A kind of N 1 Preparation method of 1,2-(2-aminoethyl)-1,2-ethylenediamine

Abstract

This invention provides an N 1 A method for preparing (2-aminoethyl)-1,2-ethylenediamine includes the following steps: reacting iminodiacetonitrile with hydrogen gas in a reaction liquid system containing a solvent, a hydrogenation catalyst, and a catalyst protectant to generate N2O2. 1 -(2-aminoethyl)-1,2-ethylenediamine; wherein the catalyst protectant comprises one or more of nickel carbonyl, iron carbonyl, nickel tetraamine, and cobalt tetraamine. This invention can suppress the decrease in catalytic activity of hydrogenation catalysts, avoid catalyst deactivation, and improve N... 1 Selectivity and yield of (2-aminoethyl)-1,2-ethylenediamine.

Description

Technical Field

[0001] This invention relates to an N 1 The preparation method of -(2-aminoethyl)-1,2-ethylenediamine belongs to the field of amine compound synthesis. Background Technology

[0002] N 1 (2-Aminoethyl)-1,2-ethylenediamine (DETA), also known as diethylenetriamine, is a yellow, hygroscopic, transparent, viscous liquid with a pungent ammonia odor. It readily absorbs moisture and carbon dioxide from the air. Diethylenetriamine has a wide range of applications, including the synthesis of polyamide resins, paper strengthening agents, metal chelating agents, surfactants, lubricants, and epoxy resin curing agents.

[0003] Currently, DETA is mainly produced via the dichloroethane (EDC) ammoniation method or the ethanolamine (MEA) method. The EDC ammoniation method is characterized by its ability to proceed without a catalyst, being a rapid and exothermic reaction. Because the main product, ethylenediamine (EDA), has stronger basicity and nucleophilicity than the feedstock NH3, it readily participates as an intermediate in the reaction, initiating a chain reaction to generate DETA or other polyethylenepolyamines. Therefore, the products obtained by the EDC ammoniation method are widely distributed, primarily consisting of linear polyethylenepolyamines. However, the EDC ammoniation method suffers from problems such as high energy consumption, severe equipment corrosion, significant waste generation, and high costs, limiting its application.

[0004] The MEA process, also known as MEA reductive amination or direct amination, refers to the amination reaction between MEA and NH3 in the presence of a catalyst and an H2 atmosphere, producing amine products and water. The main amine product is EDA, with high-value-added byproducts including DETA, PIP, and piperazine derivatives. MEA reductive amination is a gas-liquid-solid three-phase reaction, using a transition metal dehydrogenation-hydrogenation catalyst. The reaction temperature and pressure are typically in the range of 150-200℃ and 3-30 MPa, respectively. The reactor used can be a high-pressure autoclave or a fixed-bed reactor. The MEA process generally suffers from problems such as catalyst deactivation due to coking and high raw material costs for ethylenediamine, limiting its application.

[0005] In comparison, the preparation of corresponding organic amines from nitrile hydrogenation has advantages such as simpler processes and more environmentally friendly methods, and is gradually gaining widespread application. Among these, the hydrogenation reaction of iminodiacetonitrile (IDAN) in the presence of a hydrogenation catalyst is a feasible direction for the preparation of DETA. However, in the process of preparing DETA through the hydrogenation reaction of IDAN, the hydrogenation catalysts used are mainly metal catalysts. Since raw materials such as IDAN are prone to decomposition under high-temperature conditions, producing CN... -Factors such as these can easily lead to a decrease in the activity of hydrogenation catalysts or even catalyst deactivation. This is especially true since industrial-grade IDAN is commonly used to prepare DETA. Industrial-grade IDAN, due to its high impurity content, cannot be used directly and requires a series of pretreatments, including deacidification, before being used to prepare DETA. However, industrial-grade IDAN is prone to polymerization and decomposition after these pretreatments, and especially when it enters the hydrogenation reactor, it easily decomposes at high temperatures to produce CN. - It easily forms complexes with hydrogenation catalysts, causing the hydrogenation catalyst to continuously leak out, or even block the catalyst channels, resulting in a decrease in catalyst activity or even deactivation.

