CN103589472A - Mobile low-concentration coal bed gas concentration device and concentration method thereof - Google Patents

Abstract

The invention relates to a mobile low-concentration coalbed gas enrichment device, which includes a PLC centralized control system arranged on a mine flat-bed mine car, a first-stage explosion-proof air compressor in the shell is sequentially connected to a gas pretreatment system through a high-pressure rubber hose, a The characteristic of the stage pressure swing adsorption concentration system is that the stage one pressure swing adsorption concentration system is sequentially connected to the secondary explosion-proof air compressor and the stage two pressure swing adsorption concentration system in the shell through the high-pressure hose. At the same time, the concentration method of the device is disclosed. The device adopts modular integration on the mining flat-bed mine car to realize fast connection and movement, and is suitable for the requirements of extraction and mobile extraction. It is used with a secondary explosion-proof air compressor and a secondary pressure swing adsorption concentration system. Methods Two-stage pressure swing adsorption technology is used to concentrate low-concentration coalbed methane, with daily processing capacity ≥ 24,000 m ³ , methane content in product gas ≥ 80%, methane recovery rate ≥ 60%, and energy consumption per unit of product gas after concentration by the device is ≤ 1.2 kWh/Nm ³ .

Description

A mobile low-concentration coalbed gas enrichment device and enrichment method

technical field

The invention relates to a low-concentration coalbed gas concentration device and a concentration method, in particular to a device and a concentration method for realizing the concentration of low-concentration coalbed gas (coal mine gas) by adopting mobile two-stage pressure swing adsorption technology.

Background technique

Coalbed methane, also known as coal mine gas, is a kind of unconventional natural gas associated with coal and stored in coal seams in an adsorbed state. The main component is CH ₄ . my country is rich in coalbed methane resources, ranking third in the world, and the geological resources of shallow coalbed methane buried below 2000m are about 36 trillion cubic meters. Coalbed methane with a methane concentration between 1% and 30% is called low-concentration coalbed methane, which is mainly exploited through the coal mine gas drainage system. The development and utilization of low-concentration coalbed methane can effectively reduce the amount of wind-exhausted gas, improve mine safety production conditions, improve the level of prevention of gas accidents, and effectively reduce greenhouse gas emissions and generate huge economic benefits.

Coalbed methane is a high-quality and clean energy source. The calorific value of 1 cubic meter of pure coalbed methane is equivalent to 1.13kg of gasoline and 1.21kg of standard coal. Its calorific value is equivalent to that of natural gas, and it can be mixed with natural gas. It hardly produces any waste gas, and it is a good fuel for industry, chemical industry, power generation and residential life. Under the current situation that my country's energy structure is still dominated by coal, it is of great practical significance to develop and utilize coalbed methane resources.

Drainage of coalbed methane is also an important means of preventing coal mine gas accidents. Exploiting coalbed methane before coal mining will reduce the rate of coal mine gas explosions by 70% to 85%. Increasing the utilization rate of coalbed methane will improve the level of prevention of gas accidents. , which has obvious security effects.

Coal bed methane is a kind of greenhouse gas that is extremely destructive to the ecological environment. Its greenhouse effect is about 21 times that of carbon dioxide. If it is directly discharged into the atmosphere, it will cause great damage to the environment.

The comprehensive utilization of coalbed methane has important economic and social benefits for improving and optimizing my country's increasingly severe energy structure, improving mine safety production conditions, ensuring coal mine safety production, reducing coal mine production costs, and reducing air pollution.

In recent years, my country's coalbed methane extraction volume has increased year by year, from 2.23 billion cubic meters in 2005 to 11.5 billion cubic meters in 2011. In the first half of 2012, China's coalbed methane extraction volume reached 6.43 billion cubic meters, an increase of 22.8% year-on-year, of which 5.06 billion cubic meters were extracted from coal mine gas, and 1.63 billion cubic meters were used. The eight relevant regulations stipulate that the methane content of coalbed methane should not be lower than 30%. Therefore, the low-concentration coalbed methane, which accounts for a large proportion of the total coal mine methane emissions, is emptied, and the overall utilization rate of coalbed methane is only 32.3%. Especially in the large and medium-sized coal mines, the utilization rate of coalbed methane is lower due to factors such as poor airtightness of drilling holes and drainage systems during the drainage of coal mine methane. Before 2010, the utilization of coalbed methane in my country was basically limited to the part where the methane concentration was above 30%. The main reason for the low utilization rate of low-concentration coalbed methane in my country was the lack of effective and economical low-concentration coalbed methane utilization technology. and equipment, especially low-concentration coalbed methane concentration and utilization technology and equipment that are suitable for the characteristics of coalbed methane drainage in small and medium coal mines and can be moved between mine drainage sites and mines. This has also become the fundamental reason restricting the development of my country's coalbed methane industry.

