Migration-physical adsorption-chemical carbonization determination device for CO2 in porous multiphase medium soil and quantitative analysis method

Abstract

The invention discloses a device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil and a quantitative analysis method, and the device is characterized in that an electronic balance is arranged in a test box, a base is arranged on the electronic balance, and a porous multiphase medium soil sample is placed on a porous stone in the base; the air pressure sensor is used for collecting air pressure; the humidity controller is used for adjusting air humidity; when the electromagnetic valve is opened, gas in the gas storage tank is injected into the test box through the mass flow meter and the electromagnetic valve; the upper computer is used for collecting measured values of the electronic balance and the mass flow meter and potential difference data of the sample under the set injection current, and is used for quantitative analysis of the CO2 migration-physical adsorption-chemical carbonization process in the porous multiphase medium soil. According to the method, gas fixed quantity and resistivity distribution time-varying data can be synchronously obtained, a CO2 migration path is found out, quantitative separation of physical adsorption and chemical carbonization is realized, and spatial distribution characteristics of the physical adsorption quantity and the chemical carbonization quantity of CO2 are determined.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-carbon geotechnical engineering, and specifically relates to a device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil and a quantitative analysis method. Background Art

[0002] Soil is a porous, multiphase, discontinuous medium, its skeleton formed by soil particles of varying minerals, sizes, and shapes, and its pores filled with water and air. Current techniques for measuring CO2 sequestration in soil primarily rely on chemical analysis methods, such as carbonate titration and thermogravimetric analysis. While these methods can determine the total carbonate content in a sample, they have significant limitations in practical application. They only provide static data and cannot measure the dynamic process of CO2 migration, physical adsorption, and chemical fixation in real time, making it difficult to analyze the migration patterns of CO2 in porous media and the kinetics of carbonization reactions. While the contributions of physical adsorption and chemical carbonization mechanisms to carbonization differ significantly, conventional detection methods cannot quantitatively analyze them. Furthermore, existing methods generally suffer from insufficient spatial resolution, only obtaining an overall average carbon sequestration amount across the sample and failing to characterize the differences in CO2 diffusion pathways or the spatial distribution of CO2 physical adsorption and chemical carbonization. Summary of the Invention

[0003] To address the deficiencies in the prior art, the present invention provides a device and quantitative analysis method for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil, which can simultaneously obtain time-varying data of gas fixation and resistivity distribution, identify the CO2 migration path, achieve quantitative separation of physical adsorption and chemical carbonization, and clarify the spatial distribution characteristics of CO2 physical adsorption and chemical carbonization.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: In the first aspect, a device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil is provided, comprising: a test box, an electronic balance is provided in the test box, a base is provided on the electronic balance, and the porous multiphase medium soil sample is placed on a permeable stone located in the base; an air pressure sensor provided on the test box for collecting the gas pressure in the test box, and a humidity controller for adjusting the gas humidity in the test box; a solenoid valve is opened or closed according to the detection value of the air pressure sensor, and when the solenoid valve is opened, the gas in the gas storage tank is injected into the test box through the mass flowmeter and the solenoid valve; a host computer collects the measurement value of the electronic balance, the measurement value of the mass flowmeter and the potential difference data of the porous multiphase medium soil sample under the set injection current, and uses them to quantitatively analyze the CO2 migration-physical adsorption-chemical carbonization process in the porous multiphase medium soil.

[0005] Furthermore, it also includes an ERT analyzer, which collects potential difference data of porous multiphase medium soil samples under a set injection current and uploads it to a host computer.

[0006] Furthermore, more than one layer of ERT probes are arranged along the height direction of the porous multiphase medium soil sample. The ERT probes in each layer form a set number of electrode pairs. The ERT analyzer injects current through adjacent electrode pairs and collects full-section potential difference data of the porous multiphase medium soil sample.

[0007] Furthermore, it also includes: an exhaust valve provided on the test box for exhausting the gas in the test box.

[0008] Furthermore, filter paper is provided between the porous multiphase medium soil sample and the permeable stone.