[0006] For example, US2002058842 discloses a method for hydrogenating IDAN using Raney cobalt as a catalyst in an N,N-dimethylformamide (DMF) system at a reaction temperature of 100°C and a reaction pressure of 190 bar, which suffers from problems such as easy catalyst deactivation; WO2008104583A1 discloses a method for preparing DETA by hydrogenation of a mixture of IDAN and aminoacetonitrile, which suffers from the problem that raw materials such as IDAN and aminoacetonitrile are prone to decomposition to produce CN. - This leads to defects such as reduced or even deactivated catalyst activity, and the easy polymerization and decomposition of aminoacetonitrile at room temperature, resulting in complex and variable product composition in the reaction solution, which affects the subsequent separation of DETA.

[0007] Furthermore, in the process of preparing DETA via the hydrogenation reaction of IDAN, the conversion rate of IDAN and the selectivity of DETA need to be further improved.

[0008] In summary, in the process of preparing DETA via the hydrogenation reaction of IDAN, how to suppress the decrease in the activity of the hydrogenation catalyst, avoid the deactivation of the hydrogenation catalyst, and simultaneously improve the conversion rate of IDAN and the selectivity of DETA are technical problems that urgently need to be solved in this field. Summary of the Invention

[0009] This invention provides an N 1 The preparation method of -(2-aminoethyl)-1,2-ethylenediamine can inhibit the decrease in the activity of hydrogenation catalyst, avoid the deactivation of hydrogenation catalyst, and improve the conversion rate of IDAN and the selectivity of DETA, effectively overcoming the defects of the existing technology.

[0010] This invention provides an N 1 A method for preparing -(2-aminoethyl)-1,2-ethylenediamine includes the following steps: reacting iminodiacetonitrile with hydrogen in a reaction liquid system containing a solvent, a hydrogenation catalyst, and a catalyst protectant to generate N. 1-(2-aminoethyl)-1,2-ethylenediamine; wherein the catalyst protectant includes one or more of nickel carbonyl, iron carbonyl, nickel tetraamine, and cobalt tetraamine.

[0011] According to one embodiment of the present invention, the hydrogenation catalyst includes one or more of Raney nickel, Raney cobalt, and supported catalysts; preferably, the supported catalyst includes a support and an active component supported on the support, wherein the support includes one or more of alumina, silicon oxide, zinc oxide, titanium oxide, magnesium oxide, activated carbon, diatomaceous earth, and silica gel, and the active component includes one or more of sodium, potassium, titanium, manganese, iron, cobalt, copper, molybdenum, nickel, ruthenium, rhodium, palladium, and platinum.

[0012] According to one embodiment of the present invention, the mass ratio of the hydrogenation catalyst to the iminodiacetonitrile is 5% to 40%.

[0013] According to one embodiment of the present invention, the mass ratio of the catalyst protectant to the hydrogenation catalyst is 1% to 10%.

[0014] According to one embodiment of the present invention, the reaction liquid system further includes an auxiliary agent, which includes a metal oxide and / or a metal hydroxide; preferably, the metal element in the metal oxide includes an alkali metal and / or an alkaline earth metal, and the metal element in the metal hydroxide includes an alkali metal and / or an alkaline earth metal.

[0015] According to one embodiment of the present invention, the mass ratio of the auxiliary agent to the hydrogenation catalyst is 10% to 20%.

[0016] According to one embodiment of the present invention, the alkali metal includes lithium and / or potassium; and / or, the alkaline earth metal includes calcium.

[0017] According to one embodiment of the present invention, the solvent includes one or more of dioxane, tetrahydrofuran, methanol, ethanol, propanol, isopropanol, n-butanol, ethyl acetate, and butyl acetate.

[0018] According to one embodiment of the present invention, the reaction conditions are: reaction temperature of 80°C to 180°C, hydrogen pressure of 3MPa to 8MPa, and reaction time of 60min to 300min.

