Acetylene purification device and purification method

Abstract

The invention discloses an acetylene purification device and an acetylene purification method. The acetylene purification device comprises an absorption mechanism, a first desorption mechanism, a second desorption mechanism, a third desorption mechanism and an adsorption mechanism, the absorption mechanism is internally provided with an absorption cavity used for containing absorption liquid, the absorption mechanism further comprises an acetylene raw material feeding pipe and a cooler used for cooling the absorption liquid in the absorption cavity, and the gas outlet end of the acetylene raw material feeding pipe is inserted into the absorption liquid in the absorption cavity. According to the acetylene purification device disclosed by the invention, an original single desorption tower is divided into three stages of desorption mechanisms, so that not only can 4N-stage acetylene be obtained, but also impurities in the absorption liquid can be removed, the recycling times of the absorption liquid can be prolonged, and the production cost can be reduced. The purification cost is reduced and the purification efficiency is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of acetylene purification technology, specifically relating to an acetylene purification apparatus and purification method. Background Technology

[0002] Electronic-grade acetylene, as a high-purity carbon source, plays an irreplaceable role in the preparation of silicon-carbon anode materials. With the explosive growth in demand for high-energy-density batteries from fields such as new energy vehicles and consumer electronics, silicon-carbon anode materials, due to their theoretical capacity being up to 10 times that of graphite anodes, have become the core development direction for next-generation lithium-ion battery anode materials. As the global market for silicon-carbon anode materials continues to expand, the demand for electronic-grade acetylene, as its upstream core raw material, will surge accordingly.

[0003] Because acetylene is highly unstable in the liquid state and prone to decomposition reactions that can lead to container rupture or explosion, it cannot be purified using conventional distillation methods. Currently, the most common purification method combines adsorption and solvent absorption / desorption. For example, a multi-stage process using adsorption, absorption, and desorption towers effectively separates impurities from the acetylene feedstock, yielding 4N-grade electronic acetylene.

[0004] In the purification process described above, solvents are usually recycled to reduce costs. However, impurities in the acetylene feedstock, such as carbon dioxide, ethylene, ethane, C3-C5 hydrocarbons, hydrogen sulfide, and phosphine, which are easily soluble in the solvent, will dissolve in the solvent during absorption. After multiple cycles, the solvent becomes enriched through recycling, leading to an increase in the content of these impurities. Consequently, the amount of these impurities released during acetylene desorption also increases, affecting the purity of the acetylene product and preventing it from reaching the 4N purity level.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide an acetylene purification apparatus and method that can reduce the impact of excessive soluble impurities accumulating during solvent circulation on the quality of acetylene products.

[0007] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution: an acetylene purification apparatus, comprising:

[0008] An absorption mechanism is provided, which has an absorption chamber for containing an absorbent liquid. The absorption mechanism also includes an acetylene feed pipe and a cooler for cooling the absorbent liquid in the absorption chamber. The gas outlet end of the acetylene feed pipe is inserted into the absorbent liquid in the absorption chamber so that gaseous acetylene dissolves in the absorbent liquid in the absorption chamber to obtain a mixture.

[0009] The first desorption mechanism has a first desorption chamber that communicates with the absorption chamber. The first desorption chamber is used to contain the mixture delivered by the absorption mechanism. The first desorption mechanism also includes a first heater for heating the temperature of the solution in the first desorption chamber so that impurities in the mixture in the first desorption chamber are desorbed.

[0010] The second desorption mechanism has a second desorption chamber that communicates with the first desorption chamber. The second desorption chamber is used to contain the mixture delivered by the first desorption chamber. The second desorption mechanism also includes a second heater for heating the temperature of the solution in the second desorption chamber so that the acetylene in the mixture in the second desorption chamber is desorbed.

[0011] The third desorption mechanism has a third desorption chamber that communicates with the second desorption chamber. The third desorption chamber is used to contain the mixture conveyed by the second desorption chamber. The third desorption mechanism also includes a third heater for heating the temperature of the solution in the third desorption chamber so that impurities in the mixture in the third desorption chamber are desorbed. The third desorption chamber is connected to the absorption chamber so that the desorbed mixture flows to the absorption chamber.

[0012] The adsorption mechanism is connected to the second desorption chamber and is used to adsorb the absorbent liquid in the gas generated by the desorption of the second desorption chamber to obtain purified acetylene.

[0013] In one or more embodiments of the present invention, the absorption mechanism includes an inner shell and an outer shell that are nested together, the inner shell forming the absorption cavity, a cooling cavity being formed between the inner shell and the outer shell, and a cooler communicating with the cooling cavity, the cooler being used to circulate the refrigerant within the cooler and the cooling cavity.

[0014] In one or more embodiments of the present invention, the absorption mechanism further includes an exhaust pipe connected to the absorption chamber, and the exhaust pipe is provided with a valve.

[0015] In one or more embodiments of the present invention, the absorption mechanism further includes a baffle disposed within the absorption chamber, the baffle being located between the exhaust pipe and the liquid surface of the absorption liquid.

[0016] In one or more embodiments of the present invention, the absorption chamber and the first desorption chamber are connected by a pipe, the pipe being equipped with a valve and a flow meter; and / or,

[0017] The liquid level in the absorption chamber is higher than the liquid level in the first desorption chamber.

[0018] In one or more embodiments of the present invention, the first desorption mechanism further includes a first condensation chamber connected to and located above the first desorption chamber, a first condensation tube located in the first condensation chamber, and a first condenser connected to the first condensation tube. The first condensation chamber has a first exhaust port, and a valve is provided at the first exhaust port.

[0019] The second desorption mechanism further includes a second condensation chamber connected to and located above the second desorption chamber, a second condenser tube located in the second condensation chamber, and a second condenser connected to the second condenser tube. The second condensation chamber has a second exhaust port, a valve is provided at the second exhaust port, and the second exhaust port is connected to the adsorption mechanism.

