Method for judging and optimizing raw material ratio in microwave synergistic pyrolysis

Abstract

The invention discloses a method for judging and optimizing a raw material ratio in microwave synergistic pyrolysis, and relates to the technical field of solid waste recycling and biomass energy utilization. In order to overcome the defect that in-depth research and engineering application of a microwave pyrolysis process are restricted in the prior art, the technical scheme provided by the invention comprises the following steps: preparing samples from oily sludge and palm kernel shells according to a preset mass ratio, and mixing to obtain a mixed raw material; establishing an inert atmosphere and forming a controlled reaction system; applying microwave heating and collecting a sample mass change curve and temperature change data; comparing the mass change curve with a theoretical curve formed by weighted stacking of a single raw material pyrolysis curve to obtain a difference result; judging the synergistic effect strength among the raw materials according to the difference result, and outputting a synergistic effect judgment result; and determining an optimal ratio based on a synergistic effect judgment result. The method is suitable for raw material ratio judgment and optimization work of solid waste and biomass under the microwave synergistic pyrolysis condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid waste resource utilization and biomass energy utilization, and particularly relates to a method for determining and optimizing the ratio of raw materials in microwave-assisted co-pyrolysis. BACKGROUND

[0002] Energy utilization of solid wastes such as biomass, oily sludge, plastic waste and coal has gradually become a research focus. Among them, co-pyrolysis technology has become an important direction for solid waste resource utilization because it can play a complementary role among raw materials during the reaction process, improve the quality of single raw material pyrolysis products and improve the overall energy efficiency. A large number of research results show that different raw materials may exhibit a promoting effect or an inhibitory effect in the co-pyrolysis process. This effect directly affects the yield and quality of products such as bio-oil, combustible gas and biochar. Its form and intensity not only depend on the type of raw materials, but also are closely related to the ratio of raw materials. At a suitable ratio, the hydrogen donor effect, free radical transfer or ash catalytic effect among raw materials can strengthen the reaction process, showing a promoting effect. When the ratio is not appropriate, the inhibitory effect may occur due to heat transfer obstruction, increased side reactions or insufficient active components. Therefore, how to determine the type and intensity of the interaction of different raw materials at different ratios and further determine the optimal ratio is a key problem in co-pyrolysis research and application.

[0003] Current co-pyrolysis research is mainly based on conventional heating methods such as tube furnaces or resistance furnaces. Researchers usually determine whether there is a synergistic effect by comparing the yield, component composition and physicochemical properties of the products at different ratios. This determination method has been applied to some extent in laboratory research, but has obvious limitations: first, the research method mainly relies on end-point analysis of the products, lacking a description of the dynamic changes in the reaction process; second, the determination of synergistic effect often stays at the qualitative or empirical judgment level, making it difficult to achieve objective and unified standards; third, the experimental process needs to cover multiple ratios, resulting in large experimental workload and long experimental period. At the same time, microwave heating is gradually introduced into the field of co-pyrolysis due to its fast heating rate, high energy utilization efficiency and selective absorption. However, the response of materials under microwave heating is significantly different from that under conventional heating methods, and the synergistic or inhibitory effect among raw materials shows more complex nonlinear rules, and the existing determination methods based on conventional methods cannot fully adapt to this feature.

[0004] In summary, in the research of microwave-assisted co-pyrolysis, the ratio determination and optimization of the interaction among raw materials have not been effectively solved, which to a great extent restricts the in-depth research and engineering application of microwave pyrolysis process. SUMMARY

[0005] To solve the problems of the ratio determination and optimization of the interaction between raw materials in the prior art, which restricts the in-depth research and engineering application of the microwave pyrolysis process, the technical scheme provided by the present application is: A method for determining and optimizing the ratio of raw materials in microwave-assisted pyrolysis, comprising: A step of preparing and mixing oil-containing sludge and palm kernel shell according to a preset mass ratio to obtain mixed raw materials; A step of loading the mixed raw materials into a quartz crucible and introducing high-purity nitrogen into a microwave pyrolysis device to establish an inert atmosphere and form a controlled reaction system; A step of applying microwave heating to the controlled reaction system and collecting sample mass change curves and temperature change data; A step of comparing the mass change curve with a theoretical curve formed by weighted superposition of single raw material pyrolysis curves to obtain a difference result; A step of determining the strength of the synergistic effect between raw materials according to the difference result and outputting a synergistic effect determination result; A step of determining the optimal ratio based on the synergistic effect determination result and outputting an optimization conclusion.

