Gas membrane-method enrichment, pressurization and destruction heat, electricity and oxygen co-production system and working method thereof

Abstract

The invention discloses a gas membrane-method enrichment, pressurization and destruction heat, electricity and oxygen co-production system and a working method thereof. The system comprises a multi-stage compressor connected to a ventilation air methane inlet; the multi-stage compressor is sequentially connected with the mixer, the heat storage type oxidizer and the expansion machine through the membrane separator, the expansion machine is coaxially connected with the generator to generate power and coaxially connected with the compressor to do work, and alternating current enters the transformer to be converted and then is supplied to a rotating motor of the heat storage type oxidizer to be used or stored by a battery or sold in a grid-connected mode. The smoke-water heat exchanger is connected with a smoke outlet of the expansion machine, and hot water supplies heat to a mining area. Reducing the exhaust gas temperature and preheating the mixed gas; the carbon dioxide trapping unit is connected with a smoke outlet of the waste heat recovery heat exchanger; an oxygen output pipeline is connected with an oxygen outlet of the membrane separator, and a pressure swing adsorption module is arranged to improve the oxygen purity; the starting motor is connected with the compressor, the PLC control system is integrated with a pressure sensor, a temperature sensor and a methane concentration sensor, real-time monitoring and regulation are achieved, and the co-production system is simple, reliable and convenient to operate.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine gas treatment and clean energy co-production, and specifically relates to a gas membrane enrichment, pressurization, destruction, thermoelectric and oxygen co-production system and its working method, which is applicable to the efficient utilization of low-concentration gas and greenhouse gas emission reduction. Background Art

[0002] CH 4 contributes approximately 20% to the global temperature rise and is the second largest greenhouse gas after CO 2 , with the characteristics of short lifespan, strong warming effect, and poor atmospheric stability. Coal mining releases CH 4 from coal seams and surrounding strata, accounting for 9% of the global anthropogenic CH 4 emissions. In addition, low-concentration gas in coal mining gas is as high as 85%. Existing technologies have not had good solutions for the utilization of gas with a CH 4 concentration below 8%, usually directly discharging it. On the one hand, this causes a large waste of high-quality energy, and on the other hand, it also brings serious greenhouse effects.

[0003] The global coal mines emit approximately 40 billion cubic meters of low-concentration gas (CH 4 concentration < 8%) every year, with China accounting for more than 35%. Due to the explosion limit (5% - 15%), this kind of gas cannot be directly used for internal combustion power generation, and traditional thermal oxidation destruction technologies require additional fuel to maintain a high temperature above 800°C, resulting in a treatment cost as high as $0.12 - $0.2 per cubic meter of CH 4 . Data from the International Energy Agency shows that the unused coal mine gas causes a greenhouse effect equivalent to 600 million tons of CO 2 equivalent every year, exceeding the total annual carbon emissions of Germany.

[0004] There are three core bottlenecks in the existing technologies: ① When the membrane separation system purifies low-concentration gas, 30% - 40% of the permeate tail gas still contains 3% - 5% CH 4 , resulting in secondary emissions; ② The thermal efficiency of the rotary regenerative thermal oxidizer (RTO) is less than 55%, and the waste heat of the flue gas above 600°C is not effectively utilized; ③ The steam turbine power generation system requires complex equipment such as boilers and condensers, and the overall energy conversion efficiency is less than 25%.

[0005] Research by the US Environmental Protection Agency shows that the carbon emission intensity of the existing treatment solutions in the whole life cycle is still as high as 0.78 kgCO 2e / kWh, which cannot meet the target of reducing coal mine methane emissions by 75% in 2040 required by the Paris Agreement. In recent years, although the catalytic oxidation co-production system tried in Australia can increase the energy efficiency to 40%, the problem of catalyst deactivation has led to a 23% increase in operating costs.

[0006] CH 4 Emission control has been incorporated into the plan. Although membrane separation can purify gas, it is not deeply coupled with oxidation destruction and energy recovery; although the RTO technology can destroy methane, it has high energy consumption and does not co-produce high-value-added products. In addition, traditional power generation systems rely on steam turbines, which are inefficient and have complex structures.