[0019] According to one embodiment of the present invention, the iminodiacetonitrile is obtained from an iminodiacetonitrile raw material after pretreatment. The pretreatment process includes: extracting the iminodiacetonitrile raw material with an extractant to obtain the iminodiacetonitrile; wherein the extractant includes water and a first organic solvent; preferably, the pretreatment process includes: extracting the iminodiacetonitrile raw material with an extractant to obtain a raw material liquid containing the iminodiacetonitrile; the process of reacting the iminodiacetonitrile with hydrogen in a reaction liquid system containing a solvent, a hydrogenation catalyst, and a catalyst protectant includes: adding the raw material liquid containing the iminodiacetonitrile to the reaction liquid system, and reacting the iminodiacetonitrile with hydrogen to generate N. 1 -(2-aminoethyl)-1,2-ethylenediamine, to generate the N 1 -(2-aminoethyl)-1,2-ethylenediamine; wherein, during the process of adding the feed solution containing the iminodiacetonitrile to the reaction solution system, the space velocity of the feed solution containing the iminodiacetonitrile is 1-5 g / min.

[0020] The implementation of this invention has at least the following beneficial effects: it allows IDAN to react with hydrogen in the presence of a solvent, a hydrogenation catalyst, and a catalyst protectant to generate N. 1 -(2-Aminoethyl)-1,2-ethylenediamine, by introducing a specific catalyst protectant (including one or more of nickel carbonyl, iron carbonyl, nickel tetraamine, and cobalt tetraamine) into the process of preparing DETA based on IDAN hydrogenation, can maintain the activity of the hydrogenation catalyst, inhibit the decrease in hydrogenation catalyst activity, avoid deactivation of the hydrogenation catalyst, ensure the stable and continuous production of DETA, and simultaneously improve the conversion rate of IDAN and the selectivity of DETA, thereby increasing the yield of DETA. This is of great significance for practical industrial applications. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides an N 1 A method for preparing -(2-aminoethyl)-1,2-ethylenediamine (DETA) includes the following steps: reacting iminodiacetonitrile (IDAN) with hydrogen in a reaction liquid system containing a solvent, a hydrogenation catalyst, and a catalyst protectant (hereinafter referred to as the hydrogenation reaction) to produce N... 1-(2-aminoethyl)-1,2-ethylenediamine (DETA); wherein the catalyst protectant includes one or more of nickel carbonyl, iron carbonyl, nickel tetraamine, and cobalt tetraamine.

[0023] In the above-mentioned DETA preparation process, by reacting IDAN with hydrogen in a reaction liquid system containing solvent, hydrogenation catalyst and catalyst protectant, it is possible to improve both the conversion rate of IDAN and the selectivity of DETA, thereby increasing the yield of DETA.

[0024] According to the inventors' research, in the preparation process of the aforementioned DETA, during the hydrogenation reaction, the catalyst protectant can react with free CN produced in the reaction system due to factors such as the decomposition of IDAN. - Combined, thus avoiding CN - The complexation with the hydrogenation catalyst, and the resulting adverse effects on the adsorption performance and pore structure of the hydrogenation catalyst, ensure that the main body of the hydrogenation catalyst is not destroyed and lost, thereby maintaining the activity of the hydrogenation catalyst, avoiding deactivation of the hydrogenation catalyst, improving the service life of the catalyst, and ensuring the stable and continuous production of DETA. Specifically, this can be manifested in the fact that after repeated hydrogenation reactions (such as 5 batches) using the hydrogenation catalyst, a high conversion rate of IDAN and DETA selectivity can still be maintained, thus improving the yield of DETA.

[0025] Specifically, the aforementioned hydrogenation catalyst may include a metal catalyst and / or a supported catalyst. The metal catalyst may include Raney nickel and / or Raney cobalt. The supported catalyst includes a support and an active component supported on the support. The support may include one or more of alumina, silica, zinc oxide, titanium oxide, magnesium oxide, activated carbon, diatomaceous earth, and silica gel. The active component may include one or more of sodium, potassium, titanium, manganese, iron, cobalt, copper, molybdenum, nickel, ruthenium, rhodium, palladium, and platinum.

[0026] In some embodiments, the hydrogenation catalyst includes one or more of Raney nickel, Raney cobalt, and the above-mentioned supported catalysts. In the preparation of DETA, using this hydrogenation catalyst, and simultaneously introducing the above-mentioned catalyst protectant into the reaction liquid system, helps to further suppress the decrease in catalytic activity of the hydrogenation catalyst, avoid catalyst deactivation, and further improve both the conversion rate of IDAN and the selectivity of DETA, thereby increasing the yield of DETA.

