An ethylene complex absorbent, its preparation method and application
By using a new ionic liquid absorber containing rare earth metal ionic liquid, using chemical complexing and hydrogen bonding, the problems of low separation yield, low purity and high cost in the prior art are solved, and efficient and reversible ethylene absorption and separation effects are achieved.
Patent Information
- Application Number
- CN202211153728.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-21
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2042-09-21
AI Technical Summary
The prior art has problems of low yield, low purity and high cost when separating and recovering ethylene and ethane, especially in the separation of ethylene and ethane in the dry gas of the refinery, which is difficult to achieve efficient and low-cost separation.
A new ionic liquid absorber containing rare earth metal ion liquid is used to achieve high-efficiency and reversible absorption of ethylene through the chemical complexation of rare earth metal ions and olefins, as well as the hydrogen bond between cations, chloride ions and ethylene.
It realizes high-efficiency reversible absorption of ethylene, improves the yield and purity of ethylene, reduces energy consumption and carbon emissions, and has a simple synthesis method and is suitable for industrial production.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of gas separation, and relates to an ethylene absorbent and its preparation method and application, in particular to an ethylene absorbent containing rare earth metal ionic liquid and its preparation method and application. Background Art
[0002] Ethylene, as a basic raw material, is one of the basic chemical raw materials with the largest production and consumption in the world and plays a crucial role in the petrochemical industry. So far, domestic ethylene production processes are mainly divided into petroleum routes and non-petroleum routes. The petroleum routes are mainly tubular furnace steam cracking, naphtha catalytic cracking, and heavy oil catalytic cracking; the non-petroleum routes are mainly ethane cracking, coal (methanol) to olefins, acetylene hydrogenation, and syngas to ethylene and other technologies. However, in the process of olefin production, the off-gases such as refinery dry gas are rich in a large amount of light hydrocarbons such as ethane and propane, so it is impossible to directly obtain high-purity ethylene products. The amount of ethylene in the dry gas generated by the catalytic cracking unit is quite considerable. Directly using it as fuel gas causes great waste of resources and the large amount of carbon dioxide generated seriously pollutes the environment. Therefore, extracting ethylene from catalytic cracking dry gas is an effective way to reduce waste and increase ethylene production, which can greatly improve resource utilization rate, reduce production costs, and increase economic benefits. The separation of ethylene and ethane in refinery dry gas is the most difficult and an urgent problem to be solved for obtaining high-purity ethylene resources. Therefore, it is of great significance to develop low-cost and high-efficiency ethylene recovery technology.
[0003] The main existing methods for separating and recovering ethylene and ethane are traditional low-temperature distillation method, membrane separation method, absorption separation method, and adsorption separation method. Among them, the low-temperature distillation method requires very low operating temperatures (-90°C to -120°C) and relatively high operating pressures (0.5 to 0.6 MPa), so it has disadvantages such as high cost and high energy consumption. Although the membrane separation technology has low cost and low energy consumption, the difficulty lies in how to select a suitable membrane material to achieve both high selectivity and high flux at the same time, and the thermal stability of the membrane material needs to be improved. Compared with traditional technologies, the adsorption separation method has simple equipment and good energy-saving effect, but in actual industrial production applications, the ethylene recovery rate is low (about 90%) and the product purity is low (>70%). The complexation absorption separation method separates two different substances by the different solubilities of each component in the mixture in the absorbent, which is a typical gas-liquid mass transfer process.
[0004] The complex absorption separation method is mainly divided into physical absorption and chemical absorption. Physical absorption mainly realizes separation by the different dissolution abilities of different components in the absorbent. In industry, there is mainly the oil absorption method, etc. Due to reasons such as large loss of absorbent in the process, there are also problems of low ethylene yield (85%) and low product purity (90%). Chemical absorption utilizes the chemical property differences between olefins and alkanes. The electron-rich structure of olefins undergoes π-bond complexation reactions with functional groups or transition metals, while alkanes do not have electron-rich structures and cannot form bonds with olefin molecules. Thus, an olefin / alkane separation absorbent with high solubility and good selectivity can be designed to achieve efficient separation of olefins. Due to the use of the room-temperature chemical complexation between the absorbent and olefins, the operating conditions are mild. The chemical absorption method can greatly reduce energy consumption and carbon emissions, and has a high ethylene recovery rate. Therefore, high ethylene absorption capacity, good stability, simple synthesis method, and good ethylene recycling performance are the keys to the design and synthesis of the absorbent.
