Simulation device and evaluation method for natural hydrogen consumption and migration in middle-shallow soil

Abstract

This invention provides a device and evaluation method for simulating and evaluating the consumption and migration of natural hydrogen in shallow and intermediate soil layers, belonging to the field of natural hydrogen technology. The device includes: a core holder, a pressure tracking pump, a temperature controller, a nuclear magnetic resonance (NMR) magnet, an in-situ soil environmental microbial culture medium, a gas chromatograph, and a hydrogen cylinder. The core holder is used to hold the prepared soil sample; the pressure tracking pump is connected to both ends of the core holder via pipelines; the temperature controller is connected to the core holder; the NMR magnet is placed around the core holder; and the in-situ soil environmental microbial culture medium is connected to the core holder. This invention simulates and analyzes the consumption capacity of different bacterial species combinations for natural hydrogen escaping from the shallow surface. It combines NMR technology to visualize the migration trends and occurrence states of natural hydrogen in the soil, clarifying the migration and consumption trends of different bacterial communities, establishing a shallow surface natural hydrogen analysis and evaluation system, and inferring the state of underground natural hydrogen, providing guidance for natural hydrogen exploration.

Description

Technical Field

[0001] This invention belongs to the field of natural hydrogen technology, specifically relating to a device and evaluation method for simulating and evaluating the consumption and migration of natural hydrogen in shallow and medium-depth soil. Background Technology

[0002] High concentrations of natural hydrogen have been detected in various geological environments globally, with significant variations in its content. Current research primarily focuses on different types of sedimentary reservoirs, such as mudstone, shale, carbonate rocks, and sandstone. It is generally believed that highly chemically reactive natural hydrogen readily reacts with inorganic minerals such as quartz and calcite, as well as formation water. However, the depletion effect of natural hydrogen released into the soil layer has not received much attention in the geological field, resulting in a gap in research on natural hydrogen. Summary of the Invention

[0003] This invention provides a device and evaluation method for simulating and evaluating the consumption and migration of natural hydrogen in shallow and medium-depth soil. The aim is to evaluate the consumption patterns and migration status of natural hydrogen that has escaped into shallow and medium-depth soil less than 1 meter deep through experiments, and to establish an analytical evaluation system for actual underground natural hydrogen based on the concentration of natural hydrogen at the shallow surface, thereby providing guidance for natural hydrogen exploration.

[0004] Firstly, to achieve the above objectives, the technical solution adopted by the present invention is: to provide a device for simulating the consumption and migration of natural hydrogen in shallow and medium soil layers, including: a core holder, a pressure tracking pump, a temperature controller, a nuclear magnetic magnet, an in-situ soil environmental microbial culture medium, a gas chromatograph, and a hydrogen tank, wherein the core holder is used to hold the prepared soil sample.

[0005] The overburden tracking pump is connected to both ends of the core holder via pipeline, and is used to introduce fluorinated liquid into both ends of the core holder to provide confining pressure for the soil sample;

[0006] A temperature controller is connected to the core holder and is used to heat the fluoridated liquid to adjust the temperature of the soil sample;

[0007] The nuclear magnetic magnet is placed around the core holder to provide a uniform magnetic field for nuclear magnetic resonance detection and to acquire the nuclear magnetic signals of hydrogen atoms in the soil sample.

[0008] The in-situ soil environment microbial culture medium is connected to the core holder via a pipeline to simulate the actual environment of the in-situ soil.

[0009] A gas chromatograph is installed on the pipeline between the in-situ soil environmental microbial culture medium and the core holder to detect the gas components escaping from the in-situ soil environmental microbial culture medium.

[0010] The hydrogen tank is connected to the in-situ soil environmental microbial culture medium via a pipeline, and is used to supply hydrogen to the in-situ soil within the in-situ soil environmental microbial culture medium.

[0011] In conjunction with the first aspect, in one feasible manner, sampling valves are respectively provided at both ends of the core holder.

[0012] In conjunction with the first aspect, in one feasible manner, a first shut-off valve is provided on the pipeline between the in-situ soil environmental microbial culture medium and the gas chromatograph.

