An experimental device and working method for the effect of high-intensity electric field on kerogen pyrolysis gain

Abstract

The present invention provides an experimental device and working method for the effect of high-intensity electric field on kerogen pyrolysis gain, which belongs to the field of high-voltage power frequency in-situ mining of oil shale, and includes a high-voltage-high-frequency power supply, a nitrogen ventilation bottle, a tubular furnace, an electric field pyrolysis container, and an oil and gas collection system. The present application improves the existing tubular furnace and can provide a high-intensity electric field environment for kerogen during kerogen pyrolysis experiments. By preparing oil shale into dry kerogen particles, the electric field strength that the sample can withstand is enhanced. The zirconia ceramic plates arranged on both sides of the sample can ensure that even if part of the kerogen may be broken down due to chemical reactions occurring during the pyrolysis process, the electric field strength of the remaining kerogen particles is not affected, and the high-intensity electric field pyrolysis experiment can continue. The cracking products under various electric field conditions are then collected by the oil and gas collection system, and in-depth experimental research and verification can be carried out on the kerogen cracking mechanism under the electric field.

Description

Technical Field

[0001] The invention belongs to the field of high-voltage power-frequency in-situ mining of oil shale, and particularly relates to an experimental device and a working method for the effect of a high-intensity electric field on kerogen pyrolysis gain. Background Art

[0002] my country's oil shale resources are currently characterized by thin reservoirs and deep burial depths. In recent years, technologies such as high-voltage-industrial-frequency and high-voltage-high-frequency electric field-based in-situ cracking of oil shale have been shown to achieve concentrated heating of the rock formation, resulting in improved extraction efficiency. When an electric field is applied to oil shale, the electronic and molecular structures of the kerogen macromolecules within the shale layer change, affecting the pyrolysis reaction. While previous studies have theoretically demonstrated that high-intensity electric fields promote the pyrolysis of kerogen molecules, experimental verification remains lacking.

[0003] At present, there are patents that study the pyrolysis effect of oil shale under electric fields. For example, CN201310239405.6 discloses an underground in-situ heating simulation chamber for oil shale, which can heat oil shale or kerogen samples using high voltage electricity up to 10KV under high pressure conditions. However, due to the presence of water in the pores of oil shale, the conductivity of the oil shale increases after the dissolution of some inorganic minerals, resulting in its low conductivity under electric field strength of 10-10 2 Breakdown occurs below 1 V / cm, making it impossible to further increase the electric field for pyrolysis experiments. Therefore, existing technologies cannot experimentally study the promoting effect of high-intensity electric fields on kerogen pyrolysis. Developing an experimental device for the enhanced effect of high-intensity electric fields on kerogen pyrolysis is particularly important.

[0004] Therefore, new technologies are urgently needed to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a device and a system for solving the problems existing in the background technology.

[0006] An experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain, characterized by comprising an electric field pyrolysis system, a nitrogen ventilation bottle, a tubular furnace and an oil and gas collection system;

[0007] The electric field pyrolysis system includes a high-voltage-high-frequency power supply and an electric field pyrolysis container, wherein the electric field pyrolysis container is arranged in a tubular furnace; the electric field pyrolysis container includes a zirconia ceramic cylinder, a metal sealing cover, a metal conductive rod, a zirconia ceramic sheet, an air inlet pipe, an air outlet pipe and an air outlet connector;

[0008] The zirconia ceramic cylinder is a cylinder with openings at both ends. The metal sealing cover is arranged on the openings at both ends of the zirconia ceramic cylinder. Two threaded through holes are provided on the side wall of the zirconia ceramic cylinder, and metal filters are provided in the through holes. The air port connector is threadedly connected to the through holes; the air inlet pipe and the air outlet pipe are respectively provided on the two air port connectors.

