A simulated experimental apparatus and method for biochar injection into organic soil reinforcement and carbon sequestration

Abstract

This invention belongs to the field of environmental engineering geology technology, specifically disclosing a simulation experimental device and method for biochar injection into organic soil for reinforcement and carbon sequestration. The experimental device includes a sampling system, an anaerobic / injection control system, a gas monitoring system, a waste liquid collection system, and a data acquisition system. The sampling system includes a soil sample container, a suspension disperser, and a gas overflow device. The anaerobic / injection control system includes a first container, a second container, and a pressure controller. The gas monitoring system is used to detect the type and content of gases generated in the soil sample container. The waste liquid collection system is used to collect wastewater discharged from the soil sample container. The data acquisition system is used to collect data on the injection pressure, gas composition, and injection flow rate of the biochar microparticle suspension. The experimental method involves conducting a simulation experiment using the experimental device. This invention can be used for simulation experimental research on the synergistic treatment of organic-rich soil reinforcement and carbon sequestration through biochar microparticle suspension injection.

Description

Technical Field

[0001] This invention belongs to the field of environmental engineering geology technology, and specifically relates to a biochar injection organic soil reinforcement and carbon fixation simulation experimental device and method. Background Technology

[0002] Organic-rich soils are widely distributed, and their organic matter is highly susceptible to degradation and transformation. On the one hand, degradation produces greenhouse gases such as methane and carbon dioxide; on the other hand, the gases produced during degradation damage the soil structure, and the resulting organic acids corrode the soil's alkaline cementitious materials. This leads to significant engineering geological hazards such as foundation subsidence and landslides, as well as prominent ecological and environmental problems such as greenhouse gas emissions. Improving the stability of organic-rich soils and inhibiting organic matter degradation are key to solving these environmental and engineering geological problems.

[0003] Biochar, as a solidification / stabilization material, shows significant potential for the reinforcement and synergistic carbon sequestration of organic-rich soils. Current treatment methods primarily involve incorporating biochar into the soil. However, this approach leads to direct contact between the organic matter within the soil and air during treatment, resulting in the oxidation and release of greenhouse gases such as CO2. Simultaneously, it damages the original soil structure and weakens its engineering properties. Suspension injection can address this issue; however, currently, there is a lack of suitable instruments and equipment for simulating the synergistic effect of suspension injection in soil reinforcement and carbon sequestration.

[0004] Therefore, there is an urgent need to develop a simulation experimental device and method for injecting biochar microparticle suspensions into organic-rich soil to reinforce carbon fixation. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a biochar injection organic soil reinforcement and carbon fixation simulation experimental device and method.

[0006] The technical solution of the present invention is: a biochar injection organic soil reinforcement and carbon fixation simulation experimental device, including a sampling system, an anaerobic / injection control system, a gas monitoring system, a waste liquid collection system, and a data acquisition system.

[0007] The sampling system includes a soil sample container, a suspension disperser, and a gas overflow device. The top of the soil sample container is fitted with a sealing cap; the suspension disperser is located inside the soil sample container at the bottom; the gas overflow device is located inside the soil sample container at the top. The space between the gas overflow device and the suspension disperser forms a placement cavity for holding the soil sample.

[0008] The anaerobic / injection control system includes a first container, a second container, and a pressure controller. The first container is used to load nitrogen gas and has a first outlet, which is also connected to a gas overflow device to supply nitrogen gas to the soil sample container. The second container is used to load biochar microparticle suspension and has a pressure inlet and a second outlet, which is connected to a suspension disperser to supply biochar microparticle suspension to the soil sample container. The pressure controller has an inlet and an outlet. The inlet is connected to the first outlet via a first gas pipeline, and a first gas valve is installed on the first gas pipeline. The outlet is connected to the pressure inlet via a second gas pipeline to control a constant injection pressure of the biochar microparticle suspension.

[0009] The gas monitoring system is connected to the gas overflow device to detect the type and content of gases generated in the soil sample container.

[0010] The waste liquid collection system is connected to the soil sample container to collect the wastewater discharged from the soil sample container.

[0011] The data acquisition system, connected to the pressure controller and gas monitoring system, is used to collect data on the injection pressure, gas composition, and injection flow rate of the biochar microparticle suspension.

[0012] Furthermore, the inner cavity of the soil sample container is divided into a first cavity, a second cavity, and a third cavity from bottom to top. The suspension disperser is located in the first cavity, the soil sample is located in the second cavity, and the gas overflow device is located in the third cavity.

