A water-soluble metal complex catalyst for preparing ethylene amine by dichloroethane ammoniation, a preparation method and application thereof

Abstract

The application discloses a water-soluble metal complex catalyst for preparing ethylene amine by ammoniating dichloroethane, a preparation method and application of the catalyst, and the catalyst has high activity and is a water-soluble homogeneous catalyst, can make the conversion rate of dichloroethane reach 99% at most, and can significantly improve the yield of ethylenediamine and diethylenetriamine; the preparation method is simple, environment-friendly, and has a very good application prospect. The catalyst is prepared by compounding a metal salt active body and an active functional ligand, wherein the metal salt active body is one of zirconium oxychloride, magnesium chloride, cerium chloride, zirconium chloride, titanium trichloride, dysprosium trifluoride, titanium tetrachloride or zinc bromide, and the active functional ligand is one of 1-ethyl-2-methyl imidazole chloride, tetraethyl ammonium bromide, N-methyl imidazole or 1,8-diazabicycloundec-7-ene bromide, and the mass ratio of the metal salt active body to the active functional ligand is 1:1-10.

Description

Technical Field

[0001] This invention relates to a catalyst, its preparation method, and its application; more specifically, it relates to a water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethylene amine, its preparation method, and its application. Background Technology

[0002] Ethyleneamine is an important fine chemical raw material and intermediate. It is a general term for a class of organic amine fine chemical products, mainly including acyclic polymers and cyclic amines. Acyclic polymers include ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and pentaethylenehexamine (PEHA), while cyclic amines include piperazine (PIP) and N-hydroxyethylpiperazine (HEP). Ethyleneamine products are used in industries such as pesticides, food, pharmaceuticals, automobiles, shipbuilding, civil engineering, water treatment, papermaking, rubber, textiles, and electronics. For example, it can be used as a basic raw material in epoxy resin curing agents, dye intermediates, electroplating solutions, surfactants, lubricant additives, rubber auxiliaries, metal chelating agents, and drug synthesis, with very wide applications.

[0003] Foreign countries developed ethyleneethyleneamine (EMI) production technology earlier, but there is still a significant gap between domestic and international EMI production processes and production scales. China still relies on imports to meet a portion of its EMI demand. Currently, there are two main large-scale industrial processes for EMI production: the dichloroethane (EDC) method and the ethanolamine (MEA) method, with the EDC method accounting for approximately 60% of production. The EDC method uses inexpensive and readily available raw materials, produces a wider range of products, and can yield high-value-added products such as polyethylenepolyamines (beyond triethylenetetramine) that cannot be produced by the MEA method. It also features a more complete reaction, higher conversion rate, and the ability to adjust process parameters to obtain different product structures and more flexible control over product composition. The EDC method uses ammonia and dichloroethane as raw materials to produce EMI, as shown in the following reaction equation:

[0004] general formula:

[0005] Early industrial dichloroethane processes for preparing ethylenediamine typically did not use a catalyst. They required a high concentration of excess ammonia (50-60% by mass) and dichloroethane, with a molar ratio of ammonia to dichloroethane of 15-30:1. The reaction was carried out at a high temperature of 120-180°C and a high pressure of 4-7 MPa for 1 hour to produce ethylenediamine hydrochloride, which was then treated with an alkali to obtain the ethylenediamine series products. This process suffered from high energy consumption, high operating costs, difficulty in separating and reusing excess high-concentration ammonia and wastewater, and difficulty in mixing the dichloroethane and ammonia phases. Early processes also used Ni-Re series catalysts, but the aforementioned problems persisted. Therefore, in recent years, domestic scholars have continued to research improvements to this process.

