Device for finely purifying coal mine gas

Abstract

The utility model provides a device for finely purifying coal mine gas. The device comprises an extraction purification system, a primary purification system and a fine purification system which are connected in sequence, the extraction and purification system is used for pre-treating gas; the primary purification system is used for primarily purifying the gas pretreated by the extraction and purification system; the fine purification system is used for performing fine purification on the gas primarily purified by the primary purification system; the fine purification system comprises a high-gravity reactor, and the high-gravity reactor enables the preliminarily purified gas to be in full contact with a chemical absorbent through high-speed rotation so as to remove carbon dioxide doped in the gas. Fine purification is carried out through the supergravity reactor, the gas-liquid mass transfer rate is remarkably improved under the supergravity field, and the separation efficiency of carbon dioxide and methane is greatly improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to petroleum equipment field especially a device for fine purification coal mine gas. BACKGROUND

[0002] Coal mine gas is a kind of clean and efficient energy, its main component is methane, then nitrogen and oxygen, in addition, it also contains a small amount or trace amount of hydrocarbon gas and carbon dioxide, hydrogen, hydrogen sulfide etc., and its average heat is 35800KJ / m 3 (Equivalent to 1.22kg standard coal).

[0003] In order to make coal mine gas can be reasonably and effectively used, it needs to be purified.But the separation efficiency of methane and carbon dioxide of the existing purification equipment is low, and the present application proposes a device for fine purification coal mine gas aiming at this problem, to improve the separation efficiency of methane and carbon dioxide. CONTENT OF UTILITY MODEL

[0004] The utility model aims at the defect in the above-mentioned technology, provides a device for fine purification coal mine gas to improve the separation efficiency of methane and carbon dioxide in the coal mine gas purification process.

[0005] The utility model aims at realizing in this way: including extraction and purification system, preliminary purification system and fine purification system connected in turn;

[0006] The extraction and purification system is used for pre-treating gas;The preliminary purification system is used for preliminary purification to the gas pretreated by extraction and purification system;The fine purification system is used for fine purification to the gas preliminary purified by preliminary purification system;

[0007] The fine purification system includes supergravity reactor, and the supergravity reactor makes the gas preliminary purified and chemical absorbent fully contact by high-speed rotation, and removes the carbon dioxide mixed therein.

[0008] The above-mentioned device is fine purified by supergravity reactor after pre-treating and preliminary purifying coal mine gas, and the gas-liquid mass transfer rate is significantly improved under supergravity field, so that the separation efficiency of carbon dioxide and methane is greatly improved.

[0009] In a possible implementation, the supergravity reactor of the fine purification system is connected with carbon dioxide resolving tank and first liquid separation tank respectively;

[0010] The first liquid separation tank is further connected with first buffer tank, first vacuum pump and methane storage tank in sequence;

[0011] The carbon dioxide resolving tank is further connected with second liquid separation tank, second buffer tank, second vacuum pump and carbon dioxide storage tank in sequence.

[0012] In a possible implementation, the first liquid separation tank is further connected to an absorbent recovery tank, which is further connected to a third vacuum pump and a high gravity reactor in sequence.

[0013] In a possible implementation, the second liquid separation tank is further connected to an absorbent recovery tank, which is further connected to a third vacuum pump and a high gravity reactor in sequence.

[0014] In a possible implementation, the extraction and purification system comprises a fourth vacuum pump, a purification column, a fourth buffer tank and a compressor connected in sequence.

[0015] In a possible implementation, the primary purification system comprises a first absorption tower, the bottom of the first absorption tower is connected to a flash tank, the flash tank is connected to a desorption tower, the desorption tower is connected to a third liquid separation tank, and the third liquid separation tank is connected to a seventh vacuum pump, a third buffer tank and a high gravity reactor in sequence.

[0016] In a possible implementation, the flash tank is further connected to a fifth vacuum pump, the fifth vacuum pump is connected to a first cooling tank, and the first cooling tank is connected to the first absorption tower.

