Preparation method of diethylenetriamine

Abstract

The invention relates to a preparation method of diethylenetriamine, which comprises the following steps: by taking dehydrated IDAN as a raw material, dissolving IDAN in a solvent, and carrying out two-stage reaction on IDAN and hydrogen under the action of a hydrogenation catalyst to generate DETA. Compared with the prior art, the scheme provided by the invention reduces the yield of piperazine, and ensures the purity of the product and the high efficiency of the process.

Description

Technical Field

[0001] The invention relates to a method for preparing diethylenetriamine, and belongs to the field of amine compound synthesis. Background Art

[0002] N 1 -(2-aminoethyl)-1,2-ethylenediamine, referred to as DETA, also known as diethylenetriamine, English name: Diethylenetriamine, is a yellow, hygroscopic, transparent, viscous liquid with a pungent ammonia odor, and easily absorbs moisture and carbon dioxide in the air. Diethylenetriamine is mainly used in the synthesis of polyamide resins, paper reinforcing agents, metal chelating agents, surfactants, lubricants, epoxy resin curing agents, etc.

[0003] At present, DETA is mainly produced by the ethylene dichloride (EDC) amination method or the ethanolamine (MEA) method. The characteristic of the EDC method is that the reaction process can be carried out without the use of a catalyst, and it is a fast, exothermic reaction. Since the main product EDA has stronger alkalinity and nucleophilicity than the raw material NH3, it is very easy to participate in the reaction as an intermediate product to trigger a series of reactions to generate DETA or other polyethylene polyamines. Therefore, the products obtained by the EDC method are widely distributed, mainly linear polyethylene polyamines. The EDC method has the advantages of easy availability of raw materials, no need for catalysts, high flexibility and wide distribution of product composition. It has been an important process for producing ethyleneamines abroad for a long time. However, the EDC method faces problems such as high energy consumption in the production process, severe equipment corrosion and high cost. In particular, with the increasingly stringent environmental protection requirements in the chemical production process, the serious three wastes problem of the EDC method has further increased the cost of treatment. The above shortcomings limit the promotion of the EDC method in today's chemical production.

[0004] MEA hydroamination, also known as MEA reductive amination or direct amination, refers to the process in which raw materials MEA and NH3 react under the action of a catalyst and in an H2 atmosphere to generate amine products and water. Among them, the main amine product is EDA, and high-value-added DETA, PIP and piperazine derivatives are by-products. MEA hydroamination is a gas-liquid-solid three-phase reaction. The catalyst used is a dehydrogenation-hydrogenation catalyst composed of transition metals. The reaction temperature and pressure are usually in the range of 150-200℃ and 3-30MPa. The reactor used can be an autoclave or fixed bed reactor. At present, the process of producing DETA using MEA as raw material has received more and more attention. The MEA process route has low investment, low environmental pollution and low energy consumption, which is in line with the development trend of green chemistry. However, the MEA process still has the disadvantages of high reaction temperature and easy carbon deposition and deactivation of the catalyst, and the current cost of ethylenediamine raw materials is relatively high, which is not economical.

[0005] The advantages of preparing corresponding organic amines by hydrogenation of nitriles are increasingly highlighted because of its simple process and environmentally friendly process. US2002058842 mentions that the hydrogenation reaction of iminodiacetonitrile (IDAN) is carried out in the system of N,N-dimethylformamide (DMF) with a reaction temperature of 100°C, a reaction pressure of 190 bar, Raney cobalt as a catalyst, and a DETA selectivity of 82%. WO2008104583A1 introduces a method for preparing DETA by hydrogenating a mixture of IDAN and aminoacetonitrile in tetrahydrofuran as a solvent. Since aminoacetonitrile is easy to polymerize and decompose at room temperature, the product composition in the reaction solution is complex and changeable, which affects the subsequent separation of DETA. In addition, the CN decomposed by aminoacetonitrile - It will also lead to reduced catalyst activity or even deactivation, which will have an adverse effect on the reaction.