[0013] In conjunction with the first aspect, in one feasible manner, a first flow meter is provided on the pipeline between the in-situ soil environment microbial culture medium and the hydrogen tank.

[0014] In conjunction with the first aspect, in one feasible manner, the side of the in-situ soil environmental microbial culture medium is provided with a plurality of air outlets along its height direction, and each of the air outlets is connected to the pipeline between the in-situ soil environmental microbial culture medium and the gas chromatograph via a branch pipe.

[0015] Secondly, embodiments of the present invention also provide a method for evaluating the migration of natural hydrogen in soil. Based on the aforementioned simulation device for the consumption and migration of natural hydrogen in shallow and intermediate soil layers, the evaluation method includes:

[0016] Step 1: Perform an airtightness test on the simulation equipment;

[0017] Step 2, Natural Hydrogen Emission Efficiency Test:

[0018] Shallow soil samples were collected from the study area and placed in an in-situ soil environmental microbial culture medium.

[0019] Open the hydrogen tank and introduce hydrogen into the in-situ soil environment microbial culture medium without applying additional pressure, and start timing. When the gas chromatograph detects a change in hydrogen concentration, stop timing and record it as t1. t1 is the time for natural hydrogen to escape through the shallow and medium soil layers.

[0020] Step 3, preparation of soil samples;

[0021] Step four: Load the prepared soil sample into the core holder;

[0022] Step 5: Collect in-situ soil again and put it into the in-situ soil environmental microbial culture medium, and make the environment in the in-situ soil environmental microbial culture medium consistent with the actual environment of the shallow soil in the study area.

[0023] Step 6: Based on the natural hydrogen dissipation time measured in Step 2, load the hydrogen discharged from the hydrogen tank to keep the bottom of the in-situ soil environment microbial culture medium filled with hydrogen.

[0024] Step 7: Open the first shut-off valve between the in-situ soil environmental microbial culture medium and the gas chromatograph and start timing. When the time reaches t1, the gas chromatograph detects the gas components discharged from the in-situ soil environmental microbial culture medium and measures the hydrogen concentration, which is recorded as the measured surface natural hydrogen concentration of the study area.

[0025] Step 8, Natural Hydrogen Concentration Assessment:

[0026] Maintaining the hydrogen loading concentration unchanged in step six, the hydrogen loading concentration is adjusted every t1 time interval, and the gas components are detected using the gas chromatograph until the measured hydrogen concentration is consistent with the measured natural hydrogen concentration on the surface of the study area, which is the natural gas concentration in the shallow soil of the study area.

[0027] Step 9, Assessment of natural hydrogen escape pathways:

[0028] After each adjustment of the hydrogen loading concentration, the discharged gas is introduced into the core holder to perform nuclear magnetic resonance on the soil sample, detect the nuclear magnetic signal, evaluate the migration path of natural hydrogen based on the T1-T2 spectrum template, and evaluate the size of the natural hydrogen migration channel based on the T2 spectrum.

[0029] In conjunction with the second aspect, in one feasible manner, in step three, a cylindrical soil sample adapted to the cavity of the core holder is collected within 1 meter vertically to the ground in the study area as the soil sample.

[0030] The collected soil samples were wrapped with a thin film to preserve the pore structure of the soil samples.

[0031] Thirdly, embodiments of the present invention also provide a method for evaluating the ability of different microorganisms in soil to consume natural hydrogen. Based on the aforementioned method for evaluating the migration of natural hydrogen in soil, the evaluation method includes:

[0032] The first step is to use a determined hydrogen loading concentration;

[0033] The second step is the screening and cultivation of microorganisms:

[0034] The microbial community in the shallow soil of the study area was identified, and microbial species that affect the content of natural hydrogen were screened and cultured.

[0035] Sterile soil from the study area was added to the standard culture medium for incubation.

[0036] Step 3, Microbial loading:

[0037] The cultured single microbial community was mixed with sterile soil from the study area according to its biological characteristics and loaded into an in-situ soil environmental microbial culture medium, while maintaining the environment within the in-situ soil environmental microbial culture medium consistent with the actual environment of the shallow soil in the study area.