[0017] In a possible implementation, a second absorption tower is further included, the top of the first absorption tower is connected to the lower part of the second absorption tower through a pipeline, the bottom of the second absorption tower is connected to an eighth vacuum pump through a pipeline, and the eighth vacuum pump is connected to the upper part of the first absorption tower.

[0018] The upper part of the second absorption tower is further connected to a fresh slurry inlet and a venting pipeline.

[0019] In a possible implementation, the desorption tower and the third liquid separation tank are simultaneously connected to a lean liquid tank, the lean liquid tank is further connected to a sixth vacuum pump, the sixth vacuum pump is connected to a second cooling tank, and the second cooling tank is connected to the second absorption tower.

[0020] The lean liquid tank is further connected to a batching tank. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the connection structure of the extraction and purification system of the utility model;

[0022] Figure 2 is a schematic diagram of the connection structure of the primary purification system of the utility model;

[0023] Figure 3 is a schematic diagram of the connection structure of the fine purification system of the utility model;

[0024] Figure 4 is a schematic diagram of the overall connection structure of the fine purification coal mine gas device of the utility model. DETAILED DESCRIPTION

[0025] The application provides a device for purifying coal mine gas. The device is used for purifying coal mine gas after pre-treatment and preliminary purification, and is used for fine purification through a supergravity reactor. The gas-liquid mass transfer rate is significantly improved under the supergravity field, so that the separation efficiency of carbon dioxide and methane is greatly improved.

[0026] The present embodiment is further described below:

[0027] The application provides a device for purifying coal mine gas. The device is used for purifying coal mine gas after pre-treatment and preliminary purification, and is used for fine purification through a supergravity reactor. The gas-liquid mass transfer rate is significantly improved under the supergravity field, so that the separation efficiency of carbon dioxide and methane is greatly improved. Figure 4 The application provides a device for purifying coal mine gas. The device is used for purifying coal mine gas after pre-treatment and preliminary purification, and is used for fine purification through a supergravity reactor. The gas-liquid mass transfer rate is significantly improved under the supergravity field, so that the separation efficiency of carbon dioxide and methane is greatly improved. The extraction and purification system 11 is used for pre-treating gas. Specifically, the gas raw material extracted from the coal mine is compressed and pre-treated. The pre-treatment process removes impurities and water vapor in the raw material gas, and the pre-treated raw material gas is delivered to the preliminary purification system 2. The preliminary purification system 2 is used for preliminary purification of the gas pre-treated by the extraction and purification system 1. The gas raw material pre-treated by the extraction and purification system 1 is a mixed gas with a methane concentration less than 30%, and the preliminary purification system 2 mainly uses the slurry method for preliminary purification, so that the methane concentration in the gas raw material is increased to more than 30%. The gas raw material pre-treated by the preliminary purification system 2 is delivered to the fine purification system 3, and the fine purification system 3 is used for fine purification of the gas pre-treated by the preliminary purification system 2. Specifically, the fine purification system 3 in the application uses a supergravity reactor 311 for fine purification of the gas raw material. The supergravity reactor 311 makes the preliminary purified gas raw material fully contact with the chemical absorbent by high-speed rotation, and removes the mixed carbon dioxide.

[0028] In an alternative embodiment, referring to Figure 3 The supergravity reactor 311 of the fine purification system 3 is connected to the carbon dioxide desorption tank 312 and the first liquid separation tank 331, respectively. The carbon dioxide desorption tank 312 desorbs the carbon dioxide absorbed by the chemical absorbent by changing the surrounding environment. The chemical absorbent that absorbs carbon dioxide is analyzed in the carbon dioxide desorption tank 312, and the temperature and pressure in the analysis tank are changed to make the chemical absorbent react and make the carbon dioxide precipitate. The first liquid separation tank 331 is used for separating the chemical absorbent in the methane gas separated from the supergravity reactor 311.