[0020] The third desorption mechanism further includes a third condensation chamber connected to the third desorption chamber and located above the first desorption chamber, a third condenser tube located in the third condensation chamber, and a third condenser connected to the third condenser tube. The third condensation chamber has a third exhaust port, and a valve is provided at the third exhaust port.

[0021] In one or more embodiments of the present invention, the acetylene purification apparatus further includes:

[0022] Raw material tank, used to hold acetylene raw materials;

[0023] The pretreatment mechanism is connected between the raw material tank and the acetylene raw material feed pipe, and is used to pretreat the acetylene raw material transported by the raw material tank to adsorb moisture in the acetylene raw material.

[0024] A specific embodiment of the present invention also provides a method for purifying acetylene, using the acetylene purification apparatus as described above, the method comprising the following steps:

[0025] Acetylene feedstock is introduced into the absorbent liquid in the absorption chamber by bubbling, so that acetylene dissolves in the absorbent liquid to obtain a mixture, while removing impurities that are insoluble in the absorbent liquid. The pressure in the absorption chamber is 0.6~1MPaG, and the temperature in the absorption chamber is -50~-30℃.

[0026] The mixture is transported to the first desorption chamber for primary desorption treatment, which desorbs some of the impurities in the mixture. The temperature of the primary desorption treatment is -20~10℃ and the pressure of the primary desorption treatment is 0.4~0.8MPaG.

[0027] The mixture after the first desorption treatment is transported to the second desorption chamber for a second desorption treatment to desorb the acetylene in the mixture. The temperature of the second desorption treatment is 10~40℃ and the pressure of the second desorption treatment is 0.1~0.4MPaG.

[0028] The mixture after the secondary desorption treatment is transported to the third desorption chamber for tertiary desorption treatment to desorb impurities in the mixture. The temperature of the tertiary desorption treatment is 60~120℃, and the pressure of the secondary desorption treatment is -0.1~0.1MPaG.

[0029] The mixed gas generated during the secondary desorption process is subjected to adsorption treatment to remove the solvent from the mixed gas and obtain purified acetylene.

[0030] Specifically, the temperature inside the absorption chamber is at least 10°C lower than the temperature of the first-stage desorption treatment, and the pressure inside the absorption chamber is at least 0.1 MPaG higher than the pressure of the first-stage desorption treatment. The temperature of the second-stage desorption treatment is at least 20°C higher than the temperature of the first-stage desorption treatment, and the pressure of the second-stage desorption treatment is at least 0.1 MPaG lower than the pressure of the first-stage desorption treatment. The temperature of the third-stage desorption treatment is at least 40°C higher than the temperature of the second-stage desorption treatment, and the pressure of the third-stage desorption treatment is at least 0.1 MPaG lower than the pressure of the second-stage desorption treatment.

[0031] In one or more embodiments of the present invention, the absorbent liquid comprises a solvent, said solvent being at least one selected from acetone, N,N-dimethylformamide, N-methylpyrrolidone, propylene carbonate, and methyl acetate; and / or,

[0032] The acetylene feedstock is an acetylene feedstock that has undergone dehydration treatment.

[0033] In one or more embodiments of the present invention, the pressure inside the absorption chamber is 0.7~0.8 MPaG, and the temperature inside the absorption chamber is -40~-35℃;

[0034] The temperature of the first-stage desorption treatment is -10~0℃, and the pressure of the first-stage desorption treatment is 0.5~0.6MPaG;

[0035] The temperature of the secondary desorption treatment is 30~35℃, and the pressure of the secondary desorption treatment is 0.1~0.2MPaG;

[0036] The temperature of the third-stage desorption treatment is 80~120℃, and the pressure of the second-stage desorption treatment is -0.1~-0.05MPaG.

[0037] Compared with the prior art, the beneficial effects of the acetylene purification device of the present invention are as follows:

[0038] The original single desorption tower was divided into a three-stage desorption unit. The first desorption unit first heats up and depressurizes to remove insoluble impurities remaining in the solvent. The second desorption unit precisely controls the cooling and depressurization range, ensuring that a large number of easily soluble impurities are still retained in the solvent, while high-purity acetylene is extracted from the top of the second desorption unit. The third desorption unit further increases the desorption temperature to evaporate the easily soluble impurities in the solvent, completing the purification of the solvent. The solvent is then transported back into the absorption unit to complete the solvent circulation, effectively avoiding the impact of excessive easily soluble impurities on the quality of the acetylene product.

[0039] The acetylene feedstock is introduced into the absorbent liquid of the absorption unit by bubbling static absorption. The pressure difference is used as the power source for the liquid to flow from the absorption unit to the multi-stage desorption unit, eliminating the problems related to the conveying of moving equipment in the absorption and desorption units. At the same time, it simplifies the equipment form and improves the safety and economy of the equipment. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of an acetylene purification apparatus in an example of the present invention;

[0042] Figure 2 This is a flowchart of an acetylene purification method in an example of the present invention.

[0043] Explanation of key figure labels:

[0044] 1. Absorption mechanism; 11. Absorption chamber; 12. Acetylene feed pipe; 13. Inner shell; 131. Baffle; 132. Deflector; 14. Outer shell; 141. Refrigerant inlet; 142. Refrigerant outlet; 15. Cooling chamber; 16. Liquid inlet pipe; 17. Exhaust pipe; 2. First desorption mechanism; 21. First desorption chamber; 22. First condensation chamber; 23. First condenser tube; 24. First exhaust port; 25. First heater; 3. Second desorption mechanism; 31. Second desorption chamber; 32. Second condensation chamber; 33. Second condenser tube; 34. Second exhaust port; 35. Second heater; 4. Third desorption mechanism; 41. Third desorption chamber; 42. Third condensation chamber; 43. Third condenser tube; 44. Third exhaust port; 45. Third heater; 46. Drive pump; 5. Adsorption mechanism. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0046] As described in the background section, existing acetylene purification devices typically employ a multi-stage process combining adsorption, absorption, and desorption towers to effectively separate impurities from the acetylene feedstock, thereby obtaining 4N-grade electronic-grade acetylene. In the absorption tower, the solvent absorbs acetylene and some impurities from the acetylene feedstock at low temperatures. Then, the solvent containing the absorbed acetylene and other substances is transferred to the desorption tower. The desorption process in the desorption tower is generally carried out under heating conditions, thereby desorbing the acetylene from the solution to obtain the 4N-grade electronic-grade acetylene product.