[0009] Furthermore, a quantitative analysis of the CO2 migration-physical adsorption-chemical carbonization process in porous multiphase medium soil is carried out, including obtaining the temporal and spatial distribution data of the resistivity of the porous multiphase medium soil sample, the cumulative fixed mass data of the gas and the mass change data of the porous multiphase medium soil sample, which are used to generate a three-dimensional carbonization cloud map to track the carbon fixation process of the porous multiphase medium soil sample, as well as to analyze the influence of environmental humidity on the carbon fixation mechanism and the contribution of seepage to the CO2 fixation amount.

[0010] In the second aspect, a quantitative analysis method for CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil is provided, which is based on the CO2 migration-physical adsorption-chemical carbonization measuring device in porous multiphase medium soil described in the first aspect. The method includes: under set test conditions, according to set data acquisition frequency, collecting the potential difference data, cumulative gas input mass and mass of the porous multiphase medium soil sample under set injection current; preprocessing the potential difference data of the porous multiphase medium soil sample and converting it into resistivity time-space data of the porous multiphase medium soil sample, which is used to generate a three-dimensional carbonization cloud map to track the carbon fixation process of the porous multiphase medium soil sample; based on the cumulative gas input mass and the mass of the porous multiphase medium soil sample, calculating the cumulative fixed mass of CO2 and the cumulative water volatilization mass of the porous multiphase medium soil sample through physical adsorption or chemical carbonization mechanism respectively, which is used to analyze the influence of environmental humidity on the carbon fixation mechanism and the contribution of seepage to the CO2 fixation amount.

[0011] Furthermore, the potential difference data of the porous multiphase medium soil sample are preprocessed and converted into the resistivity space-time data of the porous multiphase medium soil sample, including: using adaptive Kalman filtering to eliminate contact noise and remove abnormal data; implementing time data processing based on TransformW software, automatically arranging the time-varying data under different channels, and combining TempERT software to convert the potential difference data of the porous multiphase medium soil sample into the resistivity space-time data of the porous multiphase medium soil sample.

[0012] Furthermore, the cumulative fixed mass of CO2 by the porous multiphase medium soil sample through physical adsorption is: (1) in, is the time-varying data of the cumulative fixation of CO2 by the porous multiphase soil sample through physical adsorption when no seepage occurs. is the time-varying data of the cumulative fixed amount of N2 by physical adsorption in the porous multiphase soil sample when no seepage occurs, and 1.57 is the molar mass ratio of CO2 to N2; i is the experimental group; The cumulative mass of CO2 fixed by the porous multiphase soil sample through chemical carbonization is: (2) in, is the time-varying data of the cumulative fixation of CO2 by chemical carbonization of porous multiphase soil samples when no seepage occurs; Q i+3 is the time-varying data of the cumulative fixation of CO2 by porous multiphase soil samples when no seepage occurs; The time-varying mass data due to water migration in porous multiphase soil samples are: (3) Among them, H i is the time-varying data of the mass of porous multiphase soil sample due to water migration. A value greater than 0 means that water enters the sample, and a value less than 0 means that the water in the sample evaporates. i0 is the initial mass of the porous multiphase soil sample before the gas fixation test begins; M i is the time-varying data of the mass of porous multiphase soil sample when no seepage occurs.

