Oil-rich coal in-situ pyrolysis tar filtering and lightening integrated device and method

Abstract

The invention relates to an oil-rich coal in-situ pyrolysis tar filtering and lightening integrated device and method, the device comprises a steel pipe body buried in a rock stratum, and the steel pipe body comprises an inner pipe body and an outer pipe body; a filtering structure is arranged at the bottom of an inner cavity of the inner pipe body and comprises multiple layers of coarse screens and a filtering medium which are arranged from bottom to top; a catalytic conversion structure is arranged above the filtering structure, the catalytic conversion structure comprises a catalytic tube and a catalytic layer, and the interior of the catalytic tube is of a honeycomb structure; a tar mixed steam and additive mixing cavity is formed between the filtering structure and the catalytic conversion structure; the outer pipe body comprises a heating layer, a compression-resistant layer and a heat preservation layer, and the heating layer is tightly attached to the surface of the inner pipe body. The compression-resistant layer is arranged between the steel pipe body and the heating layer; the heat preservation layer is tightly attached to the surface of the steel pipe body. The in-situ pyrolysis tar of the oil-rich coal can be effectively filtered and lightened, the quality of the tar can be regulated and controlled in real time, and the stability and high efficiency of the whole catalytic process are ensured.

Description

Technical Field

[0001] This invention belongs to the field of in-situ pyrolysis technology of oil-rich coal, and particularly relates to an integrated device and method for in-situ pyrolysis tar filtration and lightening of oil-rich coal. Background Technology

[0002] Oil-rich coal is a coal resource that integrates coal, oil, and gas properties. Its pyrolysis development can not only convert coal resources into oil and gas resources, but also convert high-carbon resources into low-carbon resources. The utilization methods of oil-rich coal are mainly divided into two types: surface pyrolysis and underground in-situ pyrolysis. Among them, underground in-situ pyrolysis has the advantage of "hydrogen extraction and carbon fixation." In-situ pyrolysis is a typical method for developing artificial oil and gas reservoirs. It refers to establishing heat introduction and product output channels in the coal seam, and the in-situ heating method causes the coal to pyrolyze, producing liquid (tar, water) and gaseous (pyrolysis gas) hydrocarbons, while leaving the semi-coke underground. Notably, the Shaanxi Coal Geology Group extracted the world's first barrel of in-situ pyrolysis tar in the Dabaodang coalfield in Yulin City, achieving a breakthrough from "0" to "1" in underground raw coal oil extraction. However, the liquid products of in-situ pyrolysis have a complex composition, characterized by a mixture of water, tar, and coal powder, and the tar produced by in-situ pyrolysis is relatively heavy, increasing the complexity of its industrial utilization. Therefore, improving the quality of in-situ pyrolysis tar and realizing the underground light coal tar is of paramount importance in the development of oil-rich coal pyrolysis. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an integrated device and method for filtering and lightening tar from in-situ pyrolysis of oil-rich coal. This technology integrates tar mixture filtration and catalysis, filtering coal particles from tar and water vapor during the upward transport process through the oil extraction pipeline, and gradually carrying out tar catalytic cracking. This overcomes the limitation of the generally low quality of tar produced from in-situ pyrolysis of oil-rich coal, and achieves the lightening of coal tar during underground transportation. Simultaneously, the device can be equipped with H2O and CO2 additives at any time to ensure real-time control of the properties of the coal tar.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: An integrated device for in-situ pyrolysis tar filtration and lightening of oil-rich coal, the device comprising a steel pipe body buried in rock strata, the steel pipe body comprising an inner pipe body and an outer pipe body; The inner cavity of the inner tube is provided with a filter structure, which includes multiple layers of coarse screens arranged from bottom to top and a filter medium filled with quartz beads. A catalytic conversion structure is provided above the filtration structure. The catalytic conversion structure includes a catalytic tube and a catalytic layer. The interior of the catalytic tube has a honeycomb structure, and the catalytic layer is installed on the tube wall of the honeycomb structure. A tar-vapor mixture and additive mixing chamber is formed between the filtration structure and the catalytic conversion structure, and a gas one-way valve is provided in the tar-vapor mixture and additive mixing chamber. The outer tube body includes a heating layer, a pressure-resistant layer, and a heat insulation layer. The heating layer is tightly attached to the surface of the inner tube body to maintain the required temperature stability and prevent tar vapor condensation. The pressure-resistant layer is disposed between the steel tube body and the heating layer, and together with the steel tube body, it enhances the structural strength of the pipeline and ensures safe operation. The heat insulation layer is tightly attached to the surface of the steel tube body to reduce heat loss and maintain the thermal field stability of the catalytic process.