[0047] However, in existing purification equipment, the solvent is recycled during the purification process to reduce costs. Since impurities in the acetylene feedstock are also soluble in the solvent, and some impurities are also desorbed during the acetylene desorption process in the desorption tower, some impurities remain in the solvent. After multiple solvent cycles, impurities accumulate, leading to an increase in the amount of impurities desorbed during the acetylene desorption process in the desorption tower. This results in the acetylene product purity not reaching the 4N level. At this point, the solvent must be replaced, which not only affects the purification efficiency but also increases the purification cost.

[0048] Furthermore, during the absorption-desorption process, auxiliary equipment is typically required to power the solvent and complete the cycle of entering, spraying, and exiting the tower. Due to the highly reactive, flammable, and explosive nature of acetylene, pressure resistance and explosion-proof features must be considered when selecting auxiliary equipment. In addition, the complexity of high- and low-temperature operating conditions generally necessitates absorption at low temperatures followed by desorption at high temperatures, requiring high temperature resistance from the materials in contact with the pump body and the material. This makes it difficult to select such auxiliary equipment, thus placing higher demands on some components of the purification unit and increasing costs.

[0049] To address the aforementioned problems, the acetylene purification device of the present invention divides the original single desorption tower into a three-stage desorption mechanism. The first desorption mechanism performs a first stage of heating and depressurization to remove insoluble impurities remaining in the solvent. The second desorption mechanism precisely controls the cooling and depressurization range, ensuring that a large number of readily soluble impurities are still retained in the solvent while high-purity acetylene is extracted from the top of the second desorption mechanism. The third desorption mechanism further increases the desorption temperature to evaporate readily soluble impurities in the solvent, completing the purification of the solvent. The solvent is then returned to the absorption mechanism to complete the solvent circulation, effectively avoiding the impact of excessive readily soluble impurities on the quality of the acetylene product.

[0050] In addition, this purification device uses a static bubbling absorption method to introduce acetylene feedstock into the absorption mechanism, and uses the pressure difference as the power source for the liquid to flow from the absorption mechanism to the multi-stage desorption mechanism, eliminating the related problems of moving equipment transportation in the absorption and desorption mechanisms; at the same time, it simplifies the equipment form and improves the safety and economy of the equipment.

[0051] like Figure 1 As shown, the acetylene purification device in this example includes an absorption mechanism 1, a first desorption mechanism 2, a second desorption mechanism 3, a third desorption mechanism 4, and an adsorption mechanism 5.

[0052] The absorption mechanism 1 has an absorption chamber 11 for containing the absorbent liquid. The absorption mechanism 1 also includes an acetylene feed pipe 12 and a cooler for cooling the absorbent liquid in the absorption chamber 11. The gas outlet end of the acetylene feed pipe 12 is inserted into the absorbent liquid in the absorption chamber 11 so that the gaseous acetylene dissolves in the absorbent liquid in the absorption chamber 11 to obtain a mixture.

[0053] The cooler is designed to lower the temperature of the absorbent liquid within the absorption chamber 11, thereby reducing the kinetic energy of the solvent molecules and making it easier for acetylene molecules to be captured. This improves the dissolution efficiency of the absorbent liquid and reduces system pressure, maximizing the dissolution of acetylene in the absorbent liquid. The cooler used is a commercially available type.

[0054] Specifically, the absorption mechanism 1 includes an inner shell 13 and an outer shell 14 nested together. The inner shell 13 encloses the absorption cavity 11, and a cooling cavity 15 is located between the inner shell 13 and the outer shell 14. The cooler is connected to the cooling cavity 15 and is used to circulate the refrigerant within the cooler and the cooling cavity 15. The refrigerant can be a commercially available refrigerant, which can be selected according to the required cooling temperature. The outer shell 14 is provided with a refrigerant inlet 141 and a refrigerant outlet 142.

[0055] Furthermore, the absorption mechanism 1 also includes a liquid inlet pipe 16 connected to the absorption chamber 11, and a partition 131 disposed on the inner wall of the inner shell 13. The partition 131 can divide the absorption chamber 11 into three sequentially connected chambers, namely... Figure 1 The device comprises three chambers: left, middle, and right. The liquid inlet pipe 16 is inserted to the bottom of the left chamber, and the outlet end of the acetylene feed pipe 12 is inserted to the bottom of the middle chamber. The bottom of the right chamber is connected to the first desorption chamber 21 of the first desorption mechanism 2 via a pipe. The absorbent enters the left chamber through the liquid inlet pipe, then flows to the middle chamber, and finally flows to the first desorption chamber 21 through the right chamber. This arrangement promotes the circulation of the absorbent and maximizes contact between the absorbent and the acetylene feed discharged from the outlet end of the acetylene feed pipe 12, thereby absorbing the acetylene.

[0056] The absorption mechanism 1 also includes an exhaust pipe 17 connected to the absorption chamber 11, and the exhaust pipe 17 is equipped with a valve. Because some substances in the acetylene raw material are insoluble in the absorption liquid, and some substances such as acetylene that are soluble in the absorption liquid may not be absorbed by the absorption liquid in time, the exhaust pipe 17 is used to discharge the above-mentioned gases, and the valve controls the amount of gas discharged, which can also control the pressure inside the absorption chamber 11.

[0057] In this example, the absorption mechanism 1 also includes a baffle 132 disposed in the absorption chamber 11. The baffle 132 is located between the exhaust pipe 17 and the liquid surface of the absorbent. This arrangement is to prevent the gas discharged from the acetylene feed pipe 12 from bursting and causing the absorbent to splash onto the exhaust pipe 17, thus blocking the exhaust pipe 17.

