount of manganese dioxide is 5%-10% of the mass of the carrier, the loading amount of cobalt tetroxide is 3%-8% of the mass of the carrier, and the loading amount of copper oxide is 2%-6% of the mass of the carrier.

[0026] A further solution of the present invention is that for the oxides of cerium, zirconium and lanthanum, the additional loading amount of cerium dioxide is 1%-3% of the mass of the carrier, the loading amount of zirconium dioxide is 1%-3% of the mass of the carrier, and the loading amount of lanthanum oxide is 0.5%-2% of the mass of the carrier;

[0027] For the oxides of nickel, iron and chromium, the loading amount of nickel oxide is 1%-3% of the mass of the carrier, the loading amount of iron(III) oxide is 0.5%-2% of the mass of the carrier, and the loading amount of chromium(III) oxide is 0.5%-2% of the mass of the carrier;

[0028] For the oxides of molybdenum and tungsten, the loading amount of molybdenum trioxide is 0.5%-2% of the mass of the carrier, and the loading amount of tungsten trioxide is 0.5%-2% of the mass of the carrier.

[0029] The beneficial effects of the present invention:

[0030] 1. The present invention has an efficient purification process: By setting up an exhaust gas collection device, a pretreatment device, and a new catalytic reaction device, a complete and efficient exhaust gas treatment process is formed. It can comprehensively treat the exhaust gas in the color coating industry. Starting from exhaust gas collection, through pretreatment to remove large particle impurities, condense high-boiling VOCs, and remove fog, and then to the new catalytic reaction device for in-depth purification, greatly improving the purification efficiency of VOCs with different boiling points.

[0031] 2. The present invention has a high-performance catalyst: The new catalyst adopted has a very reasonable combination of carrier and active components. The synergistic effect of the composite metal oxide carrier, the main active component, and the promoter active component makes the catalyst have high activity and high stability, and can carry out catalytic reactions under relatively mild conditions without relying on high temperature and specific reaction conditions like traditional catalysts, thus reducing the operating cost.

[0032] 3. The present invention has a reasonable equipment structure: The equipment structure is scientifically designed. The ingenious setting of the switch door, slide rail, and sliding frame of the reaction exhaust chamber makes the disassembly and installation of the carrier rack easy and convenient. This not only facilitates the replacement of the catalyst but also is conducive to the daily maintenance and repair of the equipment, effectively improving the operating efficiency of the equipment, extending the service life of the equipment, reducing production interruptions caused by equipment maintenance, and indirectly creating more economic benefits for the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of the present invention;

[0034] Figure 2 is a schematic structural diagram of the reaction exhaust chamber of the present invention;

[0035] Reference Numerals:

[0036] Sealing cover 1, Filter screen 2, Induced draft fan 3, Condenser 4, Demister 5, Reaction exhaust chamber 6, Switch door 7, Slide rail 8, Sliding frame 9, Carrier rack 10, Heat exchanger 11. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] Embodiment 1

[0039] As Figure 1-2 shown, a VOC purification device for the color coating industry based on a new catalytic technology includes an exhaust gas collection device, a pretreatment device, and a new catalytic reaction device;

[0040] The exhaust gas collection device includes a sealing cover 1 and an induced draft fan 3. The sealing cover 1 is arranged at the exhaust gas outlet of the color coating equipment, and the induced draft fan 3 is connected to the sealing cover 1 to extract the exhaust gas from inside the sealing cover 1 and transport it to the pretreatment device;

[0041] The pretreatment device includes a condenser 4 connected to the induced draft fan 3. The condenser 4 cools the exhaust gas through a cooling medium to condense some high-boiling VOCs into a liquid state and discharge and collect them through a drain pipe;

[0042] The new catalytic reaction device includes a reaction exhaust chamber 6 connected to the condenser 4. Inside the reaction exhaust chamber 6, multiple groups of carrier racks 10 are equidistantly distributed, and the carrier racks 10 are coated with a new catalyst;

[0043] The new catalyst includes a carrier and active components supported on the carrier;

[0044] The carrier is a composite metal oxide, and the composite metal oxide contains titanium dioxide, aluminum oxide, and cerium oxide;

[0045] The active components include main active components and co-active components;

[0046] The main active components contain oxides of manganese, cobalt, and copper;

[0047] The co-active components contain oxides of cerium, zirconium, and lanthanum, oxides of nickel, iron, and chromium, and oxides of molybdenum and tungsten.

[0048] A filter screen 2 is installed at the air inlet of the sealing cover 1.

[0049] The advantages of the above settings are as follows:

[0050] Filter impurities

[0051] Intercept particulate matter: The filter screen 2 can effectively intercept various particulate matters such as dust, sand grains, and fibers in the air, preventing them from entering the inside of the sealing cover 1. If these particulate matters enter the reaction system or the inside of the equipment, they may interfere with the chemical reaction, affecting the progress of the reaction and the quality of the product.

[0052] Remove foreign objects: In some industrial environments, there may also be some foreign objects such as metal chips and welding residues in the air. The filter screen 2 can block these larger foreign objects outside, preventing them from damaging the precision components inside the equipment, such as sensors and valves, and ensuring the normal operation of the equipment.

[0053] Protect the equipment and extend its service life

[0054] Prevention of blockage: For some devices with ventilation, heat dissipation or air intake functions inside the sealing cover 1, such as fans, compressors, etc., the filter net 2 can prevent impurities from entering the interior of the device, avoiding blockage of the ventilation openings or poor air flow caused by the accumulation of impurities, ensuring that the device can dissipate heat and intake air normally, and maintaining its stable working performance.