[0006] The presence of a certain amount of moisture in the IDAN raw material can increase the activity of the hydrogenation catalyst, but will lead to an increase in the proportion of piperazine products. In addition, the moisture in the raw material will cause IDAN to hydrolyze to form iminodiacetic acid, resulting in a catalytic system that is acidic and increases piperazine. At the same time, since the hydrogenation of IDAN to the intermediate product is a fast reaction, while the intermediate product to DETA and piperazine is a slow reaction, this patent uses a two-stage reaction to increase the yield of DETA and reduce the yield of piperazine. Summary of the invention

[0007] The object of the present invention is to provide a method for preparing DETA from IDAN, which comprises the following steps: using dehydrated IDAN as a raw material, dissolving IDAN in a solvent and reacting with hydrogen under the action of a hydrogenation catalyst to generate DETA through a two-stage reaction.

[0008] In the present invention, the water content of the IDAN after dehydration is 100-1000ppm;

[0009] The solvent is selected from one or more of dioxane, tetrahydrofuran, methanol, ethanol, propanol, isopropanol, n-butanol, ethyl acetate, and butyl acetate.

[0010] The hydrogenation catalyst is selected from a metal catalyst and / or a supported catalyst, the metal catalyst is selected from Raney nickel and / or Raney cobalt, the supported catalyst comprises a carrier, and an active component supported on the carrier, the carrier comprises one or more of aluminum oxide, silicon oxide, titanium oxide, and molecular sieves, and the active component comprises one or more of cobalt, nickel, platinum, iron, palladium, and ruthenium.

[0011] The mass fraction of IDAN in the solvent is 5-20%, and the hydrogen is fed continuously.

[0012] The reaction temperature of one stage of the reaction is 120-140°C, the reaction time is 10-30min, and the hydrogen pressure is 3-8MPa.

[0013] The reaction temperature of the second stage reaction is 10-30°C lower than the reaction temperature of the first stage reaction, the reaction time is 30-60min, and the hydrogen pressure is 3-8MPa.

[0014] When the second stage reaction starts, a mixture of piperazine and water is pumped into the reactor, the mass ratio of piperazine to water is 1:1-2:1, and the mixture of piperazine and water accounts for 0.5-5% of the mass of the IDAN raw material liquid in the kettle.

[0015] After the reaction was completed, the temperature in the autoclave was cooled to room temperature, and the reaction liquid was filtered out for gas chromatography analysis.

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

[0017] The reaction reduces piperazine through two-stage reactions. The first stage of the reaction reduces the reaction time, increases the reaction temperature, and generates as many intermediate products as quickly as possible. The second stage of the reaction reduces the piperazine yield by lowering the temperature and increasing the cyclic product. DETAILED DESCRIPTION

[0018] Raw materials and sources: The main raw materials used in the following examples or comparative examples were purchased from Inotech, and the others were common commercially available raw materials unless otherwise specified.

[0019] Test method: The conditions for gas chromatography analysis in the following examples are: Agilent 7890 and DB-5 (30mm*0.25mm*0.25μm), injector temperature is 280℃, detector temperature is 300℃. The heating program is as follows: the initial column temperature is 50℃, maintained for 2min; the temperature is increased to 80℃ at 5℃ / min, maintained for 0min; the temperature is increased to 300℃ at 15℃ / min, maintained for 15min. The content of each component is determined by normalization method.

[0020] Example 1

[0021] Raw material pretreatment process: Add 100g of crude IDAN and 200g of anhydrous dioxane at 40°C, stir and dissolve. Filter the solution three times, crystallize at 15°C for 10h, and filter out the crystalline solid for later use. Dissolve 100g of the crystalline solid in 500g of dioxane, add 2g of anhydrous calcium chloride, stir for 10min, and filter. Add 1g of 4A molecular sieve to the filtrate, stir for 10min, and continue to filter. The filtrate is named IDAN raw material solution, and the water content is 500ppm.

[0022] Reaction process: Add 10g of Raney cobalt catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, use 0.6MPa nitrogen to replace the air in the reactor three times, and then use 1MPa hydrogen to replace the nitrogen in the reactor three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Pump in a mixture of 5g water and 5g piperazine. Lower the reaction temperature to 120℃, keep it for 60min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis, where the IDAN conversion rate is 100%, the DETA selectivity is 95%, and the piperazine selectivity is 2%.

[0023] Example 2

[0024] The raw material pretreatment process is the same as shown in Example 1.

[0025] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 150℃, and keep it for 20min. Pump in a mixture of 5g of water and 5g of piperazine. Lower the reaction temperature to 120℃, keep it for 60min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0026] Example 3

[0027] The raw material pretreatment process is the same as shown in Example 1.

