Coal seam storage COmethod for non-mining area of coal mine

Abstract

The invention belongs to the technical field of CO2 sealing and storage, and particularly relates to a method for sealing and storing CO2 in a coal seam of a coal mine non-mining area, which comprises the following steps: S1, sealing and storing CO2 in the coal seam; s2, the ecological carbon sink function of the mining area is improved, soil carbon sink, water body carbon sink and vegetation carbon sink are improved, soil carbon sink improvement comprises total carbon content improvement, organic carbon sink improvement and stable organic carbon sink improvement, and the improvement method is divided into two aspects of a soil treatment technology and a plant treatment technology; s3, preventing and controlling ecological carbon sink loss of the mining area; and S4, mining area whole-process total-factor carbon sink comprehensive management is carried out. By means of vegetation, soil and water body carbon sink main bodies, measures of soil carbon pool sink increasing, vegetation carbon pool sink increasing, surface collapse repairing sink increasing and the like are adopted, CO2 is absorbed and stored in the coal mine area ecological carbon pool, the ecological carbon sink potential of the coal mine area is fully excavated, the soil and vegetation carbon sink reserves are improved, the coal mine area engineering carbon sink capacity is improved, and the coal mine area ecological carbon sink capacity is improved. Therefore, the damage to geology and ecological environment caused by CO2 sealed in the coal seam is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO2 storage, and in particular relates to a method for storing CO2 in a coal seam in an unmineable area of ​​a coal mine. Background Art

[0002] Under the general background of "carbon peak and carbon neutrality", CO2 geological storage technology, as the most effective measure to mitigate CO2 emissions, will become the key to influencing the progress of carbon neutrality. Coalbed CO2 storage refers to injecting captured CO2 into coal seams and isolating it underground for a long time through geological storage to reduce its impact on the atmosphere. Figure 1 As shown, CO2 storage in coal seams mainly includes two major systems: injection and production. After the flue gas is injected into the coal seam, due to the coal's adsorption capacity for gas: CO2>CH4>N2, CH4 and N2 are gradually displaced and desorbed by CO2, and then extracted through production.

[0003] However, storing CO2 in coal seams also involves a variety of safety risks. For example, after CO2 is injected, it is easy to cause geological structure instability, leading to CO2 leakage, acidification of soil and water, damage to the surrounding ecological environment, and affect human health.

[0004] Therefore, in response to the above technical problems, it is necessary to provide a method for storing CO2 in coal seams in unmineable areas of coal mines.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a method for storing CO2 in coal seams in unmineable areas of coal mines, which can solve the problem that storing CO2 in coal seams is prone to damage the geological and ecological environment.

[0007] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0008] A method for storing CO2 in a coal seam in an unmineable area of ​​a coal mine, comprising the following steps:

[0009] S1. CO2 storage in coal seams;

[0010] S2. Improve the ecological carbon sink function of the mining area, including improving soil carbon sink, water carbon sink and vegetation carbon sink. Among them, soil carbon sink improvement includes total carbon content improvement, organic carbon sink improvement and stable organic carbon sink improvement. The improvement methods are divided into two aspects: soil treatment technology and plant treatment technology;

[0011] S3. Prevent and control the loss of ecological carbon sinks in mining areas;

[0012] S4. Comprehensive management of carbon sinks throughout the entire process and in all elements of the mining area.

[0013] In one or more embodiments of the present invention, in S2, the vegetation carbon sink enhancement measures include:

[0014] S201. Select plants with large biomass, and construct a native plant community structure with mixed trees, shrubs and grasses, multiple layers and deep and shallow roots, so as to make full use of the vertical growth space of vegetation to increase the biomass of vegetation per unit area;

[0015] S202. Since the restoration of vegetation in mining areas is largely restricted by soil environmental factors, we should strengthen the management of nutrients, water and growth regulation after the planting of vegetation in Kekegai mining area on the basis of the management of soil structure and nutrient status in mining areas before planting vegetation, so as to ensure the promotion of the growth of both above-ground and underground parts of vegetation in mining areas;

[0016] S203. For plants that can be managed in a straight-cut manner, consider increasing the preservation time of organic carbon in the treated plants to enhance the overall vegetation carbon sink in the mining area;

[0017] S204. Preserve vegetation litter and dead wood in situ to reduce the migration of regional carbon sinks.