[0009] The air inlet pipe passes through the side wall of the tube furnace and is connected to the nitrogen ventilation bottle, and the air outlet pipe passes through the side wall of the tube furnace and is connected to the oil and gas collection system;

[0010] The two ends of the metal sealing cover are respectively provided with a metal conductive rod and a zirconia ceramic sheet; wherein the zirconia ceramic sheet is provided on the end of the metal sealing cover that is inserted into the inner cavity of the zirconia ceramic cylinder; the two metal conductive rods are connected to a high-voltage-high-frequency power supply;

[0011] The oil and gas collection system includes a water-cooled circulating pump and an oil-gas separation device, wherein the condenser pipe of the water-cooled circulating pump is sleeved on the gas outlet pipe, and the gas outlet of the gas outlet pipe is arranged in the oil-gas separation device;

[0012] Valves are provided on the air inlet pipe and the air outlet pipe;

[0013] The connection between the zirconia ceramic cylinder, the gas port connector and the metal sealing cover is provided with a graphite sealing layer.

[0014] The inner wall of the through hole is provided with a frustum.

[0015] The metal sealing cover is threadedly connected to the metal conductive rod.

[0016] The air inlet pipe and the air outlet pipe are both L-shaped.

[0017] A quartz glass support is provided in the tubular furnace, and the electric field pyrolysis container is provided on the quartz glass support.

[0018] The quartz glass support is provided with a container groove and a pipe groove, wherein the zirconia ceramic cylinder is arranged in the container groove, and the air inlet pipe, the air outlet pipe and the air port connector are arranged in the pipe groove.

[0019] One end of the air port connector is open and concave, and the shape of the connecting end of the air inlet pipe and the air outlet pipe with the air port connector is an arc-shaped convex, and the shapes of the concave and convex match each other; and the air port connector and the air inlet pipe or the air port connector and the air outlet pipe are connected by a double-headed nut.

[0020] The zirconia ceramic cylinder is threadedly connected to the metal sealing cover.

[0021] A high-intensity electric field kerogen pyrolysis experimental method, using any of the above-mentioned high-intensity electric field kerogen pyrolysis enhancement experimental devices, is characterized by sequentially performing the following steps:

[0022] Step 1: crushing the oil shale into powder with a fixed particle size, removing inorganic minerals by acid washing to prepare kerogen particles, and placing the kerogen particles in a drying oven to remove excess moisture;

[0023] Step 2: Place the kerogen particles prepared in step 1 into the inner cavity of the zirconia ceramic cylinder, install metal sealing covers with zirconia ceramic sheets at the openings at both ends of the zirconia ceramic cylinder, and after installation, use graphite to seal the connection between the zirconia ceramic cylinder and the metal sealing cover;

[0024] Step 3: Install the metal conductive rod, air inlet pipe and air outlet pipe into the zirconia ceramic cylinder to form an electric field pyrolysis container; install the electric field pyrolysis container onto the quartz glass bracket, and place the quartz glass bracket into the furnace tube of the tube furnace;

[0025] Step 4: Connect the air inlet pipe to the nitrogen ventilation bottle, the air outlet pipe to the oil and gas collection system, and the two metal conductive rods to the high-voltage-high-frequency power supply;

[0026] Step 5: Set the AC voltage of the high-voltage / high-frequency power supply and the temperature rise curve of the tube furnace, open the valves of the nitrogen vent bottle, the air inlet pipe, and the air outlet pipe, and conduct a pyrolysis experiment;

[0027] Step 6: Separate the pyrolysis products through a water-cooled circulating pump and an oil-gas separation device, and collect the products for subsequent research.

[0028] The diameter of the kerogen particles is 0.2 mm.