[0006] Further, an preferred embodiment is provided, the oil-containing sludge is derived from a petrochemical wastewater treatment system, dried to control the water content below 5% and ground to a particle size less than 100 microns, and the palm kernel shell is dried and crushed and sieved to a particle size less than 200 microns.

[0007] Further, an preferred embodiment is provided, the frequency of microwave heating is 2450 MHz, the microwave power is adjustable from 0 to 1500 watts, the heating rate is controlled at 10 degrees Celsius per minute, the final temperature is 600 degrees Celsius and is maintained for 10 minutes, and the atmosphere is high-purity nitrogen with a flow rate controlled at 100 to 600 milliliters per minute.

[0008] Further, an preferred embodiment is provided, the data acquisition system records the sample mass change at intervals of every 10 seconds to form thermogravimetric curves and differential thermogravimetric curves, and combines a temperature feedback module to realize dynamic monitoring of the reaction process.

[0009] Further, an preferred embodiment is provided, the difference result is obtained by extracting the pyrolysis curves of pure oil-containing sludge and pure palm kernel shell as controls, calculating the theoretical additive curve according to the mass fraction of each in the mixed system, comparing the theoretical additive curve with the experimental curve of the mixed raw materials, and determining positive synergistic effect if the mass loss of the experimental curve is faster than the theoretical curve, and determining inhibitory effect if it is slower than the theoretical curve.

[0010] Further, a preferred embodiment is provided, and the optimization conclusion is that the strongest positive synergistic effect is obtained when the mass ratio of oily sludge to palm kernel shell is 1:1, which shows the improvement of bio-oil and combustible gas yield and the optimization of reaction rate.

[0011] A device for determining and optimizing the ratio of raw materials in microwave-assisted pyrolysis is also provided, comprising: A module for preparing and mixing oily sludge and palm kernel shell according to a preset mass ratio to obtain mixed raw materials; A module for loading the mixed raw materials into a quartz crucible and introducing high-purity nitrogen into a microwave pyrolysis device to establish an inert atmosphere and form a controlled reaction system; A module for applying microwave heating to the controlled reaction system and collecting sample mass change curves and temperature change data; A module for comparing the mass change curve with a theoretical curve formed by weighted superposition of single raw material pyrolysis curves to obtain difference results; A module for determining the strength of synergistic effect between raw materials according to the difference results and outputting the synergistic effect determination results; A module for determining the optimal ratio based on the synergistic effect determination results and outputting the optimization conclusion.

[0012] A computer storage medium for storing a computer program is also provided, and when the computer program is read by a computer, the computer executes the method.

[0013] A computer comprising a processor and a storage medium is also provided, and when the processor reads the computer program stored in the storage medium, the computer executes the method.

[0014] A computer program product is also provided as a computer program, and when the computer program is executed, the method is implemented.

[0015] Compared with the prior art, the technical solution provided by the present application has the following advantages: The present application realizes quantitative identification of raw material synergistic effect by establishing a synergistic criterion AW based on the difference in thermogravimetric curves. This criterion can directly compare the difference between the experimental thermogravimetric curve and the theoretical additive curve, thereby reflecting the strength of the promoting or inhibiting effect in the system. Unlike the prior art, which relies only on product yield or component changes to infer, this method can be dynamically evaluated during the reaction process, making the judgment of synergistic effect more objective and accurate.

[0016] The application realizes non-contact real-time weighing of the sample in the microwave heating process by adopting the design of a quartz support combined with an online electronic balance on an experimental device. This mode avoids the deficiency that only limited information can be obtained by end-point weighing in traditional experiments, and can obtain a continuous mass change curve throughout the whole process, significantly improving the ability to grasp the dynamic process of the reaction, thereby enhancing the scientific nature of the ratio optimization.

[0017] The application realizes dynamic monitoring of the pyrolysis process by introducing a temperature real-time feedback and mass synchronous acquisition system in the microwave pyrolysis platform. Compared with conventional tube furnace experiments, this mode can avoid experimental errors caused by uneven temperature distribution or different heating methods, providing data support closer to actual reaction conditions for the determination of raw material synergistic effect, thereby ensuring the accuracy and repeatability of the experimental results.

[0018] The application adopts oil-containing sludge and palm kernel shell as representative raw materials, selects the best ratio scheme by setting different mass ratios and performing differential thermogravimetric analysis. Compared with the existing method of relying on a large number of parallel experiments to find an empirical ratio, this mode can quickly lock the optimal ratio by calculating ΔW, greatly reducing the number and period of experiments, reducing research costs and improving efficiency.