[0018] In one or more embodiments of the present invention, in S201, the plants with larger biomass are selected from plants with high phytolith content.

[0019] In one or more embodiments of the present invention, S202 further includes the step of replanting suitable and high-biomass vegetation to improve the growth rate and quality of individual plants in the mining area.

[0020] In one or more embodiments of the present invention, in S203, the method of enhancing the overall vegetation carbon sink in the mining area is one or more combinations of surface carbonization treatment, overall carbonization treatment, and crushing and pressing into charcoal.

[0021] In one or more embodiments of the present invention, the soil carbon sink enhancement measures include: slowing down the mineralization emission of existing inorganic and organic carbon in the mining area soil by controlling the surface disturbance caused by coal mining; achieving a rapid and significant increase in the overall organic carbon sink by further adding organic and inorganic carbon materials; and enhancing the soil organic carbon sink by applying organic materials, and the application of organic materials is an important measure to improve soil structure and sustainably enhance soil fertility.

[0022] In one or more embodiments of the present invention, the organic material is one or more combinations of straw, farmyard manure, organic fertilizer, peat and earthworm castings.

[0023] In one or more embodiments of the present invention, in S3, the specific steps for the loss of soil carbon sink in the mining area are as follows:

[0024] S301. Improve the carbon sink effect of soil improvement in mining areas. On the premise of increasing the application of organic materials, appropriately increase the application of inert and slow-release soil improvement materials, build a good soil aggregate structure and organic-inorganic complex structure, and promote the stability of the mining area soil's own structure, soil nutrients, and soil carbon sink functions;

[0025] S302. In the process of landform reshaping and land leveling in the mining area, water and soil conservation engineering measures such as slope leveling, intercepting drainage ditches, fish scale pits, gullies and silt dams shall be adopted to prevent soil erosion, promote the growth of ecological vegetation, produce good water and soil conservation effects as early as possible, and strengthen the management and maintenance of later water and soil conservation measures to avoid direct carbon sink removal caused by soil erosion and secondary carbon sink loss caused by affecting plant growth;

[0026] S303. Take comprehensive measures to strengthen the prevention and control of spontaneous combustion of residual coal and waste rock piles in mining areas, and avoid carbon emissions from the surface and shallow soil carbon pools caused by spontaneous combustion;

[0027] S304. Carry out soil pollution risk assessment in mining areas in the early stage, and carry out early treatment where necessary, reduce the use of soil conditioners, plant growth regulators and pesticides with pollution risks, and avoid new engineering investment and carbon sink leakage caused by new mining area soil pollution remediation projects in the later stage.

[0028] In one or more embodiments of the present invention, in S3, the specific steps for carbon loss during vegetation construction are as follows:

[0029] S3011. Strengthen the design and construction of vegetation restoration in mining areas. In the design and construction of ecological restoration vegetation in mining areas, efforts should be made to build mixed, composite and near-natural vegetation communities based on native plant resources, so as to increase the amount of vegetation carbon sinks while improving the stability of the vegetation system itself;

[0030] S3012. Strengthen soil improvement and fertilization work in the ecological restoration area of ​​the mining area to ensure the survival and high-quality and efficient growth of planted vegetation with good soil structure, fertility level and water holding and supply capacity;

[0031] S3013. Ensure that seedlings are collected and used nearby in accordance with relevant technical standards for afforestation and greening, provide sufficient suitable seedlings at close range, effectively avoid the adverse effects of long-distance transportation of seedlings and climate differences between the original habitat and the mining area, and improve the efficiency and benefits of ecological carbon sink construction in ecologically fragile areas;

[0032] S3014. Strengthen the risk management of carbon sink loss during the planting process, and adopt mandatory management measures such as not counting carbon sinks of non-native plants and off-season plants to avoid carbon sink losses caused by the risk of unstable ecological vegetation establishment.

[0033] In one or more embodiments of the present invention, in S4, a coal mining area carbon sink monitoring platform is constructed based on satellite remote sensing assisted ground verification technology, and based on the site conditions, vegetation profile, etc. of the coal mining area, a comprehensive evaluation method for coal mining area carbon sinks including mining, hydrology, geology, vegetation, soil and other factors is established to quantitatively evaluate the full-caliber and full-life cycle carbon sink situation of the coal mining area. Based on the full-process and full-element carbon sink management platform of the coal mining area, basic ecological information of the coal mining area such as carbon sink data is browsed, queried, entered and managed in real time, and automatic calculation of carbon reserves and related parameters is realized.