[0005] As a new type of solvent with cationic and anionic structures, ionic liquids are a very promising ethylene absorbent due to their unique advantages such as low vapor pressure, low volatility, good stability, strong gas dissolution ability, and structural designability. Currently, the ionic liquids used for separating and recovering ethylene and ethane mainly include conventional ionic liquids, functionalized ionic liquids, and ionic liquids containing transition metals. Conventional ionic liquids have a certain separation effect on olefins / alkanes, but the selectivity is concentrated at 2 - 3, which cannot meet the requirements of industrialization. Some functional groups (such as cyano, amide, hydroxyl, etc.) interact with olefins, which can improve the selectivity of ionic liquids for olefins. However, due to the weak interaction, the solubility of olefins in ionic liquids decreases. Transition metals can achieve specific complexation with olefins, which has a more obvious improvement on the performance of ionic liquids. Their solubility is mainly affected by the types and structures of ionic liquid cations, anion ligands, and the electron-donating and electron-accepting abilities of transition metals. Among them, the ionic liquid systems containing Cu(I) and Ag(I) have attracted much attention. Since Cu(I) and Ag(I) metal ions have the (n - 1)d 10 s 0 electron configuration, they are both easy to accept electrons with the outermost s empty orbit and easy to give out excessive d orbital electrons. Therefore, they are easy to undergo π-complexation reactions with olefins, increasing the dissolution amount and separation selectivity of olefins. However, the above-mentioned ionic liquids have problems such as high cost and easy deactivation of the absorbent. Summary of the Invention
[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an ethylene absorbent, its preparation method and application, especially to provide an ethylene absorbent containing rare earth metal ionic liquid, its preparation method and application.
[0007] To achieve the purpose of this invention, the present invention adopts the following technical solutions:
[0008] In a first aspect, the present invention provides an ethylene complexing absorbent, which comprises a rare earth metal-containing ionic liquid having the structure shown in Formula I (hereinafter abbreviated as [P 666,14 x [RECl y )
[0009]
[0010] wherein RE is a rare earth element and y = x + 3.
[0011] In order to improve the solubility of ethylene in the ionic liquid and the stability of the absorbent, considering the high solubility of long-chain quaternary phosphonium salts and metal chlorides in ethylene, and the special 4f electron configuration of rare earth metal ions which are prone to be electron donors and acceptors, the present invention combines the ionic liquid with rare earth metal chlorides to propose a new ionic liquid absorbent composed of trihexyltetradecylphosphonium chloride cations and rare earth metal chloride anions. By utilizing the chemical complexation between rare earth metal ions and olefins, as well as the hydrogen bond interaction between cations, chloride ions and ethylene, etc., the efficient and reversible absorption of ethylene is achieved together. The ethylene complexing absorbent involved in the present invention has the characteristics of good stability, simple synthesis method and convenient use, and is suitable for application in the absorption and recovery of ethylene, providing a new idea for the separation and recovery of ethylene and ethane in dry gas.
[0012] In the present invention, the rare earth element is selected from Y, Nd, Gd, Dy, Er, Ce, Pr, Eu, Sc, Sm, La, Pm, Tb, Ho, Tm, Yb or Lu.
[0013] In a second aspect, the present invention provides a preparation method of the ethylene complexing absorbent according to the first aspect, and the preparation method comprises:
[0014] Mixing trihexyltetradecylphosphonium chloride and rare earth chloride hexahydrate in an organic solvent for reaction, and removing the organic solvent to obtain the product.