[0029] Through the above-mentioned design scheme, the present invention can bring the following beneficial effects: the present application improves the existing tubular furnace, and can provide a high-intensity electric field environment for kerogen while conducting kerogen pyrolysis experiments; by preparing oil shale into dry kerogen particles, the electric field strength that the sample can withstand is enhanced, and the sample is placed in a zirconia ceramic container, connected to an AC power supply and heated through a tubular furnace to provide a horizontal electric field environment for kerogen pyrolysis; the zirconia ceramic plates arranged on both sides of the sample can ensure that even if part of the kerogen may be broken down due to chemical reactions occurring during the pyrolysis process, the electric field strength of the remaining kerogen particles is not affected, and the high-intensity electric field pyrolysis experiment can continue; and the cracking products under various electric field conditions are collected through the oil and gas acquisition system, so that in-depth experimental research and verification can be carried out on the kerogen cracking mechanism under the electric field. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0031] Figure 1 Schematic diagram of the structure of the experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain of the present invention;

[0032] Figure 2 It is a vertical cross-sectional schematic diagram of a tube furnace tube of the present invention;

[0033] Figure 3 Schematic diagram of an electric field pyrolysis container in a tubular furnace of the present invention;

[0034] Figure 4 This is a schematic diagram of the connection between the air port connector of the present invention and the air inlet pipe or the air outlet pipe;

[0035] In the figure: 1. High-voltage and high-frequency power supply; 2. Nitrogen ventilation bottle; 3. Tubular furnace; 302. Quartz glass bracket; 4. Electric field pyrolysis container; 401. Graphite sealing layer; 402. Zirconia ceramic cylinder; 403. Metal sealing cover; 404. Metal conductive rod; 405. Zirconia ceramic sheet; 406. Air inlet pipe; 407. Kerogen particles; 408. Metal filter; 409. Air outlet pipe; 410. Air port connector; 5. Water-cooled circulation pump; 6. Oil-gas separation device. DETAILED DESCRIPTION

[0036] This application is further described with reference to the accompanying drawings:

[0037] An experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain, characterized by comprising an electric field pyrolysis system, a nitrogen ventilation bottle 2, a tubular furnace 3 and an oil and gas collection system;

[0038] The electric field pyrolysis system includes a high-voltage-high-frequency power supply 1 and an electric field pyrolysis container 4, wherein the electric field pyrolysis container 4 is arranged in a tubular furnace 3; the electric field pyrolysis container 4 includes a zirconia ceramic cylinder 402, a metal sealing cover 403, a metal conductive rod 404, a zirconia ceramic sheet 405, an air inlet pipe 406, an air outlet pipe 409 and an air port connector 410;

[0039] The zirconia ceramic cylinder 402 is a cylinder with openings at both ends. The metal sealing cover 403 is disposed on the openings at both ends of the zirconia ceramic cylinder 402. Two threaded through holes are disposed on the side wall of the zirconia ceramic cylinder 402, and metal filters 408 are disposed in the through holes. The air port connector 410 is threadedly connected to the through holes. The air inlet pipe 406 and the air outlet pipe 409 are disposed on the two air port connectors 410, respectively.

[0040] The air inlet pipe 406 passes through the side wall of the tube furnace 3 and is connected to the nitrogen ventilation bottle 2, and the air outlet pipe 409 passes through the side wall of the tube furnace 3 and is connected to the oil and gas collection system;

[0041] The two ends of the metal sealing cover 403 are respectively provided with a metal conductive rod 404 and a zirconia ceramic piece 405; wherein the zirconia ceramic piece 405 is provided on the end of the metal sealing cover 403 that is inserted into the inner cavity of the zirconia ceramic cylinder 402; the two metal conductive rods 404 are connected to the high-voltage-high-frequency power supply 1;

[0042] The oil and gas collection system includes a water-cooled circulating pump 5 and an oil-gas separation device 6, wherein the condenser pipe of the water-cooled circulating pump 5 is sleeved on the outlet pipe 409, and the outlet of the outlet pipe 409 is set in the oil-gas separation device 6;

[0043] The air inlet pipe 406 and the air outlet pipe 409 are both provided with valves;

[0044] A graphite sealing layer 401 is provided at the connection between the zirconia ceramic cylinder 402 , the gas port connector 410 and the metal sealing cover 403 .

