Modified filler capable of efficiently inhibiting adsorption and desorption of dioxin and preparation method thereof

Abstract

The present application relates to solid waste incineration disposal technology, aiming at providing a modified filler capable of efficiently inhibiting dioxin adsorption and desorption and a preparation method thereof. The modified filler is obtained by injection molding of a mixture of polypropylene base material and hydrophilic auxiliary agent; the modified filler has hydrophilicity, and the surface contact angle of the product is less than 90°; the hydrophilic auxiliary agent is at least one of organic hydrophilic auxiliary agent or inorganic hydrophilic auxiliary agent, and at least contains one hydrophilic group of -COOH, -OH, -CO; the inorganic hydrophilic auxiliary agent is at least one of silicon dioxide, talcum powder and glass fiber. The hydrophilic filler prepared by the present application can efficiently inhibit the adsorption and desorption of dioxin in the filler; has the advantages of convenient operation and simple process, and does not need to adjust and change the existing wet washing system; the components of the filler are widely sourced, and the price is low, and has important application value for solving the emission problem of dioxin in the waste incineration process.

Description

TECHNICAL FIELD

[0001] The present application relates to solid waste incineration disposal technology, in particular to a preparation method of modified filler capable of efficiently inhibiting adsorption and desorption of dioxin, which is used for inhibiting the increase of dioxin emission concentration caused by adsorption and desorption of dioxin on the filler in the tower in the wet scrubbing process. BACKGROUND

[0002] Solid waste generally includes municipal solid waste, hazardous solid waste and industrial solid waste, and its production quantity shows a rapid growth trend year by year. Incineration disposal of solid waste has advantages such as reduction and resource utilization, and the disposal proportion is increasing year by year, which is the main way of solid waste disposal in China. However, secondary pollutants such as acid gases (HCl, SO2), dust, NO x , dioxin and the like are easily produced in the process of incineration disposal of solid waste, which poses a great threat to the environment. Therefore, the emission control problem of the above pollutants in the process of incineration disposal of solid waste needs to be solved urgently.

[0003] In order to effectively control the emission of acid gases (HCl, SO2) and dust, more and more wet scrubbing towers are introduced into the flue gas purification system matched with the solid waste incineration, the main purpose of which is to capture and reduce the concentration of acid gases (HCl, SO2) and dust in the flue gas through the contact between the alkali liquor circulating water and the flue gas, so as to realize the standard or ultra-low emission of acid gas and dust pollutants. In order to achieve the above purpose, a filler layer needs to be arranged in the wet scrubbing tower, and polypropylene filler is mainly used to fill the wet scrubbing tower. The specific working mode includes: 1) placing the filler below the alkali liquor nozzle to increase the gas-liquid contact area and improve the deacidification efficiency; 2) placing the filler above the alkali liquor nozzle to reduce the moisture in the flue gas and to dehumidify and demist.

[0004] Under the effective work of the pre-flue gas purification equipment, the dioxin concentration of the flue gas at the inlet of the wet scrubbing tower is usually reduced to a low level. However, since the polypropylene filler in the wet scrubbing tower has affinity for dioxin-like pollutants, it will promote the accumulation of dioxin in the filler layer. When the combustion condition of the incinerator fluctuates greatly or changes, or when the front-end flue gas purification facility fails or the dioxin removal efficiency is low, the polypropylene filler is easy to release the dioxin accumulated in the early stage into the flue gas, causing the concentration of dioxin in the end emission flue gas to rise. This results in that the dioxin concentration at the outlet of the wet scrubbing tower is higher than that at the inlet, and even the phenomenon of exceeding the standard occurs. The existing research refers to this phenomenon as the "memory effect" of dioxin in the wet scrubbing tower.

