Tail gas treatment method applied to thiophanate-methyl production

Abstract

The invention discloses a tail gas treatment method applied to thiophanate-methyl production, and belongs to the technical field of industrial tail gas treatment.The tail gas treatment method comprises the following steps that S1, collected tail gas is subjected to condensation treatment through an absorber to absorb and remove part of organic solvent and part of water, and primarily-treated tail gas is obtained; s2, carrying out adsorption and separation on the primarily treated tail gas by adopting a solid adsorbent to remove part of the organic solvent and most of water so as to obtain secondarily treated tail gas; and S3, carrying out catalytic oxidation treatment on the secondary treatment tail gas by adopting a catalytic oxidation method, and then discharging. The purification efficiency of the modified molecular sieve composite adsorbent on impurities such as hydrogen sulfide, hydrogen chloride and volatile compounds VOCs reaches 100% within 200 min, the tail gas treatment capacity per unit mass of the modified molecular sieve composite adsorbent and the catalyst used for catalytic oxidation is high, the effective purification time reaches up to 13200 min, the service life is long, and the purification effect is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial tail gas treatment, and in particular relates to a tail gas treatment method applied to the production of thiophanate-methyl. Background Art

[0002] Thiophanate-methyl is a thiourea-benzene type systemic fungicide with the characteristics of high efficiency, low toxicity, safe broad spectrum and strong systemicity. It is mainly used to control powdery mildew, sclerotinia, gray mold, anthrax, etc. of various economic crops such as rice, wheat, sweet potatoes, fruit trees, vegetables and cotton. The main raw material for the production of thiophanate-methyl is methyl chloroformate.

[0003] The main chemical reaction principle is: using methyl chloroformate, sodium thiocyanate and o-phenylenediamine as raw materials, according to a certain ratio, in the presence of solvent ethyl acetate and a catalyst, the synthesis reaction produces methyl thiophanate products. The general content is 95%, and the conversion rate of o-phenylenediamine is about 90%. In the process of synthetic production, methyl thiophanate will produce harmful tail gas, and the emission of tail gas will cause great pollution, which does not meet the current requirements of low-carbon environmental protection, energy conservation and emission reduction. In order to promote sustainable development, chemical companies need to put tail gas treatment in a key position in production, reasonably apply advanced tail gas treatment technology, and reduce the damage of tail gas to the environment. At present, the treatment technology of methyl thiophanate tail gas is becoming more and more diverse, but there are still certain technical deficiencies in the work of reagents, and there are many problems such as low purification efficiency and short service life of adsorbents and catalysts used for purification.

[0004] Based on this, we proposed a tail gas treatment method for methyl thiophanate production, hoping to solve the shortcomings of the existing technology. Summary of the invention

[0005] The purpose of the present invention is to provide a tail gas treatment method for thiophanate-methyl production in view of the existing problems.

[0006] The present invention is achieved through the following technical solutions:

[0007] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0008] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0009] S2, using a solid adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0010] S3. The secondary treated tail gas is subjected to catalytic oxidation treatment by catalytic oxidation and then discharged.

[0011] Preferably, the adsorbent is a modified molecular sieve composite adsorbent.

[0012] Preferably, the preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0013] (1) placing the ZSM-5 molecular sieve in a vacuum drying oven, drying it at 20-30°C for 3-5h, placing the dried ZSM-5 molecular sieve in a muffle furnace, heating it to 550°C at 3°C / min, high temperature roasting it for 4h, cooling it to room temperature, ultrasonically dispersing it in anhydrous ethanol, then adding trimethylchlorosilane, mixing and shaking it, condensing and refluxing it at 60-80°C for 4-20h, then cooling, filtering, washing it with anhydrous ethanol for 3 times, placing it in a vacuum drying oven, drying it at 20-30°C for 10-12h, and finally placing it in a muffle furnace and roasting it at 500-600°C for 4h to obtain a hydrophobic modified ZSM-5 molecular sieve;

[0014] (2) chitosan is added to acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, heated to 40-50° C., and then ammonium cerium nitrate and acrylamide aqueous solution are added in sequence. After constant temperature reaction for 3-4 hours, hydroquinone is added dropwise to terminate the reaction. After cooling to room temperature, the solution is neutralized with a 5% NaOH aqueous solution to precipitate the product. After filtering, the solution is immersed in anhydrous ethanol, and then chloroacetyl chloride is added and stirred. After stirring and reacting at 40-60° C. and 200-300 rpm for 2-3 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) is added, and after stirring at 300-400 rpm for 6-8 hours, the solution is filtered, washed with anhydrous ethanol for 3-5 times, and then placed in a vacuum drying oven and dried at 30-40° C. to obtain a modified molecular sieve composite adsorbent.

[0015] Preferably, the weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol in step (1) is 1 g: 6-20 mL;

[0016] The weight-to-volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.4-1.2 mL.

