Sectional type anoxic cracking method for household garbage

Abstract

The invention discloses a household garbage sectional type anoxic cracking method which comprises the following steps that at least three independent cracking areas are arranged in a cracking furnace, the temperature, atmosphere and oxygen concentration of each cracking area can be intelligently adjusted according to real-time monitoring data, the temperature of the first cracking area is 200-400 DEG C, the atmosphere is in an anoxic state, and the oxygen concentration of the second cracking area is in an anoxic state; organic matters and volatile matters are preferentially cracked to generate low-calorific-value gas and liquid products, the temperature of the second cracking zone is 400-600 DEG C, residual organic matters are further cracked in an anoxic atmosphere to reduce generation of harmful gases and convert the residual organic matters into solid carbide and part of combustible gases, and the temperature of the third cracking zone is 600-800 DEG C to generate low-calorific-value gas and liquid products. Plastic, rubber and other synthetic materials are cracked in an inert atmosphere, gas and solid products are recovered, and efficient energy recovery is ensured. Therefore, the problems of low cracking efficiency, high pollution emission, insufficient energy efficiency and resource waste in the prior art are solved, and efficient, environment-friendly and resource garbage treatment is realized.

Description

Technical Field

[0001] The invention relates to the technical field of domestic waste treatment, and in particular to a staged anoxic pyrolysis method for domestic waste. Background Art

[0002] At present, domestic waste is mainly treated through incineration, landfill and composting. However, incineration will release a large amount of harmful gases, such as sulfur dioxide and nitrogen oxides, which will pollute the environment; landfill and composting are inefficient and require a lot of land resources. In order to treat waste more efficiently and environmentally friendly, it is urgent to develop new technologies;

[0003] The existing garbage pyrolysis methods have the problem of inaccurate temperature and atmosphere control, and are unable to optimize the pyrolysis process according to different garbage components, resulting in poor pyrolysis effects, insufficient energy recovery, and high harmful emissions. In addition, the waste gas purification efficiency is low, and energy recovery and utilization are not fully optimized. Therefore, there is an urgent need for a new, intelligent garbage pyrolysis technology to improve processing efficiency and environmental protection. Summary of the invention

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

[0005] To this end, the purpose of the present invention is to propose a segmented anoxic pyrolysis method for domestic waste, optimize the pyrolysis process through an intelligent atmosphere control system, improve the pyrolysis efficiency of different waste components, and recover waste heat through a multi-stage recovery system to improve energy utilization efficiency, thereby solving the problems of poor pyrolysis effect, insufficient energy recovery and excessive harmful gas emissions in the prior art, and providing an efficient and environmentally friendly waste treatment solution.

[0006] To achieve the above object, the present invention proposes a staged anoxic pyrolysis method for domestic waste, comprising the following steps:

[0007] S1. Put the domestic waste into the cracking furnace in sections. The cracking furnace is equipped with at least three independent cracking zones. The temperature, atmosphere and oxygen concentration of each cracking zone can be intelligently adjusted according to real-time monitoring data;

[0008] S2, the temperature of the first cracking zone is 200℃ to 400℃, the atmosphere is in an oxygen-deficient state, organic matter and volatile matter are preferentially cracked to produce low calorific value gas and liquid products, the temperature of the second cracking zone is 400℃ to 600℃, the remaining organic matter is further cracked in an oxygen-deficient atmosphere, the generation of harmful gases is reduced, and it is converted into solid carbonized products and part of the combustible gas, the temperature of the third cracking zone is 600℃ to 800℃, plastics, rubber and other synthetic materials are cracked in an inert atmosphere, gas and solid products are recovered, and efficient energy recovery is ensured;

[0009] S3. During the cracking process, the intelligent atmosphere control system automatically adjusts the atmosphere and temperature of each cracking zone according to real-time data monitoring to optimize the cracking efficiency and reduce harmful emissions;

[0010] S4. The combustible gas and liquid products produced during the cracking process are collected and refined separately to generate high-quality fuel gas and oil products, with a recovery rate of more than 90%;

[0011] S5. The waste heat generated by the cracking furnace is recovered through a multi-stage heat exchange system with a recovery efficiency of not less than 90%, and is used to supplement heating of the cracking furnace and drive the power generation device;

[0012] S6. Remove particulate matter, nitrogen oxides and sulfur dioxide from the exhaust gas through the exhaust gas purification system, ensuring that the particulate matter removal rate is not less than 95%, and the nitrogen oxide and sulfur dioxide emissions are less than 50ppm and 30ppm respectively.

[0013] The domestic waste segmented anoxic cracking method of the present invention divides the domestic waste into multiple cracking zones through segmented anoxic cracking technology. Each cracking zone optimizes the cracking process according to the temperature and atmosphere to ensure that different waste components are efficiently cracked under the most suitable conditions. The intelligent atmosphere control system monitors and adjusts the temperature, oxygen concentration and gas composition in the cracking zone in real time to ensure the cracking efficiency and environmental performance. The waste gas purification system adopts catalytic reduction and adsorption devices to remove nitrogen oxides, sulfur dioxide and particulate matter to ensure that emissions meet environmental standards. At the same time, the waste heat recovery system recovers the waste heat in the cracking process through multi-stage heat exchange, and the recovery rate reaches more than 90%, which is used to heat the cracking furnace or generate electricity to improve the system energy efficiency. In addition, the metal recovery device recovers the metals generated in the cracking process through physical separation technology, improves the resource recovery rate and realizes reuse, effectively solving the problems of low cracking efficiency, high pollution emissions, insufficient energy efficiency and resource waste in the background technology, and realizes efficient, environmentally friendly and resource-based waste treatment.

[0014] In addition, the above-mentioned staged anoxic pyrolysis method for domestic waste according to the present invention may also have the following additional technical features:

[0015] Specifically, the intelligent atmosphere control system adjusts the concentration of oxygen, nitrogen, carbon dioxide and other gases in the atmosphere through real-time data monitoring.

[0016] Specifically, an airflow isolation device is provided between the second cracking zone and the first cracking zone to ensure the stability of the atmosphere and temperature and to prevent cross-effects of heat or gas.

[0017] Specifically, the atmosphere in the cracking furnace can achieve cracking reactions in different temperature ranges by fine-tuning the oxygen concentration, so that the garbage components can be cracked in the most suitable environment.

[0018] Specifically, the gas collection system includes multi-stage filters and condensers, which can recover harmful substances in the gas and extract high-quality fuel gas.

[0019] Specifically, the exhaust gas purification system includes catalytic reduction and adsorption devices to effectively remove harmful substances during the cracking process.

[0020] Specifically, the waste heat generated during the cracking process can be recovered through a heat exchange system and used for further heating or power generation, thereby improving the energy efficiency of the system.