[0005] Therefore, it is urgent to develop a new type of modified filler which can weaken the memory effect of dioxin, so as to ensure the efficient removal of acid pollutants in the solid waste incineration tail gas, reduce the risk of the increase or even exceeding of the dioxin concentration in the flue gas, and have important application value for continuously and stably meeting the standard of dioxin emission in the waste incineration flue gas. SUMMARY

[0006] The technical problem solved by the present application is to overcome the deficiencies in the prior art and provide a preparation method of modified filler capable of efficiently inhibiting dioxin adsorption and desorption.

[0007] To solve the above technical problem, the solution of the present application is:

[0008] The present application provides a modified filler capable of efficiently inhibiting dioxin adsorption and desorption, which is obtained by injection molding a mixture of polypropylene base material and hydrophilic auxiliary agent; the modified filler has hydrophilicity, and the surface contact angle of the product is less than 90°.

[0009] The hydrophilic auxiliary agent is at least one of an organic hydrophilic auxiliary agent or an inorganic hydrophilic auxiliary agent; wherein the organic hydrophilic auxiliary agent contains at least one hydrophilic group of -COOH, -OH, and -CO, and the inorganic hydrophilic auxiliary agent is at least one of silicon dioxide, talcum powder, and glass fiber.

[0010] In the mixture, the mass content of the polypropylene base material is 66.5-98.0 wt.%, and the mass content of the hydrophilic auxiliary agent is 2.0-33.5 wt.%.

[0011] As a preferred scheme of the present application, the polypropylene base material is random copolymerized polypropylene.

[0012] As a preferred scheme of the present application, the organic hydrophilic auxiliary agent is at least one of polyvinylpyrrolidone, maleic anhydride grafted polypropylene, ethylene-acrylic acid copolymer, maleic acid-acrylic acid copolymer, ethylene-vinyl alcohol copolymer, and hydroxyethyl methyl cellulose.

[0013] As a preferred scheme of the present application, the structure of the modified filler is any one of high-flow ring, flower ring, Bauer ring, Hail ring, or conjugate ring.

[0014] The present application further provides a preparation method of the aforementioned modified filler, comprising the following steps:

[0015] (1) The polypropylene base material and the hydrophilic auxiliary agent are weighed according to the mass percentage relationship and mixed uniformly;

[0016] (2) The uniform mixture is added to the hopper of an injection molding machine, and a three-dimensional structure of the modified filler product is prepared by an injection molding process.

[0017] As a preferred scheme of the present application, when injection molding, the plasticizing zone temperature of the injection molding machine is set to 230-240℃.

[0018] As a preferred scheme of the present application, the hydrophilic auxiliary agent is in powder or granular form.

[0019] As a preferred scheme of the present application, the hydrophilic auxiliary agent at least comprises one of silica or polyvinylpyrrolidone.

[0020] Invention principle description:

[0021] Polypropylene, which is widely used as a filler material, is a typical non-polar polymer material, and has a small surface tension, poor wettability, a surface water contact angle usually greater than 100°, a small wetting and spreading area of liquid on the filler surface, and a surface easily adsorbing hydrophobic or amphiphilic solutes (including dust particles). The polypropylene has affinity for dioxins, and gradually accumulates dioxins in the wet scrubber filler as the running time is prolonged. The adsorbed dioxins are easily released when the operating parameters or flue gas parameters in the wet scrubber change.

[0022] The filler layer is the part with the highest dioxin accumulation in the wet scrubber, and the modification of the filler is expected to inhibit the formation of the dioxin memory effect. In order to avoid the adsorption of dioxins by the strengthened filler and the inhibition of the corresponding desorption performance, the filler becomes a hazardous waste, and the operating cost of replacing the filler is increased. The present application uses the preparation steps of the commercial polypropylene filler, and adds an organic or / and inorganic hydrophilic auxiliary agent containing -COOH, -OH, -CO and the like hydrophilic groups into the polypropylene filler to achieve the purpose of improving the hydrophilicity of the filler. At present, there is no related research results or commercial product records in various public documents or reports that realize the inhibition of the dioxin memory effect by adjusting or modifying the surface of the polypropylene filler.