[0017] Preferably, the volume ratio of the 1% chitosan acetic acid solution to deionized water in step (2) is 1:0.2-0.3;

[0018] The mass ratio of the ammonium cerium nitrate to chitosan is 1:0.1-0.3;

[0019] The mass ratio of chitosan to acrylamide is 1:4-8;

[0020] The concentration of the acrylamide aqueous solution is 40%;

[0021] The amount of the hydroquinone added is 2 to 3 drops;

[0022] The mass ratio of chitosan to chloroacetyl chloride is 1:0.06-0.08;

[0023] The mass ratio of the chitosan to the hydrophobic modified ZSM-5 molecular sieve is 1:10-20.

[0024] Preferably, the catalyst used in the catalytic oxidation method described in step S3 is a supported metal oxide catalyst.

[0025] Preferably, the preparation of the supported metal oxide catalyst comprises the following steps:

[0026] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 20 to 30 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react in a water bath at 50 to 70° C. for 12 to 20 hours, add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water for 3 to 5 times, then wash with 50% ethanol for 2 to 3 times, and dry in a vacuum drying oven at 30 to 40° C. to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0027] 2) Add polyaspartic acid powder and water in a ratio of 1 g: 20-30 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 110-120° C. for 6-8 hours, filter and dry to obtain modified microcrystalline fiber for later use;

[0028] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:0.8-1.4, grinding at 1000-2000 rpm for 12-18 min, immersing in a treatment agent, heating to 60-80°C, stirring at 200-300 rpm for 2-3 h, filtering, washing with deionized water to neutrality, and then placing in a vacuum drying oven, drying at 30-50°C to constant weight to obtain a composite carrier powder for standby use;

[0029] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at a constant temperature of 40-60°C and 200-300 rpm for 1-2 hours, let it stand for 10-20 hours, then filter it, place it in a vacuum drying oven, dry it to constant weight at 30-50°C, transfer it to a muffle furnace, and calcine it at 400-500°C for 4-6 hours to obtain the supported metal oxide catalyst.

[0030] Preferably, the added amounts of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO in step 1) are respectively 0.4-0.8 mmol / g, 18-24 mmol / g and 16-20 mmol / g based on the weight of microcrystalline cellulose.

[0031] Preferably, the components and corresponding weight percentages of the treatment agent in step 3) are: 2-3% divinyl sulfone, 7-15% soybean lecithin, 1-3% ammonium bicarbonate, and the balance is deionized water.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] The present invention provides a tail gas treatment method for methyl thiophanate production, the purification efficiency of hydrogen sulfide, hydrogen chloride, volatile compounds VOCs and other impurities reaches 100% in 200 minutes, and the effective purification time of the modified molecular sieve composite adsorbent and the catalyst used for catalytic oxidation of the present invention is up to 13200 minutes, and the service life is long. The tail gas treatment capacity per unit mass of the modified molecular sieve composite adsorbent used in the purification is as high as 603.21-623.28m 3 kg -1 The tail gas treatment capacity of the catalyst used for catalytic oxidation is as high as 439.98~470.03m 3 kg -1 , the purification effect is remarkable.

[0034] First, through two vacuum and low temperature processes, the water is fully dried to remove the moisture and improve the activity. Through the control of the treatment dosage and parameters, the trimethylchlorosilane modifies the outer surface of the molecular sieve while allowing some molecules to enter the crystal interior for grafting, thereby improving the performance of the ZSM-5 molecular sieve and improving its hydrophobicity. The amide group is introduced into the chitosan to reduce the hydrogen bonding between the chitosan molecules and improve its hydrophobicity. Then, it is acylated with the amino group on the chloroacetyl chloride to further hydrophobicity and enhance its thermal and chemical stability. It is then made into a porous, stable modified molecular sieve composite adsorbent together with the ZSM-5 molecular sieve. This adsorbent has good hydrophobicity, will not be affected by water vapor in the exhaust gas, has good adsorption selectivity for the exhaust gas, has a significant purification time and effect, and has a long service life.

[0035] Secondly, polyaspartic acid is grafted onto carboxylated microcrystalline cellulose through an amidation reaction to improve the dispersibility of the microcrystalline cellulose. After grinding and mixing it with γ-Al2O3 powder, it is treated with a treating agent to form a stable physical-chemical cross-linked network structure to prepare a porous and thermally stable composite carrier. When added to a Cu(NO3)2 solution, a highly active supported metal oxide catalyst is prepared. This catalyst is used in the catalytic oxidation of exhaust gas treatment and can play a long-lasting and efficient purification role.

[0036] Finally, the condensation treatment, adsorbent adsorption treatment and catalytic oxidation method in the present invention cooperate with each other to achieve a purification efficiency of 100% for the tail gas produced by thiophanate-methyl. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the purification efficiency curve of Example 2. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0041] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0042] S2, using a modified molecular sieve composite adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0043] The preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0044] (1) The ZSM-5 molecular sieve is placed in a vacuum drying oven and dried at 20°C for 3 hours. The dried ZSM-5 molecular sieve is placed in a muffle furnace and heated to 550°C at 3°C / min, calcined at high temperature for 4 hours, cooled to room temperature, ultrasonically dispersed in anhydrous ethanol, and then trimethylchlorosilane is added and mixed and shaken. The mixture is condensed and refluxed at 60°C for 4 hours, and then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture is placed in a vacuum drying oven and dried at 20°C for 10 hours. Finally, the mixture is placed in a muffle furnace and calcined at 500°C for 4 hours to obtain a hydrophobic modified ZSM-5 molecular sieve.