[0006] To address the above issues, Chinese patent CN101862683A proposes using a catalyst composed of 2,2-bipyridine or 1,3-diazolium and cuprous chloride or ferrous chloride. Using this catalyst, the required ammonia concentration is reduced to 30%, the temperature is 135°C, the ammonia-alkane molar ratio is 6:1, and the reaction time is 15 min, resulting in an ethylene amine product yield of 82-95%. However, cuprous chloride is insoluble in the aqueous phase using the aforementioned catalyst, which affects the reaction efficiency. Chinese patent CN103752345B proposes a catalyst composed of 2,4,6-tris(dimethylaminomethyl)phenol and stannous chloride. Using this catalyst, the required ammonia concentration is reduced to 20%, the temperature is 125°C, the ammonia-alkane molar ratio is 5:1, and the reaction time is 15 min, resulting in an ethylene amine product yield of 82-95%. Chinese patent CN106669824A proposes a catalyst composed of stannous chloride, 2,4-dichlorophenoxyacetic acid, and benzophenone. Stannous chloride has a certain degree of toxicity and poses safety concerns. There are still practical problems that are difficult to solve when the catalyst is put into production. Chinese patent CN102151571A proposes the use of a catalyst whose main active components are cobalt and lanthanides. The reaction conditions are 35% ammonia concentration, 110℃ temperature, ammonia-to-alkane molar ratio of 3:1, and a reaction time of 25 min. The yield of ethylene amine product is 99%. However, this catalyst is a solid catalyst, which has problems such as complex preparation process, harsh preparation conditions, and expensive catalyst raw materials. In summary, the existing technology for preparing ethylene amine products by dichloroethane still has the following problems: (1) the raw material has a high concentration of excess ammonia, which poses a great safety risk; (2) the reaction conditions are high temperature and high pressure, the reaction time is long, the energy consumption is high, and the operating cost is high; (3) dichloroethane and ammonia are difficult to mix.

[0007] Furthermore, the addition of catalysts obtained by combining halometallic salts and organic cations can effectively improve the ammoniation efficiency of dichloroethane, solving some problems in the process of preparing ethylene amine from dichloroethane, such as reducing the concentration and amount of ammonia used. However, existing catalysts also have shortcomings and problems, such as low or harmful catalytic activity, insufficient water solubility, complex preparation processes, and high prices. Therefore, further research and development of catalysts, preparation methods, and applications with high catalytic activity, mild conditions, and simple preparation processes are still needed. Summary of the Invention

[0008] The purpose of this invention is to address the problems existing in the industrial catalyst technology of the prior art by providing a water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethylene amine. This catalyst has high activity and is a water-soluble homogeneous catalyst, which can improve the mixing of the two phases, make the reaction conditions milder, reduce the required reaction temperature and pressure, and greatly reduce the required ammonia concentration and reaction time.

[0009] Another objective of this invention is to provide a method for preparing the water-soluble metal complex catalyst for the amination of dichloroethane to ethylenediamine and its application. This method is simple, uses mild reaction conditions, is environmentally friendly, and has excellent prospects for industrial application. The prepared water-soluble metal complex catalyst for the amination of dichloroethane to ethylenediamine can achieve a conversion rate of up to 99% for dichloroethane and can significantly improve the yields of ethylenediamine and diethylenetriamine.

[0010] This invention is achieved through the following technical solution:

[0011] The water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethylene amine of the present invention is prepared by compounding a metal salt active host with an active functional ligand. The metal salt active host is one of zirconium oxychloride, magnesium chloride, cerium trichloride, zirconium chloride, titanium trichloride, dysprosium trifluoride, titanium tetrachloride, or zinc bromide. The active functional ligand is one of 1-ethyl-2-methylimidazolium chloride, tetraethylammonium bromide, N-methylimidazolium, or 1,8-diazabicycloundec-7-ene bromide. The mass ratio of the metal salt active host to the active functional ligand is 1:1-10.

[0012] The method for preparing the water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethylene amine according to the present invention includes the following steps: first, preparing an aqueous solution of the metal salt active host; after it is fully dissolved, adding an organic active functional ligand to the aqueous solution of the metal salt active host in proportion; and heating and stirring at 50-70°C for more than 3 hours to obtain the water-soluble metal complex catalyst.

[0013] The preparation method of the water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethylene amine according to the present invention is further described in that the metal salt active host is one of zirconium oxychloride, magnesium chloride, cerium trichloride, zirconium chloride, titanium trichloride, dysprosium trifluoride, titanium tetrachloride, or zinc bromide, and the active functional ligand is one of 1-ethyl-2-methylimidazolium chloride, tetraethylammonium bromide, N-methylimidazolium, or 1,8-diazabicycloundec-7-ene bromide, wherein the mass ratio of the metal salt active host to the active functional ligand is 1:1-10.

[0014] The water-soluble metal complex catalyst described above for the preparation of ethylene amine by amination of dichloroethane can be applied in the preparation of ethylene amine by amination of dichloroethane.

