Zeolite adsorption catalysis module for treating VOCs waste gas and preparation method

Abstract

The invention relates to a zeolite adsorption catalysis module for treating VOCs waste gas and a preparation method, and belongs to the field of waste gas treatment. According to the zeolite adsorption catalysis module, glass fibers serve as a carrier, active components are loaded on ZSM-5 zeolite through a step-by-step impregnation technology and a step-by-step roasting technology, and a catalysis system with a synergistic effect is formed. The preparation method comprises a step-by-step impregnation process to avoid crystal form competition and rare earth wrapping, a modular preparation process parameter system ensures uniform dispersion and synergistic effect of the active components, and the synergistic effect mechanism of the active components significantly improves the adsorption and catalytic performance. Compared with other combinations, the quaternary system has better catalytic conversion rate and cycling stability, and proportion optimization is crucial to the catalytic effect. According to the present invention, the efficient treatment on the VOCs-containing waste gas is achieved, and the method has advantages of high adsorption rate, short desorption time, strong low-temperature catalytic activity, good stability and the like, and can be widely used for the waste gas treatment in a plurality of industries.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, specifically a zeolite adsorption catalytic module for treating VOCs waste gas and its preparation method. Background Technology

[0002] Volatile organic compounds (VOCs) are a major source of air pollution, primarily originating from industrial production, transportation, and daily life. VOCs have a wide range of sources; industries such as petrochemicals, coating, printing, electronics, and pharmaceuticals all generate large amounts of VOCs waste gas.

[0003] Currently, there are numerous methods for treating VOCs waste gas, mainly including adsorption, catalytic oxidation, photocatalysis, and biological methods. Among them, adsorption has become one of the main methods for VOCs treatment due to its advantages such as simple operation, low cost, and good treatment effect. Adsorption is a method that separates VOCs from waste gas through adsorption on the surface of an adsorbent. Its core is the selection of highly efficient adsorbents, such as activated carbon, zeolite, and molecular sieves. Activated carbon has advantages such as large specific surface area and strong adsorption capacity, but its performance deteriorates when treating waste gas with high humidity, and the regeneration process is complex. Zeolite has a regular pore structure and high specific surface area, exhibiting good adsorption performance for VOCs, especially showing excellent adsorption selectivity under high humidity conditions.

[0004] Zeolite rotor adsorption concentration technology is a highly efficient VOCs treatment technology that purifies and concentrates waste gas through adsorption modules in a zeolite rotor. The zeolite rotor consists of an adsorption zone, a desorption zone, and a cooling zone: when waste gas passes through the adsorption zone, VOCs are adsorbed onto the zeolite surface, and the purified gas can be discharged; in the desorption zone, hot air or other hot gases desorb the adsorbed VOCs, and the concentrated VOCs waste gas is then treated by subsequent processes (such as catalytic oxidation); the cooling zone is used to cool the gas and restore the adsorption performance of the zeolite. The adsorption module is the core component of the zeolite rotor, and its performance directly determines the overall VOCs treatment effect of the system. However, traditional zeolite adsorption modules mainly use zeolite as the adsorbent, and have shortcomings in terms of adsorption capacity, desorption efficiency, and desorption time. For example, they suffer from poor adsorption selectivity, incomplete and time-consuming desorption, and high energy consumption due to the need for high-temperature regeneration.

[0005] Therefore, developing an adsorption module that combines efficient adsorption-desorption functions, low-temperature catalytic activity, and short desorption time is of great practical significance. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a zeolite adsorption catalytic module for treating VOCs waste gas and its preparation method. The technical solution is as follows:

[0007] In a first aspect, a zeolite adsorption catalytic module for treating VOCs waste gas includes:

[0008] Carrier: Glass fiber substrate;

[0009] Adsorption catalyst layer: zeolite supported on a support, and active components lanthanum oxide, neodymium oxide, manganese oxide and copper oxide dispersed in the zeolite;

[0010] The active component accounts for 1-15 wt% of the total mass of the adsorption catalyst layer and satisfies the following conditions:

[0011] The ratio of copper oxide to manganese oxide is 1:0.8~2;

[0012] The ratio of neodymium oxide to lanthanum oxide is 0.1 to 1:1.

[0013] Furthermore, the glass fiber substrate is glass fiber paper or glass fiber honeycomb material.

[0014] Furthermore, in the active component:

[0015] Manganese oxide exists in α-MnO2, β-MnO2, or γ-MnOOH crystal forms;

[0016] Copper oxide exists in the form of CuO or Cu2O.

[0017] Secondly, the preparation method of the zeolite adsorption catalytic module for treating VOCs waste gas includes the following steps:

[0018] Step 1: Slurry preparation

[0019] Zeolite powder, additives, manganese nitrate, and copper nitrate are added to silica sol and stirred to obtain a slurry.