[0019] The ratio optimization method based on dynamic thermogravimetric difference proposed by the application has universality and can be extended to other biomass, plastic, coal and solid waste synergistic pyrolysis systems. Unlike the single empirical rule established for a specific raw material system in existing research, this mode provides a unified scientific criterion for complex multi-component systems, making the optimization path more expandable and universal, thereby improving the reliability of process design and engineering application.

[0020] It is suitable for raw material ratio determination and optimization of solid waste and biomass under microwave synergistic pyrolysis conditions. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of a microwave pyrolysis system, Among them, 1 is a flow meter, 2 is a K-type thermocouple, 3 is a microwave oven main machine and a control panel, 4 is a quartz crucible, 5 is a quartz support, 6 is a quartz cover, 7 is an analytical balance, 8 is a data acquisition system, 9 is a condensation and gas collection system, and 10 is an emergency stop button. DETAILED DESCRIPTION

[0022] In order to make the advantages and benefits of the technical solutions provided by the application more clear, the technical solutions provided by the application will be further described in detail in conjunction with the drawings. Specifically: Embodiment one, the embodiment provides a method for determining and optimizing the ratio of raw materials in microwave synergistic pyrolysis, comprising: a step of preparing and mixing oil sludge and palm kernel shell according to a preset mass ratio to obtain mixed raw materials; a step of loading the mixed raw materials into a quartz crucible and introducing high-purity nitrogen into a microwave pyrolysis device to establish an inert atmosphere and form a controlled reaction system; a step of applying microwave heating to the controlled reaction system and collecting sample mass change curves and temperature change data; a step of comparing the mass change curve with a theoretical curve formed by weighted superposition of single raw material pyrolysis curves to obtain a difference result; a step of determining the strength of the synergistic effect between the raw materials according to the difference result and outputting a synergistic effect determination result; a step of determining an optimal ratio based on the synergistic effect determination result and outputting an optimization conclusion.

[0023] The oil sludge is derived from a petrochemical wastewater treatment system, dried to control the water content to be below 5%, and ground to a particle size of less than 100 microns. The palm kernel shell is dried and crushed and sieved to a particle size of less than 200 microns.

[0024] The frequency of microwave heating is 2450 MHz, the microwave power is adjustable from 0 to 1500 watts, the heating rate is controlled at 10 degrees Celsius per minute, the final temperature is 600 degrees Celsius and is maintained for 10 minutes, and the atmosphere is high-purity nitrogen with a flow rate controlled at 100 to 600 milliliters per minute.

[0025] The data acquisition system records the sample mass change at intervals of every 10 seconds to form thermogravimetric curves and differential thermogravimetric curves, and realizes dynamic monitoring of the reaction process in combination with a temperature feedback module.

[0026] The difference result is obtained by extracting the pyrolysis curves of pure oil sludge and pure palm kernel shell as controls, calculating the theoretical additive curve according to the mass fraction of each in the mixed system, comparing the theoretical additive curve with the experimental curve of the mixed raw materials, and determining a positive synergistic effect if the experimental curve loses mass faster than the theoretical curve, or an inhibitory effect if it loses mass slower than the theoretical curve.

[0027] The optimization conclusion is that the strongest positive synergistic effect is obtained when the mass ratio of oil sludge to palm kernel shell is 1:1, which is manifested as an increase in the yield of bio-oil and combustible gas and an optimization of the reaction rate.

[0028] Embodiment Two, this embodiment is a further detailed description of the technical solution provided in Embodiment One, specifically: The microwave synergistic pyrolysis raw material ratio determination and optimization method proposed by the present application is described in detail in combination with a representative raw material system of oil sludge (OS) and palm kernel shell (PKS).

[0029] First, sample preparation and proportioning setup. The oily sludge is selected from the wastewater treatment system of a petrochemical enterprise, mainly composed of heavy hydrocarbons, organic impurities and a certain proportion of inorganic sediments. In order to ensure the stability of the experiment, the oily sludge is first dried to reduce the water content to less than 5%, and then ground to a particle size of less than 100 microns. Palm kernel shell, as a typical agricultural waste, is rich in cellulose and lignin, with high carbon content and good microwave absorption capacity. After drying, it is crushed and sieved to a particle size of less than 200 microns. According to the research needs, five groups of proportions are set, including pure PKS (1:0), pure OS (0:1), PKS and OS mixed in the proportions of 3:1, 1:1 and 1:3, and the total mass of the sample is controlled at 50 grams. By mixing thoroughly, the uniformity of different proportions is ensured, providing conditions for subsequent experiments. The output of this step is different sample groups of different proportions, laying the foundation for the synergistic pyrolysis experiment.