[0038] Step 4, hydrogen loading:

[0039] Open the hydrogen tank and load hydrogen according to the hydrogen loading concentration determined in step six;

[0040] Step 5, Gas component detection:

[0041] Open the first shut-off valve, and when the hydrogen dissipation time reaches t1, use a gas chromatograph to detect the concentration of hydrogen discharged from the in-situ soil environmental microbial culture medium;

[0042] Step 6, Natural Gas Escape Path Evaluation:

[0043] The emitted hydrogen gas was subjected to nuclear magnetic resonance detection to obtain nuclear magnetic signals, and the migration path of natural hydrogen gas was evaluated based on the T1-T2 spectral template, and the size of the natural hydrogen gas migration channel was evaluated based on the T2 spectrum.

[0044] Step 7: Adjusting the living conditions for microorganisms:

[0045] Based on the suitable survival conditions of the selected microbial species, the environment of the in-situ soil microbial culture medium is changed. Each adjustment is maintained for at least 3 hours to ensure environmental stability. Each adjustment maintains a single variable and completes steps five and six.

[0046] Step 8: Replace the microbial community from step 3, and complete steps 5 and 6.

[0047] In conjunction with the third aspect, in one feasible manner, the ambient temperature of the in-situ soil environment microbial culture medium is adjusted to 20-30℃, while the pressure and humidity remain constant, to complete steps five and six.

[0048] In conjunction with the third aspect, in one feasible manner, in the third step, based on the actual location of the single microbial community in the shallow soil of the study area, the single microbial community is loaded into the in-situ soil environmental microbial culture medium, and the other locations in the in-situ soil environmental microbial culture medium are filled with sterile soil from the study area.

[0049] The device and evaluation method for simulating the consumption and migration of natural hydrogen in shallow and intermediate soil layers provided by this invention have the following advantages compared with existing technologies: By preserving the original microbial community through in-situ soil sampling or artificially cultivating microbial communities, the environmental conditions such as temperature, humidity, and gas content in shallow and intermediate soil layers are simulated. Different bacterial communities are artificially cultivated to simulate the actual geological environment of the soil. Non-destructive gas detection is performed using gas chromatography. The response characteristics and trends of hydrogen atom nuclear magnetic resonance signals in soil samples are determined based on low-field nuclear magnetic resonance technology. The ability of different bacterial combinations to consume natural hydrogen escaping from the shallow surface is simulated and analyzed. Combined with nuclear magnetic resonance technology, the migration trend and occurrence state of natural hydrogen in the soil are visualized and characterized. The migration and consumption trends of different bacterial communities for natural hydrogen are clarified, and an analytical evaluation system for inferring the underground hydrogen content from the natural hydrogen at the shallow surface is established, providing guidance for natural hydrogen exploration.

[0050] The evaluation method provided by this invention aims to simulate and analyze the consumption capacity of microorganisms in shallow soil (less than 1m) for natural hydrogen. It focuses on the consumption effect of microbial communities in shallow soil on the migration of natural hydrogen, and further studies the differences in the impact of different microorganisms on the migration of natural hydrogen. It also reveals the modification effect of non-anaerobic microorganisms on natural hydrogen during its migration to the surface. To a certain extent, it solves the problem of unclear mechanism of influence of shallow soil environment on surface natural hydrogen concentration. By inferring the underground natural hydrogen content through simulation results, it can support the exploration of natural hydrogen. It is of great significance for the exploration of natural hydrogen and the study of its migration mechanism, and is also of great significance for industry-academia research related to natural hydrogen. Attached Figure Description

[0051] Figure 1 A schematic diagram of the structure of the device for simulating the consumption and migration of natural hydrogen in shallow and intermediate soils provided in an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the structure of the in-situ soil environment microbial culture medium provided in an embodiment of the present invention;

[0053] Explanation of reference numerals in the attached figures:

[0054] 1. Sampling valve; 2. Second flow meter; 3. Core holder; 4. NMR magnet; 5. Temperature controller; 6. Overburden tracking pump; 7. Gas chromatograph; 8. In-situ soil environmental microbial culture medium; 9. Hydrogen tank; 10. First flow meter; 12. Power supply; 13. First shut-off valve; 14. Second shut-off valve; 15. Gas outlet. Detailed Implementation

[0055] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0056] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and accompanying drawings of this invention is for distinguishing different objects and not for describing a specific order.

