CN114935640B - Simulation experiment system for in-situ decomposition of coal by microorganisms - Google Patents

Abstract

The present invention belongs to the technical field of coal mining, and specifically relates to a simulation experimental system for in-situ decomposition of coal by microorganisms. The system comprises a coal sample reaction system, a stress loading system, a gas access system, a temperature control system, a bacterial liquid storage and injection system, and a gas-liquid separation system. The coal sample reaction system comprises a system base, an experimental box, an insulation layer ①, an insulation layer ②, a reaction table, and a raw coal specimen. The reaction table and the raw coal specimen are located inside the experimental box. The reaction table and the experimental box are both placed on the system base. The raw coal specimen is arranged on the reaction table. The outer side of the experimental box is provided with insulation layers ① and ②. The inside of the experimental box is connected to the gas access system through an air injection pipe; the top of the raw coal specimen is connected to the stress loading system through an air cavity and a pressure element, and the inside of the experimental box is connected to the bacterial liquid storage and injection system through a bacterial liquid injection pipe; the bottom of the reaction table is connected to the gas-liquid separation system; a thermal element is installed inside the experimental box, and the thermal element is connected to the temperature control system.

Description

A simulation experimental system for in-situ microbial decomposition of coal

Technical Field

The invention belongs to the technical field of coal mining, and in particular relates to a simulation experimental system for in-situ microbial decomposition of coal.

Background technique

In order to ensure the security, green and sustainable supply of my country's energy, it is necessary to explore an environmentally friendly, highly secure, low-energy-loss and low-cost mining and utilization model.

At present, the microbial conversion of coal is mainly used to improve the quality of low-rank lignite. If the microorganisms are injected underground under pressure, the coal is decomposed in situ, and then the liquid and gaseous products are extracted, many risks of the original coal mining model are reduced. It is crucial to select microbial populations that are suitable for the coal quality itself and environmental conditions. First, it is necessary to conduct research in the laboratory to provide theoretical and data support for the optimal microbial type. In view of this, it is very necessary to design a simulation experimental system for the in-situ decomposition of coal by microorganisms that takes into account environmental factors such as in-situ stress, air pressure, and temperature. It can accurately evaluate the effect of microbial decomposition of coal, thereby optimizing the microbial population, laying the foundation for the use of microorganisms for direct underground coal gasification and liquefaction research, and helping the "dual carbon" process in the coal field.

Summary of the invention

The present invention provides a simulation experimental system for in-situ microbial decomposition of coal in order to screen out microbial populations for directional degradation of coal, examine the effects of microbial populations on coal degradation at different temperatures and pressures, and provide a reference for in-situ microbial mining of coal.

The present invention adopts the following technical scheme: a simulation experimental system for in-situ decomposition of coal by microorganisms, comprising a coal sample reaction system, a stress loading system, a gas access system, a temperature control system, a bacterial liquid storage and injection system and a gas-liquid separation system, wherein the coal sample reaction system comprises a system base, an experimental box, an insulation layer ①, an insulation layer ②, a reaction table and a raw coal specimen, wherein the reaction table and the raw coal specimen are located inside the experimental box, and the reaction table and the experimental box are both placed on the system base, the raw coal specimen is arranged on the reaction table, the insulation layer ① and the insulation layer ② are arranged outside the experimental box, the insulation layer ① and the experimental box are filled with oil, the inside of the experimental box is connected to the gas access system through an air injection pipe; the top of the raw coal specimen is connected to the stress loading system through an air cavity and a pressure element, and the inside of the experimental box is connected to the bacterial liquid storage and injection system through a bacterial liquid injection pipe; the bottom of the reaction table is connected to the gas-liquid separation system; a thermal element is installed inside the experimental box, and the thermal element is connected to the temperature control system.

The gas access system includes a gas cylinder, a pressure reducing valve, a gas mass flow meter, a needle control valve①, a check valve① and an air inlet pipe. The outlet of the gas cylinder is connected to the gas mass flow meter through the pressure reducing valve. The gas mass flow meter is connected to the inside of the experimental box through the gas injection pipe. The gas injection pipe is provided with a needle control valve① and a check valve①.