[0020] Step 2: Substrate impregnation and pre-baking

[0021] A glass fiber substrate is impregnated in a slurry, dried, and then calcined to obtain a calcined module;

[0022] Step 3: Rare earth impregnation

[0023] The calcination module obtained in step 2 was immersed in a mixed solution of neodymium nitrate and lanthanum nitrate for treatment, and then dried after treatment;

[0024] Step 4, Step-by-step roasting

[0025] Segmented roasting is employed;

[0026] Step 5: Cooling down

[0027] Cooling the temperature to room temperature yields the zeolite adsorption catalytic module.

[0028] Further, in step 1, the mass ratio of zeolite powder to the total mass of manganese nitrate and copper nitrate is 5~15:1; the mass ratio of manganese nitrate to copper nitrate is 1:0.8~2; the mass ratio of zeolite powder to silica sol is 1:10~30; and the mass ratio of zeolite powder to additives is 100:0.4~2.

[0029] The zeolite powder is made of ZSM-5 zeolite;

[0030] The additive is water glass or cellulose.

[0031] Furthermore, in step 2, the drying temperature is 100~150℃, and the drying time is 0.5~1.5h;

[0032] The roasting temperature is 400~450℃ and the roasting time is 1.5~3h.

[0033] Furthermore, in step 3, the drying temperature is 100~130℃, and the drying time is 0.5~1.5h;

[0034] The calcination module is immersed in a mixed solution of neodymium nitrate and lanthanum nitrate at a temperature of 30~45℃ for a time of 0.5~1h.

[0035] In a mixed solution of neodymium nitrate and lanthanum nitrate, the mass ratio of neodymium nitrate to lanthanum nitrate is 0.1 to 1:1.

[0036] In step 4, the product is calcined in stages at a heating rate of 50~150℃ / h:

[0037] Keep warm at 200℃ for 1-3 hours, then at 400℃ for 1-3 hours, and finally at 600℃ for 1-3 hours.

[0038] In step 5, the cooling rate shall not exceed 400℃ / h.

[0039] Thirdly, a volatile organic compound treatment system uses the aforementioned zeolite adsorption catalysis module as the core component of the zeolite rotor.

[0040] Furthermore, hot air at 180~200℃ is used for regeneration during the desorption stage, and the desorption time is ≤5min.

[0041] Fourthly, a method for treating VOCs waste gas includes the following steps:

[0042] Adsorption stage: VOCs waste gas passes through the zeolite adsorption catalytic module, with an adsorption temperature ≤40℃;

[0043] Desorption stage: Hot air at 180~200℃ is introduced for desorption, while VOCs waste gas is catalytically oxidized at the same time.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] 1. High-efficiency adsorption-desorption: It has a large adsorption capacity and fast speed for a variety of VOCs, and a high desorption efficiency and short desorption time of no more than 5 minutes, which reduces energy consumption and treatment costs.

[0046] 2. Low-temperature catalytic oxidation: Some VOCs can be catalytically oxidized at a low temperature of 180~200℃, with a conversion rate of over 50%, which improves the system's ability to treat VOCs.

[0047] 3. Significant synergistic effect: The synergistic effect of lanthanum oxide, neodymium oxide, manganese oxide and copper oxide makes the performance of the zeolite adsorption catalytic module far exceed that of zeolite adsorption materials loaded with a single active component.

[0048] 4. High performance stability: The quaternary composite system has excellent thermal stability and anti-poisoning ability, and the performance degradation rate after cyclic use is low (the retention rate is > 95% after 200 cycles).

[0049] 5. Application prospects: It can be widely used in the treatment of VOCs waste gas containing benzene, toluene, xylene, esters and other compounds in multiple industries, with good economic and environmental benefits. Detailed Implementation

[0050] The present invention will be described in detail below with reference to specific embodiments. These embodiments are merely some, not all, implementations of the present invention. All other implementations obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0051] Example 1

[0052] This invention aims to provide a CuO-MnO2-La2O3-Nd2O3 composite zeolite adsorption catalytic module containing lanthanum oxide, neodymium oxide, manganese oxide, copper oxide, and ZSM-5 zeolite. This module possesses adsorption and low-temperature catalytic oxidation characteristics and serves as a key component of the zeolite rotor, enabling efficient treatment of VOC-containing waste gas. This zeolite adsorption catalytic module not only efficiently adsorbs and desorbs VOCs but also catalytically oxidizes some VOCs at relatively low temperatures, with a desorption time not exceeding 10 minutes and, after optimization, not exceeding 5 minutes. By performing catalytic oxidation simultaneously with adsorption purification, it significantly improves the system's efficiency in treating VOCs.

[0053] 1. Step-by-step impregnation process

[0054] Avoiding crystal form competition: Studies have found that CuO / MnO x Stable crystal forms (α-MnO2, CuO) need to be individually calcined at 400-450℃. Studies have found that if rare earth ions (La...) 3+ / Nd 3+ Simultaneous impregnation will result in a Mn / Cu lattice distortion rate of >20%, which will seriously affect the performance and synergistic effect of the active components.

