Low-temperature pyrolysis household garbage waste gas treatment method

Abstract

The invention discloses a low-temperature pyrolysis household garbage waste gas treatment method which comprises the following steps: inputting household garbage into a low-temperature pyrolysis reactor, carrying out pyrolysis treatment in a temperature range of 300-500 DEG C, introducing air to be mixed with waste gas in the pyrolysis process so as to primarily dilute harmful substances in the waste gas, and introducing the air into the low-temperature pyrolysis reactor to be mixed with the waste gas; at least one layer of material with high adsorption performance is arranged in the reactor, harmful gas generated in the pyrolysis process is adsorbed and decomposed, gas in waste gas is subjected to a catalytic reaction through a catalyst, toxic substances in the waste gas are converted into harmless gas, and the gas in the waste gas is subjected to the catalytic reaction through the catalyst. Therefore, through the multi-level purification and energy recovery technology, the problems of low waste gas treatment efficiency, high energy consumption, incomplete pollutant removal and resource waste in the waste gas treatment process in the background technology are solved, more efficient waste gas treatment and energy self-sufficiency are realized, and the overall environmental protection performance of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of domestic waste exhaust gas treatment, and particularly to a method for treating domestic waste exhaust gas by low-temperature pyrolysis. Background Art

[0002] Currently, the commonly used incineration method for domestic waste treatment generates a large amount of exhaust gas, including harmful gases such as dioxins, nitrogen oxides, and volatile organic compounds (VOCs). Traditional exhaust gas treatment methods such as adsorption and catalytic conversion can partially reduce these harmful substances, but the treatment efficiency and equipment energy efficiency are still limited. In recent years, low-temperature pyrolysis technology has gradually received attention, which can reduce pollutant emissions and achieve resource recovery at relatively low temperatures;

[0003] Although existing exhaust gas treatment technologies can reduce harmful substances in emissions to a certain extent, there are still some deficiencies. For example, the exhaust gas treatment efficiency is not high, especially at low temperatures, and some harmful substances cannot be completely removed; the energy consumption during the treatment process is relatively large, and there is a lack of an effective energy recovery system. Moreover, existing methods mainly focus on the treatment of single pollutants and cannot efficiently treat multiple harmful gases and avoid secondary pollution. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent.

[0005] Therefore, the object of the present invention is to provide a method for treating domestic waste exhaust gas by low-temperature pyrolysis, which can achieve efficient purification of exhaust gas and recovery of useful resources by combining adsorption, catalysis, and gas recovery technologies, and solve the problems of low exhaust gas treatment efficiency, high energy consumption, and insufficient treatment of multiple pollutants in the existing technology.

[0006] To achieve the above object, the present invention provides a method for treating domestic waste exhaust gas by low-temperature pyrolysis, including the following steps:

[0007] S1. Input domestic waste into a low-temperature pyrolysis reactor and perform pyrolysis treatment within a temperature range of 300°C - 500°C;

[0008] S2. During the pyrolysis process, introduce air to mix with the exhaust gas to preliminarily dilute the harmful substances in the exhaust gas;

[0009] S3. Set at least one layer of material with high adsorption performance in the reactor to adsorb and decompose the harmful gases generated during the pyrolysis process;

[0010] S4. Perform a catalytic reaction on the gas in the exhaust gas through a catalyst to convert the toxic substances in the exhaust gas into harmless gases;

[0011] S5. Adopt a humidity and air flow control system to precisely adjust the exhaust gas flow rate and humidity to optimize the exhaust gas treatment effect;

[0012] S6. Discharge the treated waste gas into the atmosphere, meeting the national waste gas emission standards;

[0013] S7. Extract the combustible gas from the waste gas during pyrolysis, and collect and store it through a recovery system for combustion heating in the reactor or convert it into other utilizable energy sources.