[0027] In some embodiments, the mass ratio of hydrogenation catalyst to IDAN in the above reaction system can be 5% to 40%, for example, 5%, 8%, 10%, 13%, 15%, 18%, 20%, 25%, 28%, 30%, 33%, 35%, 38%, 40%, or any combination thereof, which is beneficial to improve the conversion rate of IDAN and the selectivity of DETA, and improve the yield of DETA.

[0028] In some embodiments, the mass ratio of the catalyst protectant to the hydrogenation catalyst in the above reaction liquid system can be 1% to 10%, for example, a range of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or any two of these, which is beneficial to further suppress the decrease in catalytic activity of the hydrogenation catalyst and improve the service life of the hydrogenation catalyst.

[0029] In some embodiments, the above-described reaction system further includes an auxiliary agent, which may include metal oxides and / or metal hydroxides. The metal element in the metal oxide includes alkali metals and / or alkaline earth metals, and the metal element in the metal hydroxide includes alkali metals and / or alkaline earth metals. By introducing an auxiliary agent into the above-described reaction system, it is beneficial to further improve the conversion rate of IDAN and the selectivity of DETA, thereby increasing the yield of DETA.

[0030] Specifically, the aforementioned alkali metals may include lithium (Li) and / or potassium (K), and / or alkaline earth metals may include calcium (Ca). That is, the metal elements in the metal oxides may include one or more of Li, K, and Ca, and the metal elements in the metal hydroxides may include one or more of Li, K, and Ca.

[0031] In some specific embodiments, the metal oxide may include one or more of lithium oxide, potassium oxide, and calcium oxide.

[0032] In some specific embodiments, the metal hydroxide described above may include one or more of lithium hydroxide (LiOH), potassium hydroxide, and calcium hydroxide.

[0033] Specifically, in the above reaction system, the mass ratio of the auxiliary agent to the hydrogenation catalyst (i.e., the amount of auxiliary agent added relative to the mass fraction of the hydrogenation catalyst) can be 10% to 20%, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any combination thereof, which is beneficial to improve the conversion rate of IDAN and the selectivity of DETA, and increase the yield of DETA.

[0034] In the preparation of DETA described above, the solvent used may include a second organic solvent, specifically one or more of dioxane, tetrahydrofuran, methanol, ethanol, propanol, isopropanol, n-butanol, ethyl acetate, and butyl acetate, which helps to maintain the activity of the hydrogenation catalyst, improve the conversion rate of IDAN and the selectivity of DETA, and increase the yield of DETA.

[0035] In some embodiments, during the preparation of DETA described above, the mass ratio of IDAN to solvent (i.e., the mass fraction of IDAN in the solvent) can be 5% to 20%, for example, a range of 5%, 8%, 10%, 13%, 15%, 18%, 20%, or any combination thereof.

[0036] In this embodiment of the invention, a conventional reaction vessel in the art can be used for the hydrogenation reaction, such as a semi-batch reaction vessel.

[0037] Specifically, the conditions for the above hydrogenation reaction can be: a reaction temperature of 80℃ to 180℃, for example, 80℃, 100℃, 120℃, 140℃, 150℃, 170℃, 180℃ or any combination thereof; a hydrogen pressure of 3MPa to 8MPa, for example, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa or any combination thereof; and a reaction time of 60min to 300min, for example, 60min, 80min, 100min, 120min, 150min, 180min, 200min, 230min, 250min, 280min, 300min or any combination thereof, which is beneficial to improving the conversion rate of IDAN and the selectivity of DETA, and thus improving the yield of DETA.

[0038] Specifically, in the DETA preparation process described above, the amount of hydrogen added meets the aforementioned hydrogen pressure (i.e., hydrogen is introduced into the reactor and pressurized to a preset hydrogen pressure). In practice, hydrogen can be continuously fed.

[0039] Specifically, IDAN can be obtained from iminodiacetonitrile raw material (IDAN raw material) through pretreatment. The pretreatment process includes: extracting the iminodiacetonitrile raw material with an extractant to obtain iminodiacetonitrile; wherein the extractant includes water and a first organic solvent. By pretreating the IDAN raw material and extracting it with the above-mentioned extractant, impurities such as sulfuric acid and sulfates in IDAN can be removed, thereby facilitating the subsequent hydrogenation reaction of IDAN.