At present, the utilization methods of low-concentration coalbed methane in my country are mainly civil and power generation after purification, direct power generation by internal combustion engine, and power generation by catalytic oxidation gas turbine. The purification methods mainly include low-temperature cryogenic method, membrane separation method and pressure swing adsorption method. :

①The product gas methane concentration and recovery rate of the low-temperature cryogenic method are high, but the operation cost of the device and the one-time investment amount are large, and it is only economical when separating a large amount of gas flow, so it is not suitable for small and medium-scale low-concentration coalbed methane extraction, concentration and purification treatment ;

②Mehra process and metal-based liquid absorbent process, the former uses hydrocarbon solvents to separate nitrogen, and the latter uses metal-based liquid absorbents to separate methane and nitrogen, but both are only in the experimental research stage, have not been put into commercial operation, and the technology development is not enough Mature;

③Membrane separation method has the technical advantages of flexibility and convenience, but due to the influence of membrane material selection and membrane manufacturing process, the gas separation effect is not ideal at this stage, and the high investment cost limits its large-scale promotion;

④The pressure swing adsorption method is easy to operate and has strong process practicability. It has been rapidly applied in recent years, such as the pressure swing adsorption technology for extracting low-concentration coalbed methane methane. The CH ₄ content in the product gas is ≥96%, O ₂ ≤0.1%, The effect is good, but this type of technology is only suitable for ground-mounted, large-scale low-concentration coalbed methane treatment. At the same time, the equipment investment is large and the operating cost is high. For medium and low-scale low-concentration coalbed methane treatment, due to the The extraction volume is limited, and the operation time, service life and operation economy of the large-scale pressure swing adsorption concentration technology process do not match the actual needs of the site.

To sum up, my country currently lacks economical and effective coalbed methane concentration technology and equipment suitable for small and medium-scale low-concentration coalbed methane extraction, resulting in a large amount of coalbed methane being evacuated, resulting in extremely low low-concentration utilization. Therefore, in combination with the domestic small and medium-sized coal mine gas drainage with mining and pumping, mobile drainage, and limited drainage scale, research and development of low-concentration coalbed methane concentration and utilization technology and equipment with low unit energy consumption, convenient movement, and excellent performance will be of great importance to It is of great practical significance to effectively control coal mine gas disasters in my country, improve the utilization rate of low-concentration coalbed methane, improve the structure of energy consumption, and reduce environmental pollution.

Contents of the invention

The purpose of the present invention is to overcome the inconvenient movement of the existing ground-mounted large-scale low-concentration coalbed methane enrichment device, poor applicability for small and medium-scale coalbed methane treatment, inability to meet the gas drainage conditions of small and medium-sized mines, and the current domestic coalbed methane utilization field. In view of the adverse effects of small and medium-scale low-concentration coalbed methane treatment technology and equipment, a flexible and mobile low-concentration coalbed methane pressure swing adsorption concentration device is provided. This device can be used alone or combined with multiple units to form a large-scale coalbed methane concentration system. , to meet the special requirements of coalbed methane drainage in small and medium-sized coal mines in China, which are mostly used for extraction and mobile drainage, and can be flexibly moved between various drainage sites and mines, providing a basis for improving the utilization level of coalbed methane drainage in small and medium-sized coal mines Reliable equipment support and mobile two-stage pressure swing adsorption technology are used to achieve the goal of concentrating and utilizing low-concentration coalbed methane methane, while realizing rational and efficient utilization of coalbed methane resources and effectively reducing air pollution caused by coalbed methane emissions.

The technical solution adopted by the present invention to solve the technical problem is to provide a mobile low-concentration coalbed gas concentration device and concentration method.