[0014] In the method for treating waste gas from low-temperature pyrolysis of domestic waste according to the present invention, the domestic waste is heated in a low-temperature pyrolysis reactor in the range of 300°C - 500°C for treatment. The harmful substances in the waste gas are preliminarily diluted by introducing air and then enter a spraying device. An alkaline solution is used to remove soot, tar, and water-soluble pollutants. Then, the waste gas enters a filtration and purification device. After being treated by demisting, a composite adsorption material, and a catalytic layer, harmful gases are further removed. Through the action of the catalyst, nitrogen oxides and volatile organic compounds in the waste gas are converted into harmless gases. At the same time, the humidity and air flow control system optimizes the treatment effect to ensure that the waste gas emission meets national standards. The combustible gas in the treated waste gas is recovered and converted into heat energy or electrical energy for reactor heating, thereby improving energy efficiency and reducing external energy dependence. Through multi-level purification and energy recovery technologies, the problems of low waste gas treatment efficiency, high energy consumption, incomplete pollutant removal, and resource waste in the background technology are solved, achieving more efficient waste gas treatment and energy self-sufficiency, and improving the overall environmental protection performance of the system.

[0015] In addition, the method for treating waste gas from low-temperature pyrolysis of domestic waste proposed above according to the present invention may further have the following additional technical features:

[0016] Specifically, the recovery system includes a gas separation device, a gas storage unit, and a gas conversion unit, which are used to separate combustible gases such as methane and ethylene from the combustible gas extracted during pyrolysis and store them in the gas storage unit. The combustible gas can be used for combustion heating in the reactor or converted into other forms of energy, such as electrical energy or heat energy, through the gas conversion unit.

[0017] Specifically, the catalyst is a porous composite material composed of titanium-based, copper-based, molybdenum-based, and cerium-based metal oxides, which can effectively promote the conversion reaction of pollutants such as nitrogen oxides and volatile organic compounds in the waste gas at low temperatures and significantly reduce the concentration of harmful gases emitted.

[0018] Specifically, the adsorption material is a composite adsorbent composed of activated carbon, zeolite, and silica gel, which can simultaneously adsorb toxic gases and volatile organic compounds in the waste gas and effectively prevent them from being discharged into the atmosphere.

[0019] Specifically, the pyrolysis reactor is equipped with a multi-zone temperature control system that can adjust the temperature in different zones to ensure that the temperature gradient of the waste gas in the reactor meets the optimal treatment conditions, improving the waste gas treatment efficiency and the quality of pyrolysis products.

[0020] Specifically, the reactor is equipped with a real-time online monitoring system to monitor the pollutant concentration and treatment temperature in the waste gas, and combined with an automatic control system to adjust the temperature, humidity and gas flow rate of the pyrolysis process to optimize the waste gas treatment effect and ensure compliance with emissions.

[0021] Specifically, the energy recovery steps in the waste gas treatment process include a heat exchange system and a gas recovery system. The heat exchange system provides heating energy for the reactor by recovering the heat released during the reaction, while the gas recovery system recovers the combustible gas in the waste gas for reuse in the reactor, thereby improving the overall energy efficiency of the system and reducing external energy consumption.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, will become apparent in part from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of embodiments in conjunction with the drawings, wherein:

[0024] Figure 1 is a schematic diagram of the method for treating waste gas from low-temperature pyrolysis of domestic waste according to the present invention;

[0025] Figure 2 is a schematic diagram of the experimental data of Embodiment 1 of the present invention;

[0026] Figure 3 is a schematic diagram of the experimental data of Embodiment 2 of the present invention;

[0027] Figure 4 is a schematic diagram of the experimental data of Embodiment 3 of the present invention;

[0028] Figure 5 is a schematic diagram of the carbon dioxide capture rate data of the present invention Figure 1 ;

[0029] Figure 6 is a schematic diagram of the carbon dioxide capture rate data of the present invention Figure 2 。 DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention. On the contrary, the embodiments of the present invention include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0031] The method for treating waste gas from low-temperature pyrolysis of domestic waste according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0032] As Figures 1-4 shown, the method for treating waste gas from low-temperature pyrolysis of domestic waste according to an embodiment of the present invention may include the following steps:

[0033] S1. Input domestic waste into a low-temperature pyrolysis reactor and perform pyrolysis treatment within a temperature range of 300°C - 500°C.