[0040] In this embodiment of the invention, the IDAN raw material can be obtained by conventional methods in the art, such as commercial purchase or self-production by conventional methods in the art.

[0041] Due to limitations in IDAN preparation processes, commercially available or self-prepared IDAN raw materials (or crude IDAN) using conventional methods in this field often contain trace amounts of sulfuric acid and sulfates, which are unsuitable for direct use as raw materials in hydrogenation reactions. By pre-treating (or purifying, removing impurities) the crude IDAN, trace amounts of sulfuric acid and sulfates are removed. The purified IDAN is then used as a raw material to carry out the above-mentioned hydrogenation reaction in a reaction system containing solvents, hydrogenation catalysts, and catalyst protectants to generate DETA. In other words, the IDAN used in the above-mentioned hydrogenation reaction (hereinafter referred to as purified IDAN) is obtained by purifying the crude IDAN through the above-mentioned pre-treatment process.

[0042] Specifically, the main acidic substances in crude IDAN are residual trace amounts of sulfuric acid and sulfates, which are impurities insoluble in organic solvents. By using the above-mentioned extractant for extraction and phase separation during the extraction process, the sulfuric acid and sulfates in the crude IDAN can be removed, and purified IDAN can be obtained. The purified IDAN can be directly used in the above-mentioned hydrogenation reaction to ensure the conversion rate of IDAN and the selectivity and yield of DETA.

[0043] Specifically, the first organic solvent may include one or more of dioxane, tetrahydrofuran, methanol, ethanol, propanol, isopropanol, n-butanol, ethyl acetate, and butyl acetate.

[0044] In some embodiments, the mass ratio of IDAN to the extractant (i.e., the mass fraction of IDAN in the extractant) can be 5% to 20%, for example, a range of 5%, 8%, 10%, 13%, 15%, 18%, 20%, or any combination thereof.

[0045] In some embodiments, the process of extracting crude IDAN using an extractant may include: mixing crude IDAN with an extractant, then adding an inorganic salt to promote phase separation, and then removing the organic phase (supernatant) to obtain an IDAN feedstock solution containing purified IDAN (i.e., purified IDAN is present in the IDAN feedstock solution). The inorganic salt reduces the solubility of water in the first organic solvent, thus facilitating phase separation. Specifically, the inorganic salt may include water-soluble inorganic salts, such as lithium hydroxide.

[0046] In practice, crude IDAN and the extractant can be mixed and thoroughly stirred to ensure homogeneity. Then, lithium hydroxide is added to promote phase separation (the upper layer is the organic phase, and the lower layer is the aqueous phase). After phase separation, the organic phase is removed using a separatory funnel or similar instrument. The organic phase is then filtered 2-4 times (e.g., 3 times) to remove impurities, yielding an IDAN feedstock solution containing purified IDAN. This IDAN feedstock solution can then be directly added to the above reaction system to react with hydrogen, generating DETA.

[0047] According to the inventor's research and analysis, purified IDAN is prone to decomposition at high temperatures to produce cyanide (CN). - This compound readily complexes with hydrogenation catalysts such as Raney cobalt, leading to catalyst loss and adsorption into catalyst pores, thus affecting catalyst activity and consequently impacting IDAN conversion and DETA selectivity. In this embodiment of the invention, within the aforementioned DETA preparation system, a weaker complex is introduced as a catalyst protectant. The organic groups in this catalyst protectant have a weaker ability to complex with metal elements than CN. - (For example, the carbonyl complexing ability of nickel carbonyl is worse than that of CN) - ), while the CN generated by IDAN - It has strong coordination ability and can exchange with organic groups in catalyst protectants to form corresponding complexes (usually liquid-phase products), thereby avoiding CN. - This mitigates the adverse effects on hydrogenation catalysts, thereby ensuring catalyst activity.

[0048] Specifically, the above-mentioned hydrogenation reaction process may include a first reaction stage and a second reaction stage. The first reaction stage is the continuous feeding stage of IDAN (specifically, the continuous feeding stage of IDAN feed liquid). The second reaction stage is the reaction stage after the continuous feeding of IDAN ends. That is, in the first reaction stage, IDAN (IDAN feed liquid) is continuously added to the reaction liquid system until the feeding of IDAN (IDAN feed liquid) is completed (that is, after all IDAN (IDAN feed liquid) has been added to the reaction liquid system), and the reaction is maintained under the preset reaction conditions for a preset time (i.e., the second reaction stage), and then the reaction is terminated to obtain DETA.