[0021] Specifically, the metal recovery unit recovers the metals generated during the cracking process by physical separation, ensuring a high recovery rate of the metals and returning them to the production chain for reuse.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through 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 easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0024] Figure 1 It is a schematic diagram of the staged anoxic pyrolysis method of domestic waste of the present invention;

[0025] Figure 2 It is a schematic diagram comparing the cleavage efficiency and products of the present invention;

[0026] Figure 3 Schematic diagram of the effect of intelligent regulation on lysis efficiency of the present invention;

[0027] Figure 4 A schematic diagram of the environmental protection and energy recovery performance of the present invention;

[0028] Figure 5 Schematic diagram of the intelligent control system of the present invention. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations of the present invention. On the contrary, embodiments of the present invention include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0030] The following describes the staged anoxic pyrolysis method for domestic waste according to an embodiment of the present invention in conjunction with the accompanying drawings.

[0031] like Figure 1-Figure 5 As shown, the staged anoxic pyrolysis method for domestic waste according to the embodiment of the present invention may include the following steps:

[0032] S1. Put the domestic waste into the cracking furnace in sections. There are at least three independent cracking zones in the cracking furnace. The temperature, atmosphere and oxygen concentration of each cracking zone can be intelligently adjusted according to real-time monitoring data.

[0033] It should be noted that the domestic waste is fed into the cracking furnace in sections as described in this embodiment. A plurality of independent cracking zones are provided in the cracking furnace. The temperature, atmosphere and oxygen concentration of each cracking zone can be monitored in real time by built-in sensors, and intelligently adjusted according to data feedback to ensure that the working conditions of each cracking zone are optimized, thereby improving the cracking efficiency of different types of waste. The intelligent control system can accurately control the temperature and atmosphere changes during the cracking process, accurately process the pyrolysis characteristics of different waste components, reduce the generation of harmful substances and improve energy recovery efficiency.

[0034] S2. The temperature of the first cracking zone is 200℃ to 400℃, and the atmosphere is in an oxygen-deficient state. Organic matter and volatile substances are preferentially cracked to produce low calorific value gas and liquid products. The temperature of the second cracking zone is 400℃ to 600℃. The remaining organic matter is further cracked in an oxygen-deficient atmosphere to reduce the generation of harmful gases and convert them into solid carbonized products and part of the combustible gas. The temperature of the third cracking zone is 600℃ to 800℃. Plastics, rubber and other synthetic materials are cracked in an inert atmosphere, and gas and solid products are recovered to ensure efficient energy recovery.

[0035] It should be noted that the first cracking zone described in this embodiment promotes the initial cracking of organic matter and volatiles through an oxygen-deficient atmosphere within a temperature range of 200°C to 400°C, produces low calorific value gas and liquid products, reduces the generation of harmful gases during pyrolysis, and provides basic energy for subsequent cracking; the temperature of the second cracking zone is set at 400°C to 600°C, and the remaining organic matter is further cracked through a continuous oxygen-deficient atmosphere to reduce the generation of volatile organic matter, and by controlling the temperature and atmosphere, the organic matter is converted into solid carbonized products and part of the combustible gas, further optimizing the combination of cracking products; the temperature of the third cracking zone is 600°C to 800°C, and an inert atmosphere (such as nitrogen or carbon dioxide) is used to crack plastics, rubber and other synthetic materials, reduce the generation of harmful gases and ensure the maximum recovery efficiency of the products during the cracking process. The recovered gas and solid products can be used for energy supplementation to ensure efficient energy recovery and sustainability of the cracking process.

[0036] It should be understood that the specific catalyst introduced is usually a transition metal oxide catalyst, such as metal oxides such as molybdenum (Mo), cobalt (Co), and nickel (Ni). These metal oxides have strong catalytic activity and can promote the selective reaction of carbon dioxide with other gas components, thereby improving the capture efficiency of carbon dioxide. In addition, these catalysts have good stability in high temperature environments and are suitable for use in the gasification process. They can effectively separate carbon dioxide from other gas components and guide it to the carbon dioxide absorption system.

[0037] S3. During the cracking process, the intelligent atmosphere control system automatically adjusts the atmosphere and temperature of each cracking zone based on real-time data monitoring to optimize cracking efficiency and reduce harmful emissions.

[0038] It should be noted that in the cracking process described in this embodiment, the intelligent atmosphere control system collects key data of each cracking zone in real time through integrated temperature sensors, gas concentration monitors and oxygen concentration sensors. The system automatically adjusts the temperature and atmosphere composition (such as oxygen, nitrogen, carbon dioxide, etc.) of each zone through high-speed data processing and analysis to optimize the cracking reaction rate and improve energy recovery efficiency; the system also combines feedback control and self-learning algorithms, and can flexibly adjust operating parameters according to the characteristics of different garbage components to ensure that the atmosphere and temperature during the cracking process are always in the optimal range, thereby effectively reducing the emission of harmful gases and improving the overall environmental protection and efficiency of the system.

[0039] Intelligent control process:

[0040] Real-time data monitoring: Multiple sensors are installed in each cracking zone of the cracking furnace, including temperature sensors, oxygen concentration sensors, gas composition analyzers, etc. These sensors monitor the temperature, atmosphere composition (such as oxygen concentration, nitrogen concentration, etc.) of each cracking zone and the main components of the cracking gas (such as CO2, CH4, etc.) in real time. These data are transmitted to the intelligent control system through the data acquisition system.

[0041] Data transmission and processing: Real-time data is transmitted wirelessly or wired to the central processing unit (CPU) of the intelligent control system. The unit will analyze and process the data according to the preset cracking conditions and optimization algorithms. The intelligent control system compares the real-time data of each cracking zone with the target parameters (such as cracking efficiency, pollutant emission standards, etc.) and calculates the optimal temperature, atmosphere and oxygen concentration required for each cracking zone.

[0042] It should be noted that:

[0043] 1. Data transmission and processing, including:

[0044] Data collection:

[0045] In each cracking zone, sensors monitor parameters such as temperature, atmosphere composition (such as oxygen, nitrogen, carbon dioxide concentration, etc.), pressure, and gas flow in real time.

[0046] This data is transmitted to the central processing unit (CPU) of the intelligent control system via wireless or wired transmission, for example, via Wi-Fi or industrial Ethernet.

[0047] Data preprocessing:

[0048] Denoising: Data transmission may be interfered with, so filtering algorithms (such as Kalman filtering or mean filtering) are needed to remove noise to ensure data accuracy.

[0049] Data standardization: The output data of different sensors may have different dimensions, so the data needs to be standardized. For example, temperature data, gas concentration, etc. must be converted into the same standard units for unified processing.

[0050] 2. Real-time data analysis and comparison:

[0051] The real-time data is compared with the preset cracking conditions (such as optimal temperature range, target atmosphere, etc.), and the optimal cracking conditions are determined based on these target parameters.

[0052] Process for calculating optimal temperature, atmosphere and oxygen concentration

[0053] Chemical reaction and temperature model:

[0054] According to the reaction characteristics of different cracking zones, a temperature dependence model of the cracking reaction is established. For example, in the low-temperature cracking zone, when the temperature is low, the cracking rate of organic matter is slow and a certain temperature needs to be maintained; in the high-temperature cracking zone, the oxygen concentration needs to be used to control the cracking rate and energy consumption.