[0055] To prevent rare earth encapsulation: Preloading rare earth elements will cover the zeolite channels, causing a 30% decrease in BET specific surface area and hindering the exposure of active sites. This reduces adsorption and catalytic efficiency.

[0056] Synergistic effect of stepped roasting: 600℃ roasting promotes the migration of La2O3 / Nd2O3 to the Mn-Cu interface, forming a 2-5nm rare earth shell protective structure with a specific surface area retention rate of >95%.

[0057] To avoid competition for crystal forms, CuO / MnO x A stable crystal form is formed by separate calcination at 400-450℃. In addition, the above problems can be effectively solved by using a stepwise impregnation process, first impregnating manganese nitrate and copper nitrate, and then impregnating neodymium nitrate and lanthanum nitrate.

[0058] In the subsequent stepped calcination process, calcination at 600℃ promotes the migration of La2O3 / Nd2O3 to the Mn-Cu interface, forming a 2-5nm rare earth shell protective structure, which makes the specific surface area retention rate >95%, thereby ensuring the good dispersion of active components and the full play of synergistic effects.

[0059] 2. Modular preparation process parameter system

[0060] The mixture of ZSM-5 zeolite, manganese nitrate, and copper nitrate was prepared.

[0061] ZSM-5 zeolite powder, water glass and other additives, manganese nitrate, and copper nitrate are added sequentially to silica sol and stirred while maintaining the temperature at 30-40℃ to obtain a slurry. The mass ratio of ZSM-5 zeolite powder to manganese nitrate + copper nitrate is 5-15:1. The mass ratio of manganese nitrate to copper nitrate is 1:0.8-2. The mass ratio of ZSM-5 zeolite powder to silica sol is 1:10-30. The mass ratio of ZSM-5 zeolite powder to additives is 100:0.4-2. (Additives such as water glass act as a binder, and cellulose acts as a pore-forming agent to enhance the adhesion between the zeolite and the substrate and optimize the pore structure.)

[0062] Preparation of the adsorption module: A glass fiber paper or glass fiber honeycomb base module is used as the substrate. The base module is immersed in the above-mentioned slurry, then dried and calcined to obtain the adsorption module. The drying temperature is 100~150℃, and the time is 0.5~1.5h. The calcination temperature is 400~450℃, and the time is 1.5~3h.

[0063] The adsorption module is impregnated with neodymium nitrate and lanthanum nitrate. The prepared adsorption module was immersed in a solution of neodymium nitrate and lanthanum nitrate. The mass fraction of the neodymium nitrate and lanthanum nitrate solution was 5-30%. The immersion time was 0.5-1 h, and the temperature was maintained at 30-45 °C. The module was then dried to obtain the immersed module. The mass ratio of neodymium nitrate to lanthanum nitrate in the solution was 0.1-1:1. The drying temperature was 100-130 °C, and the drying time was 0.5-1.5 h.

[0064] Calcination. The impregnated module is calcined. The temperature is 200℃ for 1-3 hours, 400℃ for 1-3 hours, and 600℃ for 1-3 hours. The heating rate is 50-150℃ / h. The zeolite adsorption catalytic module is finally obtained.

[0065] Structure and Performance of the Zeolite Adsorption Catalytic Module: The zeolite adsorption catalytic module serves as the core adsorption and desorption component of the zeolite rotor. During the adsorption stage, leveraging the characteristics of ZSM-5 zeolite and the synergistic effect of the four active components, it exhibits excellent adsorption performance for various VOCs. During the desorption stage, when the hot air temperature is between 180 and 200°C, the adsorbed VOCs can be effectively desorbed within 5 minutes. Simultaneously, at this temperature, the zeolite and its supported lanthanum oxide, neodymium oxide, manganese oxide, and copper oxide can catalytically oxidize some of the desorbed VOCs, achieving a VOCs conversion rate of over 50%.

[0066] Synergistic effect of active components: Neodymium oxide possesses excellent oxygen storage capacity, providing and storing oxygen species in catalytic reactions to promote the smooth progress of redox reactions. Manganese oxide exhibits high catalytic activity at relatively low temperatures, effectively catalyzing the oxidation of some VOCs. Copper oxide has good electron conductivity, accelerating electron transfer and enhancing the overall activity of the catalytic system. The synergistic effect of these three active components allows the loaded zeolite to efficiently adsorb and rapidly desorb VOCs during the adsorption-desorption process, while also catalyzing the oxidation of some VOCs at low temperatures, significantly improving the system's VOCs treatment efficiency.

[0067] The additives can be water glass (as a binder) or cellulose (as a pore-forming agent).

[0068] Table 1 Modular manufacturing process parameter system

[0069]

[0070] 3. Performance characteristics of zeolite adsorption catalysis module

[0071] (1) Technological characteristics

[0072] Adsorption stage: The porous structure of ZSM-5 zeolite works synergistically with the active components to achieve an adsorption rate of ≥92% for VOCs such as benzene, toluene, xylene, and ethyl acetate.