[0045] The inner wall of the through hole is provided with a truncated cone, and the through hole of the zirconia ceramic cylinder 2 is provided with a concave circular platform, so that the air port connector 410 is in sealing contact with the through hole of the zirconia ceramic cylinder 2;

[0046] The metal sealing cover 403 is threadedly connected to the metal conductive rod 404 .

[0047] The air inlet pipe 406 and the air outlet pipe 409 are both L-shaped.

[0048] A quartz glass support 302 is provided in the tubular furnace 3 , and the electric field pyrolysis container 4 is provided on the quartz glass support 302 .

[0049] The quartz glass support 302 is provided with a container groove and a pipe groove, wherein the zirconia ceramic cylinder 402 is provided in the container groove, and the air inlet pipe 406, the air outlet pipe 409 and the air port connector 410 are provided in the pipe groove.

[0050] One end of the air port connector 410 is open and concave, and the connection ends of the air inlet pipe 406 and the air outlet pipe 409 with the air port connector 410 are in the shape of an arc-shaped protrusion, and the shapes of the concave and the protrusion match each other; and the air port connector 410 and the air inlet pipe 406 or the air port connector 410 and the air outlet pipe 409 are both connected by a double-headed nut.

[0051] The zirconia ceramic cylinder 402 is threadedly connected to the metal sealing cover 403 .

[0052] A high-intensity electric field kerogen pyrolysis experimental method, using the experimental device for the effect of high-intensity electric field on kerogen pyrolysis enhancement as recited in any one of claims 1 to 8, is characterized by sequentially performing the following steps:

[0053] Step 1: crushing the oil shale into powder with a fixed particle size, removing inorganic minerals by acid washing to prepare kerogen particles 407, and placing the kerogen particles 407 in a drying oven to remove excess moisture;

[0054] Step 2: Place the kerogen particles 407 prepared in step 1 into the inner cavity of the zirconia ceramic cylinder 402. Install metal sealing covers 403 with zirconia ceramic sheets 405 at the openings at both ends of the zirconia ceramic cylinder 402. After installation, use graphite to seal the connection between the zirconia ceramic cylinder 402 and the metal sealing covers 403.

[0055] Step 3: Install the metal conductive rod 404, the air inlet pipe 406, and the air outlet pipe 409 into the zirconia ceramic cylinder 402 to form the electric field pyrolysis container 4; install the electric field pyrolysis container 4 onto the quartz glass support 302, and place the quartz glass support 302 into the furnace tube of the tube furnace 3;

[0056] Step 4: Connect the air inlet pipe 406 to the nitrogen ventilation bottle 2, the air outlet pipe 409 to the oil and gas collection system, and connect the two metal conductive rods 404 to the high-voltage-high-frequency power supply 1;

[0057] Step 5: Set the AC voltage of the high-voltage / high-frequency power supply 1 and the temperature rise curve of the tube furnace 3, open the valves of the nitrogen vent bottle 2, the air inlet pipe 406, and the air outlet pipe 409, and conduct a pyrolysis experiment;

[0058] Step 6: Separate the pyrolysis products through the water-cooled circulating pump 5 and the oil-gas separation device 6, and collect the products for subsequent research.

[0059] The diameter of the kerogen particles 407 is 0.2 mm.

[0060] The air inlet pipe 406 and the air outlet pipe 409 are both L-shaped, wherein the short L-shaped section is connected to the air port connector 410;

[0061] The gas port connector 410 is a threaded connector, which is a round tube with a thread on one end. The gas port connector 410 is connected to the zirconia ceramic cylinder 402 through the thread, and a graphite sealing layer 401 is provided at the connection between the gas port connector 410 and the zirconia ceramic cylinder 402.