[0007] Therefore, solving the problem of low-concentration gas in coal mines is of great practical significance in aspects such as clean energy co-production and reducing greenhouse gas emissions. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a gas membrane enrichment, pressurization, destruction, thermoelectric and oxygen co-production system and its working method for solving the problems of deep digestion of residual CH4 in membrane separation tail gas, low efficiency of cascade utilization of high-temperature waste heat, defect of single energy co-production mode, and lag of system dynamic regulation and control in view of the above-mentioned deficiencies in the prior art, effectively reducing greenhouse gas emissions and improving energy utilization.

[0009] The present invention adopts the following technical solutions: A gas membrane enrichment, pressurization, destruction, thermoelectric and oxygen co-production system includes a multi-stage compressor. The inlet end of the multi-stage compressor is connected to the inlet of exhausted air gas. The outlet end of the multi-stage compressor is sequentially connected with a membrane separator, a mixer, a regenerative oxidizer and an expander; The expander is coaxially connected with the multi-stage compressor and is coaxially connected to a generator. The generator is respectively connected to the regenerative oxidizer, a battery or the grid through a transformer; The smoke exhaust port of the expander is sequentially connected with a flue gas-water heat exchanger, a waste heat recovery heat exchanger and a carbon dioxide capture unit. The waste heat recovery heat exchanger is arranged on the connecting pipeline between the mixer and the regenerative oxidizer; The multi-stage compressor, the membrane separator, the mixer, the regenerative oxidizer, the expander, the generator, the transformer, the flue gas-water heat exchanger, the waste heat recovery heat exchanger and the carbon dioxide capture unit are respectively connected to a PLC control system.

[0010] Preferably, the multi-stage compressor is of a three-stage compression structure, and a gas-liquid separator is configured between stages.

[0011] Preferably, the membrane separator adopts a multi-stage membrane separation process and is prepared by using a polymer membrane material or an inorganic membrane material.

[0012] Preferably, the mixer is provided with spiral guide vanes, and the inclination angle of the spiral guide vanes is 30°-60°.

[0013] Preferably, the regenerative oxidizer is a pressurized regenerative oxidizer.

[0014] Preferably, the regenerative oxidizer has a cylindrical rotary structure, including a combustion chamber. A honeycomb ceramic regenerator is arranged in the combustion chamber. The ceramic regenerator divides the combustion chamber into six fan-shaped areas, including a preheating area and a heat storage area. Between the heat storage area and the heat release area, a sealing component is arranged between the chassis and the wall surface of the ceramic regenerator. A rotating shaft is arranged at the center of the ceramic regenerator. A high-temperature flue gas outlet and an oxygen replenishment channel are correspondingly arranged on the upper side wall of the regenerative oxidizer. A low-concentration gas inlet and a heat-exchanged flue gas outlet are correspondingly arranged on the lower side wall of the regenerative oxidizer.

[0015] Preferably, the sealing component is a structure of silicon carbide-reinforced carbon fiber combined with a corrugated spring.

[0016] Preferably, the ceramic regenerator has a honeycomb structure.

[0017] Preferably, the oxygen outlet end of the membrane separator is connected to a pressure swing adsorption module, and the adsorbent of the pressure swing adsorption module is 5A molecular sieve.