[0057] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy, or order between these entities or operations.

[0058] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0059] Please refer to section 1 as well. Figure 2 The present invention will now describe the device for simulating the consumption and migration of natural hydrogen in shallow and intermediate soil layers. The device includes: a core holder 3, a pressure tracking pump 6, a temperature controller 5, a nuclear magnetic resonance magnet 4, an in-situ soil environmental microbial culture medium 8, a gas chromatograph 7, and a hydrogen tank 9.

[0060] The core holder 3 is used to hold the prepared soil sample; the core holder 3 has a cavity to accommodate the soil sample; the temperature inside the core holder 3 is regulated by the temperature controller 5, and the pressure is provided by the overburden tracking pump 6, so as to provide the soil sample inside the core holder 3 with an environment consistent with the actual shallow soil environment in the study area, thereby simulating the in-situ soil environment of the study area.

[0061] The overburden pressure tracking pump 6 is connected to both ends of the core holder 3 via pipelines. It is used to introduce fluorinated liquid into both ends of the core holder 3 to provide confining pressure for the soil sample and adjust the pressure inside the core holder 3 to simulate the actual pressure of the in-situ soil. A second shut-off valve 14 is installed between the overburden pressure tracking pump 6 and the core holder 3.

[0062] Temperature controller 5 is connected to core holder 3 and is used to change the temperature of fluorinated liquid to adjust the temperature of soil sample and simulate the actual environmental temperature of in-situ soil.

[0063] The nuclear magnetic magnet 4 is placed around the core holder 3 to provide a uniform magnetic field for nuclear magnetic resonance detection using low-field nuclear magnetic resonance technology, and to obtain the nuclear magnetic signals of hydrogen atoms in the soil sample.

[0064] The in-situ soil environment microbial culture medium 8 is connected to the core holder 3 through a pipeline to simulate the actual environment of the in-situ soil and ensure the in-situ soil environment for microorganisms, including temperature, pressure and humidity.

[0065] The gas chromatograph 7 has a TCD probe, which is installed on the pipeline between the in-situ soil environmental microbial culture medium 8 and the core holder 3, and is used to detect the gas components escaping from the in-situ soil environmental microbial culture medium 8.

[0066] The hydrogen tank 9 is connected to the in-situ soil environmental microbial culture medium 8 via a pipeline, and is used to supply hydrogen to the in-situ soil within the in-situ soil environmental microbial culture medium 8.

[0067] The invention provides a device for simulating the consumption and migration of natural hydrogen in shallow and medium-depth soil. This device preserves the original microbial community through in-situ soil sampling, simulating environmental conditions such as temperature, humidity, and gas content in shallow and medium-depth soil. Different bacterial communities are artificially cultured to simulate the actual geological environment of the soil. Non-destructive gas detection is performed using a gas chromatograph (GC-7). The response characteristics and trends of hydrogen atoms in the soil samples are determined using low-field nuclear magnetic resonance (NMR) technology. The device simulates and analyzes the consumption capacity of different bacterial combinations for natural hydrogen escaping from the shallow surface. Combined with NMR technology, the device visualizes the migration trends and occurrence states of natural hydrogen in the soil, clarifying the migration and consumption trends of different bacterial communities. This establishes an analytical evaluation system for inferring the underground hydrogen content from the natural hydrogen found on the shallow surface, providing guidance for natural hydrogen exploration.

[0068] In some embodiments, sampling valves 1 are provided at both ends of the core holder 3. When a soil sample is loaded or removed, the sampling valves 1 are opened. When nuclear magnetic resonance is not required, the sampling valves 1 are closed so that hydrogen cannot enter the core holder 3. When nuclear magnetic resonance is required to collect the nuclear magnetic information of hydrogen atoms, both sampling valves 1 need to be opened.