[0058] The first desorption mechanism 2 has a first desorption chamber 21 connected to the absorption chamber 11. The first desorption mechanism 2 also includes a first condensation chamber 22 connected to and located above the first desorption chamber 21, a first condenser tube 23 located in the first condensation chamber 22, and a first condenser connected to the first condenser tube 23. The first desorption chamber 21 is used to contain the mixture delivered by the absorption mechanism 1. The first desorption mechanism 2 also includes a first heater 25 for heating the solution temperature in the first desorption chamber 21 so that impurities in the mixture in the first desorption chamber 21 are desorbed. The first condensation chamber 22 has a first exhaust port 24, and a valve is provided at the first exhaust port 24.

[0059] It is understood that the solution in the first desorption chamber 21 is the mixture supplied to the first desorption chamber 21 by the absorption mechanism 1, which contains the absorbent, impurities dissolved in the absorbent, and acetylene. Therefore, the first desorption mechanism 2 heats the solution in the first desorption chamber 21 and makes the gas pressure in the first desorption chamber 21 lower than the gas pressure in the absorption chamber 11, thereby allowing some impurities in the mixture to be discharged. The first desorption mechanism 2 is mainly used to remove light component impurities from the mixture, such as hydrogen, oxygen, argon, nitrogen, nitrous oxide, carbon monoxide, methane, etc.

[0060] In addition, the first condenser allows the refrigerant to flow in the first condenser tube 23, mainly to condense and reflux the absorbent, reducing waste of the absorbent. The first exhaust port 24 can discharge the desorbed gas, and the valve at the first exhaust port 24 controls and regulates the gas pressure in the first desorption chamber 21 by controlling the amount of gas discharged.

[0061] The absorption chamber 11 and the first desorption chamber 21 are connected by a pipe. The pipe is equipped with a valve and a flow meter. The flow rate of liquid from the absorption chamber 11 to the first desorption chamber 21 can be controlled and obtained by the cooperation of the valve and the flow meter.

[0062] Preferably, the liquid level in the absorption chamber 11 is higher than the liquid level in the first desorption chamber 21. This arrangement, utilizing the principle of communicating vessels, helps to drive the liquid in the absorption chamber 11 to flow into the first desorption chamber 21.

[0063] The second desorption mechanism 3 has a second desorption chamber 31 connected to the first desorption chamber 21. The second desorption mechanism 3 also includes a second condensation chamber 32 connected to and located above the second desorption chamber 31, a second condenser tube 33 located in the second condensation chamber 32, and a second condenser connected to the second condenser tube 33. The second desorption chamber 31 is used to contain the mixture delivered by the first desorption chamber 21. The second desorption mechanism 3 also includes a second heater 35 for heating the solution temperature in the second desorption chamber 31 so that the acetylene in the mixture in the second desorption chamber 31 is desorbed. The second condensation chamber 32 has a second exhaust port 34, and a valve is provided at the second exhaust port 34. The second exhaust port 34 is connected to the adsorption mechanism 5.

[0064] It is understandable that the second desorption mechanism 3 further heats the mixture in the second desorption chamber 31 and makes the gas pressure in the second desorption chamber 31 lower than the gas pressure in the first desorption chamber 21, thereby enabling the acetylene in the mixture to be desorbed and discharged.

[0065] Additionally, the second condenser allows the refrigerant to flow within the second condenser tube 33, primarily to condense and reflux the absorbent vapor, reducing absorbent waste. The gas discharged from the second exhaust port 34 contains a small amount of absorbent vapor in addition to acetylene; therefore, the adsorption mechanism 5 is needed to remove the absorbent vapor from the gas, thus obtaining 4N-level acetylene gas. The second exhaust port 34 can discharge the desorbed gas, and the valve at the second exhaust port 34 controls the gas discharge rate, thereby controlling and regulating the gas pressure within the second desorption chamber 31.

[0066] The adsorption mechanism 5 is connected to the second desorption chamber 31 and is used to adsorb the absorbent liquid in the gas generated by desorption in the second desorption chamber 31 to obtain purified acetylene. The adsorption mechanism 5 is a solvent adsorption column used to adsorb residual solvent in the product. The solvent adsorption column is a common adsorption column on the market.

[0067] In other examples, the adsorption mechanism 5 can also adsorb impurities in the gas generated by the desorption of the second desorption chamber 31.

[0068] The first desorption chamber 21 and the second desorption chamber 31 are connected by a pipe. The pipe is equipped with a valve, which can control the flow rate of liquid from the first desorption chamber 21 to the second desorption chamber 31.

[0069] The third desorption mechanism 4 has a third desorption chamber 41 connected to the second desorption chamber 31. The third desorption mechanism 4 also includes a third condensation chamber 42 connected to the third desorption chamber 41 and located above the first desorption chamber 21, a third condenser tube 43 located in the third condensation chamber 42, and a third condenser connected to the third condenser tube 43. The third desorption chamber 41 is used to contain the mixture transported by the second desorption chamber 31. The third desorption mechanism 4 also includes a third heater 45 for heating the solution temperature in the third desorption chamber 41 to desorb impurities in the mixture in the third desorption chamber 41. The third desorption chamber 41 is connected to the absorption chamber 11 so that the desorbed mixture flows to the absorption chamber 11. The third condensation chamber 42 has a third exhaust port 44, and a valve is provided at the third exhaust port 44.

[0070] Understandably, the third desorption mechanism 4 further heats the mixture in the third desorption chamber 41 and makes the gas pressure in the third desorption chamber 41 lower than the gas pressure in the second desorption chamber 31, thereby desorbing and discharging the remaining impurities in the mixture. These impurities are mainly heavy component impurities, such as carbon dioxide, ethylene, ethane, C3~C5 hydrocarbons, hydrogen sulfide, and phosphine.