[0073] Desorption-catalysis stage: Under hot air conditions of 180~200℃, the desorption time is ≤5min, and the VOCs catalytic conversion rate is ≥50% (10-15% higher than that of ternary systems).

[0074] (2) Synergistic mechanism of active components

[0075] (2.1) The role of neodymium oxide

[0076] Active components: lanthanum oxide, neodymium oxide, manganese oxide, and copper oxide.

[0077] Adsorbent: ZSM-5 zeolite.

[0078] Carrier: Glass fiber

[0079] In the catalytic process, neodymium oxide can provide additional active sites, promoting the adsorption and activation of VOCs. The introduction of neodymium oxide can improve the thermal stability of the catalyst, enabling it to maintain good catalytic performance during high-temperature regeneration.

[0080] (2.2) The role of manganese oxide

[0081] Low-temperature activity: The active sites of manganese oxide can adsorb VOC molecules and activate them into intermediate products, thereby accelerating the oxidation reaction.

[0082] Anti-poisoning ability: The multivalent state characteristics of manganese oxide make it exhibit better stability when treating complex VOCs waste gases containing sulfur and chlorine.

[0083] (2.3) The role of copper oxide

[0084] High oxidation activity: Copper oxide has high oxidation activity and can effectively catalyze the oxidation reaction of VOCs.

[0085] Reactive oxygen species formation: The active sites of copper oxide can adsorb oxygen and form reactive oxygen species (such as superoxide radicals and hydroxyl radicals), which can further oxidize VOCs.

[0086] Low-temperature catalytic performance: The introduction of copper oxide can improve the low-temperature activity and selectivity of the catalyst.

[0087] (2.4) The role of lanthanum oxide

[0088] Inhibiting carbon deposition and improving stability. Lanthanum oxide can regulate the acidity and alkalinity of the catalyst surface, reducing excessive adsorption and carbon deposition of hydrocarbon species on the surface, thereby improving the thermal stability and service life of the catalyst.

[0089] (2.5) Quadrivalent synergistic mechanism

[0090] ① Synergistic electronic structure: The introduction of neodymium oxide can regulate the electronic structure of manganese oxide and copper oxide, enhance the formation of oxygen vacancies and oxygen migration ability, thereby improving the overall activity of the catalyst.

[0091] ② Synergistic Complementary Active Sites: The active sites of manganese oxide and copper oxide can work synergistically to promote the adsorption and activation of VOCs. The multivalent state characteristics of manganese oxide combined with the high oxidizing activity of copper oxide can significantly improve the oxidation efficiency of VOCs. Manganese oxide provides low-temperature active sites, copper oxide supplements the oxidizing capacity, and lanthanum oxide stabilizes intermediate products.

[0092] ③ Improved thermal stability: The introduction of neodymium oxide can improve the thermal stability of the catalyst, enabling it to maintain good catalytic performance during high-temperature regeneration. The lanthanum oxide-neodymium oxide interface forms a protective shell, inhibiting the sintering of the active components.

[0093] ④ Enhanced resistance to poisoning: The introduction of neodymium oxide can improve the catalyst's resistance to poisoning, making it exhibit better stability when treating complex VOCs waste gases containing sulfur and chlorine.

[0094] 4. Comparative test results:

[0095] 4.1 Quantitative Comparison of Catalytic Performance

[0096] Table 2 Catalytic oxidation performance of toluene with different combinations of active components

[0097]

[0098] Table 3 Advantages of the quaternary system for treating typical VOCs

[0099]

[0100] 4.2. Essential Analysis of the Collaboration Mechanism

[0101] Table 4 Effect of component absence on catalytic performance

[0102]

[0103] 4.3 Optimization of Formulation and Industrial Application Parameters

[0104] The scientific boundaries of active ingredient ratios

[0105] ①CuO:MnO x=1:0.8-1.2 (Optimal 1:1.2)

[0106] When the CuO ratio is too high (1:0.5): Mn 3+ / Mn 4+ The recycling efficiency decreased, and the xylene conversion rate was less than 45%.

[0107] When MnO x The ratio is too high (1:1.5): Cu + / Cu 2+ Electron transfer is hindered, and the toluene conversion rate is <40%.

[0108] ②Nd₂O₃:La₂O₃ = 0.5-1:1 (optimal 0.5:1)

[0109] When the proportion of La2O3 is too low (0.1:1), the stability of the Mn-Cu interface decreases, and the conversion rate retention rate is less than 85% after 200 cycles.

[0110] When the Nd2O3 ratio is too low (0.1:1), the oxygen storage capacity decreases by 50% and the VOCs mineralization rate decreases by 10%.