[0015] The water-soluble metal complex catalyst for the preparation of ethylenediamine by ammoniation of dichloroethane described above can be further applied in the preparation of ethylenediamine by ammoniation of dichloroethane. A further technical solution includes the following steps: adding the water-soluble metal complex catalyst, ammonia, and dichloroethane to a reaction apparatus in a specific ratio; heating and controlling the temperature at 100–120°C for a reaction time of 4–20 min; after the reaction, ethylenediamine hydrochloride is obtained, which is then neutralized with alkali, and the ethylenediamine product is separated. A further technical solution is that the amount of the water-soluble metal complex catalyst is preferably 0.1–1% of the mass of dichloroethane, wherein the dichloroethane is 1,2-dichloroethane. A further technical solution is that the reaction pressure is 1–1.5 MPa, the ammonia concentration is 15–25%, and the ammonia-to-ethane molar ratio is 4–8:1.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] This invention provides a homogeneous catalyst with a simple preparation process, high activity, controllable product distribution, and mild conditions. The two-phase mixing is improved, the reaction conditions are milder, the required reaction temperature and pressure are reduced, and the required ammonia concentration and reaction time are greatly reduced. This can reduce industrial costs, improve industrial production efficiency, and enhance the market competitiveness of products in many ways.

[0018] Based on existing catalysts for the preparation of ethylene amine products using the dichloroethane method, this invention conducts an in-depth analysis of the atomic structure and metal element characteristics of the metal salts used. It proposes using Lewis acid metal salts, with the addition of organic cations as active functional ligands to coordinate and complex with them, resulting in a water-soluble metal complex catalyst with high catalytic performance. Given the corrosive nature of Lewis acid metal salts, the added organic components also act as corrosion inhibitors. Furthermore, the surfactant function is utilized to achieve uniform mixing of the two phases. Additionally, the selected metal salt and organic functional ligand possess both water solubility and water stability.

[0019] Creative experiments unexpectedly revealed that adding only the organic active functional ligand did not significantly change the reaction yield compared to the uncatalyzed reaction, indicating that the selected organic component had no significant effect on the reaction conversion. Adding only the metal salt active host also improved the reaction conversion, with the conversion of dichloroethane reaching up to 97%. However, adding the water-soluble metal complex catalyst formulated according to this invention significantly improved the yield of polyethylenepolyamines, with the conversion of dichloroethane reaching up to 99%, and significantly increased the yields of ethylenediamine and diethylenetriamine. The added metal salt active host and organic active functional ligand exhibited a synergistic effect; the metal ions and organic functional ligands could form complexes with ammonia, possessing good surface activity and hydrophilic and lipophilic groups. This effectively reduced the surface tension of the two-phase liquid reactants, greatly improving the mixing degree of the reactants, increasing the mass transfer rate, and reducing the required reaction conditions, while simultaneously significantly improving both the reaction rate and the reaction conversion.

[0020] Compared with the prior art, the present invention also has the following technical effects:

[0021] (1) The water-soluble metal complex catalyst of the present invention is inexpensive, highly active, stable and non-toxic;

[0022] (2) The water-soluble metal complex catalyst of the present invention effectively reduces the ammonia concentration, temperature, pressure and reaction time required for the reaction, thereby reducing production costs;

[0023] (3) The water-soluble metal complex catalyst of the present invention effectively improves the degree of mixing between the two phases of the raw materials, and improves the conversion rate of dichloroethane and the yield of ethylene amine products;

[0024] (4) By adjusting the formulation and reaction conditions of the water-soluble metal complex catalyst of the present invention, the product structure can be flexibly adjusted. The ethylene amine products that can be prepared include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, piperazine, N-hydroxyethylpiperazine, etc.

[0025] (5) The water-soluble metal complex catalyst of the invention is a homogeneous catalyst and can be used in batch reactors, tubular reactors and microchannel reactors, etc. Detailed Implementation

[0026] The present invention will be further described below with reference to the embodiments, but these embodiments do not limit the scope of protection of the present invention.

[0027] Example 1

[0028] Preparation of water-soluble metal complex catalyst ZrOCl2-EMIC:

[0029] 20 mL of deionized water solution and 0.01 mol of zirconium oxychloride were added to a round-bottom flask. After the zirconium oxychloride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the zirconium oxychloride solution. After heating and stirring at 70 °C for 3 h, the ZrOCl2-EMIC water-soluble metal complex catalyst was obtained.