[0055] The Arrhenius equation is often used to describe the relationship between temperature and chemical reaction rate:

[0056]

[0057] Where k is the reaction rate constant, A is the frequency factor, and E a is the activation energy, R is the gas constant, and T is the temperature.

[0058] It should be noted that this equation calculates k through the known temperature T and adjusts the process parameters according to experimental data. a (J / mol) represents the minimum energy required for the reaction, which can be obtained through experimental determination or literature search, such as E for methane cracking. a =355 kJ / mol, E of cellulose lysis a=160-200 kJ / mol; the gas constant R is fixed at 8.314 J / (mol·K), which is a universal physical constant.

[0059] Using this equation, the reaction rate constant k is calculated by the Arrhenius equation, and the optimal temperature that needs to be maintained to maximize the cracking efficiency can be calculated based on the reaction rates at different temperatures.

[0060] Activation energy such as:

[0061] Methane cracking: E a =355kJ / mol

[0062] Cellulose lysis: E a =160-200 kJ / mol

[0063] Plastic cracking: E a =120-180kJ / mol

[0064] Gas constant R

[0065] R = 8.314 J / (mol·K) (international gas constant)

[0066] The reaction rates at different temperatures are obtained through experimental measurements. For example, at 800°C, 900°C, and 1000°C, the amount of cracking products (such as combustible gases) generated per unit time is measured, and the corresponding reaction rate constant kkk is calculated. The experimental results show that the cracking rate is low at 800°C, significantly increases at 900°C, and reaches the best balance at 1000°C. However, after further increasing the temperature to 1100°C, the by-products increase and the energy consumption is too high. Therefore, combining the cracking efficiency and energy consumption, 1000°C is selected as the optimal cracking temperature to ensure that the reaction is efficient and economically feasible.

[0067] Atmosphere and oxygen concentration calculation:

[0068] Oxygen concentration affects the rate of oxidation reaction during the cracking process. Too high oxygen concentration will lead to excessive oxidation, while too low oxygen concentration will result in incomplete cracking.

[0069] According to the relationship between oxygen concentration and temperature, the required oxygen supply can be calculated by the oxygen concentration model. Commonly used mathematical models include gas flow models based on the principle of mass conservation:

[0070]

[0071] Among them, Q 氧气 is the oxygen flow rate, V 裂解区 is the volume of the cracking zone, the target oxygen concentration and the current oxygen concentration are the oxygen concentrations in the cracking zone.

[0072] Assume that the volume of a cracking zone is 15m 3 , the target oxygen concentration is set at 4.0%, the current oxygen concentration is 5.5%, and the oxygen supply needs to be reduced to optimize the cracking reaction and prevent over-oxidation. The current system supplies 3.0m per minute 3 To reduce the oxygen concentration to the target value, the gas flow model is used to calculate the required oxygen adjustment:

[0073] Calculate the amount of oxygen that needs to be reduced:

[0074]

[0075] Substitute the data:

[0076]

[0077] Adjustment strategy:

[0078] During initial adjustment, reduce oxygen supply by 0.045m 3 / min, so that the oxygen concentration gradually decreases;

[0079] After 5 minutes, the oxygen concentration was monitored to be down to 4.2%, and the oxygen supply was further reduced by 0.015 m 3 / min for fine adjustment;

[0080] After 10 minutes, the oxygen concentration stabilizes at the target value of 4.0%, and the system stops adjusting and maintains the current supply.

[0081] By calculating and gradually adjusting the oxygen supply, the system successfully reduced the oxygen concentration from 5.5% to 4.0%, preventing over-oxidation and ensuring that the cracking process operates within the optimal oxygen concentration range, improving cracking efficiency while reducing by-product and pollutant emissions.

[0082] Optimization algorithm and objective function:

[0083] In order to determine the best operating conditions (temperature, atmosphere, oxygen concentration, etc.), multi-objective optimization algorithms such as genetic algorithm (GA), particle swarm optimization (PSO) or simulated annealing algorithm can be used for parameter optimization.

[0084] The objective function includes minimization of cracking efficiency and pollutant emissions. For example, the objective function can be expressed as:

[0085] F (temperature, atmosphere, oxygen concentration) = w1·cracking efficiency-w2·pollutant emissions

[0086] Among them, w1 and w2 are weight coefficients used to balance the trade-off between cracking efficiency and pollutant emissions.

[0087] The weight coefficients w1 and w2 control the optimization direction. When w1>w2, the optimization goal tends to improve the cracking efficiency. For example, 900℃ is selected to achieve a cracking efficiency of 85%, even if NOx and SO2 emissions increase slightly. When w2>w1, it tends to reduce pollutant emissions. For example, at 800℃, NOx and SO2 emissions are the lowest, but the cracking efficiency is only 70%. By setting different weight combinations, the objective function can guide the intelligent control system to dynamically adjust the cracking temperature and oxygen concentration to ensure that the energy recovery rate is optimized while meeting environmental protection standards, achieving a comprehensive balance between economy and environmental protection.

[0088] Real-time optimization and adjustment:

[0089] Feedback control: Based on the comparison between real-time data and the objective function, the control system adjusts the temperature, oxygen concentration and atmosphere of the cracking zone, and makes adjustments through control equipment (such as heaters, cooling systems, gas regulating valves) to ensure that each cracking zone is in the optimal operating state.

[0090] It should be noted that the purpose of feedback control comparison is to determine whether the temperature and oxygen concentration of the current cracking zone deviate from the optimal range and determine whether adjustments are needed. After calculation, if F(T) is lower than the set threshold, it means that the cracking efficiency is reduced or the pollutant emission exceeds the standard, and the temperature or oxygen concentration needs to be adjusted; for example, when the temperature is lower than the optimal range (such as 900°C to 850°C), the cracking efficiency decreases, and the system will increase the heating amount to restore the target value; on the contrary, if the temperature is too high (such as exceeding 1000°C), it may cause excessive cracking or increase in by-products, and the system will start the cooling system to lower the temperature; when the calculated F(T) is in the optimal range and the temperature and oxygen concentration fluctuations are within the allowable range, it means that the system is operating normally and does not need to be adjusted, thereby maintaining the stability and efficiency of the cracking process.

[0091] PID control (proportional-integral-derivative control) is used to adjust the temperature and oxygen concentration in real time to ensure the stability and efficiency of the cracking reaction.

[0092] It should be noted that in the PID control of the cracking process, the system monitors the temperature and oxygen concentration in real time, and compares them with the preset target values, and automatically adjusts the heating, cooling or gas supply according to the deviation. For example, if the target temperature is set to 900°C, but the current temperature drops to 870°C, the system will immediately increase the heating power and reduce the cooling gas supply to raise the temperature; if the temperature rises to 940°C, the system will reduce the heating power and increase the cooling gas flow to quickly reduce the temperature back to the target value. Similarly, if the target oxygen concentration is set to 4%, but 5% is monitored in real time, the system will automatically reduce the oxygen supply, reduce the cracking reaction rate, and prevent excessive oxidation, thereby improving energy utilization and reducing pollutant emissions.