[0018] Another technical solution of the present invention, a working method of a gas membrane enrichment pressurization destruction thermoelectric oxygen co-generation system, includes the following steps: The exhausted gas enters a multi-stage compressor through an inlet pipeline and is pressurized to 3-5 bar after three-stage compression; the pressurized exhausted gas enters a membrane separator for three-stage membrane separation; the oxygen enriched on the permeate side of the membrane module is led to a pressure swing adsorption module connected to the membrane separator through an oxygen output pipeline and is purified to a purity of ≥95% through a two-tower pressure swing adsorption process for supplementing the combustion-supporting oxygen of a high-concentration gas power generation system; The enriched gas and the externally input low-concentration gas enter a mixer at a volume ratio of 1:1 to 1:3, and the outlet methane concentration is stabilized at 6%-8%; the mixed gas is preheated through a waste heat recovery heat exchanger, and the preheating heat source is the exhaust waste heat of the regenerative oxidizer; The preheated mixed gas enters the regenerative oxidizer, and the oxygen supplement amount is dynamically adjusted according to the methane concentration to maintain the combustion temperature at 800-1000 °C. After the high-temperature and high-pressure flue gas is discharged, it enters an expander to expand and do work, and the output shaft power drives a generator to generate electricity; the electricity is stabilized by a transformer and supplied to the motors of the compressor and the regenerative oxidizer, and the surplus electricity is sold to the grid; The expander is connected to a flue gas-water heat exchanger through a smoke outlet for heating hot water for heating; the exhaust smoke of the expander enters a carbon dioxide capture unit, and the amine liquid absorption method is used to capture CO 2 To achieve near-zero carbon emissions; The PLC control system monitors the node parameters in real time through pressure sensors, thermocouples and infrared methane sensors, and dynamically adjusts the inter-stage pressure of the compressor, the rotation speed of the rotary valve of the regenerative oxidizer and the gas distribution ratio of the mixer to ensure that the methane destruction rate of the system is ≥ 99%.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects: A gas membrane enrichment, pressurization and destruction thermoelectric and oxygen co-production system realizes the combination of low-concentration gas enrichment and membrane separation technology. The low-concentration gas is enriched through a multi-stage membrane separation process to increase the gas concentration, improve the reaction speed, increase the gas calorific value, increase the temperature rise of the reaction, and is conducive to the methane oxidation and destruction reaction process; an expander is coaxially connected with a generator for power generation. Compared with steam power generation, the system is simple and reliable, convenient to operate, and the exhaust heat is fully utilized; at the same time, oxygen is co-produced and can be used to improve the combustion power generation efficiency of high-concentration gas.

[0020] Furthermore, the multi-stage compressor is set as a three-stage compression structure. The three-stage compression adopts staged pressurization and intermediate cooling design to limit the single-stage compression ratio within a safe range, effectively reduce the outlet gas temperature of each stage, avoid reaching the spontaneous ignition point of the gas mixture, and reduce power consumption compared with single-stage compression.

[0021] Furthermore, a multi-stage membrane separation process is used to separate oxygen in the gas. The membrane separation is based on the difference in the permeation rate of gas components in the membrane material to achieve separation, and the multi-stage membrane separation process can gradually improve the purity of the separated gas.

[0022] Furthermore, the setting of the spiral guide vanes in the mixer enhances the turbulence intensity of the fluid by guiding the gas to form a rotational flow. Under the action of the spiral structure, the mixing uniformity of different concentrations of gas is further improved. The inclination angle design of the guide vanes can adjust the gas flow rate and rotational momentum, extend the gas residence time, and provide necessary conditions for sufficient mixing.

[0023] Furthermore, a pressurized regenerative oxidizer is adopted, which has the advantages of increased reaction speed, reduced volume and enhanced heat exchange capacity compared with the atmospheric pressure RTO.

[0024] Furthermore, a cylindrical rotary regenerative oxidizer is adopted, making the overall structure of the RTO more compact, with a small floor area, convenient for installation and maintenance; compared with the traditional tower structure, the rotary design reduces heat loss, and uses the alternating heat storage and heat release process of the regenerative ceramics to improve the heat recovery efficiency.

[0025] Furthermore, using a silicon carbide-reinforced carbon fiber combined with a corrugated spring structure as a sealing component has the characteristics of fire resistance, heat insulation and flexible design. The silicon carbide-reinforced carbon fiber is heat-resistant, impact-resistant, highly elastic, low-expansion and wear-resistant under the condition of ensuring strength.

[0026] Furthermore, the ceramic heat storage body adopts a honeycomb structure. The honeycomb structure significantly increases the fluid contact area through densely arranged parallel channels, enabling rapid heat transfer between the high-temperature flue gas and the heat storage body. During the endothermic stage, heat energy is efficiently stored, and during the exothermic stage, heat energy is rapidly released, improving efficiency. Moreover, the honeycomb structure further alleviates thermal stress and can extend the service life.

[0027] A working method of a gas membrane enrichment, pressurization, destruction, thermoelectric, and oxygen co-production system. This working method realizes the efficient enrichment and stable combustion of low-concentration gas through multi-stage compression, membrane separation, and dynamic oxygen control, maximizing the methane destruction rate and driving power generation. At the same time, it integrates the cascade utilization of waste heat and amine liquid carbon capture technology to achieve energy self-sufficiency and near-zero carbon emissions, enhancing the environmental protection and economy of the system.