[0045] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:6 mL;

[0046] The weight volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.4 mL;

[0047] (2) chitosan is added to an acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, and the temperature is raised to 40° C., and 0.1 times the mass of the chitosan ammonium cerium nitrate and an acrylamide aqueous solution (40%) are added in sequence. After constant temperature reaction for 3 hours, 2 drops of hydroquinone are added to terminate the reaction. After cooling to room temperature, the product is neutralized with a 5% NaOH aqueous solution to precipitate, filtered and immersed in anhydrous ethanol, and then 0.06 times the mass of the chitosan chloroacetyl chloride is added and stirred. After stirring and reacting at 40° C. and 200 rpm for 2 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) with a mass of 10 times that of the chitosan is added. After stirring at 300 rpm for 6 hours, the solution is filtered, washed with anhydrous ethanol for 3 times, and then placed in a vacuum drying oven and dried at 30° C. to obtain a modified molecular sieve composite adsorbent;

[0048] The volume ratio of the 1% chitosan acetic acid solution to deionized water is 1:0.2;

[0049] The mass ratio of chitosan to acrylamide is 1:4;

[0050] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0051] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0052] The preparation of the supported metal oxide catalyst comprises the following steps:

[0053] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 20 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react at 50°C in a water bath for 12 hours, then add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water for 3 times, then wash with 50% ethanol for 2 times, and then dry in a vacuum drying oven at 30°C to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0054] The added amounts of the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO are respectively 0.4 mmol / g, 18 mmol / g and 16 mmol / g based on the weight of microcrystalline cellulose;

[0055] 2) Add polyaspartic acid powder and water in a ratio of 1 g: 20 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 110° C. for 6 h, filter and dry to obtain modified microcrystalline fiber for later use;

[0056] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:0.8, grinding at 1000 rpm for 12 min, immersing in a treatment agent, heating to 60°C, stirring at 200 rpm for 2 h, filtering, washing with deionized water until neutral, and then placing in a vacuum drying oven, drying at 30°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treatment agent are: 2% divinyl sulfone, 7% soybean lecithin, 1% ammonium bicarbonate, and the balance is deionized water;

[0057] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 40°C and 200 rpm for 1 hour, let it stand for 10 hours, then filter it, place it in a vacuum drying oven, dry it to constant weight at 30°C, transfer it to a muffle furnace, and calcine it at 400°C for 4 hours to obtain the supported metal oxide catalyst.

[0058] Example 2

[0059] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0060] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0061] S2, using a modified molecular sieve composite adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0062] The preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0063] (1) The ZSM-5 molecular sieve is placed in a vacuum drying oven and dried at 25°C for 4 hours. The dried ZSM-5 molecular sieve is placed in a muffle furnace and heated to 550°C at 3°C / min, calcined at high temperature for 4 hours, cooled to room temperature, ultrasonically dispersed in anhydrous ethanol, and then trimethylchlorosilane is added and mixed and shaken. The mixture is condensed and refluxed at 70°C for 12 hours, and then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture is placed in a vacuum drying oven and dried at 25°C for 11 hours. Finally, the mixture is placed in a muffle furnace and calcined at 550°C for 4 hours to obtain a hydrophobic modified ZSM-5 molecular sieve.

[0064] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:13 mL;

[0065] The weight volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.8 mL;

[0066] (2) chitosan is added to an acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, and the temperature is raised to 45° C., 0.2 times the mass of the chitosan ammonium cerium nitrate and an acrylamide aqueous solution (40%) are added in sequence. After constant temperature reaction for 3.5 hours, 2 drops of hydroquinone are added to terminate the reaction. After cooling to room temperature, the solution is neutralized with a 5% NaOH aqueous solution to precipitate the product. After filtering, the solution is immersed in anhydrous ethanol, and then 0.07 times the mass of the chitosan chloroacetyl chloride is added and stirred. After stirring and reacting at 50° C. and 250 rpm for 2.5 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) with a mass of 15 times the mass of the chitosan is added. After stirring at 350 rpm for 7 hours, the solution is filtered, washed with anhydrous ethanol for 4 times, and then placed in a vacuum drying oven and dried at 35° C. to obtain a modified molecular sieve composite adsorbent;

[0067] The volume ratio of the 1% chitosan acetic acid solution to deionized water is 1:0.25;

[0068] The mass ratio of chitosan to acrylamide is 1:6;

[0069] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0070] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0071] The preparation of the supported metal oxide catalyst comprises the following steps:

[0072] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 25 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react at 60°C in a water bath for 16 hours, then add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water 4 times, then wash with 50% ethanol 2 times, and dry in a vacuum drying oven at 35°C to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0073] The added amounts of the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO are respectively 0.6 mmol / g, 21 mmol / g and 18 mmol / g based on the weight of microcrystalline cellulose;

[0074] 2) Add polyaspartic acid powder and water in a ratio of 1 g: 25 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 115° C. for 7 h, filter and dry to obtain modified microcrystalline fiber for later use;

[0075] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:1.1, grinding at 1500rpm for 15min, immersing in a treating agent, heating to 70°C, stirring at 250rpm for 2.5h, filtering, washing with deionized water until neutral, and then placing in a vacuum drying oven, drying at 40°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treating agent are: 2.5% divinyl sulfone, 11% soybean lecithin, 2% ammonium bicarbonate, and the balance is deionized water;

[0076] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 50°C and 250 rpm for 1.5 h, let it stand for 15 h, then filter it, place it in a vacuum drying oven, dry it at 40°C to constant weight, transfer it to a muffle furnace, and calcine it at 450°C for 5 h to obtain the supported metal oxide catalyst.

[0077] Example 3

[0078] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0079] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0080] S2, using a modified molecular sieve composite adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0081] The preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0082] (1) The ZSM-5 molecular sieve is placed in a vacuum drying oven and dried at 30°C for 5 hours. The dried ZSM-5 molecular sieve is placed in a muffle furnace and heated to 550°C at 3°C / min, calcined at high temperature for 4 hours, cooled to room temperature, ultrasonically dispersed in anhydrous ethanol, and then trimethylchlorosilane is added and mixed and shaken. The mixture is condensed and refluxed at 80°C for 20 hours, and then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture is then placed in a vacuum drying oven and dried at 30°C for 12 hours. Finally, the mixture is placed in a muffle furnace and calcined at 600°C for 4 hours to obtain a hydrophobic modified ZSM-5 molecular sieve.

[0083] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:20 mL;

[0084] The weight volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:1.2mL;

[0085] (2) chitosan is added to an acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, and the temperature is raised to 50° C., 0.3 times the mass of the chitosan ammonium cerium nitrate and an acrylamide aqueous solution (40%) are added in sequence. After constant temperature reaction for 4 hours, 3 drops of hydroquinone are added to terminate the reaction. After cooling to room temperature, the solution is neutralized with a 5% NaOH aqueous solution to precipitate the product, filtered and immersed in anhydrous ethanol, and then 0.08 times the mass of the chitosan chloroacetyl chloride is added and stirred. After stirring and reacting at 60° C. and 300 rpm for 3 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) with a mass of 20 times that of the chitosan is added. After stirring at 400 rpm for 8 hours, the solution is filtered, washed with anhydrous ethanol for 5 times, and then placed in a vacuum drying oven and dried at 40° C. to obtain a modified molecular sieve composite adsorbent;

[0086] The volume ratio of the 1% chitosan acetic acid solution to deionized water is 1:0.3;

[0087] The mass ratio of chitosan to acrylamide is 1:8;

[0088] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0089] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0090] The preparation of the supported metal oxide catalyst comprises the following steps:

[0091] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 30 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react at 70°C in a water bath for 20 hours, add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water 5 times, then wash with 50% ethanol 3 times, and dry in a vacuum drying oven at 40°C to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0092] The added amounts of the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO are respectively 0.8 mmol / g, 24 mmol / g and 20 mmol / g based on the weight of microcrystalline cellulose;

[0093] 2) Add polyaspartic acid powder and water in a ratio of 1 g:30 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 120° C. for 8 h, filter and dry to obtain modified microcrystalline fiber for later use;

[0094] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:1.4, grinding at 2000 rpm for 18 min, immersing in a treatment agent, heating to 80°C, stirring at 300 rpm for 3 h, filtering, washing with deionized water until neutral, and then placing in a vacuum drying oven, drying at 50°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treatment agent are: 3% divinyl sulfone, 15% soybean lecithin, 3% ammonium bicarbonate, and the balance is deionized water;

[0095] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 60°C and 300 rpm for 2 hours, let it stand for 20 hours, then filter it, place it in a vacuum drying oven, dry it at 50°C to constant weight, transfer it to a muffle furnace, and calcine it at 500°C for 6 hours to obtain the supported metal oxide catalyst.

