An acetylene purification system

Abstract

This utility model discloses an acetylene purification system. The inlet of a cryogenic condenser is connected to the acetylene feed gas; the outlet of the cryogenic condenser is connected to the inlet of a pre-dehydration generator; the outlet of the pre-dehydration generator is connected to the inlet of a deep dehydration generator; the outlet of the deep dehydration generator is connected to the inlet of a deoxygenator; the outlet of the deoxygenator is connected to the inlet of a primary dephosphorizer; the outlet of the primary dephosphorizer is connected to the inlet of the deep dephosphorizer; the outlet of the deep dephosphorizer is connected to the inlet of an absorption tower; the bottom outlet of the absorption tower is connected to the top inlet of a desorption tower; the bottom outlet of the desorption tower is connected to the top inlet of the absorption tower; and the top outlet of the desorption tower is connected to an acetylene collector. This utility model provides an acetylene purification system capable of deeply removing phosphine and arsine to the ppb level, and simultaneously deoxygenating and dehydrating acetylene gas in an integrated pretreatment system, ensuring that the purity of the acetylene gas can reach above 7N.

Description

Technical Field

[0001] This utility model relates to the field of acetylene purification technology, and in particular to an acetylene purification system. Background Technology

[0002] In the fluidized bed production process of silicon-carbon anode materials, acetylene gas is a key carbon source, and its purity directly determines the electrochemical performance and interfacial consistency of the silicon-carbon composite material. Currently, even with strict control of operating procedures, it is still impossible to completely eliminate production accidents. The internal cause of these accidents lies in the properties of the substances themselves. For example, if the source is acetylene produced via the calcium carbide process, it may contain trace amounts of phosphine and arsine. Phosphine, in particular, has an auto-ignition temperature of 100–150°C; crude PH3 containing P2H4 can spontaneously ignite upon contact with air at room temperature, which is the core trigger for phosphine explosions. Its explosion limits (volume fraction in air) range from 1.8% to 98%, a very wide explosion range. Even a small leak poses an explosion risk. Its flash point is -88°C, and its combustion products are P2O5 and H2O. Under oxygen-deficient conditions, it can even precipitate elemental yellow phosphorus, further increasing the difficulty of emergency response.

[0003] Therefore, before acetylene gas enters the fluidized bed reactor, it is crucial to thoroughly remove flammable impurities such as phosphine and arsine, and maximize the purity of acetylene. This is a key prerequisite for fundamentally reducing the risk of reactor combustion and explosion and ensuring the safety of large-scale production. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the existing technology, this utility model provides an acetylene purification system with good operational safety. It is an integrated acetylene gas pretreatment system that can deeply remove phosphine and arsine to the ppb level and simultaneously deoxygenate and dehydrate acetylene gas, ensuring that the purity of acetylene gas can reach above 7N. It has important engineering application value for improving the safety and product consistency of large-scale production.

[0005] To achieve the above objectives, the embodiments of this utility model adopt the following technical solutions: An acetylene purification system includes a cryogenic condenser, a pre-dehydration generator, a deep dehydration generator, a deoxygenator, a primary dephosphorizer, a deep dephosphorizer, an absorption tower, and a desorption tower connected in sequence. The inlet of the cryogenic condenser is connected to the acetylene feed gas. The outlet of the cryogenic condenser is connected to the inlet of the pre-dehydration generator. The outlet of the pre-dehydration generator is connected to the inlet of the deep dehydration generator. The outlet of the deep dehydration generator is connected to the inlet of the deoxygenator. The outlet of the deoxygenator is connected to the inlet of the primary dephosphorizer. The outlet of the primary dephosphorizer is connected to the inlet of the deep dephosphorizer. The outlet of the deep dephosphorizer is connected to the inlet of the absorption tower. The bottom outlet of the absorption tower is connected to the top inlet of the desorption tower. The bottom outlet of the desorption tower is connected to the top inlet of the absorption tower. The top outlet of the desorption tower is connected to an acetylene collector.