A mobile low-concentration coalbed methane enrichment device, which includes a PLC centralized control system installed on a mining flat-bed mine car. The first-stage explosion-proof air compressor in the casing is sequentially connected to the gas pretreatment system and the first-stage transformer through a high-pressure rubber hose. The adsorption concentration system is characterized in that: the primary pressure swing adsorption concentration system is sequentially connected to the secondary explosion-proof air compressor and the secondary pressure swing adsorption concentration system in the shell through high-pressure hoses.

Among them: the sequence of the gas pretreatment system includes activated carbon degreaser, several filters, several precision filters, and the pipe connection of the air storage tank of the primary gas compression system.

Among them: the first-stage pressure swing adsorption concentration system includes a gas pretreatment system connecting pipe sequence pipe connected to a vertical two-tower structure pressure swing adsorption tower composed of a first-stage pressure swing adsorption tower, a first-stage pressure swing adsorption product gas storage tank, two The carbon molecular sieve absorbent filled in the primary pressure swing adsorption tower is a non-polar carbon material, and the product number is CMS-220.

Among them: the connecting pipe of the primary pressure swing adsorption concentration system is connected with the secondary explosion-proof air compressor.

Among them: the secondary pressure swing adsorption concentration system includes the secondary explosion-proof air compressor connecting pipe sequence pipe connected to the air storage tank of the secondary gas compression system, a vertical two-tower structure pressure swing adsorption tower composed of a secondary pressure swing adsorption tower, and a secondary pressure swing adsorption tower. One-stage pressure swing adsorption product gas storage tank, two two-stage pressure swing adsorption towers filled with carbon molecular sieve absorbent is non-polar carbon material, the product number is 3KT-172.

Among them: the first flat-bed mine truck is equipped with a first-level explosion-proof air compressor, the second flat-bed mine truck is equipped with a gas pretreatment system, the third flat-bed mine truck is equipped with a first-level PSA concentration system, and the fourth The flat-bed mine truck is equipped with a secondary explosion-proof air compressor, and the fifth flat-bed mine truck is equipped with a secondary pressure swing adsorption concentration system.

A method for concentrating a mobile low-concentration coalbed methane concentration device, using the low-concentration coalbed methane discharged from the mine gas drainage system, and controlling the mobile low-concentration coalbed methane concentration device by a PLC centralized control system to perform one-stage gas compression, gas Oxygen evacuation after pretreatment and primary pressure swing adsorption concentration. Secondary pressure swing adsorption product gas storage tank.

A method for concentrating mobile low-concentration coal-bed methane concentration device, using the low-concentration coal-bed methane discharged from the mine gas drainage system, controlled by the PLC centralized control system, and pressing the low-concentration coal-bed methane into the gas pre-stage through the first-stage explosion-proof air compressor The treatment system is to remove oil through the activated carbon degreaser, remove water and dust through several filters and several precision filters, and then press it into the air storage tank of the first-stage gas compression system, and the gas enters the first-stage pressure swing adsorption concentration system, that is, After the mixed gas is deoxygenated and emptied by the vertical two-tower structure pressure swing adsorption tower, the gas enters the first-stage pressure swing adsorption product gas storage tank. The air compressor is pressed into the two-stage pressure swing adsorption concentration system, that is, compressed to the air storage tank of the two-stage gas compression system, and then enters the vertical two-tower structure pressure swing adsorption tower for nitrogen removal and evacuation of the mixed gas, and then enters the second stage pressure swing adsorption Product gas storage tank.

The beneficial effect of the present invention is: a kind of mobile low-concentration coalbed methane concentrating device described in the present invention adopts modular design, and the whole set of device is composed of five modules, all of which are integrated on the standard-gauge coal mine flat mine car, thereby Realize fast connection and movement, meet the requirements of coalbed methane extraction and mobile extraction, the use of secondary explosion-proof air compressor 10 and secondary pressure swing adsorption concentration system 11, combined with a mobile low-concentration coalbed gas concentration device The concentration method uses two-stage pressure swing adsorption technology to concentrate low-concentration coalbed methane, with a daily processing capacity of more than 24,000 cubic meters, a methane content of more than 80% in the product gas, and a methane recovery rate of more than 60%. The energy consumption of the finished gas is ≤1.2kWh/Nm ³ , and the device can be used alone or form a low-concentration coalbed methane concentration system with multi-machine joint operation.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1 is a schematic diagram of the principle of a mobile low-concentration coalbed methane enrichment device;

Fig. 2 is a structural schematic diagram of a mobile low-concentration coalbed methane enrichment device;

Fig. 3 is a schematic diagram of the PLC centralized control system of a mobile low-concentration coalbed methane concentration device;

Fig. 4 is a schematic diagram of the enrichment method of a mobile low-concentration coalbed methane enrichment device.