[0013] Furthermore, the difference analysis of the contribution of physical adsorption and chemical carbonization was performed using the Pearson correlation coefficient method. When the Pearson correlation coefficient r>0.8, it was determined that the two mechanisms had a significant synergistic effect, and when the Pearson correlation coefficient r<-0.8, it was determined that the two mechanisms had a significant antagonistic effect.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: an electronic balance is arranged in the test box, a base is arranged on the electronic balance, and the porous multiphase medium soil sample is placed on the permeable stone located in the base; an air pressure sensor is used to collect the gas pressure in the test box, and a humidity controller is used to adjust the gas humidity in the test box; the solenoid valve is opened or closed according to the detection value of the air pressure sensor, and when the solenoid valve is opened, the gas in the gas storage tank is injected into the test box through the mass flow meter and the solenoid valve; the upper computer collects the measurement value of the electronic balance, the measurement value of the mass flow meter and the potential difference data of the porous multiphase medium soil sample under the set injection current, and uses it to quantitatively analyze the CO2 migration-physical adsorption-chemical carbonization process in the porous multiphase medium soil; through multi-field coupling detection, the time-varying data of the gas fixed amount and the resistivity distribution can be synchronously obtained, the CO2 migration path can be identified, the quantitative separation of physical adsorption and chemical carbonization can be realized, and the spatial distribution characteristics of the CO2 physical adsorption amount and the chemical carbonization amount can be clarified. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of a device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil provided by an embodiment of the present invention; Figure 2 yes Figure 1 Schematic diagram of the arrangement of porous multiphase soil samples, where (a) is the front view and (b) is the top view; In the figure: 1. Porous multiphase medium soil sample; 2. Base; 21. Permeable stone; 22. Filter paper; 3. Electronic balance; 4. ERT probe; 5. ERT analyzer; 6. Host computer; 7. Air pressure sensor; 8. Exhaust valve; 9. Gas storage tank; 10. Mass flow meter; 11. Solenoid valve; 12. Test chamber; 13. Humidity controller. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0017] Example 1 like Figure 1 、 Figure 2As shown, a device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil comprises: a test box 12, an electronic balance 3 is provided in the test box 12, a base 2 is provided on the electronic balance 3, a porous multiphase soil sample 1 is placed on a permeable stone 21 located in the base 2; a pressure sensor 7 is provided on the test box 12 for collecting the gas pressure in the test box 12, and a humidity controller 13 is provided for adjusting the gas humidity in the test box 12; a solenoid valve 11 is opened or closed according to the detection value of the pressure sensor 7, and when the solenoid valve 11 is opened, the gas in the gas storage tank 9 is injected into the gas storage tank 9 through the mass flow meter 10 and the solenoid valve 11. Enter the test box 12; the host computer 6 collects the measurement values ​​of the electronic balance 3, the measurement values ​​of the mass flowmeter 10 and the potential difference data of the porous multiphase medium soil sample 1 under the set injection current, and is used for quantitative analysis of the CO2 migration-physical adsorption-chemical carbonization process in the porous multiphase medium soil, including obtaining the resistivity spatiotemporal distribution data of the porous multiphase medium soil sample, the cumulative fixed mass data of the gas and the mass change data of the porous multiphase medium soil sample, which are used to generate a three-dimensional carbonization cloud map to track the carbon fixation process of the porous multiphase medium soil sample, and to analyze the influence of environmental humidity on the carbon fixation mechanism, as well as the contribution of seepage to the CO2 fixation amount.

[0018] The environmental simulation module, designed to accommodate a porous, multiphase soil sample 1, includes an acrylic test chamber 12, a seepage simulation unit, and a humidity control system. The seepage simulation unit is filled with water through a base 2 to a height of 50% of the permeable stone layer 21 to simulate seepage conditions. A humidity controller 13 adjusts the relative humidity within the test chamber 12 to 70%, 80%, or 90%. The humidity controller 13 uses a PID algorithm to adjust the humidity within the test chamber 12 with an accuracy of ±1%, and maintains humidity stability through a condensate recovery device. An exhaust valve 8 is provided on the test chamber 12 to exhaust gas from the chamber 12.

[0019] The seepage simulation unit includes a permeable stone 21 and filter paper 22. Water is injected through the base 2 to simulate soil seepage. Under anhydrous conditions, the permeable stone 21 is kept dry. Under water conditions, water is injected to 50% of the height of the permeable stone 21.

[0020] The gas control module, used to maintain the set pressure within the environmental simulation module, includes a gas tank 9. This includes a CO2 supply tank for carbon dioxide (CO2), an N2 supply tank for nitrogen (N2), a pressure sensor 7, and a solenoid valve 11. These components maintain a constant pressure within a test chamber 12. Pressure sensor 7 monitors the pressure within the chamber in real time and triggers solenoid valve 11 to introduce gas when the pressure drops by more than 5 kPa. The CO2 and N2 supply tanks are 50L stainless steel tanks connected to the chamber 12 via solenoid valve 11. The gas flow rate is 0.2 to 2 L / min, with a pressure-maintaining accuracy of ±0.1 kPa.