[0030] Next, the mixed sample is loaded into a quartz crucible and fixed at the center of the microwave cavity by a quartz support. The microwave experimental platform includes a flow meter, a temperature measurement module, a microwave main machine, a real-time weighing system and a condensation collection system. Before the experiment, high-purity nitrogen is introduced at a flow rate of 100 milliliters per minute to establish an inert atmosphere and avoid secondary oxidation reaction interference with the experimental results. Unlike traditional tube furnaces, this system can realize real-time feedback of temperature and dynamic monitoring of sample mass under microwave heating conditions, ensuring stable and controllable experimental environment. The output of this step is a ready-to-use experimental system, providing controlled conditions for the pyrolysis process.

[0031] Then, set the microwave heating program. The microwave power is adjustable between 0 and 1500 watts, with a frequency of 2450 megahertz. According to the linear power heating strategy, the sample temperature is raised to 600 degrees Celsius at a rate of about 10 degrees Celsius per minute, and maintained at the final temperature for 10 minutes. During this process, the K-type thermocouple feeds back the temperature in the reaction cavity to the control module in real time, achieving precise control of the heating rate and temperature platform. At the same time, the quartz support is connected to the electronic balance, which can record the subtle changes in sample mass in real time, and the data is transmitted to the acquisition system at a frequency of every 10 seconds, forming complete thermogravimetric curves and differential thermogravimetric curves. The output of this step is high-resolution mass and temperature change data, ensuring accurate characterization of the dynamics of the pyrolysis process.

[0032] Subsequently, the generated multiphase products are processed. The volatile gases released during pyrolysis enter a series of condensers through the top outlet, and the condensed products are collected in a condenser bottle as bio-oil, while the non-condensable gases are discharged into a tail gas absorption unit to avoid environmental emissions. The residual solid product remains in the quartz crucible, which is the biochar. This product separation process ensures clear definition of the gas, liquid, and solid three-phase products during the experiment and provides data support for subsequent evaluation of the energy conversion efficiency of different ratios. The output of this step is the separation and collection of products, which provides the basis for further analysis of the pyrolysis results.

[0033] Next, the mass change curves obtained from the experiment are compared and analyzed. First, the pyrolysis curves of pure OS and pure PKS are extracted, which reflect their weight loss rules and pyrolysis characteristics under microwave heating conditions. According to these two curves and their mass proportions in the mixed system, a theoretical additive curve is calculated, which represents the mass loss trend assuming that there is no synergistic effect between the raw materials. Comparing the theoretical curve with the actual experimental curve of the mixed system, if the mass loss rate of the experimental curve is faster than the predicted value, it indicates that there is a promoting effect in the system; if it is slower than the predicted value, it indicates that there is an inhibitory effect in the system. The output of this step is the determination result of the synergistic effect under different ratios.

[0034] Finally, the strength of the synergistic effect under different ratios is quantitatively evaluated. The experimental results show that when the ratio of PKS to OS is 1:1, the difference between the actual curve and the theoretical curve is most significant, with the experimental mass loss being faster, indicating the strongest positive synergistic effect at this ratio. The corresponding results are that the yield of bio-oil and combustible gas is significantly improved, the reaction rate is best, and the structure of the biochar is more stable. Compared with existing optimization methods that rely on a large number of experiments and empirical judgments, the present invention can quickly determine the optimal ratio through a small number of experiments, thereby significantly reducing the experimental period and energy consumption, and improving the process optimization efficiency. The output of this step is the clear conclusion of the optimal ratio, which provides a reliable basis for industrial application.

[0035] In summary, the present invention establishes a method that can dynamically quantify the synergistic effect and optimize the raw material ratio through the organic connection of sample preparation, microwave experiment, real-time data acquisition, product separation, and synergistic effect determination. This method is not only suitable for the system of oil-containing sludge and palm kernel shell, but also can be extended to various combinations of biomass and coal, biomass and plastic, etc., providing a scientific tool and theoretical support for the process design of complex solid waste synergistic pyrolysis.

[0036] Embodiment three, combination Figure 1 To illustrate the present embodiment, the above-mentioned technical solutions are further described in detail through specific embodiments, specifically: Although existing co-pyrolysis research has confirmed that different raw materials and ratios have a significant impact on product distribution and quality, there are still obvious deficiencies in actual determination and optimization: first, conventional research mainly relies on product yield and composition comparison to indirectly determine the synergistic effect, which requires a large number of experiments to cover different ratios, with long experimental periods and high costs; second, existing determination methods lack a unified quantitative index, and the results often rely on empirical judgment, making it difficult to ensure objectivity and repeatability; third, the response mechanism of raw materials under microwave heating conditions is fundamentally different from traditional heating methods, and existing methods cannot truly reflect the promotion or inhibition of different ratios in microwave co-pyrolysis, nor can they provide effective basis for raw material ratio optimization.