[0006] According to one aspect of the present invention, the bottom of the desorption tower is connected to a desorption reboiler, the top of the desorption tower is connected to a desorption cooler, and the outlet of the desorption tower is connected to an acetylene collector through the desorption cooler.

[0007] According to one aspect of this utility model, a lean-rich liquid heat exchanger is provided between the absorption tower and the desorption tower.

[0008] According to one aspect of the present invention, the bottom outlet of the absorption tower and the top inlet of the desorption tower are connected in sequence by a rich liquid pump and a lean-rich liquid heat exchanger, and the bottom outlet of the desorption tower and the top inlet of the absorption tower are connected in sequence by a lean liquid pump and a lean-rich liquid heat exchanger.

[0009] According to one aspect of the present invention, a fixed bed is provided inside the pre-dehydration generator, and the fixed bed is filled with a 13X type molecular sieve membrane.

[0010] According to one aspect of the present invention, a fixed bed is provided inside the deep dehydration generator, and the fixed bed is filled with a type 3A molecular sieve.

[0011] According to one aspect of the present invention, the deoxidizer is filled with a solid adsorbent, which is a manganese-based deoxidizer.

[0012] According to one aspect of this utility model, the primary dephosphorizer is filled with a copper-zinc dephosphorizing agent.

[0013] According to one aspect of the present invention, the deep dephosphorizer is filled with a silver alumina dephosphorizing agent.

[0014] According to one aspect of the present invention, the top inlet of the absorption tower is connected to an absorption solvent pipe, and the absorption solvent in the absorption tower is NMP, DMF, DMSO, acetone or cyclohexanone.

[0015] Advantages of this invention: An acetylene purification system includes a pre-dehydration generator, a deep dehydration generator, a deoxygenator, a primary dephosphorizer, a deep dephosphorizer, an absorption tower, and a desorption tower connected in sequence. The acetylene gas passes through the pre-dehydration generator, which removes water content to approximately 120 ppm. After passing through the deep dehydration generator, the water content is further reduced to 0.1 ppm, ensuring reliability. The dehydrated acetylene gas passes through the deoxygenator, reducing the oxygen content to <10 ppb. The dehydrated and deoxygenated acetylene gas then passes through the primary dephosphorizer, reducing the phosphorus content to below 100 ppb. After passing through the deep dephosphorizer, the phosphorus content is further reduced to 0.1 ppb. Finally, the absorption tower and desorption tower ensure that the acetylene gas purity reaches above 7N. Therefore, using this acetylene purification system, multiple methods can be used to process bottled acetylene gas or pipeline-transported industrial acetylene gas. It offers high stability, achieving an acetylene gas purity of 7N electronic grade, suitable for applications in silicon-carbon coating reactions and the semiconductor industry. The acetylene purification system described above not only has good socio-economic benefits, but also good market economic benefits. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of an acetylene purification system according to the present invention.

[0018] Figure 1 The components are: 1. Acetylene container; 2. Cryogenic condenser; 3. Pre-dehydration generator; 4. Deep dehydration generator; 5. Deoxygenator; 6. Primary dephosphorizer; 7. Deep dephosphorizer; 8. Absorption tower; 9. Rich liquor pump; 10. Lean and rich liquor heat exchanger; 11. Lean liquor pump; 12. Desorption tower; 13. Desorption reboiler; 14. Desorption cooler. Detailed Implementation