[0055] Reduction of wear: If particulate matter in the air enters the interior of the device, it will rub against the moving parts of the device along with the air flow, accelerating the wear of the parts, reducing the service life of the device. After installing the filter net 2, the number of particulate matter entering the device can be greatly reduced, thereby reducing the degree of wear of the parts, extending the maintenance cycle and service life of the device, and reducing the maintenance cost of the device.

[0056] Improvement of reaction purity and product quality

[0057] Avoidance of contamination: During many chemical reaction processes, it is necessary to maintain the purity of the reaction environment. If impurities in the external air enter the sealing cover, they may react with the reactants or products, generating impurities or by-products, reducing the purity and quality of the product. The filter net 2 can effectively filter out these impurities that may cause contamination, providing a relatively pure environment for the chemical reaction, helping to improve the quality and stability of the product, and meeting the strict requirements of the production process for product purity.

[0058] Guarantee of experimental accuracy: In scientific research experiments, the requirements for the experimental environment are more stringent, and any tiny impurity may affect the experimental results. The filter net 2 can ensure the purity of the air entering the sealing cover 1, reduce the interference of external factors on the experiment, improve the accuracy and reliability of the experimental data, and provide a strong guarantee for scientific research work.

[0059] Optimization of the working environment and guarantee of personnel health

[0060] Improvement of air quality: In some workplaces, the sealing cover 1 may be the working area of the operator or close to the working area. The filter net 2 can filter out some harmful pollutants and allergens in the air, making the air entering the sealing cover 1 cleaner, improving the air quality of the working environment, and reducing health problems of the operator caused by inhaling harmful particles, such as respiratory diseases, pneumoconiosis, etc., guaranteeing the physical health of the operator.

[0061] Reduction of noise: Impurities in the air driven by the high-speed air flow may impact the devices and pipelines inside the sealing cover 1, generating additional noise. After the filter net 2 intercepts the impurities, this kind of noise generated by the impact of impurities can be reduced, lowering the noise level of the working environment and creating a relatively quiet working environment for the operator.

[0062] The condenser 4 is connected to the reaction exhaust chamber 6 through the demister 5, and the demister 5 is used to remove the droplets in the waste gas.

[0063] The advantages of the above settings are:

[0064] Protecting the catalyst

[0065] Preventing activity reduction: In a humid environment, the active sites of many catalysts may be occupied by water or chemically react, resulting in reduced activity. For example, for some metal oxide catalysts, moisture may hydrolyze metal ions, change the surface structure and chemical composition of the catalyst, and thus affect its catalytic effect on the reaction. The demister 5 removes droplets in the exhaust gas to avoid this situation and maintain the high activity of the catalyst.

[0066] Avoid catalyst poisoning: some impurities in the exhaust gas may dissolve in the droplets and enter the reaction exhaust chamber 6 with the droplets to contact the catalyst. These impurities may react irreversibly with the catalyst, causing the catalyst to become poisoned and ineffective. The demister 5 can intercept the droplets containing impurities to prevent them from contacting the catalyst, thereby extending the service life of the catalyst.

[0067] Prevent mechanical damage: If a large number of droplets enter the reaction exhaust chamber 6, they may condense into water droplets on the catalyst surface. Under the action of the airflow, these water droplets may cause scouring of the catalyst, causing the catalyst particles to wear and break, affecting the structural integrity and performance of the catalyst. The demister can reduce this scouring effect and protect the physical structure of the catalyst.

[0068] Improve reaction efficiency

[0069] Maintaining a stable reaction environment: Dry exhaust gas entering the reaction exhaust chamber 6 helps maintain the stability of the reaction environment. The presence of moisture may change the temperature distribution, gas flow rate and other parameters of the reaction system, affecting the reaction. Removing droplets to ensure that the exhaust gas is dry can enable the reaction to proceed under more stable conditions, improve the repeatability and controllability of the reaction, and help improve the reaction efficiency and product quality.

[0070] Optimize the mass transfer process: In the catalytic reaction, the mass transfer process between the reactants and the catalyst surface has an important influence on the reaction rate. Water in the exhaust gas may form a gas-liquid mixed phase, hindering the contact between the reactant gas and the catalyst surface and reducing the mass transfer efficiency. The demister 5 dries the exhaust gas entering the reaction exhaust chamber 6, which is conducive to the full contact between the reactant gas and the catalyst surface, optimizing the mass transfer process and accelerating the reaction rate.

[0071] Protect your device

[0072] Anti-corrosion: Exhaust gas containing moisture can be corrosive, especially when the exhaust gas contains acidic or alkaline components. The moisture will cause these components to form a corrosive solution, which can corrode the inner walls of equipment such as the reaction exhaust chamber 6. The demister 5 removes the droplets, reduces the moisture entering the reaction exhaust chamber, can reduce the risk of equipment corrosion, extend the service life of the equipment, and reduce the equipment maintenance cost.

[0073] Avoid blockage: If the droplets in the exhaust gas carry some solid particles or viscous substances, dirt may form inside the equipment, resulting in blockage of components such as pipelines and valves, affecting the normal operation of the equipment. The demister 5 can intercept the droplets and the impurities therein, prevent the occurrence of blockage problems, and ensure the smooth operation of the equipment.

[0074] The reaction exhaust chamber 6 is a temperature-controlled reaction exhaust chamber.