[0015] The synthesis method of the ethylene complexing absorbent involved in the present invention is simple and very suitable for large-scale industrial production, providing a new idea for the separation and recovery of ethylene and ethane in dry gas.
[0016] Preferably, the molar ratio of trihexyltetradecylphosphonium chloride to rare earth chloride hexahydrate is (2 - 5):1, such as 2:1, 3:1, 4:1, 5:1, etc. Other specific point values within this numerical range can be selected and will not be elaborated one by one here.
[0017] When the molar ratio of the trihexyltetradecylphosphonium chloride salt to the rare earth chloride hexahydrate is specifically selected to be (2-5):1, the rare earth ionic liquid can obtain a smaller viscosity and a larger gas diffusion rate, and has a better effect on gas absorption; if the amount of trihexyltetradecylphosphonium chloride salt is further increased, it will lead to a decrease in the metal concentration in the ionic liquid and a poor effect on gas absorption; if the amount of trihexyltetradecylphosphonium chloride salt is further decreased, it will lead to an increase in the viscosity of the ionic liquid, which is not conducive to gas absorption.
[0018] Preferably, the organic solvent includes any one or a combination of at least two of ethanol, methanol, acetonitrile, ether, n-hexane, chloroform, dimethylformamide, acetone, pyridine or cyclohexane.
[0019] Preferably, the temperature of the reaction is 15-40 °C, such as 15 °C, 18 °C, 20 °C, 22 °C, 25 °C, 28 °C, 30 °C, 32 °C, 35 °C, 38 °C, 40 °C, etc.; the reaction time is 5-48 h, such as 5 h, 10 h, 15 h, 20 h, 25 h, 30 h, 42 h, 48 h, etc. Other specific point values within the above numerical ranges can be selected and will not be elaborated one by one here.
[0020] Since the absorbent involved in the present invention has a room-temperature chemical complexation effect with olefins, the operating conditions are mild, which can greatly reduce energy consumption and carbon emissions.
[0021] Preferably, the removal of the organic solvent includes rotary evaporation treatment followed by vacuum drying treatment.
[0022] In a third aspect, the present invention provides the use of the ethylene complexing absorbent according to the first aspect or the preparation method according to the second aspect in the separation and treatment of ethylene and ethane.
[0023] In a fourth aspect, the present invention provides the use of the ethylene complexing absorbent according to the first aspect or the preparation method according to the second aspect in the absorption, separation and recovery of ethylene.
[0024] Preferably, the temperature of the absorption treatment is 25-50 °C, such as 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, etc.; the pressure of the absorption treatment is 0.1-1 MPa, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1 MPa, etc. Other specific point values within the above numerical ranges can be selected and will not be elaborated one by one here.
[0025] Preferably, the temperature of the desorption treatment is 120 - 180 °C, such as 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, etc.; the pressure of the desorption treatment is 0 - 0.1 MPa, such as 0 MPa, 0.02 MPa, 0.03 MPa, 0.04 MPa, 0.05 MPa, 0.06 MPa, 0.07 MPa, 0.08 MPa, 0.09 MPa, 0.1 MPa, etc. Other specific point values within the above numerical ranges can be selected and will not be elaborated one by one here.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] The present invention combines ionic liquids with rare earth metal chlorides and proposes a novel ionic liquid absorbent composed of trihexyltetradecylphosphonium chloride cations and rare earth metal chloride anions. By utilizing the chemical complexation between rare earth metal ions and olefins, as well as the hydrogen bond interaction between cations, chloride ions and ethylene, etc., the efficient and reversible absorption of ethylene is jointly achieved. The ethylene complexation absorbent involved in the present invention has the characteristics of good stability, simple synthesis method and convenient use, and is suitable for the absorption and recovery of ethylene, providing a new idea for the separation and recovery of ethylene and ethane in dry gas. Specific Embodiments
[0028] To further elaborate on the technical means and effects adopted by the present invention, the following further illustrates the technical solutions of the present invention in combination with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.
