RDF combustion rod based on municipal solid waste and preparation method thereof

Abstract

The invention relates to an RDF combustion rod based on municipal solid waste and a preparation method thereof, and the preparation method comprises the following steps: selecting municipal solid waste with a calorific value, and carrying out low-temperature drying-microwave modification pretreatment to obtain pretreated domestic waste; sequentially carrying out primary crushing, sorting, impurity removal and crushing on the pretreated household garbage to obtain a crushed material; performing high-temperature activation on bentonite to obtain high-temperature activated bentonite; soaking sepiolite with a fibrous structure in a hydrochloric acid solution, washing with water until the sepiolite is neutral, and drying to obtain modified sepiolite; and carrying out high-temperature roasting-ultrasonic dispersion treatment on sludge gasification slag to obtain pretreated sludge gasification slag, mixing the pretreated sludge gasification slag with the crushed material, high-temperature activated bentonite and modified sepiolite, and carrying out pressure forming to obtain the RDF combustion rod. Municipal solid waste with a calorific value is pretreated, so that the reaction activity is improved; and the pretreated sludge gasification slag is used as a catalyst, so that the combustion performance of the RDF combustion rod is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, specifically relating to an RDF combustion rod based on municipal solid waste and its preparation method. Background Technology

[0002] With development, the amount of urban domestic waste is gradually increasing, and the composition of urban domestic waste is constantly changing. The traditional management model of landfilling as the main method of waste disposal will be transformed. From the perspective of protecting the natural environment and ecological balance, maximizing the resource utilization of waste treatment while ensuring the harmlessness of waste treatment has become a new trend. From the perspective of environmental science, direct incineration is prone to unstable combustion conditions due to the high heterogeneity of waste composition, which in turn produces persistent organic pollutants such as dioxins and furans, making it difficult to meet the strict requirements of the "Standard for Pollution Control of Municipal Solid Waste Incineration" (GB-18485-2014). Under this technical bottleneck, Refuse-derived fuel (RDF) as a new treatment technology based on the principle of solid waste fractional utilization provides a scientific solution to the above contradictions.

[0003] Municipal solid waste contains many components with calorific value, such as straw, manure, wood, plastics, rubber, paper products, kitchen waste, textiles, and coal, which have the characteristics to be used to prepare alternative fuels. Therefore, the calorific value components of municipal solid waste can be made into waste-derived fuels. As a new type of renewable energy material, waste-derived fuels have broad development prospects and huge market demand in the field of energy conservation and emission reduction. It is an applicable technology to realize the energy conversion of waste and achieve the best comprehensive benefits. It can also replace some traditional fossil fuels and promote the sustainable development of clean energy technologies in the future, thereby reducing carbon emissions and improving efficiency.

[0004] Waste-derived fuel (RDF) is a key form of resource utilization of municipal solid waste, and its combustion performance directly determines the efficiency and economy of energy recovery. How to optimize the pretreatment process of RDF raw materials and additives, and screen synergistic functional materials to achieve efficient combustion and energy release is a current research hotspot and challenge. To this end, this invention proposes an RDF combustion rod based on municipal solid waste and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide an RDF combustion rod based on municipal solid waste and its preparation method in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions: This invention provides a method for preparing RDF combustion rods based on municipal solid waste, comprising the following steps: Step 1: Sorting municipal solid waste and selecting municipal solid waste with calorific value for low-temperature drying-microwave modification pretreatment to obtain pretreated municipal solid waste; Step 2: The pre-treated municipal solid waste is subjected to initial crushing, sorting and impurity removal, and pulverization in sequence to obtain pulverized material; Step 3: The bentonite is activated at high temperature to obtain high-temperature activated bentonite; Step 4: The fibrous sepiolite is soaked in hydrochloric acid solution, washed with water until neutral, and dried to obtain modified sepiolite; Step 5: The sludge gasification slag is pretreated by high-temperature roasting and ultrasonic dispersion. It is then mixed with the crushed material, high-temperature activated bentonite, and modified sepiolite, and then prepared into RDF combustion rods by pressure molding.