[0037] The present application aims to solve the problems of lack of scientific quantitative basis for raw material ratio optimization in microwave co-pyrolysis system and difficulty in systematic identification of synergistic effect. Therefore, the present application proposes a synergistic analysis method based on thermogravimetric behavior under microwave heating conditions, and constructs an analysis model of the difference between experimental mass change curve and theoretical superposition curve. By comparing the dynamic deviation of the two, it is determined whether there is synergistic enhancement or pyrolysis inhibition in the mixed system.

[0038] To solve the above problems, the present application aims to propose a method for determining and optimizing the ratio of raw materials in co-pyrolysis under microwave heating conditions. By establishing a quantitative analysis method based on experimental thermogravimetric data, the synergistic or inhibitory effect under different proportions is quickly determined, and the optimal ratio is determined, thereby overcoming the defects of existing methods such as large amount of experiments, low efficiency, strong subjectivity of determination and inapplicability to microwave pyrolysis. The present application provides a scientific basis for the research and engineering application of microwave co-pyrolysis process.

[0039] The technical measures taken to solve the above technical problems are as follows: The method uses a microwave pyrolysis experimental platform to perform pyrolysis experiments on raw materials such as oil sludge and palm kernel shells in different ratios, collects mass change data in real time, and performs numerical fitting and deviation analysis on the thermogravimetric curve. By establishing a synergistic effect criterion and quantitatively evaluating the difference area, the interaction strength between raw materials under different ratios is identified, and the optimal mass ratio combination is selected, thereby providing theoretical support and data basis for process design, parameter optimization and industrial application of co-pyrolysis process.

[0040] (1) Reaction raw materials The present application uses two typical solid wastes as starting raw materials: Oil sludge (OS): derived from wastewater treatment system of petrochemical enterprises, mainly containing heavy hydrocarbons, organic impurities and inorganic sediments, with water content controlled below 5%, dried and ground to particle size <100 μm.

[0041] Palm kernel shell (PKS): It is an agricultural waste, rich in cellulose and lignin, with high carbon content and good wavelength absorption efficiency. After drying, crushing and screening, the particle size is <200 μm.

[0042] The two raw materials were mixed in a set mass ratio (e.g. 3:1, 1:1, 1:3, etc.), and after being mixed evenly, they were used for the synergistic pyrolysis experiment. The total mass of all experimental samples was uniformly controlled at 50 g.

[0043] (2) Reaction equipment and device structure The method relies on a set of experimental microwave pyrolysis system, as shown in Figure 1 , the specific structure includes: Flow meter 1: used for accurately controlling the nitrogen flow into the reaction cavity, maintaining the inert atmosphere during the reaction process; K-type thermocouple 2: used for real-time measurement of the temperature of the reactants in the quartz crucible, with data feedback to the temperature control system; Microwave oven main machine and control panel 3: including liquid crystal display screen, temperature control adjustment knob and emergency stop button 10, controlling the microwave source with a frequency of 2450 MHz and a power of 0-1500 W; Quartz crucible 4 is used to hold mixed reaction raw materials and is placed on the middle platform.

[0044] Quartz support frame 5: supports the bottom of the quartz crucible and is connected to the mass monitoring system.

[0045] Quartz cover 6: set outside the quartz crucible and quartz support, serving to isolate airflow disturbance, shield microwave leakage, prevent external impurities from entering, and stabilize the temperature field inside the cavity.

[0046] Analytical balance 7: used for real-time recording of the mass change of the sample (with an accuracy of 0.1 mg) and outputting data to the data acquisition system; Data acquisition system 8: automatic sampling frequency is 10 s, forming thermogravimetric (TG) and differential thermogravimetric (DTG) curves; Condensation and gas collection system 9: used for capturing bio-oil and non-condensable gas generated during the pyrolysis process.

[0047] The connection relationship between each structure is as follows: the quartz reaction tube is fixed in the center of the microwave cavity, connected to the analytical balance 7 through the quartz support frame 5 passing through the bottom of the cavity; the output signal of the analytical balance 7 is collected by the data acquisition module; and an inert gas channel is provided at the top.

[0048] (3) Adaptation of reaction conditions and raw material characteristics The device supports the following experimental conditions: Atmosphere: high-purity nitrogen (99.999%), 600 mL / min; Temperature control range: room temperature to 1100°C; Sample mass: 50 g; Microwave power: 0-1500 W continuously adjustable; Heating mode: non-contact direct heating by microwave radiation; Detection frequency: mass collection interval of 10 s, continuous recording period can be set.

