Argon recovery and purification system

Abstract

According to the argon recovery and purification system, an argon pretreatment module is connected in series with a separator, an activated carbon adsorption tower and a high-efficiency filter, so that macromolecular impurities such as particulate matters, oil, hydrocarbons and dust can be efficiently removed, and a clean gas source is provided for subsequent nano catalytic reaction and membrane separation; in the multistage fixed bed nano catalytic reactor, a composite nano catalyst bed layer and an electric heating wire have a synergistic effect, CO and O2 can be quickly and thoroughly converted into CO2 under moderate temperature and pressure, active sites on the surface of a nano-scale catalyst are rich, and the carbon deposition rate and the inactivation rate are greatly reduced; the screw compressor and the water cooler are combined for use, and the energy efficiency of the compression and cooling process is greatly improved compared with a traditional high-temperature and high-pressure process; preliminary separation is completed through hollow fiber membrane separation at normal temperature and normal pressure, after rectification load is relieved, argon-rich gas is precooled through a cold box and enters a low-temperature rectification tower after membrane separation, and high-purity argon gas can be stably prepared in combination with a liquid nitrogen refrigerant condensation evaporator and a spiral pipe type liquefier.

Description

Technical Field

[0001] This application relates to the field of argon gas recovery and purification technology, and specifically to an argon gas recovery and purification system. Background Technology

[0002] Argon is a chemically stable rare gas widely used in industries such as cemented carbide manufacturing, precision ceramic sintering, semiconductor production, and metal welding and heat treatment. With the development of high-end manufacturing, the demand for high-purity argon continues to grow. However, since argon accounts for only about 0.93% of air, its separation and purification process is complex and costly. Therefore, industrial processes often require the recovery and purification of used argon to reduce costs and improve resource utilization. Currently, mainstream argon recovery processes mainly employ precious metal catalysts combined with distillation or membrane separation, but in practical applications, problems such as incomplete impurity removal, easy catalyst deactivation, high system energy consumption, and low separation efficiency still exist. Specifically, waste gases often contain impurities such as CO, O2, N2, and VOCs, which are difficult to completely purify using existing pretreatment processes, affecting the efficiency of subsequent catalysis and separation. Precious metal catalysts are prone to deactivation due to carbon buildup, and the removal of CO and O2 typically requires high temperature and pressure, resulting in high energy consumption. Furthermore, because argon and nitrogen have similar physical properties, membrane separation has poor selectivity, making it difficult to obtain electronic-grade argon, and byproduct nitrogen is not effectively recovered, leading to low resource utilization. Therefore, there is an urgent need to develop an integrated system that is highly efficient, low-energy, and can synergistically recover argon and nitrogen to improve argon purity, reduce operating costs, and achieve efficient resource reuse. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this application is to provide an argon gas recovery and purification system to solve the problems mentioned in the background art.

[0004] According to one aspect of this application, an argon gas recovery and purification system includes:

[0005] Argon pretreatment module (1), the inlet of which is used to introduce recycled argon to remove particulate matter, oil and hydrocarbon impurities from the recycled argon;

[0006] A screw compressor (3) has its inlet connected to the outlet of the argon pretreatment module (1) to pressurize the pretreated argon.

[0007] The nanocatalytic reaction module (2) has its inlet connected to the outlet of the screw compressor (3). The nanocatalytic reaction module (2) includes at least two catalytic reactors connected in series. The catalytic reactors are filled with composite nanocatalysts, which are used to react carbon monoxide and oxygen in the recovered argon gas to generate carbon dioxide through the catalytic effect of the composite nanocatalysts, so as to obtain crude argon gas.

[0008] The cooling device (4) has its inlet connected to the outlet of the nanocatalytic reaction module (2) and is used to cool the crude argon gas.