[0007] As a further optimization of the present invention, in step one, the urban domestic waste with calorific value includes straw, feces, wood, plastic, rubber, paper products, kitchen waste, cloth and coal. The low-temperature drying-microwave modification pretreatment specifically involves drying the municipal solid waste with calorific value at 100-120℃ for 4-6 hours to control its moisture content to ≤15%, and then modifying it with microwave at 2450MHz and 300-500W for 3-5 minutes.

[0008] As a further optimization of the present invention, in step two, the output particle size of the initial crushing is 20-100mm; the sorting and impurity removal includes at least one of magnetic separation and air separation; the ash content after sorting and impurity removal is <10%; and the particle size of the pulverized material is 3-8mm.

[0009] As a further optimization of the present invention, in step three, the high-temperature activation is to select bentonite with a montmorillonite content ≥85% and activate it at a high temperature of 500-600℃ for 2-3 hours.

[0010] As a further optimization of the present invention, in step four, the method for obtaining the modified sepiolite is as follows: sepiolite with a fibrous structure morphology of ≥90% is selected, soaked in 1mol / L hydrochloric acid solution for 4-6 hours, washed with water until neutral, and then dried at 105℃ for 3 hours.

[0011] As a further optimization of the present invention, in step five, the high-temperature roasting-ultrasonic dispersion treatment of the sludge gasification residue is specifically performed by first roasting at 800-900℃ for 2-3 hours, and then ultrasonically dispersing at 20-30kHz for 30-60 minutes. The particle size of the pretreated sludge gasification residue is 200-400 mesh.

[0012] As a further optimization of the present invention, in step five, the total amount of the high-temperature activated bentonite and modified sepiolite added is 3-8% of the mass of the crushed material, and the mass ratio of the high-temperature activated bentonite to the modified sepiolite is (1-2):(1-2). The amount of pretreated sludge gasification residue added is 3-15% of the mass of the crushed material.

[0013] As a further optimization of the present invention, in step five, the mixing process is as follows: first, the crushed material is mixed with the pretreated sludge gasification residue for 15-20 minutes, and then high-temperature activated bentonite and modified sepiolite are added and mixed for another 20-25 minutes, with a mixing uniformity ≥95%.

[0014] As a further optimization of the present invention, in step five, the length, width, and height dimensions of the RDF combustion rod are (1-4) cm × (1-3) cm × (1-10) cm, and the compaction density is 0.80-1.50 g / cm³. 3 .

[0015] The present invention also provides an RDF combustion rod based on municipal solid waste, which is prepared by the preparation method described above.

[0016] The beneficial effects of this invention are as follows: 1) This invention pre-treats municipal solid waste with calorific value through "low-temperature drying-microwave modification", which not only removes excess moisture to avoid heat loss during combustion, but also destroys the inert structure of organic components through microwave action, thereby improving reaction activity. This invention uses sludge gasification residue as a catalyst, and after the sludge gasification residue is pre-treated by "high-temperature roasting-ultrasonic dispersion", the catalytic active components are activated, the particle size distribution is more uniform, the catalytic efficiency is significantly improved, and the combustion performance of RDF combustion rods is significantly improved.

[0017] 2) This invention selects two special non-combustible soil materials, natural bentonite and sepiolite, and achieves functional synergy after targeted pretreatment. High-temperature activated bentonite has excellent adsorption performance and structural stability, and can adsorb some harmful substances generated during combustion, while optimizing the internal pore structure of the RDF combustion rod. The fibrous structure of modified sepiolite can enhance the mechanical strength of the fuel rod, and its well-developed pore system can enhance oxygen diffusion and heat transfer. Together with the pretreated sludge gasification slag catalyst, it forms a synergistic system of "catalytic combustion-pore optimization-mass transfer enhancement", further improving the combustion performance of the RDF combustion rod. 3) Based on municipal solid waste, this invention explores the performance of RDF through pretreatment of raw materials, screening and modification of special functional materials, and their synergistic design, pointing out the research direction for improving the performance of waste-derived fuels. Attached Figure Description

[0018] Figure 1 This is a comparison diagram of the sludge gasification slag in Embodiment 8 of the present invention before and after pretreatment.