[0062] A metal filter 408 is provided at the connection between the gas port connector 410 and the side wall of the zirconia ceramic cylinder 402 to prevent kerogen particles from leaving the pyrolysis area through the gas duct;

[0063] One end of the air port connector 410 is open and concave, and the shape of the connecting end of the air inlet pipe 406 and the air outlet pipe 409 with the air port connector 410 is an arc-shaped convex, and the shapes of the concave and convex cooperate with each other; and the air port connector 410 and the air inlet pipe 406 or the air port connector 410 and the air outlet pipe 409 are connected by stud nuts; the air port connector 410 and the air inlet pipe 406 or the air port connector 410 and the air outlet pipe 409 are connected by stud nuts, and the concave design of the air port connector 410 cooperates with the arc-shaped convex design of the air inlet pipe 406 and the air outlet pipe 409 to improve the sealing of the connection;

[0064] The water-cooling circulating pump 5 has its inlet and outlet connected to a condenser pipe, which is provided on the outlet pipe 409. The pumping pressure pushes low-temperature water to circulate in the condenser pipe, thereby reducing the temperature of the pyrolysis products in the outlet pipe 409 as they pass through the condenser pipe section.

[0065] The oil-gas separation device 6 comprises a water bath heating container, a conical flask and a conical flask outlet pipe. The water bath heating container is maintained at 45° C. The conical flask is placed in the water bath heating container. The outlet of the outlet pipe 409 is in the conical flask to collect the pyrolysis oil portion in the pyrolysis product. The conical flask outlet pipe can use a gas collection bag to collect the pyrolysis gas generated by pyrolysis.

[0066] When conducting the experiment, the high-voltage-high-frequency power supply 1 is in AC gear and is connected to the metal sealing cover 403 via a metal conductive rod 404 to provide an electric field for the zirconia ceramic sheet 405-kerogen particles 407-zirconia ceramic sheet 405 sandwich system; the breakdown field strength of the zirconia ceramic sheet 405 is 17 kV / mm, and the relative dielectric constant is 30. The dielectric constant of the kerogen particles 407 is 2-3. When multiple dielectrics are connected in series in an AC electric field, the electric field experienced by the dielectric is inversely proportional to its own relative dielectric constant. Therefore, the 2 mm thick zirconia ceramic sheet 405 has an impact on the electric field of the kerogen particles 407 of less than 5%. Even if the conductivity of some kerogen particles 407 increases due to the pyrolysis reaction during the pyrolysis process, and partial breakdown occurs, the field strength experienced by the zirconia ceramic sheet 405 near the breakdown site will increase, but its ultra-high breakdown voltage will prevent the breakdown from continuing, and the remaining majority of the kerogen particles 407 can still continue the pyrolysis experiment near the set electric field strength.

Claims

1. An experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain, characterized by: It includes an electric field pyrolysis system, a nitrogen ventilation bottle (2), a tubular furnace (3) and an oil and gas collection system; The electric field pyrolysis system comprises a high-voltage-high-frequency power supply (1) and an electric field pyrolysis container (4), wherein the electric field pyrolysis container (4) is arranged in a tubular furnace (3); the electric field pyrolysis container (4) comprises a zirconia ceramic cylinder (402), a metal sealing cover (403), a metal conductive rod (404), a zirconia ceramic sheet (405), an air inlet pipe (406), an air outlet pipe (409), and an air port connector (410); The zirconia ceramic cylinder (402) is a cylinder with openings at both ends. The metal sealing cover (403) is arranged on the openings at both ends of the zirconia ceramic cylinder (402). Two threaded through holes are arranged on the side wall of the zirconia ceramic cylinder (402), and metal filter screens (408) are arranged in the through holes. The air port connector (410) is threadedly connected to the through holes. The air inlet pipe (406) and the air outlet pipe (409) are respectively arranged on the two air port connectors (410). The air inlet pipe (406) passes through the side wall of the tubular furnace (3) and is connected to the nitrogen ventilation bottle (2), and the air outlet pipe (409) passes through the side wall of the tubular furnace (3) and is connected to the oil and gas collection system; The two ends of the metal sealing cover (403) are respectively provided with a metal conductive rod (404) and a zirconia ceramic piece (405); wherein the zirconia ceramic piece (405) is provided on one end of the metal sealing cover (403) inserted into the inner cavity of the zirconia ceramic cylinder (402); the two metal conductive rods (404) are connected to a high-voltage-high-frequency power supply (1); The oil and gas collection system comprises a water-cooled circulating pump (5) and an oil and gas separation device (6), wherein the condenser pipe of the water-cooled circulating pump (5) is sleeved on the gas outlet pipe (409), and the gas outlet of the gas outlet pipe (409) is arranged in the oil and gas separation device (6); The air inlet pipe (406) and the air outlet pipe (409) are both provided with valves; A graphite sealing layer (401) is provided at the connection between the zirconia ceramic cylinder (402), the gas port connector (410) and the metal sealing cover (403).

2. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 1, characterized in that: The inner wall of the through hole is provided with a frustum.

3. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 1, characterized in that: The metal sealing cover (403) is threadedly connected to the metal conductive rod (404).

4. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 1, characterized in that: The air inlet pipe (406) and the air outlet pipe (409) are both L-shaped.

5. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 1, characterized in that: A quartz glass support (302) is provided in the tubular furnace (3), and the electric field pyrolysis container (4) is provided on the quartz glass support (302).

6. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 5, characterized in that: The quartz glass support (302) is provided with a container groove and a pipe groove, wherein the zirconia ceramic cylinder (402) is provided in the container groove, and the air inlet pipe (406), the air outlet pipe (409) and the air port connector (410) are provided in the pipe groove.

7. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 1, characterized in that: One end of the air port connector (410) is concave in opening, and the connection ends of the air inlet pipe (406) and the air outlet pipe (409) with the air port connector (410) are shaped as arc-shaped protrusions, and the shapes of the concave and protrusions match each other; and the air port connector (410) and the air inlet pipe (406) or the air port connector (410) and the air outlet pipe (409) are both connected by stud nuts.

8. The experimental device for the effect of high-intensity electric field on kerogen pyrolysis gain according to claim 1, characterized in that: The zirconia ceramic cylinder (402) is threadedly connected to the metal sealing cover (403).

9. A high-intensity electric field kerogen pyrolysis experimental method, using the high-intensity electric field kerogen pyrolysis enhancement effect experimental device of any one of claims 1 to 8, characterized in that: Follow these steps in order: Step 1: crushing the oil shale into powder with a fixed particle size, removing inorganic minerals by acid washing to prepare kerogen particles (407), and placing the kerogen particles (407) in a drying oven to remove excess moisture; Step 2: Place the kerogen particles (407) prepared in step 1 into the inner cavity of the zirconia ceramic cylinder (402), install metal sealing covers (403) with zirconia ceramic sheets (405) at the openings at both ends of the zirconia ceramic cylinder (402), and after installation, use graphite to seal the connection between the zirconia ceramic cylinder (402) and the metal sealing cover (403); Step 3: Install the metal conductive rod (404), the air inlet pipe (406) and the air outlet pipe (409) to the zirconia ceramic cylinder (402) to form the electric field pyrolysis container (4); install the electric field pyrolysis container (4) on the quartz glass support (302), and place the quartz glass support (302) into the furnace tube of the tubular furnace (3); Step 4: Connect the air inlet pipe (406) to the nitrogen ventilation bottle (2), connect the air outlet pipe (409) to the oil and gas collection system, and connect the two metal conductive rods (404) to the high-voltage-high-frequency power supply (1); Step 5: Set the AC voltage of the high-voltage / high-frequency power supply (1) and the temperature rise curve of the tubular furnace (3), open the valves of the nitrogen vent bottle (2), the air inlet pipe (406), and the air outlet pipe (409), and conduct a pyrolysis experiment; Step 6: Separate the pyrolysis products through the water-cooled circulating pump (5) and the oil-gas separation device (6), and collect the products for subsequent research.

10. The high-intensity electric field kerogen pyrolysis experimental method according to claim 9, characterized in that: The diameter of the kerogen particles (407) is 0.2 mm.

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