[0019] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1

[0023] like Figure 1 As shown, an acetylene purification system includes a cryogenic condenser 2, a pre-dehydration generator 3, a deep dehydration generator 4, a deoxygenator 5, a primary dephosphorizer 6, a deep dephosphorizer 7, an absorption tower 8, and a desorption tower 12 connected in sequence. The inlet of the cryogenic condenser 2 is connected to the gas supply outlet of the acetylene container 1, the outlet of the cryogenic condenser 2 is connected to the top inlet of the pre-dehydration generator 3, and the bottom outlet of the pre-dehydration generator 3 is connected to the bottom inlet of the deep dehydration generator 4. The deep dehydration generator 4... The top outlet of the deoxidizer 5 is connected to the top inlet of the deoxidizer 5, the bottom outlet of the deoxidizer 5 is connected to the top inlet of the primary dephosphorizer 6, the bottom outlet of the primary dephosphorizer 6 is connected to the top inlet of the deep dephosphorizer 7, the bottom outlet of the deep dephosphorizer 7 is connected to the inlet of the absorption tower 8, the bottom outlet of the absorption tower 8 is connected to the top inlet of the desorption tower 12, the bottom outlet of the desorption tower 12 is connected to the top inlet of the absorption tower 8, and the top outlet of the desorption tower 12 is connected to the acetylene collector.

[0024] In practical applications, the bottom of the desorption tower 12 is connected to a desorption reboiler 13, which provides the necessary heat for the desorption process, promoting the desorption and separation of acetylene in the absorbent. The top of the desorption tower 12 is connected to a desorption cooler 14, which cools the acetylene desorbed from the top outlet of the desorption tower 12, facilitating subsequent collection and transportation.

[0025] In practical applications, a lean-rich liquid heat exchanger 10 is installed between the absorption tower and the desorption tower. The bottom outlet of the absorption tower 8 and the top inlet of the desorption tower 12 are connected in sequence by a rich liquid pump 9 and a lean-rich liquid heat exchanger 10, and the bottom outlet of the desorption tower 12 and the top inlet of the absorption tower 8 are connected in sequence by a lean liquid pump 11 and a lean-rich liquid heat exchanger 10.

[0026] In practical applications, a fixed bed is provided inside the pre-dehydration generator 3, and the fixed bed is filled with 13X molecular sieves with a particle diameter of 3.5 to 4.5 mm.

[0027] In practical applications, the deep dehydration generator 4 is equipped with a fixed bed, which is filled with 3A type molecular sieves with a particle diameter of 3.1 to 3.3 mm.

[0028] In practical applications, the deoxidizer 5 is filled with a solid adsorbent, which is a manganese-based deoxidizer, specifically a MnO / Al2O3 supported deoxidizer.

[0029] In practical applications, the primary dephosphorizer 6 is filled with a copper-zinc dephosphorizing agent. The deep dephosphorizer 7 is filled with a silver-loaded alumina dephosphorizing agent. Because phosphine and arsine have similar chemical properties, arsenic is removed along with phosphorus.

[0030] In practical applications, the top inlet of the absorption tower 8 is connected to an absorption solvent pipeline. The absorption solvent in the absorption tower is NMP, DMF, DMSO, acetone, or cyclohexanone. Preferably, the absorption solvent is NMP, which has a high boiling point and low volatility at normal pressure, preventing gaseous phase escape into the acetylene gas during regeneration and thus affecting the purity of the acetylene gas.

[0031] In practical applications, the refrigerant in the cryogenic condenser 2 is a cryogenic medium such as liquid ammonia or liquid nitrogen, which causes the free water and water vapor in the acetylene gas to condense and remove the free water from the acetylene gas.

