Soil remediation simulation method and system based on Aspen Plus

Abstract

The invention relates to the technical field of environmental engineering, and discloses a soil remediation simulation method and system based on Aspen Plus. Petroleum-contaminated soil is added into a tubular furnace, thermal desorption remediation and resource recovery experiments are conducted in the nitrogen atmosphere, and gas-liquid-solid products are collected after reaction; the method comprises the following steps: establishing a simulation model for a PCS thermal desorption repair and resource recovery process by adopting Aspen Plus, inputting experimental parameters into the simulation model for simulation to obtain a group of simulation results, comparing the obtained simulation results with an experiment, and verifying the feasibility of the simulation model; carbon emission and the heat value and heat efficiency of the solid product are predicted according to the simulation model, and absolute return of energy recovery economy and carbon emission of the system is established. Integrated analysis of process parameter optimization and energy recovery economy is achieved, a reliable digital tool is provided for process research, evaluation comprehensiveness is improved, laboratory and industrial application is more effectively connected, and efficient and energy-saving economic development of the repair technology is promoted.

Description

Technical Field

[0001] This invention relates to the field of environmental engineering technology, specifically to a soil remediation simulation method and system based on Aspen Plus. Background Technology

[0002] With the continuous growth of global energy demand, the oil industry has developed rapidly. However, oil spills during transportation, processing, and other human activities have polluted the terrestrial environment, making petroleum-contaminated soil (PCS) a pressing environmental problem. Among PCS remediation technologies, thermal desorption is widely used due to its high efficiency and adaptability. However, traditional thermal desorption technologies typically involve burning the generated organic matter in a secondary combustion chamber, resulting in resource waste and high carbon emissions. Furthermore, the damage to soil structure and high energy consumption during high-temperature thermal desorption also limit its effectiveness. Contaminants recovered during thermal desorption can be collected and recycled for further use, which helps reduce overall operating costs.

[0003] To achieve the dual goals of pollutant degradation and resource recovery, an integrated approach combining thermal desorption remediation and resource recovery technologies is a feasible and cost-effective method for remediating petroleum-contaminated soil (PCS). However, the optimization of process parameters for existing thermal desorption remediation and resource recovery technologies for PCS largely relies on experimental trial and error, lacking systematic and efficient simulation and optimization tools. This results in high costs and long cycles for process parameter optimization, and also makes it impossible to assess the carbon emissions and energy recovery economics of the process. Summary of the Invention

[0004] Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a soil remediation simulation method and system based on Aspen Plus. It features the ability to construct a steady-state simulation model and integrate multi-dimensional analysis modules to achieve integrated analysis of process parameter optimization and energy recovery economics. This not only provides reliable digital tools for process research and improves the comprehensiveness of assessment, but also effectively connects laboratory and industrial applications, promoting efficient, energy-saving, and economic development in remediation technologies.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a soil remediation simulation method based on Aspen Plus, comprising:

[0008] Step 1: Add petroleum-contaminated soil to a tubular furnace and conduct thermal desorption remediation and resource recovery experiments under a nitrogen atmosphere. Collect gas, liquid and solid products after the reaction.

[0009] Step 2: A simulation model of the PCS thermal desorption remediation and resource recovery process was established using Aspen Plus. The experimental parameters were input into the simulation model to obtain a set of simulation results. The simulation results were then compared with the experimental results to verify the feasibility of the simulation model.

[0010] Step 3: Predict carbon emissions and calorific value of solid products based on simulation models. ,hot , Efficiency, and establish an absolute return on the system's energy recovery economy and carbon emissions;

[0011] A soil remediation simulation system based on Aspen Plus, applied to the soil remediation simulation method based on Aspen Plus, includes an experimental module, a model building module, and a prediction and evaluation module;

[0012] The experimental module is used to add petroleum-contaminated soil into a tubular furnace and conduct thermal desorption remediation and resource recovery experiments under a nitrogen atmosphere. After the reaction, gas, liquid and solid products are collected.