[0005] Preferably, the steel pipe body is further provided with an additive pipeline. The lower end of the additive pipeline is connected to a gas one-way valve in the tar-mixed steam and additive mixing chamber, and the upper end extends to the ground and is connected to an additive storage tank. The additive storage tank stores H2O and CO2 additives, which can be injected into the tar-mixed steam and additive mixing chamber through the gas one-way valve to regulate the tar quality in real time.

[0006] Preferably, the top outlet of the catalytic tube is connected to a ground oil pipeline, and the end of the ground oil pipeline away from the catalytic tube is connected to an oil storage tank, which is used to collect light tar after sufficient catalysis.

[0007] Preferably, a pressure pump is also connected between the oil storage tank and the catalytic tube. The pressure pump injects water vapor into the catalytic tube using a high-pressure backflushing method to blow away coal dust near the pipe opening and ensure normal pipe flow.

[0008] Preferably, the catalyst layer includes a NiO-Al2O3 catalyst and a NiO-MoO3 catalyst, which are fixedly installed on the tube wall of the honeycomb structure by means of electric heating. The NiO-Al2O3 catalyst is installed in the lower half of the honeycomb structure to promote the cracking of heavy tar, and the NiO-MoO3 catalyst is installed in the upper half of the honeycomb structure to promote the hydrogenation reaction between tar and water vapor, thereby achieving the tar lightening step by step.

[0009] Preferably, the coarse screen has three layers, wherein, from bottom to top, the first layer has a pore size of 1 mm, the second layer has a pore size of 0.5 mm, and the top layer has a pore size of 0.25 mm, so as to achieve the purpose of fully filtering large-diameter coal powder particles; the quartz beads are roasted before filling to avoid the influence of subsequent heating on their properties.

[0010] Preferably, the heating layer includes resistance wires that are evenly distributed on the outer surface of the inner tube to ensure the stability of the temperature of the entire inner tube and to prevent the pyrolysis tar vapor from condensing and falling back while ensuring the stability of the catalytic temperature, thereby improving the tar recovery rate.

[0011] Preferably, the pressure-resistant layer is formed by filling with zirconia ceramic particles, which, together with the steel tube body, ensures the structural stability of the internal catalytic tube when the tube body is damaged by external forces.

[0012] Preferably, the insulation layer is filled with asbestos to ensure that heat inside the pipe is not easily lost and the thermal field is stable, and to reduce energy consumption.

[0013] A method for in-situ pyrolysis of oil-rich coal using an integrated device for in-situ pyrolysis tar filtration and light processing, the method comprising the following steps: Step 1: Use a pressure pump to perform high-pressure backflushing, inject water vapor into the catalytic tube to remove coal dust near the pipe opening and ensure that the pipe is unobstructed; Step 2: Filter the mixture of tar vapor, water vapor and coal powder generated by in-situ pyrolysis through a filter medium filled with multiple layers of coarse screen and quartz beads to remove large-diameter coal powder particles. Step 3: Open the valve on the additive pipeline and inject the H2O and CO2 additives stored in the additive storage tank into the tar mixed steam and additive mixing chamber through the additive pipeline and gas one-way valve. Mix them with the tar vapor that has been filtered out of the coal powder particles in Step 2 and has entered the tar mixed steam and additive mixing chamber to prepare for catalytic conversion. Step 4: The tar vapor mixed in Step 3 is cracked by the NiO-Al2O3 catalyst in the lower half of the honeycomb structure of the catalytic tube, and then the tar vapor is hydrogenated by the NiO-MoO3 catalyst in the upper half of the honeycomb structure of the catalytic tube to achieve the lightening of tar. Step 5: Use the oil storage tank to collect the treated tar vapor through the ground oil pipeline, completing the entire process of tar lightening filtration and transportation.