[0111] La2O3-Nd2O3-CuO-MnO x The quaternary system achieves optimal processing results through the following synergistic effects:

[0112] Benzene series treatment: La / Nd activates the benzene ring + Mn cleaves the CH bond + Cu generates ·OH → conversion rate 52-62% (10-14% higher than ternary compounds).

[0113] Ester degradation: Mn attacks C=O bonds + Cu oxidizes aldehydes + Nd provides oxygen → conversion rate 55% (15% higher than ternary esters).

[0114] Industrial compatibility: The sulfur resistance / stability of quaternary synergy is more than 40% higher than that of ternary synergy.

[0115] Experiments show that reducing any one active component leads to a 10-33% decrease in conversion rate, which cannot be compensated for by adjusting other components. The quaternary combination is the only solution to achieve the technical goal of "low-temperature, high-efficiency catalytic oxidation".

[0116] 5. Technological advantages:

[0117] 5.1 Synergistic catalytic effect

[0118] The composite system of lanthanum oxide, neodymium oxide, manganese oxide and copper oxide significantly improves the activity and selectivity of the catalyst through synergistic effects, and can partially oxidize VOCs at lower temperatures.

[0119] 5.2 Adsorption-Desorption Function

[0120] The porous structure and high specific surface area of ​​ZSM-5 zeolite provide good dispersibility and stability for the active components, while also possessing efficient adsorption and desorption capabilities.

[0121] 5.3 Energy-saving and efficient

[0122] During the regeneration process, some VOCs are catalytically oxidized, reducing regeneration energy consumption and improving the overall VOCs treatment efficiency of the system.

[0123] 5.4 Low performance degradation rate

[0124] The quaternary system exhibits higher cycle stability (96%) than the comparative examples lacking any one component (see Examples 6-8).

[0125] 6. Correlation between formulation optimization and catalytic effect

[0126] 6.1 Basis for Optimization of Active Component Ratio

[0127] Comparative experiments (Table 1-4) confirmed the quaternary system (La2O3-Nd2O3-CuO-MnO) x The synergistic effect of ) must strictly meet the following ratio:

[0128] CuO:MnO x = 1:0.8~1.2 (optimal 1:1.2):

[0129] When the CuO ratio is too high (e.g., 1:0.5), Mn 3+ / Mn 4+ Reduced redox cycle efficiency leads to decreased low-temperature activity (e.g., xylene conversion rate <45%).

[0130] When MnO x If the ratio is too high (e.g., 1:1.5), Cu + / Cu 2+ Electron transfer is hindered, resulting in insufficient generation of ·OH free radicals (e.g., toluene conversion rate <40%).

[0131] Nd₂O₃:La₂O₃ = 0.5~1:1 (optimal 0.5:1):

[0132] When the La2O3 ratio is too low (e.g., 0.1:1), the stability of the Mn-Cu interface decreases (XPS shows Mn...). 4+ / Mn 3+ The ratio decreased by 30%, which led to a decrease in cycle stability (conversion rate retention rate <85% after 200 cycles).

[0133] When the Nd2O3 ratio is too low (e.g., 0.1:1), the oxygen storage capacity is insufficient (the oxygen supply rate of O2-TPD decreases by 50%), and the VOCs mineralization rate decreases by 10%.

[0134] 6.2 Consequences of Proportion Deviation

[0135] If the above range is exceeded, and the cycle stability deteriorates significantly (conversion rate retention rate ≤80% after 200 cycles).

[0136] Example 2

[0137] 1. Slurry preparation:

[0138] Take 10.0 kg of ZSM-5 zeolite powder and 0.1 kg of additive (water glass) and add them to 150 L of silica sol. Stir at 35℃, then add 0.83 kg of manganese nitrate and 0.67 kg of copper nitrate in sequence. Continue stirring for 1 hour and keep the temperature at 35±5℃.

[0139] 2. Impregnation and drying / calcination of the adsorption module substrate:

[0140] Cut the fiberglass honeycomb material into 150mm×150mm×50mm blocks and immerse them completely in the prepared slurry to ensure full saturation.

[0141] Soak for 1 hour at a temperature of 35±5℃.

[0142] Remove and drain off excess liquid.

[0143] Dry at 110℃ for 1 h.

[0144] Calcination at 400℃ for 2 hours. Heating rate: 100℃ / h.

[0145] 3. Module impregnation with neodymium nitrate:

[0146] Prepare a 20% solution of neodymium nitrate and lanthanum nitrate (neodymium nitrate: lanthanum nitrate = 0.5:1).

[0147] The module after calcination in step 2 was immersed in a solution of neodymium nitrate and lanthanum nitrate at 40°C for 0.75 h.

[0148] Remove and drain off any excess solution.

[0149] Dry at 110℃ for 1 h.

[0150] 4. Step-roasting:

[0151] The dried modules are then subjected to a stepped firing process.

[0152] The temperature was increased to 200℃ at a rate of 100℃ / h and held for 2 hours.