In the figure: 1. Primary explosion-proof air compressor, 2. Gas pretreatment system, 3. Activated carbon oil remover, 4. Filter, 5. Precision filter, 6. Primary gas compression system air storage tank, 7. One-stage PSA concentration system, 8. One-stage PSA tower, 9. One-stage PSA product gas storage tank, 10. Two-stage explosion-proof air compressor, 11. Two-stage PSA concentration system, 12. Secondary gas compression system air storage tank, 13. Secondary pressure swing adsorption tower, 14. Secondary pressure swing adsorption product gas storage tank, 15. Flat mine car for mining, 16. Shell, 201. Primary gas compression, 202 . Gas pretreatment, 203. Primary pressure swing adsorption concentration, 204. Secondary gas compression, 205. Secondary pressure swing adsorption concentration.

Detailed ways

Embodiment one

Referring to Fig. 1, Fig. 2 and Fig. 3, a mobile low-concentration coalbed methane enrichment device includes a PLC centralized control system arranged on a mining flat-bed mine car 15, and the first-stage explosion-proof air compressor 1 in the casing 16 passes through The high-pressure rubber hose is sequentially connected to the gas pretreatment system 2 and the first-stage pressure swing adsorption concentration system 7. Adsorption concentration system 11.

Among them: the gas pretreatment system 2 sequentially includes an activated carbon degreaser 3, two filters 4, three precision filters 5, and a first-stage gas compression system air storage tank 6 pipe connections.

Among them: the first-stage pressure swing adsorption concentration system 7 includes a gas pretreatment system 2, a connecting pipe sequence pipe connected to a vertical two-tower structure pressure swing adsorption tower composed of a first-stage pressure swing adsorption tower 8, and a first-stage pressure swing adsorption product gas storage tank 9. The carbon molecular sieve absorbent filled in the two primary pressure swing adsorption towers 8 is a non-polar carbon material, and the product number is CMS-220.

Among them: the first-stage PSA concentration system 7 is connected to the second-stage explosion-proof air compressor 10 by connecting pipes.

Among them: the secondary pressure swing adsorption concentration system 11 includes a secondary explosion-proof air compressor 10 connecting pipe sequence pipes connected to the secondary gas compression system air storage tank 12, and a vertical two-tower structure pressure transformation composed of a secondary pressure swing adsorption tower 13 The adsorption tower, the secondary pressure swing adsorption product gas storage tank 14, and the carbon molecular sieve absorbent filled in the two secondary pressure swing adsorption towers 13 are non-polar carbon materials, and the product number is 3KT-172.

Among them: the first flat-bed mine truck is equipped with a first-class explosion-proof air compressor 1, and the second flat-bed mine truck 15 is equipped with a gas pretreatment system 2, including an activated carbon degreaser 3, two filters 4, three The precision filter 5, the air storage tank 6 of the primary gas compression system, and the third flat-bed mining truck equipped with a primary pressure swing adsorption concentration system 7, including a vertical two-tower structure pressure transformation composed of a primary pressure swing adsorption tower 8 Adsorption tower, primary pressure swing adsorption product gas storage tank 9, the fourth flat mine vehicle for mining is equipped with a secondary explosion-proof air compressor 10, and the fifth flat mine vehicle for mining is equipped with a secondary pressure swing adsorption concentration system 11, including The air storage tank 12 of the secondary gas compression system, the vertical two-tower structure pressure swing adsorption tower composed of the secondary pressure swing adsorption tower 13, and the secondary pressure swing adsorption product gas storage tank 14.