[0014] The technical effects and advantages of this invention are as follows: 1. In terms of structural design, the filter structure formed by using multi-layer coarse screens and quartz beads as filter media effectively improves the efficiency of preliminary purification of coal powder particles in tar-mixed steam. This filter structure can not only ensure the removal of larger coal powder particles, but also effectively intercept smaller coal powder particles through fine quartz beads, avoiding the risk of coal powder clogging the pipeline and ensuring the smooth flow of the pipeline and the efficiency of transportation.

[0015] 2. By using honeycomb catalytic tubes and segmented NiO-Al2O3 and NiO-MoO3 catalysts, not only is the catalytic area and tube structure stability increased, but more tar can also be converted into lighter components through catalytic reactions. This achieves the orderly separation of tar cracking and hydrogenation reactions, improving the catalytic effect. This design not only meets the needs of large-scale industrial production, but also helps to improve the efficiency and quality of tar lightening.

[0016] 3. By uniformly arranging resistance wires in the heating layer, a constant temperature inside the catalytic pipeline can be maintained, preventing condensation of tar vapor during transmission. This also avoids the reduction of catalyst activity caused by excessively high temperatures, achieving refined temperature control and improving the catalytic conversion effect.

[0017] 4. By filling the pressure-resistant layer with zirconia ceramic particles and using steel pipes, the mechanical strength of the entire system is enhanced, ensuring the long-term stable operation of the pipeline in the underground high-temperature and high-pressure environment. It also provides additional protection for the catalytic tube, avoiding the impact on the catalytic effect due to pipeline deformation or damage.

[0018] 5. The asbestos-filled insulation layer minimizes heat loss, maintains thermal stability during the catalytic process, reduces energy consumption, minimizes energy waste, and improves the system's economic efficiency.

[0019] 6. By setting up additive storage tanks, additive pipelines, and gas check valves, additives can be added in a timely manner. The chemical composition can be adjusted according to changes in the properties of tar, achieving precise control over the lightening of tar and meeting the needs of different industrial applications.

[0020] 7. By setting up a pressure pump for backwashing, the problem of coal powder clogging the pipe opening is avoided, ensuring the smooth flow of the conveying system, improving the stability and reliability of the system, and reducing maintenance costs.

[0021] In summary, this application not only significantly improves the efficiency and quality of tar lightening but also greatly reduces operating costs and extends equipment lifespan, representing a major breakthrough in the field of tar treatment with broad market prospects and application value. The technical solution of this invention can effectively address the industrial processing challenges of in-situ pyrolysis tar from oil-rich coal, promoting the efficient development and utilization of underground oil and gas resources.

[0022] Furthermore, the technical solution of this invention not only effectively filters and lightens the tar from in-situ pyrolysis of oil-rich coal, but also allows for real-time control of tar quality, ensuring the stability and efficiency of the entire catalytic process. These innovative designs of this application greatly improve the economic and environmental benefits of developing oil-rich coal resources, reduce energy consumption, and increase resource utilization. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the pipe of the present invention.

[0024] Explanation of reference numerals in the attached drawings: 1—Valve; 2—Additive storage tank; 3—Additive pipeline; 4—Rock stratum; 5—Catalytic pipe; 6—Catalytic layer; 7—Heating layer; 8—Gas check valve; 9—Tar-mixed steam and additive mixing chamber; 10—Coarse screen; 11—Coal tar and water mixed steam; 12—Filter medium; 13—Insulation layer; 14—Steel pipe body; 15—Pressure-resistant layer; 16—Oil storage tank; 17—Pressure pump; 18—Surface oil pipeline; 19—Pipe wall. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments given in the accompanying drawings.