[0013] The model building module is used to establish a simulation model of PCS thermal desorption remediation and resource recovery process using Aspen Plus. Experimental parameters are input into the simulation model to perform simulation, and a set of simulation results are obtained. The simulation results are compared with the experiments to verify the feasibility of the simulation model.

[0014] The prediction and evaluation module is used to predict carbon emissions and the calorific value of solid products based on the simulation model. , Efficiency, heat And absolute returns.

[0015] Preferably, the simulation model includes a drying unit and a thermal desorption unit;

[0016] The drying unit includes a Heater module, an RStoic module, and a Sep module;

[0017] The Heater module is used to heat the excess heat recovered from the WET-PCS stream containing free water through the heating system and cooler.

[0018] The RStoic module is used to decompose the WET-PCS feed stream into a conventional component water (H2O) stream and an unconventional component dry contaminated soil (DRY-PCS) stream based on the moisture content measured by industrial analysis by setting the Fortran calculation language embedded in the Calculator module.

[0019] The Sep module is used to separate the decomposed H2O streams;

[0020] The thermal desorption unit includes RCSTR1 module, RCSTR2 module, RStoic module, Sep module, GAS-COOL module, ASH-COOL module, and FLASH2 module.

[0021] Preferably, the carbon emissions include direct carbon emissions and indirect carbon emissions; direct carbon emissions are determined directly by Aspen Plus calculation; the formula for calculating indirect carbon emissions E is:

[0022] E = AD × EF;

[0023] Where AD represents activity data, i.e., the consumption of electrical energy; EF represents the regional electricity carbon emission factor.

[0024] Preferably, the calorific value of the solid product includes the higher heating value (HHV) and the lower heating value (LHC) of the solid product, and the formula for calculating the higher heating value (HHV) of the solid product is as follows:

[0025]

[0026] The formula for calculating the lower heating value (LHV) of a solid product is as follows:

[0027]

[0028] Where, m c1 m c2 m H m0, m s m N , m cl These represent the contents of organic carbon, inorganic carbon, hydrogen, oxygen, sulfur, nitrogen, water, and chlorine in the PCS, respectively.

[0029] 7831, 35932, 2212, 3546, 1187, and 578 represent the calorific value contribution coefficients of organic carbon, hydrogen, sulfur, inorganic carbon, oxygen, and nitrogen, respectively.

[0030] 583 represents the latent heat of vaporization of water under standard conditions; 4.184 represents the conversion factor for converting the calorific value from kilocalories per kilogram to kilojoules per kilogram.

[0031] Preferably, the E x The calculation formula is:

[0032]

[0033] in, Representative Chemistry ; Representing physics The calculation formula is:

[0034]

[0035] Where h represents enthalpy; h0 represents standard enthalpy; s represents entropy; s0 represents standard entropy; T0 represents standard temperature; R represents ideal gas constant; x i Represents the mole fraction of the i-th component in the gas;

[0036] Assuming all products entering and exiting the feed are under reference conditions, physical =0, Chemistry The calculation formula is:

[0037]

[0038]

[0039] Among them, 28200.16 represents the standard chemical formula for sulfur per unit mass. ; 1.0438, 0.1882, 0.2509, 0.7256, 0.3830, and 0.3035 represent constants.

[0040] Preferably, the heat E x，heat The calculation formula is:

[0041]

[0042] Where Q represents the heat flow rate of the heat exchanger; T a This represents the temperature of the heat source.

[0043] Preferably, the The formula for calculating efficiency η is:

[0044]

[0045] Among them, E x，product Representing the total of products E x，input Represents the system input Total .

[0046] Preferably, the formula for calculating the absolute return AREI is:

[0047]

[0048] Where, x op The efficiency of a plant that converts diesel fuel into electricity; x gp Q represents the efficiency of converting natural gas into electricity; OILQ represents the total calorific value of oil products; GAS Q represents the total calorific value of the gaseous products; DRY Q represents the energy consumption of the drying unit; R This represents the energy consumption of the thermal desorption unit;

[0049] x op Q OIL +x gp Q GAS Q represents the ability to generate electrical energy; DRY +Q R This represents the input electrical energy.