[0034] It should be noted that in this embodiment, the domestic waste is input into the low-temperature pyrolysis reactor after pretreatment and pyrolyzed within a temperature range of 300°C - 500°C to ensure the gradual decomposition of organic matter and incombustibles in the waste under a controlled atmosphere, reduce the generation of harmful gases, and maximize the recovery of combustible gas and valuable solid residues to improve the pyrolysis efficiency and resource recovery rate.

[0035] S2. During the pyrolysis process, introduce air to mix with the waste gas to preliminarily dilute the harmful substances in the waste gas.

[0036] It should be noted that in this embodiment, during the pyrolysis process, by precisely controlling the air flow rate and introducing it into the reactor to mix with the waste gas, harmful gases such as nitrogen oxides and volatile organic compounds in the waste gas are effectively diluted, thereby reducing their concentration and creating favorable conditions for subsequent adsorption and catalytic treatment to improve the waste gas treatment efficiency.

[0037] S3. Set at least one layer of material with high adsorption performance in the reactor to adsorb and decompose the harmful gases generated during the pyrolysis process.

[0038] It should be noted that in this embodiment, at least one layer of material with high adsorption performance, such as activated carbon, zeolite, or silica gel composite adsorbent, is set in the reactor. These materials can effectively adsorb harmful gases in the waste gas, including volatile organic compounds (VOCs), nitrogen oxides (NOx), and heavy metals, etc. Through the molecular sieve effect of these adsorption materials, not only can the toxic substances in the waste gas be captured, but also some harmful gases can be decomposed through surface reactions, reducing emissions and improving the waste gas treatment efficiency.

[0039] S4. Catalyze the gases in the waste gas through a catalyst to convert the toxic substances in the waste gas into harmless gases.

[0040] It should be noted that in this embodiment, by setting specific catalysts in the reactor, such as titanium-based, copper-based or molybdenum-based metal oxides, these catalysts can promote the conversion reaction of toxic gases in the waste gas at low temperatures, converting harmful substances such as nitrogen oxides and volatile organic compounds (VOCs) into harmless gases such as nitrogen, water vapor and carbon dioxide. The catalytic reaction can not only significantly reduce the pollutant concentration in the waste gas, but also improve the reaction efficiency, reduce energy consumption, and ensure the environmental protection and economy of the waste gas treatment process.

[0041] S5. Adopt a humidity and air flow control system to precisely adjust the waste gas flow rate and humidity to optimize the waste gas treatment effect.

[0042] It should be noted that in this embodiment, the humidity and air flow control system described is used to precisely adjust the flow rate and humidity level of the waste gas by real-time monitoring the humidity and flow rate of the waste gas, so as to ensure that the contact time between the waste gas and the adsorption material and catalyst during the treatment process reaches the best. This system can dynamically adjust the air flow and humidity according to different waste gas components and treatment requirements, thereby optimizing the removal effect of harmful substances in the waste gas, improving the treatment efficiency, and reducing the energy consumption and equipment wear of the system.

[0043] S6. Discharge the treated waste gas into the atmosphere, meeting the national waste gas emission standards.

[0044] It should be noted that in this embodiment, the fully treated waste gas is discharged into the atmosphere through an exhaust system. Before discharge, the concentration of harmful substances in the waste gas is detected in real time through an on-line monitoring system to ensure that the concentration of each pollutant meets the national and regional waste gas emission standards, prevent secondary pollution, and further ensure the compliance and environmental safety of the discharged substances through an efficient filtration device.

[0045] S7. Extract the combustible gas from the waste gas during the pyrolysis process, and collect and store it through a recovery system for combustion heating in the reactor, or convert it into other utilizable energy.

[0046] It should be noted that in this embodiment, during the pyrolysis process, a gas separation device is set to extract combustible gases such as methane and ethylene from the waste gas, and these gases are separated, stored and regulated through a recovery system for combustion heating in the reactor, or converted into electric energy or heat energy through a gas conversion unit, further enhancing the energy self-sufficiency ability of the pyrolysis process and reducing the dependence on external energy.