[0069] In some embodiments, a first shut-off valve 13 is provided on the pipeline between the in-situ soil environmental microbial culture medium 8 and the gas chromatograph 7.

[0070] In some embodiments, a first flow meter 10 is installed on the pipeline between the in-situ soil environment microbial culture medium 8 and the hydrogen tank 9, which is capable of recording the flow rate of hydrogen. A second flow meter 2 is installed on the pipeline between the hydrogen tank 9 and the core holder 3.

[0071] In some embodiments, the in-situ soil environmental microbial culture medium 8 has multiple air outlets 15 along its height direction on its side, and each air outlet 15 is connected to the pipeline between the in-situ soil environmental microbial culture medium 8 and the gas chromatograph 7 via a branch pipe. The selected in-situ soil environmental microbial culture medium 8 has a height h of 1m and is placed vertically to simulate the actual dispersion state of natural hydrogen. An air outlet 15 is set every 20cm in the vertical direction on the side of the in-situ soil environmental microbial culture medium 8 to detect the change of gas composition at that location and correspond to the migration path of natural hydrogen in the soil at that location.

[0072] Based on the same inventive concept, this invention also provides a method for evaluating the migration of natural hydrogen in soil. Based on the aforementioned simulation device for the consumption and migration of natural hydrogen in shallow and intermediate soil layers, the evaluation method includes:

[0073] Step 1: Perform an airtightness test on the simulation equipment;

[0074] When checking for air tightness, the following should be noted: test for leaks in the joints and valves of the equipment's air circuit to ensure the air tightness of the system; check the sealing effect of the core holder 3 to prevent diffused gas from flowing through the contact surface between the core and the holder.

[0075] Step 2, Natural Hydrogen Emission Efficiency Test:

[0076] Soil samples were collected from the shallow soil layer at a depth of one meter in the study area and placed in an in-situ soil environmental microbial culture medium 8.

[0077] Open the hydrogen tank 9 and introduce hydrogen into the in-situ soil environment microbial culture medium 8 without applying additional pressure, and start timing. When the gas chromatograph 7 detects a change in hydrogen concentration, stop timing and record it as t1. t1 is the time for natural hydrogen to escape through the shallow and medium soil layers.

[0078] Step 3, preparation of soil samples;

[0079] Within 1 meter vertically from the ground in the study area, cylindrical soil samples were collected as soil samples, which were adapted to the three cavities of the core holder; specifically, cylindrical samples with a length of 5 cm and a diameter of 25 mm were collected as soil samples.

[0080] The collected soil samples were wrapped with a thin film to preserve the porous structure of the soil. The film was made of polyvinyl fluoride.

[0081] Step 4: Open sampling valve 1 and load the prepared soil sample into core holder 3.

[0082] Step 5: Collect soil samples from the original site and place them into the original soil environmental microbial culture medium 8 according to the original spatial location. Ensure that the environmental conditions such as temperature, pressure, humidity, and gas content in the original soil environmental microbial culture medium 8 are consistent with the actual environment of the shallow soil in the study area.

[0083] Step six: Based on the natural hydrogen dissipation time measured in step two, load the hydrogen discharged from hydrogen tank 9 to keep the bottom of the in-situ soil environment microbial culture medium 8 full of hydrogen.

[0084] Step 7: Open the first shut-off valve 13 between the in-situ soil environmental microbial culture medium 8 and the gas chromatograph 7 and start timing. When the time reaches t1, the gas chromatograph 7 detects the gas components discharged from the in-situ soil environmental microbial culture medium 8 and measures the hydrogen concentration, which is recorded as the measured surface natural hydrogen concentration of the study area.

[0085] Step 8, Natural Hydrogen Concentration Assessment:

[0086] Maintaining the hydrogen loading concentration unchanged in step six, the hydrogen loading concentration is adjusted every t1 time interval (the hydrogen loading concentration can be adjusted incrementally, or the hydrogen loading concentration can remain unchanged each time), and the gas components are detected using a gas chromatograph 7 until the measured hydrogen concentration is consistent with the measured natural hydrogen concentration on the surface of the study area, which is the natural gas concentration in the shallow soil of the study area.