[0021] The data detection module is used to collect data from the porous multiphase medium soil sample and the gas path control module under the set state, including a 64-channel electrical resistance tomography system (ERT analyzer), a high-precision electronic balance 3 and a gas mass flowmeter 10. The ERT analyzer uses 32 stainless steel electrodes in a circular array to inject current and collect potential difference data using an adjacent excitation-measurement mode. The electronic balance 3 records the mass change of the porous multiphase medium soil sample 1 every 5 minutes, and the mass flowmeter 10 obtains the cumulative mass of the introduced gas in real time.

[0022] The ERT analyzer's electrode arrangement is as follows: ERT probes 4 are arranged in one or more layers along the height of a porous, multiphase soil sample 1. Each layer consists of a circular array of stainless steel electrodes, forming a set number of electrode pairs. Current is injected through adjacent electrode pairs, and full-section potential difference data is collected. An ERT analyzer 5 collects potential difference data across the porous, multiphase soil sample 1 under the set injection current and uploads it to a host computer 6.

[0023] The data fusion module is used to quantitatively analyze CO2 migration, physical adsorption, and chemical carbonization in porous multiphase soils based on the data collected by the data detection module. It synchronously integrates the resistivity spatiotemporal distribution data, gas cumulative fixed mass data, and sample mass change data detected by the ERT analyzer through the PC (host computer 6), and generates a three-dimensional carbonization cloud map based on the Matlab algorithm.

[0024] The physical adsorption of CO2 and the precipitation of carbonates will cause the resistivity of the soil to change. At the same time, the fixation of the gas by the soil in a sealed environment will cause the air pressure in the box to drop. It is necessary to continuously introduce gas to keep the air pressure in the box at a specific value. Therefore, the present invention constructs a CO2 migration-physical adsorption-chemical carbonization measurement device in porous multiphase medium soil through modular design, and uses the device to implement a quantitative analysis method of CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil. The device includes four core components: air path control module, data detection module, environmental simulation module, and data fusion module. The structure is as follows: Figure 1 shown.

[0025] The gas control module includes a CO2 / N2 dual-source gas supply tank, a gas pressure sensor, and a solenoid valve. Gas is stored in a 316L stainless steel gas tank. The gas pressure sensor measures the pressure within the chamber and determines whether to turn the gas on and off to maintain a constant pressure. The solenoid valve controls the flow of gas. The data detection module includes a 64-channel ERT analyzer, a high-precision electronic balance, and a gas mass flowmeter. The 64-channel ERT analyzer utilizes an array of stainless steel needle electrodes in an adjacent excitation-measurement mode, injecting current to synchronously acquire the temporal and spatial distribution of the sample resistivity. The high-precision electronic balance tracks sample mass changes in real time. The gas mass flowmeter measures the cumulative gas mass introduced in real time, representing the cumulative fixed mass of the sample. The environmental simulation module includes an acrylic chamber, a seepage simulation unit, and a humidity control system. The chamber provides a sealed environment using a 0.5×0.5×0.5m acrylic chamber. Water is added to the sample base to simulate soil seepage. A humidity controller regulates the relative humidity within the chamber to simulate the actual relative humidity of the soil. Data fusion is achieved through the PC, simultaneously collecting cumulative gas mass flow data, resistivity spatiotemporal distribution data, and sample mass change data, enabling multi-field data coupled analysis. Comparative analysis based on cumulative gas mass flow data clarifies the amount of carbon fixed by physical adsorption and chemical carbonization. Combined with sample mass change data, the migration path of CO2 in porous multiphase soils is tracked, and the progress of CO2 physical adsorption and chemical carbonization reactions is determined based on the sample resistivity spatiotemporal distribution data.

[0026] Example 2 Based on the CO2 migration-physical adsorption-chemical carbonization measuring device in porous multiphase medium soil described in Example 1, this embodiment provides a quantitative analysis method for CO2 migration-physical adsorption-chemical carbonization in porous multiphase medium soil, including: under set experimental conditions, according to set data acquisition frequency, collecting the potential difference data, cumulative gas input mass and mass of the porous multiphase medium soil sample under set injection current; preprocessing the potential difference data of the porous multiphase medium soil sample and converting it into resistivity spatiotemporal data of the porous multiphase medium soil sample, which is used to generate a three-dimensional carbonization cloud map to track the carbon fixation process of the porous multiphase medium soil sample; based on the cumulative gas input mass and the mass of the porous multiphase medium soil sample, calculating the cumulative fixed mass of CO2 and the cumulative water volatilization mass of the porous multiphase medium soil sample through physical adsorption or chemical carbonization mechanism respectively, which is used to analyze the influence of environmental humidity on the carbon fixation mechanism and the contribution of seepage to the CO2 fixation amount.