[0023] The present application uses organic and inorganic hydrophilic auxiliary agents to modify the hydrophilicity of the polypropylene filler, reduces the adsorption of dioxins by the filler by reducing the contact angle (less than 90°) of the filler surface, and further reduces the desorption of dioxins. On the one hand, the larger spreading area of water on the filler can reduce the direct contact of the filler with the flue gas; on the other hand, water occupies the space in the gap inside the filler body, which can reduce the adsorption of dioxin hydrophobic solutes, thereby weakening the dioxin memory effect. Therefore, the present application realizes the reduction of the frequency of the occurrence of the dioxin memory effect or the reduction of the degree of the memory effect without affecting the removal efficiency of the acid pollutants and particulate matters in the wet system.

[0024] Compared with the prior art, the present application has the following advantages:

[0025] 1. The hydrophilic filler prepared by the present application can efficiently inhibit the adsorption and desorption of dioxins in the filler. Under the same use conditions, the adsorption and desorption inhibition efficiency of dioxins in the flue gas using the hydrophilic filler of the present application is up to 80% or more;

[0026] 2. The present application has the advantages of convenient operation and simple process, and does not need to adjust or modify the existing wet scrubbing system;

[0027] 3. The hydrophilic polypropylene filler prepared by the method has wide component sources and low price, and has important application value for solving the dioxin emission problem in waste incineration.

[0028] 4. The hydrophilic polypropylene filler prepared by the method has wide component sources and low price, and has important application value for solving the dioxin emission problem in waste incineration. DETAILED DESCRIPTION

[0029] The application will be further described in detail in combination with specific embodiments:

[0030] The first part is the implementation scheme of the application

[0031] The process for modifying the filler in the application is as follows:

[0032] The modified filler is prepared on a double-screw extruder. The raw material particles of the polypropylene base material are first mixed uniformly with the powdered or particulate hydrophilic aid, and then sent to the replenishment bin for standby. When the machine is started, the material is conveyed to the molten plasticizing zone by the conveying screw, and the temperature of the plasticizing zone is set to 230-240 DEG C. The molten injection plastic enters the mold through the nozzle, and then the three-dimensional structure of the modified filler is obtained after cooling and demolding. The modified filler has hydrophilic property, and the surface contact angle of the product is less than 90 DEG. The structure can be selected from any one of high-flow ring, flower ring, bower ring, hailer ring or conjugate ring.

[0033] The polypropylene base material is preferably random copolymerized polypropylene. The hydrophilic aid is at least one of an organic hydrophilic aid or an inorganic hydrophilic aid; wherein the organic hydrophilic aid contains at least one hydrophilic group of -COOH, -OH and -CO, and can be at least one of polyvinylpyrrolidone, maleic anhydride grafted polypropylene, ethylene-acrylic acid copolymer, maleic acid-acrylic acid copolymer, ethylene-vinyl alcohol copolymer and hydroxyethyl methyl cellulose. The inorganic hydrophilic aid is at least one of silicon dioxide, talc powder and glass fiber.

[0034] In the entire mixed injection material, the mass content of the polypropylene base material is 66.5-98.0 wt.%, and the mass content of the hydrophilic aid is 2.0-33.5 wt.% to ensure the blending effect of the materials.

[0035] The second part is the comparative example and the embodiment

[0036] The application of the existing commercial filler and the filler of the application will be compared in combination with the comparative example and the embodiment.