[0087] Step 9, Assessment of the dominant escape pathways of natural hydrogen:

[0088] After each adjustment of the hydrogen loading concentration, the sampling valve 1 is opened, and the gas discharged by the gas chromatograph 7 is introduced into the core holder 3. The soil sample is subjected to nuclear magnetic resonance by the nuclear magnetic magnet 4, and the nuclear magnetic signal is detected. The migration path of natural hydrogen is evaluated according to the T1-T2 spectrum template, and the migration channel size of natural hydrogen is evaluated according to the T2 spectrum.

[0089] During the evaluation test, power supply 12 needs to be turned on to supply power to the equipment.

[0090] By detecting the changes in gas components using gas chromatograph 7, and visually characterizing the simulated natural hydrogen transport state using low-field nuclear magnetic resonance, the dominant transport pathways of natural hydrogen during the escape process are identified.

[0091] Based on the same inventive concept, this invention also provides a method for evaluating the ability of different microorganisms in soil to consume natural hydrogen. The evaluation method for evaluating the migration of natural hydrogen in soil includes:

[0092] The first step is to use the hydrogen loading concentration determined in the natural hydrogen migration evaluation method.

[0093] The second step is the screening and cultivation of microorganisms:

[0094] The microbial community in the shallow soil of the study area was identified, and microbial species that affect the content of natural hydrogen were screened and cultured.

[0095] The culture was carried out by adding sterile soil from the study area to the conventional culture medium.

[0096] Step 3, Microbial loading:

[0097] The cultured single microbial community was mixed with the sterile soil of the study area according to its biological characteristics and loaded into the in-situ soil environment microbial culture medium 8, and the environment in the in-situ soil environment microbial culture medium 8 was kept consistent with the actual environment of the shallow soil in the study area.

[0098] For example, if the in-situ soil is located in the top 0-30cm of the study area, then sterile soil is filled in the 830-100cm position of the in-situ soil environmental microbial culture medium. The in-situ soil is filled in the 0-30cm position, and the environmental conditions such as temperature, humidity, pressure, pH, and oxygen content of the in-situ soil are maintained to be consistent with those of the actual study area.

[0099] Step 4, hydrogen loading:

[0100] Open hydrogen tank 9 and load hydrogen according to the hydrogen loading concentration determined in step six.

[0101] Step 5, Gas component detection:

[0102] Open the first shut-off valve 13. When the hydrogen dissipation time reaches t1, use a gas chromatograph 7 to detect the concentration of hydrogen discharged from the in-situ soil environmental microbial culture medium 8.

[0103] Step 6, Natural Gas Escape Path Evaluation:

[0104] The emitted hydrogen gas was subjected to nuclear magnetic resonance (NMR) detection to obtain NMR signals. The migration path of natural hydrogen gas was evaluated based on the T1-T2 spectral template, and the size of the natural hydrogen gas migration channel was evaluated based on the T2 spectrum.

[0105] Step 7: Adjusting the living conditions for microorganisms:

[0106] Based on the suitable survival conditions of the selected microbial species, the environment of the in-situ soil microbial culture medium 8 is changed. Each adjustment is maintained for at least 3t1 to ensure environmental stability. Each adjustment maintains a single variable and completes steps five and six.

[0107] For example, adjust the ambient temperature of the in-situ soil microbial culture medium 8 to 20-30℃, keep the pressure and humidity constant, and complete steps five and six.

[0108] Step 8: Replace the microbial community from step 3, and complete steps 5 and 6.

[0109] Compared with the prior art, the present invention has the following beneficial effects:

[0110] (1) By simulating the natural gas release time and environmental conditions in the in-situ soil of the study area, and combining nuclear magnetic resonance technology, the migration trend and occurrence state of natural hydrogen in the soil are visualized and characterized. The migration and consumption trends of different bacterial communities of natural hydrogen are clarified, and an analysis and evaluation system for inferring the underground hydrogen state from the natural hydrogen in the shallow surface is established, which provides guidance for the exploration of natural hydrogen.