[0028] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 40min. Pump in a mixture of 5g of water and 5g of piperazine. Lower the reaction temperature to 120℃, keep it for 60min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0029] Example 4

[0030] The raw material pretreatment process is the same as shown in Example 1.

[0031] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Pump in a mixture of 5g of water and 5g of piperazine. Lower the reaction temperature to 110℃, keep it for 60min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0032] Example 5

[0033] The raw material pretreatment process is the same as shown in Example 1.

[0034] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 120℃, and keep it for 20min. Pump in a mixture of 5g of water and 5g of piperazine. Keep the reaction temperature at 120℃ for 60min and then end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0035] Example 6

[0036] The raw material pretreatment process is the same as shown in Example 1.

[0037] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Pump in a mixture of 5g of water and 5g of piperazine. Lower the reaction temperature to 120℃, keep it for 40min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0038] Example 7

[0039] The raw material pretreatment process is the same as shown in Example 1.

[0040] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Pump in a mixture of 5g of water and 5g of piperazine. Lower the reaction temperature to 120℃, keep it for 80min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0041] Example 8

[0042] The raw material pretreatment process is the same as shown in Example 1.

[0043] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Pump in a mixture of 10g of water and 5g of piperazine. Lower the reaction temperature to 120℃, keep it for 60min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0044] Comparative Example 1

[0045] The raw material pretreatment process is the same as shown in Example 1.

[0046] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Pump in a mixture of 5g of water and 5g of piperazine. Keep the reaction temperature at 130℃ for 60min and then end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0047] Comparative Example 2

[0048] The raw material pretreatment process is the same as shown in Example 1.

[0049] Reaction process: Add 10g of catalyst and 300g of IDAN raw material liquid into the reactor. Close the reactor, replace the air in the reactor with 0.6MPa nitrogen three times, and then replace the nitrogen in the reactor with 1MPa hydrogen three times. Pressurize the hydrogen to 5MPa, open the reactor and heat to the reaction temperature of 130℃, and keep it for 20min. Do not pump in water and piperazine. Lower the reaction temperature to 120℃, keep it for 60min and end the reaction. When the temperature in the reactor drops to room temperature, filter out the reaction liquid for gas chromatography analysis.

[0050] Preparation conditions and reaction results of DETA

[0051]

Claims

1. A method for preparing diethylenetriamine, the method comprising the following steps: using dehydrated IDAN as a raw material, dissolving IDAN in a solvent and reacting with hydrogen under the action of a hydrogenation catalyst to generate DETA through a two-stage reaction.

2. The method according to claim 1, characterized in that The water content of the IDAN after dehydration is 100-1000 ppm.

3. The method according to claim 1 or 2, characterized in that The solvent is selected from one or more of dioxane, tetrahydrofuran, methanol, ethanol, propanol, isopropanol, n-butanol, ethyl acetate and butyl acetate; and / or the mass fraction of IDAN in the solvent is 5-20%.

4. The method according to any one of claims 1 to 3, characterized in that: The hydrogenation catalyst is selected from a metal catalyst and / or a supported catalyst. Preferably, the metal catalyst is selected from Raney nickel and / or Raney cobalt. The supported catalyst comprises a carrier and an active component supported on the carrier. The carrier comprises one or more of aluminum oxide, silicon oxide, titanium oxide, and molecular sieves. The active component comprises one or more of cobalt, nickel, platinum, iron, palladium, and ruthenium.

5. The method according to any one of claims 1 to 4, characterized in that: The reaction temperature of one of the two-stage reactions is 120-140° C., the reaction time is 10-30 min, and the hydrogen pressure is 3-8 MPa.

6. The method according to any one of claims 1 to 5, characterized in that: The reaction temperature of the second stage reaction in the two-stage reaction is 10-30° C. lower than the reaction temperature of the first stage reaction, the reaction time is 30-60 min, and the hydrogen pressure is 3-8 MPa.

7. The method according to any one of claims 1 to 6, characterized in that: When the second stage reaction in the two-stage reaction starts, a mixture of piperazine and water is pumped into the reactor, and the mass ratio of piperazine to water is 1:1-2:1; and / or the mixture of piperazine and water accounts for 0.5-5% of the mass of the IDAN raw material liquid in the kettle.

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