[0093] Algorithms combined with chemical models:

[0094] Application of the combination of algorithms and chemical models: By combining chemical reaction kinetic models (such as the Arrhenius equation) with optimization algorithms (such as genetic algorithms), dynamic adjustment of various parameters in the cracking process can be achieved.

[0095] Real-time feedback and self-learning: The system conducts self-learning through historical data and real-time monitoring data, and continuously adjusts the parameters of the optimization algorithm to achieve more precise control and optimization.

[0096] Therefore, by combining the chemical reaction model with the optimization algorithm, the temperature, atmosphere and oxygen concentration of each cracking zone can be dynamically calculated and adjusted to ensure the best reaction efficiency and the lowest pollutant emissions during the cracking process. The comparison of real-time data with target parameters, the application of the optimization algorithm and the adjustment of the feedback control system ensure the intelligence, efficiency and environmental protection of the cracking process.

[0097] Control and intelligent adjustment: After the analysis and processing is completed, the control system issues adjustment instructions based on the calculation results to adjust the temperature and oxygen concentration in the cracking zone. The system intelligently adjusts in the following ways:

[0098] Temperature regulation: when the temperature in the cracking zone is lower than the target value, the intelligent control system will adjust the heating equipment (such as electric heater, hot air flow regulation system) to increase heat to ensure that the cracking temperature reaches the predetermined range. If the temperature is too high, the cooling system (such as cooling air flow or cooling liquid injection) will be adjusted to lower the temperature.

[0099] Atmosphere regulation: Based on real-time monitoring data, the control system adjusts the gas supply system (such as oxygen, nitrogen and carbon dioxide) to maintain the ideal atmosphere in the cracking zone. For example, in the low-temperature cracking zone, the system may increase the nitrogen concentration and reduce the oxygen concentration to promote the slow cracking of organic matter; in the high-temperature cracking zone, the system will reduce the oxygen concentration to prevent excessive oxidation.

[0100] Oxygen concentration adjustment: The oxygen concentration is controlled by adjusting the oxygen supply to ensure that the oxygen concentration in each cracking zone meets the target cracking conditions. This adjustment is based on a preset oxygen demand model to avoid excessively high or low oxygen concentrations that affect cracking efficiency and product quality.

[0101] Optimization and adaptive adjustment: The system continuously optimizes the control strategy according to the dynamic changes in the cracking process (such as changes in different garbage components). Whenever changes are detected in the key parameters of the cracking process, the control system will automatically adjust the working conditions of the cracking zone to ensure that the cracking reaction continues to be efficient and uniform, and reduce pollutant generation.

[0102] Specific applications:

[0103] In the first cracking zone, the temperature is relatively low (200℃-400℃), the atmosphere is oxygen-deficient, and the system automatically adjusts the oxygen concentration to control the cracking reaction rate, giving priority to cracking organic matter.

[0104] In the second cracking zone (400°C-600°C), the system adjusts the oxygen concentration to increase the reaction rate and reduce the generation of harmful gases while maintaining an oxygen-deficient atmosphere.

[0105] In the third cracking zone (600℃-800℃), the system will reduce the oxygen concentration to ensure the plastic and rubber cracking process at high temperature.

[0106] Through this intelligent control process, each cracking zone in the cracking furnace can dynamically adjust the temperature, atmosphere and oxygen concentration according to real-time monitoring data to ensure efficient cracking reactions, improve resource recovery, reduce energy waste, and control pollutant emissions. This intelligent control method solves the problem of difficult precise control of temperature and atmosphere in traditional cracking technology, and greatly improves cracking efficiency and environmental performance.

[0107] S4. The combustible gas and liquid products produced during the cracking process are collected and refined separately to generate high-quality fuel gas and oil products, with a recovery rate of more than 90%.

[0108] It should be noted that the combustible gas and liquid products generated in the cracking process described in this embodiment are diverted and refined through a multi-stage collection system, the gas is extracted through a condensation and distillation device to obtain high calorific value fuel gas, and the liquid product is dehydrated and refined to remove impurities and harmful components and converted into high-quality oil products, ensuring a recovery rate of more than 90%; this process not only improves the energy utilization efficiency, but also maximizes the recovery of cracking products by optimizing the distribution and refining of gas and liquid products, reduces resource waste and improves economic benefits.

[0109] S5. The waste heat generated by the cracking furnace is recovered through a multi-stage heat exchange system with a recovery efficiency of not less than 90%, and is used to supplement heating of the cracking furnace and drive the power generation device.

[0110] It should be noted that the waste heat generated by the cracking furnace described in this embodiment is recovered through an efficient multi-stage heat exchange system. In the first stage, the heat in the high-temperature exhaust gas is recovered to heat the feed part of the cracking furnace to maintain a stable reaction temperature; in the second stage, the recovered heat is used to drive the power generation device or supplement the energy of other systems to ensure that the heat recovery efficiency is not less than 90%. This heat recovery method greatly improves energy utilization efficiency, reduces dependence on external energy, and helps to reduce overall operating costs.

[0111] S6. Remove particulate matter, nitrogen oxides and sulfur dioxide from the exhaust gas through the exhaust gas purification system, ensuring that the particulate matter removal rate is not less than 95%, and the nitrogen oxide and sulfur dioxide emissions are less than 50ppm and 30ppm respectively.

[0112] It should be noted that the exhaust gas purification system described in this embodiment first uses a multi-stage filter to remove large particulate matter in the exhaust gas, then uses selective catalytic reduction (SCR) technology to further reduce nitrogen oxides, and removes sulfur dioxide through adsorption and catalytic technology to ensure that the removal rate of particulate matter in the exhaust gas is not less than 95%; at the same time, the system accurately controls the reaction conditions so that the emissions of nitrogen oxides and sulfur dioxide are less than 50ppm and 30ppm respectively, effectively reducing pollutant emissions and ensuring compliance with strict environmental emission standards.

[0113] Experimental Case

[0114] Experimental materials and equipment

[0115] Garbage sample: simulated domestic garbage, containing typical organic matter (40%), plastic (30%), rubber (10%), metal (5%) and other non-combustibles (15%), simulating the common components of domestic garbage.

[0116] Cracking unit:

[0117] Three-stage cracking furnace: The cracking furnace is equipped with three independent cracking zones, the temperatures of which can be adjusted separately (200-400℃, 400-600℃, 600-800℃), and has atmosphere adjustment function (oxygen-deficient, inert atmosphere, etc.).

[0118] Intelligent control system: The system integrates oxygen concentration sensor, temperature sensor, and gas composition analyzer, which can monitor and automatically adjust the temperature and atmosphere of each cracking area in real time to ensure cracking under optimal conditions.

[0119] Airflow isolation device: partition insulation and gas barrier to ensure that the atmosphere in different cracking zones is independently controllable.

[0120] Auxiliary equipment:

[0121] Multi-stage heat exchange system: used to recover the waste heat generated during the cracking process and use it to heat the cracking furnace or drive the generator set.