[0047] Specifically, through low-temperature pyrolysis and a multi-stage waste gas treatment system, combined with materials with high adsorption performance, catalysts, and a gas recovery system, the waste gas generated during the low-temperature pyrolysis of domestic waste is effectively treated. First, the waste gas passes through a spray and filtration device to remove soot, tar, and harmful gases. Subsequently, the catalyst converts toxic substances into harmless gases, and the humidity and air flow control system is used to optimize the waste gas treatment effect. Finally, the waste gas meets the national emission standards, and the combustible gas in the waste gas is extracted and recovered for reactor heating or converted into other forms of energy, solving the problems of low treatment efficiency, high energy consumption, incomplete pollutant removal, and energy waste in traditional waste gas treatment methods. Through the dual optimization of waste gas purification and energy recovery, the treatment effect is improved and the operating cost is reduced.

[0048] In one embodiment of the present invention, as Figures 1-4 shown, the recovery system includes a gas separation device, a gas storage unit, and a gas conversion unit, which are used to separate combustible gases such as methane and ethylene from the combustible gas extracted during the pyrolysis process and store them in the gas storage unit. The combustible gas can be used for combustion heating in the reactor or converted into other forms of energy, such as electric energy or heat energy, through the gas conversion unit.

[0049] It should be noted that the recovery system described in this embodiment extracts and separates combustible gases such as methane and ethylene from the waste gas generated during the pyrolysis process through a gas separation device. These gases are stored in the gas storage unit after gas purification and compression. The stored combustible gas can be used for combustion heating in the reactor, improving the energy efficiency of the pyrolysis process. In addition, the gas conversion unit can convert the stored combustible gas into electric energy or heat energy to provide energy for other equipment, further improving the self-sufficiency of the system and the overall energy utilization efficiency.

[0050] In one embodiment of the present invention, as Figures 1-4 shown, the catalyst is a porous composite material composed of titanium-based, copper-based, molybdenum-based, and cerium-based metal oxides, which can effectively promote the conversion reaction of pollutants such as nitrogen oxides and volatile organic compounds in the waste gas at low temperatures and significantly reduce the concentration of harmful gases emitted.

[0051] It should be noted that the catalyst described in this embodiment uses a porous composite material composed of titanium-based, copper-based, molybdenum-based, and cerium-based metal oxides. Its unique multi-metal composition and high specific surface area can effectively promote the redox reaction of pollutants such as nitrogen oxides and volatile organic compounds (VOCs) in the waste gas at low temperatures, promoting their conversion into harmless nitrogen, water vapor, and carbon dioxide, thereby significantly reducing the concentration of harmful gases emitted, improving the reaction efficiency, reducing energy consumption, and prolonging the service life of the catalyst.

[0052] In one embodiment of the present invention, as Figures 1-4As shown, the adsorption material is a composite adsorbent composed of activated carbon, zeolite, and silica gel, which can simultaneously adsorb toxic gases and volatile organic compounds in waste gas and effectively prevent them from being discharged into the atmosphere.

[0053] It should be noted that the adsorption material described in this embodiment uses a composite adsorbent of activated carbon, zeolite, and silica gel. These materials can simultaneously adsorb toxic gases (such as sulfur dioxide and nitrogen oxides) and volatile organic compounds (VOCs) in waste gas through different adsorption mechanisms, and effectively prevent them from being discharged into the atmosphere through the porous structure, ensuring that the waste gas meets the environmental protection emission standards after being treated by the adsorbent and further reducing air pollution.