[0027] This paper demonstrates the quantitative analysis method of CO2 migration, physical adsorption, and chemical carbonization in porous, multiphase soils, using the example of CO2 sequestration in compacted porous slag-modified soil (using porous municipal waste incinerator bottom ash as an example) at standard atmospheric pressure. First, a cylindrical sample is prepared; after sample preparation, a CO2 sequestration experiment is conducted.

[0028] S1. Sample Preparation: Grind silty road clay and pass it through a 5 mm sieve for later use. Porous municipal solid waste incinerator bottom ash and pass it through a 5 mm sieve for later use. Prepare compacted porous slag-modified soil samples using the optimal moisture content and 96% compaction as control conditions (a 1:1 mass ratio of silty clay to municipal solid waste incinerator bottom ash, an optimal moisture content of 15-18%, and a static pressing pressure of 2 MPa). Use static pressing to form cylindrical porous multiphase soil samples measuring 100 mm (Ø) x 50 mm (H). Wrap the samples with PVE sealing film.

[0029] S2. Air tightness verification: Close the exhaust valve 8, fill the test chamber 12 with N2 to a pressure of 200kPa, close the air inlet valve and maintain the pressure for 30 minutes, then observe the pressure drop. When the pressure drop is less than 0.1kPa, it is considered that the air tightness is qualified and you can proceed to the next step. Otherwise, the device should be repaired until the air tightness is qualified.

[0030] S3. Test Condition Control: The ambient temperature was maintained at 20 ± 0.5°C. Permeable stone 21, filter paper 22, and the prepared porous multiphase soil sample 1 were placed sequentially on the base 2. Liquid phase conditions and air humidity were set according to the test group (see Table 1). The anhydrous group maintained the base 2 dry. The water group injected water into the base 2 to 50% of the height of the permeable stone 21 to simulate soil seepage. The relative humidity within the chamber was adjusted using a humidity controller 13 to 70%, 80%, and 90% to simulate winter, spring and autumn, and summer, respectively. Four layers of ERT probes were arranged along the height of the sample. Each layer consisted of a circular array of eight stainless steel electrodes, spaced 45 degrees apart.

[0031] S4. Gas Fixation Test: Open solenoid valve 11 and exhaust valve 8 to introduce test gas for 2 minutes to displace the gas in the chamber. Then close exhaust valve 8. When pressure sensor 7 indicates the chamber pressure has reached atmospheric pressure, solenoid valve 11 closes, and the carbon fixation test begins. As the sample fixes the gas, the chamber pressure will gradually decrease. When the pressure drops by more than 5 kPa, solenoid valve 11 automatically introduces gas to maintain the chamber pressure at atmospheric pressure. Repeat this process. When the chamber pressure remains stable for 1 hour, the sample is considered to have reached carbon fixation equilibrium, and the test is terminated.

[0032] Table 1: CO2 fixation trial group design

[0033] In the gas fixation test, a 64-channel ERT system was used to inject current through adjacent electrode pairs, complete a full-section scan every 5 minutes, and obtain time-varying data of the measured potential difference. i ( i The gas mass flow meter records the cumulative gas mass every 5 minutes and obtains the time-varying data Q of the cumulative fixed gas mass. i Use high-precision electronic balance to achieve mass tracking, and record the time-varying data of sample mass every 5 minutes. i .