Embodiment two

Refer to Fig. 1, Fig. 2, Fig. 3, Fig. 4, a mobile low-concentration coalbed methane concentration device concentration method uses the low-concentration coalbed methane discharged from the mine gas drainage system, and the mobile low-concentration coalbed methane is controlled by the PLC centralized control system Coalbed methane concentration device, sequentially perform one-stage gas compression 201, gas pretreatment 202, one-stage pressure swing adsorption concentration 203, and then oxygen evacuation. Carry out secondary gas compression 204 and secondary pressure swing adsorption concentration 205 after nitrogen is evacuated into the secondary pressure swing adsorption product gas storage tank 14 .

Embodiment three

Referring to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a mobile low-concentration coalbed methane concentrating method uses the low-concentration coalbed methane discharged from the mine gas drainage system to be controlled by a PLC centralized control system to convert the low-concentration coalbed methane Coal bed gas is pressed into the gas pretreatment system 2 through the first-stage explosion-proof air compressor 1, that is, through the activated carbon degreaser 3 to remove oil, two filters 4, and three precision filters 5 to remove water and dust, and then pressed into the first-stage Gas compression system air storage tank 6, the gas enters the primary pressure swing adsorption concentration system 7, that is, after the mixed gas is deoxygenated and emptied by the vertical two-tower structure pressure swing adsorption tower, the gas enters the primary pressure swing adsorption product gas storage tank 9. The feature is that the gas in the primary pressure swing adsorption product gas storage tank 9 is compressed into the secondary pressure swing adsorption concentration system 11 by the secondary explosion-proof air compressor 10, that is, after being compressed to the air storage tank 12 of the secondary gas compression system After entering the vertical two-tower pressure swing adsorption tower for denitrogenation and evacuation of the mixed gas, it enters the secondary pressure swing adsorption product gas storage tank 14 .

Claims (11)

1. a portable low concentration coal-bed gas concentrating unit, it comprises the PLC centralized monitoring system being arranged on mining dull and stereotyped mine car, one-level Antiexplosion air compressor in shell, by high-pressure rubber pipe be linked in sequence gas pretreatment system, one-level pressure-swing adsorption concentration system, is characterised in that: secondary Antiexplosion air compressor, secondary pressure-swing adsorption concentration system that one-level pressure-swing adsorption concentration system is linked in sequence in shell by high-pressure rubber pipe.

2. a kind of portable low concentration coal-bed gas concentrating unit according to claim 1, is characterized in that: gas pretreatment system sequentially comprises that gac oil eliminator, several strainer, several accurate filter, one-level gas compression system air accumulator pipe connect.

3. a kind of portable low concentration coal-bed gas concentrating unit according to claim 1, it is characterized in that: one-level pressure-swing adsorption concentration system comprises that gas pretreatment system pipe connecting is sequentially managed and connects vertical two tower structure pressure-swing absorbers, the one-level pressure-variable adsorption gas product storage tank consist of one-level pressure-swing absorber, in two one-level pressure-swing absorbers, filling carbonaceous molecular sieve absorption agent is nonpolar carbon materials, and production number is CMS-220.

4. a kind of portable low concentration coal-bed gas concentrating unit according to claim 2, it is characterized in that: one-level pressure-swing adsorption concentration system comprises that gas pretreatment system pipe connecting is sequentially managed and connects vertical two tower structure pressure-swing absorbers, the one-level pressure-variable adsorption gas product storage tank consist of one-level pressure-swing absorber, in two one-level pressure-swing absorbers, filling carbonaceous molecular sieve absorption agent is nonpolar carbon materials, and production number is CMS-220.

5. a kind of portable low concentration coal-bed gas concentrating unit according to claim 1, it is characterized in that: one-level pressure-swing adsorption concentration system pipe connecting pipe connects secondary Antiexplosion air compressor, secondary pressure-swing adsorption concentration system comprises that secondary Antiexplosion air compressor pipe connecting is sequentially managed and connects secondary gas compression system air accumulator, the vertical two tower structure pressure-swing absorbers that consist of secondary pressure-swing absorber, secondary pressure-variable adsorption finished product gas storage tank, in two secondary pressure-swing absorbers, filling carbonaceous molecular sieve absorption agent is nonpolar carbon materials, and production number is 3KT-172.