[0050] Compared with existing technologies, this invention provides a soil remediation simulation method and system based on Aspen Plus, which has the following beneficial effects:

[0051] 1. This invention establishes a simulation model of PCS thermal desorption remediation and resource recovery process using Aspen Plus, breaking through the limitations of traditional experimental research. It provides a reliable digital tool for mechanism analysis and parameter optimization of resource recovery process, transforming complex thermal desorption reaction into a quantifiable and controllable simulation system, laying the foundation for subsequent systematic research on process parameters, and reducing experimental and time costs in process development.

[0052] 2. This invention predicts carbon emissions and the calorific value of solid products based on simulation models. ,hot , This approach improves efficiency and establishes an absolute return on energy recovery and carbon emissions for the PCS thermal desorption system. It enables a comprehensive analysis of the PCS thermal desorption system from all dimensions, overcoming the limitations of single-indicator evaluation. This extends process analysis from a simple judgment of technical feasibility to a comprehensive consideration of resources, energy, and economy, thus enhancing the comprehensiveness and scientific nature of process evaluation.

[0053] 3. This invention achieves integrated analysis of process parameter optimization and energy recovery economics, significantly enhancing the engineering application value of the PCS thermal desorption process. It realizes the synergistic improvement of resource recovery efficiency and energy utilization efficiency, and can clarify the economic feasibility and environmental impact of different parameter combinations at the process design stage. It provides a quantitative basis for the selection of process schemes, effectively connects laboratory research and industrial application, and ensures that the optimized process not only has advanced technology, but also good economic efficiency and environmental friendliness. It promotes the development of thermal desorption remediation technology for petroleum-contaminated soil towards efficient, energy-saving and economical industrial application. Attached Figure Description

[0054] Figure 1 This is a diagram illustrating the steps of the method of the present invention;

[0055] Figure 2 This is a schematic diagram of the system flow of the present invention;

[0056] Figure 3 Flowchart of thermal desorption remediation and resource recovery process for petroleum-contaminated soil;

[0057] Figure 4 This is a schematic diagram of an experimental setup for thermal desorption remediation and resource recovery of petroleum-contaminated soil. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It is worth noting that this application also relates to prior art. Since prior art is well known to those skilled in the art, it will not be described in detail in this application.

[0059] Please see Figures 1-4 A soil remediation simulation method based on Aspen Plus includes:

[0060] Step 1: Add petroleum-contaminated soil to a tubular furnace and conduct thermal desorption remediation and resource recovery experiments under a nitrogen atmosphere of 0.1 MPa and 400–600 °C. Collect gas, liquid and solid products after the reaction.

[0061] Step 2: A simulation model of the PCS thermal desorption remediation and resource recovery process was established using Aspen Plus. The experimental parameters were input into the simulation model to obtain a set of simulation results. The simulation results were then compared with the experimental results to verify the feasibility of the simulation model.

[0062] Step 3: Predict carbon emissions and calorific value of solid products based on simulation models. ,hot , Efficiency, and establish an absolute return on the system's energy recovery economy and carbon emissions;

[0063] A soil remediation simulation system based on Aspen Plus, applied to the soil remediation simulation method based on Aspen Plus, includes an experimental module, a model building module, and a prediction and evaluation module;

[0064] The experimental module is used to add petroleum-contaminated soil into a tubular furnace and conduct thermal desorption remediation and resource recovery experiments under a nitrogen atmosphere. After the reaction, the gas, liquid and solid products are collected.

[0065] The model building module is used to build a simulation model of PCS thermal desorption remediation and resource recovery process using Aspen Plus. Experimental parameters are input into the simulation model to obtain a set of simulation results. The simulation results are compared with the experiments to verify the feasibility of the simulation model.

[0066] The simulation model includes a drying unit and a thermal desorption unit;

[0067] The drying unit includes a Heater module, an RStoic module, and a Sep module;

[0068] Heater module is used to heat the excess heat recovered from the WET-PCS stream containing free water through the heating system and cooler;

[0069] The RStoic module is used to decompose the WET-PCS feed stream into a conventional component water (H2O) stream and an unconventional component dry contaminated soil (DRY-PCS) stream based on the moisture content measured by industrial analysis, by setting the Fortran calculation language embedded in the Calculator module.