[0019] Figure 2 This is a sample image of the formed RDF combustion rod of Embodiment 8 of the present invention. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0021] I. Materials 1. The urban domestic waste with calorific value in this invention includes straw, feces, wood, plastics, rubber, paper products, kitchen waste, cloth, and coal; 2. Sludge gasification slag from municipal wastewater treatment plants: Its main components are oxygen-rich mineral phases such as CaO, Fe2O3, Al2O3, and SiO2, and it contains abundant surface active sites and metal ion catalytic centers. In this invention, 6 groups of samples were collected, and the composition of each group of samples is shown in Table 1. The experiment of this invention uses the following 6 groups of samples after uniform mixing in equal amounts. Table 1. Composition of Sludge Gasification Ash ; 3. Bentonite: Bentonite with a montmorillonite content ≥ 85%, and the bentonite used in the following experiments of this invention is bentonite with a montmorillonite content of 87.6%; 4. Sepiolite: Sepiolite with a fibrous structure ≥ 90%; the sepiolite used in the following experiments of this invention is sepiolite with a fibrous structure ≥ 91.5%. Unless otherwise specified, all methods used in this application are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products unless otherwise specified.

[0022] II. Methods Example 1 In this embodiment, an RDF combustion rod based on municipal solid waste is provided, the raw materials for which include municipal solid waste with calorific value, pretreated sludge gasification slag, bentonite, and modified sepiolite. The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Sepiolite with a fibrous structure content of 91.5% was soaked in 1 mol / L hydrochloric acid solution for 5 h with a solid-liquid ratio of 1:10, washed with water until neutral, and then dried at 105℃ for 3 h to obtain modified sepiolite. (4) Take the sludge gasification slag from the municipal sewage treatment plant, calcine it at 850℃ for 2.5h, and then ultrasonically disperse it at 25kHz for 45min to obtain pretreated sludge gasification slag with a particle size of 200 mesh. The amount of the pretreated sludge gasification slag added is 3-15% of the mass of the crushed material (in this embodiment, the amount added is 3% of the mass of the crushed material). Mix the crushed material with the 200 mesh pretreated sludge gasification slag for 18min. Take bentonite and the modified sepiolite obtained in step (3) above, mix them at a mass ratio of 1:1 to obtain a soil material mixture. Then add the non-combustible soil material mixture into the crushed material (the amount of the non-combustible soil material mixture added is 3-8% of the mass of the crushed material. In this embodiment, the amount added is 3% of the mass of the crushed material). Continue to stir and mix for 22min. The mixing uniformity is 96.5%. After mixing, the RDF granulator is used to extrude and mold the RDF combustion rod. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0023] Example 2 In this embodiment, an RDF combustion rod based on municipal solid waste is provided, the raw materials for which include municipal solid waste with calorific value, pretreated sludge gasification slag, high-temperature activated bentonite, and sepiolite. The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Bentonite with a montmorillonite content of 87.6% was activated at 500℃ for 2.5h to obtain high-temperature activated bentonite; (4) Take the sludge gasification slag from the municipal sewage treatment plant, calcine it at 850℃ for 2.5h, and then ultrasonically disperse it at 25kHz for 45min to obtain pretreated sludge gasification slag with a particle size of 200 mesh. The amount of the pretreated sludge gasification slag added is 3-15% of the mass of the crushed material (in this embodiment, the amount added is 3% of the mass of the crushed material). Mix the crushed material with the 200 mesh pretreated sludge gasification slag for 18min. Take the high-temperature activated bentonite and sepiolite obtained in step (3) above, mix them at a mass ratio of 1:1 to obtain a soil material mixture. Then add the non-combustible soil material mixture into the crushed material (the amount of the non-combustible soil material mixture added is 3-8% of the mass of the crushed material. In this embodiment, the amount added is 3% of the mass of the crushed material). Continue to stir and mix for 22min. The mixing uniformity is 96.5%. After mixing, the RDF granulator is used to extrude and mold the mixture to obtain RDF combustion rods. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0024] Example 3 In this embodiment, an RDF combustion rod based on municipal solid waste is provided. The raw materials for its preparation include municipal solid waste with calorific value, pretreated sludge gasification slag, high-temperature activated bentonite, and modified sepiolite. The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Bentonite with a montmorillonite content of 87.6% was activated at 500℃ for 2.5h to obtain high-temperature activated bentonite; (4) Sepiolite with a fibrous structure content of 91.5% was soaked in 1 mol / L hydrochloric acid solution for 5 h with a solid-liquid ratio of 1:10, washed with water until neutral, and then dried at 105℃ for 3 h to obtain modified sepiolite. (5) The sludge gasification slag from the municipal sewage treatment plant is calcined at 850℃ for 2.5h and ultrasonically dispersed at 25kHz for 45min to obtain pretreated sludge gasification slag with a particle size of 200 mesh. The amount of the pretreated sludge gasification slag added is 3-15% of the mass of the crushed material (in this embodiment, the amount added is 3% of the mass of the crushed material). The crushed material and the 200 mesh pretreated sludge gasification slag are stirred and mixed for 18min. The high-temperature activated bentonite obtained in step (3) and the modified sepiolite obtained in step (4) are mixed at a mass ratio of 1:1 to obtain a soil material mixture. The non-combustible soil material mixture is then added to the crushed material (the amount of the non-combustible soil material mixture added is 3-8% of the mass of the crushed material, in this embodiment, the amount added is 3% of the mass of the crushed material). The mixture is stirred and mixed for 22min. The mixing uniformity is 96.5%. After mixing, the mixture is extruded and molded by an RDF granulator to obtain RDF combustion rods. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0025] To investigate the effects of the mass ratio of high-temperature activated bentonite to modified sepiolite, the dosage of soil material mixture, and the dosage of pretreated sludge gasification slag on the performance of the final RDF burner, the present invention designed the technical solutions of Examples 4-9 as shown in Table 2: Table 2 Technical Solution Design of Examples 4-9 ; To investigate the effects of pretreated sludge gasification slag, high-temperature activated bentonite, and modified sepiolite on the performance of the final RDF combustion rod, this invention also designed the experimental designs of comparative examples 1-5 and a blank group as shown below: Comparative Example 1 In this comparative example, an RDF combustion rod based on municipal solid waste is provided, the raw materials for which include municipal solid waste with calorific value, pretreated sludge gasification slag, modified bentonite, and high-temperature activated sepiolite. The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Bentonite with 87.6% montmorillonite content was soaked in 1 mol / L hydrochloric acid solution for 5 h with a solid-liquid ratio of 1:10, washed with water until neutral, and then dried at 105℃ for 3 h to modify the bentonite. (4) High-temperature activated sepiolite was obtained by activating sepiolite with a fibrous structure content of 91.5% at 500℃ for 2.5h. (5) Take the sludge gasification slag from the municipal sewage treatment plant, calcine it at 850℃ for 2.5h, and then ultrasonically disperse it at 25kHz for 45min to obtain pretreated sludge gasification slag with a particle size of 200 mesh. The amount of the pretreated sludge gasification slag added is 10% of the mass of the crushed material. Mix the crushed material with the 200 mesh pretreated sludge gasification slag for 18min. Take the modified bentonite obtained in step (3) and the high-temperature activated sepiolite obtained in step (4) above, mix them at a mass ratio of 1:1 to obtain a soil material mixture. Then add the non-combustible soil material mixture into the crushed material (the amount of the non-combustible soil material mixture added is 5% of the mass of the crushed material), continue to stir and mix for 22min, and the mixing uniformity is 96.5%. After mixing, extrude the mixture through an RDF granulator to obtain RDF combustion rods. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0026] Comparative Example 2 In this comparative example, an RDF combustion rod based on municipal solid waste is provided. The difference from Example 8 is that ordinary garden soil is used to replace bentonite and sepiolite in equal amounts for high-temperature activation and modification treatment; otherwise, it is consistent with Example 8.