[0034] S5. Data post-processing: Adaptive Kalman filtering is used to eliminate electrode contact noise and remove abnormal data in the original data. Time data processing is realized based on TransformW software, which automatically arranges the time-varying data under different channels and combines TempERT software to measure the time-varying data of potential difference. i Converted into resistivity distribution space-time data T i . The resistivity in porous multiphase medium soil samples is mainly affected by the conductive properties of the pore fluid and the pore cementation filling conditions. In this embodiment, the pore fluid is water. Pure water is not conductive, but the substances in the soil are dissolved in water. After the ionization reaction, the pore water will be conductive. Therefore, water migration will cause the soil resistivity to decrease. In addition, the physical adsorption of gas and the precipitation of CaCO3 (bottom ash contains CaO, which dissolves in water to form Ca(OH)2, which reacts with CO2 dissolved in water) formed by the sample's chemical carbonization will fill the pore structure, thereby causing the soil resistivity to increase. However, the resistivity change caused by the physical adsorption of gas is slow, while the precipitation of CaCO3 will cause a sudden increase in resistivity. T1~T3 represent the resistivity data of the sample in a N2 environment when there is no seepage in the soil. The soil resistivity is represented by the initial resistivity at times T1 to T3. Since N2 only undergoes physical adsorption, its resistivity change can represent the effects of physical adsorption (a gentle increase in resistivity) and water migration (a decrease in resistivity). Therefore, the time-varying data from groups T1 to T3 were used to calibrate the resistivity variation caused by gas physical adsorption and water migration, respectively. In groups T4 to T9, in addition to physical adsorption and water migration, CaCO3 precipitation due to chemical carbonization also occurred. Therefore, in groups T4 to T9, resistivity spikes (resistivity spikes exceeding 15% of the baseline and lasting for more than three acquisition cycles) were selected to calibrate the resistivity variation caused by CaCO3 precipitation.

[0035] Q1, Q2, and Q3 represent the time-varying data of the cumulative amount of N2 fixed by the sample when there is no seepage in the soil and the relative humidity of the air is 70%, 80%, and 90%, respectively (unless otherwise specified, the cumulative fixed amount in the following text refers to the fixed gas mass). Since N2 does not chemically react with substances in the sample and physical adsorption is not selective for gases, it can be considered that Q1, Q2, and Q3 reflect the physical adsorption capacity of the sample for CO2 at different humidity levels. Therefore, when there is no seepage in the soil and the relative humidity of the air is 70%, 80%, and 90%, respectively, the time-varying data of the cumulative amount of CO2 fixed by the sample through physical adsorption is calculated according to formula (1), that is, the cumulative mass of CO2 fixed by the porous multiphase medium soil sample through physical adsorption is: (1) in, is the time-varying data of the cumulative fixation of CO2 by the porous multiphase soil sample through physical adsorption when no seepage occurs. is the time-varying data of the cumulative fixed amount of N2 by physical adsorption in the porous multiphase soil sample when no seepage occurs, and 1.57 is the molar mass ratio of CO2 to N2; i For the test group.

[0036] Q4, Q5, and Q6 represent the cumulative fixed mass time-varying data of CO2 by the sample when there is no seepage in the soil and the relative humidity of the air is 70%, 80%, and 90%, respectively. At this time, the cumulative fixed mass time-varying data of CO2 by the sample includes physical adsorption and chemical carbonization. 、 、 It reflects the physical adsorption capacity of the sample for CO2. Therefore, when there is no seepage in the soil and the relative humidity of the air is 70%, 80%, and 90%, the cumulative fixation of CO2 by the sample through chemical carbonization is calculated according to formula (2). That is, the cumulative fixation mass of CO2 by the porous multiphase medium soil sample through chemical carbonization is: (2) in, is the time-varying data of the cumulative fixation of CO2 by chemical carbonization of porous multiphase soil samples when no seepage occurs; Q i+3 It is the time-varying data of the cumulative fixation of CO2 by porous multiphase soil samples when no seepage occurs.

[0037] M1 to M6 represent the mass variation over time of the sample at different humidity levels when no seepage occurs. The mass variation of the sample when no seepage occurs is caused by the sample's fixation of gas and the migration of water between the gaseous environment and the sample. Therefore, the time-varying mass data due to water migration in the sample can be calculated using the following formula: (3) Among them, H i is the time-varying data of the mass of porous multiphase soil sample due to water migration. A value greater than 0 means that water enters the sample, and a value less than 0 means that the water in the sample evaporates. i0 is the initial mass of the porous multiphase soil sample before the gas fixation test begins; M i is the time-varying data of the mass of porous multiphase soil sample when no seepage occurs.

[0038] S6. Analysis of test results: The significance of each group of data obtained through the above operations is shown in Table 2.