[0009] Hollow fiber membrane module (5), whose inlet is connected to the outlet of the cooling device (4), is used to selectively separate argon and nitrogen by permeation;

[0010] A cold box (65) is used to pre-cool the argon-rich gas separated from the hollow fiber membrane module (5);

[0011] The distillation system (6) has its inlet connected to the outlet of the cold box (65) and is used to distill and purify the pre-cooled argon-rich gas to electronic-grade high-purity argon gas, and to return the nitrogen-rich gas discharged from the distillation column to the inlet of the hollow fiber membrane module (5) for recycling.

[0012] Preferably, the argon pretreatment module (1) includes a separator (11), an activated carbon adsorption tower (12), and a filter (13) connected in series. The inlet of the separator (11) is supplied with recovered argon gas, the inlet of the activated carbon adsorption tower (12) is connected to the outlet of the separator (11), the inlet of the filter (13) is connected to the outlet of the activated carbon adsorption tower (12), and the outlet of the filter (13) is connected to the inlet of the screw compressor (3).

[0013] Preferably, the nanocatalytic reaction module (2) includes a fixed bed reactor (21), a catalyst bed (22), and an electric heating wire. The fixed bed reactor (21) is provided with a catalytic reaction tube, and the catalytic reaction tube is filled with a composite nanocatalyst to form a catalyst bed (22). An electric heating wire is wrapped around the outer wall of the catalytic reaction tube to provide the heat required for the reaction. A gas collector (23) is provided at the top of the fixed bed reactor (21), and the outlet of the gas collector (23) is connected to the inlet of the cooling device (4).

[0014] Preferably, the cooling device (4) includes a water cooler (41) and a molecular sieve adsorption tower (42), wherein the shell-side inlet of the water cooler (41) is connected to the outlet of the gas collector (23), the shell-side outlet is connected to the inlet of the molecular sieve adsorption tower (42), and the outlet of the molecular sieve adsorption tower (42) is connected to the inlet of the hollow fiber membrane module (5); the water cooler (41) uses circulating water pipes to cool the high-temperature gas, and the molecular sieve adsorption tower (42) is used to remove residual moisture and carbon dioxide from the gas.

[0015] Preferably, the argon gas enriched on the permeate side of the hollow fiber membrane module (5) is pre-cooled by a cold box (65) and then transported to the inlet of the distillation system (6), while the nitrogen gas enriched on the permeate side is output and collected separately.

[0016] Preferably, the distillation system (6) comprises:

[0017] The low-temperature distillation column (61) has a vertical structure and is filled with high-efficiency structured packing.

[0018] The condenser evaporator (62) has its shell side integrated with the top gas phase outlet of the cryogenic distillation column (61), and its shell side liquid phase outlet returns to the cryogenic distillation column (61) via the reflux pipeline (64). The shell side gas phase outlet is connected to the inlet of the hollow fiber membrane module (5), and the tube side is connected to the liquid nitrogen refrigerant device to provide cryogenic cooling capacity.

[0019] Argon liquefaction unit (63) is a spiral wound tube heat exchanger that uses liquid nitrogen as a cold source. Its inlet is connected to the bottom outlet of the cryogenic distillation column (61), and its outlet is connected to the liquid argon storage tank (66).

[0020] Preferably, the reflux line (64) is used to return the liquid phase product from the shell side of the condenser evaporator (62) back into the cryogenic distillation column (61) to form a reflux, thereby improving the distillation efficiency.