[0027] Comparative Example 3 In this comparative example, an RDF combustion rod based on municipal solid waste is provided, the raw materials for which include municipal solid waste with calorific value and sludge gasification slag. The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Take sludge gasification slag from municipal sewage treatment plant, disperse it with ultrasonic at 25 kHz for 45 min to obtain sludge gasification slag with a particle size of 200 mesh. The amount of sludge gasification slag added is 10% of the mass of the crushed material. Mix the crushed material with the 200 mesh sludge gasification slag for 40 min. The mixing uniformity is 96.5%. After mixing, the RDF granulator is used to extrude and form RDF combustion rods. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0028] Comparative Example 4 In this comparative example, an RDF combustion rod based on municipal solid waste is provided, the raw materials for which include municipal solid waste with calorific value and pretreated sludge gasification slag. The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Take sludge gasification slag from municipal sewage treatment plant, roast it at 850℃ for 2.5h, and then ultrasonically disperse it at 25kHz for 45min to obtain pretreated sludge gasification slag with a particle size of 200 mesh. The amount of pretreated sludge gasification slag added is 10% of the mass of the crushed material. Mix the crushed material with the 200 mesh pretreated sludge gasification slag for 40min. The mixing uniformity is 96.5%. After mixing, the RDF granulator is used to extrude and form RDF combustion rods. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0029] Comparative Example 5 In this comparative example, an RDF combustion rod based on municipal solid waste is provided, the raw materials for which include municipal solid waste with calorific value, high-temperature activated bentonite, and modified sepiolite; The specific steps of the preparation method of the RDF combustion rod based on municipal solid waste are as follows: (1) Select municipal solid waste with calorific value, dry it at 110℃ for 5 hours to make the moisture content 12%, and then modify it with microwave at 2450MHz and 400W for 4 minutes to obtain pretreated municipal solid waste; (2) The pretreated domestic waste obtained in step (1) is subjected to primary crushing by a dual-shaft shear shredder (discharge particle size is 60mm), magnetic separation to remove iron, wind separation to remove impurities at a wind speed of 6m / s (ash content is 8.62%), and pulverization by a single-shaft crusher (discharge particle size is 5mm) to obtain pulverized material; (3) Bentonite with a montmorillonite content of 87.6% was activated at 500℃ for 2.5h to obtain high-temperature activated bentonite; (4) Sepiolite with a fibrous structure content of 91.5% was soaked in 1 mol / L hydrochloric acid solution for 4-6 hours with a solid-liquid ratio of 1:10, washed with water until neutral, and then dried at 105℃ for 3 hours to obtain modified sepiolite. (5) The high-temperature activated bentonite obtained in step (3) and the modified sepiolite obtained in step (4) are mixed at a mass ratio of 1:1 to obtain a soil material mixture. The non-combustible soil material mixture is then added to the crushed material (the amount of the non-combustible soil material mixture added is 5% of the mass of the crushed material). The mixture is stirred for 40 minutes, and the uniformity of the mixture is 96.5%. After mixing, the mixture is extruded and molded by an RDF granulator to obtain an RDF combustion rod. It should be noted that, in this embodiment, the RDF combustion rod has dimensions of 1cm × 1.1cm × 5cm and a compaction density of 1 ± 0.1g / cm³. 3 .

[0030] III. Experimental Testing To compare the combustion performance of the RDF combustion rods of Examples 1-9 and Comparative Examples 1-5, the present invention conducted the following experiments, as detailed below: (1) Calorific value (kcal / kg) According to standard GB / T-30727-2014 "Determination of Calorific Value of Solid Biomass Fuels"; Experimental equipment: oxygen bomb calorimeter, precision electronic balance (accuracy 0.0001g), forced-air drying oven; Experimental conditions: Sample pretreatment: RDF combustion rods were crushed to a particle size ≤1mm and dried at 105℃ to constant weight to eliminate the influence of moisture; 1-1.2g of sample was weighed and placed in an oxygen bomb, and oxygen was added to a pressure of 2.8-3.0MPa; the oxygen bomb calorimetry method was followed to determine the water temperature change and calculate the higher heating value (1kcal / kg=4.1868kJ / kg).