[0037] The dioxin desorption amount data of the fillers of each pair of proportion and embodiment were tested under the same use conditions for technical effect comparison: the reaction system was a small wet platform, 10 g / day of fly ash was added to the small wet platform as the system dioxin input source, and the fly ash used was the same batch of fly ash taken from the same solid waste incineration system; the commercial polypropylene fillers of each pair of proportion or the polypropylene fillers prepared in the embodiment were arranged in the wet scrubbing tower, and the heat desorption treatment was carried out in the same laboratory tube furnace heating mode, and the change of dioxin contained in the heat desorption flue gas was measured and recorded. The process conditions of heat desorption were as follows: the heating atmosphere was pure nitrogen, the heating temperature was 70°C, the gas flow was 0.5 L / min, and the heating time was 8 h.

[0038] 1. Commercial filler products in the prior art

[0039] Proportion 1:

[0040] The commercial polypropylene doughnut filler of DN50 model with pure random copolymer polypropylene base material and without hydrophilic modification had a surface contact angle of 101.7°. After running in the simulated wet tower environment for 16 days, the filler was heated in a 70°C nitrogen atmosphere, and the dioxin desorption amount was 70.09 fg I-TEQ / g·h.

[0041] Proportion 2:

[0042] The commercial polypropylene high-flow ring filler of DN50 model with pure random copolymer polypropylene base material and without hydrophilic modification had a surface contact angle of 97.3°. After running in the simulated wet tower environment for 16 days, the filler was heated in a 70°C nitrogen atmosphere, and the dioxin desorption amount was 10.71 fg I-TEQ / g·h.

[0043] Proportion 3:

[0044] The commercial polypropylene conjugate ring filler of DN50 model with pure random copolymer polypropylene base material and without hydrophilic modification had a surface contact angle of 99.0°. After running in the simulated wet tower environment for 16 days, the filler was heated in a 70°C nitrogen atmosphere, and the dioxin desorption amount was 25.93 fg I-TEQ / g·h.

[0045] Proportion 4:

[0046] The commercial polypropylene Helix ring filler of DN50 model with pure random copolymer polypropylene base material and without hydrophilic modification had a surface contact angle of 107.5°. After running in the simulated wet tower environment for 16 days, the filler was heated in a 70°C nitrogen atmosphere, and the dioxin desorption amount was 82.16 fg I-TEQ / g·h.

[0047] Table 1 Application of commercial fillers in the wet scrubbing tower of the incineration system (contact angle and dioxin desorption amount)

[0048]

[0049] 2、The application embodiments and filler product application situations

[0050] Different components and shapes of fillers prepared according to the method of the present application were tested using the same experimental device and process conditions as in the comparative examples.

[0051] The proportions of the components in the following examples refer to the mass percentage content of the corresponding components in the modified filler mixture before injection molding. During injection molding, the temperature of the plasticizing zone was set to 230°C for Examples 1-7, 235°C for Examples 8-18, and 240°C for Examples 19-23.

[0052] Example 1:

[0053] A modified high-flow ring filler was prepared, with polyvinylpyrrolidone as the organic hydrophilic additive, at a proportion of 2.0 wt.%, and polypropylene at a proportion of 98.0 wt.%. The contact angle of the filler was 88.9°; after running in a simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 6.92 fg I-TEQ / g·h, which was 35.4% lower than the dioxin desorption amount of the same type of filler in Comparative Example 1, and significantly lower than the dioxin desorption amounts of the different types of fillers in the other comparative examples.

[0054] Example 2:

[0055] A modified high-flow ring filler was prepared, with polyvinylpyrrolidone as the organic hydrophilic additive, at a proportion of 10.0 wt.%, and polypropylene at a proportion of 90.0 wt.%. The contact angle of the filler was 83.9°; after running in a simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 4.66 fg I-TEQ / g·h, which was 56.2% lower than the dioxin desorption amount of the same type of filler in Comparative Example 1, and significantly lower than the dioxin desorption amounts of the different types of fillers in the other comparative examples.