[0021] The advantages of this application compared to existing technologies are as follows: The argon gas recovery and purification system of this application comprises an argon pretreatment module connected in series with a separator, an activated carbon adsorption tower, and a high-efficiency filter. This system can efficiently remove particulate matter, oil, hydrocarbons, dust, and other large molecular impurities, providing a clean gas source for subsequent nanocatalytic reactions and membrane separation. The multi-stage fixed-bed nanocatalytic reactor, with its composite nanocatalyst bed and electric heating wire working synergistically, can rapidly and completely convert CO and O2 into CO2 under moderate temperature and pressure. The nanoscale catalyst surface is rich in active sites, exhibiting high rates of carbon deposition and deactivation. The pressure is reduced; the combined use of screw compressors and water coolers greatly improves the energy efficiency of the compression and cooling process compared to traditional high-temperature and high-pressure processes; the hollow fiber membrane separation completes the initial separation at room temperature and pressure, reducing the distillation load; the argon-rich gas after membrane separation is pre-cooled in a cold box and enters a low-temperature distillation column, where it is combined with a liquid nitrogen refrigerant condenser-evaporator and a spiral tube liquefier to stably produce high-purity argon; the nitrogen-rich gas discharged from the distillation system is returned to the membrane module inlet for recycling, and the nitrogen obtained from the permeate side of the hollow fiber membrane can be directly collected and utilized, realizing closed-loop recovery of argon and nitrogen dual flow and greatly improving resource utilization. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an argon recovery and purification system according to an embodiment of this application.

[0023] Reference numerals: 1. Argon pretreatment module; 11. Separator; 12. Activated carbon adsorption tower; 13. Filter; 2. Nanocatalytic reaction module; 21. Fixed bed reactor; 22. Catalyst bed; 23. Gas collector; 3. Screw compressor; 4. Cooling device; 41. Water cooler; 42. Molecular sieve adsorption tower; 5. Hollow fiber membrane module; 6. Distillation system; 61. Low temperature distillation column; 62. Condenser evaporator; 63. Argon liquefaction unit; 64. Reflux pipeline; 65. Cold box; 66. Liquid argon storage tank. Detailed Implementation

[0024] To make the content of this application easier to understand, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, an argon gas recovery and purification system includes an argon gas pretreatment module 1, a nanocatalytic reaction module 2, a screw compressor 3, a hollow fiber membrane module 5, a distillation system 6, and a cooling device 4. The argon gas pretreatment module 1 includes a separator 11, an activated carbon adsorption tower 12, and a filter 13. The nanocatalytic reaction module 2 includes a fixed-bed reactor 21, a catalyst bed 22, and an electric heating wire. The cooling device 4 includes a water cooler 41 and a molecular sieve adsorption tower 42. The distillation system 6 includes a low-temperature distillation tower 61, a condenser-evaporator 62, an argon liquefaction unit 63, and a reflux pipeline 64.

[0026] The argon pretreatment module 1 consists of a separator 11, an activated carbon adsorption tower 12, and a filter 13. The recovered crude argon gas is first introduced into the inlet of separator 11, where centrifugal force is used to remove solid particles larger than 10 μm, such as metal scraps or silicon powder. The outlet of separator 11 is connected to the inlet of activated carbon adsorption tower 12, which adsorbs oil mist (lubricating oil, hydraulic oil) and hydrocarbon compounds (CH4, C2H6) from the argon gas. Subsequently, the gas from the top of the tower enters filter 13 through a connecting pipe. Filter 13 uses a 0.1 μm precision filter element to ensure that dust residue is less than 0.1 mg / m³. 3 The gas is then output to the downstream screw compressor 3, which increases the gas pressure from atmospheric pressure to 1.2 MPa to meet the requirements of subsequent catalytic reactions.

[0027] After filtration, the argon gas enters the screw compressor 3 through the outlet of filter 13. The outlet of the screw compressor 3 is connected to the inlet of the fixed-bed reactor 21. The compressed high-pressure gas flows into the fixed-bed reactor 21, which contains multiple parallel catalytic reaction tubes. Each reaction tube is filled with a composite nanocatalyst bed 22. This composite nanocatalyst is a composite material of carbon nanotubes loaded with Pt-CeO2 and molecular sieves, exhibiting high catalytic activity and selectivity. An electric heating wire is wound around the outer wall of the reaction tube, and thermocouples are arranged on the tube surface to monitor the catalyst bed temperature in real time. A PID controller adjusts the power of the electric heating wire to prevent local overheating and catalyst deactivation, thereby extending the catalyst life. The gas produced after the reaction is complete is discharged from the gas collector 23 at the top of the reactor. The gas collector 23 is located at the top of the fixed-bed reactor 21, and its outlet is connected to the shell-side inlet of the water cooler 41.