[0028] In summary, the present invention realizes the efficient enrichment and stable oxidation of low-concentration gas through the multi-stage membrane separation and compression synergistic pressurization technology, increasing the methane destruction rate to over 99%. At the same time, it couples waste heat power generation, oxygen co-production, and amine liquid carbon capture processes to form an energy self-circulation system. The system realizes high heat recovery efficiency and near-zero carbon emissions through compact designs such as a rotary regenerative oxidizer and a honeycomb ceramic heat storage body, combining high safety and economy, and solving the problems of low energy efficiency, high carbon emissions, and insufficient resource utilization in traditional technologies.

[0029] The following further describes the technical solutions of the present invention in detail through the drawings and embodiments. Description of the Drawings

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0031] Figure 1 It is the overall diagram of the gas membrane enrichment, pressurization, destruction, thermoelectric, and oxygen co-production system of the present invention; Figure 2 It is the front view of the structure of the regenerative oxidizer (RTO) in the present invention; Figure 3 It is the top view of the structure of the regenerative oxidizer (RTO) in the present invention; Figure 4 It is the sealing structure diagram of the regenerative oxidizer (RTO) in the present invention.

[0032] Wherein: 1. multi-stage compressor; 2. membrane separator; 3. mixer; 4. regenerative oxidizer; 5. expander; 6. generator; 7. transformer; 8. flue gas-water heat exchanger; 9. waste heat recovery heat exchanger; 10. carbon dioxide capture unit; 11. pressure swing adsorption module; 12. starting motor; 13. PLC control system; 4-1. combustion chamber; 4-2. high-temperature flue gas outlet; 4-3. ceramic regenerator; 4-4. oxygen supply channel; 4-5. low-concentration gas inlet; 4-6. flue gas outlet after heat exchange; 4-7. sealing component; 4-8. rotating shaft. Detailed implementation manners

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0037] It should also be understood that the terms used in the specification of the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly dictates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0038] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes and relative positions according to actual needs.

[0040] The present invention provides a gas membrane enrichment, pressurization, destruction, thermoelectric and oxygen co-generation system and its working method. A multi-stage compressor is connected to the inlet of the exhausted air gas to gradually pressurize the exhausted air gas to 3 - 5 bar; a membrane separator, adopting a multi-stage membrane separation process, is used to separate oxygen in the mixed gas and output concentrated gas; a mixer configured with spiral guide vanes is used to mix the low-concentration gas and the exhausted air gas evenly; a regenerative oxidizer connected to the outlet of the mixer is used to generate high-temperature and high-pressure flue gas; an expander connected to the smoke outlet of the regenerative oxidizer is used to receive the high-pressure and high-temperature flue gas, expand and do work to output mechanical energy; the expander is coaxially connected to a generator for power generation and to the compressor for doing work, and the alternating current enters a transformer for conversion and is supplied to the rotating motor of the regenerative oxidizer for use or stored in a battery or sold to the grid; a flue gas-water heat exchanger is connected to the smoke outlet of the expander, and the hot water is used for heating the mining area; the smoke temperature is further reduced while the mixed gas is preheated; a carbon dioxide capture unit is connected to the smoke outlet of the waste heat recovery heat exchanger to reduce the carbon dioxide emission; an oxygen output pipeline is connected to the oxygen outlet of the membrane separator, and a pressure swing adsorption module is configured to improve the oxygen purity; a starting motor is connected to the compressor for the initial start of the system; a PLC control system integrates pressure, temperature and methane concentration sensors for real-time monitoring and regulation.