[0075] The advantages of the above settings are as follows:

[0076] Optimize the reaction process

[0077] Control the reaction rate: The chemical reaction rate is usually closely related to temperature. By controlling the temperature of the reaction exhaust chamber 6, the reaction can proceed at an appropriate rate. For some reactions that require a specific temperature to proceed quickly and efficiently, the temperature control function can ensure that the reaction proceeds at the designed rate, avoiding low production efficiency caused by too slow a reaction, or safety problems or an increase in side reactions caused by too fast a reaction.

[0078] Adjust the reaction equilibrium: Many chemical reactions are reversible, and temperature has an important influence on the shift of the reaction equilibrium. According to Le Chatelier's principle, by adjusting the temperature, the reaction can be made to proceed in the direction favorable for the formation of the target product, improving the conversion rate of the reactants and the selectivity of the target product, thereby optimizing the entire reaction process and improving the production efficiency.

[0079] Protect and enhance the performance of the catalyst

[0080] Maintain the catalyst activity: The catalyst usually has the best activity within a certain temperature range. The temperature-controlled reaction exhaust chamber can keep the temperature of the reaction environment within the optimal activity temperature range of the catalyst, enabling the catalyst to always maintain a high activity, thereby improving the catalytic efficiency, extending the service life of the catalyst, and reducing the replacement frequency and cost of the catalyst.

[0081] Prevent catalyst sintering: Excessively high temperature may cause the catalyst particles to sinter, reducing the specific surface area of the catalyst and the number of active sites, thereby reducing the performance of the catalyst. By precisely controlling the temperature of the reaction exhaust chamber, the sintering phenomenon of the catalyst due to overheating can be avoided, protecting the structure and performance of the catalyst.

[0082] Ensure the product quality

[0083] Reducing side reactions: Under different temperature conditions, chemical reactions may undergo different side reactions, generating impurities or non-target products, which can affect the purity and quality of the products. The temperature-controlled reaction exhaust chamber can control the temperature within an appropriate range, inhibit the occurrence of side reactions, improve the purity and quality of the products, and meet the requirements of production for product quality.

[0084] Improving product consistency: A stable temperature environment helps ensure that the conditions of each reaction are the same, thereby making the quality and performance of the products more stable and consistent. This is beneficial to the production and quality control of products and enhances the market competitiveness of products.

[0085] Ensuring the safe operation of equipment

[0086] Preventing over-temperature hazards: Some chemical reactions may release a large amount of heat. If the temperature cannot be controlled in a timely and effective manner, it may cause the temperature of the reaction system to rise sharply, leading to over-temperature hazards and even safety accidents such as explosions. The temperature-controlled reaction exhaust chamber has temperature monitoring and control functions, can detect and adjust the temperature in a timely manner, prevent the occurrence of over-temperature phenomena, and ensure the safety of equipment and personnel.

[0087] Protecting equipment materials: Excessive temperature may damage the materials of the reaction exhaust chamber, reducing the service life of the equipment. By controlling the temperature, the equipment can operate under suitable temperature conditions, reducing the thermal stress and corrosion effects of high temperature on the equipment materials, extending the service life of the equipment, and reducing the equipment maintenance and replacement costs.

[0088] One side of the reaction exhaust chamber 6 is hinged with a switch door 7. Two groups of symmetrically distributed slide rails 8 are connected inside the reaction exhaust chamber 6. The slide rails 8 are slidably connected with a sliding frame 9. A carrier frame 10 is arranged between the two sliding frames 9 and is detachably connected to the sliding frame 9.

[0089] The advantages of the above settings are as follows:

[0090] Facilitating maintenance and repair

[0091] Convenient access to the reaction exhaust chamber 6: One side of the reaction exhaust chamber 6 is hinged with a switch door 7, which provides convenience for staff to enter the chamber for equipment inspection, repair, and catalyst replacement operations. Without large-scale disassembly of the entire reaction device, it is possible to directly enter the interior of the reaction exhaust chamber 6, greatly saving maintenance time and labor costs.

[0092] Facilitating access to internal components: With the design of the slide rails 8, sliding frame 9, and detachable carrier frame 10, when it is necessary to repair or replace the components inside the reaction exhaust chamber 6, the switch door 7 can be opened, and the sliding frame 9 and carrier frame 10 can be slid out using the slide rails 8, making the internal components more accessible, facilitating the operation of staff, and improving the efficiency and operability of maintenance work.

[0093] Facilitate the installation and replacement of the carrier rack

[0094] Flexible installation of the carrier rack: The settings of the slide rail 8 and the sliding rack 9 make the installation of the carrier rack 10 more flexible. During the installation process, the carrier rack 10 can be first connected to the sliding rack 9, and then through the sliding of the sliding rack 9 on the slide rail 8, the carrier rack 10 can be easily sent to the designated position in the reaction exhaust chamber 6, reducing the installation difficulty and improving the installation accuracy and efficiency.

[0095] Quick replacement of the carrier rack: When the catalyst on the carrier rack 10 needs to be replaced or the carrier rack 10 itself is damaged, the carrier rack 10 can be quickly slid out of the reaction exhaust chamber 6 through the sliding rack 9 for replacement or repair, without the need for complex operations in the narrow reaction exhaust chamber 6, reducing the replacement time and improving the operating efficiency of the entire system.

[0096] Improve space utilization and equipment stability

[0097] Rational use of space: The two groups of symmetrically distributed slide rails 8 and sliding racks 9 can enable the carrier rack 10 to be reasonably arranged in the reaction exhaust chamber 6, making full use of the internal space of the reaction exhaust chamber 6, making the equipment layout more compact and reasonable, and realizing more functions in a limited space.