[0030] Preparation of ethylene amine products:

[0031] Ethyleneamine was prepared using the dichloroethane method in a 16 mL microchannel reactor. ZrOCl2-EMIC catalyst was added at 0.3% of the feed dichloroethane mass. The temperature was controlled at 100℃, the pressure at 1 MPa, the ammonia concentration at 15%, the ammonia-to-ethane molar ratio at 4:1, and the reaction time at 5 min. The dichloroethane conversion rate of the ethyleneamine product was 99.2%, the yield of ethylenediamine was 52.7%, the yield of diethylenetriamine was 37.7%, and the yield of other polyethylenepolyamines was 8.8%.

[0032] Example 2

[0033] Other conditions and parameters are the same as in Implementation 1, except that the reaction apparatus is changed to a 250mL tubular reaction apparatus, the reaction time is 10min, the conversion rate of ethylene amine product dichloroethane is 99%, the yield of ethylenediamine is 42.3%, the yield of diethylenetriamine is 26.8%, and the yield of other polyethylenepolyamines is 29.9%.

[0034] Example 3

[0035] Preparation of ethylene amine products:

[0036] The reaction apparatus was changed to a 100mL batch reactor. The catalyst used was the ZrOCl2-EMIC water-soluble metal complex catalyst prepared in Example 1. The catalyst was added at 0.5% of the mass of the feed dichloroethane. The temperature was controlled at 120℃, the reaction pressure at 1.3MPa, the ammonia concentration at 25%, the ammonia-to-ethane molar ratio at 8:1, and the reaction time at 20min to prepare ethylenediamine. The dichloroethane conversion rate of the ethylenediamine product was 99%, the yield of ethylenediamine was 45%, the yield of diethylenetriamine was 27%, and the yield of other polyethylenepolyamines was 27%.

[0037] Example 4

[0038] Preparation of ZrOCl2-EMIC-1 water-soluble metal complex catalyst:

[0039] 20 mL of deionized water solution and 0.01 mol of zirconium oxychloride were added to a round-bottom flask. After the zirconium oxychloride was fully dissolved, 0.005 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the zirconium oxychloride solution. After heating and stirring at 70 °C for 3 h, the water-soluble metal complex catalyst ZrOCl2-EMIC-1 was obtained.

[0040] Preparation of ethylene amine products:

[0041] The rest is the same as in Example 3, except that the catalyst was changed to a ZrOCl2-EMIC-1 water-soluble metal complex catalyst. The conversion rate of ethylenediamine to dichloroethane was 97.3%, the yield of ethylenediamine was 37.4%, the yield of diethylenetriamine was 7%, and the yield of other polyethylenepolyamines was 52.8%.

[0042] Example 5

[0043] Preparation of water-soluble metal complex catalyst TiCl3-EMIC:

[0044] 20 mL of deionized water solution and 0.01 mol of titanium trichloride were added to a round-bottom flask. After the titanium trichloride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the titanium trichloride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the TiCl3-EMIC water-soluble metal complex catalyst.

[0045] Preparation of ethylene amine products:

[0046] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst TiCl3-EMIC. The conversion rate of dichloroethane from the ethylene amine product is 96%, the yield of ethylenediamine is 47%, the yield of diethylenetriamine is 8%, and the yield of the remaining polyethylenepolyamines is 41%.

[0047] Example 6

[0048] Preparation of water-soluble metal complex catalyst MgCl2-EMIC:

[0049] 20 mL of deionized water solution and 0.01 mol of magnesium chloride were added to a round-bottom flask. After the magnesium chloride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the magnesium chloride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the MgCl2-EMIC water-soluble metal complex catalyst.

[0050] Preparation of ethylene amine products:

[0051] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst MgCl2-EMIC. The conversion rate of dichloroethane from the ethylene amine product is 95%, the yield of ethylenediamine is 55%, the yield of diethylenetriamine is 4%, and the yield of the remaining polyethylenepolyamines is 36%.

[0052] Example 7

[0053] Preparation of water-soluble metal complex catalyst CeCl3-EMIC:

[0054] 20 mL of deionized water solution and 0.01 mol of cerium trichloride were added to a round-bottom flask. After the cerium trichloride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the cerium trichloride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the CeCl3-EMIC water-soluble metal complex catalyst.

[0055] Preparation of ethylene amine products:

[0056] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst CeCl3-EMIC. The conversion rate of dichloroethane from the ethylene amine product is 95%, the yield of ethylenediamine is 40%, the yield of diethylenetriamine is 13%, and the yield of the remaining polyethylenepolyamines is 42%.