[0034] Compared with the prior art, the method for storing CO2 in coal seams in unmineable areas of coal mines of the present invention utilizes the carbon sinks of vegetation, soil and water bodies, and adopts measures such as soil carbon pool enhancement, vegetation carbon pool enhancement, and surface subsidence repair enhancement to absorb and store CO2 in the ecological carbon pool of the coal mining area, fully tap the ecological carbon sink potential of the coal mining area, increase the soil and vegetation carbon sink reserves, and enhance the engineering carbon sink capacity of the coal mining area, so as to reduce the damage to the geological and ecological environment caused by the storage of CO2 in coal seams. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 This is a schematic diagram of a method for storing CO2 in a coal seam in an unmineable area of ​​a coal mine in one embodiment of the present invention;

[0037] Figure 2 This is a flow chart of a method for storing CO2 in a coal seam in an unmineable area of ​​a coal mine in one embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of improving ecological carbon sinks in coal mining areas in one embodiment of the present invention;

[0039] Figure 4 This is a diagram of a method for improving ecological carbon sinks in coal mining areas in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] like Figure 1 to Figure 2 As shown, a method for storing CO2 in a coal seam in an unmineable area of ​​a coal mine in one embodiment of the present invention comprises the following steps:

[0042] S1. CO2 storage in coal seams;

[0043] S2. Improve the ecological carbon sink function of the mining area;

[0044] S3. Prevent and control the loss of ecological carbon sinks in mining areas;

[0045] S4. Comprehensive management of carbon sinks throughout the entire process and in all elements of the mining area.

[0046] like Figure 3 As shown, in order to avoid the instability of geological structures after CO2 injection, which may lead to CO2 leakage, acidification of soil and water, damage to the surrounding ecological environment, and impact on human health, it is necessary to enhance the ecological carbon sink function of mining areas and prevent and control the loss of ecological carbon sinks in mining areas.

[0047] Among them, the key directions for improving ecological carbon sinks in mining areas include: soil carbon sinks, water carbon sinks and vegetation carbon sinks. From the perspective of carbon components, the improvement of soil carbon sink function in mining areas mainly includes three levels: total carbon content improvement, organic carbon sink improvement and stable organic carbon sink improvement. The improvement methods can be divided into two aspects: soil treatment technology and plant treatment technology.

[0048] In addition, the main measurement subjects of vegetation carbon sinks in mining areas are the above-ground and underground biomass of plants and the amount of surface litter. Therefore, the improvement of the carbon sink function of vegetation in mining areas mainly requires taking a variety of measures to fully tap the biomass potential of vegetation in mining areas and significantly increase the above-ground and underground biomass and surface litter of ecological vegetation in mining areas.

[0049] In addition, reservoirs can accumulate organic matter from within the catchment area and reservoir area, thereby burying carbon, and studies have shown that reservoirs bury carbon at a higher rate than natural lakes.

[0050] Specifically, the vegetation carbon sink enhancement measures include the following steps:

[0051] S201. Select plants with large biomass, such as plants with high phytolith content, and construct a native plant community structure with mixed trees, shrubs and grasses, multiple layers and deep and shallow roots, so as to make full use of the vertical growth space of vegetation to increase the biomass of vegetation per unit area;

[0052] S202. Since the restoration of vegetation in mining areas is largely restricted by soil environmental factors, we should strengthen the management of nutrients, water and growth regulation after the planting of vegetation in Kekegai mining area on the basis of the management of soil structure and nutrient status in mining areas before planting vegetation, so as to ensure the promotion of the growth of the above-ground and underground parts of vegetation in mining areas, and appropriately replant and replant suitable and high-biomass vegetation in the later stage to improve the growth rate and quality of individual vegetation in mining areas;

[0053] S203. For plants that can be managed in a straight line, consider increasing the preservation time of organic carbon in the treated plants to enhance the overall vegetation carbon sink in the mining area (such as surface carbonization, overall carbonization, crushing and pressing into charcoal, etc.);

[0054] S204. Preserve vegetation litter and dead wood in situ to reduce the migration of regional carbon sinks.