[0096] Comparative Example 1

[0097] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0098] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0099] S2, using ZSM-5 molecular sieve to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain the secondary treated tail gas;

[0100] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0101] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0102] The preparation of the supported metal oxide catalyst comprises the following steps:

[0103] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 25 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react at 60°C in a water bath for 16 hours, then add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water 4 times, then wash with 50% ethanol 2 times, and dry in a vacuum drying oven at 35°C to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0104] The added amounts of the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO are respectively 0.6 mmol / g, 21 mmol / g and 18 mmol / g based on the weight of microcrystalline cellulose;

[0105] 2) Add polyaspartic acid powder and water in a ratio of 1 g: 25 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 115° C. for 7 h, filter and dry to obtain modified microcrystalline fiber for later use;

[0106] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:1.1, grinding at 1500rpm for 15min, immersing in a treating agent, heating to 70°C, stirring at 250rpm for 2.5h, filtering, washing with deionized water until neutral, and then placing in a vacuum drying oven, drying at 40°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treating agent are: 2.5% divinyl sulfone, 11% soybean lecithin, 2% ammonium bicarbonate, and the balance is deionized water;

[0107] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 50°C and 250 rpm for 1.5 h, let it stand for 15 h, then filter it, place it in a vacuum drying oven, dry it at 40°C to constant weight, transfer it to a muffle furnace, and calcine it at 450°C for 5 h to obtain the supported metal oxide catalyst.

[0108] Comparative Example 2

[0109] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0110] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0111] S2, using a modified molecular sieve composite adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0112] The preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0113] (1) The ZSM-5 molecular sieve is placed in a vacuum drying oven and dried at 25°C for 4 hours. The dried ZSM-5 molecular sieve is placed in a muffle furnace and heated to 550°C at 3°C / min, calcined at high temperature for 4 hours, cooled to room temperature, ultrasonically dispersed in anhydrous ethanol, and then trimethylchlorosilane is added and mixed and shaken. The mixture is condensed and refluxed at 70°C for 12 hours, and then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture is placed in a vacuum drying oven and dried at 25°C for 11 hours. Finally, the mixture is placed in a muffle furnace and calcined at 550°C for 4 hours to obtain a hydrophobic modified ZSM-5 molecular sieve.

[0114] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:13 mL;

[0115] The weight volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.8 mL;

[0116] (2) adding chitosan to an acetic acid solution to prepare a 1% chitosan acetic acid solution, adding 15 times the mass of chitosan of the hydrophobic modified ZSM-5 molecular sieve prepared in step (1), stirring at 350 rpm for 7 hours, filtering, washing with anhydrous ethanol for 4 times, placing in a vacuum drying oven, and drying at 35° C. to obtain a modified molecular sieve composite adsorbent;

[0117] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0118] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0119] The preparation of the supported metal oxide catalyst comprises the following steps:

[0120] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 25 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react at 60°C in a water bath for 16 hours, then add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water 4 times, then wash with 50% ethanol 2 times, and dry in a vacuum drying oven at 35°C to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0121] The added amounts of the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO are respectively 0.6 mmol / g, 21 mmol / g and 18 mmol / g based on the weight of microcrystalline cellulose;

[0122] 2) Add polyaspartic acid powder and water in a ratio of 1 g: 25 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 115° C. for 7 h, filter and dry to obtain modified microcrystalline fiber for later use;

[0123] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:1.1, grinding at 1500rpm for 15min, immersing in a treating agent, heating to 70°C, stirring at 250rpm for 2.5h, filtering, washing with deionized water until neutral, and then placing in a vacuum drying oven, drying at 40°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treating agent are: 2.5% divinyl sulfone, 11% soybean lecithin, 2% ammonium bicarbonate, and the balance is deionized water;

[0124] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 50°C and 250 rpm for 1.5 h, let it stand for 15 h, then filter it, place it in a vacuum drying oven, dry it at 40°C to constant weight, transfer it to a muffle furnace, and calcine it at 450°C for 5 h to obtain the supported metal oxide catalyst.

[0125] Comparative Example 3

[0126] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0127] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0128] S2, using hydrophobic modified ZSM-5 molecular sieve to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain the secondary treated tail gas;

[0129] The preparation of the hydrophobic modified ZSM-5 molecular sieve comprises the following steps:

[0130] The ZSM-5 molecular sieve was placed in a vacuum drying oven and dried at 25°C for 4 hours. The dried ZSM-5 molecular sieve was placed in a muffle furnace and heated to 550°C at 3°C / min, and calcined at high temperature for 4 hours. The dried ZSM-5 molecular sieve was cooled to room temperature and ultrasonically dispersed in anhydrous ethanol. Then trimethylchlorosilane was added and mixed and shaken. The mixture was condensed and refluxed at 70°C for 12 hours. The mixture was then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture was placed in a vacuum drying oven and dried at 25°C for 11 hours. Finally, the mixture was placed in a muffle furnace and calcined at 550°C for 4 hours to obtain the hydrophobic modified ZSM-5 molecular sieve.

[0131] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:13 mL;

[0132] The weight-to-volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.8 mL.