[0057] Example 8

[0058] Preparation of water-soluble metal complex catalyst ZrCl4-EMIC:

[0059] 20 mL of deionized water solution and 0.01 mol of zirconium chloride were added to a round-bottom flask. After the zirconium chloride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the zirconium chloride solution. After heating and stirring at 70 °C for 3 h, the ZrCl4-EMIC water-soluble metal complex catalyst was obtained.

[0060] Preparation of ethylene amine products:

[0061] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst ZrCl4-EMIC. The conversion rate of ethylenediamine product dichloroethane is 95%, the yield of ethylenediamine is 23%, the yield of diethylenetriamine is 6%, and the yield of other polyethylenepolyamines is 66%.

[0062] Example 9

[0063] Preparation of water-soluble metal complex catalyst SbF3-EMIC:

[0064] 20 mL of deionized water solution and 0.01 mol of dysprosium trifluoride were added to a round-bottom flask. After the dysprosium trifluoride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the dysprosium trifluoride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the SbF3-EMIC water-soluble metal complex catalyst.

[0065] Preparation of ethylene amine products:

[0066] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst SbF3-EMIC. The conversion rate of ethylene amine product dichloroethane is 90%, the yield of ethylenediamine is 38%, the yield of diethylenetriamine is 2%, and the yield of the remaining polyethylenepolyamines is 50%.

[0067] Example 10

[0068] Preparation of water-soluble metal complex catalyst TiCl4-EMIC:

[0069] 20 mL of deionized water solution and 0.01 mol of titanium tetrachloride were added to a round-bottom flask. After the titanium tetrachloride was fully dissolved, 0.02 mol of 1-ethyl-2-methylimidazolium chloride (EMIC) was added to the titanium tetrachloride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the TiCl4-EMIC water-soluble metal complex catalyst.

[0070] Preparation of ethylene amine products:

[0071] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst TiCl4-EMIC. The conversion rate of dichloroethane from ethylene amine is 85%, the yield of ethylenediamine is 33%, the yield of diethylenetriamine is 1%, and the yield of the remaining polyethylenepolyamines is 51%.

[0072] Example 11

[0073] Preparation of water-soluble metal complex catalyst ZrOCl2-TEAB:

[0074] 20 mL of deionized water solution and 0.01 mol of zirconium oxychloride were added to a round-bottom flask. After the zirconium oxychloride was fully dissolved, 0.02 mol of tetraethylammonium bromide (TEAB) was added to the zirconium oxychloride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the ZrOCl2-TEAB water-soluble metal complex catalyst.

[0075] Preparation of ethylene amine products:

[0076] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst ZrOCl2-TEAB. The conversion rate of ethylene amine product dichloroethane is 96%, the yield of ethylenediamine is 34%, the yield of diethylenetriamine is 5%, and the yield of other polyethylenepolyamines is 57%.

[0077] Example 12

[0078] Preparation of water-soluble metal complex catalyst ZrOCl2-NMI:

[0079] 20 mL of deionized water solution and 0.01 mol of zirconium oxychloride were added to a round-bottom flask. After the zirconium oxychloride was fully dissolved, 0.02 mol of N-methylimidazole (NMI) was added to the zirconium oxychloride solution. The mixture was heated and stirred at 70 °C for 3 h to obtain a ZrOCl2-NMI water-soluble metal complex catalyst.

[0080] Preparation of ethylene amine products:

[0081] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst ZrOCl2-NMI. The conversion rate of ethylene amine product dichloroethane is 94%, the yield of ethylenediamine is 28%, the yield of diethylenetriamine is 25%, and the yield of other polyethylenepolyamines is 41%.

[0082] Example 13

[0083] Preparation of water-soluble metal complex catalyst ZnBr2-[HDBU]Br:

[0084] 20 mL of deionized water solution and 0.01 mol of zinc bromide were added to a round-bottom flask. After the zinc bromide was fully dissolved, 0.02 mol of 1,8-diazabicycloundec-7-ene bromide ([HDBU]Br) was added to the zinc bromide solution. The mixture was heated and stirred at 70 °C for 3 h to obtain the ZnBr2-[HDBU]Br water-soluble metal complex catalyst.