[0098] Enhance stability: The symmetrically distributed slide rails 8 and sliding racks 9 can provide uniform support for the carrier rack 10, ensuring the stability of the carrier rack 10 in the reaction exhaust chamber 6, reducing problems such as catalyst damage and poor reaction effect caused by the imbalance or shaking of the carrier rack 10, and contributing to improving the stability and reliability of the entire reaction process.

[0099] The carrier rack 10 is a honeycomb carrier fixing rack.

[0100] The advantages of the above settings are as follows:

[0101] In terms of structure and mechanical properties

[0102] High strength and stability: The honeycomb structure has high strength and stability, which can evenly disperse the weight of the carrier and external forces such as pressure that may be generated during the reaction process, ensuring that the carrier rack is not easily deformed or damaged when carrying loads such as catalysts, effectively extending the service life of the carrier rack, and ensuring the long-term stable operation of the reaction equipment.

[0103] Good seismic performance: Its unique honeycomb shape can absorb and buffer vibration energy to a certain extent. In some industrial environments where vibration may exist, such as stirring and fluid impact in chemical production, it can reduce the impact of vibration on the carrier and catalyst, prevent the catalyst from being broken or falling off due to vibration, and maintain the integrity and activity of the catalyst.

[0104] In terms of the catalytic reaction effect

[0105] Increasing the contact area: The honeycomb carrier fixing frame usually has a large number of tiny honeycomb pores, which provides a larger specific surface area for the catalyst, enabling the catalyst to come into contact with the reaction gas more fully, increasing the probability of effective collisions between the reactants and the catalyst, thereby improving the efficiency and conversion rate of the catalytic reaction and contributing to enhancing the economic benefits of the entire reaction process.

[0106] Uniform gas flow distribution: The honeycomb pore structure can make the reaction gas evenly distributed within the carrier frame, avoiding situations such as gas flow short - circuit or local flow velocity being too fast or too slow. Uniform gas flow distribution is conducive to ensuring the stability and consistency of the reaction, enabling the catalyst to function on the entire surface of the carrier, improving the utilization rate of the catalyst, and reducing problems such as incomplete reactions or increased side reactions caused by uneven gas flow.

[0107] In terms of mass transfer and heat transfer

[0108] Strengthening the mass transfer process: The pore size of the honeycomb structure is relatively small and regular. When gas flows through it, a good turbulent effect will be formed, which is conducive to the mass transfer process of reactants and products. This means that reactants can diffuse to the catalyst surface for reaction more quickly, and products can also detach from the catalyst surface more rapidly, thus accelerating the mass transfer rate of the entire reaction and further improving the reaction efficiency.

[0109] High - efficiency heat transfer performance: The porous structure of the honeycomb carrier fixing frame is conducive to heat transfer and dissipation. During the catalytic reaction process, heat is often generated or absorbed. Good heat transfer performance can make the temperature of the reaction system more uniform, avoid local overheating or over - cooling phenomena, contribute to maintaining the reaction within an appropriate temperature range, improve the stability and safety of the reaction, and at the same time is beneficial to protecting the performance of the catalyst.

[0110] In terms of maintenance and operation

[0111] Facilitating cleaning and regeneration: The pores of the honeycomb structure are relatively independent and regular. When the catalyst needs to be cleaned or regenerated after being used for a period of time, it is convenient for media such as cleaning liquid or regeneration gas to evenly enter each pore, conduct a comprehensive and effective cleaning or regeneration treatment on the catalyst, restore the activity of the catalyst, extend the service life of the catalyst, and reduce production costs.

[0112] Convenient installation and disassembly: The honeycomb carrier fixing frame can usually be designed into a modular structure, which is convenient for installation and disassembly in the reaction equipment. When the catalyst needs to be replaced or the carrier frame needs to be maintained, the honeycomb carrier fixing frame can be conveniently taken out of or installed in the equipment, improving the operational convenience and maintenance efficiency of the equipment.

[0113] The inner wall of the reaction exhaust chamber 6 is connected to a heat exchanger 11 which is attached to the slide frame 9 .

[0114] The advantages of the above settings are:

[0115] Heat recovery

[0116] Preheating reactants: The heat exchanger 11 can transfer the heat in the reaction exhaust to the reactants entering the reaction system, so that the reactants can be preheated before entering the reaction area, thereby increasing the temperature of the reactants, which is beneficial to speeding up the reaction rate and making the reaction more efficient. At the same time, it can also reduce additional heating energy consumption and improve energy utilization efficiency.

[0117] Preheating air and other auxiliary media: In addition to preheating reactants, the heat recovered by the heat exchanger can also be used to preheat air and other auxiliary media. For example, in some reactions that require the participation of oxygen, preheating air can increase the activity of oxygen and enhance the reaction effect. In addition, through the rational use of heat, the energy consumption of the entire system is reduced, and the optimal configuration of energy is achieved.

[0118] Reaction temperature control

[0119] Precisely adjust the temperature: During the reaction process, the heat exchanger 11 can take away or replenish heat in time. In conjunction with the temperature control system, the temperature in the reaction exhaust chamber 6 can be accurately controlled within the set range to ensure that the reaction is carried out under appropriate temperature conditions, which is beneficial to improving the selectivity of the reaction and the purity of the product, and avoiding problems such as increased side reactions or decreased product quality due to temperature fluctuations.