[0071] Preferably, the third desorption chamber 41 can be connected to the acetylene feed pipe 12 through a pipe, and a drive pump 46 can be installed on the pipe connecting the third desorption chamber 41 and the acetylene feed pipe 12 to facilitate the recycling of the absorbent liquid.

[0072] In addition, the third condenser allows the refrigerant to flow in the third condenser tube 43, mainly to condense and reflux the absorbent vapor, reducing the waste of absorbent. The third exhaust port 44 is used to discharge desorbed gas impurities. The valve at the third exhaust port 44 controls the amount of gas discharged, thereby controlling and regulating the gas pressure in the third desorption chamber 41.

[0073] It should be noted that the first heater 25, the second heater 35, and the third heater 45 can be commercially available heating tubes or heating rods, respectively inserted into the corresponding first desorption chamber 21, second desorption chamber 31, and third desorption chamber 41, thereby heating the liquid inside each chamber. Understandably, the surface of the heating tube or heating rod can be coated with a common protective layer to prevent the material of the heating tube or heating rod from contaminating the liquid in the first desorption chamber 21, second desorption chamber 31, and third desorption chamber 41 or reacting with the liquid in these chambers. The protective layer can be made of common materials.

[0074] The absorption mechanism 1, the first desorption mechanism 2, the second desorption mechanism 3, the third desorption mechanism 4, and the adsorption mechanism 5 can be connected to each other through pipes.

[0075] The acetylene purification device also includes a raw material tank, a pretreatment mechanism, a compressor, and a product tank. The raw material tank is used to hold the acetylene raw material. The pretreatment mechanism is connected between the raw material tank and the acetylene raw material inlet pipe 12, and is used to pretreat the acetylene raw material transported by the raw material tank to adsorb moisture from the acetylene raw material. The pretreatment mechanism is a pretreatment mechanism in existing acetylene purification processes, such as an adsorption column filled with dehydrating molecular sieves or adsorbents, as long as it can remove moisture from the acetylene raw material. The compressor is connected to the product tank and the adsorption mechanism 5, and is used to adsorb residual solvents in the product. The acetylene gas treated by the adsorption mechanism 5 is compressed into the product tank.

[0076] like Figure 2 As shown, a specific example of the present invention also provides a method for purifying acetylene, using the acetylene purification apparatus as described above, the method comprising the following steps:

[0077] S1. Acetylene feedstock is introduced into the absorbent liquid in the absorption chamber by bubbling, so that acetylene dissolves in the absorbent liquid to obtain a mixture, while removing impurities that are insoluble in the absorbent liquid. The pressure in the absorption chamber is 0.6~1MPaG, and the temperature in the absorption chamber is -40~-30℃.

[0078] S2. The mixture is transported to the first desorption chamber for primary desorption treatment, so that some impurities in the mixture are desorbed. The temperature of the primary desorption treatment is -20~10℃ and the pressure of the primary desorption treatment is 0.4~0.8MPaG.

[0079] S3. The mixture after the first-stage desorption treatment is transported to the second desorption chamber for a second-stage desorption treatment to desorb the acetylene in the mixture. The temperature of the second-stage desorption treatment is 10~40℃ and the pressure of the second-stage desorption treatment is 0.1~0.4MPaG.

[0080] S4. The mixture after the secondary desorption treatment is transported to the third desorption chamber for tertiary desorption treatment to desorb impurities in the mixture. The temperature of the tertiary desorption treatment is 60~120℃, and the pressure of the secondary desorption treatment is -0.1~0.1MPaG.

[0081] S5. The mixed gas generated during the secondary desorption process is subjected to adsorption treatment to remove the solvent from the mixed gas and obtain purified acetylene.

[0082] Specifically, the temperature inside the absorption chamber is at least 10°C lower than the temperature of the first-stage desorption treatment, and the pressure inside the absorption chamber is at least 0.1 MPaG higher than the pressure of the first-stage desorption treatment. The temperature of the second-stage desorption treatment is at least 20°C higher than the temperature of the first-stage desorption treatment, and the pressure of the second-stage desorption treatment is at least 0.1 MPaG lower than the pressure of the first-stage desorption treatment. The temperature of the third-stage desorption treatment is at least 40°C higher than the temperature of the second-stage desorption treatment, and the pressure of the third-stage desorption treatment is at least 0.1 MPaG lower than the pressure of the second-stage desorption treatment.

[0083] The exhaust ports of the absorption chamber, the first desorption chamber, the second desorption chamber, and the third desorption chamber can be connected to a vacuum pump (such as a vacuum pump) so that the pressure in the absorption chamber, the pressure of the first-stage desorption process, the pressure of the second-stage desorption process, and the pressure of the third-stage desorption process are all less than atmospheric pressure.

[0084] It is understood that during the acetylene purification process, the absorbent is circulated sequentially within the absorption chamber, the first desorption chamber, the second desorption chamber, and the third desorption chamber, and the acetylene feedstock continuously enters the absorption chamber; that is, purified acetylene is continuously obtained in step S5. The purification method of this invention can extend the number of times the absorbent can be recycled and continuously produce 4N-grade acetylene.

[0085] In this example, the absorbent includes a solvent, which is at least one selected from acetone, N,N-dimethylformamide, N-methylpyrrolidone, propylene carbonate, and methyl acetate. The solute may be hydroquinone (a commonly used polymerization inhibitor for acetylene). In other examples, the absorbent may contain only a solvent, or the absorbent may contain other solutes.

[0086] Preferably, the acetylene feedstock can be a dehydrated acetylene feedstock, and the moisture content of the dehydrated acetylene feedstock can be controlled to be <0.1ppm.

[0087] Preferably, the pressure inside the absorption chamber is 0.7~0.8 MPaG, and the temperature inside the absorption chamber is -40~-35℃. The higher the absorption pressure and the lower the temperature, the greater the ability to absorb acetylene and the higher the solvent loading efficiency. During desorption, the proportion of the main acetylene component is high, and the relative concentration of impurities can be reduced. However, excessively high feed pressure places higher demands on the raw material booster, and lower temperatures result in higher energy consumption. The preferred range here is based on a comprehensive consideration of product quality and energy consumption.