[0133] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0134] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0135] The preparation of the supported metal oxide catalyst comprises the following steps:

[0136] 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 25 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react at 60°C in a water bath for 16 hours, then add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water 4 times, then wash with 50% ethanol 2 times, and dry in a vacuum drying oven at 35°C to constant weight to obtain carboxylated microcrystalline cellulose for use;

[0137] The added amounts of the 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO are respectively 0.6 mmol / g, 21 mmol / g and 18 mmol / g based on the weight of microcrystalline cellulose;

[0138] 2) Add polyaspartic acid powder and water in a ratio of 1 g: 25 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 115° C. for 7 h, filter and dry to obtain modified microcrystalline fiber for later use;

[0139] 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:1.1, grinding at 1500rpm for 15min, immersing in a treating agent, heating to 70°C, stirring at 250rpm for 2.5h, filtering, washing with deionized water until neutral, and then placing in a vacuum drying oven, drying at 40°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treating agent are: 2.5% divinyl sulfone, 11% soybean lecithin, 2% ammonium bicarbonate, and the balance is deionized water;

[0140] 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 50°C and 250 rpm for 1.5 h, let it stand for 15 h, then filter it, place it in a vacuum drying oven, dry it at 40°C to constant weight, transfer it to a muffle furnace, and calcine it at 450°C for 5 h to obtain the supported metal oxide catalyst.

[0141] Comparative Example 4

[0142] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0143] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0144] S2, using a modified molecular sieve composite adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0145] The preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0146] (1) The ZSM-5 molecular sieve is placed in a vacuum drying oven and dried at 25°C for 4 hours. The dried ZSM-5 molecular sieve is placed in a muffle furnace and heated to 550°C at 3°C / min, calcined at high temperature for 4 hours, cooled to room temperature, ultrasonically dispersed in anhydrous ethanol, and then trimethylchlorosilane is added and mixed and shaken. The mixture is condensed and refluxed at 70°C for 12 hours, and then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture is placed in a vacuum drying oven and dried at 25°C for 11 hours. Finally, the mixture is placed in a muffle furnace and calcined at 550°C for 4 hours to obtain a hydrophobic modified ZSM-5 molecular sieve.

[0147] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:13 mL;

[0148] The weight volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.8 mL;

[0149] (2) chitosan is added to an acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, and the temperature is raised to 45° C., 0.2 times the mass of the chitosan ammonium cerium nitrate and an acrylamide aqueous solution (40%) are added in sequence. After constant temperature reaction for 3.5 hours, 2 drops of hydroquinone are added to terminate the reaction. After cooling to room temperature, the solution is neutralized with a 5% NaOH aqueous solution to precipitate the product. After filtering, the solution is immersed in anhydrous ethanol, and then 0.07 times the mass of the chitosan chloroacetyl chloride is added and stirred. After stirring and reacting at 50° C. and 250 rpm for 2.5 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) with a mass of 15 times the mass of the chitosan is added. After stirring at 350 rpm for 7 hours, the solution is filtered, washed with anhydrous ethanol for 4 times, and then placed in a vacuum drying oven and dried at 35° C. to obtain a modified molecular sieve composite adsorbent;

[0150] The volume ratio of the 1% chitosan acetic acid solution to deionized water is 1:0.25;

[0151] The mass ratio of chitosan to acrylamide is 1:6;

[0152] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0153] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0154] The preparation of the supported metal oxide catalyst comprises the following steps:

[0155] 1) γ-Al2O3 powder and microcrystalline cellulose are placed in a bead mill at a weight ratio of 1:1.1, ground at 1500 rpm for 15 min, immersed in a treatment agent, heated to 70°C, stirred at 250 rpm for 2.5 h, filtered, washed with deionized water until neutral, and then placed in a vacuum drying oven and dried at 40°C to constant weight to obtain a composite carrier powder for standby use; the components and corresponding weight percentages in the treatment agent are: 2.5% divinyl sulfone, 11% soybean lecithin, 2% ammonium bicarbonate, and the balance is deionized water;

[0156] 2) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at 50°C and 250 rpm for 1.5 h, let it stand for 15 h, filter it, place it in a vacuum drying oven, dry it at 40°C to constant weight, transfer it to a muffle furnace, and calcine it at 450°C for 5 h to obtain the supported metal oxide catalyst.

[0157] Comparative Example 5

[0158] A tail gas treatment method for thiophanate-methyl production comprises the following steps:

[0159] S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas;

[0160] S2, using a modified molecular sieve composite adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas;

[0161] The preparation of the modified molecular sieve composite adsorbent comprises the following steps:

[0162] (1) The ZSM-5 molecular sieve is placed in a vacuum drying oven and dried at 25°C for 4 hours. The dried ZSM-5 molecular sieve is placed in a muffle furnace and heated to 550°C at 3°C / min, calcined at high temperature for 4 hours, cooled to room temperature, ultrasonically dispersed in anhydrous ethanol, and then trimethylchlorosilane is added and mixed and shaken. The mixture is condensed and refluxed at 70°C for 12 hours, and then cooled, filtered, and washed with anhydrous ethanol for 3 times. The mixture is placed in a vacuum drying oven and dried at 25°C for 11 hours. Finally, the mixture is placed in a muffle furnace and calcined at 550°C for 4 hours to obtain a hydrophobic modified ZSM-5 molecular sieve.