[0049] Specifically, the feed space velocity of the IDAN feed solution (i.e., the space velocity of the IDAN feed solution during the process of adding the IDAN feed solution to the reaction system) can be 1 to 5 g / min, for example, 1 g / min, 2 g / min, 3 g / min, 4 g / min, 5 g / min or any combination thereof.

[0050] In practice, solvents, hydrogenation catalysts, catalyst protectants, and additives can be added to the reactor to form a reaction liquid system. Then, the reactor is closed, and the air inside is replaced with an inert gas (e.g., 0.5 MPa to 0.7 MPa, approximately 0.6 MPa) 2 to 5 times (e.g., 3 times). Next, hydrogen (e.g., 0.8 to 1.2 MPa, approximately 1 MPa) is used to replace the inert gas inside the reactor, again 2 to 5 times (e.g., 3 times). Finally, hydrogen is introduced into the reactor. The hydrogen gas is pressurized to the preset reaction pressure, and the reactor is heated to the reaction temperature. IDAN is added to the reactor at a preset space velocity by means of pumping or other methods. Specifically, IDAN feed solution can be added to carry out the hydrogenation reaction (the first reaction stage is carried out first, and after the IDAN feed is completed, the preset time is maintained (i.e., the second reaction stage is carried out)). After the hydrogenation reaction is completed, the temperature in the reactor is cooled to room temperature, and the reaction solution in the reactor is filtered to obtain a filtrate containing DETA. DETA can then be further separated and purified as needed.

[0051] For example, filtrates containing DETA generally contain piperazine in addition to DETA. In practice, DETA and piperazine can be separated by methods such as vacuum distillation as needed.

[0052] Specifically, the DETA preparation process described above generally also produces piperazine as a byproduct. That is, after the hydrogenation reaction is completed, the reaction solution in the reactor contains piperazine. After filtering the reaction solution, the filtrate containing DETA also contains piperazine. After obtaining the filtrate containing DETA, parameters such as the conversion rate of IDAN, the yield (selectivity) of DETA, and the yield (selectivity) of piperazine can be analyzed by methods such as gas chromatography.

[0053] In this embodiment of the invention, the above-described DETA preparation process can improve the conversion rate of IDAN (which can basically reach 100%) and the DETA selectivity (not less than 80%, especially more than 85% or even more than 90%), and reduce the selectivity of by-products such as piperazine (the selectivity of piperazine is less than 7%, generally 3% to 7%).

[0054] In this embodiment of the invention, the catalytic activity of the hydrogenation catalyst can be maintained through the above-described DETA preparation process, thus avoiding deactivation of the hydrogenation catalyst, improving the service life of the hydrogenation catalyst, and facilitating the stable and continuous production of DETA.

[0055] Specifically, the hydrogenation catalyst can be reused multiple times (i.e., the hydrogenation catalyst can be reused multiple times according to the DETA preparation process described above). That is, after performing the hydrogenation reaction described above once, the hydrogenation catalyst can be separated from the reaction solution and used again as a hydrogenation catalyst for the above hydrogenation reaction, and so on, for multiple reuses. After multiple reuses, the hydrogenation catalyst can still maintain high catalytic activity. For example, after five reuses, it can still maintain a high conversion rate of IDAN (above 50%, especially above 87%) and a high selectivity of DETA (above 85%, even above 90%).

[0056] The present invention will be further described below through specific embodiments.

[0057] Unless otherwise specified, the IDAN (i.e., IDAN raw material), dioxane, lithium hydroxide, and Raney nickel (Raney cobalt catalyst) used in the following examples or comparative examples are from Innovent Technology Co., Ltd., and the others are ordinary commercially available raw materials.

[0058] In the following examples and comparative examples, the gas chromatography analysis conditions were as follows: an Agilent 7890 and DB-5 (30mm*0.25mm*0.25μm) column were used, the injector temperature was 280℃, and the detector temperature was 300℃. The temperature program was as follows: initial column temperature was 50℃, held for 2 min; temperature was increased to 80℃ at 5℃ / min, held for 0 min; temperature was increased to 300℃ at 15℃ / min, held for 15 min; the content of each component was determined by normalization, and the IDAN conversion rate, DETA yield, and piperazine yield were measured.