[0029] The trihexyltetradecylphosphonium chloride (P 666,14 Cl) involved in the following embodiments is purchased from Shanghai Macklin Biochemical Technology Co., Ltd., with the model number MKL-T864952;
[0030] The yttrium chloride hexahydrate (YCl3·6H2O), neodymium chloride hexahydrate (NdCl3·6H2O), gadolinium chloride hexahydrate (GdCl3·6H2O), dysprosium chloride hexahydrate (DyCl3·6H2O), erbium chloride hexahydrate (ErCl3·6H2O), lanthanum chloride hexahydrate (LaCl3·6H2O), cerium chloride hexahydrate (CeCl3·6H2O), and holmium chloride hexahydrate (HoCl3·6H2O) involved in the following embodiments are all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.
[0031] The measurement method of the decomposition temperature in the following examples is as follows: Using a TGA Q5000 instrument, in a nitrogen atmosphere, with a heating rate of 10 K / min and a temperature interval of 10 K, the TGA curve of the ionic liquid in the temperature range from room temperature to 973.15 K was measured. Generally, the temperature at which the mass of the substance is lost by 5% is defined as the thermal decomposition temperature of the substance.
[0032] The measurement method of the water content in the following examples is as follows: The water content of the dried ionic liquid at room temperature was measured using a Karl Fischer moisture meter.
[0033] The measurement method of the ethylene absorption capacity in the following examples is as follows: An in-house built gas-liquid phase equilibrium device was used to evaluate the ethylene absorption performance of the ionic liquid. An equal amount of the ionic liquid was weighed and placed in the water bath of the absorption kettle for magnetic stirring. By recording the changes in the pressure readings on the absorption kettle and the gas buffer tank at the initial and equilibrium states, the ethylene absorption capacity in each ionic liquid was calculated using the PR equation of state.
[0034] Example 1
[0035] Take 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of yttrium(III) chloride hexahydrate (YCl3·6H2O) and dissolve them in absolute ethanol. Stir at 25 °C for 18 h. After the reaction is completed, use a rotary evaporator to remove the solvent at 60 °C, and then dry the obtained product under vacuum at 80 °C for 12 h to obtain a colorless transparent viscous liquid [P 666,14 3[YCl6].
[0036] The above viscous liquid was characterized, and its decomposition temperature was measured to be 560.14 K, the water content was <20 ppm. At 30 °C, each mole of [P 666,14 3[YCl6] ionic liquid absorbed 0.049 mol of ethylene. At 120 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 96%, and the ethylene absorption capacity of the ionic liquid after 5-stage desorption was completely restored.
[0037] Example 2
[0038] Take 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of neodymium(III) chloride hexahydrate (NdCl3·6H2O) and dissolve them in absolute ethanol. Stir at 30 °C for 12 h. After the reaction is completed, use a rotary evaporator to remove the solvent at 60 °C, and then dry the obtained product under vacuum at 80 °C for 12 h to obtain a viscous liquid [P 666,14 3[NdCl6].
[0039] The above viscous liquid was characterized, and its decomposition temperature was measured to be 512.70 K, with a water content of <20 ppm. At 30 °C, each mole of [P 666,14 3[NdCl6] ionic liquid absorbed 0.056 mol of ethylene. At 130 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 97%, and the ethylene absorption capacity of the ionic liquid after the fourth-order desorption was restored by 100%.
[0040] Example 3
[0041] 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of gadolinium(III) chloride hexahydrate (GdCl3·6H2O) were dissolved in anhydrous methanol for 12 h. After the reaction ended, the solvent was removed at 60 °C using a rotary evaporator, and then the resulting product was dried under vacuum at 80 °C for 12 h to obtain a viscous liquid [P 666,14 3[GdCl6].
[0042] The above viscous liquid was characterized, and its decomposition temperature was measured to be 474.26 K, with a water content of <20 ppm. At 30 °C, each mole of [P 666,14 3[GdCl6] ionic liquid absorbed 0.033 mol of ethylene. At 140 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 98%, and the ethylene absorption capacity of the ionic liquid after the third-order desorption was restored by 100%.