The stress loading system includes a gas cylinder, a pressure reducing valve, a gas mass flowmeter, a needle control valve②, a pressure sensor, an air inlet pipe②, an air cavity, a pressure element① and a pressure element②. The outlet of the gas cylinder is connected to the gas mass flowmeter through the pressure reducing valve. The gas mass flowmeter is connected to the air cavity arranged inside the experimental box through the air inlet pipe②. The pressure sensor is arranged on the air inlet pipe②. The air cavity is arranged vertically. A piston is arranged in the air cavity. The end of the piston extends outside the air cavity and is connected to the pressure element①. The pressure element① is arranged on the top of the raw coal specimen.

Furthermore, the bacterial solution storage and injection system includes bacterial solution, an injection pump, a check valve ②, a needle control valve ③ and a bacterial solution injection pipe. The injection pump is connected to the interior of the experimental box through the bacterial solution injection pipe. The bacterial solution injection pipe is provided with a check valve ② and a needle control valve ③, and the injection pump is connected to the bacterial solution.

Furthermore, the gas-liquid separation system includes a filter, a conduit, an exhaust port with a switch valve, a needle control valve ④, a gas-liquid separator, a needle control valve ⑤, a needle control valve ⑥, a drying tower and an automatic extractor. The conduit is provided with an exhaust port with a switch valve and a needle control valve ④. One end of the conduit is connected to the experimental box, and the other end is connected to the gas-liquid separator. A filter is provided at the end of the conduit connected to the experimental box. The gas-liquid separator is respectively connected to the drying tower and the automatic extractor through an air guide pipe and a liquid guide pipe. A needle control valve ⑤ is provided on the air guide pipe, and a needle control valve ⑥ is provided on the liquid guide pipe.

Furthermore, the temperature control system includes a temperature controller connected to the thermal element via a line.

A method for using a simulation experimental system for in-situ microbial decomposition of coal includes the following steps.

S100~Prepare coal samples before the experiment and sterilize the experimental instruments.

S200~Inspect the air tightness of the experimental system: Check that all needle valves and exhaust ports are in the closed state, open the needle control valve①, fill with nitrogen 0.2Mpa, close the needle control valve①, and if the pressure value remains unchanged after stabilization for 12 hours, the system is considered to be in good air tightness.

S300~Set the temperature of the experimental chamber through the temperature controller.

S400~Open the needle control valve①, open the gas cylinder, input a certain amount of nitrogen into the experimental box through the gas mass flow meter to meet the reaction atmosphere environment, close the gas cylinder, and close the needle control valve①.

S500~Open the needle control valve②, open the gas cylinder, the gas pushes the piston in the gas cavity to move, driving the pressure element① to pressurize the experimental coal sample, and the experimental axial pressure is controlled by the pressure sensor.

S600～Inject the target bacteria and nutrient solution, set the bacterial solution loading pressure through the injection pump, open the needle control valve③, start the injection pump, and inject the bacterial solution into the experimental coal sample.

S700~The degradation time is 15 days. After 15 days, open needle control valve ④, needle control valve ⑤ and needle control valve ⑥, open the gas drying tower and automatic extractor to collect the gas and liquid after the reaction.

S800~After the test, the gas, liquid and experimental coal samples after gas-liquid separation are collected and analyzed. At the same time, all needle control valves are closed, the exhaust port switch valve is opened, the needle control valve① is opened, the gas cylinder is opened to introduce nitrogen, and the residual gas in the experimental box is discharged, and then the gas cylinder is closed.

Compared with the prior art, the present invention constructs a simulation experimental system for in-situ microbial decomposition of coal, changes the atmosphere in the reactor through the gas injection system to simulate the underground environment, screens the microbial population that can achieve directional degradation of coal, injects the bacteria and nutrient solution into the raw coal by pressurization, and adjusts the loading pressure, air pressure, temperature and other factors according to the coal quality type and in-situ stress, temperature and air pressure and other conditions, monitors the product type and content, makes an accurate evaluation of the effect of microbial decomposition of coal, and provides a basis for in-situ microbial mining of coal. The present invention has the advantages of easy use, labor saving, safety and reliability, and stable data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a simulation experimental system for in-situ microbial decomposition of coal according to the present invention.