[0153] Continue to increase the temperature to 400℃ at a rate of 100℃ / h, and hold for 2 hours.

[0154] Finally, the temperature is increased to 600℃ at a rate of 100℃ / h and held for 2 hours.

[0155] 5. Cooling down:

[0156] Naturally cool to room temperature. Cooling rate: 200~300℃ / h.

[0157] 6. Performance Testing:

[0158] The prepared adsorption module is assembled into the zeolite rotor system as the core component.

[0159] Adsorption stage: Waste gas containing VOCs such as toluene and xylene is introduced at a concentration of 300 ppm, a flow rate of 1000 m³ / h, an adsorption temperature of 25℃, and an adsorption time of 1 h.

[0160] Desorption stage: Hot air at 180℃ is introduced for desorption, with a flow rate of 100 m³ / h and a desorption time of 3 min.

[0161] The concentrations of VOCs at the adsorption inlet and outlet and the desorption outlet were monitored online using a gas chromatograph (GC).

[0162] Test results: The adsorption module achieved an adsorption rate of 92% for mixed VOCs, and a catalytic conversion rate of 58% for VOCs during the desorption process at 180℃.

[0163] Example 3

[0164] 1. Slurry preparation:

[0165] Take 10.0 kg of ZSM-5 zeolite powder, 0.06 kg of water glass and 0.05 kg of cellulose and add them to 200 L of silica sol.

[0166] Stir at 30°C.

[0167] Add 0.75 kg of manganese nitrate and 1.00 kg of copper nitrate in sequence.

[0168] Continue stirring for 1.5 hours, maintaining a temperature of 30±5℃.

[0169] 2. Impregnation and drying / calcination of the adsorption module substrate:

[0170] Cut the fiberglass honeycomb material into 150mm×150mm×50mm blocks and immerse them completely in the prepared slurry to ensure full saturation.

[0171] Soak for 1 hour, maintaining a temperature of 30±5℃.

[0172] Remove and drain off excess liquid.

[0173] Dry at 110℃ for 0.5h.

[0174] Calcination at 425℃ for 3 hours. Heating rate: 150℃ / h.

[0175] 3. Module impregnation with neodymium nitrate and lanthanum nitrate:

[0176] Prepare a 10% solution of neodymium nitrate and lanthanum nitrate. The ratio of neodymium nitrate to lanthanum nitrate is 0.8:1.

[0177] Soak for 1 hour at 30°C.

[0178] Dry at 110℃ for 1 h.

[0179] 4. Roasting:

[0180] Stepped roasting process:

[0181] Heat to 200℃ at a rate of 50℃ / h and hold for 3 hours.

[0182] Heat to 400℃ at a rate of 50℃ / h and hold for 3 hours.

[0183] Heat to 600℃ at a rate of 50℃ / h and hold for 1 hour.

[0184] 5. Cooling down:

[0185] Naturally cool to room temperature. Cooling rate: 250~350℃ / h.

[0186] 6. Performance Testing:

[0187] Introduce benzene-containing waste gas at a concentration of 300 ppm. Adsorption: 1000 m³ / h, 25℃, 1h; Desorption: 180℃, 150 m³ / h, 3min.

[0188] Test results: Adsorption rate 92%, VOCs catalytic conversion rate 52%.

[0189] Example 4

[0190] 1. Slurry preparation:

[0191] Take 10.0 kg of ZSM-5 zeolite powder, 0.20 kg of water glass and 0.05 kg of cellulose and add them to 250 L of silica sol.

[0192] Stir at 40°C.

[0193] Add 1.0 kg of manganese nitrate and 0.8 kg of copper nitrate in sequence.

[0194] Continue stirring for 0.5 h, maintaining a temperature of 40±5℃.

[0195] 2. Impregnation and drying / calcination of the adsorption module substrate:

[0196] Cut the fiberglass honeycomb material into 150mm×150mm×50mm blocks and immerse them completely in the prepared slurry to ensure full saturation.

[0197] Soak for 1 hour at a temperature of 40±5℃.

[0198] Remove and drain off excess liquid.

[0199] Dry at 110℃ for 1 h.

[0200] Calcination at 400℃ for 2.5 hours. Heating rate: 100℃ / h.

[0201] 3. Module impregnation with neodymium nitrate:

[0202] Prepare a 25% solution of neodymium nitrate and lanthanum nitrate. The ratio of neodymium nitrate to lanthanum nitrate is 0.1:1.

[0203] Soak for 0.5 h at 45℃.

[0204] Dry at 110℃ for 1 h.

[0205] 4. Roasting:

[0206] Stepped roasting process:

[0207] Heating rate: 150℃ / h to 200℃, hold for 1 h.

[0208] Heating rate 150℃ / h to 400℃, hold for 1 h.

[0209] Heating rate 150℃ / h to 600℃, hold for 3 h.

[0210] Natural cooling.