[0056] Example 3:

[0057] A modified high-flow ring filler was prepared, with polyvinylpyrrolidone as the organic hydrophilic additive, at a proportion of 25.0 wt.%, and polypropylene at a proportion of 75.0 wt.%. The contact angle of the filler was 77.9°; after running in a simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 4.20 fg I-TEQ / g·h, which was 60.8% lower than the dioxin desorption amount of the same type of filler in Comparative Example 1, and significantly lower than the dioxin desorption amounts of the different types of fillers in the other comparative examples.

[0058] Example 4:

[0059] The modified high-flow ring filler was prepared, and the organic hydrophilic auxiliary agent was polyvinylpyrrolidone, accounting for 33.5 wt.%. The filler contact angle was 79.1°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 3.61 fg I-TEQ / g·h, which was 66.3% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount was significantly lower than that of the different types of fillers in other comparative examples.

[0060] Example 5: The modified high-flow ring filler was prepared, and the inorganic hydrophilic auxiliary agent was silicon dioxide, accounting for 2.0 wt.%. The filler contact angle was 81.0°; after running in the dioxin environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 5.17 fg I-TEQ / g·h, which was 51.7% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount was significantly lower than that of the different types of fillers in other comparative examples.

[0061] Example 6:

[0062] The modified high-flow ring filler was prepared, and the inorganic hydrophilic auxiliary agent was silicon dioxide, accounting for 3.5 wt.%. The filler contact angle was 89.5°; after running in the dioxin environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 6.55 fg I-TEQ / g·h, which was 38.8% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount was significantly lower than that of the different types of fillers in other comparative examples.

[0063] Example 7:

[0064] The modified high-flow ring filler was prepared, and the inorganic hydrophilic auxiliary agent was silicon dioxide, accounting for 5.0 wt.%. The filler contact angle was 87.3°; after running in the dioxin environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70°C was 7.33 fg I-TEQ / g·h, which was 31.6% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount was significantly lower than that of the different types of fillers in other comparative examples.

[0065] Example 8:

[0066] The modified high-flow ring filler is prepared, the organic hydrophilic additive is polyvinyl pyrrolidone, the proportion is 25.0 wt.%, and the proportion of polypropylene is 75.0 wt.%. The contact angle of the filler is 77.6°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70 DEG C is 4.23 fg I-TEQ / g.h, which is 60.5% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different types of fillers in other comparative examples.

[0067] In addition, the same polyvinyl pyrrolidone addition ratio and different plasticizing zone setting temperatures are used in the embodiment and example 3, it can be seen that the contact angle of the filler, the dioxin desorption amount and the dioxin desorption amount reduction rate of the two examples are very close, and the change of plasticizing temperature does not have obvious influence.

[0068] Example 9:

[0069] The modified high-flow ring filler is prepared, the organic hydrophilic additive is polyvinyl pyrrolidone (25.0 wt.%), and the proportion of polypropylene is 73.0 wt.%. The contact angle of the filler is 79.5°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70 DEG C is 3.44 fg I-TEQ / g.h, which is 67.9% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different types of fillers in other comparative examples.

[0070] Example 10:

[0071] The modified high-flow ring filler is prepared, the organic hydrophilic additive is polyvinyl pyrrolidone (25.0 wt.%) and maleic anhydride grafted polypropylene (2.0 wt.%), and the proportion of polypropylene is 73.0 wt.%. The contact angle of the filler is 81.0°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in a nitrogen atmosphere at 70 DEG C is 3.42 fg I-TEQ / g.h, which is 68.1% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different types of fillers in other comparative examples.

[0072] Example 11:

[0073] The modified high-flow ring filler is prepared, the organic hydrophilic auxiliary agent is polyvinyl pyrrolidone (25.0wt.%) and ethylene-acrylic acid copolymer (2.0wt.%), and the polypropylene accounts for 73.0wt.%. The contact angle of the filler is 83.6°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 3.88fg I-TEQ / g·h, which is reduced by 63.8% compared with the dioxin desorption amount of the same type filler in the comparative example 1, and the dioxin desorption amount is significantly lower than that of the different type fillers in the other comparative examples.