[0032] The method for purifying acetylene using the aforementioned acetylene purification system includes the following steps: 1. The acetylene gas output from the gas outlet of the acetylene container is reduced to 0.12 MPa and then introduced into the cryogenic condenser. In the cryogenic condenser, the free water and water vapor in the acetylene gas are condensed and the acetylene gas is cooled to -18°C. The acetylene gas flow rate does not exceed 8 m / s. 2. After passing through the cryogenic cooler, the acetylene gas enters the pre-dehydration generator, where the water content in the acetylene gas is removed to 120 ppm. The pre-dehydrated acetylene gas then enters the deep dehydration generator, where the water content in the acetylene gas is removed to 0.08 ppm. The pressure drop of the acetylene gas after passing through the pre-dehydration generator and the deep dehydration generator is stably maintained within the range of 5 kPa. 3. The dehydrated acetylene gas enters the deoxygenator for deoxygenation. Inside the deoxygenator, the oxygen content of the acetylene gas is reduced to 8 ppb, and the pressure drop of the acetylene gas after flowing through the deoxygenator is stably maintained within the range of 5 kPa. 4. After dehydration and deoxygenation, the phosphorus content of the acetylene gas enters the primary dephosphorizer and is reduced to 80 ppb. After passing through the deep dephosphorizer, it is reduced to 0.1 ppb. The pressure drop of the acetylene gas after passing through the primary dephosphorizer and the deep dephosphorizer is stably maintained within the range of 5 kPa. 5. After dehydration, deoxygenation, and dephosphorization, the acetylene gas enters the absorption tower. Inside the absorption tower, the absorption solvent is sprayed from top to bottom. The absorption tower is filled with high-efficiency packing material. The acetylene gas undergoes mass transfer with the solvent in the packing layer from bottom to top. The acetylene gas dissolves in the absorption solvent and is carried out of the absorption tower by the rich liquid pump. It then exchanges heat with the lean liquid from the desorption tower bottom in the lean-rich liquid heat exchanger before entering the desorption tower. A heat source is input to the desorption tower bottom to maintain the bottom operating temperature at 95℃ and the top operating temperature at 80℃. After exiting the top of the desorption tower, the acetylene gas is cooled by a desorption cooler before exiting the system, yielding 7N electronic-grade acetylene gas. The gas composition of the acetylene feed gas and the 7N electronic-grade acetylene gas in the acetylene container is shown in Table 1 below.

[0033] Table 1

[0034] Example 2

[0035] An acetylene purification system includes a cryogenic condenser, a pre-dehydration generator, a deep dehydration generator, a deoxygenator, a primary dephosphorizer, a deep dephosphorizer, an absorption tower, and a desorption tower connected in sequence. The inlet of the cryogenic condenser is connected to an acetylene feed gas pipeline. The outlet of the cryogenic condenser is connected to the top inlet of the pre-dehydration generator. The bottom outlet of the pre-dehydration generator is connected to the bottom inlet of the deep dehydration generator. The top outlet of the deep dehydration generator is connected to the top inlet of the deoxygenator. The bottom outlet of the deoxygenator is connected to the top inlet of the primary dephosphorizer. The bottom outlet of the primary dephosphorizer is connected to the top inlet of the deep dephosphorizer. The bottom outlet of the deep dephosphorizer is connected to the inlet of the absorption tower. The bottom outlet of the absorption tower is connected to the top inlet of the desorption tower. The bottom outlet of the desorption tower is connected to the top inlet of the absorption tower. The top outlet of the desorption tower is connected to an acetylene collector.

[0036] In practical applications, the pressure of acetylene gas source transported in the acetylene feedstock gas pipeline should not exceed 0.15 MPa to prevent excessive pressure or pipeline vibration from causing acetylene self-polymerization and exothermic explosion.

[0037] In practical applications, a desorption reboiler is connected to the bottom of the desorption tower. The desorption reboiler provides the necessary heat for the desorption process, promoting the desorption and separation of acetylene from the absorbent. A desorption cooler is connected to the top of the desorption tower, which cools the acetylene desorbed from the top outlet of the tower, facilitating subsequent collection and transportation.

[0038] In practical applications, a rich-lean liquid heat exchanger is installed between the absorption tower and the desorption tower. The bottom outlet of the absorption tower and the top inlet of the desorption tower are connected in sequence via a rich liquid pump and a rich-lean liquid heat exchanger, and the bottom outlet of the desorption tower and the top inlet of the absorption tower are connected in sequence via a lean liquid pump and a rich-lean liquid heat exchanger.