[0055] Measures to enhance soil carbon sinks include: slowing down the mineralization emissions of existing inorganic and organic carbon in the soil of mining areas by controlling surface disturbance caused by coal mining; achieving a rapid and significant increase in the overall organic carbon sink by further adding organic and inorganic carbon materials; and enhancing soil organic carbon sinks by applying organic materials (including straw, farmyard manure, organic fertilizer, peat and earthworm castings, etc.). The application of organic materials is an important measure to improve soil structure and sustainably enhance soil fertility.

[0056] like Figure 4 As shown in the figure, the main risk points of soil carbon sink leakage in coal mining areas are the natural mineralization and decomposition of organic carbon in the mining area soil, carbon migration caused by soil erosion, spontaneous combustion of some concentrated stockpiled residual coal and coal gangue, and investment in long-term soil pollution remediation projects. Among them, the specific steps for soil carbon sink loss in mining areas are as follows:

[0057] S301. Improve the carbon sink effect of soil improvement in mining areas. On the premise of increasing the application of organic materials, appropriately increase the application of inert and slow-release soil improvement materials, build a good soil aggregate structure and organic-inorganic complex structure, and promote the stability of the mining area soil's own structure, soil nutrients, and soil carbon sink functions;

[0058] S302. In the process of landform reshaping and land leveling in the mining area, water and soil conservation engineering measures such as slope leveling, intercepting drainage ditches, fish scale pits, gullies and silt dams shall be adopted to prevent soil erosion, promote the growth of ecological vegetation, produce good water and soil conservation effects as early as possible, and strengthen the management and maintenance of later water and soil conservation measures to avoid direct carbon sink removal caused by soil erosion and secondary carbon sink loss caused by affecting plant growth;

[0059] S303. Take comprehensive measures to strengthen the prevention and control of spontaneous combustion of residual coal and waste rock piles in mining areas, and avoid carbon emissions from the surface and shallow soil carbon pools caused by spontaneous combustion;

[0060] S304. Carry out soil pollution risk assessment in mining areas in the early stage, and carry out early treatment where necessary, reduce the use of soil conditioners, plant growth regulators and pesticides with pollution risks, and avoid new engineering investment and carbon sink leakage caused by new mining area soil pollution remediation projects in the later stage.

[0061] In addition, the key strategy for dealing with carbon loss during vegetation construction is to improve the survival rate of regreening plant seedlings and avoid duplication of ecological restoration projects, so as to achieve low carbonization of ecological restoration projects themselves. The specific steps are as follows:

[0062] S3011. Strengthen the design and construction of vegetation restoration in mining areas. In the design and construction of ecological restoration vegetation in mining areas, efforts should be made to build mixed, composite and near-natural vegetation communities based on native plant resources, so as to increase the amount of vegetation carbon sinks while improving the stability of the vegetation system itself;

[0063] S3012. Strengthen soil improvement and fertilization work in the ecological restoration area of ​​the mining area to ensure the survival and high-quality and efficient growth of planted vegetation with good soil structure, fertility level and water holding and supply capacity;

[0064] S3013. Ensure that seedlings are collected and used nearby in accordance with relevant technical standards for afforestation and greening, provide sufficient suitable seedlings at close range, effectively avoid the adverse effects of long-distance transportation of seedlings and climate differences between the original habitat and the mining area, and improve the efficiency and benefits of ecological carbon sink construction in ecologically fragile areas;

[0065] S3014. Strengthen the risk management of carbon sink loss during the planting process, and adopt mandatory management measures such as not counting carbon sinks of non-native plants and off-season plants to avoid carbon sink losses caused by the risk of unstable ecological vegetation establishment.

[0066] In S4, research on ecological ground monitoring technology will be carried out, and monitoring technology and equipment for changes in biomass, plant community species composition, structure and function will be developed. Research on monitoring technology for changes in land ecological types in coal mining areas will be carried out. Based on satellite remote sensing-assisted ground verification technology, dynamic monitoring of land use changes in coal mining areas will be achieved.

[0067] At the same time, with the carbon sink baseline survey as the core, and based on the site conditions and vegetation profile of the coal mining area, a comprehensive evaluation method for coal mining area carbon sinks including mining, hydrology, geology, vegetation, soil and other factors is established to quantitatively evaluate the full-caliber and full-life cycle carbon sink situation in the coal mining area. Based on the coal mining area full-process and full-factor carbon sink management platform, the basic ecological information of the coal mining area, such as carbon sink data, is browsed, queried, entered and managed in real time, and the carbon reserves and related parameters are automatically calculated.