[0074] Example 12:

[0075] The modified high-flow ring filler is prepared, the organic hydrophilic auxiliary agent is polyvinyl pyrrolidone (25.0wt.%) and maleic acid-acrylic acid copolymer (2.0wt.%), and the polypropylene accounts for 73.0wt.%. The contact angle of the filler is 86.9°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 3.65fg I-TEQ / g·h, which is reduced by 65.9% compared with the dioxin desorption amount of the same type filler in the comparative example 1, and the dioxin desorption amount is significantly lower than that of the different type fillers in the other comparative examples.

[0076] Example 13:

[0077] The modified high-flow ring filler is prepared, the organic hydrophilic auxiliary agent is polyvinyl pyrrolidone (25.0wt.%) and hydroxyethyl methyl cellulose (2.0wt.%), and the polypropylene accounts for 73.0wt.%. The contact angle of the filler is 82.4°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 4.09fg I-TEQ / g·h, which is reduced by 61.8% compared with the dioxin desorption amount of the same type filler in the comparative example 1, and the dioxin desorption amount is significantly lower than that of the different type fillers in the other comparative examples.

[0078] Example 14:

[0079] The modified high-flow ring filler is prepared, the organic hydrophilic auxiliary agent is polyvinyl pyrrolidone (25.0wt.%) and hydroxyethyl methyl cellulose (2.0wt.%), and the polypropylene accounts for 73.0wt.%. The contact angle of the filler is 82.4°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 4.09fg I-TEQ / g·h, which is reduced by 61.8% compared with the dioxin desorption amount of the same type filler in the comparative example 1, and the dioxin desorption amount is significantly lower than that of the different type fillers in the other comparative examples.

[0080] Example 15:

[0081] The modified high-flow ring filler is prepared, the organic hydrophilic aid is polyvinyl pyrrolidone (25.0 wt. %), the inorganic hydrophilic aid is talc (2.0 wt. %), and the polypropylene is 73.0 wt. %. The contact angle of the filler is 78.4°; after running in the simulated wet tower environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 3.22 fg I-TEQ / g·h, which is 69.9% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different types of fillers in other comparative examples.

[0082] Example 16:

[0083] The modified high-flow ring filler is prepared, the organic hydrophilic aid is polyvinyl pyrrolidone (25.0 wt. %), the inorganic hydrophilic aid is talc (2.0 wt. %), and the polypropylene is 73.0 wt. %. The contact angle of the filler is 78.4°; after running in the simulated wet tower environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 3.22 fg I-TEQ / g·h, which is 69.9% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different types of fillers in other comparative examples.

[0084] Example 17:

[0085] The modified high-flow ring filler is prepared, the organic hydrophilic aid is polyvinyl pyrrolidone (25.0 wt. %), the inorganic hydrophilic aid is talc (2.0 wt. %), and the polypropylene is 73.0 wt. %. The contact angle of the filler is 78.4°; after running in the simulated wet tower environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70°C is 3.22 fg I-TEQ / g·h, which is 69.9% lower than that of the same type of filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different types of fillers in other comparative examples.

[0086] Example 18:

[0087] The modified high-flow ring filler is prepared, the organic hydrophilic additive is polyvinyl pyrrolidone (25.0 wt.%), ethylene-vinyl alcohol copolymer (1.0 wt.%), maleic anhydride grafted polypropylene (1.0 wt.%), the inorganic hydrophilic additive is silicon dioxide (2.0 wt.%), talc (1.0 wt.%), glass fiber (1.0 wt.%), and the polypropylene accounts for 69.0 wt.%. The contact angle of the filler is 70.6°; after running in the simulated wet tower environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70 DEG C is 1.88 fg I-TEQ / g·h, which is reduced by 82.4% compared with the dioxin desorption amount of the same type filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different type fillers in other comparative examples.