[0026] See Figures 1-2 As shown, an integrated device for in-situ pyrolysis tar filtration and lightification of oil-rich coal is disclosed. The device includes a steel pipe 14 buried within a rock stratum 4, comprising an inner pipe and an outer pipe. A filtration structure is installed at the bottom of the inner pipe, comprising multiple layers of coarse screens 10 arranged from bottom to top and a filter medium 12 filled with quartz beads. A catalytic conversion structure is installed above the filtration structure, comprising a catalytic tube 5 and a catalytic layer 6. The interior of the catalytic tube 5 has a honeycomb structure, and the catalytic layer 6 is mounted on the wall 19 of the honeycomb structure. The filtration structure and the catalytic conversion structure are integrated. A tar-vapor mixture and additive mixing chamber 9 is formed between the conversion structures, and a one-way gas valve 8 is installed in the tar-vapor mixture and additive mixing chamber 9; the outer pipe body includes a heating layer 7, a pressure-resistant layer 15, and a heat insulation layer 13. The heating layer 7 is tightly attached to the surface of the inner pipe body to maintain the required temperature stability and prevent tar vapor condensation; the pressure-resistant layer 15 is disposed between the steel pipe body 14 and the heating layer 7, and together with the steel pipe body 14, it enhances the structural strength of the pipeline and ensures safe operation; the heat insulation layer 13 is tightly attached to the surface of the steel pipe body 14 to reduce heat loss and maintain the thermal field stability of the catalytic process.

[0027] It should be noted that the catalyst tube 5 and its wall 19 are integrated into a single unit. This integrated design ensures the stability and long-term effectiveness of the catalyst. The catalyst is directly fixed to the tube wall, reducing catalyst loss and improving the efficiency of catalytic conversion. This simplifies the catalyst loading and replacement process, reduces operational complexity, and enhances the system's operational stability.

[0028] By designing the inner cavity of the catalytic tube 5 with a honeycomb structure, the surface area of ​​the catalytic tube is increased, improving catalytic efficiency and enhancing the structural stability of the tube, thus meeting the industrial requirements for tar lightening. The honeycomb design increases the gas flow path, prolongs the contact time between tar vapor and the catalyst, promotes the catalytic reaction, and improves the rate and selectivity of catalytic conversion, achieving efficient tar lightening.

[0029] This embodiment effectively solves the problem of low-quality tar from in-situ pyrolysis of oil-rich coal by employing a meticulously designed filtration and catalytic conversion structure, achieving tar lightening during transportation. In principle, a NiO-Al2O3 catalyst promotes the cracking of heavy tar, while a NiO-MoO3 catalyst promotes the hydrogenation reaction between tar and steam; this segmented catalysis improves the lightening efficiency. This embodiment not only filters coal powder but also significantly improves tar quality, reduces energy consumption, and increases tar recovery through catalytic cracking and hydrogenation reactions.

[0030] In one embodiment, the surface of the steel pipe 14 is also provided with an additive pipe 3. The lower end of the additive pipe 3 is connected to a gas one-way valve 8 in the tar mixing steam and additive mixing chamber 9, and the upper end extends to the ground and is connected to an additive storage tank 2. The additive storage tank 2 stores H2O and CO2 additives. The H2O and CO2 additives can be injected into the tar mixing steam and additive mixing chamber 9 through the gas one-way valve 8 to regulate the tar quality in real time.

[0031] By mixing additives such as H2O and CO2 with tar vapor in the additive mixing chamber 9, the chemical properties of the tar can be controlled, making it more suitable for catalytic cracking and hydrogenation reactions. In terms of effectiveness, the additive mixing chamber 9 in this embodiment improves the utilization rate of additives, enhances the catalytic conversion effect, and enables real-time control of tar quality.

[0032] In one embodiment, the top outlet of the catalytic tube 5 is connected to a ground oil pipeline 18, and the end of the ground oil pipeline 18 away from the catalytic tube 5 is connected to an oil storage tank 16, which is used to collect light tar after sufficient catalysis.

[0033] It should be noted that the pipeline inside the well is connected to the surface pipeline via flanges. Flange connections facilitate pipeline installation and maintenance while ensuring a tight seal at the connection point. The flange connection utilizes the tight fit of bolts and gaskets to prevent the leakage of tar vapor. The technology in this embodiment simplifies the pipeline assembly process, reduces maintenance costs, and improves system operating efficiency.

[0034] In one embodiment, a pressure pump 17 is also connected between the oil storage tank 16 and the catalytic tube 5. The pressure pump 17 injects water vapor into the catalytic tube 5 using a high-pressure backflushing method to blow away coal dust near the pipe opening and ensure normal pipe flow.