[0043] Example 4
[0044] 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of dysprosium(III) chloride hexahydrate (DyCl3·6H2O) were dissolved in acetonitrile and stirred at 20 °C for 24 h. After the reaction ended, the solvent was removed at 60 °C using a rotary evaporator, and then the resulting product was dried under vacuum at 80 °C for 12 h to obtain a viscous liquid [P 666,14 3[DyCl6].
[0045] The above viscous liquid was characterized, and its decomposition temperature was measured to be 575.38 K, with a water content of <20 ppm. At 30 °C, each mole of [P 666,14 3[DyCl6] ionic liquid absorbed 0.062 mol of ethylene. At 150 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 99%, and the ethylene absorption capacity of the ionic liquid after the fifth-order desorption was restored by 100%.
[0046] Example 5
[0047] 3 mol of trihexyltetradecylphosphonium chloride (P 666,141 mol of trihexyltetradecylphosphonium chloride (P 666,14 3[ErCl6].
[0048] The above viscous liquid was characterized, and its decomposition temperature was measured to be 484.05 K, with a water content of <20 ppm. At 30 °C, each mole of [P 666,14 3[ErCl6] ionic liquid absorbed 0.087 mol of ethylene. At 130 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 96%, and the ethylene absorption capacity of the ionic liquid after 5-stage desorption was restored by 100%.
[0049] Example 6
[0050] Take 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of lanthanum chloride hexahydrate (LaCl3·6H2O) were dissolved in absolute ethanol, stirred at 25 °C for 18 h. After the reaction was completed, the solvent was removed at 60 °C using a rotary evaporator, and then the obtained product was dried under vacuum at 80 °C for 12 h to obtain a viscous liquid [P 666,14 3[LaCl6].
[0051] The above viscous liquid was characterized, and its decomposition temperature was measured to be 493.28 K, with a water content of <20 ppm. At 30 °C, each mole of [P 666,14 3[LaCl6] ionic liquid absorbed 0.04 mol of ethylene. At 160 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 99%, and the ethylene absorption capacity of the ionic liquid after 5-stage desorption was restored by 100%.
[0052] Example 7
[0053] Take 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of cerium chloride hexahydrate (CeCl3·6H2O) were dissolved in absolute ethanol, stirred at 25 °C for 18 h. After the reaction was completed, the solvent was removed at 60 °C using a rotary evaporator, and then the obtained product was dried under vacuum at 80 °C for 12 h to obtain a viscous liquid [P 666,14 3[CeCl6].
[0054] The above viscous liquid was characterized, and its decomposition temperature was measured to be 532.15 K, with a water content of <20 ppm. At 30 °C, each mole of [P 666,143[CeCl6] ionic liquid absorbs 0.043 mol of ethylene. Under the condition of 170 °C, the desorption rate of the first-stage ethylene absorbed on the ionic liquid reaches 99%, and the ethylene absorption capacity of the ionic liquid after 4-stage desorption is restored by 100%.
[0055] Example 8
[0056] Take 3 mol of trihexyltetradecylphosphonium chloride (P 666,14 Cl) and 1 mol of holmium(III) chloride hexahydrate (HoCl3·6H2O) and dissolve them in absolute ethanol. Stir at 25 °C for 18 h. After the reaction is completed, use a rotary evaporator to remove the solvent at 60 °C, and then dry the obtained product under vacuum at 80 °C for 12 h to obtain a viscous liquid [P 666,14 3[HoCl6].
[0057] Characterize the above viscous liquid, and measure its decomposition temperature to be 495.03 K, water content < 20 ppm. Under the condition of 30 °C, each mole of [P 666,14 3[HoCl6] ionic liquid absorbs 0.075 mol of ethylene. Under the condition of 140 °C, the desorption rate of the first-stage ethylene absorbed on the ionic liquid reaches 99%, and the ethylene absorption capacity of the ionic liquid after 4-stage desorption is restored by 100%.