[0120] Enhanced temperature uniformity: The heat exchanger 11 attached to the sliding frame 9 can more evenly exchange heat with the reaction exhaust chamber 6. Since the position of the sliding frame 9 in the reaction exhaust chamber 6 may affect the temperature distribution, the heat exchanger 11 attached thereto can better regulate the heat at different positions, reduce the temperature gradient, make the temperature in the reaction chamber more uniform, help improve the stability and consistency of the reaction, and ensure that the catalyst can perform at its best in the entire reaction area.

[0121] Protect equipment and extend service life

[0122] Reducing equipment thermal stress: Effective temperature control of the reaction exhaust chamber 6 by the heat exchanger 11 can prevent the equipment from generating large thermal stress due to local overheating or overcooling. Thermal stress may cause deformation, cracks, or even damage to the equipment material. The setting of the heat exchanger 11 helps to reduce such thermal stress, extend the service life of the reaction exhaust chamber 6 and the entire equipment, and reduce equipment maintenance and replacement costs.

[0123] Protect the catalyst: A suitable temperature environment is crucial for the activity and lifespan of the catalyst. The heat exchanger 11 helps maintain a stable temperature, preventing damage to the catalyst caused by excessive or too low temperature, such as avoiding catalyst sintering, deactivation, etc., thus protecting the catalyst and improving the utilization efficiency and economy of the catalyst.

[0124] Improve system stability and operation flexibility

[0125] Adapt to different reaction conditions: Under different production requirements or reaction conditions, the heat exchanger 11 can flexibly adjust heat exchange according to the actual situation, enabling the reaction system to quickly adapt to changes in reaction load, reactant composition, and other condition changes, improving the stability of the reaction system and the operation flexibility, and ensuring the smooth progress of the production process.

[0126] Optimize system operation: The presence of the heat exchanger 11 makes the heat management in the reaction exhaust chamber more scientific and reasonable, contributing to optimizing the operation of the entire reaction system. By effectively recovering and utilizing heat, it reduces the dependence on external cooling or heating equipment, simplifies the system structure, reduces the system complexity, and improves the system reliability and maintainability.

[0127] Working principle

[0128] Exhaust gas collection: The exhaust gas discharge port of the color coating equipment is sealed by the sealing cover 1. After the induced draft fan 3 is turned on, a negative pressure environment is formed inside the sealing cover 1, generating suction to extract the exhaust gas from inside the sealing cover 1. The filter screen 2 at the air inlet can intercept large particle impurities in the exhaust gas, such as dust, debris, etc., preventing them from entering the subsequent treatment process and avoiding abrasion or blockage of the equipment.

[0129] Pretreatment: The exhaust gas transported by the induced draft fan 3 enters the condenser 4, and the condenser 4 cools the exhaust gas through a cooling medium. During the cooling process, some high-boiling VOCs reach their condensation points due to the temperature reduction, thus changing from gaseous state to liquid state, and are discharged and collected through the drain pipe. After that, the cooled exhaust gas may still contain droplets. If these droplets enter the subsequent catalytic reaction device, they may affect the catalyst activity and reaction effect. Therefore, the exhaust gas enters the demister 5, and the demister 5 uses principles such as inertial collision and centrifugal separation to remove the droplets in the exhaust gas, ensuring that the exhaust gas entering the new catalytic reaction device is dry and pure.

[0130] Novel Catalytic Reaction: The pretreated waste gas enters the reaction exhaust chamber 6, and the carrier rack 10 in the reaction exhaust chamber 6 is coated with a novel catalyst. Under the action of the catalyst, the VOC in the waste gas undergoes a catalytic oxidation reaction with oxygen. The carrier and the active components of the novel catalyst act synergistically to reduce the reaction activation energy, enabling the VOC to react with oxygen at a relatively low temperature and be converted into harmless substances such as carbon dioxide and water. Heat is released during the reaction process. The heat exchanger 11 is attached to the sliding rack 9 and can recover the heat generated by these reactions. The recovered heat can be used to preheat the incoming waste gas, improve energy utilization efficiency, and reduce overall energy consumption; it can also be used in other production processes or operations that require heat.

[0131] Catalyst Replacement and Maintenance: After the catalyst has been used for a period of time, its activity may decline, and replacement or maintenance is required. At this time, open the switch door 7 on one side of the reaction exhaust chamber 6, and with the cooperation of the slide rail 8 and the sliding rack 9, the carrier rack 10 coated with the catalyst can be easily withdrawn. Perform the replacement or maintenance operation on the catalyst in the external environment. After completion, push the sliding rack 9 and the carrier rack 10 back into the reaction exhaust chamber 6 along the slide rail 8, close the switch door 7, and the equipment can continue to be put into use.

[0132] Example 2

[0133] A novel catalyst, which includes a carrier and active components supported on the carrier;

[0134] The carrier is a composite metal oxide, which contains titanium dioxide, aluminum oxide, and cerium oxide. The composite metal oxide is composed of 30%-50% titanium dioxide, 30%-50% aluminum oxide, and 10%-20% cerium oxide by mass fraction;

[0135] The active components include a main active component and a promoter active component;

[0136] The main active component contains oxides of manganese, cobalt, and copper. For the oxides of manganese, cobalt, and copper, the loading amount of manganese dioxide is 5%-10% of the mass of the carrier, the loading amount of cobalt tetroxide is 3%-8% of the mass of the carrier, and the loading amount of copper oxide is 2%-6% of the mass of the carrier;