[0035] In one embodiment, the catalyst layer 6 includes a NiO-Al2O3 catalyst and a NiO-MoO3 catalyst, which are fixedly installed on the wall 19 of the honeycomb structure by means of electric heating. The NiO-Al2O3 catalyst is installed in the lower half of the honeycomb structure to promote the cracking of heavy tar, and the NiO-MoO3 catalyst is installed in the upper half of the honeycomb structure to promote the hydrogenation reaction between tar and water vapor, thereby achieving the tar lightening step by step.

[0036] This application utilizes electric heating to immobilize the catalyst, ensuring the stability of the catalytic tube and the effective utilization of the catalyst under high-temperature conditions. Electric heating allows for precise temperature control of the catalytic tube, providing optimal reaction conditions for the catalyst and promoting tar cracking and hydrogenation reactions. This embodiment achieves highly efficient catalyst utilization, improving the quality and speed of tar lightening.

[0037] In one embodiment, the multi-layer coarse screen 10 has three layers, wherein, from bottom to top, the first layer has a pore size of 1 mm, the second layer has a pore size of 0.5 mm, and the top layer has a pore size of 0.25 mm, so as to achieve the purpose of fully filtering large-diameter coal powder particles; the quartz beads are roasted before filling to avoid the influence of subsequent heating on their properties.

[0038] In this embodiment, a multi-layer coarse screen 10 with apertures of 1mm, 0.5mm, and 0.25mm from bottom to top effectively removes large-diameter coal dust particles, ensuring unobstructed flow in the conveying pipeline. The quartz bead-filled filter medium 12 further filters finer coal dust. The quartz beads are subjected to high-temperature calcination before filling to eliminate the potential impact of subsequent heating, ensuring a long-lasting and stable filtration effect.

[0039] In one embodiment, the heating layer 7 includes resistance wires that are uniformly distributed on the outer surface of the inner tube to ensure the stability of the temperature of the entire inner tube and to prevent the pyrolysis tar vapor from condensing and falling back while ensuring the stability of the catalytic temperature, thereby improving the tar recovery rate.

[0040] In this embodiment, resistance wires are uniformly arranged in the heating layer 7, ensuring the uniformity and stability of the temperature in the heating layer 7. The resistance wires generate heat when energized, maintaining the temperature required for catalytic conversion while preventing tar vapor from condensing inside the pipes. Furthermore, this embodiment effectively maintains the thermal stability of the catalytic process, improving the efficiency and safety of tar lightening.

[0041] In one embodiment, the pressure-resistant layer 15 is formed by filling with zirconia ceramic particles, which, together with the steel tube body 14, ensures the structural stability of the internal catalytic tube 5 when the tube body is damaged by external forces.

[0042] By employing a pressure-resistant layer 15 and a steel pipe body 14, a robust connection between the pressure-resistant layer 15 and the steel pipe body 14 is ensured, improving the overall pressure resistance of the pipeline. The zirconia ceramic particles filling the pressure-resistant layer 7 can absorb external pressure, prevent pipeline deformation, and protect the internal catalytic tube from damage. The technology of this embodiment enhances the safety and reliability of the pipeline and is suitable for the high-pressure environment of underground in-situ pyrolysis.

[0043] In one embodiment, the insulation layer 13 is filled with asbestos to ensure that heat inside the pipe is not easily lost and the thermal field is stable, and to reduce energy consumption.