[0029] Continuing to refer to Figure 3In order to collect and utilize the methane gas separated from the gas raw material, the first separation tank 331 is further connected with a first buffer tank 332, a first vacuum pump 333 and a methane storage tank 334 in sequence. The first buffer tank 332 is arranged to stabilize the pressure of the methane gas separated from the gas raw material. The stabilized methane gas is transported to the methane storage tank 334 by the first vacuum pump 333 for storage.

[0030] With reference to the above Figure 3 In order to recycle the carbon dioxide separated from the supergravity reactor 311, the carbon dioxide desorption tank 312 is further connected with a second separation tank 313, a second buffer tank 314, a second vacuum pump 315 and a carbon dioxide storage tank 316 in sequence. The chemical absorbent in the carbon dioxide is separated by the second separation tank 313, and the pressure of the carbon dioxide gas is stabilized by the second buffer tank 314. The stabilized carbon dioxide gas is transported to the carbon dioxide storage tank 316 by the second vacuum pump 315 for storage.

[0031] With reference to the above Figure 3 In order to recycle the chemical absorbent separated from the methane gas. In the embodiment, the first separation tank 331 is further connected with an absorbent recovery tank 321. The chemical absorbent separated from the methane gas is recovered by the absorbent recovery tank 321, and the recovered chemical absorbent is transported to the supergravity reactor 311 by a third vacuum pump 322 for use, thereby improving the utilization rate.

[0032] In order to further improve the utilization rate of the chemical absorbent, in the embodiment, the second separation tank 313 is also connected with the absorbent recovery tank 321. The chemical absorbent separated from the carbon dioxide gas is recovered by the absorbent recovery tank 321. The recovered chemical absorbent is transported to the supergravity reactor 311 by the third vacuum pump 322 for use.

[0033] In an alternative embodiment, with reference to the above Figure 2 The extraction and purification system 1 comprises a fourth vacuum pump 104, a purification column 102, a fourth buffer tank 103 and a compressor 101 connected in sequence. The gas raw material in the coal mine is extracted to the ground by the fourth vacuum pump 104. Then the gas raw material is transported to the purification column 102, and the gas raw material is purified by the purification column 102, mainly to preliminarily remove the impurities such as dust, coal powder and water vapor mixed therein.

[0034] In a possible embodiment, with reference to the above Figure 3The primary purification system 2 of the present application comprises a first absorption tower 201. The purified gas raw material gas is introduced into the first absorption tower 201 at one third of the height of the first absorption tower 201 after passing through the fourth buffer tank 103 and the compressor 101. At this time, an absorption slurry inlet can be provided at the top of the first absorption tower 201. The absorption slurry moves downward from the top of the first absorption tower 201 due to gravity, and fully contacts the gas raw material gas through countercurrent action, and the low-concentration gas raw material gas is adsorbed by the absorption slurry. It should be noted that the absorption slurry is prepared by mixing a metal organic framework with an organic solvent and water. The bottom of the first absorption tower 201 is connected to a flash tank 202. The flash tank 202 separates gas by changing pressure, and is mainly used to remove nitrogen in the mixed gas. The flash tank 202 is connected to a desorption tower 203. The methane adsorbed in the metal organic framework is desorbed by the desorption tower 203. The principle is that the osmotic pressure inside and outside the metal organic framework membrane in the slurry changes due to pressure change, so that the methane gas is desorbed and released. The desorption tower 203 is connected to a third liquid separator 204. After the liquid in the methane gas is separated by the third liquid separator 204, it is transported to a third buffer tank 206 by a seventh vacuum pump 205. The gas pressure is balanced by the third buffer tank 206, and the gas is stabilized so that it is in a stable state before being transported to the supergravity reactor 311.

[0035] The flash tank 202 is also connected to a fifth vacuum pump 207, which is connected to a first cooling tank 208, which is connected to the first absorption tower 201. The non-target gas such as nitrogen separated from the flash tank 202 is first transported to the first cooling tank 208 for cooling, and then transported to the first absorption tower 201. Since the non-target gas separated from the flash tank 202 contains a certain amount of methane and carbon dioxide gas, it is re-transported to the first absorption tower 201 for further purification of the mixed methane and carbon dioxide gas.