[0031] (2) Combustion activation energy (kJ / mol) According to the standard GB / T-38303-2019 "Thermogravimetric Analysis - Determination of Thermal Stability of Materials"; Experimental equipment: thermogravimetric analyzer; Experimental conditions: Sample pretreatment: Grind the RDF combustion rod to a particle size <100 mesh and weigh 15±0.5mg of sample; Equipment parameters: Atmosphere: air (oxygen content 21%), gas flow rate 50mL / min; Heating rate: 20℃ / min, heating range: room temperature to 900℃; Data processing: Activation energy of combustion reaction was calculated using the Kissinger method based on thermogravimetric (TG) curves.

[0032] (3) Combustion rate (min / kg) According to the standard: refer to the combustion test section of GB / T-16157-1996 "Determination of Particulate Matter and Sampling Methods for Gaseous Pollutants in Exhaust Gas from Stationary Sources"; Experimental equipment: small fixed-bed combustion test bench, electronic balance (accuracy 0.1g), temperature controller; Experimental conditions: Take a 100g RDF combustion rod and place it in a fixed-bed furnace while maintaining its original size. Control the furnace temperature at 850℃ and the excess air coefficient at 1.2. Record the time from ignition of the sample to complete combustion. Combustion rate = sample mass (kg) / combustion time (min). Take the average value of 3 parallel samples as the experimental data.

[0033] (4) NO x Emission concentration (mg / m³) 3 (24-hour average) According to the standard: GB / T-16157-1996 "Determination of Particulate Matter and Sampling Methods for Gaseous Pollutants in Exhaust Gas from Stationary Sources"; Experimental equipment: constant potential electrolysis flue gas analyzer, flue gas sampling gun; Experimental conditions: Simulating actual combustion conditions: RDF burners were continuously fed into the combustion furnace, with the furnace temperature controlled at 850℃ and the excess air coefficient at 1.2; flue gas was collected according to GB / T16157-1996, continuously sampled for 24 hours, and NO was measured once per hour. x Concentration; calculate the arithmetic mean of 24 measurements, which is the 24-hour average.

[0034] (5) Dioxin emission concentration (ngTEQ / m³) 3 ) According to the standard: HJ-77.2-2008 "Determination of dioxins in ambient air and exhaust gas by isotope dilution high-resolution gas chromatography-high-resolution mass spectrometry"; Experimental equipment: High-resolution gas chromatography-high-resolution mass spectrometry (HRGC-HRMS), flue gas sampling device, rotary evaporator; Experimental conditions: Sampling: Combustion flue gas was collected according to HJ-77.2-2008, with a sampling volume ≥4m³ under standard conditions. 3 Sample pretreatment: Extract, purify, and concentrate the adsorbed sample, and add... 13 C-labeled dioxin internal standard; Detection: 17 2,3,7,8-chlorodioxins were analyzed by HRGC-HRMS, and the final concentration was calculated in toxicity equivalent (TEQ).