[0122] Gas collection and refining equipment: including condensers, filters and gas storage devices, processing cracking gas, purifying and recovering combustible gas.

[0123] Exhaust gas purification system: It uses a catalytic reduction device (SCR) and an activated carbon adsorption tower to remove particulate matter, nitrogen oxides (NOx) and sulfur dioxide (SO2) in the exhaust gas.

[0124] Metal Sorting Machine: Recover recyclable metals through physical magnetic separation and eddy current separation devices to improve metal recovery rate.

[0125] Experimental procedures and data collection

[0126] 1. Comparative experiment of cracking process

[0127] Control group: traditional single-stage pyrolysis (temperature set at 600°C, fixed oxygen-deficient atmosphere).

[0128] Experimental group: segmented anoxic lysis (performed according to the segmented parameters of claim 1, setting the temperature and atmosphere conditions separately).

[0129] Data collection:

[0130] Pyrolysis product quality: Collect and weigh gas, liquid and solid products.

[0131] Lysis time and energy consumption: Monitor the time consumed and the total energy required during the lysis process.

[0132] Harmful gas emissions: Collect and measure emission data of NOx, SO2, and particulate matter.

[0133] Comparison of cleavage efficiency and product (e.g. Figure 2 (shown)

[0134] Experimental improvements: For garbage with different compositions, the pyrolysis efficiency of organic matter, plastics and rubber is significantly improved by segmented control of atmosphere and temperature during the pyrolysis process. In particular, the pyrolysis effect of plastics and rubber is enhanced, and the recovery rate of solid carbonized products and combustible gases is also improved.

[0135] 2. Intelligent control system verification

[0136] During the staged cracking process, the oxygen concentration (0-5%) and temperature fluctuation (±10°C) are monitored in real time by the intelligent control system, and the injection amount of inert gas (N2, CO2) is automatically adjusted according to the real-time data.

[0137] Comparative experiment: Turn off the intelligent control system and manually control the cracking parameters to evaluate the optimization effect of the intelligent control system on the cracking process.

[0138] The impact of intelligent regulation on lysis efficiency (such as Figure 3 (shown)

[0139] Experimental improvement: The intelligent control system reduces temperature instability, improves the cracking rate of organic matter, significantly reduces the generation of harmful gases, and optimizes atmosphere control during the cracking process by real-time monitoring of temperature and oxygen concentration fluctuations.

[0140] 3. Exhaust gas purification and waste heat recovery test

[0141] Exhaust gas treatment: Exhaust gas is purified by a catalytic reduction (SCR) device and an activated carbon adsorption device to remove NOx, SO2 and particulate matter.

[0142] Waste heat recovery: The waste heat from the cracking process is recovered through a multi-stage heat exchange system and used to drive the generator set.

[0143] Environmental protection and energy recovery performance (such as Figure 4 (shown)

[0144] Experimental improvements: Through the efficient catalytic reduction technology of the exhaust gas purification system, NOx and SO2 emissions have been greatly reduced, and the particle removal rate has been increased to more than 95%. The waste heat recovery efficiency has been significantly improved, the power generation efficiency has been increased by more than 2 times, and the metal recovery rate has been increased to more than 90%.

[0145] Experimental Conclusion

[0146] Precise control: Segmented temperature control and intelligent adjustment enable different garbage components to be decomposed in the best environment, increasing the organic matter decomposition rate by more than 30%.

[0147] Emission reduction effect: The exhaust gas purification system reduces NOx and SO2 emissions to below 50ppm and 30ppm respectively, which is better than traditional incineration.

[0148] Energy optimization: waste heat recovery rate ≥ 90%, power generation efficiency increased by 120%, and metal recovery rate increased to more than 90%.

[0149] Specifically, efficient cracking of garbage is achieved by setting different temperatures and atmosphere conditions in different cracking zones. In the first cracking zone (200°C to 400°C, oxygen-deficient atmosphere), organic matter and volatiles are mainly cracked to generate low calorific value gases and liquid products; the second cracking zone (400°C to 600°C) reduces the generation of harmful gases while continuing to crack organic matter, producing solid carbonized products and some combustible gases; the third cracking zone (600°C to 800°C, inert atmosphere) mainly cracks synthetic materials such as plastics and rubber, and recovers gases and solid products. Through the intelligent control system, the temperature, atmosphere and oxygen concentration in the cracking process are monitored and adjusted in real time to ensure that each cracking zone is cracked under optimal conditions, thereby improving the cracking efficiency and reducing the emission of harmful gases. This technology solves the problems of inaccurate temperature control, excessive pollutant emissions and insufficient energy recovery in traditional cracking methods. Through precise segmented control, it not only improves the cracking efficiency, but also achieves the dual optimization of waste heat recovery and pollutant removal.

[0150] In one embodiment of the present invention, Figure 1-Figure 5As shown, the intelligent atmosphere control system adjusts the concentration of oxygen, nitrogen, carbon dioxide and other gases in the atmosphere through real-time data monitoring, so that each cracking area can achieve the best cracking efficiency.

[0151] It should be noted that the intelligent atmosphere control system described in this embodiment monitors the temperature, oxygen concentration, gas composition (such as nitrogen, carbon dioxide, etc.) and the flow state of the cracking gas in real time through a variety of sensors installed in the cracking furnace, and automatically adjusts the injection amount and flow rate of oxygen, nitrogen and carbon dioxide in combination with the data analysis algorithm, thereby ensuring that each cracking zone achieves the best cracking efficiency under the cracking reaction conditions at different stages, while optimizing energy utilization and reducing incomplete cracking or the generation of harmful gases.

[0152] Specifically, the intelligent atmosphere control system monitors the temperature, oxygen concentration, carbon dioxide, nitrogen and other gas components in the atmosphere in real time by installing multiple sensors in each cracking zone of the cracking furnace. The system continuously reads these real-time data through the data acquisition module and inputs them into the control unit for processing. The control unit automatically adjusts the injection amount and flow rate of oxygen, nitrogen or carbon dioxide through the preset algorithm and optimization model, combined with the different needs of the cracking process. For example, when the cracking temperature is high, the system will increase the injection of nitrogen or carbon dioxide to maintain a low oxygen concentration and optimize the high-temperature cracking process; while in the cracking zone with a lower temperature, the system will appropriately adjust the oxygen concentration to enhance the cracking efficiency of organic matter. Through this real-time adjustment, it is ensured that the atmosphere in each cracking zone is always in the optimal cracking conditions, improving the cracking efficiency and reducing the generation of harmful gases.

[0153] In one embodiment of the present invention, Figure 1-Figure 5 As shown, a gas flow isolation device is provided between the second cracking zone and the first cracking zone to ensure the stability of the atmosphere and temperature and to prevent cross-effects of heat or gas.