[0049] Specifically: The microwave pyrolysis system is an experimental device, which is composed of an atmosphere control module, a reaction heating module, an online monitoring module, and a product collection module. The structure and configuration are as follows: 1. Atmosphere control module The system is equipped with a high-purity nitrogen cylinder as a protective gas source. The nitrogen flow is precisely controlled by a flow meter, and the normal flow range is 100-600 mL / min. Nitrogen enters the reaction cavity, which can form a stable inert atmosphere during pyrolysis, preventing the sample from being oxidized or undergoing secondary reactions.

[0050] 2. Reaction heating module The core heating unit is a microwave oven main machine with a working frequency of 2450 MHz and an output power of 0-1500 W continuously adjustable. The control panel is equipped with a temperature control adjustment knob, a liquid crystal display, and an emergency stop button 10, which facilitates real-time adjustment of experimental conditions and ensures operation safety. The reaction zone is centrally provided with a quartz crucible for holding raw materials. The crucible is fixed in the center of the cavity by a quartz support to ensure uniform distribution of the microwave field and avoid local overheating caused by positional deviation. A quartz cover is placed outside the crucible to isolate airflow disturbance, shield microwave leakage, and stabilize the temperature field.

[0051] 3. Online monitoring module To obtain real-time parameters during the reaction, the system is equipped with a K-type thermocouple that is inserted into the interior of the quartz crucible or near the surface of the reactant. It measures the reaction temperature in real time and feeds back to the temperature control system, thereby achieving precise temperature control. The quartz support penetrates the bottom of the cavity and is connected to a high-precision electronic balance, allowing the sample to be dynamically weighed during the reaction with a weighing accuracy of 0.1 mg. The electronic balance signal is transmitted to the computer through the data acquisition system. The system automatically collects data at an interval of 10 seconds, generates thermogravimetric (TG) and differential thermogravimetric (DTG) curves, and realizes continuous monitoring of the reaction kinetics.

[0052] 4. Product collection module The volatile products generated during the reaction pass through the top outlet into the condensation system. The condensation device is composed of two-stage vertical condensers, and the condensation water inlet and outlet are connected with the constant temperature circulating water tank respectively for maintaining stable cooling conditions. After cooling, the gas is liquefied into bio-oil and collected in the lower condensation bottle, and the uncondensed combustible gas enters the tail gas absorption unit to avoid direct emission to the environment. The module can realize effective separation and collection of liquid and gas phase products, and facilitate further qualitative and quantitative analysis of the products.

[0053] 5. System linkage and safety design The entire system is linked and controlled through data acquisition and analysis software, which can simultaneously display key parameters such as temperature, mass change and atmosphere flow, ensuring the consistency and integrity of experimental data. In addition, the control panel is provided with an emergency stop button 10, which can immediately cut off the microwave power when the system appears abnormal, ensuring the safety of the experimenters.

[0054] The core improvement of the present application is to propose a raw material collaborative determination and ratio optimization method suitable for microwave pyrolysis system, and to build a thermogravimetric difference analysis mechanism that can quantify the synergistic effect in thermogravimetric experiments. Unlike traditional methods that rely on empirical ratio or single indicators of product yield for optimization, the present application first introduces a synergistic criterion ΔW based on the difference in mass loss rate. By performing difference analysis on the mass change curves of oil sludge and palm shell mixtures at different proportions, the quantitative expression of synergistic strength is realized, and the optimal ratio interval is accurately identified. This method has wide applicability and can be extended to many biomass-solid waste co-pyrolysis systems, significantly improving the synergistic pyrolysis efficiency and target product selectivity.

[0055] In addition, the present application addresses the problems of non-uniform temperature field and difficulty in monitoring reaction dynamics in the microwave pyrolysis system, and builds an experimental platform that integrates microwave radiation heating, real-time temperature feedback, online mass recording, product condensation separation and data acquisition and analysis. Through the penetration design of the quartz support-electronic balance, non-contact dynamic weighing and synchronous data acquisition of the sample during the reaction are realized, which significantly improves the device structure and data utilization efficiency.

[0056] In summary, the key innovations protected by the present application include the establishment and application of synergistic effect criterion ΔW, the quantitative optimization method of the best ratio of mixed raw materials, and the integrated design of the data acquisition system based on dynamic thermogravimetric monitoring.