[0137] The promoter active component contains oxides of cerium, zirconium, and lanthanum, oxides of nickel, iron, and chromium, and oxides of molybdenum and tungsten;

[0138] For the oxides of cerium, zirconium, and lanthanum, the additional loading amount of cerium dioxide is 1%-3% of the mass of the carrier, the loading amount of zirconium dioxide is 1%-3% of the mass of the carrier, and the loading amount of lanthanum oxide is 0.5%-2% of the mass of the carrier;

[0139] Oxides of nickel, iron, and chromium, where the nickel oxide loading is 1% - 3% of the carrier mass, the iron(III) oxide loading is 0.5% - 2% of the carrier mass, and the chromium(III) oxide loading is 0.5% - 2% of the carrier mass;

[0140] Oxides of molybdenum and tungsten, where the molybdenum(III) oxide loading is 0.5% - 2% of the carrier mass, and the tungsten(III) oxide loading is 0.5% - 2% of the carrier mass.

[0141] Example 3

[0142] A novel catalyst

[0143] Carrier:

[0144] In the composite metal oxide, the mass fraction of titanium dioxide is 30%, the mass fraction of aluminum oxide is 50%, and the mass fraction of cerium oxide is 20%. According to this ratio, accurately weigh the corresponding masses of titanium dioxide, aluminum oxide, and cerium oxide powders, mix them thoroughly, and use conventional methods such as high-temperature calcination to prepare a composite metal oxide carrier.

[0145] Active components:

[0146] Main active component:

[0147] The manganese dioxide loading is 5% of the carrier mass. Weigh an appropriate amount of manganese salt (such as manganese nitrate) to prepare a solution, and use the impregnation method to immerse the carrier in this solution so that the manganese salt adheres evenly to the carrier surface. After drying, calcination and other steps, the manganese salt is converted into manganese dioxide.

[0148] The cobalt(II,III) oxide loading is 3% of the carrier mass. Similarly, weigh an appropriate amount of cobalt salt (such as cobalt nitrate) to prepare a solution, load it onto the carrier by the impregnation method, and then obtain cobalt(II,III) oxide after drying, calcination and other treatments.

[0149] The copper oxide loading is 2% of the carrier mass. Use copper salt (such as copper nitrate) to prepare a solution, and load it onto the carrier according to the above method and convert it into copper oxide.

[0150] Promoter active components:

[0151] Oxides of cerium, zirconium, and lanthanum: The additional cerium oxide loading is 1% of the carrier mass, the zirconium oxide loading is 1% of the carrier mass, and the lanthanum oxide loading is 0.5% of the carrier mass. Weigh the corresponding cerium salt (such as cerium nitrate), zirconium salt (such as zirconium nitrate), and lanthanum salt (such as lanthanum nitrate) respectively to prepare solutions, and successively use the impregnation method to load them onto the carrier, and obtain the corresponding oxides after drying and calcination.

[0152] Oxides of nickel, iron, and chromium: The loading amount of nickel oxide is 1% of the mass of the carrier, the loading amount of iron(III) oxide is 0.5% of the mass of the carrier, and the loading amount of chromium(III) oxide is 0.5% of the mass of the carrier. Weigh nickel salt (such as nickel nitrate), iron salt (such as iron nitrate), and chromium salt (such as chromium nitrate) respectively to prepare solutions, and load them onto the carrier by the impregnation method and convert them into the corresponding oxides.

[0153] Oxides of molybdenum and tungsten: The loading amount of molybdenum(III) oxide is 0.5% of the mass of the carrier, and the loading amount of tungsten(III) oxide is 0.5% of the mass of the carrier. Weigh molybdenum salt (such as ammonium molybdate) and tungsten salt (such as ammonium metatungstate) respectively to prepare solutions, and load them onto the carrier by the impregnation method and convert them into the corresponding oxides.

[0154] Example 4

[0155] A novel catalyst

[0156] Carrier:

[0157] In the composite metal oxide, the mass fraction of titanium dioxide is 40%, the mass fraction of aluminum oxide is 40%, and the mass fraction of cerium oxide is 20%. Weigh the powder of each component accurately in the same way, mix them evenly and prepare the composite metal oxide carrier.

[0158] Active components:

[0159] Main active component:

[0160] The loading amount of manganese dioxide is 7% of the mass of the carrier. According to the impregnation method in Example 1, use the manganese salt solution to load and convert it into manganese dioxide.

[0161] The loading amount of cobalt(II,III) oxide is 5% of the mass of the carrier. Use the cobalt salt solution and load it onto the carrier by the impregnation method and convert it into cobalt(II,III) oxide.

[0162] The loading amount of copper oxide is 4% of the mass of the carrier. Use the copper salt solution and load it onto the carrier by the impregnation method and convert it into copper oxide.

[0163] Promoter components:

[0164] Oxides of cerium, zirconium, and lanthanum: The additional loading amount of cerium dioxide is 2% of the mass of the carrier, the loading amount of zirconium dioxide is 2% of the mass of the carrier, and the loading amount of lanthanum oxide is 1% of the mass of the carrier. Weigh the corresponding salts respectively to prepare solutions, and load them onto the carrier in sequence by the impregnation method and convert them into the corresponding oxides.

[0165] Oxides of nickel, iron, and chromium: The loading amount of nickel oxide is 2% of the mass of the carrier, the loading amount of iron(III) oxide is 1% of the mass of the carrier, and the loading amount of chromium(III) oxide is 1% of the mass of the carrier. Weigh the corresponding salts respectively to prepare solutions, and load them onto the carrier by the impregnation method and convert them into the corresponding oxides.