[0088] Preferably, the temperature of the first-stage desorption treatment is -10 to 0°C, and the pressure of the first-stage desorption treatment is 0.5 to 0.6 MPaG. Since the first-stage desorption is to remove light components that are difficult to dissolve in the solvent, theoretically, the higher the desorption temperature and the lower the pressure at this stage, the more light components will be removed. However, this will also lead to the precipitation of a large amount of acetylene and a lower yield. The preferred range here is based on a comprehensive consideration of product purity and yield.

[0089] Preferably, the temperature of the secondary desorption treatment is 30~35℃, and the pressure of the secondary desorption treatment is 0.1~0.2MPaG. The purpose of this stage is to desorb acetylene products. Theoretically, the higher the temperature and the lower the pressure, the more products are desorbed and the higher the yield. However, excessively high temperature and excessively low pressure will cause heavy component impurities that are easily soluble in the solvent to be desorbed, affecting the purity of the product. The preferred range here is based on a comprehensive consideration of product purity and yield.

[0090] Preferably, the temperature of the three-stage desorption treatment is 80~120℃, and the pressure of the three-stage desorption treatment is -0.1~-0.05MPaG. The purpose of this stage is to regenerate the solvent and remove the easily soluble heavy component impurities accumulated in it. Theoretically, the higher the temperature and the lower the pressure, the better the solvent regeneration effect, but the higher the energy consumption; the preferred range here is based on a comprehensive consideration of product quality and energy consumption.

[0091] Specifically, the outlet flow rate (desorbed gas discharge rate) in the first-stage desorption treatment is 10~50 L / min, preferably 30~40 L / min. The outlet flow rate (desorbed gas discharge rate) in the second-stage desorption treatment is 80~400 L / min, preferably 200~350 L / min. The outlet flow rate (desorbed gas discharge rate) in the tertiary desorption treatment is 10~50 L / min, preferably 30~40 L / min.

[0092] Specifically, the flow rate of the mixture supplied from the absorption chamber to the first desorption chamber is 3~20 L / min, preferably 5~15 L / min. The inlet flow rate of the acetylene feedstock in the absorption chamber is 100~500 L / min, preferably 300~400 L / min.

[0093] It should be noted that the acetylene raw material in the acetylene purification device and purification method of the present invention can be 2N industrial grade acetylene, that is, the present invention can purify 2N industrial grade acetylene to 4N electronic grade acetylene.

[0094] The following will describe in detail the acetylene purification apparatus and purification method of the present invention with reference to specific embodiments and comparative examples.

[0095] Example 1

[0096] Building such Figure 1 The apparatus shown is for purifying acetylene.

[0097] The feed gas flow rate in the absorption chamber is 400 L / min, and the temperature in the absorption chamber is -30℃. The absorbent used in the absorption vessel is a DMF solution containing 0.1 wt% hydroquinone, and the feed flow rate of the absorbent is 8 L / min. The gas pressure in the absorption chamber is controlled to 1 MPaG by controlling the valve on the exhaust pipe.

[0098] The temperature of the first heater is controlled at -10℃, the gas pressure in the first desorption chamber is controlled at 0.6MPaG through the valve at the first exhaust port, and the temperature of the first condenser is controlled at -30℃.

[0099] The temperature of the second heater is controlled at 40℃, the gas pressure in the second desorption chamber is controlled at 0.4MPaG through the valve at the second exhaust port, and the temperature of the second condenser is -30℃.

[0100] The temperature of the third heater is controlled at 100℃, the gas pressure in the third desorption chamber is controlled at 0.1 MPaG through the valve at the third exhaust port, and the temperature of the third condenser is -30℃. The solution discharged from the third desorption mechanism is returned to the absorption chamber to achieve the recycling of the absorbent liquid.

[0101] The gas discharged from the second exhaust port is collected by the adsorption mechanism and is purified acetylene.

[0102] Example 2

[0103] Building such Figure 1 The apparatus shown is for purifying acetylene.

[0104] The feed gas flow rate in the absorption chamber is 300 L / min, and the temperature in the absorption chamber is -40℃. The absorbent used in the absorption vessel is a DMF solution containing 0.1 wt% hydroquinone, and the feed flow rate of the absorbent is 5 L / min. The gas pressure in the absorption chamber is controlled to be 0.6 MPaG by controlling the valve on the exhaust pipe.

[0105] The temperature of the first heater is controlled at 10℃, the gas pressure in the first desorption chamber is controlled at 0.4MPaG through the valve at the first exhaust port, and the temperature of the first condenser is -30℃.

[0106] The temperature of the second heater is controlled at 30°C, the gas pressure in the second desorption chamber is controlled at 0.2 MPaG through the valve at the second exhaust port, and the temperature of the second condenser is -30°C.

[0107] The temperature of the third heater is controlled at 120℃, and the gas pressure in the third desorption chamber is controlled at -0.05MPaG through the valve at the third exhaust port. The temperature of the third condenser is -30℃. The solution discharged from the third desorption mechanism is returned to the absorption chamber to achieve the recycling of the absorbent.

[0108] The gas discharged from the second exhaust port is collected by the adsorption mechanism and is purified acetylene.

[0109] Example 3

[0110] Building such Figure 1 The apparatus shown is for purifying acetylene.

[0111] The feed gas flow rate in the absorption chamber is 500 L / min, and the temperature in the absorption chamber is -40℃. The absorbent used in the absorption vessel is a DMF solution containing 0.1 wt% hydroquinone, and the feed flow rate of the absorbent is 5 L / min. The gas pressure in the absorption chamber is controlled to 1 MPaG by controlling the valve on the exhaust pipe.

[0112] The temperature of the first heater is controlled at 0℃, the gas pressure in the first desorption chamber is controlled at 0.8MPaG through the valve at the first exhaust port, and the temperature of the first condenser is -30℃.