[0068] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0069] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for storing CO2 in coal seams in unmineable areas of coal mines, characterized in that: The following steps are involved: S1. Storage of CO2 in coal seams; S2. Improve the ecological carbon sink function of the mining area, including improving soil carbon sink, water carbon sink and vegetation carbon sink. Among them, soil carbon sink improvement includes total carbon content improvement, organic carbon sink improvement and stable organic carbon sink improvement. The improvement methods are divided into two aspects: soil treatment technology and plant treatment technology; S3. Prevent and control the loss of ecological carbon sinks in mining areas; S4. Comprehensive management of carbon sinks throughout the entire process and in all elements of the mining area.

2. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 1, characterized in that: In S2, the vegetation carbon sink enhancement measures include: S201. Select plants with large biomass, and construct a native plant community structure with mixed trees, shrubs and grasses, multiple layers and deep and shallow roots, so as to make full use of the vertical growth space of vegetation to increase the biomass of vegetation per unit area; S202. On the basis of managing the soil structure and nutrient status of the mining area before planting vegetation, strengthen the management of nutrients, water and growth regulation after planting vegetation in the mining area to ensure the growth promotion of the above-ground and underground parts of the vegetation in the mining area; S203. For plants that can be managed in a straight-cut manner, consider increasing the preservation time of organic carbon in the treated plants to enhance the overall vegetation carbon sink in the mining area; S204. Preserve vegetation litter and dead wood in situ to reduce the migration of regional carbon sinks.

3. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 2, characterized in that: In S201, plants with larger biomass are selected from plants with high phytolith content.

4. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 2, characterized in that: In the S202, it also includes the step of replanting suitable and high-biomass vegetation to improve the growth rate and quality of individual plants in the mining area.

5. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 2, characterized in that: In the S203, the method of enhancing the overall vegetation carbon sink in the mining area is one or more combinations of surface carbonization treatment, overall carbonization treatment and crushing and pressing into charcoal.

6. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 1, characterized in that: The soil carbon sink enhancement measures include: slowing down the mineralization emission of existing inorganic and organic carbon in the mining area soil by controlling the surface disturbance caused by coal mining; achieving a rapid and significant increase in the overall organic carbon sink by further adding organic and inorganic carbon materials; and enhancing the soil organic carbon sink by applying organic materials.

7. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 6, characterized in that: The organic material is one or more combinations of straw, farmyard manure, organic fertilizer, peat and earthworm castings.

8. The method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 1, characterized in that: In S3, the specific steps for the loss of soil carbon sink in the mining area are as follows: S301. Improve the carbon sink effect of soil improvement in mining areas. On the premise of increasing the application of organic materials, increase the application of inert and slow-release soil improvement materials to build a good soil aggregate structure and organic-inorganic complex structure; S302. In the process of landform reshaping and land leveling in the mining area, water and soil conservation engineering measures such as slope leveling, intercepting drainage ditches, fish scale pits, ditch valleys and silt dams shall be adopted, and the management and maintenance of soil and water conservation measures in the later stage shall be strengthened; S303. Take comprehensive measures to strengthen the prevention and control of spontaneous combustion of residual coal and waste rock piles in mining areas, and avoid carbon emissions from the surface and shallow soil carbon pools caused by spontaneous combustion; S304. Carry out soil pollution risk assessment in mining areas in advance to reduce the use of soil conditioners, plant growth regulators and pesticides that have pollution risks.

9. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 1, characterized in that: In S3, the specific steps for carbon loss during vegetation construction are as follows: S3011. Strengthen the design and construction of vegetation restoration in mining areas; S3012. Strengthen soil improvement and fertilization work in the ecological restoration area of ​​the mining area; S3013. Ensure that seedlings are taken and used nearby in accordance with the technical standards for afforestation and greening, and provide sufficient suitable seedlings at close range; S3014. Strengthen the risk management of carbon sink loss during the planting process.

10. A method for storing CO2 in coal seams in unmineable areas of coal mines according to claim 1, characterized in that: In the S4, a coal mining area carbon sink monitoring platform is constructed, and a comprehensive evaluation method for coal mining area carbon sink is established based on the site conditions and vegetation profile of the coal mining area to quantitatively evaluate the full-caliber and full-life cycle carbon sink situation of the coal mining area.

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