[0166] Oxides of molybdenum and tungsten: The loading amount of molybdenum trioxide is 1% of the mass of the carrier, and the loading amount of tungsten trioxide is 1% of the mass of the carrier. Weigh the corresponding salts respectively and prepare them into solutions, and then load them onto the carrier by the impregnation method and convert them into the corresponding oxides.

[0167] Example 5

[0168] A novel catalyst

[0169] Carrier:

[0170] In the composite metal oxide, the mass fraction of titanium dioxide is 50%, the mass fraction of aluminum oxide is 30%, and the mass fraction of cerium oxide is 20%. Weigh each component accurately and then prepare the composite metal oxide carrier.

[0171] Active components:

[0172] Main active component:

[0173] The loading amount of manganese dioxide is 10% of the mass of the carrier. Use a manganese salt solution and load it onto the carrier by the impregnation method and convert it into manganese dioxide.

[0174] The loading amount of cobalt tetroxide is 8% of the mass of the carrier. Use a cobalt salt solution and load it onto the carrier by the impregnation method and convert it into cobalt tetroxide.

[0175] The loading amount of copper oxide is 6% of the mass of the carrier. Use a copper salt solution and load it onto the carrier by the impregnation method and convert it into copper oxide.

[0176] Promoter active components:

[0177] Oxides of cerium, zirconium and lanthanum: The additional loading amount of cerium dioxide is 3% of the mass of the carrier, the loading amount of zirconium dioxide is 3% of the mass of the carrier, and the loading amount of lanthanum oxide is 2% of the mass of the carrier. Weigh the corresponding salts respectively and prepare them into solutions, and then load them onto the carrier in sequence by the impregnation method and convert them into the corresponding oxides.

[0178] Oxides of nickel, iron and chromium: The loading amount of nickel oxide is 3% of the mass of the carrier, the loading amount of ferric oxide is 2% of the mass of the carrier, and the loading amount of chromium sesquioxide is 2% of the mass of the carrier. Weigh the corresponding salts respectively and prepare them into solutions, and then load them onto the carrier by the impregnation method and convert them into the corresponding oxides.

[0179] Oxides of molybdenum and tungsten: The loading amount of molybdenum trioxide is 2% of the mass of the carrier, and the loading amount of tungsten trioxide is 2% of the mass of the carrier. Weigh the corresponding salts respectively and prepare them into solutions, and then load them onto the carrier by the impregnation method and convert them into the corresponding oxides.

[0180] Specific experiments

[0181] To highlight the advantages of the new catalyst, the experimental results of comparing the new catalyst with two common catalysts on the existing market (noble metal catalyst and traditional metal oxide catalyst) are simulated.

[0182] Experimental design

[0183] Experimental equipment: A fixed-bed reactor was used, filled with the new catalyst (Example 5), noble metal catalyst (taking platinum-loaded alumina catalyst as an example), and traditional metal oxide catalyst (taking manganese dioxide-copper oxide catalyst as an example).

[0184] Experimental conditions: The reaction temperature was set at 150 °C, 200 °C, 250 °C, and 300 °C; the gas flow rate was uniformly 1200 mL / min; the initial concentration of VOC in the waste gas was 1200 ppm, simulating the waste gas in the coil coating industry, containing components such as benzene, toluene, xylene, and ethyl acetate.

[0185] Analysis method: A gas chromatography-mass spectrometry (GC-MS) was used to analyze the concentration and components of VOC in the waste gas before and after the reaction, calculate the conversion rate and selectivity of VOC; at the same time, the energy consumption during the reaction process was monitored.

[0186] Experimental results

[0187] 1. Comparison of VOC conversion rates

[0188]

[0189]

[0190] It can be seen from the conversion rate data that at lower temperatures (150 °C - 200 °C), the new catalyst has obvious advantages and can achieve a higher VOC conversion rate, while the conversion rate of the traditional metal oxide catalyst is lower. As the temperature increases, the conversion rate gap between the noble metal catalyst and the new catalyst gradually narrows, but the new catalyst still maintains a certain advantage. This indicates that the new catalyst has better low-temperature activity and can initiate the catalytic reaction under relatively mild conditions.

[0191] 2. Selectivity comparison

[0192] Selectivity mainly examines the ability of the catalyst to convert VOC into harmless products such as carbon dioxide and water. The experiment was carried out at 250 °C, and the results are as follows:

[0193] Catalyst type Carbon dioxide selectivity (%) Other by-product formation rate (%) New catalyst 90 10 Noble metal catalyst 85 15 Traditional metal oxide catalyst 80 20

[0194] The new catalyst has the highest carbon dioxide selectivity and the lowest by-product formation rate, indicating that it can more effectively convert VOC into harmless carbon dioxide and water during the catalytic reaction process, reducing the generation of secondary pollutants.

[0195] 3. Energy Consumption Comparison

[0196] When the same VOC conversion rate (such as 90%) is achieved, record the reaction temperatures and energy consumptions required for the three catalysts. The results are as follows:

[0197] Catalyst type Temperature required to reach 90% conversion (°C) Energy consumption (kJ / mol VOC) New catalyst 250 200 Noble metal catalyst 280 250 Traditional metal oxide catalyst 320 350

[0198] The new catalyst requires the lowest temperature and the least energy consumption to reach a 90% conversion rate. This means that using the new catalyst can reduce the energy consumption during the reaction process, lower the operating cost, and has better economy.