[0057] The beneficial effects are: This invention constructs a raw material ratio determination and optimization method based on the synergistic effect criterion ΔW, achieving quantitative identification of the strength of synergistic effects of raw materials under different mixing ratios during microwave synergistic pyrolysis and screening of the optimal ratio. Based on the mass loss curve and combining the theoretical summation with the mass difference in the actual mixing pyrolysis process, this method calculates the synergistic effect parameter ΔW through difference integration. This effectively compensates for the uncertainty caused by relying on single product indicators or empirical judgments in traditional methods, improving the scientific rigor and accuracy of ratio optimization.

[0058] Compared with existing technologies, this method not only significantly improves the selectivity and yield of the target product, but also saves experimental time and energy by reducing unnecessary experiments, resulting in higher experimental efficiency and economy. Furthermore, the formulation optimization framework constructed in this invention has good versatility and scalability, applicable to synergistic pyrolysis systems of various mixed solid wastes and biomass feedstocks. It can provide a rapid and accurate tool for judging the synergistic behavior of complex multi-component systems, significantly enhancing the reliability and controllability of process design.

[0059] Furthermore, this invention proposes a new path for raw material optimization based on coupled analysis of thermogravimetric data and synergistic criteria, which expands the technical boundaries of pyrolysis process research. It has clear innovative orientation and methodological significance, and represents the technological development trend of pyrolysis technology towards data-driven optimization and mechanism quantification.

[0060] In a specific implementation: To verify the effectiveness of the raw material synergy determination and optimization method proposed in this invention, palm kernel shells (PKS) and oily sludge (OS) were selected as representative raw materials. Multiple mass ratio groups were designed, with pure PKS and pure OS groups (PKS / OS = 1:0 and 0:1) serving as control groups, and the remaining mixing ratios (PKS / OS = 3:1, 1:1, and 1:3) serving as co-pyrolysis groups. Mass change curve data for each ratio were collected through thermogravimetric experiments, and synergy criteria were established. The synergistic strength under different ratios was quantitatively evaluated.

[0061] Experimental steps and operating procedures: Sample preparation and proportioning settings Weigh out OS and PKS raw materials separately, mix them evenly according to the preset mass ratio (PKS / OS = 1:0, 0:1, 3:1, 1:1 and 1:3), and label them as PKS, P3O1, P1O1, P1O3 and OS.

[0062] Sample preparation and system preparation The sample was loaded into a quartz crucible and placed in the center of the reaction chamber, supported by a quartz holder to the electronic balance at the bottom of the chamber. After confirming the airtightness, high-purity nitrogen was introduced to achieve inert atmosphere protection during the reaction process, with a nitrogen flow rate of 100 mL / min.

[0063] Heating program settings Start the microwave source and follow the linear power adjustment strategy to heat the sample to 600°C at a rate of about 10°C / min, and maintain the final temperature for 10 minutes. The system automatically records the mass change (mg) and time (s), and the precise temperature is achieved through the temperature feedback control module.

[0064] Condensation and product collection The reaction volatile gas is guided into the series condenser system through the upper gas outlet for condensation and collection, and the liquid phase product remains in the condensation ball, and the gas phase enters the tail gas absorption unit.

[0065] Experimental repeatability control Each proportioning condition is repeated three times to ensure data stability, and the average result is used for subsequent analysis.

[0066] After the experiment is completed, the mass loss curves of pure OS and pure PKS groups are extracted respectively, denoted as and . The above curves reflect the pyrolysis characteristics of each single component under controlled microwave heating and inert atmosphere, including the rate of devolatilization, carbonization residual rate, and pyrolysis rate peak temperature, etc. Then according to the mass weighted average model, the theoretical additive curve ( ) is constructed according to formula (1). (1) Where, and are the mass fractions of oil sludge (OS) and palm kernel shell (PKS) in the mixed system.

[0067] Subsequently, the mixed raw materials were placed in the microwave pyrolysis system according to the set proportion (PKS / OS = 3:1, 1:1 and 1:3), and the real thermogravimetric curve ( ) was recorded, and the difference between the curve and the theoretical additive curve was calculated by formula (2) ) to evaluate whether the system exists to promote or inhibit. The difference is defined as: (2) If <0, it means that the experimental mass loss is faster than the predicted value, and there is a positive synergistic effect; if >0, it is negative synergy or inhibition. To enhance the applicability of the method, The calculation not only covers the whole reaction range, but also can be focused on the main volatile section (such as 250-500 DEG C) for integration to reflect the degree of local synergistic enhancement, and the optimization judgment is more targeted. The experimental results show that when the OS and the PKS ratio is 1:1, The value reaches the maximum negative value, the synergistic effect is the most significant, and the product yield and the reaction rate are the best, which verifies the accuracy and effectiveness of the optimization method.