[0163] The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol is 1 g:13 mL;

[0164] The weight volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.8 mL;

[0165] (2) chitosan is added to an acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, and the temperature is raised to 45° C., 0.2 times the mass of the chitosan ammonium cerium nitrate and an acrylamide aqueous solution (40%) are added in sequence. After constant temperature reaction for 3.5 hours, 2 drops of hydroquinone are added to terminate the reaction. After cooling to room temperature, the solution is neutralized with a 5% NaOH aqueous solution to precipitate the product. After filtering, the solution is immersed in anhydrous ethanol, and then 0.07 times the mass of the chitosan chloroacetyl chloride is added and stirred. After stirring and reacting at 50° C. and 250 rpm for 2.5 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) with a mass of 15 times the mass of the chitosan is added. After stirring at 350 rpm for 7 hours, the solution is filtered, washed with anhydrous ethanol for 4 times, and then placed in a vacuum drying oven and dried at 35° C. to obtain a modified molecular sieve composite adsorbent;

[0166] The volume ratio of the 1% chitosan acetic acid solution to deionized water is 1:0.25;

[0167] The mass ratio of chitosan to acrylamide is 1:6;

[0168] S3, using catalytic oxidation method to catalytically oxidize the secondary treated tail gas and then discharge it;

[0169] The catalyst used in the catalytic oxidation method is a supported metal oxide catalyst;

[0170] The preparation of the supported metal oxide catalyst comprises the following steps:

[0171] The γ-Al2O3 powder was placed in a bead mill, ground at 1500 rpm for 15 min, immersed in a treating agent, heated to 70°C, stirred at 250 rpm for 2.5 h, filtered, washed with deionized water until neutral, placed in a vacuum drying oven, dried to constant weight at 40°C, added to a Cu(NO3)2 solution, stirred at 50°C and 250 rpm for 1.5 h, allowed to stand for 15 h, filtered, placed in a vacuum drying oven, dried to constant weight at 40°C, transferred to a muffle furnace, and calcined at 450°C for 5 h to obtain a supported metal oxide catalyst.

[0172] Detection

[0173] The tail gas produced by methyl thiophanate was purified by the methods in Examples 1 to 3 and Comparative Examples 1 to 5. The contents of hydrogen sulfide, hydrogen chloride, volatile compounds (VOCs), etc. in the raw gas and the purified gas were determined. The tail gas treatment capacity per unit mass of the modified molecular sieve composite adsorbent (catalyst) and the tail gas purification efficiency of Example 2 were calculated by the following formula.

[0174] The tail gas treatment capacity per unit mass of adsorbent is calculated using formula (1):

[0175] (1)

[0177] The tail gas treatment capacity per unit mass of adsorbent is calculated using formula (2):

[0178] (2)

[0180] The exhaust gas purification efficiency is calculated using formula (3):

[0181]

[0182] The test results are shown in Table 1 below:

[0183] Table 1

[0184]

[0185] From Table 1 above, it can be seen that the tail gas treatment capacity per unit mass of the modified molecular sieve composite adsorbent of Examples 1 to 3 is as high as 603.21 to 623.28 m3 kg -1 The tail gas treatment capacity of the catalyst used for catalytic oxidation is as high as 439.98~470.03m 3 kg -1 The purification effect is significantly better than that of comparative examples 1 to 5.

[0186] Depend on Figure 1 It can be seen that the tail gas treatment method applied to the production of methyl thiophanate of the present invention has a purification efficiency of 100% for impurities such as hydrogen sulfide, hydrogen chloride, and volatile compounds VOCs in 200 minutes, and the modified molecular sieve composite adsorbent of the present invention and the catalyst used for catalytic oxidation have an effective purification time of up to 13200 minutes and a long service life.

[0187] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A tail gas treatment method for the production of thiophanate-methyl, characterized in that: The steps include: S1, condensing and treating the collected tail gas through an absorber to absorb and remove part of the organic solvent and part of the water to obtain a preliminary treated tail gas; S2, using a solid adsorbent to adsorb and separate the primary treated tail gas to remove part of the organic solvent and most of the water to obtain a secondary treated tail gas; S3. The secondary treated tail gas is subjected to catalytic oxidation treatment by catalytic oxidation and then discharged.

2. A tail gas treatment method for the production of thiophanate-methyl according to claim 1, characterized in that: The adsorbent is a modified molecular sieve composite adsorbent.