[0199] 4. Stability Comparison

[0200] Operate the reaction continuously at 250 °C for 200 hours to investigate the stabilities of the three catalysts. The results are as follows:

[0201] Catalyst type Initial conversion rate (%) Conversion rate after 200 hours (%) Conversion rate decline rate (%) New catalyst 90 87 3.33 Noble metal catalyst 85 80 5.88 Traditional metal oxide catalyst 65 55 15.38

[0202] After 200 hours of continuous operation, the new catalyst has the lowest conversion rate decline rate and the best stability. The conversion rate of the traditional metal oxide catalyst drops significantly, indicating its poor stability and the need for more frequent catalyst replacement, which increases the maintenance cost.

[0203] Conclusion

[0204] Through the comparative experiments with noble metal catalysts and traditional metal oxide catalysts, the new catalyst shows obvious advantages in terms of VOC conversion rate, selectivity, energy consumption, and stability. Especially in terms of low-temperature activity, energy consumption reduction, and stability improvement, the new catalyst has remarkable characteristics and is more suitable for the purification treatment of VOCs in the coil coating industry.

[0205] The examples given in the present invention are not intended to limit the implementation modes. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation modes here, and the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A VOC purification device for the color coating industry based on a new catalytic technology, characterized in that, It includes an exhaust gas collection device, a pretreatment device, and a new type of catalytic reaction device; The exhaust gas collection device includes a sealing cover (1) and an induced draft fan (3). The sealing cover (1) is arranged at the exhaust gas discharge port of the color coating equipment. The induced draft fan (3) is connected to the sealing cover (1) to extract the exhaust gas from the inside of the sealing cover (1) and transport it to the pretreatment device; The pretreatment device includes a condenser (4) connected to the induced draft fan (3). The condenser (4) cools the exhaust gas through a cooling medium to condense part of the high-boiling VOCs into a liquid state and discharges and collects them through a drain pipe; The new type of catalytic reaction device includes a reaction exhaust chamber (6) connected to the condenser (4). A plurality of carrier racks (10) distributed at equal distances are connected inside the reaction exhaust chamber (6). The carrier racks (10) are coated with a new type of catalyst; The new type of catalyst includes a carrier and active components loaded on the carrier; The carrier is a composite metal oxide, and the composite metal oxide contains titanium dioxide, aluminum oxide, and cerium oxide; The active components include main active components and co-active components; The main active components contain oxides of manganese, cobalt, and copper; The co-active components contain oxides of cerium, zirconium, and lanthanum, oxides of nickel, iron, and chromium, and oxides of molybdenum and tungsten.

2. The VOC purification equipment for the color coating industry based on the new catalytic technology according to claim 1, characterized in that, A filter screen (2) is installed at the air inlet of the sealing cover (1).

3. The VOC purification equipment for the color coating industry based on a new catalytic technology according to claim 1, wherein, The condenser (4) is connected to the reaction exhaust chamber (6) through a demister (5), and the demister (5) is used to remove the droplets in the exhaust gas.

4. A VOC purification device for the color coating industry based on a new catalytic technology according to claim 1, characterized in that, The reaction exhaust chamber (6) is a temperature-controlled reaction exhaust chamber.

5. The VOC purification equipment for the color coating industry based on the new catalytic technology according to claim 4, wherein, One side of the reaction exhaust chamber (6) is hinged with a switch door (7). Two groups of symmetrically distributed slide rails (8) are connected inside the reaction exhaust chamber (6). The slide rails (8) are slidably connected with a sliding frame (9). The carrier rack (10) is arranged between the two sliding frames (9) and is detachably connected to the sliding frame (9).

6. The VOC purification equipment for the color coating industry based on a new catalytic technology according to claim 5, characterized in that, The carrier rack (10) is a honeycomb carrier fixing rack.

7. The VOC purification equipment for the color coating industry based on a new catalytic technology according to claim 5, characterized in that, The inner wall of the reaction exhaust chamber (6) is connected with a heat exchanger (11) attached to the sliding frame (9).

8. A VOC purification device for the color coating industry based on a new catalytic technology according to claim 1, characterized in that, The composite metal oxide is composed of 30%-50% titanium dioxide, 30%-50% aluminum oxide, and 10%-20% cerium oxide by mass fraction.

9. The VOC purification equipment for the color coating industry based on the new catalytic technology according to claim 1, wherein For the oxides of manganese, cobalt, and copper, the loading amount of manganese dioxide is 5%-10% of the mass of the carrier, the loading amount of cobalt tetroxide is 3%-8% of the mass of the carrier, and the loading amount of copper oxide is 2%-6% of the mass of the carrier.

10. The VOC purification equipment for the color coating industry based on a new catalytic technology according to claim 1, characterized in that, For the oxides of cerium, zirconium, and lanthanum, the additional loading amount of cerium dioxide is 1%-3% of the mass of the carrier, the loading amount of zirconium dioxide is 1%-3% of the mass of the carrier, and the loading amount of lanthanum oxide is 0.5%-2% of the mass of the carrier; For the oxides of nickel, iron, and chromium, the loading amount of nickel oxide is 1%-3% of the mass of the carrier, the loading amount of ferric oxide is 0.5%-2% of the mass of the carrier, and the loading amount of chromium sesquioxide is 0.5%-2% of the mass of the carrier; The oxides of molybdenum and tungsten, wherein the loading amount of molybdenum trioxide is 0.5%-2% of the mass of the carrier, and the loading amount of tungsten trioxide is 0.5%-2% of the mass of the carrier.

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