[0039] Table 2 The significance of each group of data

[0040] Using a Matlab algorithm, the temporal and spatial resistivity data from the test sessions T1-T9 under different environmental conditions were converted into three-dimensional carbonization cloud maps with a resolution of 5 mm × 5 mm × 5 mm. Based on the range of resistivity changes caused by physical adsorption, chemical carbonization, and water migration, the samples were divided into low-resistance areas (high moisture content), medium-resistance areas (CO2 enrichment, dominated by physical adsorption), and high-resistance areas (intensive CaCO3 precipitation, dominated by chemical carbonization). Finally, the three-dimensional carbonization cloud maps at different time points were selected to invert the CO2 migration path and the spatial distribution characteristics of CaCO3.

[0041] Will and By using the origin software to draw the curve, we can get the change curve of the cumulative fixation of CO2 by physical adsorption or chemical carbonization in porous multiphase soil over time. i ( i Take 1~6) and draw the curve of the change of water volatilization mass over time during the physical adsorption or chemical carbonization process of porous multiphase soil. and Comparative analysis can quantitatively distinguish the contributions of physical adsorption and chemical carbonization to the carbon fixation effect of porous multiphase media. Furthermore, the Pearson correlation coefficient method is used to analyze the difference in the contributions of physical adsorption and chemical carbonization. r represents the Pearson correlation coefficient. When r>0.8, it is determined that the two mechanisms have a significant synergistic effect. When r<-0.8, it is determined that the two mechanisms have a significant antagonistic effect.

[0042] Similarly, comparative analysis of the CO2 fixation curves of Q4, Q5, Q6 with those of Q7, Q8, and Q9 can explore the influence characteristics of soil seepage on the carbon sequestration performance of porous multiphase soil; the carbon sequestration curves and water volatilization curves of each group of experiments are combined with the three-dimensional carbonization cloud maps at different time nodes to verify each other, track the soil carbon sequestration reaction process, and identify the influence mechanism of CO2 migration path and changes in environmental factors on the carbon sequestration reaction process of porous multiphase soil.

[0043] This method integrates multi-field coupled detection to simultaneously acquire the cumulative gas fixed mass, the temporal and spatial distribution of resistivity, and the change in sample mass in real time. Quantitative analysis methods are used to analyze the contributions of physical adsorption and chemical carbonization, revealing the mechanisms that influence gas-phase diffusion and liquid-phase permeation migration pathways, as well as changes in ambient pressure and humidity, on CO2 fixation.

[0044] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil, characterized in that: include: A test box (12), wherein an electronic balance (3) is provided in the test box (12), a base (2) is provided on the electronic balance (3), and a porous multiphase medium soil sample (1) is placed on a permeable stone (21) located in the base (2); A pressure sensor (7) provided on the test box (12) for collecting the gas pressure in the test box (12) and a humidity controller (13) for adjusting the gas humidity in the test box (12); The solenoid valve (11) is opened or closed according to the detection value of the air pressure sensor (7). When the solenoid valve (11) is opened, the gas in the gas storage tank (9) is injected into the test box (12) through the mass flow meter (10) and the solenoid valve (11); The host computer (6) collects the measurement values ​​of the electronic balance (3), the measurement values ​​of the mass flow meter (10) and the potential difference data of the porous multiphase medium soil sample (1) under the set injection current, and uses them to quantitatively analyze the CO2 migration-physical adsorption-chemical carbonization process in the porous multiphase medium soil.

2. The device for measuring CO2 migration, physical adsorption and chemical carbonization in porous multiphase soil according to claim 1, characterized in that: The apparatus also includes an ERT analyzer (5), which collects potential difference data of the porous multiphase medium soil sample (1) under a set injection current and uploads the data to a host computer (6).

3. The device for measuring CO2 migration, physical adsorption and chemical carbonization in porous multiphase soil according to claim 2, characterized in that: More than one layer of ERT probes (4) are arranged along the height direction of the porous multiphase medium soil sample (1), and the ERT probes (4) of each layer form a set number of electrode pairs. The ERT analyzer (5) injects current through adjacent electrode pairs and collects full-section potential difference data of the porous multiphase medium soil sample (1).