[0035] The experimental data obtained from the above experiments are all recorded in Table 3: Table 3 Experimental data on the combustion performance of RDF burners ; Experimental conclusions: In this invention, municipal solid waste with calorific value is pretreated by "low-temperature drying-microwave modification," which not only removes excess moisture to avoid heat loss during combustion, but also destroys the inert structure of organic components through microwave action, thereby improving reaction activity. Furthermore, based on the data analysis in Table 3, it can be seen that this invention uses sludge gasification residue as a catalyst, and after the sludge gasification residue is pretreated by "high-temperature calcination-ultrasonic dispersion," the catalytically active components are activated, the particle size distribution is more uniform, the catalytic efficiency is significantly improved, and the combustion performance of the RDF combustion rod is significantly enhanced. This invention selects two special non-combustible soil materials, natural bentonite and sepiolite, and achieves synergistic function after targeted pretreatment. High-temperature activated bentonite has excellent adsorption performance and structural stability, and can adsorb some harmful substances generated during combustion, while optimizing the internal pore structure of the RDF burner. The fibrous structure of modified sepiolite can enhance the mechanical strength of the fuel rod, and its well-developed pore system can enhance oxygen diffusion and heat transfer. Together with the pretreated sludge gasification slag catalyst, it forms a synergistic system of "catalytic combustion-pore optimization-mass transfer enhancement", further improving the combustion performance of the RDF burner.

[0036] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing an RDF combustion rod based on municipal solid waste, characterized in that: Includes the following steps: Step 1: Sorting municipal solid waste and selecting municipal solid waste with calorific value for low-temperature drying-microwave modification pretreatment to obtain pretreated municipal solid waste; Step 2: The pre-treated municipal solid waste is subjected to initial crushing, sorting and impurity removal, and pulverization in sequence to obtain pulverized material; Step 3: The bentonite is activated at high temperature to obtain high-temperature activated bentonite; Step 4: The fibrous sepiolite is soaked in hydrochloric acid solution, washed with water until neutral, and dried to obtain modified sepiolite; Step 5: The sludge gasification slag is pretreated by high-temperature roasting and ultrasonic dispersion. It is then mixed with the crushed material, high-temperature activated bentonite, and modified sepiolite, and then prepared into RDF combustion rods by pressure molding.

2. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step one, the municipal solid waste with calorific value includes straw, feces, wood, plastic, rubber, paper products, kitchen waste, cloth, and coal; The low-temperature drying-microwave modification pretreatment specifically involves drying the municipal solid waste with calorific value at 100-120℃ for 4-6 hours to control its moisture content to ≤15%, and then modifying it with microwave at 2450MHz and 300-500W for 3-5 minutes.

3. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step two, the output particle size of the initial crushing is 20-100mm; the sorting and impurity removal includes at least one of magnetic separation and air separation; the ash content after sorting and impurity removal is <10%; and the particle size of the pulverized material is 3-8mm.

4. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step three, the high-temperature activation involves selecting bentonite with a montmorillonite content ≥85% and activating it at 500-600℃ for 2-3 hours.

5. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step four, the method for obtaining the modified sepiolite is as follows: sepiolite with a fibrous structure ≥90% is selected, soaked in 1mol / L hydrochloric acid solution for 4-6 hours, washed with water until neutral, and then dried at 105℃ for 3 hours.

6. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step five, the high-temperature roasting-ultrasonic dispersion treatment of the sludge gasification residue specifically involves first roasting at 800-900℃ for 2-3 hours, and then ultrasonically dispersing at 20-30kHz for 30-60 minutes. The particle size of the pretreated sludge gasification residue is 200-400 mesh.

7. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step five, the total amount of the high-temperature activated bentonite and modified sepiolite added is 3-8% of the mass of the crushed material, and the mass ratio of the high-temperature activated bentonite to the modified sepiolite is (1-2):(1-2). The amount of pretreated sludge gasification residue added is 3-15% of the mass of the crushed material.

8. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step five, the mixing process involves first mixing the pulverized material with the pretreated sludge gasification residue for 15-20 minutes, then adding high-temperature activated bentonite and modified sepiolite and continuing to mix for 20-25 minutes, with a mixing uniformity ≥95%.

9. The method for preparing an RDF combustion rod based on municipal solid waste according to claim 1, characterized in that: In step five, the length, width, and height dimensions of the RDF combustion rod are (1-4) cm × (1-3) cm × (1-10) cm, and the compaction density is 0.80-1.50 g / cm³. 3 .

10. An RDF incineration rod based on municipal solid waste, characterized in that: It is prepared by any one of the preparation methods described in claims 1-9.

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