[0070] The Sep module is used to separate the decomposed H2O streams;

[0071] The thermal desorption unit includes RCSTR1 module, RCSTR2 module, RStoic module, Sep module, GAS-COOL module, ASH-COOL module, and FLASH2 module;

[0072] The high-temperature thermal desorption process of PCS includes the removal of bound water and the devolatization, cracking, and carbonization of petroleum hydrocarbons. Due to the complex composition of PCS, several heat treatment modules were specified in the simulation to ensure complete thermal repair of PCS. The PCS processing capacity is 1000 kg / h, and the heat treatment temperature and pressure are set at 400-600℃ and 101.325 kPa, respectively. The RCSTR1 and RCSTR2 modules serve as continuous stirred tank reactors to simulate the kinetic reactions of the devolatization and cracking processes of petroleum in PCS. In the RStoic module, pressure, calorific value, and chemical equations are input, and the changes in the carbon number and calorific value of the petroleum are obtained. Unconventional substances C, H, O, N, and S in PCS decompose into corresponding conventional components (such as H2O, H2, H2S, NH3, CO, CO2, CH4, and other hydrocarbons and representative oil components from the ASPEN database) and unconventional components (char). The high-temperature product stream HOT-GAS from thermal desorption is separated into high-temperature solids and high-temperature gases via a Sep module. The solid product stream HOT-ASH is cooled by the ASH-COOL module, and the recovered heat Q is used to heat the WET-PCS feed stream. The high-temperature gaseous product stream HOT-GAS recovers excess heat and preheats the N2 stream via the GAS-COOL heat exchanger module. After cooling, the high-temperature gaseous product is converted into a gas-liquid mixture, which is separated into a non-condensable gas GAS stream and an oil OIL stream via the FLSAH2 module. The non-condensable gas after oil removal mainly contains light hydrocarbons (C1-C4), H2, CO, CO2, H2S, NH3, etc., which can be directly used for power generation or steam production. If necessary, a portion can be directly recycled as auxiliary fuel for the thermal desorption furnace.

[0073] The composition of PCS is quite complex, requiring appropriate simplification during modeling. In this work, PCS is considered an unconventional mixture of free water, soil inorganic minerals (ASH), and KEROGEN. Carbonaceous soil after thermal desorption is also defined as an unconventional mixture of ASH and Char. Their properties will be determined by industrial and elemental analyses. Enthalpy and density were calculated using HCOALGEN and DCOALIGT, respectively. The physical property method was set using RK-SOAVE. During the PCS thermal desorption remediation process in the 400-600℃ temperature range and under an inert gas atmosphere, the petroleum in PCS mainly undergoes desorption, cracking, and carbonization, resulting in complex products that must be appropriately simplified. The PCS thermal desorption oil and non-condensable gas products are complex mixtures of numerous different hydrocarbons. To simulate the thermal remediation process of petroleum in PCS in Aspen Plus, the oil composition was simulated using a single representative component from a relevant compound group to approximate the key properties of the oil. Performance information of the product oil was collected experimentally, including elemental analysis (C, H, O, N, S) and GC-MS analysis. The formulation is compatible with Aspen Plus, and the product oil consists of representative components, including alkanes, alkenes, monoaromatics, and polyaromatics, with carbon chains ranging from C8 to C33. Non-condensable gaseous products include light hydrocarbons (C1-C4), H2, CO, CO2, H2S, and NH3. The reaction pressure is uniform, the PCS particle temperature distribution is uniform, and the entire process operates in steady state. The soil mineral components in the PCS are set as inert components (ASH) and do not participate in the reaction. At temperatures above 400℃, the total petroleum hydrocarbon (TPH) removal rate is higher than 99%, and it is assumed that all TPH participates in the reaction in this process. Gaseous products are converted into electrical energy based on their calorific value and power generation efficiency; only CO2eq emissions are considered.