In the figure: 1. Experimental box; 2. Insulation layer ①; 3. Insulation layer ②; 4. Reaction table; 5. Raw coal specimen; 6. Air inlet pipe ①; 7. Air cavity; 8. Pressure element ①; 9. Bacteria solution injection tube; 10. Filter screen; 11. Conduit; 12. Heat element; 13. Gas cylinder; 14. Pressure reducing valve; 15. Gas mass flow meter; 16. Needle control valve ①; 17. Check valve ①; 18. Needle control valve ②; 19. Pressure sensor ; 20. Air inlet pipe ②; 21. Piston; 22. Bacterial liquid; 23. Injection pump; 24. Check valve ②; 25. Needle control valve ③; 26. System base; 27. Needle control valve ④; 28. Gas-liquid separator; 29. Needle control valve ⑤; 30. Needle control valve ⑥; 31. Drying tower; 32. Automatic extraction instrument; 33. Air guide tube; 34. Liquid guide tube; 35. Temperature controller; 36. Exhaust port; 37. Pressure element ②.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

As shown in FIG1 , a simulation experimental system for in-situ microbial decomposition of coal includes a coal sample reaction system, a stress loading system, a gas access system, a temperature control system, a bacterial liquid storage and injection system, and a gas-liquid separation system.

The coal sample reaction system includes a system base 26, an experimental box 1, an insulation layer ①2, an insulation layer ②3, a reaction table 4 and a raw coal specimen 5. The reaction table 4 and the raw coal specimen 5 are located inside the experimental box 1. The reaction table 4 and the experimental box 1 are both placed on the system base 26. The raw coal specimen 5 is set on the reaction table 4. The outer side of the experimental box 1 is provided with insulation layers ①2 and ②3. The insulation layer ①2 and the experimental box 1 are filled with oil for insulation, and the insulation layer ②3 plays a role of heat insulation protection. The inside of the experimental box 1 is connected to the gas access system through the gas injection pipe 6; the top of the raw coal specimen 5 is connected to the stress loading system through the air cavity 7 and the pressure element ①8, and the pressure element ②37 can measure the real-time pressure. The inside of the experimental box 1 is connected to the bacterial liquid storage and injection system through the bacterial liquid injection pipe 9; the bottom of the reaction table 4 is connected to the gas-liquid separation system; the inside of the experimental box is installed with a thermal element, and the thermal element is connected to the temperature control system.

The gas access system includes a gas cylinder 13, a pressure reducing valve 14, a gas mass flow meter 15, a needle control valve ①16, a check valve ①17 and an air inlet pipe 6. The outlet of the gas cylinder 13 is connected to the gas mass flow meter 15 through the pressure reducing valve 14. The gas mass flow meter 15 is connected to the interior of the experimental box 1 through the gas injection pipe 6. The gas injection pipe 6 is provided with a needle control valve ①16 and a check valve ①17.

The stress loading system includes a gas cylinder 13, a pressure reducing valve 14, a gas mass flowmeter 15, a needle control valve ②18, a pressure sensor 19, an air inlet pipe ②20, an air cavity 7, a pressure element ①8 and a pressure element ②37. The outlet of the gas cylinder 13 is connected to the gas mass flowmeter 15 through the pressure reducing valve 14. The gas mass flowmeter 15 is connected to the air cavity 7 arranged inside the experimental box 1 through the air inlet pipe ②20. The pressure sensor 19 is arranged on the air inlet pipe ②20. The air cavity 7 is arranged vertically. A piston 21 is arranged in the air cavity 7. The end of the piston 21 extends to the outside of the air cavity 7 and is connected to the pressure element ①8. The pressure element ①8 is arranged on the top of the raw coal specimen 5.

The bacterial liquid storage and injection system includes a bacterial liquid 22, an injection pump 23, a check valve ②24, a needle control valve ③25 and a bacterial liquid injection pipe 9. The injection pump 23 is connected to the interior of the experimental box 1 through the bacterial liquid injection pipe 9. The bacterial liquid injection pipe 9 is provided with a check valve ②24 and a needle control valve ③25. The injection pump 23 is connected to the bacterial liquid 22.