[0039] In practical applications, a fixed bed is installed inside the pre-dehydration generator, and the fixed bed is filled with 13X molecular sieves with a particle diameter of 3.5 to 4.5 mm.

[0040] In practical applications, the deep dehydration generator is equipped with a fixed bed, which is filled with 3A type molecular sieves with a particle diameter of 3.1 to 3.3 mm.

[0041] In practical applications, the deoxidizer is filled with a solid adsorbent, which is a manganese-based deoxidizer, specifically a MnO / Al2O3 supported deoxidizer.

[0042] In practical applications, the primary dephosphorizer is filled with a copper-zinc dephosphorizing agent. The deep dephosphorizer is filled with a silver-loaded alumina dephosphorizing agent. Because phosphine and arsine have similar chemical properties, arsenic is removed along with phosphorus.

[0043] In practical applications, the absorption tower is connected to an absorption solvent pipeline at its top inlet. The absorption solvent in the absorption tower is NMP, DMF, DMSO, acetone, or cyclohexanone. Preferably, the absorption solvent is NMP, which has a high boiling point and low volatility at normal pressure, preventing gaseous phase escape into the acetylene gas during regeneration and thus affecting the purity of the acetylene gas.

[0044] In practical applications, the refrigerant in the cryogenic condenser is a cryogenic medium such as liquid ammonia or liquid nitrogen, which causes the free water and water vapor in the acetylene gas to condense and remove the free water from the acetylene gas.

[0045] The method for purifying acetylene using the aforementioned acetylene purification system includes the following steps: 1. After controlling the pressure of the acetylene gas source in the acetylene raw material gas pipeline outside the boundary area to 0.13 MPa, it is introduced into the cryogenic condenser to condense the free water and water vapor in the acetylene. The acetylene gas is cooled to -25℃ in the cryogenic condenser, and the acetylene gas flow rate is 6 m / s. 2. After passing through the cryogenic cooler, the acetylene gas enters the pre-dehydration generator, where the water content in the acetylene gas is removed to 120 ppm. The pre-dehydrated acetylene gas then enters the deep dehydration generator, where the water content in the acetylene gas is removed to 0.07 ppm. The pressure drop of the acetylene gas after passing through the pre-dehydration generator and the deep dehydration generator is stably maintained within the range of 8 kPa. 3. The dehydrated acetylene gas enters the deoxygenator for deoxygenation, so that the oxygen content of the acetylene gas is <10ppb, and the pressure drop of the acetylene gas after flowing through the deoxygenator is stably maintained within the range of 8kPa. 4. After the acetylene gas is dehydrated and deoxygenated, the phosphorus content is reduced to 75 ppb after entering the primary dephosphorizer, and then reduced to 0.1 ppb after flowing through the deep dephosphorizer. The pressure drop of the acetylene gas after flowing through the primary dephosphorizer and the deep dephosphorizer is stably maintained within the range of 8 kPa. 5. After dehydration, deoxygenation, and dephosphorization, the acetylene gas enters the absorption tower. Inside the tower, the absorption solvent is sprayed from top to bottom. The absorption tower is filled with high-efficiency packing material. The acetylene gas undergoes mass transfer with the solvent in the packing layer from bottom to top. The acetylene gas dissolves in the absorption solvent and is carried out of the absorption tower by the rich liquid pump. It then exchanges heat with the lean liquid from the desorption tower bottom in the lean-rich liquid heat exchanger before entering the desorption tower. A heat source is input to the desorption tower bottom to maintain the bottom operating temperature at 110℃ and the top operating temperature at 90℃. After exiting the top of the desorption tower, the acetylene gas is cooled by a desorption cooler before exiting the system, yielding 7N electronic-grade acetylene gas. The gas composition of the acetylene feed gas and the 7N electronic-grade acetylene gas is shown in Table 2 below.