[0028] The shell-side outlet of the water cooler 41 is connected to the inlet of the molecular sieve adsorption tower 42, and the outlet of the molecular sieve adsorption tower 42 is connected to the inlet of the hollow fiber membrane module 5. The reaction gas collected at the top of the fixed-bed reactor 21 enters the shell side of the water cooler 41 through a pipeline. The tube side of the water cooler 41 is filled with circulating cooling water, which can cool the reaction gas to about 40°C, causing moisture and some CO2 to condense and precipitate. The cooled gas flows into the molecular sieve adsorption tower 42 from the shell-side outlet. The molecular sieve adsorption tower 42 is filled with type 4A molecular sieves for further removal of residual moisture and CO2, ensuring the stability of the subsequent membrane separation process.

[0029] The inlet of the hollow fiber membrane module 5 is connected to the outlet of the molecular sieve adsorption tower 42. The dehydrated and CO2-removed gas enters the inlet of the hollow fiber membrane module 5. The hollow fiber membrane module adopts a double-layer composite structure: the inner layer is a polyimide selective layer (pore size 0.5–2 nm), and the outer layer is a polysulfone support layer. It can utilize the difference in permeation rates between Ar (permeability coefficient 0.5 Barrer) and N2 (permeability coefficient 4.2 Barrer) on the membrane surface for initial enrichment. Argon is enriched on the non-permeable side (permeate side), pressurized to 0.3–0.5 MPa by the second-stage compressor, and pre-cooled to -150°C by the cold box 65 before being fed into the feed inlet in the middle of the distillation tower 61. Nitrogen enriched on the permeate side is discharged from the system or recovered for use as a circulating gas source.

[0030] The cryogenic distillation column 61 is a vertical design filled with highly efficient structured packing. Operating at -180 to -190℃ and 0.2-0.5 MPa, it utilizes the boiling point difference between argon (boiling point -185.9℃) and nitrogen (boiling point -195.8℃) for multi-stage gas-liquid mass transfer separation. A liquid distributor is installed at the feed position in the middle of the column to ensure uniform distribution of argon-rich gas. Residual nitrogen-containing gas is collected at the top of the column, and electronic-grade argon gas with a purity ≥99.999% is obtained at the bottom. The permeate side outlet of the hollow fiber membrane module 5 is connected to the middle section of the cryogenic distillation column 61 via a compressor and a cold box 65. The inlet connection is as follows: the top of the cryogenic distillation column 61 is integrated with a condenser-evaporator 62, and the gas phase outlet of the top of the cryogenic distillation column 61 is connected to the shell-side inlet of the condenser-evaporator 62. The liquid phase outlet of the shell-side of the condenser-evaporator 62 is connected to the inside of the cryogenic distillation column 61 via a reflux pipe 64. The gas phase outlet of the shell-side of the condenser-evaporator 62 is connected to the inlet of the hollow fiber membrane module 5. The tube side of the condenser-evaporator 62 is connected to an external refrigerant module and provides cryogenic cooling capacity through liquid nitrogen refrigerant. The nitrogen-containing mixed gas (containing a small amount of argon) discharged from the top of the cryogenic distillation column 61 enters the shell side of the condenser-evaporator 62 and reacts with the liquid in the tube side. Nitrogen refrigerant (-196℃) is used for heat exchange. Argon gas (boiling point -185.9℃), with a higher boiling point than nitrogen gas (boiling point -195.8℃), is preferentially condensed into liquid, forming reflux liquid, which returns to the top of the column via reflux line 64 to maintain the liquid phase reflux in the distillation column (controlling the reflux ratio to 1:3 to 1:5). The uncondensed nitrogen-rich gas (nitrogen content > 90%) is returned to the hollow fiber membrane unit 5 for recycling. The liquid nitrogen refrigerant in the tube side of the condenser evaporator 62 absorbs heat from the gas at the top of the shell side and partially vaporizes. The latent heat released during the vaporization of the liquid nitrogen refrigerant (approximately 199 kJ / kg) is transferred through heat exchange. The liquid argon (high-purity argon gas liquefied and accumulated in the column bottom) transferred to the bottom of the cryogenic distillation column 61 by the wall provides a reboiling heat source, causing some of the liquid argon to evaporate into a gas phase, forming rising vapor (maintaining the gas-liquid mass transfer power in the column); the bottom of the cryogenic distillation column 61 is integrated with an argon liquefaction unit 63, the bottom outlet of the cryogenic distillation column 61 is connected to the inlet of the argon liquefaction unit 63, and the outlet of the argon liquefaction unit 63 is connected to a liquid argon storage tank 66. The argon liquefaction unit 63 is a spiral wound tube heat exchanger and uses liquid nitrogen as a cold source to further cool the high-purity argon gas at the bottom of the column to a liquid state, realizing the final productization of electronic-grade liquid argon.