The gas-liquid separation system includes a filter 10, a conduit 11, an exhaust port 36 with a switch valve, a needle control valve ④27, a gas-liquid separator 28, a needle control valve ⑤29, a needle control valve ⑥30, a drying tower 31 and an automatic extractor 32. The conduit 11 is provided with an exhaust port 36 with a switch valve and a needle control valve ④27. One end of the conduit 11 is connected to the experimental box 1, and the other end is connected to the gas-liquid separator 28. The filter 10 is set at the end of the conduit 11 connected to the experimental box 1. The gas-liquid separator 28 is respectively connected to the drying tower 31 and the automatic extractor 32 through an air guide pipe 33 and a liquid guide pipe 34. The air guide pipe 33 is provided with a needle control valve ⑤29, and the liquid guide pipe 34 is provided with a needle control valve ⑥30.

The temperature control system includes a temperature controller 35 connected to the thermal element 12 via a line.

Among them, the stress pressurizing device has a loading axial pressure range of 0~20Mpa, a control accuracy of 0.001Mpa, and can maintain pressure for 15 days; the temperature controller has a temperature control range of 0~100℃; the gas flow meter: 0~100 standard milliliters per minute; the automatic extractor can automatically perform high-precision extraction according to the solubility.

A method for using a simulation experimental system for in-situ microbial decomposition of coal comprises the following steps:

S100～Prepare coal samples before the experiment and sterilize the experimental instruments;

S200～Inspect the air tightness of the experimental system: Check that all needle valves and exhaust ports are in the closed state, open the needle control valve①, fill with nitrogen 0.2Mpa, close the needle control valve①, and if the pressure value remains unchanged after stabilization for 12 hours, the system is considered to be in good air tightness;

S300～Set the temperature of the experimental box through the temperature controller;

S400~Open the needle control valve①, open the gas cylinder, input a certain amount of nitrogen into the experimental box through the gas mass flow meter to meet the reaction atmosphere environment, close the gas cylinder, and close the needle control valve①;

S500～Open the needle control valve②, open the gas cylinder, the gas pushes the piston in the gas cavity to move, driving the pressure element① to pressurize the experimental coal sample, and the experimental axial pressure is controlled by the pressure sensor;

S600～Inject the target bacteria and nutrient solution, set the bacterial solution loading pressure through the injection pump, open the needle control valve③, start the injection pump, and inject the bacterial solution into the experimental coal sample;

S700～The degradation time is 15 days. After 15 days, open needle control valves ④, ⑤ and ⑥, open the gas drying tower and automatic extractor to collect the gas and liquid after the reaction;

S800~After the test, the gas, liquid and experimental coal samples after gas-liquid separation are collected and analyzed. At the same time, all needle control valves are closed, the exhaust port 36 switch is opened, the needle control valve① is opened, the gas cylinder is opened to introduce nitrogen, and the residual gas in the experimental box is discharged, and then the gas cylinder is closed.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims (3)

1. A simulation experiment system for decomposing coal in situ by microorganisms is characterized in that: the device comprises a coal sample reaction system, a stress loading system, a gas access system, a temperature control system, a bacteria liquid storage and injection system and a gas-liquid separation system, wherein the coal sample reaction system comprises a system base (26), an experiment box body (1), a heat preservation layer ① (2), a heat preservation layer ② (3), a reaction table (4) and a raw coal test piece (5), the reaction table (4) and the raw coal test piece (5) are positioned in the experiment box body (1), the raw coal test piece (5) is arranged on the reaction table (4), the heat preservation layer ① (2) and the heat preservation layer ② (3) are arranged on the outer side of the experiment box body (1), oil is filled between the heat preservation layer ① (2) and the experiment box body (1), and the inside of the experiment box body (1) is connected with the gas access system through an air injection pipe (6); the top of the raw coal test piece (5) is connected with a stress loading system through an air cavity (7) and a pressure element ① (8), and the inside of the experiment box body (1) is communicated with a bacterial liquid storage and injection system through a bacterial liquid injection pipe (9); the bottom of the reaction table (4) is connected with a gas-liquid separation system; a thermal element (12) is arranged on the inner side of the experiment box body (1), and the thermal element (12) is connected with a temperature control system;

The gas access system comprises a gas steel bottle (13), a pressure reducing valve (14), a gas mass flowmeter (15), a needle-type control valve ① (16), a check valve ① (17) and a gas injection pipe (6), wherein an outlet of the gas steel bottle (13) is connected with the gas mass flowmeter (15) through the pressure reducing valve (14), the gas mass flowmeter (15) is communicated with the inside of the experimental box body (1) through the gas injection pipe (6), and the needle-type control valve ① (16) and the check valve ① (17) are arranged on the gas injection pipe (6);