[0113] The temperature of the second heater is controlled at 30°C, the gas pressure in the second desorption chamber is controlled at 0.4 MPaG through the valve at the second exhaust port, and the temperature of the second condenser is -30°C.

[0114] The temperature of the third heater is controlled at 120℃, and the gas pressure in the third desorption chamber is controlled at 0 MPaG through the valve at the third exhaust port. The temperature of the third condenser is -30℃. The solution discharged from the third desorption mechanism is returned to the absorption chamber to achieve the recycling of the absorbent liquid.

[0115] The gas discharged from the second exhaust port is collected by the adsorption mechanism and is purified acetylene.

[0116] Example 4

[0117] Building such Figure 1 The apparatus shown is for purifying acetylene.

[0118] The feed gas flow rate in the absorption chamber is 400 L / min, and the temperature in the absorption chamber is -30℃. The absorbent used in the absorption vessel is a DMF solution containing 0.1 wt% hydroquinone, and the feed flow rate of the absorbent is 8 L / min. The gas pressure in the absorption chamber is controlled to be 0.8 MPaG by controlling the valve on the exhaust pipe.

[0119] The temperature of the first heater is controlled at -20℃, the gas pressure in the first desorption chamber is controlled at 0.4MPaG through the valve at the first exhaust port, and the temperature of the first condenser is controlled at -30℃.

[0120] The temperature of the second heater is controlled at 10℃, the gas pressure in the second desorption chamber is controlled at 0.1MPaG through the valve at the second exhaust port, and the temperature of the second condenser is -30℃.

[0121] The temperature of the third heater is controlled at 60℃, and the gas pressure in the third desorption chamber is controlled at -0.1 MPaG through the valve at the third exhaust port. The temperature of the third condenser is -30℃. The solution discharged from the third desorption mechanism is returned to the absorption chamber to achieve the recycling of the absorbent.

[0122] The gas discharged from the second exhaust port is collected by the adsorption mechanism and is purified acetylene.

[0123] Comparative Example 1

[0124] The purification device is basically the same as the purification device in Example 1, except that there is no first desorption mechanism, that is, the absorption mechanism is directly connected to the second desorption mechanism.

[0125] The feed gas flow rate in the absorption chamber is 400 L / min, and the temperature in the absorption chamber is -30℃. The absorbent used in the absorption vessel is a DMF solution containing 0.1 wt% hydroquinone, and the feed flow rate of the absorbent is 8 L / min. The gas pressure in the absorption chamber is controlled to 1 MPaG by controlling the valve on the exhaust pipe.

[0126] The temperature of the second heater is controlled at 40℃, the gas pressure in the second desorption chamber is controlled at 0.4MPaG through the valve at the second exhaust port, and the temperature of the second condenser is -30℃.

[0127] The temperature of the third heater is controlled at 100℃, the gas pressure in the third desorption chamber is controlled at 0.1 MPaG through the valve at the third exhaust port, and the temperature of the third condenser is -30℃. The solution discharged from the third desorption mechanism is returned to the absorption chamber to achieve the recycling of the absorbent liquid.

[0128] The gas discharged from the second exhaust port is collected by the adsorption mechanism and is purified acetylene.

[0129] Comparative Example 2

[0130] The purification device is basically the same as the purification device in Example 2. The only difference is that there is no third desorption mechanism. That is, the solution discharged by the second desorption mechanism is returned to the absorption chamber to realize the recycling of the absorption liquid.

[0131] The feed gas flow rate in the absorption chamber is 300 L / min, and the temperature in the absorption chamber is -30℃. The absorbent used in the absorption vessel is a DMF solution containing 0.1 wt% hydroquinone, and the feed flow rate of the absorbent is 5 L / min. The gas pressure in the absorption chamber is controlled to be 0.6 MPaG by controlling the valve on the exhaust pipe.

[0132] The temperature of the first heater is controlled at 10℃, the gas pressure in the first desorption chamber is controlled at 0.4MPaG through the valve at the first exhaust port, and the temperature of the first condenser is -30℃.

[0133] The temperature of the second heater is controlled at 30°C, the gas pressure in the second desorption chamber is controlled at 0.2 MPaG through the valve at the second exhaust port, and the temperature of the second condenser is -30°C.

[0134] The gas discharged from the second exhaust port is collected by the adsorption mechanism and is purified acetylene.

[0135] After the absorbent was cycled 10, 20 and 50 times, the gas discharged from the second exhaust port in Examples 1 to 4 and Comparative Examples 1 and 2 was collected and the gas after passing through the adsorption mechanism was analyzed. The data are shown in Table 1 and Table 2 below (the data in Table 1 and Table 2 are the results of the same product analysis. They are divided into Table 1 and Table 2 only because one table is not enough).

[0136] Table 1

[0137]

[0138] Table 2

[0139]

[0140] The data in the table above shows that the acetylene purification device and method of the present invention can still obtain acetylene with a purity of over 99.99% after multiple cycles, especially after 50 cycles. It should also be noted that the number of cycles in the above tests refers to 10, 20, and 50 cycles of the absorbent liquid. During the circulation of the absorbent liquid, the raw gas is continuously fed into the purification device, and the purified acetylene is continuously obtained.

[0141] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0142] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for purifying acetylene, characterized by include: An absorption mechanism is provided, which has an absorption chamber for containing an absorbent liquid. The absorption mechanism also includes an acetylene feed pipe and a cooler for cooling the absorbent liquid in the absorption chamber. The gas outlet end of the acetylene feed pipe is inserted into the absorbent liquid in the absorption chamber so that gaseous acetylene dissolves in the absorbent liquid in the absorption chamber to obtain a mixture. The first desorption mechanism has a first desorption chamber that communicates with the absorption chamber. The first desorption chamber is used to contain the mixture delivered by the absorption mechanism. The first desorption mechanism also includes a first heater for heating the temperature of the solution in the first desorption chamber so that impurities in the mixture in the first desorption chamber are desorbed. The second desorption mechanism has a second desorption chamber that communicates with the first desorption chamber. The second desorption chamber is used to contain the mixture delivered by the first desorption chamber. The second desorption mechanism also includes a second heater for heating the temperature of the solution in the second desorption chamber so that the acetylene in the mixture in the second desorption chamber is desorbed. The third desorption mechanism has a third desorption chamber that communicates with the second desorption chamber. The third desorption chamber is used to contain the mixture conveyed by the second desorption chamber. The third desorption mechanism also includes a third heater for heating the temperature of the solution in the third desorption chamber so that impurities in the mixture in the third desorption chamber are desorbed. The third desorption chamber is connected to the absorption chamber so that the desorbed mixture flows to the absorption chamber. The adsorption mechanism is connected to the second desorption chamber and is used to adsorb the absorbent liquid in the gas generated by the desorption of the second desorption chamber to obtain purified acetylene.