[0059] Example 1

[0060] S1. Pretreatment of crude IDAN (IDAN raw material)

[0061] Mix 100g of crude IDAN, 240g of water and 350g of dioxane (the first organic solvent), stir and shake thoroughly, and add 5g of lithium hydroxide to promote phase separation. After phase separation, use a separatory funnel to remove the upper liquid (organic phase), filter the upper liquid three times to remove impurities, and obtain the IDAN feed solution.

[0062] S2, hydrogenation reaction

[0063] Add 10g of Raney cobalt, 200g of dioxane (second organic solvent), 1.5g of LiOH, and 0.5g of nickel carbonyl to the reactor. Close the reactor and purge the air inside three times with nitrogen at 0.6MPa, then purge the nitrogen inside three times with hydrogen at 1MPa. Pressurize the hydrogen to 5MPa, turn on the heater, and heat to a reaction temperature of 130℃. Continuously pump 200g of IDAN feed solution (IDAN mass concentration of 15%wt) into the reactor at a space velocity of 3g / min for the first stage reaction. After the feed is completed, maintain for 30min (i.e., the second stage reaction) and then stop the reaction. After the temperature inside the reactor drops to room temperature, filter the reaction solution in the reactor to obtain a filtrate containing DETA. The filtration is carried out in the reactor under nitrogen. The obtained liquid (the filtrate containing DETA) is discharged from the reactor through the bottom tube, while the solid (mainly Raney nickel) remains in the reactor for subsequent recycling.

[0064] Gas chromatography analysis of the filtrate containing DETA showed that the IDAN conversion rate was 100%, the DETA yield was 93%, and the piperazine yield was 5% in the first batch (i.e., the first use of the hydrogenation catalyst).

[0065] (3) The Raney cobalt was reused 5 times (that is, after using Raney cobalt as a hydrogenation catalyst, after completing step S2 once, the Raney cobalt separated from the reaction liquid in step S2 was used as a hydrogenation catalyst to repeat step S2 (i.e., the second reuse), and so on, until it was reused 5 times. As mentioned in step S2, 0.5 g of carbonyl nickel was added as a catalyst protectant in each batch). The IDAN conversion rate of the 5th batch (i.e. the 5th reuse of the hydrogenation catalyst) was 100%, the DETA yield was 92.5%, and the piperazine yield was 5%.

[0066] Examples 2 to 8: The difference from Example 1 is that the first organic solvent in step S1, the second organic solvent in step S2, the type and amount of catalyst protectant are different, as shown in Table 1. Except for the differences shown in Table 1, the other steps and conditions are the same.

[0067] Comparative Example 1

[0068] S1. Preprocessing of crude IDAN

[0069] Mix 100g of crude IDAN and 590g of dioxane, stir and shake thoroughly, and filter three times to remove impurities to obtain IDAN raw material solution.

[0070] S2, Hydrogenation reaction: The difference from step S2 (hydrogenation reaction) in Example 1 is that the second solvent is tetrahydrofuran, and the other conditions are the same as in Example 1.

[0071] Comparative Example 2

[0072] S1. Pretreatment of crude IDAN: Same as step S1 (pretreatment of crude IDAN) in Example 1.

[0073] The difference between step S2 (hydrogenation reaction) in Example 1 and step S2 (hydrogenation reaction) is that no catalyst protectant is added, and the second organic solvent used is tetrahydrofuran (i.e., in Comparative Example 2, 10g of Raney cobalt is added to the reactor, along with 200g of tetrahydrofuran and 1.5g of LiOH, and then the reactor is closed to proceed with the subsequent process).

[0074] Table 1 shows the conditions, such as the type and amount of the first organic solvent, the second organic solvent, the catalyst protectant, and the reaction results (IDAN conversion, DETA selectivity, and piperazine selectivity for the first and fifth batches) in each example and comparative example.