[0031] The specific process flow of the argon gas recovery and purification system in this application is as follows: First, the recovered argon gas is transported to a separator, where centrifugal force is used to remove solid particles larger than 10 μm (such as metal scraps and silicon powder). Then, it enters an activated carbon adsorption tower to adsorb oil (such as lubricating oil and hydraulic oil) and hydrocarbon compounds (such as CH4 and C4H6). Finally, it is filtered to remove 0.1 μm particles, controlling the residual dust to 0.1 mg / m³. 3The following steps yield pretreated recovered argon gas. This gas is pressurized to 1.2 MPa by a screw compressor and then enters a fixed-bed reactor. At 180–220°C, it undergoes a catalytic reaction of carbon monoxide and oxygen with a composite nanocatalyst in the internal catalyst bed to produce carbon dioxide, yielding high-temperature crude argon gas. This high-temperature crude argon gas is then cooled to 40°C in a water cooler, where some moisture and carbon dioxide are removed by condensation. It is then fed into a molecular sieve adsorption tower to further remove residual moisture and carbon dioxide, obtaining clean argon gas. Next, the clean argon gas enters a hollow fiber membrane module. Utilizing the difference in permeation rates between argon and nitrogen, argon is enriched on the permeate side, resulting in argon-rich gas with a purity of 99.5%. The nitrogen-rich gas on the permeate side is collected and output. Argon-rich gas is pressurized to 0.3–0.5 MPa by a compressor and pre-cooled to -150°C in a cold box before being fed into the middle of a cryogenic distillation column. Under operating conditions of 0.25 MPa, bottom temperature of -185°C, and top temperature of -190°C, gas-liquid mass transfer separation occurs on the surface of the structured packing. Nitrogen, due to its higher volatility, is enriched at the top of the column, while argon is enriched at the bottom. The nitrogen-containing tail gas at the top of the column enters a condenser-evaporator, where it partially condenses to form liquid at -195°C. This liquid is then returned to the top of the distillation column via a reflux pipeline for reflux. The uncondensed gas (nitrogen content > 90%) is returned to the inlet of the membrane separation module for recycling. The high-purity electronic-grade argon gas (purity ≥ 99.999%) collected at the bottom of the column is further cooled to below -186°C by an argon liquefaction unit to form liquid argon gas, which is then stored in a liquid argon storage tank.

[0032] The above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, without departing from the spirit and scope defined by the claims of this application.