2. The purification device of acetylene according to claim 1, characterized by, The absorption mechanism includes an inner shell and an outer shell that are nested together. The inner shell forms the absorption cavity, and the space between the inner shell and the outer shell is a cooling cavity. The cooler is connected to the cooling cavity and is used to circulate the refrigerant within the cooler and the cooling cavity.

3. The purification device of acetylene according to claim 1, characterized by, The absorption mechanism also includes an exhaust pipe connected to the absorption chamber, and the exhaust pipe is equipped with a valve.

4. The purification device of acetylene according to claim 3, characterized by The absorption mechanism also includes a baffle disposed in the absorption chamber, the baffle being located between the exhaust pipe and the liquid surface of the absorption liquid.

5. The purification device of acetylene according to claim 1, characterized by, The absorption chamber and the first desorption chamber are connected by a pipe equipped with a valve and a flow meter; and / or, The liquid level in the absorption chamber is higher than the liquid level in the first desorption chamber.

6. The purification apparatus of acetylene according to claim 1, characterized by The first desorption mechanism further includes a first condensation chamber connected to and located above the first desorption chamber, a first condenser tube located in the first condensation chamber, and a first condenser connected to the first condenser tube. The first condensation chamber has a first exhaust port, and a valve is provided at the first exhaust port. The second desorption mechanism further includes a second condensation chamber connected to and located above the second desorption chamber, a second condenser tube located in the second condensation chamber, and a second condenser connected to the second condenser tube. The second condensation chamber has a second exhaust port, a valve is provided at the second exhaust port, and the second exhaust port is connected to the adsorption mechanism. The third desorption mechanism further includes a third condensation chamber connected to the third desorption chamber and located above the first desorption chamber, a third condenser tube located in the third condensation chamber, and a third condenser connected to the third condenser tube. The third condensation chamber has a third exhaust port, and a valve is provided at the third exhaust port.

7. The purification device of acetylene according to claim 1, characterized by The acetylene purification apparatus further includes: Raw material tank, used to hold acetylene raw materials; The pretreatment mechanism is connected between the raw material tank and the acetylene raw material feed pipe, and is used to pretreat the acetylene raw material transported by the raw material tank to adsorb moisture in the acetylene raw material.

8. A method for purifying acetylene, using the acetylene purification apparatus as described in any one of claims 1 to 7, characterized in that, The purification method for acetylene includes the following steps: Acetylene feedstock is introduced into the absorbent liquid in the absorption chamber by bubbling, so that acetylene dissolves in the absorbent liquid to obtain a mixture, while removing impurities that are insoluble in the absorbent liquid. The pressure in the absorption chamber is 0.6~1MPaG, and the temperature in the absorption chamber is -50~-30℃. The mixture is transported to the first desorption chamber for primary desorption treatment, which desorbs some of the impurities in the mixture. The temperature of the primary desorption treatment is -20~10℃ and the pressure of the primary desorption treatment is 0.4~0.8MPaG. The mixture after the first desorption treatment is transported to the second desorption chamber for a second desorption treatment to desorb the acetylene in the mixture. The temperature of the second desorption treatment is 10~40℃ and the pressure of the second desorption treatment is 0.1~0.4MPaG. The mixture after the secondary desorption treatment is transported to the third desorption chamber for tertiary desorption treatment to desorb impurities in the mixture. The temperature of the tertiary desorption treatment is 60~120℃, and the pressure of the secondary desorption treatment is -0.1~0.1MPaG. The mixed gas generated during the secondary desorption process is subjected to adsorption treatment to remove the solvent from the mixed gas and obtain purified acetylene. Specifically, the temperature inside the absorption chamber is at least 10°C lower than the temperature of the first-stage desorption treatment, and the pressure inside the absorption chamber is at least 0.1 MPaG higher than the pressure of the first-stage desorption treatment. The temperature of the second-stage desorption treatment is at least 20°C higher than the temperature of the first-stage desorption treatment, and the pressure of the second-stage desorption treatment is at least 0.1 MPaG lower than the pressure of the first-stage desorption treatment. The temperature of the third-stage desorption treatment is at least 40°C higher than the temperature of the second-stage desorption treatment, and the pressure of the third-stage desorption treatment is at least 0.1 MPaG lower than the pressure of the second-stage desorption treatment.

9. The method for purifying acetylene according to claim 8, characterized in that, The absorbent includes a solvent, which is at least one selected from acetone, N,N-dimethylformamide, N-methylpyrrolidone, propylene carbonate, and methyl acetate; and / or, The acetylene feedstock is an acetylene feedstock that has undergone dehydration treatment.

10. The method for purifying acetylene according to claim 8, characterized in that, The pressure inside the absorption chamber is 0.7~0.8 MPaG, and the temperature inside the absorption chamber is -40~-35℃; The temperature of the first-stage desorption treatment is -10~0℃, and the pressure of the first-stage desorption treatment is 0.5~0.6MPaG; The temperature of the secondary desorption treatment is 30~35℃, and the pressure of the secondary desorption treatment is 0.1~0.2MPaG; The temperature of the third-stage desorption treatment is 80~120℃, and the pressure of the second-stage desorption treatment is -0.1~-0.05MPaG.

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