[0154] It should be noted that an airflow isolation device is arranged between the second cracking zone and the first cracking zone described in this embodiment. The device effectively prevents cross-interference of the atmosphere and temperature of different cracking zones through physical isolation and gas barrier mechanism, and adopts efficient thermal insulation materials and airflow control technology to ensure that the gas composition, temperature and atmosphere concentration in each cracking zone remain independent and stable, thereby avoiding the mutual transfer of heat or harmful gases, ensuring that each cracking zone operates efficiently under predetermined cracking conditions, and improving the overall cracking efficiency and product quality.

[0155] Specifically, the airflow isolation device is implemented in the following manner:

[0156] Thermal insulation wall:

[0157] Structure and principle: A high temperature resistant heat insulation wall is set between the first cracking zone and the second cracking zone. The wall is made of high temperature resistant materials (such as refractory bricks, ceramic fibers, aluminum silicate). The wall can effectively block the transfer of heat and prevent the heat generated in the first cracking zone from being transferred to the second cracking zone.

[0158] Function: The insulation wall not only prevents heat cross-effect, but also ensures that the reaction temperature in each cracking zone remains independent, avoiding unnecessary heat loss.

[0159] Air flow control valve and duct system:

[0160] Structure and principle: An airflow regulating valve and air duct system are set between the two cracking zones, and the airflow speed and direction in each cracking zone are controlled by adjusting the valve. The airflow regulating valve can automatically adjust the gas flow according to real-time data (temperature, atmosphere concentration, etc.).

[0161] Function: By precisely controlling the gas flow in each cracking zone, it is ensured that the gas flow in the first cracking zone and the second cracking zone will not cross. For example, the first cracking zone may require low oxygen or inert gas to maintain cracking conditions, while the second cracking zone may require an appropriate amount of oxygen to promote further cracking of organic matter.

[0162] Airflow Isolation Duct System:

[0163] Structure and principle: A double-layer isolation pipeline system is used, in which the inner pipeline is used for gas transmission, and the outer pipeline is used to prevent gas leakage and avoid mixing of atmospheres in different cracking areas. There may be a vacuum layer or an inert gas (such as nitrogen) filled between the two layers of pipelines to further enhance the gas flow isolation effect.

[0164] Function: This double-layer piping system ensures undisturbed gas flow and prevents cross-contamination of gas components between cracking zones.

[0165] Cyclone separator:

[0166] Structure and principle: Use a cyclone separator to separate the airflow in the two cracking zones. The cyclone separator separates the solid particles in the gas from the gas flow direction by rotating the airflow, thereby avoiding direct contact or mixing of the airflow.

[0167] Function: The cyclone separator can effectively isolate the flow paths of different gases, reduce the gas crossover between the two zones, and filter solid particles to prevent particle contamination.

[0168] Air distribution plate and air duct partition:

[0169] Structure and principle: Inside the cracking furnace, an air flow distribution plate and an air duct partition are set. The distribution plate can accurately distribute the air flow required by each cracking zone to ensure that the gas flow direction and flow rate of each cracking zone remain independent.

[0170] Function: The airflow in the first cracking zone can be completely separated from the airflow in the second cracking zone by the distribution plate and the air duct partition to prevent cross contamination and ensure independent control of the temperature and atmosphere in the two zones.

[0171] Therefore, the airflow isolation device ensures that the temperature and atmosphere between the first cracking zone and the second cracking zone are independent and stable through multiple technical means such as insulation walls, airflow regulating valves, double-layer isolation pipes, cyclone separators and airflow distribution plates, avoiding the cross-influence of heat or gas. These devices effectively guarantee the independent reaction conditions of each cracking zone and ensure the efficiency and stability of the cracking process.

[0172] Specifically, the airflow isolation device between the second cracking zone and the first cracking zone realizes independent atmosphere management of the two zones through physical isolation and gas flow control. The device adopts high-efficiency thermal insulation materials and sealing structures to ensure that heat and gas will not be transferred from one cracking zone to another. Specifically, the isolation device uses adjustable airflow valves and air duct systems to control the gas flow and atmosphere distribution inside each cracking zone, while avoiding cross-contamination of cracking gases. In the high-temperature area, the isolation device effectively prevents the high-temperature gas from diffusing to the low-temperature area, maintaining the stability of the cracking temperature; while in the low-oxygen or inert atmosphere area, it prevents oxygen or inert gas from entering other areas, ensuring that the atmosphere concentration in each cracking zone is at the optimal state and optimizing the cracking reaction effect.

[0173] In one embodiment of the present invention, Figure 1-Figure 5 As shown, the atmosphere in the cracking furnace can achieve cracking reactions in different temperature ranges by fine-tuning the oxygen concentration, ensuring that different garbage components are cracked in the most suitable environment.

[0174] It should be noted that the atmosphere in the cracking furnace described in this embodiment achieves cracking reactions in different temperature ranges by fine-tuning the oxygen concentration. Specifically, the system automatically adjusts the amount of oxygen injected by real-time monitoring the temperature and gas composition of the cracking zone, thereby creating an oxygen concentration suitable for the temperature and reaction requirements of the zone in different cracking zones. For example, in the low temperature zone (200°C-400°C), the slow cracking of organic matter is promoted by controlling the low oxygen concentration, while in the high temperature zone (600°C-800°C), the oxygen concentration is reduced to ensure that the inert atmosphere maintains the efficient progress of the cracking reaction, while preventing peroxidation and the generation of harmful gases. This adjustment method ensures that each garbage component is efficiently and comprehensively cracked under the most suitable atmosphere and temperature environment.

[0175] Specifically, the atmosphere in the cracking furnace achieves cracking reactions in different temperature ranges by fine-tuning the oxygen concentration. The specific principle is to use a real-time data monitoring system (including temperature sensors and oxygen concentration sensors) to monitor the temperature and gas composition in the cracking zone. According to the monitoring data, the control system automatically adjusts the amount of oxygen injection to maintain a low oxygen concentration in the low temperature zone (200℃-400℃) to promote the slow cracking of organic matter; in the medium temperature zone (400℃-600℃), the oxygen concentration is appropriately increased to increase the cracking rate and control the generation of harmful gases; in the high temperature zone (600℃-800℃), the oxygen concentration is reduced, and the cracking process is protected by an inert atmosphere (such as carbon dioxide or nitrogen) to prevent excessive oxidation reactions. This control mechanism ensures that each garbage component can be efficiently cracked under the most suitable temperature and atmosphere conditions.

[0176] In one embodiment of the present invention, Figure 1-Figure 5 As shown, the gas collection system includes a multi-stage filter and a condenser, which can recover harmful substances in the gas and extract high-quality fuel gas, and the recovery rate can reach more than 95%.

[0177] It should be noted that the gas collection system described in this embodiment effectively removes harmful substances generated during the cracking process through multi-stage filters and condensers. The filters first remove large particles and tiny particles through coarse filtration and fine filtration layers, and then further remove toxic gases and volatile organic compounds through an activated carbon adsorption layer. The condenser condenses and separates water vapor and liquefiable components in the gas to ensure that impurities in the gas are removed to the maximum extent. Finally, the recovered gas is refined to extract high-quality fuel gas, and the recovery rate can be as high as 95% or more, ensuring efficient recovery of resources and environmental protection.