[0074] After the simulation model is established in the model building module, the operating parameters, physical property parameters, and reaction parameters of the experiment in the experimental module are first systematically organized and then completely input into the simulation model. After the model convergence is adjusted, the simulation is run according to the experimental gradient temperature conditions, and the simulation results corresponding one-to-one with the experimental gas-liquid-solid products and process indicators are extracted. Subsequently, the consistency of product types, reaction trends, and material conversion logic is verified by qualitative comparison, and the relative errors of TPH removal rate and three-phase product yield are calculated by quantitative comparison. For cases that do not meet the standards, the model parameters are modified in a targeted manner and the simulation is re-verified. Finally, when the qualitative logic matches and the quantitative indicators meet the standards, the model is deemed feasible. This step is the currently publicly available model simulation verification technology solution, which will not be elaborated on here.

[0075] The prediction and assessment module is used to predict carbon emissions, calorific value of solid products, and other parameters based on simulation models. , Efficiency, heat And absolute returns;

[0076] Carbon emissions include direct carbon emissions and indirect carbon emissions; direct carbon emissions are calculated directly using Aspen Plus; the formula for calculating indirect carbon emissions E is:

[0077] E = AD × EF;

[0078] Where AD represents activity data, i.e., the consumption of electrical energy; EF represents the regional electricity carbon emission factor.

[0079] The calorific value of a solid product includes its higher heating value (HHV) and lower heating value (LHC). The formula for calculating the HHV of a solid product is as follows:

[0080]

[0081] The formula for calculating the lower heating value (LHV) of a solid product is as follows:

[0082]

[0083] Where, m c1 m c2 m H m0, m s m N , m cl These represent the contents of organic carbon, inorganic carbon, hydrogen, oxygen, sulfur, nitrogen, water, and chlorine in the PCS, respectively.

[0084] 7831, 35932, 2212, 3546, 1187, and 578 represent the calorific value contribution coefficients of organic carbon, hydrogen, sulfur, inorganic carbon, oxygen, and nitrogen, respectively.

[0085] 583 represents the latent heat of vaporization of water under standard conditions; 4.184 represents the conversion factor for converting the calorific value from kilocalories per kilogram to kilojoules per kilogram.

[0086] E x The calculation formula is:

[0087]

[0088] in, Representative Chemistry ; Representing physics The calculation formula is:

[0089]

[0090] Where h represents enthalpy; h0 represents standard enthalpy; s represents entropy; s0 represents standard entropy; T0 represents standard temperature; R represents ideal gas constant; xi Represents the mole fraction of the i-th component in the gas;

[0091] Assuming all products entering and exiting the feed are under reference conditions, physical =0, Chemistry The calculation formula is:

[0092]

[0093]

[0094] Among them, 28200.16 represents the standard chemical formula for sulfur per unit mass. ; 1.0438, 0.1882, 0.2509, 0.7256, 0.3830, and 0.3035 represent constants.

[0095] hot E x，heat The calculation formula is:

[0096]

[0097] Where Q represents the heat flow rate of the heat exchanger; T a This represents the temperature of the heat source.

[0098] The formula for calculating efficiency η is:

[0099]

[0100] Among them, E x，product Representing the total of products E x，input Represents the system input Total .

[0101] Since the specific value of recovered oil and light hydrocarbon gases cannot be defined, the value is estimated by converting the thermochemical energy of the energy-containing products into useful energy sources such as electricity. It is assumed that once the energy of the oil and gases is obtained from the resource recovery process, it can be converted into other useful forms of energy through an energy plant. Considering the efficiency of the energy plant, obtaining the actual energy return is crucial. In this paper, we use the efficiency of the relevant power plant to calculate the absolute return on energy investment. The formula for calculating the absolute return (AREI) is:

[0102]

[0103] Where, x op The efficiency of a plant that converts diesel fuel into electricity; x gpQ represents the efficiency of converting natural gas into electricity; OIL Q represents the total calorific value of oil products; GAS Q represents the total calorific value of the gaseous products; DRY Q represents the energy consumption of the drying unit; R This represents the energy consumption of the thermal desorption unit;

[0104] x op Q OIL +x gp Q GAS Q represents the ability to generate electrical energy; DRY +Q R Represents the input electrical energy;

[0105] To further illustrate the present invention, the following embodiments provide a detailed description. The flowchart for thermal desorption remediation and resource recovery of petroleum-contaminated soil provided in this embodiment is as follows: Figure 1 As shown in Table 1, the product composition used in this simulation is complex and must be appropriately simplified.