[0068] The present application realizes scientific determination of raw material ratio and quantitative description of process response by introducing the above-mentioned synergistic criterion and the mass-weighted heat weight prediction model, and provides an efficient and reliable theoretical tool and experimental means for optimization of the synergistic pyrolysis system.

[0069] The above further describes the technical solutions provided by the present application through several specific embodiments, in order to highlight the advantages and benefits of the technical solutions provided by the present application. However, the above several specific embodiments are not used as a limitation on the present application, and any reasonable modification and improvement of the present application, combination and equivalent replacement of the embodiments, etc. based on the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for determining and optimizing the ratio of raw materials in microwave-assisted pyrolysis, characterized in that, The method comprises the following steps: a step of preparing and mixing oily sludge and palm kernel shell according to a preset mass ratio to obtain mixed raw materials; a step of loading the mixed raw materials into a quartz crucible and introducing high-purity nitrogen into a microwave pyrolysis device to establish an inert atmosphere and form a controlled reaction system; a step of applying microwave heating to the controlled reaction system and collecting sample mass change curve and temperature change data; a step of comparing the mass change curve with a theoretical curve formed by weighting and superimposing single raw material pyrolysis curves to obtain a difference result; a step of determining the strength of synergistic effect between raw materials according to the difference result and outputting a synergistic effect determination result; a step of determining an optimal ratio based on the synergistic effect determination result and outputting an optimization conclusion.

2. The method for determining and optimizing the feedstock ratio in microwave-assisted pyrolysis according to claim 1, characterized in that, The oily sludge is derived from a petrochemical wastewater treatment system, dried to control the water content below 5%, and ground to a particle size of less than 100 microns. The palm kernel shell is dried and crushed and sieved to a particle size of less than 200 microns.

3. The method according to claim 1, wherein the ratio of the raw materials is determined and optimized in the microwave-assisted pyrolysis. The frequency of microwave heating is 2450 MHz, the microwave power is adjustable from 0 to 1500 watts, the temperature rise rate is controlled at 10 degrees Celsius per minute, the final temperature is 600 degrees Celsius and is maintained for 10 minutes, and the atmosphere is high-purity nitrogen with a flow rate controlled at 100 to 600 milliliters per minute.

4. The method for determining and optimizing the feedstock ratio in microwave-assisted pyrolysis according to claim 1, characterized in that, The data acquisition system records the sample mass change at intervals of every 10 seconds to form a thermogravimetric curve and a differential thermogravimetric curve, and realizes dynamic monitoring of the reaction process in combination with a temperature feedback module.

5. The method for determining and optimizing the feedstock ratio in microwave-assisted pyrolysis according to claim 1, characterized in that, The difference result is obtained by extracting the pyrolysis curves of pure oily sludge and pure palm kernel shell as controls, calculating a theoretical additive curve according to the mass fraction of each in the mixed system, comparing the theoretical additive curve with the experimental curve of the mixed raw materials, and determining a positive synergistic effect if the experimental curve loses mass faster than the theoretical curve, or determining an inhibitory effect if it loses mass slower than the theoretical curve.

6. The method of claim 1, wherein the method is characterized by, The optimization conclusion is that the strongest positive synergistic effect is obtained when the mass ratio of oily sludge to palm kernel shell is 1:1, which is manifested as an increase in the yield of bio-oil and combustible gas and an optimization of the reaction rate.

7. A device for determining and optimizing the ratio of raw materials in microwave-assisted pyrolysis, characterized in that, The method comprises the following steps: a module of preparing and mixing oily sludge and palm kernel shell according to a preset mass ratio to obtain mixed raw materials; a module of loading the mixed raw materials into a quartz crucible and introducing high-purity nitrogen into a microwave pyrolysis device to establish an inert atmosphere and form a controlled reaction system; a module of applying microwave heating to the controlled reaction system and collecting sample mass change curve and temperature change data; a module of comparing the mass change curve with a theoretical curve formed by weighting and superimposing single raw material pyrolysis curves to obtain a difference result; a module of determining the strength of synergistic effect between raw materials according to the difference result and outputting a synergistic effect determination result; a module of determining an optimal ratio based on the synergistic effect determination result and outputting an optimization conclusion.

8. Computer storage medium for storing a computer program, characterized in that When the computer program is read by a computer, the computer executes the method of claim 1.

9. A computer comprising a processor and a storage medium, characterized in that When the processor reads the computer program stored in the storage medium, the computer executes the method of claim 1.

10. Computer program product as computer program, characterized in that When the computer program is executed, the method of claim 1 is implemented.

Images