[0111] (2) By evaluating the consumption of natural hydrogen, we can obtain the actual effect of different microbial communities on natural hydrogen in situ, and obtain the differences in the influence of different microbial communities on the content of natural hydrogen. This has implications for the study of the variation law of natural hydrogen content on the Earth's surface.

[0112] (3) By controlling the changes in the survival conditions of a single microbial community, the differences in the content of natural hydrogen during the escape process under different environments can be characterized, which is of great significance for the preservation of natural hydrogen during the migration process.

[0113] (4) Based on the evaluation process, it is of research significance to explore the impact mechanism of environmental changes on the natural hydrogen emission process.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for evaluating natural hydrogen migration in soil, using a simulation device for natural hydrogen consumption and migration in shallow soil, characterized in that, The evaluation methods include: Step 1: Perform an airtightness test on the simulation equipment; Step 2, Natural Hydrogen Emission Efficiency Test: Shallow soil samples were collected from the study area and placed in an in-situ soil environment microbial culture medium (8); Open the hydrogen tank (9), and without applying additional pressure, introduce hydrogen into the in-situ soil environment microbial culture medium (8) and start timing. When the gas chromatograph (7) detects a change in hydrogen concentration, stop timing and record it as t1. t1 is the time for natural hydrogen to escape through the shallow and medium soil layers. Step 3, preparation of soil samples; Step 4: The prepared soil sample is loaded into the core holder (3); Step 5: Collect in-situ soil again and put it into the in-situ soil environmental microbial culture medium (8), and make the environment in the in-situ soil environmental microbial culture medium (8) consistent with the actual environment of the shallow soil in the study area; Step six: Based on the natural hydrogen dissipation time measured in step two, the hydrogen discharged from the hydrogen tank (9) is loaded to keep the bottom of the in-situ soil environment microbial culture medium (8) full of hydrogen. Step 7: Open the first shut-off valve (13) between the in-situ soil environmental microbial culture medium (8) and the gas chromatograph (7) and start timing. When the time reaches t1, the gas chromatograph (7) detects the gas components discharged from the in-situ soil environmental microbial culture medium (8) and measures the hydrogen concentration, which is recorded as the measured surface natural hydrogen concentration of the study area. Step 8, Natural Hydrogen Concentration Assessment: Maintain the hydrogen loading concentration in step six unchanged, adjust the hydrogen loading concentration once every t1 time, and use the gas chromatograph (7) to detect the gas components until the measured hydrogen concentration is consistent with the measured natural hydrogen concentration on the surface of the study area, which is the natural hydrogen concentration of the shallow soil in the study area. Step 9, Assessment of natural hydrogen escape pathways: After each adjustment of the hydrogen loading concentration, the discharged gas is introduced into the core holder (3) to perform nuclear magnetic resonance on the soil sample, detect the nuclear magnetic signal, evaluate the migration path of natural hydrogen based on the T1-T2 spectrum template, and evaluate the migration channel size of natural hydrogen based on the T2 spectrum. The device for simulating the consumption and migration of natural hydrogen in shallow and intermediate soil layers includes: Core holder (3), used to hold the prepared soil sample; The overburden tracking pump (6) is connected to both ends of the core holder (3) through a pipeline and is used to introduce fluorinated liquid into both ends of the core holder (3) to provide confining pressure for the soil sample; A temperature controller (5) is connected to the core holder (3) and is used to heat the fluorinated liquid to adjust the temperature of the soil sample. A nuclear magnetic magnet (4) is placed around the core holder (3) to provide a uniform magnetic field for nuclear magnetic resonance detection and to acquire the nuclear magnetic signal of hydrogen atoms in the soil sample; In-situ soil environment microbial culture medium (8) is connected to the core holder (3) through a pipeline to simulate the actual environment of in-situ soil; A gas chromatograph (7), installed on the pipeline between the in-situ soil environmental microbial culture medium (8) and the core holder (3), is used to detect the gaseous components escaping from the in-situ soil environmental microbial culture medium (8); and The hydrogen tank (9) is connected to the in-situ soil environmental microbial culture medium (8) via a pipeline and is used to supply hydrogen to the in-situ soil in the in-situ soil environmental microbial culture medium (8).