4. The device for measuring CO2 migration, physical adsorption and chemical carbonization in porous multiphase soil according to claim 1, characterized in that: Also includes: An exhaust valve (8) is provided on the test box (12) and is used to exhaust the gas in the test box (12).

5. The device for measuring CO2 migration, physical adsorption and chemical carbonization in porous multiphase soil according to claim 1, characterized in that: A filter paper (22) is provided between the porous multiphase medium soil sample (1) and the permeable stone (21).

6. The device for measuring CO2 migration, physical adsorption and chemical carbonization in porous multiphase soil according to claim 1, characterized in that: Quantitative analysis of the CO2 migration-physical adsorption-chemical carbonization process in porous multiphase medium soil, including obtaining the temporal and spatial distribution data of resistivity of porous multiphase medium soil samples, the cumulative fixed mass data of gas and the mass change data of porous multiphase medium soil samples, which are used to generate three-dimensional carbonization cloud maps to track the carbon fixation process of porous multiphase medium soil samples, and to analyze the influence of environmental humidity on the carbon fixation mechanism, as well as the contribution of seepage to the CO2 fixation amount.

7. A quantitative analysis method for CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil, characterized by: Based on the device for measuring CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil according to any one of claims 1 to 6, the method comprises: Under the set test conditions and at the set data collection frequency, collect the potential difference data, the cumulative gas injection mass and the mass of the porous multiphase medium soil sample under the set injection current; The potential difference data of the porous multiphase medium soil sample is preprocessed and converted into the resistivity spatiotemporal data of the porous multiphase medium soil sample, which is used to generate a three-dimensional carbonization cloud map to track the carbon fixation process of the porous multiphase medium soil sample; Based on the cumulative mass of gas introduced and the mass of the porous multiphase medium soil sample, the cumulative mass of CO2 fixed and the cumulative mass of water volatilized by the porous multiphase medium soil sample through physical adsorption or chemical carbonization mechanism are calculated, which is used to analyze the influence of environmental humidity on the carbon fixation mechanism and the contribution of seepage to the CO2 fixation.

8. The method for quantitative analysis of CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil according to claim 7, characterized in that: The potential difference data of porous multiphase soil samples are preprocessed and converted into the resistivity spatiotemporal data of porous multiphase soil samples, including: Adaptive Kalman filtering is used to eliminate contact noise and remove abnormal data. Time data processing is implemented based on TransformW software, and the time-varying data under different channels are automatically arranged. Combined with TempERT software, the potential difference data of porous multiphase medium soil samples are converted into resistivity spatiotemporal data of porous multiphase medium soil samples.

9. The quantitative analysis method of CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil according to claim 7, characterized in that: The cumulative fixed mass of CO2 by the porous multiphase soil sample through physical adsorption is: （1） in, is the time-varying data of the cumulative fixation of CO2 by the porous multiphase soil sample through physical adsorption when no seepage occurs. is the time-varying data of the cumulative fixed amount of N2 by physical adsorption in the porous multiphase soil sample when no seepage occurs, and 1.57 is the molar mass ratio of CO2 to N2; i is the experimental group; The cumulative mass of CO2 fixed by the porous multiphase soil sample through chemical carbonization is: （2） in, is the time-varying data of the cumulative fixation of CO2 by chemical carbonization of porous multiphase soil samples when no seepage occurs; Q i+3 is the time-varying data of the cumulative fixation of CO2 by porous multiphase soil samples when no seepage occurs; The time-varying mass data due to water migration in porous multiphase soil samples are: （3） Among them, H i is the time-varying data of the mass of porous multiphase soil sample due to water migration. A value greater than 0 means that water enters the sample, and a value less than 0 means that the water in the sample evaporates. i0 is the initial mass of the porous multiphase soil sample before the gas fixation test begins; M i is the time-varying data of the mass of porous multiphase soil sample when no seepage occurs.

10. The quantitative analysis method of CO2 migration-physical adsorption-chemical carbonization in porous multiphase soil according to claim 7, characterized in that: The difference analysis of the contribution of physical adsorption and chemical carbonization was performed using the Pearson correlation coefficient method. When the Pearson correlation coefficient r>0.8, the two mechanisms were judged to have a significant synergistic effect; when the Pearson correlation coefficient r<-0.8, the two mechanisms were judged to have a significant antagonistic effect.

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