[0178] The gas collection system recovers harmful substances from the gas and extracts high-quality fuel gas through the following specific devices and technologies:

[0179] Multi-stage filter:

[0180] Primary filter: Use a coarse filter or gas cyclone separator, mainly used to remove large particles (such as dust, solid particles, etc.) in the exhaust gas. These devices separate larger solid particles through centrifugal force or air flow cutting.

[0181] Intermediate filter: uses bag filter or electrostatic precipitator to remove small and medium-sized particles (such as PM10, PM2.5, etc.) to ensure that fine particles in the exhaust gas are captured and effectively removed.

[0182] Precision filter: Use high-efficiency particulate air (HEPA) filter or activated carbon filter to remove residual tiny particles, volatile organic compounds (VOCs) and other toxic and harmful gases to ensure complete gas purification.

[0183] Condenser:

[0184] Working principle: The condenser reduces the temperature of the exhaust gas, condenses the water vapor and other condensable substances in it into liquid and separates them from the gas. The condenser is usually composed of a cooling coil or a plate heat exchanger, and uses a cooling medium (such as water or liquid ammonia) to take away the heat in the exhaust gas and promote the condensation of water vapor.

[0185] Condensation process: The exhaust gas passes through the cooling pipe of the condenser, and the moisture and condensable components in the gas (such as hydrocarbon gas, methanol, etc.) are cooled and converted into liquid substances. These liquid substances are collected and stored for further energy recovery or chemical treatment.

[0186] Gas purification and recovery device:

[0187] Gas refining device: further purifies the condensed gas to remove impurities and trace harmful substances (such as sulfides, nitrogen oxides, etc.). Adsorption towers (such as activated carbon adsorption, molecular sieve adsorption) or chemical absorption devices (such as amine solution absorption) are usually used to remove harmful components in the gas.

[0188] High-quality fuel gas extraction: Through the gas refining process, the purified gas is converted into high-quality combustible gas (such as methane, hydrogen, etc.). These gases can be used for combustion, power generation or as chemical raw materials.

[0189] Device coordination and operation:

[0190] Multi-stage filter cooperates with condenser: Multi-stage filter first removes large and small particles in the exhaust gas to ensure that the cooling medium in the condenser is not polluted. The condenser further reduces the exhaust gas temperature, removes moisture and some organic components, and creates better conditions for gas refining and recovery.

[0191] Gas Recovery and Refining: The purified gas is processed through a refining unit to remove any residual harmful components, ensuring that the final recovered fuel gas is of high quality and suitable for energy production or industrial applications.

[0192] Therefore, the gas collection system combines multi-stage filters and condensers, first removing particulate matter and harmful gases in the exhaust gas through coarse, medium and fine filters, then separating water vapor and condensable components through the condenser, and finally extracting high-quality fuel gas through the gas purification device. The system effectively removes harmful substances, recovers high-quality fuel gas, and ensures the efficient operation of the system and the achievement of environmental protection standards.

[0193] Specifically, the working principle of the gas collection system is to remove harmful substances in the cracking gas through the combined action of a multi-stage filter and a condenser, and extract high-quality fuel gas. First, the cracking gas passes through a multi-stage filter, the first layer of coarse filter removes larger particles, then enters the fine filter layer to further remove fine particles and suspended matter, and finally passes through the activated carbon adsorption layer to remove toxic gases and volatile organic compounds. The filtered gas enters the condenser, which condenses and separates the water vapor and liquefiable components (such as light hydrocarbons) in the gas through low-temperature cooling, thereby reducing the moisture and impurities in the gas. Finally, the purified gas is purified and converted into high-quality fuel gas. The whole process ensures that the recovery rate of fuel gas reaches more than 95% and minimizes the emission of harmful substances.

[0194] In one embodiment of the present invention, Figure 1-Figure 5 As shown, the exhaust gas purification system includes catalytic reduction and adsorption devices, which can effectively remove harmful substances in the cracking process, ensure that the nitrogen oxide removal efficiency reaches more than 90%, and the sulfur dioxide removal efficiency reaches more than 85%. The waste heat generated in the cracking process can be recovered through the heat exchange system with a recovery rate of more than 90%, which can be used for further heating or power generation to improve the energy efficiency of the system. The metal recovery device recovers the metals generated in the cracking process through physical separation, ensuring the efficient recovery rate of the metals, and returns them to the production chain for reuse.

[0195] It should be noted that the exhaust gas purification system described in this embodiment combines catalytic reduction and adsorption devices. First, the catalytic reduction device efficiently catalytically reduces the nitrogen oxides and sulfur dioxide generated during the cracking process to convert them into harmless substances, ensuring that the removal efficiency of nitrogen oxides reaches more than 90% and the removal efficiency of sulfur dioxide reaches more than 85%; Subsequently, the activated carbon adsorption device further adsorbs the residual harmful gases and particulate matter to ensure that the exhaust gas meets environmental protection standards. During the cracking process, the waste heat generated is recovered by an efficient heat exchange system. The system increases the waste heat recovery rate to more than 90% through multi-stage heat exchange. These waste heats can be used to further heat the cracking furnace or drive the generator set to improve the overall energy efficiency of the system. In addition, the metal recovery device efficiently recovers the metal substances generated during the cracking process through physical separation technology (such as magnetic separation and eddy current separation), and sends them back to the production chain for reuse, thereby maximizing the recovery efficiency of resources and reducing waste.

[0196] The specific working principle of the exhaust gas purification system.

[0197] The catalytic reduction device comprises a catalytic bed filled with titanium-based catalysts, vanadium-based catalysts or aluminum-based catalysts, etc. These catalysts can promote reduction reactions within a certain temperature range.

[0198] Nitrogen oxide reduction reaction: Nitrogen oxides (NOx) react with a reducing agent (such as ammonia or urea) to produce nitrogen (N2) and water (H2O).

[0199] Sulfur dioxide reduction reaction: Sulfur dioxide reacts with oxygen to form sulfur dioxide oxides, which are further reduced to harmless substances by a catalyst.

[0200] Device configuration:

[0201] Reactor design: The reactor adopts a layered catalytic bed. When the gas flows through the catalytic bed, it reacts with the catalyst to remove harmful substances in the exhaust gas.

[0202] Temperature control: Catalytic reduction units work best in the temperature range of 300°C to 500°C, so the reactor is equipped with a temperature control system to ensure that the catalytic reaction takes place at the ideal temperature.

[0203] Effect: Catalytic reduction devices can efficiently remove nitrogen oxides and sulfur dioxide, usually with a removal efficiency of more than 90%, thereby significantly reducing harmful emissions in exhaust gas.

[0204] Adsorption device: activated carbon adsorption or molecular sieve adsorption.

[0205] The synergy between the two:

[0206] Exhaust gas flow: The exhaust gas first enters the catalytic reduction device, where harmful gases such as nitrogen oxides and sulfur dioxide are reduced and converted into harmless substances. Then, the exhaust gas after catalytic reduction treatment enters the adsorption device, and the adsorption tower further removes volatile organic compounds, heavy metals and other trace harmful gases.