[0054] In an embodiment of the present invention, as Figures 1-4 shown, the pyrolysis reactor is equipped with a multi-zone temperature control system, which can adjust the temperature in different zones to ensure that the temperature gradient of the waste gas in the reactor meets the optimal treatment conditions, improving the waste gas treatment efficiency and the quality of pyrolysis products. The reactor is equipped with a real-time online monitoring system to monitor the pollutant concentration and treatment temperature in the waste gas, and combines an automatic control system to adjust the temperature, humidity, and gas flow rate during the pyrolysis process to optimize the waste gas treatment effect and ensure compliance with emissions. The energy recovery steps during the waste gas treatment process include a heat exchange system and a gas recovery system. The heat exchange system provides heating energy for the reactor by recovering the heat released during the reaction process, while the gas recovery system recovers combustible gases in the waste gas for reuse by the reactor, thereby improving the overall energy efficiency of the system and reducing external energy consumption.

[0055] It should be noted that the pyrolysis reactor described in this embodiment uses a multi-zone temperature control system. By precisely adjusting the temperature of each zone, it ensures that the temperature gradient of the waste gas in the reactor remains within the optimal range to achieve efficient pyrolysis reactions and high-quality pyrolysis products. The equipped real-time online monitoring system can continuously monitor the pollutant concentration and treatment temperature in the waste gas, and combine with the automatic control system to dynamically adjust the temperature, humidity, and gas flow rate to optimize the waste gas treatment effect and ensure that the emissions meet environmental protection standards. In addition, the energy recovery system during the waste gas treatment process includes a heat exchange system and a gas recovery system. The heat exchange system provides the necessary heating energy for the reactor by recovering the heat released during the reaction process, while the gas recovery system recovers combustible gases from the waste gas for reuse by the reactor, further improving the overall energy utilization efficiency and reducing the dependence on external energy.

[0056] Example 1

[0057] Step 1: Input domestic waste into the low-temperature pyrolysis reactor, and control the temperature in the reactor within the range of 300°C - 500°C for pyrolysis treatment. The pyrolysis reactor adopts a partition temperature control design, and the temperature of each zone is optimized according to the waste gas flow rate and treatment requirements to ensure the efficiency and low energy consumption of the reaction process.

[0058] Step 2: During the pyrolysis process, by introducing a preset amount of air to mix with the waste gas, the harmful substances in the waste gas such as nitrogen oxides and volatile organic compounds are preliminarily diluted. The mixing ratio of air to waste gas is controlled between 1:3 and 1:5 to ensure that the waste gas dilution effect reaches 30% - 50%.

[0059] Step 3: Set at least one layer of material with high adsorption performance in the reactor, such as a composite adsorbent composed of activated carbon and zeolite, which can simultaneously adsorb toxic gases and volatile organic compounds in the waste gas. During the treatment process, this material can adsorb approximately 40% - 60% of the harmful substances in the waste gas.

[0060] Step 4: By setting up a catalytic reaction unit and using a titanium-based composite material as a catalyst, promote the conversion reaction of nitrogen oxides and volatile organic compounds in the waste gas at low temperature, and convert them into harmless gases such as nitrogen and water vapor. The working temperature of this catalyst is 350°C - 450°C, which can significantly reduce the concentration of harmful gases by 40% - 60%.

[0061] Step 5: Adopt a humidity and air flow control system to monitor the waste gas flow and humidity in real time and accurately adjust according to the actual situation. The humidity range is controlled between 40% - 60% to optimize the waste gas treatment effect and ensure that the discharged gas is within the compliance range.

[0062] Step 6: Discharge the treated waste gas into the atmosphere, monitor the waste gas composition through a real-time online monitoring system, and ensure that all emission standards meet the national environmental protection requirements. The discharged gas is further purified through a high-efficiency filter and finally meets the standards for discharge.

[0063] Step 7: During the pyrolysis process, extract the combustible gas from the waste gas, and separate combustible gases such as methane and ethylene through a gas separation device. The extracted gas is stored in a gas storage unit and can be used for combustion heating in the reactor, or converted into other available energy sources such as electricity or heat through a gas conversion unit.

[0064] Experimental data comparison (as Figure 2 shown):

[0065] Experimental data analysis:

[0066] Gas yield: As the temperature increases, the gas yield gradually increases, reaching a maximum of 67% (500°C), indicating that a higher temperature is conducive to the conversion of more organic matter into gas.