[0013] Furthermore, the soil sample container has a liquid inlet on the side wall of the first cavity, and a liquid inlet valve is installed on the liquid inlet. The liquid inlet is connected to the second container via a liquid pipeline. The soil sample container has a liquid outlet on the side wall of the third cavity, and a liquid outlet valve is installed on the liquid outlet. The liquid outlet is connected to the collection end of the waste liquid collection system.

[0014] Furthermore, the suspension disperser includes a first tube and a first baffle. An inlet hole is provided on the side wall of the first tube, and the inlet hole corresponds to the position of the inlet interface. The first baffle is located at the upper end of the first tube and has multiple suspension dispersion holes; the soil sample is placed above the first baffle.

[0015] Furthermore, the gas overflow device includes a second tube and a second baffle. A liquid outlet hole is provided on the side wall of the second tube, and the liquid outlet hole corresponds to the position of the liquid outlet interface. The second baffle is located at the lower end of the second tube and placed above the soil sample; the second baffle has multiple gas escape holes.

[0016] Furthermore, the soil sample container is also equipped with a first stirrer, which is located inside the first tube.

[0017] Furthermore, a second stirrer is provided inside the second container.

[0018] A method for simulating biochar injection into organic soil reinforcement and carbon fixation experiments, using the experimental apparatus described above to conduct a biochar microparticle suspension injection into organic soil reinforcement-carbon fixation simulation experiment, specifically including the following steps: Before the experiment, the soil sample is placed in a soil sample bucket; firstly, biochar microparticle suspension is injected into the soil sample in the sampling system through a second container; then, nitrogen gas is injected into the soil sample in the sampling system through a first container, and the gas type and content of the gas generated in the soil sample bucket are detected using a gas monitoring system; subsequently, the soil sample is removed from the soil sample bucket.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention can conduct a simulation experiment study on the synergistic treatment of organic-rich soil reinforcement and carbon sequestration by injecting biochar microparticle suspension. It can simulate the constant pressure injection conditions of calcium-loaded biochar microparticle suspension, restore the on-site anaerobic environment of organic-rich soil, realize real-time monitoring of gas emission characteristics during the anaerobic degradation of organic matter in organic-rich soil, and allow for soil sampling at different times in conjunction with other tests and characterization. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the simulation experimental device in this invention;

[0021] Figure 2 This is a schematic diagram of the suspension disperser in this invention;

[0022] Figure 3 This is a schematic diagram of the gas overflow device in this invention;

[0023] Figure 4 This is a flowchart of the experimental method of the present invention.

[0024] Among them, 1-sampling system, 11-soil sample container, 110-sealing cap, 111-inlet valve, 112-outlet valve, 12-suspension disperser, 121-first tube, 1210-inlet hole, 122-first baffle, 1220-suspension dispersion hole, 13-soil sample, 14-gas overflow device, 141-second tube, 1410-outlet hole, 142-second baffle, 1420-gas escape hole, 15-first stirrer, 2-anaerobic / injection control system, 21-first container, 22-second container, 220-second stirrer, 23-pressure controller, 3-gas monitoring system, 4-waste liquid collection system, 40-flow sensor, 5-data acquisition system, 61-first gas valve, 62-second gas valve, 63-mass flow meter. Detailed Implementation

[0025] The following is combined Figures 1 to 4The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] It should be noted that the circuit connections involved in this invention all adopt conventional circuit connection methods and do not involve any innovation.

[0028] Example

[0029] like Figure 1 The apparatus shown is a biochar injection organic soil reinforcement and carbon fixation simulation experiment device, including a sampling system 1, an anaerobic / injection control system 2, a gas monitoring system 3, a waste liquid collection system 4, and a data acquisition system 5.

[0030] The sampling system 1 includes a soil sample container 11, a suspension disperser 12, and a gas overflow device 14. The top of the soil sample container 11 is provided with a sealing cap 110; the suspension disperser 12 is disposed inside the soil sample container 11 and located at the bottom of the soil sample container 11; the gas overflow device 14 is disposed inside the soil sample container 11 and located at the top of the soil sample container 11. The gas overflow device 14 and the suspension disperser 12 form a placement cavity for placing soil sample 13.