[0085] Preparation of ethylene amine products:

[0086] The rest is the same as in Example 3, except that the catalyst is changed to a water-soluble metal complex catalyst ZnBr2-[HDBU]Br. The conversion rate of dichloroethane of the ethylene amine product is 92%, the yield of ethylenediamine is 31%, the yield of diethylenetriamine is 13%, and the yield of the remaining polyethylenepolyamines is 48%.

[0087] The results of the ethylene amine products in Examples 1-13 are shown in Table 1.

[0088] Table 1 Results of Ethyleneamine Products in Examples 1-13

[0089]

[0090] The results above show that the selected water-soluble metal complex catalyst, which combines Lewis acid metal salts with organic cations, exhibits good catalytic performance in this reaction system.

[0091] The water-soluble metal complex catalyst provided by this invention has advantages such as high catalytic activity, controllable distribution, good stability, and simple preparation. In the process of preparing ethylenediamine from dichloroethane, using the catalyst under the following conditions: catalyst feed weight is 0.1-1% of the mass of the feed dichloroethane, temperature is 100-120℃, pressure is 1-1.5 MPa, ammonia concentration is 15-25%, ammonia-to-ethane molar ratio is 4-8:1, and reaction time is 4-20 min, which allows the conversion rate of the feed dichloroethane to reach up to 99%. At this point, the yield of ethylenediamine is 45%, the yield of diethylenetriamine is 27%, and the yield of other polyethylenepolyamines is 27%. The highest yield of ethylenediamine can reach 55%, at which point the conversion rate of dichloroethane is 95%, the yield of diethylenetriamine is 4%, and the yield of other polyethylenepolyamines is 36%.

[0092] The catalyst of this invention incorporates an active host metal salt and an organic active functional ligand that synergistically enhance the reaction system, reducing the required reaction conditions while exhibiting excellent surface activity. Possessing both hydrophilic and lipophilic groups, it effectively reduces the surface tension between the two liquid phases of the raw materials, significantly improving the mixing degree of the reactants and resulting in a substantial increase in both reaction rate and conversion rate. From an industrial perspective, the addition of this catalyst significantly reduces the ammonia concentration, ammonia volume, temperature, and pressure required for the preparation of ethylene amine using the dichloroethane method, thereby reducing equipment investment and production costs. Furthermore, it accelerates the mixing and reaction rate of raw materials, reduces production time, and increases process yield. Different formulations can control different product compositions, resulting in more flexible product structures. This approach can reduce industrial costs from multiple perspectives, improve industrial production efficiency, and enhance product market competitiveness, demonstrating significant promise for industrial applications.

Claims

1. A water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethyleneamine, characterized in that, The catalyst is prepared by combining a metal salt active host with an active functional ligand. The metal salt active host is one of zirconium oxychloride, magnesium chloride, cerium trichloride, zirconium chloride, titanium trichloride, dysprosium trifluoride, titanium tetrachloride, or zinc bromide. The active functional ligand is one of 1-ethyl-2-methylimidazolium chloride, tetraethylammonium bromide, N-methylimidazolium, or 1,8-diazabicycloundec-7-ene bromide. The mass ratio of the metal salt active host to the active functional ligand is 1:1-10.

2. A method for preparing a water-soluble metal complex catalyst for the amination of dichloroethane to prepare ethyleneamine as described in claim 1, characterized in that, The process includes the following steps: First, prepare an aqueous solution of the active metal salt substrate. After it is fully dissolved, add an organic active functional ligand to the aqueous solution of the active metal salt substrate in proportion. Heat and stir at 50~70℃ for more than 3 hours to obtain a water-soluble metal complex catalyst.

3. The application of the water-soluble metal complex catalyst as described in claim 1 for the preparation of ethylenediamine by ammoniation of dichloroethane in the preparation of ethylenediamine.

4. The application according to claim 3, characterized in that, The process includes the following steps: adding water-soluble metal complex catalyst, ammonia and dichloroethane to the reaction apparatus in proportion, heating and controlling the temperature at 100~120℃ for 4~20 min, obtaining ethylene amine hydrochloride after the reaction, then adding alkali for neutralization, and separating to obtain the ethylene amine product.

5. The application according to claim 4, characterized in that, The amount of the water-soluble metal complex catalyst is 0.1-1% of the mass of dichloroethane, and the dichloroethane is 1,2-dichloroethane.

6. The application according to claim 4, characterized in that, The reaction pressure is 1~1.5MPa, the ammonia concentration is 15~25%, and the ammonia-alkane molar ratio is 4~8:1.

Images