[0067] Removal rate of harmful substances: At different temperatures, the removal rate of harmful substances in the waste gas gradually increases, from 55% at 300°C to 80% at 500°C, reflecting the improvement of the waste gas purification effect by temperature.

[0068] Solid residue: The solid residue gradually decreases with the increase in temperature, from 55% at 300 °C to 33% at 500 °C, indicating that high temperature helps to reduce solid waste.

[0069] Carbon dioxide emissions: With the increase in temperature, the carbon dioxide emissions gradually decrease, and the emissions at 500 °C are 85 g / kg, indicating that the organic matter in the waste gas is completely decomposed under high temperature conditions, and the carbon dioxide emissions are cleaner.

[0070] Example 2

[0071] On the basis of Example 1, in Step 1, the spraying device is used to treat the soot and tar substances in the waste gas. The spraying liquid uses a sodium hydroxide solution with a concentration of 1%. The removal rate of soot and tar substances in the waste gas after spraying is 80% - 90%. In Step 2, the mixing ratio of air to waste gas is controlled at 1:4 to further improve the dilution effect of the waste gas. The catalyst used in Step 4 is copper-based metal oxide, which improves the removal rate of nitrogen oxides and reduces the emission concentration of harmful substances in the waste gas to 50% - 70%.

[0072] Experimental data comparison (as Figure 3 shown)

[0073] Experimental data analysis:

[0074] Gas yield: With the optimization of the spraying liquid and the use of the catalyst, the gas yield has increased, and the gas yield reaches 70% at 500 °C.

[0075] Removal rate of harmful substances: Under the dual action of spraying and the catalyst, the removal rate of harmful substances has increased significantly and reaches 82% at 500 °C.

[0076] Solid residue: The solid residue decreases from 54% at 300 °C to 30% at 500 °C, more effectively reducing solid waste.

[0077] Carbon dioxide emissions: The carbon dioxide emissions decrease from 125 g / kg at 300 °C to 80 g / kg at 500 °C, indicating that the use of spraying and the catalyst further reduces carbon emissions.

[0078] Example 3

[0079] Based on Example 1, the spray liquid in Step 1 is a sodium hydroxide solution with a concentration of 5%, which can remove 75% - 85% of the soot and tar substances in the waste gas. The catalyst in Step 4 is a molybdenum-based metal oxide, and its catalytic effect at high temperatures is more significant, which can convert volatile organic compounds and nitrogen oxides in the waste gas into harmless gases, with a conversion rate reaching 60% - 80%. The gas recovery system in Step 7 can recover more combustible gases and store them for subsequent use, improving the energy efficiency of the system.

[0080] Experimental data comparison (as Figure 4 shown)

[0081] Analysis of experimental data:

[0082] Gas yield: With the optimization of the catalyst and the increase in the concentration of the spray liquid, the gas yield is further improved, reaching 73% at 500°C.

[0083] Removal rate of harmful substances: The removal rate of harmful substances in the waste gas has also increased significantly, reaching 85% at 500°C.

[0084] Solid residue: The solid residue decreases significantly with the increase in temperature, and the solid residue at 500°C is 30%.

[0085] Carbon dioxide emissions: Through the optimization of the treatment process, the carbon dioxide emissions are further reduced, being 75 g / kg at 500°C, indicating that while maintaining the energy efficiency, the system reduces carbon emissions.