[0211] 5. Cooling down:

[0212] Naturally cool to room temperature. Cooling rate: 200~300℃ / h.

[0213] 6. Performance Testing:

[0214] Waste gas containing xylene at a concentration of 500 ppm was introduced. Adsorption: 1000 m³ / h, 25℃, 1h; Desorption: 190℃, 80 m³ / h, 4min.

[0215] Test results: Adsorption rate 95%, VOCs catalytic conversion rate 62%.

[0216] Example 5

[0217] 1. Slurry preparation:

[0218] Take 10.0 kg of ZSM-5 zeolite powder and 0.20 kg of sodium silicate additive and add them to 300 L of silica sol.

[0219] Stir at 40°C.

[0220] Add 0.8 kg of manganese nitrate and 0.8 kg of copper nitrate in sequence.

[0221] Continue stirring for 0.5 h, maintaining a temperature of 40±5℃.

[0222] 2. Impregnation and drying / calcination of the adsorption module substrate:

[0223] Cut the fiberglass honeycomb material into 150mm×150mm×50mm blocks and immerse them completely in the prepared slurry to ensure full saturation.

[0224] Soak for 1 hour at a temperature of 40±5℃.

[0225] Remove and drain off excess liquid.

[0226] Dry at 110℃ for 1.5 h.

[0227] Calcination at 400℃ for 2 hours. Heating rate: 100℃ / h.

[0228] 3. Module impregnation with neodymium nitrate and lanthanum nitrate:

[0229] Prepare a 25% solution of neodymium nitrate and lanthanum nitrate. The ratio of neodymium nitrate to lanthanum nitrate is 0.5:1.

[0230] Soak for 0.5 h at 45℃.

[0231] Dry at 110℃ for 1 h.

[0232] 4. Roasting:

[0233] Stepped roasting process:

[0234] Heating rate: 150℃ / h to 200℃, hold for 1 h.

[0235] Heating rate 150℃ / h to 400℃, hold for 1 h.

[0236] Heating rate 150℃ / h to 600℃, hold for 3 h.

[0237] 5. Cooling down:

[0238] Naturally cool to room temperature. Cooling rate: 350~380℃ / h.

[0239] 6. Performance Testing:

[0240] Waste gas containing ethyl acetate was introduced at a concentration of 500 ppm. Adsorption: 1000 m³ / h, 25℃, 1h; Desorption: 195℃, 80 m³ / h, 4min.

[0241] Test results: Adsorption rate 96%, VOCs catalytic conversion rate 55%.

[0242] Example 6 (Lanium oxide only, no neodymium oxide)

[0243] 1. Slurry preparation

[0244] Take 10.0 kg of ZSM-5 zeolite powder and 0.15 kg of water glass and add them to 200 L of silica sol. Stir at 35 ℃. Then add 0.83 kg of manganese nitrate and 0.67 kg of copper nitrate in sequence, and continue stirring for 1 h while maintaining the temperature at 35±5 ℃.

[0245] 2. Impregnation and drying / calcination of the adsorption module substrate

[0246] A 150 mm × 150 mm × 50 mm glass fiber honeycomb material was immersed in the slurry and drained after 1 hour. It was then dried at 110℃ for 1 hour and calcined at 400℃ for 2 hours (heating rate 100℃ / h).

[0247] 3. Module impregnated with lanthanum nitrate

[0248] Prepare a 20% lanthanum nitrate solution (Nd-free). Immerse the module in the solution at 40 °C for 0.75 h; then dry at 110 °C for 1 h.

[0249] 4. Step-roasting

[0250] 100 ℃ / h → 200 ℃ (2 h) → 400 ℃ (2 h) → 600 ℃ (2 h),

[0251] 5. Cooling down:

[0252] Naturally cool to room temperature. Cooling rate: 200~300℃ / h.

[0253] 6. Performance Testing

[0254] Adsorption: 300 ppm toluene + xylene mixed VOCs, 1000 m³ / h, 25 ℃, 1 h.

[0255] Desorption: 100 m³ / h of 180 ℃ hot air for 3 min.

[0256] Results: Adsorption rate 90%, catalytic conversion rate 48%.

[0257] Example 7 (Neodyne oxide only, no lanthanum oxide)

[0258] The slurry and primary roasting parameters are exactly the same as in Example 6.

[0259] Single rare earth impregnation

[0260] Prepare a 20% neodymium nitrate solution (without La), and follow the same procedures as in Example 6.

[0261] The roasting and cooling processes are the same as in Example 6.

[0262] Performance testing

[0263] The test conditions were the same as in Example 6.

[0264] Results: Adsorption rate 89%, catalytic conversion rate 46%.

[0265] Example 8 (without lanthanum oxide and neodymium oxide)

[0266] The slurry and primary roasting parameters remain the same as in Example 6.

[0267] Without the rare earth impregnation step, the module undergoes a second step roasting directly after the first roasting.

[0268] Performance testing

[0269] The test conditions were the same as in Example 6.