[0046] Table 2

[0047] Advantages of this invention: An acetylene purification system includes a pre-dehydration generator, a deep dehydration generator, a deoxygenator, a primary dephosphorizer, a deep dephosphorizer, an absorption tower, and a desorption tower connected in sequence. The acetylene gas passes through the pre-dehydration generator, which removes water content to approximately 120 ppm. After passing through the deep dehydration generator, the water content is further reduced to 0.1 ppm, ensuring reliability. The dehydrated acetylene gas passes through the deoxygenator, reducing the oxygen content to <10 ppb. The dehydrated and deoxygenated acetylene gas then passes through the primary dephosphorizer, reducing the phosphorus content to below 100 ppb. After passing through the deep dephosphorizer, the phosphorus content is further reduced to 0.1 ppb. Finally, the absorption tower and desorption tower ensure that the acetylene gas purity reaches above 7N. Therefore, using this acetylene purification system, multiple methods can be used to process bottled acetylene gas or pipeline-transported industrial acetylene gas. It offers high stability, achieving an acetylene gas purity of 7N electronic grade, suitable for applications in silicon-carbon coating reactions and the semiconductor industry. The acetylene purification system described above not only has good socio-economic benefits, but also good market economic benefits.

[0048] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An acetylene purification system characterized by, The system comprises, in sequence, a cryogenic condenser, a pre-dehydration generator, a deep dehydration generator, a deoxygenator, a primary dephosphorizer, a deep dephosphorizer, an absorption tower, and a desorption tower. The inlet of the cryogenic condenser is connected to acetylene feed gas. The outlet of the cryogenic condenser is connected to the inlet of the pre-dehydration generator. The outlet of the pre-dehydration generator is connected to the inlet of the deep dehydration generator. The outlet of the deep dehydration generator is connected to the inlet of the deoxygenator. The outlet of the deoxygenator is connected to the inlet of the primary dephosphorizer. The outlet of the primary dephosphorizer is connected to the inlet of the deep dephosphorizer. The outlet of the deep dephosphorizer is connected to the inlet of the absorption tower. The bottom outlet of the absorption tower is connected to the top inlet of the desorption tower. The bottom outlet of the desorption tower is connected to the top inlet of the absorption tower. The top outlet of the desorption tower is connected to an acetylene collector.

2. An acetylene purification system according to claim 1, wherein The bottom of the desorption tower is connected to a desorption reboiler, the top of the desorption tower is connected to a desorption cooler, and the outlet of the desorption tower is connected to an acetylene collector through the desorption cooler.

3. The acetylene purification system of claim 1, wherein, A lean and rich liquid heat exchanger is installed between the absorption tower and the desorption tower.

4. The acetylene purification system according to claim 3, characterized in that, The bottom outlet of the absorption tower and the top inlet of the desorption tower are connected in sequence via a rich liquid pump and a lean-rich liquid heat exchanger, and the bottom outlet of the desorption tower and the top inlet of the absorption tower are connected in sequence via a lean liquid pump and a lean-rich liquid heat exchanger.

5. The acetylene purification system according to claim 1, characterized in that, The pre-dehydration generator is equipped with a fixed bed, which is filled with a 13X type molecular sieve membrane.

6. The acetylene purification system of claim 1, wherein, The deep dehydration generator is equipped with a fixed bed, which is filled with 3A type molecular sieve.

7. The acetylene purification system of claim 1, wherein, The deoxidizer is filled with a solid adsorbent, which is a manganese-based deoxidizer.

8. The acetylene purification system of claim 1, wherein, The primary dephosphorizer is filled with copper-zinc dephosphorizing agent.

9. The acetylene purification system of claim 1, wherein The deep dephosphorizer is filled with silver-alumina dephosphorizing agent.

10. The acetylene purification system of claim 1, wherein, The absorption tower is connected to an absorption solvent pipeline at its top inlet. The absorption solvent is NMP, DMF, DMSO, acetone, or cyclohexanone.

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