[0041] Please refer to Figure 1 , a gas membrane enrichment, pressurization, destruction, thermoelectric and oxygen co-generation system of the present invention includes: A multi-stage compressor 1, connected to the inlet of the exhausted air gas, is used to gradually pressurize the exhausted air gas to 3-5 bar; A membrane separator 2, with an operating pressure of 3-5 bar, is used to separate oxygen in the mixed gas and output concentrated gas; The mixer 3 is configured with spiral guide vanes, and the inclination angle of the spiral guide vanes is 30°-60°, preferably 45°, and is used to mix low-concentration gas and exhausted air gas evenly at a volume ratio of 1:1-1:3; A regenerative oxidizer 4, connected to the outlet of the mixer 3, with the pressure of the mixed gas being 3-5 bar, and the regenerative oxidizer 4 is a pressurized regenerative oxidizer, and is used to generate high-temperature and high-pressure flue gas; An expander 5 is connected to the exhaust port of the regenerative oxidizer 4, and is used to receive high-pressure and high-temperature flue gas, and expand to do work to output mechanical energy; The expander 5 is coaxially connected to the generator 6 for power generation and coaxially connected to the multi-stage compressor 1 for doing work. The alternating current enters the transformer 7 for conversion and then is supplied to the rotating motor of the regenerative oxidizer 4 for use, stored in the battery or sold to the grid; A flue gas-water heat exchanger 8 is connected to the exhaust port of the expander 5, and hot water is used for heating the mining area; the exhaust gas temperature is continuously reduced, and at the same time, the mixed gas is preheated; A carbon dioxide capture unit 10 is connected to the exhaust port of the waste heat recovery heat exchanger 9, and is used to reduce the carbon dioxide emission; The oxygen output pipeline is connected to the oxygen outlet of the membrane separator 2, and is configured with a pressure swing adsorption module 11 to improve the oxygen purity; the starting motor 12 is connected to the compressor 1 and is used for the initial start of the system; The PLC control system 13 integrates pressure, temperature and methane concentration sensors for real-time monitoring and control.

[0042] Among them, the multi-stage compressor 1 is preferably a three-stage compression structure, and a gas-liquid separator is configured between stages.

[0043] Preferably, the membrane separator 2 adopts a multi-stage membrane separation process, with an oxygen separation efficiency of ≥90% and a purity of ≥95%.

[0044] Preferably, the membrane separator 2 is preferably a polymer membrane material or an inorganic membrane material.

[0045] Preferably, the heat storage material in the regenerative oxidizer 4 is preferably honeycomb ceramics, with an operating temperature of 800-1000 °C and a methane destruction rate of ≥99%.

[0046] Preferably, the regenerative oxidizer 4 is a cylindrical rotary structure, divided into 6 fan-shaped areas, asFigure 2 and Figure 3 As shown in Figure 3 , the three areas on the left and right are divided into a preheating zone and a heat storage zone, which are sealed between the zones. The structure is preferably a carbon fiber reinforced with silicon carbide in combination with a corrugated spring structure; the gas enters the regenerative oxidizer through the inlet, passes through the preheating zone, the oxidation zone and the heat storage zone, and then is discharged. The heat storage material in the fan-shaped area is driven by a shaft to rotate, continuously switching between the preheating zone and the heat storage zone. The rotating chassis is also sealed with the outer wall surface. As shown in Figure 4 , the heat recovery efficiency is ≥95%. Figure 4 The heat recovery efficiency is ≥95%.

[0047] Preferably, the carbon dioxide capture unit 10 captures CO₂ in the flue gas by the amine liquid absorption method, and the CO₂ capture rate is ≥90%. 2 CO₂ 2 The CO₂ capture rate is ≥90%.

[0048] Preferably, the waste heat recovery heat exchanger 9 is preferably of a plate fin type structure and is used to transfer the heat of the high-temperature flue gas to the gas.

[0049] Preferably, the adsorbent of the pressure swing adsorption module 11 is preferably 5A molecular sieve, which adsorbs and separates gases such as carbon dioxide and hydrogen sulfide in the gas, further purifies oxygen, and the oxygen purity reaches ≥99.5%.

[0050] Preferably, the detection end of the PLC control system 13 is integrated with pressure, temperature and methane concentration sensors to control the speed of the multi-stage compressor 1 and the gas ratio of the mixer.

[0051] The working principle of a gas membrane enrichment, pressurization, destruction, thermoelectric and oxygen co-generation system of the present invention is as follows: 1. Lean gas compression and enrichment Multi-stage compression: The input lean gas (usually with a methane concentration <1%) is gradually pressurized to 3 - 5 bar through a multi-stage compressor. Multi-stage compression reduces the temperature rise, improves the efficiency, and provides the necessary pressure for subsequent membrane separation.

[0052] Membrane separation: The pressurized lean gas enters a multi-stage membrane separator, and oxygen is separated by utilizing the difference in gas permeability, and "enriched gas" with a higher methane concentration (such as the concentration is increased to 30% - 50%) is output, and at the same time, a rich oxygen stream is separated.