3. A tail gas treatment method for the production of thiophanate-methyl according to claim 2, characterized in that: The preparation of the modified molecular sieve composite adsorbent comprises the following steps: (1) placing the ZSM-5 molecular sieve in a vacuum drying oven, drying it at 20-30°C for 3-5h, placing the dried ZSM-5 molecular sieve in a muffle furnace, heating it to 550°C at 3°C / min, high temperature roasting it for 4h, cooling it to room temperature, ultrasonically dispersing it in anhydrous ethanol, then adding trimethylchlorosilane, mixing and shaking it, condensing and refluxing it at 60-80°C for 4-20h, then cooling, filtering, washing it with anhydrous ethanol for 3 times, placing it in a vacuum drying oven, drying it at 20-30°C for 10-12h, and finally placing it in a muffle furnace and roasting it at 500-600°C for 4h to obtain a hydrophobic modified ZSM-5 molecular sieve; (2) chitosan is added to acetic acid solution to prepare a 1% chitosan acetic acid solution, which is added to a three-necked flask, and then deionized water is added. After stirring and mixing, the solution is placed in a water bath, heated to 40-50° C., and then ammonium cerium nitrate and acrylamide aqueous solution are added in sequence. After constant temperature reaction for 3-4 hours, hydroquinone is added dropwise to terminate the reaction. After cooling to room temperature, the solution is neutralized with a 5% NaOH aqueous solution to precipitate the product. After filtering, the solution is immersed in anhydrous ethanol, and then chloroacetyl chloride is added and stirred. After stirring and reacting at 40-60° C. and 200-300 rpm for 2-3 hours, the hydrophobic modified ZSM-5 molecular sieve prepared in step (1) is added, and after stirring at 300-400 rpm for 6-8 hours, the solution is filtered, washed with anhydrous ethanol for 3-5 times, and then placed in a vacuum drying oven and dried at 30-40° C. to obtain a modified molecular sieve composite adsorbent.

4. A tail gas treatment method for the production of thiophanate-methyl according to claim 3, characterized in that: The weight volume ratio of the ZSM-5 molecular sieve to anhydrous ethanol in step (1) is 1 g: 6-20 mL; The weight-to-volume ratio of the ZSM-5 molecular sieve to trimethylchlorosilane is 1:0.4-1.2 mL.

5. The tail gas treatment method for thiophanate-methyl production according to claim 3, characterized in that: The volume ratio of the 1% chitosan acetic acid solution to deionized water in step (2) is 1:0.2-0.3; The mass ratio of the ammonium cerium nitrate to chitosan is 1:0.1-0.3; The mass ratio of chitosan to acrylamide is 1:4-8; The concentration of the acrylamide aqueous solution is 40%; The amount of the hydroquinone added is 2 to 3 drops; The mass ratio of chitosan to chloroacetyl chloride is 1:0.06-0.08; The mass ratio of the chitosan to the hydrophobic modified ZSM-5 molecular sieve is 1:10-20.

6. The tail gas treatment method for thiophanate-methyl production according to claim 1, characterized in that: The catalyst used in the catalytic oxidation method described in step S3 is a supported metal oxide catalyst.

7. The tail gas treatment method for thiophanate-methyl production according to claim 1, characterized in that: The preparation of the supported metal oxide catalyst comprises the following steps: 1) Add microcrystalline cellulose to a three-necked flask containing sodium phosphate buffer solution, stir for 20 to 30 minutes, then add 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO solution, react in a water bath at 50 to 70° C. for 12 to 20 hours, add anhydrous ethanol to terminate the reaction, let stand to separate, wash with deionized water for 3 to 5 times, then wash with 50% ethanol for 2 to 3 times, and dry in a vacuum drying oven at 30 to 40° C. to constant weight to obtain carboxylated microcrystalline cellulose for use; 2) Add polyaspartic acid powder and water in a ratio of 1 g: 20-30 mL into a beaker and stir to mix, then add the above-mentioned carboxylated microcrystalline cellulose, disperse evenly by ultrasonication, place in an oil bath, condense and reflux at 110-120° C. for 6-8 hours, filter and dry to obtain modified microcrystalline fiber for later use; 3) placing γ-Al2O3 powder and modified microcrystalline cellulose in a bead mill at a weight ratio of 1:0.8-1.4, grinding at 1000-2000 rpm for 12-18 min, immersing in a treatment agent, heating to 60-80°C, stirring at 200-300 rpm for 2-3 h, filtering, washing with deionized water to neutrality, and then placing in a vacuum drying oven, drying at 30-50°C to constant weight to obtain a composite carrier powder for standby use; 4) Add the composite carrier powder obtained in step 1) to the Cu(NO3)2 solution, stir at a constant temperature of 40-60°C and 200-300 rpm for 1-2 hours, let it stand for 10-20 hours, then filter it, place it in a vacuum drying oven, dry it to constant weight at 30-50°C, transfer it to a muffle furnace, and calcine it at 400-500°C for 4-6 hours to obtain the supported metal oxide catalyst.

8. A tail gas treatment method for thiophanate-methyl production according to claim 7, characterized in that: The added amounts of 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, NaClO2 and NaClO described in step 1) are respectively 0.4-0.8 mmol / g, 18-24 mmol / g and 16-20 mmol / g based on the weight of microcrystalline cellulose.

9. A tail gas treatment method for thiophanate-methyl production according to claim 7, characterized in that: The components and corresponding weight percentages of the treatment agent in step 3) are: 2-3% divinyl sulfone, 7-15% soybean lecithin, 1-3% ammonium bicarbonate, and the balance is deionized water.

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