[0036] In one possible implementation, a second absorption tower 209 is also included, and the top of the first absorption tower 201 is connected to the lower part of the second absorption tower 209 by a pipeline. At this time, the first absorption tower 201 does not need to be provided with an absorption slurry inlet, and the absorption slurry inlet is provided at the top of the second absorption tower 209. After entering the second absorption tower 209, the absorption slurry is transported to the upper part of the first absorption tower 201 by a lifting pump. The upper part of the second absorption tower 209 is also provided with a vent line.

[0037] In one possible implementation, the desorption tower 203 and the third liquid separator 204 are simultaneously connected to a lean liquid tank 210. The slurry separated from the desorption tower and the third liquid separator 204 is recycled and re-proportioned by a proportioning tank 211. The re-proportioned slurry is transported to a second cooling tank 213 by a sixth vacuum pump 212, cooled by the second cooling tank 213, and then transported to the second absorption tower 209 for repeated use.

[0038] The working principle of each part of the system is described as follows:

[0039] The extraction and purification system 1 sends the raw gas extracted from the underground by the fourth vacuum pump 104 to the purification column 102 for pretreatment of the raw gas, removes the impurities and water vapor in the raw gas, and then sends it to the fourth buffer tank 103 for smooth processing. The gas is sent to the primary purification system 2 by the compressor 101.

[0040] The primary purification system 2 sends the mixed gas with a methane concentration less than 30% into the first absorption tower 201, with the inlet located 1 / 3 below the absorption tower (the absorption slurry falls from top to bottom in a spray-like manner to accelerate the reaction rate and improve efficiency. The slurry enriched with methane is called rich liquid and is collected at the bottom of the absorption tower, occupying 1 / 3 of the volume of the absorption tower). The slurry enriched at the bottom of the first absorption tower 201 is sent to the flash tank 202 for purification according to the boiling point (this step removes gas components with a boiling point significantly different from that of methane). Since it is a mixed gas, a portion of the methane is separated and sent to a cooler by a vacuum pump for cooling (after flashing, the gas is at a very high temperature, and the entire reaction is carried out at a low temperature of -20°C for optimal reaction effect). The cooled gas is sent back to the first absorption tower 201 for cyclic absorption to increase the methane recovery rate. The gas not absorbed by the slurry is discharged from the top of the second absorption tower 209 after multiple cycles. At this time, the methane concentration is relatively small compared to the raw gas concentration. The second absorption tower 209 has an absorption slurry inlet and a circulating slurry inlet in addition to the exhaust gas outlet. Another part of the rich liquid (slurry enriched with methane) is sent to the desorption tower 203 for methane desorption (by changing the pressure, the osmotic pressure inside and outside the metal-organic framework membrane changes, causing the release of methane gas). The lean liquid (poor liquid after desorption) flows into the lean liquid tank 210, and the desorbed methane gas enters the liquid separator for gas-liquid separation to remove the water in the methane. The separated liquid flows into the lean liquid tank 210, and the dried methane is sent to the buffer tank by a vacuum pump. The lean liquid tank 210 is also equipped with a dosing tank 211 to match the lean liquid to the standard of fresh slurry, which is then sent to the cooling tank by a vacuum pump for cooling treatment to reduce the slurry temperature to -20°C (optimal reaction temperature), and then circulated to the second absorption tower 209. The rich liquid collected at the bottom of the second absorption tower 209 is sent to the first absorption tower 201 for cyclic utilization for methane purification.