[0053] 2. Gas mixing and combustion Mixing and conditioning: The enriched gas is mixed with external low-concentration gas (such as coal mine extracted gas) in a mixer at a volume ratio of 1:1 - 1:3. The spiral guide vanes ensure uniform mixing and adjust the methane concentration to a suitable combustion range (such as 5% - 15%).

[0054] Pressurized oxidation: The mixed gas enters the regenerative oxidizer (RTO), and is oxidized at a high temperature under a pressure of 35 bar, and methane is converted into CO₂ 2With water, high-temperature and high-pressure flue gas at 800 - 1000 °C is generated. The pressurized RTO improves combustion efficiency and maintains system pressure.

[0055] 3. Energy recovery and power generation Expansion power generation: The high-temperature and high-pressure flue gas drives the expander to do work and output mechanical energy. The expander is coaxially connected to the generator for power generation, and part of the mechanical energy directly drives the compressor to reduce external energy consumption.

[0056] Power management: The generated electric energy is processed by a transformer and then used for self - consumption of the system (such as RTO motors), stored in batteries, or sold to the grid, achieving energy self - sufficiency and revenue.

[0057] 4. Waste heat utilization and carbon capture Waste heat recovery: The flue gas discharged from the expander enters the flue gas - water heat exchanger to heat water for mine heating; at the same time, the waste heat preheats the mixed gas before entering the RTO to improve thermal efficiency.

[0058] Carbon capture: The cooled flue gas enters the carbon dioxide capture unit (such as chemical absorption or adsorption method) to reduce CO 2 emissions and achieve low - carbon treatment.

[0059] 5. Oxygen purification and output Oxygen treatment: The oxygen - rich gas generated by membrane separation flows through the pressure swing adsorption (PSA) module for purification to over 90% for industrial use (such as welding, medical treatment, or enhanced combustion processes).

[0060] 6. System control and startup Intelligent regulation: The PLC system integrates pressure, temperature, and methane concentration sensors to adjust parameters such as compressor speed, mixing ratio, and combustion temperature in real - time to ensure safe and efficient operation.

[0061] Startup phase: At initial startup, an external motor drives the compressor, and after the system becomes energy - self - sustaining, it switches to internal power supply.

[0062] To make the objectives, 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 with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0063] The working method of a gas membrane enrichment, pressurization, destruction, and combined heat and power oxygen production system of the present invention is as follows: 1. Gas pressurization and enrichment stage The exhausted air gas (methane concentration 0.5% - 1.5%) enters the multi-stage compressor 1 through the inlet pipeline and is pressurized to 3 - 5 bar after three-stage compression.

[0064] The pressurized exhausted air gas enters the membrane separator 2. Using polymer membrane materials and inorganic membrane materials, three-stage membrane separation is carried out at an operating pressure of 3 - 5 bar. The oxygen enriched on the permeate side of the membrane module is led to the pressure swing adsorption module 11 through the oxygen output pipeline and purified to a purity of ≥95% through a two-tower pressure swing adsorption process for supplementing the combustion-supporting oxygen of the high-concentration gas power generation system.

[0065] 2. Mixing and preheating stage The concentrated gas and the externally input low-concentration gas (methane concentration 1% - 5%) enter the mixer 3 at a volume ratio of 1:1 - 1:3. The mixer 3 is internally provided with 45° spiral guide vanes to stabilize the methane concentration at the outlet at 6% - 8%.

[0066] The mixed gas is preheated by the waste heat recovery heat exchanger 9, and the preheating heat source is the exhaust waste heat of the regenerative oxidizer 4.

[0067] 3. Oxidation destruction and energy recovery stage The preheated mixed gas enters the regenerative oxidizer 4, and its structure is as Figure 2 and Figure 3 shown: The regenerative oxidizer 4 includes a combustion chamber 4-1, a high-temperature flue gas outlet 4-2, regenerative ceramics 4-3, an oxygen supply channel 4-4, a low-concentration gas inlet 4-5, a flue gas outlet 4-6 after heat exchange, a sealing component 4-7, and a rotating shaft 4-8.