The stress loading system comprises a gas steel bottle (13), a pressure reducing valve (14), a gas mass flowmeter (15), a needle-type control valve ② (18), a pressure sensor (19), an air inlet pipe ② (20), an air cavity (7), a pressure element ① (8) and a pressure element ② (37), wherein an outlet of the gas steel bottle (13) is connected with the gas mass flowmeter (15) through the pressure reducing valve (14), the gas mass flowmeter (15) is connected with the air cavity (7) arranged in the experimental box (1) through the air inlet pipe ② (20), the air cavity ② (20) is provided with the pressure sensor (19), the air cavity (7) is vertically arranged, a piston (21) is arranged in the air cavity (7), the end part of the piston (21) extends out of the air cavity (7) to be connected with the pressure element ① (8), and the pressure element ① (8) is arranged at the top of the raw coal test piece (5);

The bacterial liquid storage and injection system comprises bacterial liquid (22), a liquid injection pump (23), a check valve ② (24), a needle type control valve ③ (25) and a bacterial liquid injection pipe (9), wherein the liquid injection pump (23) is connected with the inside of the experiment box body (1) through the bacterial liquid injection pipe (9), the check valve ② (24) and the needle type control valve ③ (25) are arranged on the bacterial liquid injection pipe (9), and the liquid injection pump (23) is connected with the bacterial liquid (22);

The gas-liquid separation system comprises a filter screen (10), a conduit (11), a needle control valve ④ (27), a gas-liquid separator (28), a needle control valve ⑤ (29), a needle control valve ⑥ (30), a drying tower (31) and an automatic extraction instrument (32), wherein an exhaust port (36) with a switch valve and the needle control valve ④ (27) are arranged on the conduit (11), one end of the conduit (11) is connected with an experimental box (1), the other end of the conduit is connected with the gas-liquid separator (28), the filter screen (10) is arranged at one end of the conduit (11) connected with the experimental box (1), the gas-liquid separator (28) is respectively connected with the drying tower (31) and the automatic extraction instrument (32) through an air duct (33) and the needle control valve ⑤ (29) is arranged on the air duct (33), and the needle control valve ⑥ (30) is arranged on the air duct (34).

2. The simulation experiment system for in-situ decomposition of coal by microorganisms according to claim 1, wherein: the temperature control system comprises a temperature controller (35) connected with the thermal element (12) through a line.

3. A method for using the simulation experiment system for in-situ coal decomposition by microorganisms according to claim 1 or 2, wherein: comprises the steps of,

S100, preparing a coal sample before an experiment, and sterilizing an experimental instrument;

s200, air tightness of an inspection experiment system: checking that all needle valves are in a closed state, opening a needle control valve ①, filling nitrogen gas at 0.2Mpa, closing a needle control valve ①, and stabilizing for 12 hours, wherein the pressure value is unchanged and is regarded as good in system air tightness;

S300, setting the temperature of the experimental box body through a temperature controller;

S400-opening a needle type control valve ①, opening a gas steel cylinder, inputting a certain amount of nitrogen into the experiment box body through a gas mass flowmeter to meet the reaction atmosphere environment, closing the gas steel cylinder, and closing the needle type control valve ①;

S500-opening a needle control valve ②, opening a gas steel cylinder, pushing a piston in the gas cavity to move by gas, driving a pressure element ① to pressurize the experimental coal sample, and controlling the experimental shaft pressure by a pressure sensor;

S600-injecting target strains and nutrient solution, setting bacterial solution loading pressure through an injection pump, opening a needle-type control valve ③, starting the injection pump, and injecting bacterial solution into an experimental coal sample;

S700-degradation time is 15 days, after 15 days, opening a needle-type control valve ④, a needle-type control valve ⑤ and a needle-type control valve ⑥, and opening a gas drying tower and an automatic extraction instrument to collect reacted gas and liquid;

And S800, collecting and analyzing the gas and liquid separated from the experimental coal sample after the test is finished, closing all needle-type control valves, opening an exhaust port (36), opening a needle-type control valve ①, opening a gas steel cylinder, introducing nitrogen, discharging residual gas in the experimental box, and closing the gas steel cylinder.