2. The method for evaluating natural hydrogen migration in soil according to claim 1, wherein In step three, a cylindrical soil sample was collected from within 1 meter of the ground in the study area, which was adapted to the cavity of the core holder (3), as the soil sample. The collected soil samples were wrapped with a thin film to preserve the pore structure of the soil samples.

3. The method for evaluating natural hydrogen migration in soil according to claim 1, wherein The core holder (3) is equipped with sampling valves (1) at both ends.

4. The method for evaluating the migration of natural hydrogen in soil as described in claim 1, characterized in that, A first shut-off valve (13) is installed on the pipeline between the in-situ soil environment microbial culture medium (8) and the gas chromatograph (7).

5. The method for evaluating the migration of natural hydrogen in soil as described in claim 1, characterized in that, A first flow meter (10) is installed on the pipeline between the in-situ soil environment microbial culture medium (8) and the hydrogen tank (9).

6. The method for evaluating the migration of natural hydrogen in soil as described in claim 1, characterized in that, The in-situ soil environment microbial culture medium (8) has multiple air outlets (15) along its height direction on its side, and each air outlet (15) is connected to the pipeline between the in-situ soil environment microbial culture medium (8) and the gas chromatograph (7) through a branch pipe.

7. A method for evaluating the ability of different microorganisms in soil to consume natural hydrogen, based on the soil natural hydrogen migration evaluation method according to any one of claims 1 to 6, characterized in that, The evaluation methods include: The first step is to use the hydrogen loading concentration determined in step six; The second step is the screening and cultivation of microorganisms: The microbial community in the shallow soil of the study area was identified, and microbial species that affect the content of natural hydrogen were screened and cultured. Sterile soil from the study area was added to the standard culture medium for incubation. Step 3, Microbial loading: The cultured single microbial community was mixed with the sterile soil of the study area according to its biological characteristics and loaded into the in-situ soil environment microbial culture medium (8), and the environment in the in-situ soil environment microbial culture medium (8) was kept consistent with the actual environment of the shallow soil in the study area. Step 4, hydrogen loading: Open the hydrogen tank (9) and load hydrogen according to the hydrogen loading concentration determined in step six; Step 5, Gas component detection: Open the first shut-off valve (13), and when the hydrogen dissipation time reaches t1, use a gas chromatograph (7) to detect the concentration of hydrogen discharged from the in-situ soil environmental microbial culture medium (8); Step 6: Evaluation of natural hydrogen escape pathways: The emitted hydrogen gas was subjected to nuclear magnetic resonance detection to obtain nuclear magnetic signals, and the migration path of natural hydrogen gas was evaluated based on the T1-T2 spectral template, and the size of the natural hydrogen gas migration channel was evaluated based on the T2 spectrum. Step 7: Adjusting the living conditions for microorganisms: According to the suitable survival conditions of the selected microbial species, the environment of the in-situ soil microbial culture medium (8) is changed. Each adjustment is maintained for at least 3t1 to keep the environment stable. Each adjustment maintains a single variable and completes the fifth and sixth steps. Step 8: Replace the microbial community from step 3, and complete steps 5 and 6.

8. The method for evaluating the ability of different microorganisms in soil to consume natural hydrogen as described in claim 7, characterized in that, Adjust the ambient temperature of the in-situ soil environment microbial culture medium (8) to 20-30℃, keep the pressure and humidity constant, and complete the fifth and sixth steps.

9. The method for evaluating the ability of different microorganisms in soil to consume natural hydrogen as described in claim 7, characterized in that, In the third step, based on the actual location of the single microbial community in the shallow soil of the study area, the single microbial community is loaded into the in-situ soil environment microbial culture medium (8), and the other locations in the in-situ soil environment microbial culture medium (8) are filled with sterile soil from the study area.

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