[0068] The combustion chamber 4-1 is internally provided with a honeycomb ceramic regenerator 4-3, which alternately stores heat / releases heat in 6 fan-shaped areas. Sealing components 4-7 are arranged between the heat storage area and the heat release area and between the chassis and the wall surface. The structure is as Figure 4 shown. The material is preferably carbon fiber reinforced with silicon carbide and a corrugated spring. The chassis of the ceramic regenerator 4-3 is welded to the rotating shaft 4-8 to play a supporting and rotating role, and the rotation switching period is adjusted according to the gas concentration and speed.

[0069] On the upper side wall of the regenerative oxidizer 4, there are correspondingly arranged a high-temperature flue gas outlet 4-2 and an oxygen replenishment channel 4-4. On the lower side wall of the regenerative oxidizer 4, there are correspondingly arranged a low-concentration gas inlet 4-5 and a flue gas outlet 4-6 after heat exchange. The oxygen replenishment channel 4-4 dynamically adjusts the oxygen replenishment amount according to the methane concentration to maintain the combustion temperature at 800-1000°C. The high-temperature and high-pressure flue gas (pressure 3-5 bar) is discharged through the high-temperature flue gas outlet 4-2.

[0070] The high-temperature flue gas enters the expander 5 to expand and do work, and the output shaft power drives the generator 6 to generate electricity. The electricity is supplied to the compressor 1 and the motor of the regenerative oxidizer 4 after being stabilized by the transformer 7, and the surplus electricity is sold to the grid. The exhaust port of the expander 5 is connected to the flue gas-water heat exchanger 8 to heat hot water for heating.

[0071] 4. Tail gas treatment and resource co-production The exhaust gas of the expander 5 (pressure reduced to atmospheric pressure) enters the carbon dioxide capture unit 10, and the amine liquid absorption method is used to capture CO 2 , realizing near-zero carbon emissions.

[0072] The PLC control system 13 monitors the parameters of key nodes in real time through pressure sensors, thermocouples and infrared methane sensors, and dynamically adjusts the inter-stage pressure of the compressor, the rotation speed of the rotary valve of the regenerative oxidizer 4 and the gas distribution ratio of the mixer to ensure that the methane destruction rate of the system is ≥99%.

[0073] The combination of membrane separation enrichment and high-pressure operation of the regenerative oxidizer 4 increases the oxidation reaction rate by 2-3 times and reduces the equipment volume; the power generation of the expander 5 and waste heat recovery improve the comprehensive energy efficiency of the system; the co-produced oxygen can improve the efficiency of the supporting gas generator set, realizing combined heat, oxygen and power production.

[0074] This embodiment is applicable to the treatment scenario of mine ventilation air methane through modular design, and has the composite benefits of efficient destruction, energy recovery and resource co-production.

[0075] In summary, for a gas membrane enrichment, pressurization, destruction, combined heat, oxygen and power co-production system and its working method of the present invention, through multi-stage compression, membrane separation and dynamic oxygen control, the efficient enrichment and stable combustion of low-concentration gas are realized, the methane destruction rate is maximized and power generation is driven; at the same time, the integrated waste heat cascade utilization and amine liquid carbon capture technology are used to achieve energy self-sufficiency and near-zero carbon emissions, improving the environmental protection and economy of the system, and solving the problems of low energy efficiency, high carbon emissions and insufficient resource utilization rate of traditional technologies.

[0076] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A gas membrane enrichment, pressurization and destruction cogeneration system, characterized in that: It comprises a multi-stage compressor (1), wherein the inlet end of the multi-stage compressor (1) is connected to the inlet of the exhaust gas, and the outlet end of the multi-stage compressor (1) is connected in sequence to a membrane separator (2), a mixer (3), a regenerative thermal oxidizer (4) and an expander (5); The expander (5) is coaxially connected to the multi-stage compressor (1) and is also coaxially connected to the generator (6). The generator (6) is respectively connected to the thermal storage oxidizer (4), a battery or a grid via a transformer (7); The exhaust port of the expander (5) is connected in sequence to a flue gas-water heat exchanger (8), a waste heat recovery heat exchanger (9) and a carbon dioxide capture unit (10); the waste heat recovery heat exchanger (9) is arranged on a connecting pipe between the mixer (3) and the thermal storage oxidizer (4); The multi-stage compressor (1), the membrane separator (2), the mixer (3), the thermal storage oxidizer (4), the expander (5), the generator (6), the transformer (7), the flue gas-water heat exchanger (8), the waste heat recovery heat exchanger (9) and the carbon dioxide capture unit (10) are respectively connected to a PLC control system (13).

2. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 1 is characterized in that: The multi-stage compressor (1) has a three-stage compression structure, and a gas-liquid separator is arranged between the stages.

3. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 1 is characterized in that: The membrane separator (2) adopts a multi-stage membrane separation process and is prepared using polymer membrane materials or inorganic membrane materials.

4. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 1 is characterized in that: A spiral guide vane is provided in the mixer (3), and the inclination angle of the spiral guide vane is 30° to 60°.

5. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 1 is characterized in that: The regenerative thermal oxidizer (4) is a pressurized regenerative thermal oxidizer.

6. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 5 is characterized in that: The regenerative thermal oxidizer (4) is a cylindrical rotating structure, comprising a combustion chamber (4-1), wherein a honeycomb-shaped ceramic regenerative body (4-3) is arranged in the combustion chamber (4-1), and the ceramic regenerative body (4-3) divides the combustion chamber (4-1) into 6 sector-shaped areas, including (3) preheating areas and (3) regenerative thermal areas, between the regenerative thermal areas and the heat release areas, and between the bottom plate and the wall surface of the ceramic regenerative thermal body (4-3) are provided with a sealing component (4-7), and a rotating shaft (4-8) is provided at the center of the ceramic regenerative thermal body (4-3), and a high-temperature flue gas outlet (4-2) and an oxygen supply channel (4-4) are correspondingly arranged on the upper side wall of the regenerative thermal oxidizer (4), and a low-concentration gas inlet (4-5) and a flue gas outlet (4-6) after heat exchange are correspondingly arranged on the lower side wall of the regenerative thermal oxidizer (4).

7. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 6 is characterized in that: The sealing component (4-7) is a silicon carbide-reinforced carbon fiber combined with a corrugated spring structure.

8. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 6 is characterized in that: The ceramic heat storage body (4-3) has a honeycomb structure.

9. The gas membrane enrichment, pressurization and destruction cogeneration system according to claim 1 is characterized in that: The oxygen outlet end of the membrane separator (2) is connected to a pressure swing adsorption module (11), and the adsorbent of the pressure swing adsorption module (11) is 5A molecular sieve.

10. The working method of the gas membrane enrichment, pressurization and destruction cogeneration system according to claim 1 is characterized in that: The following steps are involved: The exhaust gas enters the multi-stage compressor through the inlet pipeline and is compressed to 3~5bar through three-stage compression; the pressurized exhaust gas enters the membrane separator for three-stage membrane separation; the oxygen enriched on the permeate side of the membrane group is led to the pressure swing adsorption module connected to the membrane separator through the oxygen output pipeline, and is purified to a purity of ≥95% through a two-tower pressure swing adsorption process, and is used to supplement the combustion oxygen of the high-concentration gas power generation system; The enriched gas and the low-concentration gas input from the outside are introduced into the mixer at a volume ratio of 1:1~1:3, and the outlet methane concentration is stabilized at 6%~8%; the mixed gas is preheated by the waste heat recovery heat exchanger, and the preheating heat comes from the exhaust waste heat of the thermal oxidizer; The preheated mixed gas enters the regenerative thermal oxidizer, and the oxygen supplement amount is dynamically adjusted according to the methane concentration to maintain the combustion temperature of 800~1000℃. After the high-temperature and high-pressure flue gas is discharged, it enters the expander to expand and do work, and the output shaft power drives the generator to generate electricity; the electricity is stabilized by the transformer and supplied to the compressor and the motor of the regenerative thermal oxidizer, and the surplus electricity is connected to the grid for sale; The expander is connected to the flue gas-water heat exchanger through the exhaust port to heat hot water for heating; the exhaust gas of the expander enters the carbon dioxide capture unit, and the amine liquid absorption method is used to capture CO2 to achieve near-zero carbon emissions; The PLC control system monitors node parameters in real time through pressure sensors, thermocouples and infrared methane sensors, and dynamically adjusts the compressor interstage pressure, the rotary valve speed of the thermal oxidizer and the mixer gas distribution ratio to ensure that the system methane destruction rate is ≥99%.

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