[0086] In summary, for the low-temperature pyrolysis domestic waste gas treatment method of the embodiments of the present invention, domestic waste is heated to the range of 300°C - 500°C in a low-temperature pyrolysis reactor for treatment. The harmful substances in the waste gas are preliminarily diluted by introducing air and then enter the spray device, where an alkali solution is used to remove soot, tar, and water-soluble pollutants. Then, the waste gas enters the filter purification device, and after being treated by demisting, a composite adsorption material, and a catalytic layer, harmful gases are further removed. Through the action of the catalyst, nitrogen oxides and volatile organic compounds in the waste gas are converted into harmless gases. At the same time, the humidity and air flow control system optimizes the treatment effect to ensure that the waste gas emissions meet national standards. The combustible gases in the treated waste gas are recovered and converted into heat energy or electrical energy for reactor heating, thereby improving energy efficiency and reducing external energy dependence. Through multi-level purification and energy recovery technologies, the problems of low waste gas treatment efficiency, high energy consumption, incomplete pollutant removal, and resource waste in the waste gas treatment process in the background technology are solved, achieving more efficient waste gas treatment and energy self-sufficiency, and improving the overall environmental protection performance of the system.

[0087] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for treating waste gas from low-temperature pyrolysis of domestic waste, characterized in that: The following steps are involved: S1. The domestic garbage is input into a low-temperature pyrolysis reactor and pyrolyzed at a temperature in the range of 300°C-500°C; S2. During the pyrolysis process, air is introduced to mix with the exhaust gas to initially dilute the harmful substances in the exhaust gas; S3. Arrange at least one layer of material with high adsorption performance in the reactor to adsorb and decompose harmful gases generated during the pyrolysis process; S4, catalyzing the gas in the exhaust gas through the catalyst to convert the toxic substances in the exhaust gas into harmless gas; S5. Use humidity and airflow control system to accurately adjust the exhaust gas flow and humidity to optimize the exhaust gas treatment effect; S6. Discharge the treated waste gas into the atmosphere in compliance with national waste gas emission standards; S7. During the pyrolysis process, combustible gases in the exhaust gas are extracted and collected and stored through a recovery system for use in combustion heating in the reactor or converted into other usable energy.

2. The method for treating waste gas from low-temperature pyrolysis of domestic waste according to claim 1, characterized in that: The recovery system includes a gas separation device, a gas storage unit and a gas conversion unit, which are used to separate combustible gases such as methane and ethylene from the combustible gases extracted during the pyrolysis process and store them in the gas storage unit. The combustible gases can be used for combustion and heating in the reactor, or converted into other forms of energy, such as electrical energy or thermal energy, through the gas conversion unit.

3. The method for treating waste gas from low-temperature pyrolysis of domestic waste according to claim 1, characterized in that: The catalyst is a porous composite material composed of titanium-based, copper-based, molybdenum-based and cerium-based metal oxides. It can effectively promote the conversion reaction of pollutants such as nitrogen oxides and volatile organic compounds in exhaust gas at low temperatures and significantly reduce the concentration of harmful gases emitted.

4. The method for treating waste gas from low-temperature pyrolysis of domestic waste according to claim 1, characterized in that: The adsorption material is a composite adsorbent composed of activated carbon, zeolite and silica gel, which can simultaneously adsorb toxic gases and volatile organic compounds in the exhaust gas and effectively prevent them from entering the atmosphere.

5. The method for treating waste gas from low-temperature pyrolysis of domestic waste according to claim 1, characterized in that: The pyrolysis reactor is equipped with a multi-zone temperature control system that can adjust the temperature in different zones to ensure that the temperature gradient of the exhaust gas in the reactor meets the optimal treatment conditions, thereby improving the exhaust gas treatment efficiency and the quality of the pyrolysis products.

6. The method for treating waste gas from low-temperature pyrolysis of domestic waste according to claim 1, characterized in that: The reactor is equipped with a real-time online monitoring system to monitor the pollutant concentration and treatment temperature in the exhaust gas, and combines with the automatic control system to adjust the temperature, humidity and airflow rate of the pyrolysis process to optimize the exhaust gas treatment effect and ensure emission compliance.

7. The method for treating waste gas from low-temperature pyrolysis of domestic waste according to claim 1, characterized in that: The energy recovery steps in the waste gas treatment process include a heat exchange system and a gas recovery system. The heat exchange system provides heating energy for the reactor by recovering the heat released during the reaction, while the gas recovery system recovers the combustible gas in the waste gas for reuse in the reactor, thereby improving the overall energy efficiency of the system and reducing external energy consumption.

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