[0088] Example 19:

[0089] The modified high-flow ring filler is prepared, the organic hydrophilic additive is polyvinyl pyrrolidone (25.0 wt.%), ethylene-vinyl alcohol copolymer (1.0 wt.%), maleic anhydride grafted polypropylene (1.0 wt.%), the inorganic hydrophilic additive is silicon dioxide (2.0 wt.%), talc (1.0 wt.%), glass fiber (1.0 wt.%), and the polypropylene accounts for 69.0 wt.%. The contact angle of the filler is 70.9°; after running in the simulated wet tower environment for 16 days, the dioxin desorption amount of the filler heated in the nitrogen atmosphere at 70 DEG C is 1.85 fg I-TEQ / g·h, which is reduced by 82.7% compared with the dioxin desorption amount of the same type filler in Comparative Example 1, and the dioxin desorption amount is significantly lower than that of the different type fillers in other comparative examples.

[0090] In addition, the same polyvinyl pyrrolidone addition ratio and different plasticizing zone setting temperature are used in the present embodiment and Example 18, it can be seen that the contact angle, dioxin desorption amount and dioxin desorption amount reduction rate of the fillers of the two examples are very close, and the change of plasticizing temperature does not have obvious effect.

[0091] Example 20:

[0092] The modified wreath filler is prepared, the organic hydrophilic aid is polyvinyl pyrrolidone (25.0wt.%), ethylene-vinyl alcohol copolymer (1.0wt.%), maleic anhydride grafted polypropylene (1.0wt.%), the inorganic hydrophilic aid is silicon dioxide (2.0wt.%), talcum powder (1.0wt.%), glass fiber (1.0wt.%), and the polypropylene accounts for 69.0wt.%. The filler contact angle is 73.9°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated by 70 DEG C nitrogen atmosphere is 8.69fg I-TEQ / g·h, which is reduced by 87.6% compared with the dioxin desorption amount of the same type filler in comparative example 2, and the dioxin desorption amount is obviously lower than that of different types of fillers in other comparative examples.

[0093] Example 21:

[0094] The modified wreath filler is prepared, the organic hydrophilic aid is polyvinyl pyrrolidone (25.0wt.%), ethylene-vinyl alcohol copolymer (1.0wt.%), maleic anhydride grafted polypropylene (1.0wt.%), the inorganic hydrophilic aid is silicon dioxide (2.0wt.%), talcum powder (1.0wt.%), glass fiber (1.0wt.%), and the polypropylene accounts for 69.0wt.%. The filler contact angle is 73.9°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated by 70 DEG C nitrogen atmosphere is 8.69fg I-TEQ / g·h, which is reduced by 87.6% compared with the dioxin desorption amount of the same type filler in comparative example 2, and the dioxin desorption amount is obviously lower than that of different types of fillers in other comparative examples.

[0095] Example 21:

[0096] The modified wreath filler is prepared, the organic hydrophilic aid is polyvinyl pyrrolidone (25.0wt.%), ethylene-vinyl alcohol copolymer (1.0wt.%), maleic anhydride grafted polypropylene (1.0wt.%), the inorganic hydrophilic aid is silicon dioxide (2.0wt.%), talcum powder (1.0wt.%), glass fiber (1.0wt.%), and the polypropylene accounts for 69.0wt.%. The filler contact angle is 73.9°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler heated by 70 DEG C nitrogen atmosphere is 8.69fg I-TEQ / g·h, which is reduced by 87.6% compared with the dioxin desorption amount of the same type filler in comparative example 2, and the dioxin desorption amount is obviously lower than that of different types of fillers in other comparative examples.