[0031] The anaerobic / injection control system 2 includes a first container 21, a second container 22, and a pressure controller 23. The first container 21 is used to load nitrogen gas and has a first outlet, which is also connected to a gas overflow device 14 for supplying nitrogen gas to the soil sample container 11. The second container 22 is used to load biochar microparticle suspension and has a pressure inlet and a second outlet, which is connected to a suspension disperser 12 for supplying biochar microparticle suspension to the soil sample container 11. The pressure controller 23 has an inlet and an outlet. The inlet is connected to the first outlet via a first gas pipeline, and a first gas valve 61 is installed on the first gas pipeline. The outlet is connected to the pressure inlet via a second gas pipeline for controlling a constant injection pressure of the biochar microparticle suspension. In this embodiment, the first container 21 uses a commercially available nitrogen cylinder. The pressure controller 23 uses a commercially available product of model KTL-AC. Figure 1 As shown, the outlet end of the first container 21 is equipped with a pressure reducing valve. The outlet end of the first container 21 is also connected to the soil sample bucket 11 through a second gas pipeline. The second gas pipeline is equipped with a second gas valve 62 and a mass flow meter 63. The sealing cover 110 is provided with a through hole for the gas pipeline to pass through.

[0032] The gas monitoring system 3 is connected to the gas overflow device 14 and is used to detect the type and content of gas generated in the soil sample container 11. The gas monitoring system 3 adopts a commercially available online gas chromatograph model GC9310-5U, which has an inlet end, and the inlet end is connected to the gas overflow device 14 through a third gas pipeline.

[0033] Waste liquid collection system 4 is connected to soil sample container 11 and is used to collect wastewater discharged from soil sample container 11. Waste liquid collection system 4 uses a waste liquid container, which is connected to soil sample container 11 through a liquid pipeline, and a flow sensor 40 is installed on the liquid pipeline.

[0034] The data acquisition system 5 uses a computer, which is electrically connected to the pressure controller 23, the online gas chromatograph, and the flow sensor 40, respectively, to collect information data, including biochar microparticle suspension injection pressure data, gas composition data, and injection flow rate data.

[0035] Preferably, the inner cavity of the soil sample container 11 is divided into a first cavity, a second cavity, and a third cavity from bottom to top. The suspension disperser 12 is located in the first cavity, the soil sample 13 is located in the second cavity, and the gas overflow device 14 is located in the third cavity.

[0036] Preferably, the soil sample container 11 has a liquid inlet on the side wall of the first cavity, and a liquid inlet valve 111 is provided on the liquid inlet. The liquid inlet is connected to the second container 22 through a liquid pipeline. The soil sample container 11 has a liquid outlet on the side wall of the third cavity, and a liquid outlet valve 112 is provided on the liquid outlet. The liquid outlet is connected to the collection end of the waste liquid collection system 4.

[0037] Preferred, such as Figure 2 As shown, the suspension disperser 12 includes a first tube 121 and a first baffle 122. An inlet hole 1210 is provided on the side wall of the first tube 121, corresponding to the position of the inlet interface. The first baffle 122 is located at the upper end of the first tube 121, and multiple suspension dispersion holes 1220 are formed on the first baffle 122; the soil sample 13 is placed above the first baffle 122.

[0038] Preferred, such as Figure 3 As shown, the gas overflow device 14 includes a second tube 141 and a second baffle 142. A liquid outlet hole 1410 is provided on the side wall of the second tube 141, and the liquid outlet hole 1410 corresponds to the position of the liquid outlet interface. The second baffle 142 is located at the lower end of the second tube 141, placed above the soil sample 13, and has multiple gas escape holes 1420.

[0039] Preferably, the soil sample container 11 is also equipped with a first stirrer 15, which is located inside the first tube 121.

[0040] Preferably, a second stirrer 220 is provided inside the second container 22.

[0041] A method for simulating biochar injection into organic soil reinforcement and carbon sequestration is proposed. This embodiment utilizes the experimental apparatus described to conduct a biochar microparticle suspension injection into organic-rich soil for reinforcement and carbon sequestration simulation experiments. Figure 4 As shown, the specific steps include:

[0042] Before the test, soil sample 13 was placed in soil sample container 11.

[0043] The following steps were performed during the experiment:

[0044] Step 1: Open the nitrogen cylinder, the first gas valve 61, the inlet valve 111, and the outlet valve 112. Close the second gas valve 62. Set the biochar microparticle suspension injection pressure F through the pressure controller 23. Simulate the injection of biochar microparticle suspension into organic soil until the injection time t or the flow sensor 40 test value reaches the expected suspension injection volume Q.

[0045] Step 2: Close the first gas valve 61, the inlet valve 111, and the outlet valve 112, open the second gas valve 62, set the nitrogen inlet flow rate through the mass flow meter 63 to create an anaerobic environment, and at the same time bring the CO2 and CH4 gases generated by the degradation of soil organic matter into the online gas chromatograph for testing and characterization of carbon fixation effect (carbon emission characteristics).

[0046] Step 3: At the set time point, remove the sealing cap 110, close the liquid outlet valve 112, open the liquid inlet valve 111, use the liquid to push out the soil sample 13, and combine it with geotechnical tests to characterize the reinforcement effect.