[0041] The preliminary purified methane is sent to the latter half of the process for processing, first into the supergravity reactor 311 for processing. In the supergravity reactor 311, the preliminary purified methane and the absorbent are chemically reacted by high-speed rotation of the supergravity reactor 311. The main purpose of this step is to remove carbon dioxide in the methane gas after preliminary purification. The absorbent mainly absorbs carbon dioxide and does not react with other gas components. The methane gas not absorbed by the carbon dioxide chemical absorbent escapes from the upper part of the supergravity reactor 311, and the upper gas is treated, sent to a liquid separation tank to separate the water molecules contained therein, and then sent to a first buffer tank. The methane is extracted by the first vacuum pump and sent to the CH4 storage tank. The carbon dioxide absorbing chemical absorbent is analyzed in the carbon dioxide desorption tank 312. By changing the temperature and pressure in the analysis tank, the chemical reaction is caused to make carbon dioxide precipitate. As described above, the methane is collected, and the carbon dioxide is collected by the liquid separation tank, the buffer tank, and the vacuum pump. At the same time, the absorbent in the liquid separation tank during the collection of methane and carbon dioxide is recycled and reused and sent back to the supergravity reactor 311.

[0042] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

Claims

1. A device for purifying coal mine gas, characterized in that, The system comprises a gas extraction and purification system, a primary purification system and a fine purification system connected in sequence. The gas extraction and purification system is used for pre-treating the gas; the primary purification system is used for primary purification of the gas pre-treated by the gas extraction and purification system; and the fine purification system is used for fine purification of the gas primary purified by the primary purification system. The fine purification system comprises a high gravity reactor, which enables the gas primary purified to fully contact with a chemical absorbent by high-speed rotation, so as to remove the carbon dioxide mixed therein.

2. A device for purifying coal mine gas according to claim 1, characterized in that, The high gravity reactor of the fine purification system is connected with a carbon dioxide resolving tank and a first liquid separator respectively. The first liquid separator is further connected with a first buffer tank, a first vacuum pump and a methane storage tank in sequence. The carbon dioxide resolving tank is further connected with a second liquid separator, a second buffer tank, a second vacuum pump and a carbon dioxide storage tank in sequence.

3. A device for purifying coal mine gas according to claim 2, characterized in that, The first liquid separator is further connected with an absorbent recovery tank, which is further connected with a third vacuum pump and the high gravity reactor in sequence.

4. The device for purifying coal mine gas according to claim 2, characterized in that, The second liquid separator is further connected with the absorbent recovery tank, which is further connected with the third vacuum pump and the high gravity reactor in sequence.

5. The device for purifying coal mine gas according to claim 1, characterized in that, The gas extraction and purification system comprises a fourth vacuum pump, a purification column, a fourth buffer tank and a compressor connected in sequence.

6. The device for purifying coal mine gas according to claim 1, characterized in that, The primary purification system comprises a first absorption tower, the bottom of which is connected with a flash tank, the flash tank is connected with a desorption tower, the desorption tower is connected with a third liquid separator, and the third liquid separator is connected with the high gravity reactor in sequence via a seventh vacuum pump and a third buffer tank.

7. A device for purifying coal mine gas according to claim 6, characterized in that, The flash tank is further connected with a fifth vacuum pump, the fifth vacuum pump is connected with a first cooling tank, and the first cooling tank is connected with the first absorption tower.

8. A device for purifying coal mine gas according to claim 7, characterized in that, The system further comprises a second absorption tower, the top of the first absorption tower is connected with the lower part of the second absorption tower via a pipeline, the bottom of the second absorption tower is connected with an eighth vacuum pump via a pipeline, and the eighth vacuum pump is connected with the upper part of the first absorption tower. The upper part of the second absorption tower is further connected with a fresh slurry inlet and a venting pipeline.

9. A device for purifying coal mine gas according to claim 8, characterized in that, The desorption tower and the third liquid separator are simultaneously connected with a lean liquid tank. The lean liquid tank is further connected with a sixth vacuum pump, the sixth vacuum pump is connected with a second cooling tank, and the second cooling tank is connected with the second absorption tower. The lean liquid tank is further connected with a batching tank.

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