[0106] Table 1. Product components involved in the simulated process

[0107]

[0108] Note: Nos. 1-14 are gaseous products. Nos. 15-45 are oily products. No. 48 is a solid product.

[0109] In this simulation, PCS with an oil content of 10% was used as an unconventional substance, and its properties were determined by industrial and elemental analysis. Enthalpy and density were calculated using HCOALGLEN and DCOALIGT, respectively. The physical property method was set using RK-SOAVE. A thermal desorption remediation and resource recovery simulation with a throughput of 1000 kg / h was conducted under a nitrogen atmosphere of 0.1 MPa and 400–600 °C, with no pressure drop in the three reactors. The elemental and industrial analysis results of the PCS feed composition are shown in Table 2.

[0110] Table 2. Industrial and elemental analysis of dry-basis PCS

[0111]

[0112] Example 1

[0113] In the Aspen process, the temperature of the petroleum contaminated soil feed stream (WET-PCS) is 20℃, the pressure is 0.1 MPa, and the flow rate is 1000 kg / h. The necessary material components for simulation are input from Table 1, and the industrial analysis and elemental analysis results of the petroleum contaminated soil composition from Table 2 are also input.

[0114] Sensitivity analysis was performed, with the temperatures of the three thermal desorption reactors set as independent variables (450℃, 500℃, and 550℃ respectively), and the flow rates of the OIL, GAS, and ASH streams defined as dependent variables. After inputting the data, the simulation was run, and the mass fractions of each substance in each product stream were optimized and exported. The simulation results are shown in Table 3.

[0115] Table 3. Comparison of simulated values ​​and actual experimental values ​​of the examples at different temperatures.

[0116]

[0117] As can be seen from the data in the table, the error between the simulation results and the experimental results of the embodiments of this application can be controlled within 10%, and the product yield change trend with temperature is basically consistent with the actual experimental value. The preferred operating conditions are 0.1MPa and nitrogen atmosphere at 400-600℃. The simulation accuracy is high and can guide the actual experiment.

[0118] Example 2

[0119] In the Aspen process, the settings for the oil-contaminated soil feed stream (WET-PCS) are the same as in Example 1. The temperature of the thermal desorption reactor is set to 450℃. After inputting the data, the simulation is run, optimized, and the energy consumption results of each module, the mass fraction of each substance in each stream, and the carbon emission results of the GAS stream are exported.

[0120] The system carbon emissions were calculated using the carbon emission calculation method described in step three. The system carbon emissions and their distribution are shown in Table 4.

[0121] Table 4 Carbon emissions and distribution of the process system

[0122]

[0123] The data in the table shows that the carbon emissions required to treat a unit mass of petroleum-contaminated soil are 277.56 kg CO2. 2eq / tPCS. Direct carbon emissions account for 49.5%, all from greenhouse gas emissions in non-condensable gases. Indirect carbon emissions account for 50.5%, all from the system's electricity and heat consumption, with the drying unit, thermal desorption unit, and condensation recovery unit accounting for 16.7%, 27.2%, and 6.6%, respectively.

[0124] Based on the effective energy in step three ( The calculation method is used to calculate the system's effective energy distribution, as shown in Table 5.