[0207] Working in synergy: The catalytic reduction device is combined with the adsorption device to remove trace pollutants from the source, ensuring that the exhaust gas purification achieves high efficiency and low emission results.

[0208] Overall effect guarantee:

[0209] The combination of catalytic reduction and adsorption ensures that the exhaust gas purification system can comprehensively remove most harmful gases and ensure that emissions meet environmental standards.

[0210] Temperature control: Catalytic reduction devices require temperature control systems to ensure optimal reaction, while adsorption devices rely on the selection and replacement of adsorption materials to ensure long-term and efficient operation.

[0211] Intelligent monitoring: The exhaust gas purification system is usually equipped with an intelligent monitoring system to monitor the exhaust gas composition, temperature, pressure, etc. in real time, and automatically adjust the working status of the catalytic reduction device and adsorption device to ensure the best purification effect.

[0212] Therefore, the exhaust gas purification system can effectively remove harmful substances such as nitrogen oxides, sulfur dioxide, volatile organic compounds and heavy metals through the coordinated work of catalytic reduction and adsorption devices, ensuring that emissions meet environmental standards. The catalytic reduction device converts harmful gases through catalytic reactions, while the adsorption device removes trace pollutants through adsorption. The two work together to ensure the thorough purification of exhaust gas and environmentally compliant emissions.

[0213] Specifically, the working principle of the exhaust gas purification system is to effectively remove harmful substances generated during the cracking process through two-stage treatment. First, the exhaust gas enters the catalytic reduction device. Under high temperature conditions, the catalyst promotes the reaction of nitrogen oxides (NOx) and sulfur dioxide (SO2) with the reducing gas and converts them into harmless nitrogen and water vapor, thereby ensuring that the nitrogen oxide removal efficiency reaches more than 90% and the sulfur dioxide removal efficiency reaches more than 85%. After that, the purified exhaust gas passes through the activated carbon adsorption device, and the adsorption layer captures the remaining harmful gases, particulate matter and volatile organic compounds (VOCs), further removing pollutants in the exhaust gas to ensure that the emissions meet environmental standards. At the same time, the waste heat generated during the cracking process is recovered through a multi-stage heat exchange system, which transfers the waste heat to the cold fluid through a heat exchanger, with a recovery rate of more than 90%. The recovered heat is used for reheating the cracking furnace or driving the generator set, thereby improving the energy efficiency of the entire system. The metal recovery device adopts physical separation technology, using magnetic separation and eddy current separation devices to separate the metal substances produced in the cracking process, ensuring a high efficiency of metal recovery. The recovered metal is returned to the production chain for reuse, minimizing resource waste and improving resource utilization.

[0214] In summary, the staged anoxic pyrolysis method for domestic waste in the embodiment of the present invention divides domestic waste into multiple pyrolysis zones through staged anoxic pyrolysis technology. Each pyrolysis zone optimizes the pyrolysis process according to the temperature and atmosphere to ensure that different waste components are efficiently pyrolyzed under the most suitable conditions. The intelligent atmosphere control system monitors and adjusts the temperature, oxygen concentration and gas composition in the pyrolysis zone in real time to ensure pyrolysis efficiency and environmental performance. The waste gas purification system adopts catalytic reduction and adsorption devices to remove nitrogen oxides, sulfur dioxide and particulate matter to ensure that emissions meet environmental standards. At the same time, the waste heat recovery system recovers waste heat in the pyrolysis process through multi-stage heat exchange, and the recovery rate reaches more than 90%, which is used to heat the pyrolysis furnace or generate electricity to improve the energy efficiency of the system. In addition, the metal recovery device recovers the metals generated in the pyrolysis process through physical separation technology, improves the resource recovery rate and realizes reuse. Through these technical innovations, the present invention effectively solves the problems of low pyrolysis efficiency, high pollution emissions, insufficient energy efficiency and resource waste in the background technology, and realizes efficient, environmentally friendly and resource-based waste treatment.

[0215] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and deform the above embodiments within the scope of the present invention.

Claims

1. A staged anoxic pyrolysis method for domestic waste, characterized in that: The following steps are involved: S1. Put the domestic waste into the cracking furnace in sections. The cracking furnace is equipped with at least three independent cracking zones. The temperature, atmosphere and oxygen concentration of each cracking zone can be intelligently adjusted according to real-time monitoring data; S2, the temperature of the first cracking zone is 200℃ to 400℃, the atmosphere is in an oxygen-deficient state, organic matter and volatile matter are preferentially cracked to produce low calorific value gas and liquid products, the temperature of the second cracking zone is 400℃ to 600℃, the remaining organic matter is further cracked in an oxygen-deficient atmosphere, the generation of harmful gases is reduced, and it is converted into solid carbonized products and part of the combustible gas, the temperature of the third cracking zone is 600℃ to 800℃, plastics, rubber and other synthetic materials are cracked in an inert atmosphere, gas and solid products are recovered, and efficient energy recovery is ensured; S3. During the cracking process, the intelligent atmosphere control system automatically adjusts the atmosphere and temperature of each cracking zone according to real-time data monitoring to optimize the cracking efficiency and reduce harmful emissions; S4. The combustible gas and liquid products produced during the cracking process are collected and refined separately to generate high-quality fuel gas and oil products, with a recovery rate of more than 90%; S5. The waste heat generated by the cracking furnace is recovered through a multi-stage heat exchange system with a recovery efficiency of not less than 90%, and is used to supplement heating of the cracking furnace and drive the power generation device; S6. Remove particulate matter, nitrogen oxides and sulfur dioxide from the exhaust gas through the exhaust gas purification system, ensuring that the particulate matter removal rate is not less than 95%, and the nitrogen oxide and sulfur dioxide emissions are less than 50ppm and 30ppm respectively.

2. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: The intelligent atmosphere control system adjusts the concentration of oxygen, nitrogen, carbon dioxide and other gases in the atmosphere through real-time data monitoring.

3. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: An airflow isolation device is arranged between the second cracking zone and the first cracking zone to ensure the stability of the atmosphere and temperature and to prevent cross influence of heat or gas.

4. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: The atmosphere in the cracking furnace can achieve cracking reactions in different temperature ranges by fine-tuning the oxygen concentration, so that the garbage components can be cracked in the most suitable environment.

5. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: The gas collection system includes multi-stage filters and condensers, which can recover harmful substances in the gas and extract high-quality fuel gas.

6. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: The exhaust gas purification system includes catalytic reduction and adsorption devices to effectively remove harmful substances in the cracking process.

7. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: The waste heat generated during the cracking process can be recovered through a heat exchange system and used for further heating or power generation, thereby improving the energy efficiency of the system.

8. The method for staged anoxic pyrolysis of domestic waste according to claim 1, characterized in that: The metal recovery unit recovers the metals generated during the cracking process by physical separation, ensuring a high metal recovery rate and returning them to the production chain for reuse.

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