[0097] Example 21:

[0098] The modified Hayduck ring filler is prepared, the organic hydrophilic additive is polyvinyl pyrrolidone (25.0 wt. %), ethylene-vinyl alcohol copolymer (1.0 wt. %), maleic anhydride grafted polypropylene (1.0 wt. %), the inorganic hydrophilic additive is silicon dioxide (2.0 wt. %), talc (1.0 wt. %), glass fiber (1.0 wt. %), and the polypropylene accounts for 69.0 wt. %. The filler contact angle is 76.1°; after running in the simulated wet column environment for 16 days, the dioxin desorption amount of the filler is 9.12 fg I-TEQ / g·h under the condition of heating the filler in a nitrogen atmosphere at 70 DEG C, which is reduced by 88.9% compared with the dioxin desorption amount of the same type of filler in Comparative Example 5, and the dioxin desorption amount is significantly lower than that of the fillers of different types in other comparative examples.

[0099] Table 2 dioxin desorption amount reduction ratio of hydrophilic modified filler with different proportions

[0100]

[0101] From the above experimental data, it can be seen that the modified filler of the present application has a dioxin desorption amount far lower than that of the same type of commercial filler product when used in the wet scrubbing process of waste incineration flue gas in the wet scrubbing tower after greatly changing the process conditions. The reason for this technical difference is that the present application forms a surface contact angle of less than 90° on the surface of the polypropylene substrate through hydrophilic modification, so that the modified filler itself has hydrophilic property; the change of plasticizing temperature has little effect on the contact angle and other data, and the main influencing factor is the difference of hydrophilic additive. Compared with the filler made of the existing commercial polypropylene material, the hydrophilic modified filler technology of the present application can synergistically increase the contact efficiency of flue gas and circulating water, and efficiently inhibit the adsorption and desorption process of dioxin on the filler. Moreover, the filler preparation method of the present application is simple in operation and low in running cost, and has great application value in future waste incineration disposal.

[0102] Finally, it should be noted that the above enumeration is only a specific embodiment of the present application. Obviously, the present application is not limited to the above embodiment, but can have many variations. All variations that can be directly derived or inferred from the disclosure of the present application by those skilled in the art should be considered as falling within the scope of protection of the present application.

Claims

1. A modified filler capable of effectively inhibiting dioxin adsorption and desorption, characterized in that: The modified filler is obtained by injection molding a mixture of a polypropylene base material and a hydrophilic additive; The modified filler is hydrophilic, and the surface contact angle of the product is less than 90°; The polypropylene base material is random copolymer polypropylene; The hydrophilic additive is at least one of an organic hydrophilic additive or an inorganic hydrophilic additive; wherein, The organic hydrophilic additive is at least one of polyvinyl pyrrolidone, ethylene-acrylic acid copolymer, maleic acid-acrylic acid copolymer, ethylene-vinyl alcohol copolymer, and hydroxyethyl methylcellulose, and the organic hydrophilic additive contains at least one hydrophilic group selected from -COOH, -OH, and -CO; The inorganic hydrophilic additive is at least one of silicon dioxide, talc, and glass fiber; In the mixture, the mass content of the polypropylene base material is 66.5-98.0 wt.%, and the mass content of the hydrophilic additive is 2.0-33.5 wt.%.

2. The modified filler according to claim 1, characterized in that The modified filler has a structural shape of any one of a high flow ring, a rosette, a ball ring, a Haier ring or a conjugated ring.

3. The method for preparing the modified filler according to claim 1, characterized in that: The following steps are involved: (1) Weigh the polypropylene base material and the hydrophilic additive according to the mass percentage relationship and mix them evenly; (2) The uniform mixture is added into the hopper of the injection molding machine, and a modified filler product with a three-dimensional structure is obtained through the injection molding process.

4. The method according to claim 3, characterized in that During injection molding, set the temperature of the plasticizing zone of the injection molding machine to 230~240℃.

5. The method according to claim 3, characterized in that The hydrophilic auxiliary agent is in powder or granular form.

6. The method according to claim 3, characterized in that The hydrophilic adjuvant contains at least one of silicon dioxide and polyvinyl pyrrolidone.

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