[0125]

[0126]

[0127] A more practical method for assessing the feasibility of industrial processes is... Analysis. The data in the table shows that when the thermal repair temperature is 450℃, the thermal desorption process... The losses were significant, accounting for as much as 13.78%. This was due to the substantial irreversibility of heat transfer within the high-temperature thermal desorption reactor. The hot solid mixture and hot mixed gas after thermal desorption were used to dry PCS and preheat the thermal desorption atmosphere. After heat exchange, their temperature could reach a relatively low level, effectively reducing the product loss during the condensation process of the thermal desorption products. Losses increased overall Efficiency, making it Losses decreased to 3.37%. Long-chain petroleum hydrocarbons were not completely pyrolyzed at the target repair temperature, and the oil yield remained at a relatively high level. It is 37.97%. And the gas... The efficiency was 26.55. In the solid mixture, the char generated during the high-temperature remediation process was not recovered from the remediated soil, and the solid mixture still contained some heat after drying the feed PCS. (heatexergy) cannot be recycled. The loss was 9.79%. Overall, under resource recovery conditions achieved at the target repair temperature, the total cost of the process system was [missing information]. The efficiency can reach 64.52%. In this example, the comprehensive heat treatment of the PCS can effectively realize the resource utilization of the PCS.

[0128] Example 3

[0129] In the Aspen process, the settings for the oil-contaminated soil feed stream (WET-PCS) are the same as in Example 1. A sensitivity analysis is established, with the thermal desorption reactor temperature set as the independent variable (400–600°C). The energy consumption of each module and the calorific value of each stream are defined as the dependent variables. After inputting the data, the simulation is run, optimized, and the required data is exported.

[0130] The calculation is performed according to the method for calculating the absolute rate of return (AREI) of energy investment in step three.

[0131] Table 6 shows the energy investment return rate of the process system resource recovery at 400-600℃ in Example 3 of the present invention.

[0132]

[0133]

[0134] The data in the table shows that the AREI value decreases with increasing temperature, and is less than 1 when the temperature is above 525℃. This indicates that for a PCS with a contamination concentration (oil content) of 10%, if we consider the same conversion efficiency as a commercial plant, there exists a temperature range where the electricity generated from recoverable energy may be more than the electricity used for the overall remediation process, representing a potential net energy gain. However, considering the complexity of PCS in different regions, especially the significant impact of contamination concentration (oil content) on the AREI value—in other words, the recoverable energy rate varies for PCS with different contamination concentrations—a suitable temperature recovery range needs to be determined through analysis.

[0135] The calculation is performed according to the method for calculating the absolute rate of return on energy investment in step three. Table 7 shows the changes in system effective energy at 400–600°C in Example 3 of this invention.

[0136]

[0137] The data in the table show that the system's effective energy efficiency decreases with increasing temperature, especially in the range of 400–600℃. The efficiency decreased from 67.93% to 55.10%. Under the premise of ensuring PCS repair effectiveness at temperatures >400℃, further increasing the temperature during the resource recovery process will lead to… As damage increases, the overall level of directly recoverable renewable energy oil and gas also decreases with rising temperatures.

[0138] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A soil remediation simulation method based on Aspen Plus, characterized in that, include: Step 1: Add petroleum-contaminated soil to a tubular furnace and conduct thermal desorption remediation and resource recovery experiments under a nitrogen atmosphere. Collect gas, liquid and solid products after the reaction. Step 2: A simulation model of the PCS thermal desorption remediation and resource recovery process was established using Aspen Plus. The experimental parameters were input into the simulation model to obtain a set of simulation results. The simulation results were then compared with the experimental results to verify the feasibility of the simulation model. Step 3: Predict carbon emissions and calorific value of solid products based on simulation models. hot Efficiency, and establish an absolute return on the system's energy recovery economy and carbon emissions.

2. A soil remediation simulation system based on Aspen Plus, applied to the soil remediation simulation method based on Aspen Plus as described in claim 1, characterized in that, It includes an experimental module, a model building module, and a prediction and evaluation module; The experimental module is used to add petroleum-contaminated soil into a tubular furnace and conduct thermal desorption remediation and resource recovery experiments under a nitrogen atmosphere. After the reaction, gas, liquid and solid products are collected. The model building module is used to establish a simulation model of PCS thermal desorption remediation and resource recovery process using Aspen Plus. Experimental parameters are input into the simulation model to perform simulation, and a set of simulation results are obtained. The simulation results are compared with the experiments to verify the feasibility of the simulation model. The prediction and evaluation module is used to predict carbon emissions and the calorific value of solid products based on the simulation model. Efficiency, heat And absolute returns.