[0075] Table 1. Preparation conditions and reaction results of DETA

[0076]

[0077] As can be seen from Table 1, in Examples 1 to 8, after extracting the IDAN raw material with water and organic solvent, the IDAN was then subjected to a hydrogenation reaction. Furthermore, a catalyst protectant was introduced into the hydrogenation reaction system, which could simultaneously improve the conversion rate of IDAN and the yield of DETA, reduce the yield of piperazine, and improve the service life of the hydrogenation catalyst.

[0078] In contrast to Comparative Example 1 (which used organic solvents to pretreat IDAN feedstock), Examples 4 to 9 used water and organic solvents as extractants to pretreat IDAN feedstock, which significantly improved the conversion rate of IDAN and the yield of DETA, while also reducing the yield of piperazine and improving the service life of the hydrogenation catalyst.

[0079] Compared to Comparative Example 2 (no catalyst protectant was added during the hydrogenation reaction), Examples 4 to 9 introduced a catalyst protectant during the hydrogenation reaction, which significantly improved the service life of the hydrogenation catalyst. Even when used in the 5th batch, it could still maintain a high conversion rate of IDAN and a yield of DETA, while also reducing the yield of piperazine.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for the preparation of N 1 characterized in that, Includes the following steps: reacting imino-diacetonitrile with hydrogen gas in a reaction fluid system containing a solvent, a hydrogenation catalyst, and a catalyst protectant to form N 1 -(2-aminoethyl)-1,2-ethanediamine; wherein the catalyst protectant is selected from one or more of nickel carbonyl, iron carbonyl, nickel tetraamine, and cobalt tetraamine. The iminodiacetonitrile is obtained by pretreatment of iminodiacetonitrile raw material. The pretreatment process includes: extracting the iminodiacetonitrile raw material with an extractant to obtain the iminodiacetonitrile; wherein the extractant is water and a first organic solvent, the first organic solvent being selected from dioxane and / or tetrahydrofuran.

2. The N 1 Process for the preparation of (2-aminoethyl)-1,2-ethanediamine, characterized in that, The hydrogenation catalyst is selected from one or more of Raney nickel and Raney cobalt.

3. The N according to claim 1 or 2 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The mass ratio of the hydrogenation catalyst to the iminodiacetonitrile is 5% to 40%.

4. The N according to claim 1 or 2 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The mass ratio of the catalyst protectant to the hydrogenation catalyst is 1% to 10%.

5. The N according to claim 1 or 2 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The reaction solution system also includes an auxiliary agent selected from metal oxides and / or metal hydroxides.

6. The N according to claim 5 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The metal element in the metal oxide is selected from alkali metals and / or alkaline earth metals, and the metal element in the metal hydroxide is selected from alkali metals and / or alkaline earth metals.

7. The N according to claim 5 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The mass ratio of the auxiliary agent to the hydrogenation catalyst is 10% to 20%.

8. The N 1 Process for the preparation of (2-aminoethyl)-1,2-ethanediamine, characterized in that, The alkali metal includes lithium and / or potassium. And / or, the alkaline earth metal includes calcium.

9. The N according to claim 1 or 2 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The solvent is selected from one or more of dioxane, tetrahydrofuran, methanol, propanol, isopropanol, n-butanol, ethyl acetate, and butyl acetate.

10. The N according to claim 1 or 2 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The reaction conditions are as follows: reaction temperature is 80℃~180℃, hydrogen pressure is 3 MPa~8 MPa, and reaction time is 60min~300min.

11. The N according to claim 1 or 2 1 The method for preparing 1,2-(2-aminoethyl)-1,2-ethylenediamine is characterized by, The pretreatment process includes: extracting the iminodiacetonitrile raw material with an extractant to obtain a raw material liquid containing the iminodiacetonitrile; The process of reacting imino-bis-acetonitrile with hydrogen gas in a reaction liquid system containing a solvent, a hydrogenation catalyst, and a catalyst protective agent includes: adding a raw material liquid containing the imino-bis-acetonitrile to the reaction liquid system, and reacting the imino-bis-acetonitrile with hydrogen gas to produce the N 1 -(2-aminoethyl)-1,2-ethanediamine; wherein, in the process of adding the raw material liquid containing the imino-bis-acetonitrile to the reaction liquid system, the space velocity of the raw material liquid containing the imino-bis-acetonitrile is 1 to 5 g / min.

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