[0047] The specific models of the above electronic components are not specifically specified; any commercially available ordinary products can be selected, as long as they can meet the usage requirements of this invention.

[0048] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A biochar-injected organic soil reinforcement and carbon fixation simulation experimental device, characterized in that, include: The sampling system (1) includes: a soil sample container (11) with a sealing cap (110) on top; a suspension disperser (12) located inside the soil sample container (11) at the bottom; and a gas overflow device (14) located inside the soil sample container (11) at the top. The gas overflow device (14) and the suspension disperser (12) form a placement cavity for placing soil samples (13). The anaerobic / injection control system (2) includes: a first container (21) for loading nitrogen gas, having a first outlet, the first outlet being connected to a gas overflow device (14) for supplying nitrogen gas to the soil sample container (11); a second container (22) for loading biochar microparticle suspension, having a pressure inlet and a second outlet, the second outlet being connected to a suspension disperser (12) for supplying biochar microparticle suspension to the soil sample container (11); a pressure controller (23) having an inlet end and an outlet end, the inlet end being connected to the first outlet through a first gas pipeline, and a first gas valve (61) being provided on the first gas pipeline; the outlet end being connected to the pressure inlet through a second gas pipeline for controlling a constant biochar microparticle suspension injection pressure; The gas monitoring system (3) is connected to the gas overflow device (14) and is used to detect the type and content of gas generated in the soil sample container (11); Waste liquid collection system (4) is connected to soil sample container (11) and is used to collect wastewater discharged from soil sample container (11); The data acquisition system (5) is connected to the pressure controller (23) and the gas monitoring system (3) to collect data on the injection pressure, gas composition, and injection flow rate of the biochar microparticle suspension.

2. The biochar-injected organic soil reinforcement and carbon fixation simulation experimental device as described in claim 1, characterized in that, The inner cavity of the soil sample container (11) is divided into a first cavity, a second cavity and a third cavity from bottom to top. The suspension disperser (12) is located in the first cavity, the soil sample (13) is located in the second cavity, and the gas overflow device (14) is located in the third cavity.

3. The biochar-injected organic soil reinforcement and carbon fixation simulation experimental device as described in claim 2, characterized in that, The soil sample container (11) is provided with a liquid inlet on the side wall of the first cavity, and a liquid inlet valve (111) is provided on the liquid inlet. The liquid inlet is connected to the second container (22) through a liquid pipeline. The soil sample container (11) has a liquid outlet on the side wall of the third cavity, and a liquid outlet valve (112) is provided on the liquid outlet. The liquid outlet is connected to the collection end of the waste liquid collection system (4).

4. The biochar-injected organic soil reinforcement and carbon fixation simulation experimental device as described in claim 3, characterized in that, The suspension disperser (12) includes: The first tube body (121) has a liquid inlet hole (1210) on its side wall, and the liquid inlet hole (1210) corresponds to the position of the liquid inlet interface; The first baffle (122) is located at the upper end of the first tube (121), and multiple suspension dispersion holes (1220) are opened on the first baffle (122); the soil sample (13) is placed above the first baffle (122).

5. The biochar-injected organic soil reinforcement and carbon fixation simulation experimental device as described in claim 4, characterized in that, The gas overflow device (14) includes: The second tube (141) has a liquid outlet hole (1410) on its side wall, and the liquid outlet hole (1410) corresponds to the position of the liquid outlet interface; The second baffle (142) is located at the lower end of the second tube (141) and placed above the soil sample (13). Multiple gas vent holes (1420) are provided on the second baffle (142).

6. The biochar-injected organic soil reinforcement and carbon fixation simulation experimental device as described in claim 4, characterized in that, The soil sample container (11) is also equipped with a first stirrer (15), which is located inside the first tube (121).

7. The biochar-injected organic soil reinforcement and carbon fixation simulation experimental device as described in claim 1, characterized in that, The second container (22) is equipped with a second stirrer (220).

8. A method for simulating biochar injection into organic soil reinforcement and carbon sequestration experiments, characterized in that, The experiment of injecting biochar microparticle suspension into organic soil to strengthen and fix carbon using the experimental apparatus described in any of claims 1-7 includes the following steps: Before the experiment, the soil sample (13) is placed in the soil sample bucket (11); biochar microparticle suspension is first injected into the soil sample (13) in the sampling system (1) through the second container (22); nitrogen gas is then injected into the soil sample (13) in the sampling system (1) through the first container (21), and the gas type and content of the gas generated in the soil sample bucket (11) are detected by the gas monitoring system (3); then the soil sample (13) is taken out from the soil sample bucket (11).

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