6. a kind of portable low concentration coal-bed gas concentrating unit according to claim 2, it is characterized in that: one-level pressure-swing adsorption concentration system pipe connecting pipe connects secondary Antiexplosion air compressor, secondary pressure-swing adsorption concentration system comprises that secondary Antiexplosion air compressor pipe connecting is sequentially managed and connects secondary gas compression system air accumulator, the vertical two tower structure pressure-swing absorbers that consist of secondary pressure-swing absorber, secondary pressure-variable adsorption finished product gas storage tank, in two secondary pressure-swing absorbers, filling carbonaceous molecular sieve absorption agent is nonpolar carbon materials, and production number is 3KT-172.

7. a kind of portable low concentration coal-bed gas concentrating unit according to claim 3, it is characterized in that: one-level pressure-swing adsorption concentration system pipe connecting pipe connects secondary Antiexplosion air compressor, secondary pressure-swing adsorption concentration system comprises that secondary Antiexplosion air compressor pipe connecting is sequentially managed and connects secondary gas compression system air accumulator, the vertical two tower structure pressure-swing absorbers that consist of secondary pressure-swing absorber, secondary pressure-variable adsorption finished product gas storage tank, in two secondary pressure-swing absorbers, filling carbonaceous molecular sieve absorption agent is nonpolar carbon materials, and production number is 3KT-172.

8. a kind of portable low concentration coal-bed gas concentrating unit according to claim 4, it is characterized in that: one-level pressure-swing adsorption concentration system pipe connecting pipe connects secondary Antiexplosion air compressor, secondary pressure-swing adsorption concentration system comprises that secondary Antiexplosion air compressor pipe connecting is sequentially managed and connects secondary gas compression system air accumulator, the vertical two tower structure pressure-swing absorbers that consist of secondary pressure-swing absorber, secondary pressure-variable adsorption finished product gas storage tank, in two secondary pressure-swing absorbers, filling carbonaceous molecular sieve absorption agent is nonpolar carbon materials, and production number is 3KT-172.

9. according to a kind of portable low concentration coal-bed gas concentrating unit described in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8, it is characterized in that: first mining dull and stereotyped mine car is loaded with one-level Antiexplosion air compressor, second mining dull and stereotyped mine car is loaded with gas pretreatment system, the 3rd mining dull and stereotyped mine car is loaded with one-level pressure-swing adsorption concentration system, the 4th mining dull and stereotyped mine car is loaded with secondary Antiexplosion air compressor, and the 5th mining dull and stereotyped mine car is loaded with secondary pressure-swing adsorption concentration system.

10. the concentration method of a portable low concentration coal-bed gas concentrating unit, utilize the low concentration coal-bed gas of mine gas drainage system discharge, by PLC centralized monitoring system, control portable low concentration coal-bed gas concentrating unit, after order is carried out one-level gas compression, gas pre-treatment, one-level pressure-swing adsorption concentration, oxygen is emptying, is characterised in that: the one-level pressure-variable adsorption gas product after one-level pressure-swing adsorption concentration sequentially carries out entering secondary pressure-variable adsorption finished product gas storage tank after secondary gas compression, secondary pressure-swing adsorption concentration nitrogen purge.

The concentration method of 11. 1 kinds of portable low concentration coal-bed gas concentrating uniies, utilize the low concentration coal-bed gas of mine gas drainage system discharge, by PLC centralized monitoring system, controlled, low concentration coal-bed gas is pressed into gas pretreatment system by one-level Antiexplosion air compressor, by the oil removing of gac oil eliminator, several strainers, several accurate filters dewater and dedusting after, be pressed into one-level gas compression system air accumulator, gas enters one-level pressure-swing adsorption concentration system, by vertical two tower structure pressure-swing absorbers carry out mixed gas deoxygenation emptying after, gas enters one-level pressure-variable adsorption gas product storage tank, be characterised in that: the gas in one-level pressure-variable adsorption gas product storage tank is pressed into secondary pressure-swing adsorption concentration system by secondary Antiexplosion air compressor, be compressed to enter after secondary gas compression system air accumulator vertical two tower structure pressure-swing absorbers carry out mixed gas denitrogenate emptying after, enter secondary pressure-variable adsorption finished product gas storage tank.

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