[0044] The insulation layer is filled with asbestos, which, as an insulation material, possesses excellent thermal insulation properties and high-temperature resistance. The asbestos-filled insulation layer reduces heat loss, maintains the internal temperature of the pipe, and is beneficial for the catalytic reaction. The technology in this embodiment reduces overall energy consumption and improves the economic benefits of tar lightening. Furthermore, the insulation effect can be further improved by selecting other high-performance insulation materials, such as ceramic fibers or aerogel. Working process or usage process During operation, the device of this application first uses a pressure pump for high-pressure backflushing to remove coal dust near the inlet of the catalytic tube 5, ensuring unobstructed flow. Subsequently, the coal tar and water mixed steam 11 generated by in-situ pyrolysis passes through a multi-layer coarse screen 10 and a filter medium 12 filled with quartz beads, effectively filtering out large-diameter coal dust particles. Next, the mixed steam enters the tar mixed steam and additive mixing chamber 9, where it is thoroughly mixed with gases such as H2O and CO2 injected from the additive storage tank 2, preparing for catalytic conversion. In the catalytic conversion structure, the tar steam first undergoes cracking by a NiO-Al2O3 catalyst, and then hydrogenation by a NiO-MoO3 catalyst, achieving tar lightening. The entire catalytic process is carried out at a stable temperature maintained by the heating layer 7. The uniformly arranged resistance wires in the heating layer 7 ensure a constant catalytic temperature while preventing condensation of the tar steam. The pressure-resistant layer 15 and the steel pipe body 14 provide additional mechanical strength, ensuring the safe operation of the pipeline under underground high-pressure environments. The insulation layer 13 reduces heat loss, maintains a stable thermal field during the catalytic process, and lowers energy consumption. Finally, the treated tar vapor is collected in the storage tank 16 via the ground-based oil pipeline 18, completing the entire process of tar lightening, filtration, and transportation. Throughout the entire operation, the various structural components cooperate to achieve efficient tar lightening and safe transportation, significantly improving the economic and environmental benefits of in-situ pyrolysis of oil-rich coal.

[0045] A method for in-situ pyrolysis of oil-rich coal using an integrated device for in-situ pyrolysis tar filtration and light processing, the method comprising the following steps: Step 1: High-pressure backflushing is performed using pressure pump 17 to inject water vapor into the catalytic tube 5 to remove coal dust near the pipe opening and ensure that the pipe is unobstructed. Step 2: The mixture of tar vapor, water vapor and coal powder generated by in-situ pyrolysis is filtered through a multi-layer coarse screen 10 and a filter medium 12 filled with quartz beads to remove large-diameter coal powder particles. Step 3: Open valve 1 on additive pipeline 3, and inject the H2O and CO2 additives stored in additive storage tank 2 into tar mixed steam and additive mixing chamber 9 through additive pipeline 3 and gas one-way valve 8. Mix with the tar vapor that has been filtered out of coal powder particles in step 2 and has entered tar mixed steam and additive mixing chamber 9 to prepare for catalytic conversion. Step 4: The tar vapor mixed in Step 3 is cracked by the NiO-Al2O3 catalyst in the lower half of the honeycomb structure of the catalytic tube 5, and then the tar vapor is hydrogenated by the NiO-MoO3 catalyst in the upper half of the honeycomb structure of the catalytic tube 5 to achieve the lightening of tar. Step 5: Use the oil storage tank 16 to collect the treated tar vapor through the ground oil pipeline 18 to complete the entire process of tar lightening filtration and transportation.

[0046] This application utilizes a sophisticated structural design to perform in-situ pyrolysis of oil-rich coal. The scientifically designed process not only effectively filters coal particles from the tar vapor, ensuring unobstructed pipeline transport, but also enables catalytic cracking and hydrogenation of the tar during pipeline transport, ultimately producing lighter and higher-quality tar. Furthermore, the device possesses the ability to control tar properties in real time. By supplementing additives as needed, the characteristics of the tar can be adjusted according to actual requirements, meeting diverse industrial application demands.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An integrated device for in-situ pyrolysis tar filtration and lightening of oil-rich coal, characterized in that: The device includes a steel pipe (14) embedded in the rock stratum (4), the steel pipe (14) including an inner pipe and an outer pipe; The inner cavity of the inner tube is provided with a filter structure at the bottom, the filter structure including multiple layers of coarse screen (10) arranged from bottom to top and filter medium (12) filled with quartz beads. A catalytic conversion structure is provided above the filter structure. The catalytic conversion structure includes a catalytic tube (5) and a catalytic layer (6). The interior of the catalytic tube (5) is a honeycomb structure, and the catalytic layer (6) is installed on the tube wall (19) of the honeycomb structure. A tar-mixed vapor and additive mixing chamber (9) is formed between the filtration structure and the catalytic conversion structure, and a gas check valve (8) is provided in the tar-mixed vapor and additive mixing chamber (9). The outer tube body includes a heating layer (7), a pressure-resistant layer (15), and a heat insulation layer (13). The heating layer (7) is tightly attached to the surface of the inner tube body to maintain the required temperature stability and prevent tar vapor from condensing. The pressure-resistant layer (15) is disposed between the steel tube body (14) and the heating layer (7), and together with the steel tube body (14), it enhances the structural strength of the pipeline. The heat insulation layer (13) is tightly attached to the surface of the steel tube body (14) to reduce heat loss and maintain the thermal stability of the catalytic process.

2. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The steel pipe body (14) is also provided with an additive pipe (3). The lower end of the additive pipe (3) is connected to the gas one-way valve (8) in the tar mixing steam and additive mixing chamber (9), and the upper end extends to the ground and is connected to the additive storage tank (2). The additive storage tank (2) stores H2O and CO2 additives. The H2O and CO2 additives can be injected into the tar mixing steam and additive mixing chamber (9) through the gas one-way valve (8) to regulate the tar quality in real time.

3. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The top outlet of the catalytic tube (5) is connected to a ground oil pipeline (18), and the end of the ground oil pipeline (18) away from the catalytic tube (5) is connected to an oil storage tank (16), which is used to collect light tar after sufficient catalysis.

4. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 3, characterized in that: A pressure pump (17) is also connected between the oil storage tank (16) and the catalytic tube (5). The pressure pump (17) injects water vapor into the catalytic tube (5) by high-pressure backflushing to blow away coal dust near the pipe opening and ensure normal flow of the pipe.

5. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The catalyst layer (6) includes a NiO-Al2O3 catalyst and a NiO-MoO3 catalyst, which are fixedly installed on the wall (19) of the honeycomb structure by means of electric heating. The NiO-Al2O3 catalyst is installed in the lower half of the honeycomb structure to promote the cracking of heavy tar, and the NiO-MoO3 catalyst is installed in the upper half of the honeycomb structure to promote the hydrogenation reaction between tar and water vapor, thereby achieving the tar lightening step by step.

6. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The coarse screen (10) has three layers, from bottom to top: the first layer has a pore size of 1 mm, the second layer has a pore size of 0.5 mm, and the top layer has a pore size of 0.25 mm, so as to achieve the purpose of fully filtering large-diameter coal powder particles; the quartz beads are roasted before filling to avoid the influence of subsequent heating on their properties.

7. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The heating layer (7) includes resistance wires, which are evenly distributed on the outer surface of the inner tube to ensure the stability of the temperature of the entire inner tube and prevent the pyrolysis tar vapor from condensing and falling back while ensuring the stability of the catalytic temperature, thereby improving the tar recovery rate.

8. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The pressure-resistant layer (15) is formed by filling with zirconia ceramic particles, which together with the steel tube body (14) ensures the structural stability of the internal catalytic tube (5) when the tube body is damaged by external force.

9. The integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal according to claim 1, characterized in that: The insulation layer (13) is filled with asbestos to ensure that the heat inside the pipe is not easily lost and the thermal field is stable.

10. A method for in-situ pyrolysis of oil-rich coal using an integrated device for in-situ pyrolysis tar filtration and light processing of oil-rich coal as described in any one of claims 1-9, characterized in that, The method includes the following steps: Step 1: Use a pressure pump (17) to perform high-pressure backflushing, inject water vapor into the catalytic tube (5) to remove coal dust near the pipe opening and ensure that the pipe is unobstructed; Step 2: The coal tar and water mixture steam (11) generated by in-situ pyrolysis is filtered through a multi-layer coarse screen (10) and a filter medium (12) filled with quartz beads to remove large-diameter coal powder particles. Step 3: Open valve (1) on additive pipeline (3) and inject the H2O and CO2 additives stored in additive storage tank (2) into tar mixed steam and additive mixing chamber (9) through additive pipeline (3) and gas one-way valve (8). Mix with the tar vapor that has been filtered out of coal powder particles in step 2 and entered tar mixed steam and additive mixing chamber (9) to prepare for catalytic conversion. Step 4: The tar vapor mixed in step 3 is cracked by the NiO-Al2O3 catalyst in the lower half of the honeycomb structure of the catalytic tube (5), and then the tar vapor is hydrogenated by the NiO-MoO3 catalyst in the upper half of the honeycomb structure of the catalytic tube (5) to achieve the lightening of tar. Step 5: Use the oil storage tank (16) to collect the treated tar vapor through the ground oil pipeline (18) to complete the entire process of tar lightening filtration and transportation.

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