[0058] Example 9
[0059] This example provides an ethylene complexing absorbent, and the difference in its preparation method from Example 1 is only that the usage amount of P 666,14 Cl is 3.5 mol, and the usage amount of YCl3·6H2O is 0.5 mol, and other conditions remain unchanged, to obtain a viscous liquid [P 666,14 7[YCl 10 .
[0060] Characterize the above viscous liquid, and measure its decomposition temperature to be 530.1 K, water content > 20 ppm. Under the condition of 30 °C, each mole of [P 666,14 7[YCl 10 ionic liquid absorbs 0.018 mol of ethylene. Under the condition of 140 °C, the desorption rate of the first-stage ethylene absorbed on the ionic liquid reaches 97%, and the ethylene absorption capacity of the ionic liquid after 5-stage desorption is restored by 100%.
[0061] Example 10
[0062] This example provides an ethylene complexing absorbent, and the difference in its preparation method from Example 1 is only that the usage amount of P 666,14 Cl is 2 mol, and the usage amount of YCl3·6H2O is 2 mol, and other conditions remain unchanged, to obtain a viscous liquid [P 666,14[YCl4].
[0063] The above viscous liquid was characterized, and its decomposition temperature was measured to be 458.16 K, with a water content > 20 ppm. At 30 °C, each mole of [P 666,14 [YCl4] ionic liquid absorbed 0.021 mol of ethylene. At 170 °C, the first-order ethylene desorption rate of the ethylene absorbed on the ionic liquid reached 94%, and the ethylene absorption capacity of the ionic liquid after 5-stage desorption was restored by 100%.
[0064] The applicant declares that the present invention illustrates an ethylene absorbent, its preparation method and application through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.
[0065] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.
[0066] In addition, it should be noted that in the various specific technical features described in the above specific embodiments, without conflict, they can be combined in any appropriate manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.
Claims
1. An ethylene complex absorbent, characterized in that, The ethylene complexing absorbent includes a rare earth metal ionic liquid having a structure represented by the following formula: wherein RE is a rare earth element, and y = x + 3; the rare earth element is selected from Y, Nd, Dy, Er, Ce, La, Ho; the ethylene complexing absorbent is prepared by the following method: Mixing and reacting trihexyltetradecylphosphonium chloride with rare earth chloride hexahydrate in an organic solvent, and removing the organic solvent to obtain the product; the molar ratio of trihexyltetradecylphosphonium chloride to rare earth chloride hexahydrate is (3 - 5):
1.
2. The preparation method of the ethylene complex absorbent according to claim 1, characterized in that, The preparation method includes: Mixing and reacting trihexyltetradecylphosphonium chloride with rare earth chloride hexahydrate in an organic solvent, and removing the organic solvent to obtain the product.
3. The preparation method of the ethylene complex absorbent according to claim 2, characterized in that, The molar ratio of trihexyltetradecylphosphonium chloride to rare earth chloride hexahydrate is (3 - 5):
1.
4. The preparation method of the ethylene complex absorbent according to claim 2, characterized in that, The organic solvent includes any one or a combination of at least two of ethanol, methanol, acetonitrile, ether, n-hexane, chloroform, dimethylformamide, acetone, pyridine or cyclohexane.
5. The preparation method of the ethylene complex absorbent according to claim 2, characterized in that, The temperature of the reaction is 15 - 40 °C, and the reaction time is 5 - 48 h.
6. The preparation method of the ethylene complex absorbent according to claim 2, characterized in that, The removal of the organic solvent includes first rotary evaporation treatment and then vacuum drying treatment.
7. The application of the ethylene complex absorbent according to claim 1 or the preparation method according to any one of claims 2 - 6 in the separation treatment of ethylene and ethane.
8. The application according to claim 7, characterized in that, The temperature of the absorption treatment is 25 - 50 °C, and the pressure of the absorption treatment is 0.1 - 1 MPa.
9. The application according to claim 7, characterized in that, The temperature of the desorption treatment is 120 - 180 °C, and the pressure of the desorption treatment is 0 - 0.1 MPa.