3. The soil remediation simulation system based on Aspen Plus according to claim 2, characterized in that, The simulation model includes a drying unit and a thermal desorption unit; The drying unit includes a Heater module, an RStoic module, and a Sep module; The Heater module is used to heat the excess heat recovered from the WET-PCS stream containing free water through the heating system and cooler. The RStoic module is used to decompose the WET-PCS feed stream into a conventional component water (H2O) stream and an unconventional component dry contaminated soil (DRY-PCS) stream based on the moisture content measured by industrial analysis by setting the Fortran calculation language embedded in the Calculator module. The Sep module is used to separate the decomposed H2O streams; The thermal desorption unit includes RCSTR1 module, RCSTR2 module, RStoic module, Sep module, GAS-COOL module, ASH-COOL module, and FLASH2 module.

4. The soil remediation simulation system based on Aspen Plus according to claim 2, characterized in that, The carbon emissions include direct carbon emissions and indirect carbon emissions; direct carbon emissions are calculated directly using Aspen Plus; the formula for calculating indirect carbon emissions E is: E = AD × EF; Where AD represents activity data, i.e., the consumption of electrical energy; EF represents the regional electricity carbon emission factor.

5. A soil remediation simulation system based on Aspen Plus according to claim 2, characterized in that, The calorific value of the solid product includes the higher heating value (HHV) and the lower heating value (LHC) of the solid product. The formula for calculating the higher heating value (HHV) of the solid product is as follows: The formula for calculating the lower heating value (LHV) of a solid product is as follows: Where, m c1 m c2 m H m0, m s m N , m cl These represent the contents of organic carbon, inorganic carbon, hydrogen, oxygen, sulfur, nitrogen, water, and chlorine in the PCS, respectively. 7831, 35932, 2212, 3546, 1187, and 578 represent the calorific value contribution coefficients of organic carbon, hydrogen, sulfur, inorganic carbon, oxygen, and nitrogen, respectively. 583 represents the latent heat of vaporization of water under standard conditions; 4.184 represents the conversion factor for converting the calorific value from kilocalories per kilogram to kilojoules per kilogram.

6. The soil remediation simulation system based on Aspen Plus according to claim 2, characterized in that, The E x The calculation formula is: in, Representative Chemistry Representing physics The calculation formula is: Where h represents enthalpy; h0 represents standard enthalpy; s represents entropy; s0 represents standard entropy; T0 represents standard temperature; R represents ideal gas constant; x i Represents the mole fraction of the i-th component in the gas; Assuming all products entering and exiting the feed are under reference conditions, physical =0, Chemistry The calculation formula is: Among them, 28200.16 represents the standard chemical formula for sulfur per unit mass. 1.0438, 0.1882, 0.2509, 0.7256, 0.3830, and 0.3035 represent constants.

7. A soil remediation simulation system based on Aspen Plus according to claim 6, characterized in that, The heat E x，heat The calculation formula is: Where Q represents the heat flow rate of the heat exchanger; T a This represents the temperature of the heat source.

8. A soil remediation simulation system based on Aspen Plus according to claim 7, characterized in that, The The formula for calculating efficiency η is: Among them, E x，product Representing the total of products E x，input Represents the system input Total 9. A soil remediation simulation system based on Aspen Plus according to claim 8, characterized in that, The formula for calculating the absolute return ARTI is as follows: Where, x op The efficiency of a plant that converts diesel fuel into electricity; x gp Q represents the efficiency of converting natural gas into electricity; OIL Q represents the total calorific value of oil products; GAS Q represents the total calorific value of the gaseous products; DRY Q represents the energy consumption of the drying unit; R This represents the energy consumption of the thermal desorption unit; x op Q OIL +x gp Q GAS Q represents the ability to generate electrical energy; DRY +Q R This represents the input electrical energy.

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