Claims

1. An argon gas recovery and purification system, characterized in that, include: Argon pretreatment module (1), the inlet of which is used to introduce recycled argon to remove particulate matter, oil and hydrocarbon impurities from the recycled argon; A screw compressor (3) has its inlet connected to the outlet of the argon pretreatment module (1) to pressurize the pretreated argon. The nanocatalytic reaction module (2) has its inlet connected to the outlet of the screw compressor (3). The nanocatalytic reaction module (2) includes at least two catalytic reactors connected in series. The catalytic reactors are filled with composite nanocatalysts, which are used to react carbon monoxide and oxygen in the recovered argon gas to generate carbon dioxide through the catalytic effect of the composite nanocatalysts, so as to obtain crude argon gas. The cooling device (4) has its inlet connected to the outlet of the nanocatalytic reaction module (2) and is used to cool the crude argon gas. Hollow fiber membrane module (5), whose inlet is connected to the outlet of the cooling device (4), is used to selectively separate argon and nitrogen by permeation; A cold box (65) is used to pre-cool the argon-rich gas separated from the hollow fiber membrane module (5); The distillation system (6) has its inlet connected to the outlet of the cold box (65) and is used to distill and purify the pre-cooled argon-rich gas to electronic-grade high-purity argon gas, and to return the nitrogen-rich gas discharged from the distillation column to the inlet of the hollow fiber membrane module (5) for recycling.

2. The argon gas recovery and purification system according to claim 1, characterized in that, The argon pretreatment module (1) includes a separator (11), an activated carbon adsorption tower (12), and a filter (13) connected in series. The inlet of the separator (11) is supplied with recovered argon gas, the inlet of the activated carbon adsorption tower (12) is connected to the outlet of the separator (11), the inlet of the filter (13) is connected to the outlet of the activated carbon adsorption tower (12), and the outlet of the filter (13) is connected to the inlet of the screw compressor (3).

3. The argon gas recovery and purification system according to claim 2, characterized in that, The nanocatalytic reaction module (2) includes a fixed bed reactor (21), a catalyst bed (22), and an electric heating wire. The fixed bed reactor (21) is equipped with a catalytic reaction tube, which is filled with a composite nanocatalyst to form a catalyst bed (22). An electric heating wire is wrapped around the outer wall of the catalytic reaction tube to provide the heat required for the reaction. A gas collector (23) is provided at the top of the fixed bed reactor (21), and the outlet of the gas collector (23) is connected to the inlet of the cooling device (4).

4. The argon gas recovery and purification system according to claim 3, characterized in that, The cooling device (4) includes a water cooler (41) and a molecular sieve adsorption tower (42). The shell-side inlet of the water cooler (41) is connected to the outlet of the gas collector (23), the shell-side outlet is connected to the inlet of the molecular sieve adsorption tower (42), and the outlet of the molecular sieve adsorption tower (42) is connected to the inlet of the hollow fiber membrane module (5). The water cooler (41) uses circulating water pipes to cool the high-temperature gas, and the molecular sieve adsorption tower (42) is used to remove residual moisture and carbon dioxide from the gas.

5. The argon gas recovery and purification system according to claim 4, characterized in that, Argon gas enriched on the permeate side of the hollow fiber membrane module (5) is pre-cooled by a cold box (65) and then transported to the inlet of the distillation system (6). Nitrogen gas enriched on the permeate side is output and collected separately.

6. The argon gas recovery and purification system according to claim 5, characterized in that, The distillation system (6) includes: The low-temperature distillation column (61) has a vertical structure and is filled with high-efficiency structured packing. The condenser evaporator (62) has its shell side integrated with the top gas phase outlet of the cryogenic distillation column (61), and its shell side liquid phase outlet returns to the cryogenic distillation column (61) via the reflux pipeline (64). The shell side gas phase outlet is connected to the inlet of the hollow fiber membrane module (5), and the tube side is connected to the liquid nitrogen refrigerant device to provide cryogenic cooling capacity. Argon liquefaction unit (63) is a spiral wound tube heat exchanger that uses liquid nitrogen as a cold source. Its inlet is connected to the bottom outlet of the cryogenic distillation column (61), and its outlet is connected to the liquid argon storage tank (66).

7. An argon gas recovery and purification system according to claim 6, characterized in that, The reflux line (64) is used to return the liquid phase product from the shell side of the condenser evaporator (62) back into the cryogenic distillation column (61) to form a reflux, thereby improving the distillation efficiency.

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