[0270] Results: Adsorption rate 87%, catalytic conversion rate 38%.

[0271] Example 9

[0272] The slurry and the first firing were the same as in Example 2.

[0273] The concentration of the rare earth impregnation solution was 10%, the La:Nd molar ratio was kept at 1:0.5, and the rest of the operation remained unchanged.

[0274] Performance testing

[0275] The test conditions were the same as in Example 6.

[0276] Results: Adsorption rate 91%, catalytic conversion rate 52%.

[0277] In the above embodiments, the active component ratio and stepwise impregnation process of the present invention are designed based on a synergistic mechanism. Experiments show that the absence of any component or the excess of its ratio will lead to a decrease in catalytic efficiency of >10%, which cannot be compensated by process adjustment.

[0278] In the above embodiments, the density of the glass fiber substrate is 200 g / L, and the mass of the module with a size of 150×150×50 mm is 2.0±0.01 kg.

[0279] Furthermore, it should be understood that those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A zeolite adsorption catalytic module for treating VOCs waste gas, characterized in that, include: Carrier: Glass fiber substrate; Adsorption catalyst layer: zeolite supported on a support, and active components lanthanum oxide, neodymium oxide, manganese oxide and copper oxide dispersed in the zeolite; The active component accounts for 1-15 wt% of the total mass of the adsorption catalyst layer and satisfies the following conditions: The ratio of copper oxide to manganese oxide is 1:0.8~2; The ratio of neodymium oxide to lanthanum oxide is 0.1 to 1:

1.

2. The zeolite adsorption catalytic module for treating VOCs waste gas according to claim 1, characterized in that: The glass fiber substrate is glass fiber paper or glass fiber honeycomb material.

3. The zeolite adsorption catalytic module for treating VOCs waste gas according to claim 1, characterized in that: In the active component: Manganese oxide exists in α-MnO2, β-MnO2, or γ-MnOOH crystal forms; Copper oxide exists in the form of CuO or Cu2O.

4. A method for preparing a zeolite adsorption catalytic module for treating VOCs waste gas as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Slurry preparation Zeolite powder, additives, manganese nitrate, and copper nitrate are added to silica sol and stirred to obtain a slurry. Step 2: Substrate impregnation and pre-baking A glass fiber substrate is impregnated in a slurry, dried, and then calcined to obtain a calcined module; Step 3: Rare earth impregnation The calcination module obtained in step 2 was immersed in a mixed solution of neodymium nitrate and lanthanum nitrate for treatment, and then dried after treatment; Step 4, Step-by-step roasting Segmented roasting is employed; Step 5: Cooling down Cooling the temperature to room temperature yields the zeolite adsorption catalytic module.

5. The preparation method according to claim 4, characterized in that: In step 1, the mass ratio of zeolite powder to the total mass of manganese nitrate and copper nitrate is 5~15:1; the mass ratio of manganese nitrate to copper nitrate is 1:0.8~2; the mass ratio of zeolite powder to silica sol is 1:10~30; and the mass ratio of zeolite powder to additives is 100:0.4~2. And / or, The zeolite powder is made of ZSM-5 zeolite; And / or, The additive is water glass or cellulose.

6. The preparation method according to claim 4, characterized in that: In step 2, the drying temperature is 100~150℃, and the drying time is 0.5~1.5h; And / or, The roasting temperature is 400~450℃ and the roasting time is 1.5~3h.

7. The preparation method according to claim 4, characterized in that: In step 3, the drying temperature is 100~130℃, and the drying time is 0.5~1.5h; And / or, The calcination module is immersed in a mixed solution of neodymium nitrate and lanthanum nitrate at a temperature of 30~45℃ for a time of 0.5~1h. And / or, In a mixed solution of neodymium nitrate and lanthanum nitrate, the mass ratio of neodymium nitrate to lanthanum nitrate is 0.1 to 1:

1. And / or, In step 4, the product is calcined in stages at a heating rate of 50~150℃ / h: Keep warm at 200℃ for 1-3 hours, then at 400℃ for 1-3 hours, and finally at 600℃ for 1-3 hours. And / or, In step 5, the cooling rate shall not exceed 400℃ / h.

8. A volatile organic compound (VOC) treatment system, characterized in that, The zeolite adsorption catalysis module as described in any one of claims 1-3 is used as the core component of the zeolite rotor.

9. The volatile organic compound treatment system according to claim 8, characterized in that, During the desorption stage, hot air at 180~200℃ is used for regeneration, and the desorption time is ≤5min.

10. A method for treating VOCs waste gas, characterized in that, Includes the following steps: Adsorption stage: VOCs waste gas passes through the zeolite adsorption catalytic module as described in any one of claims 1-3, with an adsorption temperature ≤40℃; Desorption stage: Hot air at 180~200℃ is introduced for desorption, while VOCs waste gas is catalytically oxidized at the same time.

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